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Simple Summary: Most cancer patients are older and have concomitant diseases because the incidence of most cancer types increases with age. This leads to patients taking a variety of medications that can cause drug-related problems (DRPs). DRPs can cause harm, including increased illness, avoidable hospital stays, and even death. Common DRPs are drug–drug interactions, not taking medication as prescribed, and adverse drug reactions. In our study, we aimed to assess these medication risks in hospitalized cancer patients and to identify factors that influence their health-related quality of life (HRQOL) as a patient-relevant outcome. The results of the pharmacist-led medication reviews show that DRPs are common in hospitalized cancer patients. Therefore, patient questionnaires about therapy-related symptoms could improve the detection of DRPs. While drug-related factors had no effect on HRQOL during the hospital stay, our analysis revealed other influencing factors, such as relapse status of the cancer disease and length of hospital stay. Background: We aimed to assess medication risks and determine factors influencing the health-related quality of life (HRQOL) in cancer inpatients. Methods: A retrospective analysis was conducted to identify drug-related problems (DRPs) based on medication reviews, including patient-reported outcomes (PROs). Multiple linear regression analyses were performed to identify sociodemographic, disease-related, and drug therapy-related factors influencing changes from hospital admission to discharge in the scales of the EORTC QLQ-C30 questionnaire. Results: A total of 162 inpatients with various hematological and solid cancer diseases was analyzed. Patients received a mean of 11.6 drugs and 92.6% of patients exhibited polymedication resulting in a mean of 4.0 DRPs per patient. Based on PRO data, 21.5% of DRPs were identified. Multiple linear regression models described the variance of the changes in global HRQOL and physical function in a weak-to-moderate way. While drug therapy-related factors had no influence, relapse status and duration of hospital stay were identified as significant covariates for global HRQOL and physical function, respectively. Conclusion: This analysis describes underlying DRPs in a German cancer inpatient population. PROs provided valuable information for performing medication reviews. The multiple linear regression models for global HRQOL and physical function provided explanations for changes during hospital stay. [ABSTRACT FROM AUTHOR]

Simple Summary: The United States is suffering from an epidemic associated with infections with the Human Papilloma Virus (HPV) that are responsible for the development of head and neck squamous cell carcinoma (HNSCC). Our study aims to characterize immune profiles, and the oral microbiota in oropharyngeal tumors associated with anti-PD-1 treatment response in a preclinical murine model for HPV+ oropharyngeal cancer. We confirmed 16 immune markers and specific bacteria in the oral cavity that differentiate between treatment responders and non-responders, which may be used as potential biomarkers for PD-1 blockade response. The United States is suffering from an epidemic associated with high-risk strains of the Human Papillomavirus (HPV) predominantly responsible for the development of head and neck squamous cell carcinoma (HNSCC). Treatment with immune checkpoint inhibitors targeting programmed death 1 (PD-1) or its ligand PD-L1 has shown poor efficacy in HNSCC patients, observing only a 20–30% response. Therefore, biological marker identification associated with PD-1 blockade response is important to improve prognosis and define novel therapeutics for HNSCC patients. Therapy response was associated with increased frequencies of activated CD27+T cells, activated CD79a+ B cells, antigen-presenting CD74+ dendritic and B cells, and PD-L1+ and PD-L2+ myeloid-derived suppressor cells (MDSCs). The oral microbiota composition differed significantly in mice bearing tongue tumors and treated with anti-PD-1. A higher abundance of Allobaculum, Blautia, Faecalibacterium, Dorea, or Roseburia was associated with response to the therapy. However, an increase in Enterococcus was attributed to tongue tumor-bearing non-responding mice. Our findings indicate that differences in immune phenotypes, protein expression, and bacterial abundance occur as mice develop tongue tumors and are treated with anti-PD-1. These results may have a clinical impact as specific bacteria and immune phenotype could serve as biomarkers for treatment response in HNSCC. [ABSTRACT FROM AUTHOR]

Simple Summary: Chronic inflammation is one of the major risk factors for colorectal cancer development. This study aims to determine the effect of genetic mutations on inflammation-induced colon tumor cell heterogeneity and differentiation. Using single-cell approaches, we found that the addition of BRAFV600E to Apc mutant mice (BLM) increased colon epithelial tumor differentiation. Additionally, we found that BLM epithelial tumors had increased expression of revival colon stem cell (RevCSC) markers and reduced WNT signaling compared to Apc mutant epithelial tumors (Min). In contrast, the loss of Msh2 in Min mice (MSH2KO) increased epithelial tumor stem cell populations with increased WNT signaling compared to Min epithelial tumor. We also identified additional potential regulators of BLM epithelial tumor differentiation such as CDX2 and NDRG1. Genetic mutations and chronic inflammation of the colon contribute to the development of colorectal cancer (CRC). Using a murine model of inflammation-induced colon tumorigenesis, we determined how genetic mutations alter colon tumor cell differentiation. Inflammation induced by enterotoxigenic Bacteroides fragilis (ETBF) colonization of multiple intestinal neoplasia (MinApcΔ716/+) mice triggers loss of heterozygosity of Apc causing colon tumor formation. Here, we report that the addition of BRAFV600E mutation (BRAFF-V600ELgr5tm1(Cre/ERT2)CleMinApcΔ716/+, BLM) or knocking out Msh2 (Msh2LoxP/LoxPVil1-creMinApcΔ716/+, MSH2KO) in the Min model altered colon tumor differentiation. Using single-cell RNA sequencing, we uncovered the differences between BLM, Min, and MSH2KO tumors at a single-cell resolution. BLM tumors showed an increase in differentiated tumor epithelial cell lineages and a reduction in the tumor stem cell population. Interestingly, the tumor stem cell population of BLM tumors had revival colon stem cell characteristics with low WNT signaling and an increase in RevCSC marker gene expression. In contrast, MSH2KO tumors were characterized by an increased tumor stem cell population that had higher WNT signaling activity compared to Min tumors. Furthermore, overall BLM tumors had higher expression of transcription factors that drive differentiation, such as Cdx2, than Min tumors. Using RNA velocity, we identified additional potential regulators of BLM tumor differentiation such as NDRG1. The role of CDX2 and NDRG1 as putative regulators for BLM tumor cell differentiation was verified using organoids derived from BLM tumors. Our results demonstrate the critical connections between genetic mutations and cell differentiation in inflammation-induced colon tumorigenesis. Understanding such roles will deepen our understanding of inflammation-associated colon cancer. [ABSTRACT FROM AUTHOR]

Simple Summary: Mutation of the SMARCB1 gene can cause one of the most aggressive and lethal cancers of early childhood and infancy, malignant rhabdoid tumor (MRT). Despite the standard multimodal therapy (resection, conventional chemotherapy, and radiotherapy), the outlook for young children with MRT is poor. For infants, the disease can also preclude the use of radiotherapy. Numerous experimental treatments explore epigenetic mechanisms, but the DNA damage response has not yet been extensively evaluated as a therapeutic approach for MRT. We report a new therapeutic strategy for SMARCB1-deficient MRTs, combining PARP1 inhibition and DNA damage induction. The observed synergy between the PEGylated PARP1 inhibitor talazoparib (PEG~TLZ) and the DNA alkylating agent temozolomide (TMZ) may lead to improved therapeutic strategies for patients with this challenging cancer. We identified a new potential biomarker of response to PEG~TLZ+TMZ, O6-methylguanine methyltransferase (MGMT), and uncovered dysregulated signaling pathways involved in the response. Additionally, we elucidated the pro-survival role of SMARCB1 loss in MRT cells. Malignant rhabdoid tumors (MRTs) are among the most aggressive and treatment-resistant malignancies affecting infants, originating in the kidney, brain, liver, and soft tissues. The 5-year event-free survival rate for these cancers is a mere 20%. In nearly all cases of MRT, the SMARCB1 gene (occasionally SMARCA4)—a pivotal component of the SWI/SNF chromatin remodeling complex—is homozygously deleted, although the precise etiology of these tumors remains unknown. While young patients with localized MRT generally show improved outcomes, especially those who are older and have early-stage disease, the overall prognosis remains poor despite optimal standard treatments. This highlights the urgent need for more effective treatment strategies. We investigated the antitumor activity of a PARP1 inhibitor (talazoparib, TLZ) combined with a DNA alkylating agent (temozolomide, TMZ) in MRT xenograft models. PARP1 is a widely targeted molecule in cancer treatment and, beyond its role in DNA repair, it participates in transcriptional regulation by recruiting chromatin remodeling complexes to modulate DNA accessibility for RNA polymerases. To widen the therapeutic window of the drug combination, we employed PEGylated TLZ (PEG~TLZ), which has been reported to reduce systemic toxicity through slow drug release. Remarkably, our findings indicate that five out of six MRT xenografts exhibited an objective response to PEG~TLZ+TMZ therapy. Significantly, the loss of SMARCB1 was found to confer a protective effect, correlating with higher expression levels of DNA damage and repair proteins in SMARCB1-deficient MRT cells. Additionally, we identified MGMT as a potential biomarker indicative of in vivo MRT response to PEG~TLZ+TMZ therapy. Moreover, our analysis revealed alterations in signaling pathways associated with the observed antitumor efficacy. This study presents a novel and efficacious therapeutic approach for MRT, along with a promising candidate biomarker for predicting tumor response. [ABSTRACT FROM AUTHOR]

Simple Summary: Inconsistent engraftment of luciferase-expressing tumors, especially GL261 Red-FLuc, has been reported in the recent literature. However, techniques to improve tumor take have not been described. Our study aimed to optimize two luciferase-expressing mouse glioblastoma models, GL261 Red-FLuc and TRP-mCherry-FLuc, which revealed differences in tumor development and characteristics. While the features of each tumor were distinct, with GL261 Red-FLuc tumors showing high mitotic activity and vascularization and TRP-mCherry-FLuc tumors displaying necrosis and invasiveness, each exhibited features reminiscent of patients with glioblastoma. Furthermore, we developed a method for high-throughput sample analysis by quantifying the luciferase-positive tumor volume using artificial intelligence. Our findings provide valuable insights for researchers using similar models, emphasizing the need to consider tumor engraftment for robust preclinical research. Glioblastoma (GBM) is the most aggressive brain cancer. To model GBM in research, orthotopic brain tumor models, including syngeneic models like GL261 and genetically engineered mouse models like TRP, are used. In longitudinal studies, tumor growth and the treatment response are typically tracked with in vivo imaging, including bioluminescence imaging (BLI), which is quick, cost-effective, and easily quantifiable. However, BLI requires luciferase-tagged cells, and recent studies indicate that the luciferase gene can elicit an immune response, leading to tumor rejection and experimental variation. We sought to optimize the engraftment of two luciferase-expressing GBM models, GL261 Red-FLuc and TRP-mCherry-FLuc, showing differences in tumor take, with GL261 Red-FLuc cells requiring immunocompromised mice for 100% engraftment. Immunohistochemistry and MRI revealed distinct tumor characteristics: GL261 Red-FLuc tumors were well-demarcated with densely packed cells, high mitotic activity, and vascularization. In contrast, TRP-mCherry-FLuc tumors were large, invasive, and necrotic, with perivascular invasion. Quantifying the tumor volume using the HALO® AI analysis platform yielded results comparable to manual measurements, providing a standardized and efficient approach for the reliable, high-throughput analysis of luciferase-expressing tumors. Our study highlights the importance of considering tumor engraftment when using luciferase-expressing GBM models, providing insights for preclinical research design. [ABSTRACT FROM AUTHOR]

Simple Summary: In order to grow, tumors need nutrients and oxygen, which are supplied by new blood vessels that are often abnormal and leaky. The development of these blood vessels is driven by proteins called growth factors, which bind to receptor proteins on other cells. We show for the first time that an antibody against a vascular growth factor called VEGF-B, when used to treat mice with tumors, reduces the amount of abnormal tumor blood vessels, and inhibits tumor growth, as well as improving the response to chemotherapy. These results suggest that targeting VEGF-B could be a potential approach for anti-cancer therapy, particularly in combination with chemotherapy. The vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) are key regulators of blood vessel formation, including in tumors, where their deregulated function can promote the production of aberrant, leaky blood vessels, supporting tumor development. Here we investigated the VEGFR1 ligand VEGF-B, which we demonstrate to be expressed in tumor cells and in tumor stroma and vasculature across a range of tumor types. We examined the anti-VEGF-B-specific monoclonal antibody 2H10 in preclinical xenograft models of breast and colorectal cancer, in comparison with the anti-VEGF-A antibody bevacizumab. Similar to bevacizumab, 2H10 therapy was associated with changes in tumor blood vessels and intra-tumoral diffusion consistent with normalization of the tumor vasculature. Accordingly, treatment resulted in partial inhibition of tumor growth, and significantly improved the response to chemotherapy. Our studies indicate the importance of VEGF-B in tumor growth, and the potential of specific anti-VEGF-B treatment to inhibit tumor development, alone or in combination with established chemotherapies. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic ductal adenocarcinoma continues to be one of the deadliest cancers worldwide. Preclinical studies involving animals rarely include sex as a major biological variable in testing the efficacy of new drugs. In an animal model of pancreatic cancer, we analyzed the impact of sex on the pathological features of the disease and on an experimental small molecule-based therapy tested in vivo for the first time. While the therapy shows potential, the obtained results are confounded by sex-specific effects. This study, therefore, highlights the importance of sex-inclusive research while simultaneously providing a basis for further studies of the therapy tested. Preclinical studies rarely test the efficacy of therapies in both sexes. The field of oncology is no exception in this regard. In a model of syngeneic, orthotopic, metastasized pancreatic ductal adenocarcinoma we evaluated the impact of sex on pathological features of this disease as well as on the efficacy and possible adverse side effects of a novel, small molecule-based therapy inhibiting KRAS:SOS1, MEK1/2 and PI3K signaling in male and female C57BL/6J mice. Male mice had less tumor infiltration of CD8-positive cells, developed bigger tumors, had more lung metastasis and a lower probability of survival compared to female mice. These more severe pathological features in male animals were accompanied by higher distress at the end of the experiment. The evaluated inhibitors BI-3406, trametinib and BKM120 showed synergistic effects in vitro. This combinatorial therapy reduced tumor weight more efficiently in male animals, although the drug concentrations were similar in the tumors of both sexes. These results underline the importance of sex-specific preclinical research and at the same time provide a solid basis for future studies with the tested compounds. [ABSTRACT FROM AUTHOR]

Simple Summary: Selecting and developing effective therapies for distinct epithelial ovarian cancer subtypes necessitates tumor models that accurately recapitulate the individual characteristics and microenvironmental interactions. Patient-derived tumor models offer a promising approach by preserving the tumor's integrity, providing a platform for personalized treatment strategies. Zebrafish embryos could be a useful tool for quickly testing potential treatments in parallel. In this research article, we aimed to evaluate the model using a real-world case study and compare results with existing in vitro and in vivo models. A patient-derived cell line from a low-grade serous ovarian cancer with a KRAS mutation was engrafted in zebrafish embryos. Xenografts were assigned to a five-day treatment with trametinib and/or luminespib, targeting two complementary pathways that have previously shown efficacy in other cancer models of this cell line. The zebrafish model offers several options to analyze the response of the tumor to drug exposure. Here, we evaluated both cell growth and cell death, which showed a significant positive tumor response upon treatment that was amplified further by combining the drugs. Ovarian cancer (OC) is an umbrella term for cancerous malignancies affecting the ovaries, yet treatment options for all subtypes are predominantly derived from high-grade serous ovarian cancer, the largest subgroup. The concept of "functional precision medicine" involves gaining personalized insights on therapy choice, based on direct exposure of patient tissues to drugs. This especially holds promise for rare subtypes like low-grade serous ovarian cancer (LGSOC). This study aims to establish an in vivo model for LGSOC using zebrafish embryos, comparing treatment responses previously observed in mouse PDX models, cell lines and 3D tumor models. To address this goal, a well-characterized patient-derived LGSOC cell line with the KRAS mutation c.35 G>T (p.(Gly12Val)) was used. Fluorescently labeled tumor cells were injected into the perivitelline space of 2 days' post-fertilization zebrafish embryos. At 1 day post-injection, xenografts were assessed for tumor size, followed by random allocation into treatment groups with trametinib, luminespib and trametinib + luminespib. Subsequently, xenografts were euthanized and analyzed for apoptosis and proliferation by confocal microscopy. Tumor cells formed compact tumor masses (n = 84) in vivo, with clear Ki67 staining, indicating proliferation. Zebrafish xenografts exhibited sensitivity to trametinib and luminespib, individually or combined, within a two-week period, establishing them as a rapid and complementary tool to existing in vitro and in vivo models for evaluating targeted therapies in LGSOC. [ABSTRACT FROM AUTHOR]

Simple Summary: As the precursor of pepsin, Pepsinogen C (PGC) is the final product of the maturation and differentiation of gastric mucosa cells. The latest bioinformatics analysis found that PGC may play a little-known role in the carcinogenic process, but there is no relevant experimental evidence to prove the effect of PGC on the biological function of cancer cells. In our research, we found PGC may act as a tumor suppressor in the development and metastasis of gastric cancer. PGC can downregulate its interacting protein IQGAP1 and inhibit the Rho-GTPase pathway, thereby participating in the inhibition of gastric cancer cell migration and invasion. Thus, PGC has the potential to be a new therapeutic target for gastric cancer. Aim: This study systematically explored the biological effects and mechanisms of PGC on gastric cancer (GC) cells in vitro and in vivo. Method: The critical biological roles of PGC in GC were assessed via EdU staining, Hoechst staining, flow cytometry, mouse models, CCK-8, wound healing, transwell, and sphere-forming assays. The interaction study with IQ-domain GTPase-activating protein 1 (IQGAP1) was used by Liquid chromatography-mass spectrometry co-immunoprecipitation, immunofluorescence staining, CHX-chase assay, MG132 assay, and qRT-PCR. Results: PGC inhibited the proliferation, viability, epithelial–mesenchymal transition, migration, invasion, and stemness of GC cells and promoted GC cell differentiation. PGC suppressed subcutaneous tumor growth and peritoneal dissemination in vivo. The interaction study found PGC inhibits GC cell migration and invasion by downregulating IQGAP1 protein and IQGAP1-mediated Rho-GTPase signaling suppression. In addition, PGC disrupts the stability of the IQGAP1 protein, promoting its degradation and significantly shortening its half-life. Moreover, the expression levels of PGC and IQGAP1 in GC tissues were significantly negatively correlated. Conclusion: PGC may act as a tumor suppressor in the development and metastasis of GC. PGC can downregulate its interacting protein IQGAP1 and inhibit the Rho-GTPase pathway, thereby participating in the inhibition of GC cell migration and invasion. [ABSTRACT FROM AUTHOR]

Simple Summary: Partial hepatectomy (PH) is a common clinical surgery for managing hepatocellular carcinoma (HCC). A common concern about PH is the high tumor recurrence rate following PH. Previous studies have reported that PH can promote the growth of transplanted HCC in rodents. In the current study, we have used an inducible krasG12V-driven zebrafish HCC model to investigate the effects of PH on the oncogene-induced de novo HCC development. We found that PH can significantly promote the development of krasG12V-induced HCC in zebrafish. This enhancing effect could be attributed to the increased oxidative stress and the enhanced deregulation of molecular factors. Our findings may provide references for the future development of novel therapeutic strategies. The purpose of this study was to investigate the effects of PH on the development of oncogenic krasG12V-induced HCC in zebrafish. The inducible HCC model in Tg(fabp10a:rtTA2s-M2; TRE2:EGFP-krasG12V) zebrafish was used. PH or sham surgery was performed before the induction of oncogenic krasG12V expression in the livers of transgenic zebrafish. Histological analysis was carried out to determine the progression of HCC and other HCC-associated features including hepatocyte proliferation, extracellular matrix production, and local oxidative stress. The similarity between the process of PH-induced liver regeneration and that of krasG12V-induced HCC development was further compared by RNA-Seq analysis. The results show that PH promotes the development of krasG12V-induced HCC in zebrafish possibly through enhancing neutrophil-mediated oxidative stress and promoting the upregulation of s100a1, and the downregulation of ribosome biogenesis. [ABSTRACT FROM AUTHOR]

Simple Summary: Bone cancer-related chronic pain is mediated by central sensitization involving neuroinflammation via glial cell activation in the spinal dorsal horn, but not the capsaicin-sensitive sensory neuronal system. Bone cancer and its related chronic pain are huge clinical problems since the available drugs are often ineffective or cannot be used long term due to a broad range of side effects. The mechanisms, mediators and targets need to be identified to determine potential novel therapies. Here, we characterize a mouse bone cancer model induced by intratibial injection of K7M2 osteosarcoma cells using an integrative approach and investigate the role of capsaicin-sensitive peptidergic sensory nerves. The mechanical pain threshold was assessed by dynamic plantar aesthesiometry, limb loading by dynamic weight bearing, spontaneous pain-related behaviors via observation, knee diameter with a digital caliper, and structural changes by micro-CT and glia cell activation by immunohistochemistry in BALB/c mice of both sexes. Capsaicin-sensitive peptidergic sensory neurons were defunctionalized by systemic pretreatment with a high dose of the transient receptor potential vanilloid 1 (TRPV1) agonist resiniferatoxin (RTX). During the 14- and 28-day experiments, weight bearing on the affected limb and the paw mechanonociceptive thresholds significantly decreased, demonstrating secondary mechanical hyperalgesia. Signs of spontaneous pain and osteoplastic bone remodeling were detected both in male and female mice without any sex differences. Microglia activation was shown by the increased ionized calcium-binding adapter molecule 1 (Iba1) immunopositivity on day 14 and astrocyte activation by the enhanced glial fibrillary acidic protein (GFAP)-positive cell density on day 28 in the ipsilateral spinal dorsal horn. Interestingly, defunctionalization of the capsaicin-sensitive afferents representing approximately 2/3 of the nociceptive fibers did not alter any functional parameters. Here, we provide the first complex functional and morphological characterization of the K7M2 mouse osteosarcoma model. Bone-cancer-related chronic pain and hyperalgesia are likely to be mediated by central sensitization involving neuroinflammation via glial cell activation in the spinal dorsal horn, but not the capsaicin-sensitive sensory neuronal system. [ABSTRACT FROM AUTHOR]

Simple Summary: Cancer genomics and transcriptomics have revealed genes and pathways altered in several cancers. These studies have provided valuable information about cancer cells, their origin, oncogenic processes, and signaling pathways. An emerging challenge is to further characterize activity levels and interactions of pathways to develop a deeper understanding of how specific alterations in these interactions promote tumor growth. Drosophila with its sophisticated genetics has proved valuable in studying cooperative oncogenesis. Using Drosophila tumor models, we report a tumor cell-specific network comprising four pathways. We show that Wingless and effector caspase Dronc direct a signal amplification loop involving JNK and Hippo-effector Yorkie (Yki). Our studies provide evidence from in vivo studies regarding the organization of tumor-promoting oncogenic pathways, which may be useful in developing precise and effective approaches for pathway inhibition. These pathways are evolutionarily conserved from flies to humans, suggesting that findings from flies can be extrapolated to mammalian cancers. Cancer cells expand rapidly in response to altered intercellular and signaling interactions to achieve the hallmarks of cancer. Impaired cell polarity combined with activated oncogenes is known to promote several hallmarks of cancer, e.g., activating invasion by increased activity of Jun N-terminal kinase (JNK) and sustained proliferative signaling by increased activity of Hippo effector Yorkie (Yki). Thus, JNK, Yki, and their downstream transcription factors have emerged as synergistic drivers of tumor growth through pro-tumor signaling and intercellular interactions like cell competition. However, little is known about the signals that converge onto JNK and Yki in tumor cells and enable tumor cells to achieve the hallmarks of cancer. Here, using mosaic models of cooperative oncogenesis (RasV12,scrib−) in Drosophila, we show that RasV12,scrib− tumor cells grow through the activation of a previously unidentified network comprising Wingless (Wg), Dronc, JNK, and Yki. We show that RasV12,scrib− cells show increased Wg, Dronc, JNK, and Yki signaling, and all these signals are required for the growth of RasV12,scrib− tumors. We report that Wg and Dronc converge onto a JNK–Yki self-reinforcing positive feedback signal-amplification loop that promotes tumor growth. We found that the Wg–Dronc–Yki–JNK molecular network is specifically activated in polarity-impaired tumor cells and not in normal cells, in which apical-basal polarity remains intact. Our findings suggest that the identification of molecular networks may provide significant insights into the key biologically meaningful changes in signaling pathways and paradoxical signals that promote tumorigenesis. [ABSTRACT FROM AUTHOR]

Simple Summary: Erastin is a small molecule that was discovered in a screen to selectively kill cancer cells. Mechanistic studies of the cancer cells killed by erastin determined their death to be dependent on iron, increased levels of lipids and oxidative stress. This type of cell death was called "ferroptosis". We hypothesized that even low levels of erastin would lead to changes in signaling pathways in the cell. To test this, we exploited an ex vivo blood–brain barrier transport assay and confirmed our findings in vitro in human tumor cells. We determined that nanomolar levels of erastin could induce specific biological changes in the activity of an important transporter (pump) at the BBB and in tumor cells. We showed that erastin rapidly inhibited the activity of the Multidrug-Resistant Protein (MDR1, P-glycoprotein). Noteworthy, P-glycoprotein is responsible for most of the chemo-resistance in cancer therapies. The blood–brain barrier is composed of both a physical barrier and an enzymatic barrier. Tight junction (TJ) proteins expressed between endothelial cells of brain capillaries provide the physical barrier to paracellular movement of ions and molecules to the brain, while luminal-facing efflux transporters enzymatically restrict the entry of blood-borne molecules from entering the brain. The expression and activity of ATP Binding Cassette transporters or "ABC" transporters in endothelial cells of the BBB and in human tumor cells are dynamically regulated by numerous signaling pathways. P-glycoprotein (P-gp), (ABCB1), is arguably the most studied transporter of the BBB, and in human cell lines. P-glycoprotein transport activity is rapidly inhibited by signaling pathways that call for the rapid production of nitric oxide (NO) from the inducible nitric oxide synthase enzyme, iNOS. This study investigated how nano-molar levels of the selective chemotherapeutic erastin affect the activity or expression of P-glycoprotein transporter in brain capillaries and in human tumor cell lines. We chose erastin because it signals to iNOS for NO production at low concentrations. Furthermore, erastin inhibits the cellular uptake of cystine through the XC− cystine/glutamate antiporter. Since previous reports indicate that NO production from iNOS can rapidly inhibit P-gp activity in tumor cells, we wondered if induction of iNOS by erastin could also rapidly reduce P-glycoprotein transport activity in brain endothelial cells and in human tumor cell lines. We show here that low concentrations of erastin (1 nM) can induce iNOS, inhibit the activity of P-glycoprotein, and reduce the intracellular uptake of cystine via the Xc- cystine/glutamate antiporter. Consistent with reduced P-glycoprotein activity in rat brain capillary endothelial cells, we show that human tumor cell lines exposed to erastin become more sensitive to cytotoxic substrates of P-glycoprotein. [ABSTRACT FROM AUTHOR]

Simple Summary: Acute T-lymphoblastic leukemia is a disease with a very low survival rate after relapse, and the search for new therapeutic agents is important for the clinical benefit of patients with acute T-lymphoblastic leukemia. Our study developed YLS010, a small molecule that is more sensitive to acute T-lymphoblastic leukemia cells, based on the structure of the invented small molecule YLS004. This novel small molecule demonstrated good antitumor activity in vivo and in vitro with acceptable toxicity. These findings provide a new avenue for the development of clinical drugs for patients with acute T-lymphoblastic leukemia. (1) Background: The research group has developed a new small molecule, 6-Isopropyldithio-2′-deoxyguanosine analogs-YLS004, which has been shown to be the most sensitive in acute T-lymphoblastic leukemia cells. Moreover, it was found that the structure of Nelarabine, a drug used to treat acute T-lymphoblastic leukemia, is highly similar to that of YLS004. Consequently, the structure of YLS004 was altered to produce a new small molecule inhibitor for this study, named YLS010. (2) Results: YLS010 has exhibited potent anti-tumor effects by inducing cell apoptosis and ferroptosis. A dose gradient was designed for in vivo experiments based on tentative estimates of the toxicity dose using acute toxicity in mice and long-term toxicity in rats. The study found that YLS010 at a dose of 8 mg/kg prolonged the survival of late-stage acute T-lymphoblastic leukemia mice in the mouse model study. (3) Conclusions: YLS010 has demonstrated specific killing effects against acute T-lymphoblastic leukemia both in vivo and in vitro. Preclinical studies of YLS010 offer a new opportunity for the treatment of patients with acute T-lymphoblastic leukemia in clinical settings. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, a rat model of pancreatic ductal adenocarcinoma (PDAC) was established and extensively analyzed. The histological examination confirmed that the model displayed features of PDAC, such as malformed malignant ductal cells and cancer-associated fibroblasts (CAFs). The study delved into the tumor microenvironment, revealing a unique immune profile with increased CD8+ cytotoxic T cells, suggesting a stronger anti-tumor immune response. Different imaging techniques were employed, showing contrast enhancement on MRI and a strong uptake of 68Ga-FAPI (fibroblast activation protein inhibitor) tracers in tumor tissues. This model's suitability for further research in 68Ga-FAPI imaging and therapeutic approaches was highlighted. While some limitations exist, such as late-stage edema and heterogeneous growth patterns, this model provides valuable insights for PDAC studies and potential therapeutic strategies. The DSL-6A/C1 murine pancreatic ductal adenocarcinoma (PDAC) tumor model was established in Lewis rats and characterized through a comprehensive multiparametric analysis to compare it to other preclinical tumor models and explore potential diagnostic and therapeutical targets. DSL-6A/C1 tumors were histologically analyzed to elucidate PDAC features. The tumor microenvironment was studied for immune cell prevalence. Multiparametric MRI and PET imaging were utilized to characterize tumors, and 68Ga-FAPI-46-targeting cancer-associated fibroblasts (CAFs), were used to validate the histological findings. The histology confirmed typical PDAC characteristics, such as malformed pancreatic ductal malignant cells and CAFs. Distinct immune landscapes were identified, revealing an increased presence of CD8+ T cells and a decreased CD4+ T cell fraction within the tumor microenvironment. PET imaging with 68Ga-FAPI tracers exhibited strong tracer uptake in tumor tissues. The MRI parameters indicated increasing intralesional necrosis over time and elevated contrast media uptake in vital tumor areas. We have demonstrated that the DSL-6A/C1 tumor model, particularly due to its high tumorigenicity, tumor size, and 68Ga-FAPI-46 sensitivity, is a suitable alternative to established small animal models for many forms of preclinical analyses and therapeutic studies of PDAC. [ABSTRACT FROM AUTHOR]

Simple Summary: The metabolism of cancer cells and the tumor microenvironment are of increasing interest as part of ongoing efforts to develop potential adjuvant therapies to be used along with conventional chemotherapy and radiation. In this report, the antitumor properties of two compounds that affect glucose metabolism, dichloroacetate and quercetin, are examined. Both DCA and quercetin, a naturally occurring plant flavonoid found in fruits and vegetables, demonstrate inhibitory effects on the growth of head and neck cancer both in cell culture and in a preclinical mouse model of head and neck cancer. These two compounds have synergistic antitumor effects when combined, both in vitro and in vivo. The drug combination inhibited tumor growth and induced cell death with the maintenance of an unfavorable tumor microenvironment. The altered tumor microenvironment appears to enhance immune-mediated clearance of tumors. Thus, this study supports additional preclinical research to further explore the antitumor effects of DCA and quercetin. Elevated glucose uptake and production of lactate are common features of cancer cells. Among many tumor-promoting effects, lactate inhibits immune responses and is positively correlated with radioresistance. Dichloroacetate (DCA) is an inhibitor of pyruvate dehydrogenase kinase that decreases lactate production. Quercetin is a flavonoid compound found in fruits and vegetables that inhibits glucose uptake and lactate export. We investigated the potential role and mechanisms of DCA, quercetin, and their combination, in the treatment of HPV-positive head and neck squamous cell carcinoma, an antigenic cancer subtype in need of efficacious adjuvant therapies. C57Bl/6-derived mouse oropharyngeal epithelial cells, a previously developed mouse model that was retrovirally transduced with HPV type-16 E6/E7 and activated Ras, were used to assess these compounds. Both DCA and quercetin inhibited colony formation and reduced cell viability, which were associated with mTOR inhibition and increased apoptosis through enhanced ROS production. DCA and quercetin reduced tumor growth and enhanced survival in immune-competent mice, correlating with decreased proliferation as well as decreased acidification of the tumor microenvironment and reduction of Foxp (+) Treg lymphocytes. Collectively, these data support the possible clinical application of DCA and quercetin as adjuvant therapies for head and neck cancer patients. [ABSTRACT FROM AUTHOR]

Simple Summary: Obesity and metabolic syndrome are major drivers of metabolic liver disease and liver cancer. While caloric restriction can abrogate many of the deleterious effects of obesity, weight loss through dieting is not sustainable in the general population. We have investigated whether an alternative approach limiting the window of eating, rather than the caloric content, could have similar beneficial effects. We found that restricting food intake to an eight-hour window during the active phase improved liver metabolism and reduced liver cancer in preclinical models of obesity-driven liver cancer. Metabolic dysfunction-associated steatotic liver disease (MASLD) has surpassed the hepatitis B virus and hepatitis C virus as the leading cause of chronic liver disease in most parts of the Western world. MASLD (formerly known as NAFLD) encompasses both simple steatosis and more aggressive metabolic dysfunction-associated steatohepatitis (MASH), which is accompanied by inflammation, fibrosis, and cirrhosis, and ultimately can lead to hepatocellular carcinoma (HCC). There are currently very few approved therapies for MASH. Weight loss strategies such as caloric restriction can ameliorate the harmful metabolic effect of MASH and inhibit HCC; however, it is difficult to implement and maintain in daily life, especially in individuals diagnosed with HCC. In this study, we tested a time-restricted feeding (TRF) nutritional intervention in mouse models of MASH and HCC. We show that TRF abrogated metabolic dysregulation induced by a Western diet without any calorie restriction or weight loss. TRF improved insulin sensitivity and reduced hyperinsulinemia, liver steatosis, inflammation, and fibrosis. Importantly, TRF inhibited liver tumors in two mouse models of obesity-driven HCC. Our data suggest that TRF is likely to be effective in abrogating MASH and HCC and warrant further studies of time-restricted eating in humans with MASH who are at higher risk of developing HCC. [ABSTRACT FROM AUTHOR]

Simple Summary: Portal hypertension (PH) and hepatocellular carcinoma (HCC) are major complications of liver cirrhosis with a detrimental impact on patient outcomes that share common mechanisms. The incidence of PH in patients with advanced HCC is increasing due to the significant improvement of survival outcomes due to systemic therapies, so the management of the complications associated with clinically significant portal hypertension (such as variceal bleeding and ascites) becomes crucial. Moreover, the administration of systemic treatment presents challenges due to the drug-related bleeding risks. This review aims to elucidate the common pathophysiology of PH and HCC, with a specific focus on the influence of systemic therapies on PH. Moreover, we summarize the available evidence regarding PH management in HCC patients. Finally, we discuss potential new strategies for addressing the coexistence of CSPH and HCC. The management of CSPH in patients undergoing systemic treatment for HCC has emerged as a critical concern due to the absence of reliable diagnostic criteria and uncertainties surrounding therapeutic approaches. This review aims to underscore the primary pathophysiological aspects linking HCC and PH, while also addressing the current and emerging clinical strategies for the management of portal hypertension. A review of studies from January 2003 to June 2023 was conducted using the PubMed database and employing MeSH terms, such as "hepatocellular carcinoma", "immune checkpoint inhibitors", "systemic therapy", "portal hypertension", "variceal bleeding" and "tyrosine kinase inhibitors". Despite promising results of tyrosine kinase inhibitors in animal models for PH and fibrosis, only Sorafenib has demonstrated similar effects in human studies, whereas Lenvatinib appears to promote PH development. The impact of Atezolizumab/Bevacizumab on PH remains uncertain, with an increasing risk of bleeding related to Bevacizumab in patients with prior variceal hemorrhage. Given the absence of specific guidelines, endoscopic surveillance during treatment is advisable, and primary and secondary prophylaxis of variceal bleeding should adhere to the Baveno VII recommendations. Furthermore, in patients with advanced HCC, refinement of diagnostic criteria for CSPH and guidelines for its surveillance are warranted. [ABSTRACT FROM AUTHOR]

Simple Summary: Tamoxifen is prescribed to premenopausal patients with estrogen-receptor-positive breast cancers for a period of 5–10 years after cancer diagnosis. This prolonged treatment regimen, though effective at preventing cancer recurrence, is often associated with unwanted cognitive and affective symptoms. To understand the clinical side effects of tamoxifen, animal studies investigating the effect of tamoxifen on the brain must model the chronic nature of tamoxifen therapy. This study describes a novel method of tamoxifen administration in female rats conducive to long-term administration of tamoxifen. Blood samples from treated rats showed levels of tamoxifen similar to levels in humans. Brain samples revealed tamoxifen-induced changes of a neurotrophic factor in the hippocampus, a structure critical to cognitive and affective processing. This study, therefore, suggests a potential mechanism that may underlie the cognitive side effects reported in patients. Tamoxifen, a selective estrogen receptor modulator (SERM), is commonly used as an adjuvant drug therapy for estrogen-receptor-positive breast cancers. Though effective at reducing the rate of cancer recurrence, patients often report unwanted cognitive and affective side effects. Despite this, the impacts of chronic tamoxifen exposure on the brain are poorly understood, and rodent models of tamoxifen exposure do not replicate the chronic oral administration seen in patients. We, therefore, used long-term ad lib consumption of medicated food pellets to model chronic tamoxifen exposure in a clinically relevant way. Adult female Long-Evans Hooded rats consumed tamoxifen-medicated food pellets for approximately 12 weeks, while control animals received standard chow. At the conclusion of the experiment, blood and brain samples were collected for analyses. Blood tamoxifen levels were measured using a novel ultra-performance liquid chromatography–tandem mass spectrometry assay, which found that this administration paradigm produced serum levels of tamoxifen similar to those in human patients. In the brain, brain-derived neurotrophic factor (BDNF) was visualized in the hippocampus using immunohistochemistry. Chronic oral tamoxifen treatment resulted in a decrease in BDNF expression across several regions of the hippocampus. These findings provide a novel method of modeling and measuring chronic oral tamoxifen exposure and suggest a putative mechanism by which tamoxifen may cause cognitive and behavioral changes reported by patients. [ABSTRACT FROM AUTHOR]

Simple Summary: Cancer stands as the leading cause of death among children and adolescents in the United States. Some of these pediatric cancers are highly aggressive and complex in nature. Current in vitro models often fail to accurately replicate the tumor microenvironment, while in vivo models face time and cost constraints. This review article emphasizes the unique advantages of zebrafish models in pediatric cancer research due to their genetic similarity to humans, short experimental timeline, ease of genetic manipulations, rapid in vivo tumor development, and transparent bodies that facilitate precise tumor cell tracking at single-cell resolution. Through a comprehensive analysis of existing literature and experimental findings, the article highlights the potential of zebrafish as a valuable preclinical model for studying tumor biology, expediting drug discovery and screening processes, and implementing personalized medicine strategies for treating pediatric cancers. Pediatric cancers are the leading cause of disease-related deaths in children and adolescents. Most of these tumors are difficult to treat and have poor overall survival. Concerns have also been raised about drug toxicity and long-term detrimental side effects of therapies. In this review, we discuss the advantages and unique attributes of zebrafish as pediatric cancer models and their importance in targeted drug discovery and toxicity assays. We have also placed a special focus on zebrafish models of pediatric brain cancers—the most common and difficult solid tumor to treat. [ABSTRACT FROM AUTHOR]

Simple Summary: Head and neck cancer is the seventh most common cancer and most cases of head and neck cancer are squamous cell carcinoma (SCC). Recently, immune checkpoint inhibitors (ICPIs) such as anti-programmed cell death-1 (PD-1) have been developed. The aim of our study was to evaluate the antitumor effect of adenoviral vector carrying B7-1 (AdB7) in a murine SCC model in order to further explore the potential of the B7-1 gene in immunotherapy for head and neck cancers. Results indicated that tumor size was significantly reduced in the mice treated with both AdB7 and anti-mouse PD-1 antibody. Additionally, treatment resulted in significantly increased cell densities of total immune cells and Ki-67+ CD8+ T cells and decreased the number of regulatory T cells. Our findings indicate that adenovirus-mediated B7-1 gene expression may enhance the antitumor effect of antiPD1 against SCC. Background: The goal of this study was to evaluate the antitumor immune effects of B7-1 gene expression in addition to immune checkpoint inhibitor against squamous cell carcinoma. Methods: A murine SCC cell line, KLN205, was infected with adenoviral vector carrying B7-1 (AdB7). Infected cells were injected subcutaneously in the flanks of DBA/2 mice. Three weeks after implantation, anti-mouse PD-1 antibody (antiPD1) was intraperitonially administrated twice a week for a total of six times. Results: CD80 was significantly overexpressed in the AdB7-infected tumors. IFN-gamma in the T cells in the spleen was significantly increased and tumor size was significantly reduced in the mice treated with both AdB7 and antiPD1. Targeted tumors treated with both AdB7 and antiPD1 exhibited significantly increased cell densities of total immune cells as well as Ki-67+ CD8+ T cells and decreased regulatory T cells. Conclusions: These results suggest that the B7-1 gene transfer may enhance the antitumor effect of anti-PD1 antibody against SCC. [ABSTRACT FROM AUTHOR]

Simple Summary: Incidence and mortality rates for prostate cancer remain high due to advanced disease characterized by the heterogeneous activation of numerous molecular pathways. In the current study, utilizing a genetic mouse model of advanced prostate cancer with hyperactivated metastasis-associated protein 1/mammalian target of rapamycin (MTA1/mTOR) tumor-promoting pathway, we show for the first time that gnetin C, a natural compound from the melinjo plant, blocks the progression of prostate cancer by reducing cell proliferation and angiogenesis and promoting cell death through the efficient targeting of the MTA1/mTOR pathway. These data may provide a foundation from which to explore gnetin C as a monotherapy and/or combination therapy with approved drugs against advanced prostate cancer in patients with a loss of phosphatase and tensin homolog (PTEN) expression and activated MTA1/mTOR signaling. The metastasis-associated protein 1/protein kinase B (MTA1/AKT) signaling pathway has been shown to cooperate in promoting prostate tumor growth. Targeted interception strategies by plant-based polyphenols, specifically stilbenes, have shown great promise against MTA1-mediated prostate cancer progression. In this study, we employed a prostate-specific transgenic mouse model with MTA1 overexpression on the background of phosphatase and tensin homolog (Pten) null (R26MTA1; Ptenf/f) and PC3M prostate cancer cells which recapitulate altered molecular pathways in advanced prostate cancer. Mechanistically, the MTA1 knockdown or pharmacological inhibition of MTA1 by gnetin C (dimer resveratrol) in cultured PC3M cells resulted in the marked inactivation of mammalian target of rapamycin (mTOR) signaling. In vivo, mice tolerated a daily intraperitoneal treatment of gnetin C (7 mg/kg bw) for 12 weeks without any sign of toxicity. Treatment with gnetin C markedly reduced cell proliferation and angiogenesis and promoted apoptosis in mice with advanced prostate cancer. Further, in addition to decreasing MTA1 levels in prostate epithelial cells, gnetin C significantly reduced mTOR signaling activity in prostate tissues, including the activity of mTOR-target proteins: p70 ribosomal protein S6 kinase (S6K) and eukaryotic translational initiation factor 4E (elF4E)-binding protein 1 (4EBP1). Collectively, these findings established gnetin C as a new natural compound with anticancer properties against MTA1/AKT/mTOR-activated prostate cancer, with potential as monotherapy and as a possible adjunct to clinically approved mTOR pathway inhibitors in the future. [ABSTRACT FROM AUTHOR]

Simple Summary: Breast cancer is the most common cancer in women and one of the deadliest. While survival rates for patients with breast cancer have seen notable improvements in recent decades, current treatment strategies still face significant limitations, especially for patients with aggressive, therapy-resistant, and metastatic breast cancers. For this reason, it is important to identify new targets in order to develop more effective therapeutic strategies. The N-myc downstream regulated gene family (NDRGs), comprising NDRG1, NDRG2, NDRG3, and NDRG4, has been previously described as tumor suppressors. However, recent findings challenge this perception, particularly for NDRG1, which has demonstrated a critical role in driving tumor growth and metastasis in aggressive forms of breast cancer. In this review, we discuss the role of the NDRG family members in breast cancer, which is supported by analyses of genomic and transcriptomic data from various independent breast cancer patient cohorts. The N-myc downstream regulated gene family (NDRGs) includes four members: NDRG1, NDRG2, NDRG3, and NDRG4. These members exhibit 53–65% amino acid identity. The role of NDRGs in tumor growth and metastasis appears to be tumor- and context-dependent. While many studies have reported that these family members have tumor suppressive roles, recent studies have demonstrated that NDRGs, particularly NDRG1 and NDRG2, function as oncogenes, promoting tumor growth and metastasis. Additionally, NDRGs are involved in regulating different signaling pathways and exhibit diverse cellular functions in breast cancers. In this review, we comprehensively outline the oncogenic and tumor suppressor roles of the NDRG family members in breast cancer, examining evidence from in vitro and in vivo breast cancer models as well as tumor tissues from breast cancer patients. We also present analyses of publicly available genomic and transcriptomic data from multiple independent cohorts of breast cancer patients. [ABSTRACT FROM AUTHOR]

Simple Summary: Modern ovarian cancer treatment has not substantially improved outcomes, and superior therapeutic strategies are needed. The aim of this study was to evaluate the efficacy of artesunate and navitoclax drug combination in ovarian cancer. We determined the combination of these two drugs was extraordinarily effective in multiple models of ovarian cancer, in vitro, inhibiting cancer cell proliferation more than expected based on single-agent activities. Unfortunately, we were unable to validate these findings using a mouse model of metastatic ovarian cancer. These data provide valuable information regarding the potential utility and challenges associated with the artesunate/navitoclax drug combination for ovarian cancer therapy. Artesunate belongs to a class of medications derived from the sweet wormwood plant (Artemisia annua) known as artemisinins. Artesunate has traditionally been used as a frontline treatment for severe malaria but has also demonstrated antineoplastic activity against various malignancies, including ovarian cancer. Data suggest that artesunate exacerbates cellular oxidative stress, triggering apoptosis. In the current study, we investigated the ability of navitoclax, an inhibitor of the antiapoptotic Bcl-2 protein family, to enhance artesunate efficacy in ovarian cancer cells. Artesunate and navitoclax both demonstrated antiproliferative effects on 2D and 3D ovarian cancer cell models as single agents. Upon combination of navitoclax with artesunate, antineoplastic drug synergy was also observed in each of the 2D cell lines and ovarian tumor organoid models tested. Further investigation of this drug combination using intraperitoneal CAOV3 xenograft models in BALB/scid mice showed that the artesunate/navitoclax doublet was superior to single-agent artesunate and vehicle control treatment. However, it did not outperform single-agent navitoclax. With optimization, this drug combination could provide a new therapeutic option for ovarian cancer and warrants further preclinical investigation. [ABSTRACT FROM AUTHOR]

Simple Summary: Our in vitro and in vivo experiments demonstrated that bladder tumor growth can be attenuated even with the intravesical administration of lidocaine as a single agent, and that the mechanism involves autophagy influx. These findings support the potential of intravesical lidocaine injection for clinical application. Further successful validation using human-derived bladder cancer cell lines and confirmation of the effectiveness of intravesical lidocaine administration in patients in clinical trials could help establish lidocaine as a novel adjuvant treatment for bladder cancer. Lidocaine exerts potential anti-tumor effects on various cancer cell lines, and its intravesical instillation is considered safer than intravenous administration for bladder cancer. However, the mechanisms underlying its anti-tumor effects have not been fully elucidated. Here, we aimed to elucidate the anti-tumor molecular mechanisms of lidocaine in bladder cancer cells and a xenograft model to substantiate the efficacy of its intravesical administration. We investigated the anti-proliferative and autophagyinducing activities of lidocaine in Nara Bladder Tumor No. 2 (NBT-II) rat bladder carcinoma cells using cell viability, flow cytometry, a wound healing assay, and western blotting. We also established a xenograft mouse model of bladder cancer, and cancer growth was examined using in vivo bioluminescence imaging. Lidocaine decreased cell viability, induced G0/G1 phase cell cycle arrest, and inhibited cell migration partially via glycogen synthase kinase (GSK) 3β phosphorylation. Moreover, a combination of lidocaine and SB216763 (a GSK3β inhibitor) suppressed autophagy-related protein expression. Bafilomycin-A1 with lidocaine significantly enhanced microtubule-associated protein 1A/1B-light chain (LC3B) expression; however, it decreased LC3B expression in combination with 3-methyladenine compared to lidocaine alone. In the xenograft mouse model, the bladder cancer volume was reduced by lidocaine. Overall, lidocaine exerts anti-proliferative effects on bladder cancer via an autophagy-inducing mechanism. [ABSTRACT FROM AUTHOR]

Simple Summary: Breast cancer is a significant global health challenge, ranking as the second leading cause of death worldwide. Current treatment modalities, such as invasive surgery and chemotherapy, while effective to some extent, pose notable risks to patient well-being. High-intensity focused ultrasound (HIFU) offers a non-invasive alternative, utilizing precise acoustic energy for targeted tumor ablation while sparing surrounding healthy tissues. However, HIFU's efficacy depends on various factors, necessitating comprehensive research for optimization. The research focuses on in vitro thermal ablation of epithelial breast cancer cell lines, exploring the impact of HIFU on both 2D monolayer and 3D spheroidal cell configurations. The investigation assesses ultrasound parameters, including acoustic intensity, duty cycle, and sonication duration, evaluating their influence on temperature elevation and tumor cell ablation. Empirical findings are compared with numerical simulations, contributing to a deeper understanding of HIFU's potential in breast cancer treatment and paving the way for more effective therapeutic strategies. High-intensity focused ultrasound (HIFU) is a non-invasive therapeutic modality that uses precise acoustic energy to ablate cancerous tissues through coagulative necrosis. In this context, we investigate the efficacy of HIFU ablation in two distinct cellular configurations, namely 2D monolayers and 3D spheroids of epithelial breast cancer cell lines (MDA-MB 231 and MCF7). The primary objective is to compare the response of these two in vitro models to HIFU while measuring their ablation percentages and temperature elevation levels. HIFU was systematically applied to the cell cultures, varying ultrasound intensity and duty cycle during different sonication sessions. The results indicate that the degree of ablation is highly influenced by the duty cycle, with higher duty cycles resulting in greater ablation percentages, while sonication duration has a minimal impact. Numerical simulations validate experimental observations, highlighting a significant disparity in the response of 2D monolayers and 3D spheroids to HIFU treatment. Specifically, tumor spheroids require lower temperature elevations for effective ablation, and their ablation percentage significantly increases with elevated duty cycles. This study contributes to a comprehensive understanding of acoustic energy conversion within the biological system during HIFU treatment for 2D versus 3D ablation targets, holding potential implications for refining and personalizing breast cancer therapeutic strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: Prostate-specific membrane antigen (PSMA)-targeting radioligands have been used clinically to treat metastatic prostate cancer. To deliver a sufficient radiation dose to eliminate cancer cells, the accumulation of the radioligand in the tumor should be high. Therefore, small-molecular-weight molecules have been modified with albumin binders to enhance their blood circulation time and, hence, increase the tumor uptake. The goal of this study was to investigate the utility of a transthyretin binder (TB-01) to achieve high tumor uptake of the resultant PSMA radioligand. Indeed, the newly developed [177Lu]Lu-PSMA-TB-01 demonstrated enhanced blood circulation as compared to the clinically employed [177Lu]Lu-PSMA-617. Consequently, a significantly higher accumulation of activity was observed in the tumor tissue, while activity retention in off-target tissue was only higher in the kidneys, but otherwise in the same range as for [177Lu]Lu-PSMA-617. Transthyretin binders have previously been used to improve the pharmacokinetic properties of small-molecule drug conjugates and could, thus, be utilized for radiopharmaceuticals as an alternative to the widely explored "albumin binder concept". In this study, a novel PSMA ligand modified with a transthyretin-binding entity (TB-01) was synthesized and labeled with lutetium-177 to obtain [177Lu]Lu-PSMA-TB-01. A high and specific uptake of [177Lu]Lu-PSMA-TB-01 was found in PSMA-positive PC-3 PIP cells (69 ± 3% after 4 h incubation), while uptake in PSMA-negative PC-3 flu cells was negligible (<1%). In vitro binding studies showed a 174-fold stronger affinity of [177Lu]Lu-PSMA-TB-01 to transthyretin than to human serum albumin. Biodistribution studies in PC-3 PIP/flu tumor-bearing mice confirmed the enhanced blood retention of [177Lu]Lu-PSMA-TB-01 (16 ± 1% IA/g at 1 h p.i.), which translated to a high tumor uptake (69 ± 13% IA/g at 4 h p.i.) with only slow wash-out over time (31 ± 8% IA/g at 96 h p.i.), while accumulation in the PC-3 flu tumor and non-targeted normal tissue was reasonably low. Further optimization of the radioligand design would be necessary to fine-tune the biodistribution and enable its use for therapeutic purposes. This study was the first of this kind and could motivate the use of the "transthyretin binder concept" for the development of future radiopharmaceuticals. [ABSTRACT FROM AUTHOR]

Simple Summary: Penile cancer is a rare but aggressive cancer. After it metastasizes, the median survival time is less than 12 months. The overall response rate to common first-line combination chemotherapy treatments is approximately 50%. There is an urgent need in advanced-penile-cancer treatment to find novel therapies that would generate better response rates than standard chemotherapy thus far and have less toxicity. Partially due to its rarity, there are few animal models and cell lines of penile cancer. We report on the generation of seven penile cancer animal models that were created by directly implanting human tumor tissue into immunocompromised mice. Metastatic penile squamous cell carcinoma (PSCC) has only a 50% response rate to first-line combination chemotherapies and there are currently no targeted-therapy approaches. Therefore, we have an urgent need in advanced-PSCC treatment to find novel therapies. Approximately half of all PSCC cases are positive for high-risk human papillomavirus (HR-HPV). Our objective was to generate HPV-positive (HPV+) and HPV-negative (HPV−) patient-derived xenograft (PDX) models and to determine the biological differences between HPV+ and HPV− disease. We generated four HPV+ and three HPV− PSCC PDX animal models by directly implanting resected patient tumor tissue into immunocompromised mice. PDX tumor tissue was found to be similar to patient tumor tissue (donor tissue) by histology and short tandem repeat fingerprinting. DNA mutations were mostly preserved in PDX tissues and similar APOBEC (apolipoprotein B mRNA editing catalytic polypeptide) mutational fractions in donor tissue and PDX tissues were noted. A higher APOBEC mutational fraction was found in HPV+ versus HPV− PDX tissues (p = 0.044), and significant transcriptomic and proteomic expression differences based on HPV status included p16 (CDKN2A), RRM2, and CDC25C. These models will allow for the direct testing of targeted therapies in PSCC and determine their response in correlation to HPV status. [ABSTRACT FROM AUTHOR]

Simple Summary: The prognosis of patients with metastatic colon cancer remains very poor. A minority of patients, mostly those with liver-restricted disease, are eligible for intentionally curative surgery. In most cases, however, the presence of extra-hepatic metastases precludes curative treatment. The aim of this study was to gain insight into the processes governing multi-organ metastasis. We applied the microsurgical transplantation of mouse colon tumor organoids into the caecum or into the liver of syngeneic immunocompetent mice. Colon tumors growing in the liver seeded distant metastases to the lungs and to the peritoneal cavity more efficiently than those growing in the caecum. This was associated with the formation of hotspots of macrophage-surrounded vitronectin-positive blood vessels, specifically in liver tumors. Thus, 'onward spread' from liver metastases plays a major role in multi-organ metastasis, potentially through liver-specific vascular hotspots. The therapeutic targeting of these signals may help achieve the containment of the disease within the liver, thus preventing multi-organ metastasis. Colorectal cancer metastasizes predominantly to the liver but also to the lungs and the peritoneum. The presence of extra-hepatic metastases limits curative (surgical) treatment options and is associated with very poor survival. The mechanisms governing multi-organ metastasis formation are incompletely understood. Here, we tested the hypothesis that the site of tumor growth influences extra-hepatic metastasis formation. To this end, we implanted murine colon cancer organoids into the primary tumor site (i.e., the caecum) and into the primary metastasis site (i.e., the liver) in immunocompetent mice. The organoid-initiated liver tumors were significantly more efficient in seeding distant metastases compared to tumors of the same origin growing in the caecum (intra-hepatic: 51 vs. 40%, p = 0.001; peritoneal cavity: 51% vs. 33%, p = 0.001; lungs: 30% vs. 7%, p = 0.017). The enhanced metastatic capacity of the liver tumors was associated with the formation of 'hotspots' of vitronectin-positive blood vessels surrounded by macrophages. RNA sequencing analysis of clinical samples showed a high expression of vitronectin in liver metastases, along with signatures reflecting hypoxia, angiogenesis, coagulation, and macrophages. We conclude that 'onward spread' from liver metastases is facilitated by liver-specific microenvironmental signals that cause the formation of macrophage-associated vascular hotspots. The therapeutic targeting of these signals may help to contain the disease within the liver and prevent onward spread. [ABSTRACT FROM AUTHOR]

Simple Summary: Cholangiocarcinoma (CCA) accounts for approximately 15% of primary liver cancers. CCA has a poor prognosis and, thus, more effective systemic treatments are needed. We tested opaganib and upamostat, drugs that target sphingosine kinase 2 and multiple serine proteases, primarily trypsins, which are highly expressed in CCA tumors. This study demonstrates the results of inhibiting these novel targets with these drugs individually and in combination in a patient-derived CCA xenograft mouse model. Upamostat is an orally available small-molecule serine protease inhibitor that is a highly potent inhibitor of trypsin 1, trypsin 2, trypsin 3 (PRSS1/2/3), and the urokinase-type plasminogen activator (uPA). These enzymes are expressed in many cancers, especially during tissue remodeling and subsequent tumor cell invasion. Opaganib (ABC294640), a novel, orally available small molecule is a selective inhibitor of the phosphorylation of sphingosine to sphingosine-1-phosphate (S-1-P) by sphingosine kinase 2 (SPHK2). Both sphingosine kinase 1 (SPHK1) and SPHK2 are known to regulate the proliferation-inducing compound S-1-P. However, SPHK2 is more critical in cancer pathogenesis. The goal of this project was to investigate the potential antitumor effects of upamostat and opaganib, individually and in combination, on cholangiocarcinoma (CCA) xenografts in nude mice. PAX165, a patient-derived xenograft (PDX) from a surgically resected CCA, expresses substantial levels of SPHK2, PRSS1, PRSS2, and PRSS3. Four groups of 18 mice each were treated with upamostat, opaganib, both, or vehicle. Mouse weights and PAX165 tumor volumes were measured. Tumor volumes in the upamostat, opaganib, and upamostat plus opaganib groups were significantly decreased compared to the control group. [ABSTRACT FROM AUTHOR]

Simple Summary: Glioblastoma multiforme (GBM) ranks as the most frequent form of primary malignant brain tumor. The prognosis for individuals diagnosed with this disease typically leads to a median survival of under two years. Here, we developed mouse models to better understand the genetic basis of GBM, a highly aggressive brain tumor. We found that certain genetic alterations, such as Kirsten rat sarcoma viral oncogene homologue (KRAS) activation and p53 deficiency, cooperate to initiate glioma tumorigenesis. Combining these alterations with adenomatous polyposis coli (APC) haploinsufficiency led to the rapid progression of GBM in the mice, resembling the human disease. These models are valuable for identifying early disease biomarkers and may offer insights for improving the diagnosis and treatment of this challenging brain tumor. Glioblastoma multiforme (GBM) is the most common and deadly type of brain tumor originating from glial cells. Despite decades of clinical trials and research, there has been limited success in improving survival rates. However, molecular pathology studies have provided a detailed understanding of the genetic alterations associated with the formation and progression of glioblastoma—such as Kirsten rat sarcoma viral oncogene homolog (KRAS) signaling activation (5%), P53 mutations (25%), and adenomatous polyposis coli (APC) alterations (2%)—laying the groundwork for further investigation into the biological and biochemical basis of this malignancy. These analyses have been crucial in revealing the sequential appearance of specific genetic lesions at distinct histopathological stages during the development of GBM. To further explore the pathogenesis and progression of glioblastoma, here, we developed the glial-fibrillary-acidic-protein (GFAP)-Cre-driven mouse model and demonstrated that activated KRAS and p53 deficiencies play distinct and cooperative roles in initiating glioma tumorigenesis. Additionally, the combination of APC haploinsufficiency with mutant Kras activation and p53 deletion resulted in the rapid progression of GBM, characterized by perivascular inflammation, large necrotic areas, and multinucleated giant cells. Consequently, our GBM models have proven to be invaluable resources for identifying early disease biomarkers in glioblastoma, as they closely mimic the human disease. The insights gained from these models may pave the way for potential advancements in the diagnosis and treatment of this challenging brain tumor. [ABSTRACT FROM AUTHOR]

Simple Summary: The success of cancer immunotherapy is largely associated with immunologically hot tumors. Oncolytic viruses can transform cold tumors into hot tumors. In this study, we found that an oncolytic vaccinia virus (oVV) expressing interleukin-9 (IL-9) can transform cold tumors into hot tumors and that it elicited effective antitumor effects. The antitumor effects can be enhanced in combination with an immune checkpoint blockade, indicating a potential translation of the IL-9-expressing oncolytic virus into a clinical trial to enhance the antitumor effects elicited by immune checkpoint blockades for cancer immunotherapy. The success of cancer immunotherapy is largely associated with immunologically hot tumors. Approaches that promote the infiltration of immune cells into tumor beds are urgently needed to transform cold tumors into hot tumors. Oncolytic viruses can transform the tumor microenvironment (TME), resulting in immunologically hot tumors. Cytokines are good candidates for arming oncolytic viruses to enhance their function in this transformation. Here, we used the oncolytic vaccinia virus (oVV) to deliver interleukin-9 (IL-9) into the tumor bed and explored its antitumor effects in colon and lung tumor models. Our data show that IL-9 prolongs viral persistence, which is probably mediated by the up-regulation of IL-10. The vvDD-IL-9 treatment elevated the expression of Th1 chemokines and antitumor factors such as IFN-γ, granzyme B, and perforin. IL-9 expression increased the percentages of CD4+ and CD8+ T cells in the TME and decreased the percentage of oVV-induced immune suppressive myeloid-derived suppressor cells (MDSC), leading to potent antitumor effects compared with parental virus treatment. The vvDD-IL-9 treatment also increased the percentage of regulatory T cells (Tregs) in the TME and elevated the expression of immune checkpoint molecules such as PD-1, PD-L1, and CTLA-4, but not GITR. The combination therapy of vvDD-IL-9 and the anti-CTLA-4 antibody, but not the anti-GITR antibody, induced systemic tumor-specific antitumor immunity and significantly extended the overall survival of mice, indicating a potential translation of the IL-9-expressing oncolytic virus into a clinical trial to enhance the antitumor effects elicited by an immune checkpoint blockade for cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Melanoma is an immunogenic tumor, so its outcomes and the efficacy of immunotherapy must be linked to the immune component. In this study, we aimed to find indicators that would allow us to monitor both the prognosis of patients and the efficacy of immunotherapy. We found that complement C2 tended to be upregulated in patients after effective anti-PD-1 therapy, and the high expression group achieved longer survival. Tumor tissues with C2 expression were infiltrated with more M1-type macrophages and tertiary lymphoid structures, and this favorable immune status may be responsible for the favorable outcome. Our findings provide valuable insights into the functional role of C2 in melanoma and its potential implications for clinical therapy. Immunotherapy is an essential therapy for individuals with advanced melanoma. However, not all patients respond to such treatment due to individual differences. We conducted a multidimensional analysis using transcriptome data from our center, as well as publicly available databases. We found that effective nivolumab treatment led to an upregulation of C2 levels, and higher levels following treatment are indicative of a good outcome. Through bioinformatics analyses and immunofluorescence, we identified a correlation between C2 and M1 macrophages. To further investigate the role of C2 in melanoma, we constructed subcutaneous tumorigenic models in C57BL/6 mice. The tumors in the C2 overexpression group exhibited significantly smaller sizes. Flow cytometric analysis of the mouse tumors demonstrated enhanced recruitment of macrophages, particularly of the M1 subtype, in the overexpression group. Moreover, single-cell RNA sequencing analysis revealed that C2-positive tumor cells exhibited enhanced communication with immune cells. We co-cultured tumor cell supernatants with macrophages in vitro and observed the induction of M1 subtype polarization. In addition, we discovered a close correlation between C2 and tertiary lymphoid structures. C2 has been demonstrated to exert a protective effect, mediated by its ability to modulate the tumor microenvironment. C2 serves as a prognostic marker for melanoma and can be employed to monitor the efficacy of immunotherapy. [ABSTRACT FROM AUTHOR]

Simple Summary: New treatments have made a big difference in helping people with multiple myeloma (MM) live longer. In fact, survival rates have almost doubled compared with treatments before 2000, thanks to these new and effective medications. This means more people with MM are surviving for more than 10 years after being diagnosed. However, because people are living longer, some unusual situations are arising, like cancer coming back in places outside the bone marrow, such as organs, lymph nodes, and even the central nervous system. To better understand and treat these new challenges, scientists are using advanced 3D models, especially looking at the bone marrow and other places where cancer may show up. This review identifies the best ways to use these 3D models, discusses the difficulties in recreating the complexity of the disease, and emphasizes how these advanced models can help fight MM. Recent therapeutic advancements have markedly increased the survival rates of individuals with multiple myeloma (MM), doubling survival compared to pre-2000 estimates. This progress, driven by highly effective novel agents, suggests a growing population of MM survivors exceeding the 10-year mark post-diagnosis. However, contemporary clinical observations indicate potential trends toward more aggressive relapse phenotypes, characterized by extramedullary disease and dominant proliferative clones, despite these highly effective treatments. To build upon these advances, it is crucial to develop models of MM evolution, particularly focusing on understanding the biological mechanisms behind its development outside the bone marrow. This comprehensive understanding is essential to devising innovative treatment strategies. This review emphasizes the role of 3D models, specifically addressing the bone marrow microenvironment and development of extramedullary sites. It explores the current state-of-the-art in MM modelling, highlighting challenges in replicating the disease's complexity. Recognizing the unique demand for accurate models, the discussion underscores the potential impact of these advanced 3D models on understanding and combating this heterogeneous and still incurable disease. [ABSTRACT FROM AUTHOR]

Simple Summary: The objective of drug repurposing is to discover novel therapeutic uses for established pharmaceuticals. Paroxetine (PX), a commonly prescribed antidepressant, has demonstrated promising anticancer properties in experimental studies. Nevertheless, its precise role and mechanisms of action in triple-negative breast cancer (TNBC) remain incompletely elucidated. Our research findings propose that PX may impact TNBC by modulating critical molecular pathways, providing significant implications for enhancing chemosensitivity and identifying potential therapeutic synergies in clinical practice. These findings provide a basis for the creation of individualized treatment plans and the identification of the most effective therapeutic interventions to enhance treatment precision and effectiveness in patients with TNBC. The strategy of drug repurposing has gained traction in the field of cancer therapy as a means of discovering novel therapeutic uses for established pharmaceuticals. Paroxetine (PX), a selective serotonin reuptake inhibitor typically utilized in the treatment of depression, has demonstrated promise as an agent for combating cancer. Nevertheless, the specific functions and mechanisms by which PX operates in the context of triple-negative breast cancer (TNBC) remain ambiguous. This study aimed to examine the impact of PX on TNBC cells in vitro as both a standalone treatment and in conjunction with other pharmaceutical agents. Cell viability was measured using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, apoptosis was assessed through flow cytometry, and the effects on signaling pathways were analyzed using RNA sequencing and Western blot techniques. Furthermore, a subcutaneous tumor model was utilized to assess the in vivo efficacy of combination therapy on tumor growth. The results of our study suggest that PX may activate the Ca2+-dependent mitochondria-mediated intrinsic apoptosis pathway in TNBC by potentially influencing the PI3K/AKT/mTOR pathway as well as by inducing cytoprotective autophagy. Additionally, the combination of PX and chemotherapeutic agents demonstrated moderate inhibitory effects on 4T1 tumor growth in an in vivo model. These findings indicate that PX may exert its effects on TNBC through modulation of critical molecular pathways, offering important implications for improving chemosensitivity and identifying potential therapeutic combinations for clinical use. [ABSTRACT FROM AUTHOR]

Simple Summary: The mesenchymal (MES) phenotype of glioblastoma (GBM) confers resistance to various therapeutic strategies and results from both tumor-intrinsic genetic alterations and tumor-extrinsic microenvironmental factors. In this study, we sought to identify and validate the key genes that regulate the MES phenotype of glioma via both mechanisms. By integrating bulk tumor data (using the TCGA and CGGA databases) and single-cell sequencing data of GBM, we revealed that the plasminogen activator, urokinase receptor (PLAUR) is the hub gene of the protumor microenvironment, encompassing hypoxia and immunosuppression, and we elucidated its role in driving the MES transition through both tumor-intrinsic function and cell-to-cell interaction. Our findings indicate that PLAUR may be a potential target for GBM treatment, as our research elucidated its functions through a comprehensive study. The mesenchymal (MES) phenotype of glioblastoma (GBM) is the most aggressive and therapy-resistant subtype of GBM. The MES phenotype transition during tumor progression results from both tumor-intrinsic genetic alterations and tumor-extrinsic microenvironmental factors. In this study, we sought to identify genes that can modulate the MES phenotype via both mechanisms. By integrating weighted gene co-expression network analysis (WGCNA) and the differential expression analysis of hypoxia-immunosuppression-related genes, we identified the plasminogen activator, urokinase receptor (PLAUR) as the hub gene. Functional enrichment analysis and GSVA analysis demonstrated that PLAUR was associated with the MES phenotype of glioma and the hypoxia-immunosuppression-related microenvironmental components. Single-cell sequencing analysis revealed that PLAUR mediated the ligand–receptor interaction between tumor-associated macrophages (TAMs) and glioma cells. Functional experiments in vitro with cell lines or primary glioma cells and xenograft models using BALB/c nude mice confirmed the role of PLAUR in promoting the MES phenotype of GBM. Our findings indicate that PLAUR regulates both glioma cells and tumor cell-extrinsic factors that favor the MES phenotype and suggest that PLAUR might be a potential target for GBM therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Sonodynamic therapy (SDT) is emerging as a promising innovative technique for treating malignant gliomas in a noninvasive fashion. The use of fluorescein, instead of 5-aminolevulinic acid, could extend the application of sonodynamic therapy to intracranial tumors other than gliomas. Our aim was to investigate the feasibility of sonodynamic therapy with fluorescein in an intracranial mouse model of malignant glioma, its efficacy, and its effects on the immune microenvironment. Fluorescein-mediated sonodynamic therapy (FL-SDT) is an extremely promising approach for glioma treatment, resulting from the combination of low-intensity focused ultrasound (FUS) with a sonosensitizer. In the present study, we evaluated the efficacy and immunomodulation of SDT with fluorescein as the sonosensitizer in immunocompetent GL261 glioma mice for the first time. In vitro studies demonstrated that the exposure of GL261 cells to FL-SDT induced immunogenic cell death and relevant upregulation of MHC class I, CD80 and CD86 expression. In vivo studies were then performed to treat GL261 glioma-bearing mice with FL-SDT, fluorescein alone, or FUS alone. Perturbation of the glioma-associated macrophage subset within the immune microenvironment was induced by all the treatments. Notably, a relevant depletion of myeloid-derived suppressor cells (MDSCs) and concomitant robust infiltration of CD8+ T cells were observed in the SDT-FL-treated mice, resulting in a significant radiological delay in glioma progression and a consequent improvement in survival. Tumor control and improved survival were also observed in mice treated with FL alone (median survival 41.5 days, p > 0.0001 compared to untreated mice), reflecting considerable modulation of the immune microenvironment. Interestingly, a high circulating lymphocyte-to-monocyte ratio and a very low proportion of MDSCs were predictive of better survival in FL- and FL-SDT-treated mice than in untreated and FUS-treated mice, in which elevated monocyte and MDSC frequencies correlated with worse survival. The immunostimulatory potential of FL-SDT treatment and the profound modulation of most immunosuppressive components within the microenvironment encouraged the exploration of the combination of FL-SDT with immunotherapeutic strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: We introduced a drug screening platform for patient-derived cells (PDCs) from lung cancer patients. The drug sensitivity results of short-term-cultured PDCs were significantly associated with clinical outcomes in patients with targeted therapy. The PDC drug screening platform was useful to predict the clinical outcomes of patients treated with targeted therapy and facilitated precision medicine for patients without relevant driver oncogenes. We expect that the PDC drug screening platform, as a feasible tool, can be used to guide target therapy for lung cancer patients and may overcome the limitation of genomic assay-based targeted therapy. Intratumor heterogeneity leads to different responses to targeted therapies, even within patients whose tumors harbor identical driver oncogenes. This study examined clinical outcomes according to a patient-derived cell (PDC)-based drug sensitivity test in lung cancer patients treated with targeted therapies. From 487 lung cancers, 397 PDCs were established with a success rate of 82%. In 139 PDCs from advanced non-small-cell lung cancer (NSCLC) patients receiving targeted therapies, the standardized area under the curve (AUC) values for the drugs was significantly correlated with their tumor response (p = 0.002). Among 59 chemo-naive EGFR/ALK-positive NSCLC patients, the PDC non-responders showed a significantly inferior response rate (RR) and progression-free survival (PFS) for the targeted drugs than the PDC responders (RR, 25% vs. 78%, p = 0.011; median PFS, 3.4 months [95% confidence interval (CI), 2.8–4.1] vs. 11.8 months [95% CI, 6.5–17.0], p < 0.001). Of 25 EGFR-positive NSCLC patients re-challenged with EGFR inhibitors, the PDC responder showed a higher RR than the PDC non-responder (42% vs. 15%). Four patients with wild-type EGFR or uncommon EGFR-mutant NSCLC were treated with EGFR inhibitors based on their favorable PDC response to EGFR inhibitors, and two patients showed dramatic responses. Therefore, the PDC-based drug sensitivity test results were significantly associated with clinical outcomes in patients with EGFR- or ALK-positive NSCLC. It may be helpful for predicting individual heterogenous clinical outcomes beyond genomic alterations. [ABSTRACT FROM AUTHOR]

Simple Summary: Cells with stem-like potential in head and neck squamous cell carcinoma (HNSCC) have been shown to exhibit features of intrinsic resistance to ionizing radiation. These cells, often referred to as cancer stem cells (CSCs), are characterized by an increased self-renewal and clonogenic potential, features associated with epithelial-to-mesenchymal transition (EMT), migratory behavior, and cellular plasticity. Cellular plasticity entails changes in phenotype and function in response to therapeutic pressures such as irradiation. Previously, we found that ALDH-positive CSCs are enriched in HNSCC cultures upon treatment with ionizing radiation. This process was characterized by mechanisms involving a selection of resistant populations and an induction of stem-like features. Cellular plasticity is regulated intracellularly through epigenetic mechanisms, including dynamic adaptations of DNA methylation and histone methylation, resulting in gene-specific alterations of expression levels. Therefore, we hypothesized that epigenetic targeting may prevent irradiation-induced cellular plasticity, rendering resistant HNSCC cells more sensitive. Employing a chemical library screen, we identified the histone demethylase inhibitor GSK-J1 to have a putative radiosensitizing effect that also reduces the stem-like potential of these cells. (1) Background: The sensitivity of head and neck squamous cell carcinoma (HNSCC) to ionizing radiation, among others, is determined by the number of cells with high clonogenic potential and stem-like features. These cellular characteristics are dynamically regulated in response to treatment and may lead to an enrichment of radioresistant cells with a cancer stem cell (CSC) phenotype. Epigenetic mechanisms, particularly DNA and histone methylation, are key regulators of gene-specific transcription and cellular plasticity. Therefore, we hypothesized that specific epigenetic targeting may prevent irradiation-induced plasticity and may sensitize HNSCC cells to radiotherapy. (2) Methods: We compared the DNA methylome and intracellular concentrations of tricarboxylic acid cycle metabolites in radioresistant FaDu and Cal33 cell lines with their parental controls, as well as aldehyde dehydrogenase (ALDH)-positive CSCs with negative controls. Moreover, we conducted a screen of a chemical library targeting enzymes involved in epigenetic regulation in combination with irradiation and analyzed the clonogenic potential, sphere formation, and DNA repair capacity to identify compounds with both radiosensitizing and CSC-targeting potential. (3) Results: We identified the histone demethylase inhibitor GSK-J1, which targets UTX (KDM6A) and JMJD3 (KDM6B), leading to increased H3K27 trimethylation, heterochromatin formation, and gene silencing. The clonogenic survival assay after siRNA-mediated knock-down of both genes radiosensitized Cal33 and SAS cell lines. Moreover, high KDM6A expression in tissue sections of patients with HNSCC was associated with improved locoregional control after primary (n = 137) and post-operative (n = 187) radio/chemotherapy. Conversely, high KDM6B expression was a prognostic factor for reduced overall survival. (4) Conclusions: Within this study, we investigated cellular and molecular mechanisms underlying irradiation-induced cellular plasticity, a key inducer of radioresistance, with a focus on epigenetic alterations. We identified UTX (KDM6A) as a putative prognostic and therapeutic target for HNSCC patients treated with radiotherapy. [ABSTRACT FROM AUTHOR]

Simple Summary: Prolactinoma is the most common subtype and composes about 40–66% of all pituitary neuroendocrine tumors (PitNETs). Studies suggested that some other subtypes of PitNETs, such as Acromegaly and Cushing disease, could result in hypertension. However, this relationship remains unclear in prolactinoma. Our study revealed that in situ rat and xenograft nude-mice prolactinoma induced a significant BP increase, which was attenuated by cabergoline (CAB) treatment. In clinic, surgery decreased BP in prolactinoma patients both with or without hypertension. This BP-lowering effect was significantly associated with several variables, including age, sex, disease duration, tumor size, invasion, resistance to dopamine agonists (DAs), recurrence, and preoperative PRL levels. Several subtypes of pituitary neuroendocrine tumors (PitNETs), such as acromegaly and Cushing's disease, can result in hypertension. However, whether prolactinoma is associated with this complication remains unknown. Moreover, the effect of treatment with surgery or drugs on blood pressure (BP) is unknown. Herein, a retrospective study reviewed 162 patients with prolactinoma who underwent transsphenoidal surgery between January 2005 and December 2022. BP measurements were performed 1 day before and 5 days after surgery. Accordingly, patients' medical characteristics were recorded. In addition, in situ rat and xenograft nude-mice prolactinoma models have been used to mimic prolactinoma. In vivo BP and serum prolactin (PRL) levels were measured after cabergoline (CAB) administration in both rats and mice. Our data suggest that surgery can effectively decrease BP in prolactinoma patients with or without hypertension. The BP-lowering effect was significantly associated with several variables, including age, sex, disease duration, tumor size, invasion, dopamine agonists (DAs)-resistance, recurrence, and preoperative PRL levels. Moreover, in situ and xenograft prolactinomas induced BP elevation, which was alleviated by CAB treatment without and with a statistical difference in rats and mice, respectively. Thus, surgery or CAB can decrease BP in prolactinoma, indicating that pre- and postoperative BP management becomes essential. [ABSTRACT FROM AUTHOR]

Simple Summary: We aimed to investigate the intrinsic biomechanical properties of melanoma cancer cells. We demonstrate that the modulation of stiffness properties, and their correlated morphometrics, impacts cutaneous melanoma cell invasiveness following EMT switching and Tspan8 transcriptional activation. Thus, we propose that melanoma stiffness measurement could be of prognostic relevance for patients. The intrinsic biomechanical properties of cancer cells remain poorly understood. To decipher whether cell stiffness modulation could increase melanoma cells' invasive capacity, we performed both in vitro and in vivo experiments exploring cell stiffness by atomic force microscopy (AFM). We correlated stiffness properties with cell morphology adaptation and the molecular mechanisms underlying epithelial-to-mesenchymal (EMT)-like phenotype switching. We found that melanoma cell stiffness reduction was systematically associated with the acquisition of invasive properties in cutaneous melanoma cell lines, human skin reconstructs, and Medaka fish developing spontaneous MAP-kinase-induced melanomas. We observed a systematic correlation of stiffness modulation with cell morphological changes towards mesenchymal characteristic gains. We accordingly found that inducing melanoma EMT switching by overexpressing the ZEB1 transcription factor, a major regulator of melanoma cell plasticity, was sufficient to decrease cell stiffness and transcriptionally induce tetraspanin-8-mediated dermal invasion. Moreover, ZEB1 expression correlated with Tspan8 expression in patient melanoma lesions. Our data suggest that intrinsic cell stiffness could be a highly relevant marker for human cutaneous melanoma development. [ABSTRACT FROM AUTHOR]

Simple Summary: c-FLIP is a master anti-apoptotic regulator associated with resistance to various therapeutic options in different cancer types. Thus, exploring the combinatorial antitumor effects of a natural product, physachenolide C (PCC) and bortezomib, could lead to an effective, non-toxic therapeutic regimen against KRASmut/P53mut lung cancer cells. Our results showed that the bortezomib–PCC combination was more effective in reducing the viability and inhibiting migration and invasion of cancer cells. Additionally, c-FLIP protein expression was significantly inhibited along with a substantial reduction in the critical parameters of cellular metabolism in cancer cells. Strikingly, tumor growth inhibition was much more effective in tumor xenograft mice models with an enhanced efficacy without causing significant side effects. Background: Defects in apoptosis regulation are one of the classical features of cancer cells, often associated with more aggressiveness and failure to therapeutic options. We investigated the combinatorial antitumor effects of a natural product, physachenolide C (PCC) and bortezomib, in KRASmut/P53mut lung cancer cells and xenograft mice models. Methods: The in vitro anticancer effects of the bortezomib and PCC combination were investigated using cell viability, migration, and invasion assays in 344SQ, H23, and H358 cell lines. Furthermore, the effects of combination treatment on the critical parameters of cellular metabolism, including extracellular acidification rate (ECAR) and mitochondrial oxidative phosphorylation based on the oxygen consumption rate of cancer cells were assessed using Seahorse assay. Finally, the antitumor effect of the bortezomib (1 mg/kg) and PCC (10 mg/kg) combination was evaluated using xenograft mice models. Results: Our data showed that the bortezomib–PCC combination was more effective in reducing the viability of lung cancer cells in comparison with the individual treatments. Similarly, the combination treatment showed a significant inhibition of cell migration and invasion of cancer cells. Additionally, the key anti-apoptotic protein c-FLIP was significantly inhibited along with a substantial reduction in the key parameters of cellular metabolism in cancer cells. Notably, the bortezomib or PCC inhibited the tumor growth compared to the control group, the tumor growth inhibition was much more effective when bortezomib was combined with PCC in tumor xenograft mice models. Conclusion: These findings demonstrate that PCC sensitizes cancer cells to bortezomib, potentially improving the antitumor effects against KRASmut/P53mut lung cancer cells, with an enhanced efficacy of combination treatments without causing significant side effects. [ABSTRACT FROM AUTHOR]

Simple Summary: We discovered a novel association of cancer and stemness. In particular, we demonstrate an MACC1—LGR5 link by transcriptional regulation of the crucial stemness gene LGR5 by MACC1, the inducer of tumor initiation, progression and metastasis. We show this regulation by using 2D and 3D cell culture models, in CRC-derived PDX mouse models and in human CRC patient samples. This study indicates that the metastasis inducer MACC1 acts not only as a cancer stem cell-associated marker, but also as a regulator of LGR5 expression and LGR5-mediated stem cell properties. Thus, interventional approaches targeting MACC1 would potentially improve further targeted therapies for CRC patients to eradicate CSCs and prevent cancer recurrence and distant metastasis formation. Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. The high mortality is directly associated with metastatic disease, which is thought to be initiated by colon cancer stem cells, according to the cancer stem cell (CSC) model. Consequently, early identification of those patients who are at high risk for metastasis is crucial for improved treatment and patient outcomes. Metastasis-associated in colon cancer 1 (MACC1) is a novel prognostic biomarker for tumor progression and metastasis formation independent of tumor stage. We previously showed an involvement of MACC1 in cancer stemness in the mouse intestine of our MACC1 transgenic mouse models. However, the expression of MACC1 in human CSCs and possible implications remain elusive. Here, we explored the molecular mechanisms by which MACC1 regulates stemness and the CSC-associated invasive phenotype based on patient-derived tumor organoids (PDOs), patient-derived xenografts (PDXs) and human CRC cell lines. We showed that CD44-enriched CSCs from PDO models express significantly higher levels of MACC1 and LGR5 and display higher tumorigenicity in immunocompromised mice. Similarly, RNA sequencing performed on PDO and PDX models demonstrated significantly increased MACC1 expression in ALDH1(+) CSCs, highlighting its involvement in cancer stemness. We further showed the correlation of MACC1 with the CSC markers CD44, NANOG and LGR5 in PDO models as well as established cell lines. Additionally, MACC1 increased stem cell gene expression, clonogenicity and sphere formation. Strikingly, we showed that MACC1 binds as a transcription factor to the LGR5 gene promoter, uncovering the long-known CSC marker LGR5 as a novel essential signaling mediator employed by MACC1 to induce CSC-like properties in human CRC patients. Our in vitro findings were further substantiated by a significant positive correlation of MACC1 with LGR5 in CRC cell lines as well as CRC patient tumors. Taken together, this study indicates that the metastasis inducer MACC1 acts as a cancer stem cell-associated marker. Interventional approaches targeting MACC1 would potentially improve further targeted therapies for colorectal cancer patients to eradicate CSCs and prevent cancer recurrence and distant metastasis formation. [ABSTRACT FROM AUTHOR]

Simple Summary: Microbeam radiation therapy (MRT) is a novel, still pre-clinical form of radiation therapy for cancer treatment, where the dose is applied in spatial fractions. MRT was shown to be able to treat tumors effectively while causing reduced damage to normal tissue. Research on MRT nowadays requires large, expensive, and difficult-to-access facilities. In this study, we aim to develop an easily accessible MRT setup utilizing a conventional small animal irradiator. We developed a comprehensive treatment planning system with a dose calculation accuracy of 10%. We successfully applied microbeam radiation to a mouse in vivo and showed that the microbeam pattern is preserved by analyzing histological sections of a mouse brain. We demonstrated the feasibility of MRT using our developed setup. Microbeam radiation therapy (MRT) is a still pre-clinical form of spatially fractionated radiotherapy, which uses an array of micrometer-wide, planar beams of X-ray radiation. The dose modulation in MRT has proven effective in the treatment of tumors while being well tolerated by normal tissue. Research on understanding the underlying biological mechanisms mostly requires large third-generation synchrotrons. In this study, we aimed to develop a preclinical treatment environment that would allow MRT independent of synchrotrons. We built a compact microbeam setup for pre-clinical experiments within a small animal irradiator and present in vivo MRT application, including treatment planning, dosimetry, and animal positioning. The brain of an immobilized mouse was treated with MRT, excised, and immunohistochemically stained against γ H2AX for DNA double-strand breaks. We developed a comprehensive treatment planning system by adjusting an existing dose calculation algorithm to our setup and attaching it to the open-source software 3D-Slicer. Predicted doses in treatment planning agreed within 10% with film dosimetry readings. We demonstrated the feasibility of MRT exposures in vivo at a compact source and showed that the microbeam pattern is observable in histological sections of a mouse brain. The platform developed in this study will be used for pre-clinical research of MRT. [ABSTRACT FROM AUTHOR]

Simple Summary: Acute myeloid leukemia (AML) is the abnormal growth of immature blood cells characterized by a block in differentiation. The therapy options to treat AML have primarily consisted of cytotoxic chemotherapy, until more recently, when small-molecule targeted therapy emerged. Many of these targeted therapies are directed at agents that can cause abnormal cells to differentiate. Herein, we discuss the role of a small molecule inhibitor of enhancer of zeste homolog 2 (EZH2), which can induce differentiation and promote survival in AML models. Background: Acute myeloid leukemia (AML) is the malignant proliferation of immature myeloid cells characterized by a block in differentiation. As such, novel therapeutic strategies to promote the differentiation of immature myeloid cells have been successful in AML, although these agents are targeted to a specific mutation that is only present in a subset of AML patients. In the current study, we show that targeting the epigenetic modifier enhancer of zeste homolog 2 (EZH2) can induce the differentiation of immature blast cells into a more mature myeloid phenotype and promote survival in AML murine models. Methods: The EZH2 inhibitor EPZ011989 (EPZ) was studied in AML cell lines, primary in AML cells and normal CD34+ stem cells. A pharmacodynamic assessment of H3K27me3; studies of differentiation, cell growth, and colony formation; and in vivo therapeutic studies including the influence on primary AML cell engraftment were also conducted. Results: EPZ inhibited H3K27me3 in AML cell lines and primary AML samples in vitro. EZH2 inhibition reduced colony formation in multiple AML cell lines and primary AML samples, while exhibiting no effect on colony formation in normal CD34+ stem cells. In AML cells, EPZ promoted phenotypic evidence of differentiation. Finally, the pretreatment of primary AML cells with EPZ significantly delayed engraftment and prolonged the overall survival when engrafted into immunodeficient mice. Conclusions: Despite evidence that EZH2 silencing in MDS/MPN can promote AML pathogenesis, our data demonstrate that the therapeutic inhibition of EZH2 in established AML has the potential to improve survival. [ABSTRACT FROM AUTHOR]

Simple Summary: Over the last two decades, there has been a major shift in cancer research models. What was once dominated by genetically engineered mice models and fast-growing immortalized cancer cell lines has given way to a number of patient-derived models of cancer (PDMCs) that may be more representative of human disease. However, the complexities of these patient-derived models, both in vitro and in vivo systems, influence both data interpretation and interoperability. To address these challenges, the PDMC Consortium within the National Cancer Institute undertook this review describing the past, present, and future use of PDMCs while providing example vignettes with practical recommendations from the collective experience of the consortium members. For over a century, early researchers sought to study biological organisms in a laboratory setting, leading to the generation of both in vitro and in vivo model systems. Patient-derived models of cancer (PDMCs) have more recently come to the forefront of preclinical cancer models and are even finding their way into clinical practice as part of functional precision medicine programs. The PDMC Consortium, supported by the Division of Cancer Biology in the National Cancer Institute of the National Institutes of Health, seeks to understand the biological principles that govern the various PDMC behaviors, particularly in response to perturbagens, such as cancer therapeutics. Based on collective experience from the consortium groups, we provide insight regarding PDMCs established both in vitro and in vivo, with a focus on practical matters related to developing and maintaining key cancer models through a series of vignettes. Although every model has the potential to offer valuable insights, the choice of the right model should be guided by the research question. However, recognizing the inherent constraints in each model is crucial. Our objective here is to delineate the strengths and limitations of each model as established by individual vignettes. Further advances in PDMCs and the development of novel model systems will enable us to better understand human biology and improve the study of human pathology in the lab. [ABSTRACT FROM AUTHOR]

Simple Summary: Bladder cancer (BLCA) stands as the predominant malignancy within the global urinary system. Small Cajal body-specific RNAs (scaRNAs), constituting a distinct subset of small nucleolar RNAs (snoRNAs), have recently recognized as crucial players in various physiological and pathological processes. The aim of our retrospective study was to elucidate the potential role and mechanism of SCARNA12 in BLCA, offering a foundational understanding the functionalities of scaRNAs. Employing integrated transcriptomic and single-cell proteomic analyses, we comprehensively investigate the impact of SCARNA12 on extracellular matrix (ECM) signaling pathways. Biological experiments provide additional insights into the oncogenic nature of SCARNA12, highlighting its interaction with the transcription factor H2AFZ as a pivotal factor in contributing to the carcinogenesis and progression of BLCA. This study suggests SCARNA12 as a promising diagnostic biomarker and therapeutic target, unveiling its involvement in BLCA through modulation of ECM signaling and interaction with H2AFZ. Background: Small Cajal body-specific RNAs (scaRNAs) are a specific subset of small nucleolar RNAs (snoRNAs) that have recently emerged as pivotal contributors in diverse physiological and pathological processes. However, their defined roles in carcinogenesis remain largely elusive. This study aims to explore the potential function and mechanism of SCARNA12 in bladder cancer (BLCA) and to provide a theoretical basis for further investigations into the biological functionalities of scaRNAs. Materials and Methods: TCGA, GEO and GTEx data sets were used to analyze the expression of SCARNA12 and its clinicopathological significance in BLCA. Quantitative real-time PCR (qPCR) and in situ hybridization were applied to validate the expression of SCARNA12 in both BLCA cell lines and tissues. RNA sequencing (RNA-seq) combined with bioinformatics analyses were conducted to reveal the changes in gene expression patterns and functional pathways in BLCA patients with different expressions of SCARNA12 and T24 cell lines upon SCARNA12 knockdown. Single-cell mass cytometry (CyTOF) was then used to evaluate the tumor-related cell cluster affected by SCARNA12. Moreover, SCARNA12 was stably knocked down in T24 and UMUC3 cell lines by lentivirus-mediated CRISPR/Cas9 approach. The biological effects of SCARNA12 on the proliferation, clonogenic, migration, invasion, cell apoptosis, cell cycle, and tumor growth were assessed by in vitro MTT, colony formation, wound healing, transwell, flow cytometry assays, and in vivo nude mice xenograft models, respectively. Finally, a chromatin isolation by RNA purification (ChIRP) experiment was further conducted to delineate the potential mechanisms of SCARNA12 in BLCA. Results: The expression of SCARNA12 was significantly up-regulated in both BLCA tissues and cell lines. RNA-seq data elucidated that SCARAN12 may play a potential role in cell adhesion and extracellular matrix (ECM) related signaling pathways. CyTOF results further showed that an ECM-related cell cluster with vimentin+, CD13+, CD44+, and CD47+ was enriched in BLCA patients with high SCARNA12 expression. Additionally, SCARNA12 knockdown significantly inhibited the proliferation, colony formation, migration, and invasion abilities in T24 and UMUC3 cell lines. SCARNA12 knockdown prompted cell arrest in the G0/G1 and G2/M phase and promoted apoptosis in T24 and UMUC3 cell lines. Furthermore, SCARNA12 knockdown could suppress the in vivo tumor growth in nude mice. A ChIRP experiment further suggested that SCARNA12 may combine transcription factors H2AFZ to modulate the transcription program and then affect BLCA progression. Conclusions: Our study is the first to propose aberrant alteration of SCARNA12 and elucidate its potential oncogenic roles in BLCA via the modulation of ECM signaling. The interaction of SCARNA12 with the transcriptional factor H2AFZ emerges as a key contributor to the carcinogenesis and progression of BLCA. These findings suggest SCARNA12 may serve as a diagnostic biomarker and potential therapeutic target for the treatment of BLCA. [ABSTRACT FROM AUTHOR]

Simple Summary: Cancer-associated fibroblasts (CAFs) are a key pro-tumorigenic cell type in the tumor microenvironment; however, treatments targeting these cells have shown limited clinical efficacy. In this study, we examined the therapeutic efficacy of CAF depletion using near-infrared photoimmunotherapy (NIR-PIT), a novel technique that selectively targets and depletes specific cells within a tumor. In two tumor models (lung, mammary) with immune-competent mice, selective depletion of fibroblast activation protein (FAP)-expressing cells using NIR-PIT induced interferon-gamma production in tumor-infiltrating CD8 T and natural killer cells and successfully suppressed tumor growth and reduced lung metastasis in the mammary model. These findings highlight the role of CAFs in supporting tumor growth and introduce a promising therapeutic approach for selectively eliminating immunosuppressive FAP+ cells within the tumor microenvironment. Cancer-associated fibroblasts (CAFs) constitute a prominent cellular component of the tumor stroma, with various pro-tumorigenic roles. Numerous attempts to target fibroblast activation protein (FAP), a highly expressed marker in immunosuppressive CAFs, have failed to demonstrate anti-tumor efficacy in human clinical trials. Near-infrared photoimmunotherapy (NIR-PIT) is a highly selective tumor therapy that utilizes an antibody-photo-absorbing conjugate activated by near-infrared light. In this study, we examined the therapeutic efficacy of CAF depletion by NIR-PIT in two mouse tumor models. Using CAF-rich syngeneic lung and spontaneous mammary tumors, NIR-PIT against FAP or podoplanin was performed. Anti-FAP NIR-PIT effectively depleted FAP+ CAFs, as well as FAP+ myeloid cells, and suppressed tumor growth, whereas anti-podoplanin NIR-PIT was ineffective. Interferon-gamma production by CD8 T and natural killer cells was induced within hours after anti-FAP NIR-PIT. Additionally, lung metastases were reduced in the treated spontaneous mammary cancer model. Depletion of FAP+ stromal as well as FAP+ myeloid cells effectively suppressed tumor growth in bone marrow chimeras, suggesting that the depletion of both cell types in one treatment is an effective therapeutic approach. These findings highlight a promising therapy for selectively eliminating immunosuppressive FAP+ cells within the tumor microenvironment. [ABSTRACT FROM AUTHOR]

Simple Summary: Deficiency and targeting of Stabilin-1, which is expressed by liver sinusoidal endothelial cells and subsets of macrophages, has been shown to improve anti-tumor immune responses in preclinical and early clinical studies. This study investigated whether targeting of Stab1 might also influence melanoma liver colonization, as hepatic metastasis of melanoma is a poor prognostic factor. In two models of hepatic melanoma metastasis, no direct influence of anti-Stab1 treatment was found. However, effects on the local microenvironment were observed. We suggest that the organ- and tumor-specific effects of anti-Stab1 therapies should be further considered and analyzed in future human studies. Background: This study analyzed the role of Stabilin-1 on hepatic melanoma metastasis in preclinical mouse models. Methods: In Stabilin-1−/− mice (Stab1 KO), liver colonization of B16F10 luc2 and Wt31 melanoma was investigated. The numbers, morphology, and vascularization of hepatic metastases and the hepatic microenvironment were analyzed by immunofluorescence. Results: While hepatic metastasis of B16F10 luc2 or Wt31 melanoma was unaltered between Stab1 KO and wildtype (Ctrl) mice, metastases of B16F10 luc2 tended to be smaller in Stab1 KO. The endothelial differentiation of both types of liver metastases was similar in Stab1 KO and Ctrl. No differences in initial tumor cell adhesion and retention to the liver vasculature were detected in the B16F10 luc2 model. Analysis of the immune microenvironment revealed a trend towards higher levels of CD45+Gr-1+ cells in Stab1 KO as compared to Ctrl in the B16F10 luc2 model. Interestingly, significantly higher levels of POSTN were found in the matrix of hepatic metastases of Wt31, while liver metastases of B16F10 luc2 showed a trend towards increased deposition of RELN. Conclusions: Hepatic melanoma metastases show resistance to Stabilin-1 targeting approaches. This suggests that anti-Stab1 therapies should be considered with respect to the tumor entity or target organs. [ABSTRACT FROM AUTHOR]

Simple Summary: Muscle-invasive bladder cancer (MIBC) accounts for 25% of bladder cancer cases. Despite the broader usage of immune checkpoint blockades targeting the PD-1/PD-L1 axis, the response rate and survival of patients remain low for this disease. Redirecting these patients swiftly toward alternative therapeutic strategies upon immunotherapy failure should be a priority. So far, no marker allows the early outcome of the treatment to be precisely determined. The aim of our study was to determine to what extent a whole blood transcriptomic analysis could reflect the efficiency of immunotherapy in a well-established MIBC genetic mouse model. We report that it is a valuable approach to predict the response to immunotherapy in our model. Blood-based biomarkers represent ideal candidates for the development of non-invasive immuno-oncology-based assays. However, to date, no blood biomarker has been validated to predict clinical responses to immunotherapy. In this study, we used next-generation sequencing (RNAseq) on bulk RNA extracted from whole blood and tumor samples in a pre-clinical MIBC mouse model. We aimed to identify biomarkers associated with immunotherapy response and assess the potential application of simple non-invasive blood biomarkers as a therapeutic decision-making assay compared to tissue-based biomarkers. We established that circulating immune cells and the tumor microenvironment (TME) display highly organ-specific transcriptional responses to ICIs. Interestingly, in both, a common lymphocytic activation signature can be identified associated with the efficient response to immunotherapy, including a blood-specific CD8+ T cell activation/proliferation signature which predicts the immunotherapy response. [ABSTRACT FROM AUTHOR]