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Critical physical systems with large numbers of molecules can show universal and scaling behaviors. It is of interest to know whether human societies with large numbers of people can show the same behaviors. Here, we use network theory to analyze Chinese history in periods 209 BCE–23 CE and 515–618 CE) related to the Western Han–Xin Dynasty and the late Northern Wei–Sui Dynasty, respectively. Two persons are connected when they appear in the same historical event. We find that the historical networks from two periods separated about 500 years have interesting universal and scaling behaviors, and they are small-world networks; their average cluster coefficients as a function of degree are similar to the network of movie stars. In the historical networks, the persons with larger degrees prefer to connect with persons with a small degree; however, in the network of movie stars, the persons with larger degrees prefer to connect with persons with large degrees. We also find an interesting similar mechanism for the decline or collapse of historical Chinese dynasties. The collapses of the Xin dynasty (9–23 CE) and the Sui dynasty (581–618 CE) were initiated from their arrogant attitude toward neighboring states. [ABSTRACT FROM AUTHOR]

Objective: Immune checkpoint inhibitors (ICIs) have become the standard of care in various cancers, although the predictive tool is still unknown. Methods: This study aimed to develop a novel gene panel by selecting DNA damage response (DDR) genes from the Catalogue of Somatic Mutations in Cancer (COSMIC) databank and validating them in previously reported cohorts. This association between DDR gene mutations and tumor mutation burden or microsatellite status was analysed from The Cancer Genome Atlas (TCGA) databank. Furthermore, we made the gene panel clinically accessible and predicted the response in clinical patients receiving ICIs by using cell‐free DNA. Results: The top 20 mutated DDR genes in various cancers (total 37 genes) were taken from the COSMIC databank, and the DDR genes found to individually predict a response rate > 50% in Van Allen's cohort were selected (Science, 350, 2015 and 207). Eighteen DDR genes were selected as the gene panel. The prevalence and predicted response rate were validated in the other three reported cohorts. Tumor mutational burden‐high was positively associated with mutations of the 18 DDR genes for most cancers. We used cell‐free DNA to test the DDR gene panel and validated by our patients receiving ICIs. This DDR gene panel accounted for approximately 30% of various cancers, achieving a predicted response rate of approximately 60% in patients with a mutated gene panel receiving ICIs. Conclusion: This gene panel is a novel and reliable tool for predicting the response to ICIs in cancer patients and guides the appropriate administration of ICIs in clinical practice. [ABSTRACT FROM AUTHOR]

Simple Summary: The inhibitors of BET proteins represent a promising class of therapeutic agents that target the oncogenic activity of MYC and repress DLBCL cell migration, but the mechanism of such repression remains elusive. Herein, we found that BET inhibitor JQ1 abrogated the amoeboid movement of DLBCL cells through a small GTPase-driven mechanism, including both restrained RAS signaling and MYC-mediated suppression of GTP-RhoA activity. BET inhibition drastically increased the expression of a GTPase regulatory protein, the IQ motif containing GTPase activating protein 3 (IQGAP3), in DLBCL. Proteomics-based re-stratification identified a specific subgroup of DLBCL patients whose tumors harbored an enhanced PI3K activity and had an inferior survival, whereas a lower IQGAP3 expression level further portended a very dismal outcome for those patients. The inhibitors of both BET and RAS (through attenuated PI3K signaling) activities effectively ameliorated the outspread of in vivo DLBCL tumors, indicating the potential of their synergism in the treatment of specific DLBCL subtypes. Phenotypic heterogeneity and molecular diversity make diffuse large B-cell lymphoma (DLBCL) a challenging disease. We recently illustrated that amoeboid movement plays an indispensable role in DLBCL dissemination and inadvertently identified that the inhibitor of bromodomain and extra-terminal (BET) proteins JQ1 could repress DLBCL migration. To explore further, we dissected the impacts of BET inhibition in DLBCL. We found that JQ1 abrogated amoeboid movement of DLBCL cells through both restraining RAS signaling and suppressing MYC-mediated RhoA activity. We also demonstrated that BET inhibition resulted in the upregulation of a GTPase regulatory protein, the IQ motif containing GTPase activating protein 3 (IQGAP3). IQGAP3 similarly exhibited an inhibitory effect on RAS activity in DLBCL cells. Through barcoded mRNA/protein profiling in clinical samples, we identified a specific subgroup of DLBCL tumors with enhanced phosphatidylinositol-3-kinase (PI3K) activity, which led to an inferior survival in these patients. Strikingly, a lower IQGAP3 expression level further portended those with PI3K-activated DLBCL a very dismal outcome. The inhibition of BET and PI3K signaling activity led to effective suppression of DLBCL dissemination in vivo. Our study provides an important insight into the ongoing efforts of targeting BET proteins as a therapeutic approach for DLBCL. [ABSTRACT FROM AUTHOR]

Simple Summary: Patients with advanced intrahepatic cholangiocarcinoma (iCCA) have a very poor prognosis, and no targeted therapy is approved for advanced iCCA. A therapeutic strategy for wild-type p53 cancers is the reactivation of p53 by inhibition of its the negative regulators, MDM2, and WIP1. In the present study, we used HDM201 (an MDM2-p53 binding antagonist) to increase p53 stabilization and upregulate the expression of downstream targets (p21 and MDM2) in RBE and SK-Hep-1 liver adenocarcinoma cell lines. The survival rate and clonogenicity decreased after HDM201 treatment in a dose-dependent manner. Combined treatment with HDM201 and GSK2830371 (WIP1 inhibitor) increased p53 phosphorylation, leading to sustained p53 activation. This combination treatment resulted in G2/M phase arrest and promoted cytotoxicity compared with MDM2 inhibitor monotherapy. Furthermore, increased expression of p53 signaling pathway target genes were identified following combination treatment with HDM201 and GSK2830371, suggesting potential roles for this combination strategy in iCCA therapy. Background: Intrahepatic cholangiocarcinoma (iCCA) is an adenocarcinoma arising from the intrahepatic bile duct. It is the second most common primary liver cancer and has a poor prognosis. Activation of p53 by targeting its negative regulators, MDM2 and WIP1, is a potential therapy for wild-type p53 cancers, but few reports for iCCA or liver adenocarcinoma exist. Methods: Both RBE and SK-Hep-1 liver adenocarcinoma cell lines were treated with the HDM201 (Siremadlin) MDM2-p53 binding antagonist alone or in combination with the GSK2830371 WIP1 phosphatase inhibitor. Cell proliferation, clonogenicity, protein and mRNA expression, cell cycle distribution, and RNA sequencing were performed to investigate the effect and mechanism of this combination. Results: GSK2830371 alone demonstrated minimal activity on proliferation and colony formation, but potentiated growth inhibition (two-fold decrease in GI50) and cytotoxicity (four-fold decrease in IC50) by HDM201 on RBE and SK-Hep-1 cells. HDM201 increased p53 protein expression, leading to transactivation of downstream targets (p21 and MDM2). Combination with GSK2830371 increased p53 phosphorylation, resulting in an increase in both p53 accumulation and p53-dependent trans-activation. G2/M arrest was observed by flow cytometry after this treatment combination. RNA sequencing identified 21 significantly up-regulated genes and five downregulated genes following p53 reactivation by HDM201 in combination with GSK2830371 at 6 h and 24 h time points compared with untreated controls. These genes were predominantly known transcriptional targets regulated by the p53 signaling pathway, indicating enhanced p53 activation as the predominant effect of this combination. Conclusion: The current study demonstrated that GSK2830371 enhanced the p53-dependent antiproliferative and cytotoxic effect of HDM201 on RBE and SK-Hep-1 cells, providing a novel strategy for potentiating the efficacy of targeting the p53 pathway in iCCA. [ABSTRACT FROM AUTHOR]

Cholangiocarcinoma is the most common primary malignant tumor of the bile duct. The current standard first-line treatment for advanced or metastatic cholangiocarcinoma is gemcitabine and cisplatin. However, few effective treatment choices exist for refractory cholangiocarcinoma, and additional therapeutic drugs are urgently required. Our previous work demonstrated that the ALDH isoform 1A3 plays a vital role in the malignant behavior of cholangiocarcinoma and may serve as a new therapeutic target. In this study, we found a positive correlation between ALDH1A3 protein expression levels and the cell migration abilities of three cholangiocarcinoma cell lines, which was verified using ALDH1A3-overexpressing and ALDH1A3-knockdown clones. We also used ALDH1A3-high and ALDH1A3-low populations of cholangiocarcinoma cell lines from the library of integrated network-based cellular signatures (LINCS) program and assessed the effects of ruxolitinib, a commercially available JAK2 inhibitor. Ruxolitinib had a higher cytotoxic effect when combined with gemcitabine. Furthermore, the nuclear translocation STAT1 and STAT3 heterodimers were markedly diminished by ruxolitinib treatment, possibly resulting in decreased ALDH1A3 activation. Notably, ruxolitinib alone or combined with gemcitabine led to significantly reduced tumor size and weight. Collectively, our studies suggest that ruxolitinib might suppress the ALDH1A3 activation through the JAK2/STAT1/3 pathway in cholangiocarcinoma, and trials should be undertaken to evaluate its efficacy in clinical therapy. [ABSTRACT FROM AUTHOR]

Cholangiocarcinoma (CCA) is a malignant tumor with aggressive biological behavior. Immune checkpoints such as cytotoxic T-lymphocyte antigen 4 (CTLA4) and antiprogrammed death 1 (PD-1) are critical immune-checkpoint molecules that repress T-cell activation. The DNA vaccine potential against CTLA4 and PD-1 in CCA is unknown. We used a thioacetamide (TAA)-induced intrahepatic cholangiocarcinoma (iCCA) rat model to investigate the DNA vaccine potential against CTLA4, PD-1, and PD-L1. We detected PD-L1 expression in CCA and CD8+ T-cell infiltration during CCA progression in rats. We validated antibody production, carcinogenesis, and CD8+ T-cell infiltration in rats receiving DNA vaccination against PD-1, PD-L1, or CTLA4. In our TAA-induced iCCA rat model, the expression of PD-L1 and the infiltration of CD8+ T cells increased as in rat CCA tumorigenesis. PD-1 antibodies in rats were not increased after receiving PD-1 DNA vaccination, and CCA tumor growth was not suppressed. However, in rats receiving PD-L1–CTLA4 DNA vaccination, CCA tumor growth was inhibited, and the antibodies of PD-L1 and CTLA4 were produced. Furthermore, the number of CD8+ T cells was enhanced after PD-L1–CTLA4 DNA vaccination. DNA vaccination targeting CTLA4–PD-L1 triggered the production of specific antibodies and suppressed tumor growth in TAA-induced iCCA rats. [ABSTRACT FROM AUTHOR]

Patients with advanced biliary tract cancer (BTC) inevitably experience progression after first-line, gemcitabine-based chemotherapy, due to chemo-resistance. The genetic alterations of DNA damage repair (DDR) genes are usually determined in BTC tumors. In this study, we found that the POLQ mRNA levels are downregulated and the ataxia-telangiectasia mutated (ATM) inhibitor AZD0156 was more sensitive in gemcitabine-resistant BTC sublines than in the parental cell lines. The knockdown of DNA polymerase θ does not affect cell proliferation, but its combination with the ATM inhibitor facilitated cell death in gemcitabine-resistant and gemcitabine-intensive BTC cells. Moreover, in the DNA damage caused by photon, hydrogen peroxide, or chemotherapy drugs, synthetic lethal interactions were found in combination with ATM inhibition by AZD0156 and DNA polymerase θ depletion, resulting in increased DNA damage accumulation and micronucleus formation, as well as reduced cell survival and colony formation. Collectively, our results reveal that ATM acts as a potential target in gemcitabine-resistant and DNA polymerase θ-deficient BTC. [ABSTRACT FROM AUTHOR]

Gemcitabine-based chemotherapy is the current standard treatment for biliary tract cancers (BTCs) and resistance to gemcitabine remains the clinical challenge. TP53 mutation has been shown to be associated with poor clinicopathologic characteristics and survival in patients with BTCs, indicating that p53 plays an important role in the treatment of these cancers. Herein, we comprehensively reviewed previous BTC preclinical research and early clinical trials in terms of p53, as well as novel p53-targeted treatment, alone or in combination with either chemotherapy or other targeted therapies in BTCs. Preclinical studies have demonstrated that p53 mutations in BTCs are associated with enhanced gemcitabine resistance, therefore targeting p53 may be a novel therapeutic strategy for treatment of BTCs. Directly targeting mutant p53 by p53 activators, or indirectly by targeting cell cycle checkpoint proteins (Chk1, ataxia telangiectasia related (ATR), and Wee1) leading to synthetic lethality, may be potential future strategies for gemcitabine-resistant p53 mutated BTCs. In contrast, for wild-type p53 BTCs, activation of p53 by inhibition of its negative regulators (MDM2 and wild-type p53-induced phosphatase 1 (WIP1)) may be alternative options. Combination therapies consisting of standard cytotoxic drugs and novel small molecules targeting p53 and related signaling pathways may be the future key standard approach to beat cancer. [ABSTRACT FROM AUTHOR]

Immune checkpoint inhibitors (ICIs) have become the standard of care in various cancers, although their predictive tools have not yet completely developed. Here, we aimed to exam the role of 70-gene chromosomal instability signature (CIN70) in cancers, and its association with previous predictors, tumor mutation burden (TMB), and microsatellite instability (MSI), for patients undergoing ICIs, as well as the possible predictive value for ICIs. We examined the association of CIN70 with TMB and MSI, as well as the impact of these biomarkers on the survival of 33 cancer cohorts from The Cancer Genome Atlas (TCGA) databank. The predictive value of the ICIs of CIN70 in previously published reports was also validated. Using the TCGA dataset, CIN70 scores were frequently (either positively or negatively) associated with TMB, but were only significantly associated with MSI status in three types of cancer. In addition, our current study showed that all TMB, MSI, and CIN70 had their own prognostic values for survival in patients with various cancers, and that they could be cancer type-specific. In two validation cohorts (melanoma by Hugo et al. and urothelial cancer by Snyder et al.), no significant difference of CIN70 scores was found between responders and non-responders (p-value = 0.226 and 0.108, respectively). In addition, no overall survival difference was noted between patients with a high CIN70 and those with a low CIN70 (p-value = 0.106 and 0.222, respectively). In conclusion, the current study, through a comprehensive bioinformatics analysis, demonstrated a correlation between CIN70 and TMB, but CIN70 is not the predictor for cancer patients undergoing ICIs. Future prospective studies are warranted to validate these findings. [ABSTRACT FROM AUTHOR]

Patients with advanced biliary tract cancer (BTC) have a poor prognosis, and novel treatments are needed. Gemcitabine, the standard of care for BTC, induces DNA damage; however, the ability of cancer cells to repair DNA dampens its effects. To improve the efficacy of gemcitabine, we combined it with MK1775, a Wee1 inhibitor that prevents activation of the G2/M checkpoint. BTC cell lines were treated with gemcitabine only or in combination with MK1775 to determine the therapeutic potential of BTC. Gemcitabine inhibited the growth and induced the apoptosis of four BTC cell lines to a greater extent when added with MK1775 than when added alone. The effects of the combination treatment were observed in both p53 wild-type and p53 mutant cell lines and were unaffected by knockdown of wild-type p53. The combination treatment increased the percentage of apoptotic cells and decreased the percentage of cells synthesizing DNA, suggesting that it caused DNA-damaged cells to accumulate and possibly die in S phase. It did not induce apoptosis when cells were arrested in mitosis using nocodazole. In a xenograft mouse model, gemcitabine plus MK1775 (but not either alone) inhibited the growth of tumors generated from inoculated BTC cells. Our results show that MK1775 highly enhances gemcitabine cytotoxicity in BTC regardless of p53 status. We suggest that the combination treatment elicits a DNA damage response and consequent apoptosis. Our preclinical study provides a basis for future clinical trials of gemcitabine plus MK1775 in patients with BTC. [Display omitted] ● The enhanced antitumor activity of gemcitabine with MK1775 was observed both in vitro and in vivo. ● Combination treatment increased apoptosis and decreased DNA synthesis by accumulating DNA damage and replication stress in the S phase. ● Potentiation of Wee1 inhibition by MK1775 on gemcitabine in BTC cells was p53-independent. [ABSTRACT FROM AUTHOR]

Objective: To investigate the relationship of muscle mass and muscle function with age.Methods and Study Design: The study including 415 participants (aged 60-99 years). Upper (UMM) and lower (LMM) limbs muscle mass and whole body fat free mass (FFM) were measured by bioelectrical impedance analysis. The appendicular skeletal muscle mass (ASM) index (ASM/height2) was calculated. Muscle function was assessed by measuring hand grip strength (HGS) and gait speed.Results: Using ASM index cutoff values we found that higher prevalence of sarcopenia in women than in men (33.5% vs 23.6%, p=0.025). In the upper limb, HGS (β=-0.809) declined more rapidly with age than did UMM (β=-0.592) in men, but not in women (β=-0.389 and β=-0.486 respectively). In the lower limb, gait speed declined more rapidly than LMM in both men (β=-0.683 vs β=-0.442) and women (β=-1.00 vs β=-0.461). The variance of UMM explained 28-29% of the variance of HGS, and LMM explained 7-8% of the variance of gait speed in women and men respectively. In addition to the common predictors (BMI and age), the specific predictors were smoking, exercise and education for FFM and ASM, and smoking, drinking and exercise for HGS (p<0.05).Conclusions: Loss of muscle function is greater than the decline of muscle mass particularly in the upper limbs in men. However, women are more prone to have low muscle mass than the men. Exercise programs need to be designed gender specifically. [ABSTRACT FROM AUTHOR]

Teleost B cells are primitive lymphocytes with both innate and adaptive immune functions. However, the heterogeneity and differentiation trajectory of teleost B cells remain largely unknown. In this study, the landscape of grass carp IgM+ (gcIgM+) B cells was revealed by single-cell RNA sequencing. The results showed that gcIgM+ B cells mainly comprise six populations: (im)mature B cells, innate B cells, proliferating B cells, plasma cells, CD22+ cells, and CD34+ cells, among which innate B cells and proliferating B cells were uncommon B cell subsets with, to our knowledge, new characteristics. Remarkably, three functional IgMs were discovered in grass carp, and a significant percentage of gcIgM+ B cells, especially plasma cells, expressed multiple Igμ genes (Igμ1, Igμ2, and/or Igμ3). More importantly, through single-cell sorting combined with Sanger sequencing, we found that distinct VHDJH recombination patterns of Igμ genes were present in single IgM+ B cells, indicating that individual teleost B cells might produce multiple Abs by coexpressing rearranged IgM subclass genes. Moreover, the percentage of IgM1highIgM2highIgM3high plasma cells increased significantly after bacterial infection, suggesting that individual plasma cells might tend to produce multiple IgMs to resist the infection in teleost fish. In summary, to our knowledge, this study not only helps to uncover the unique heterogeneity of B cells in early vertebrates but also provided significant new evidence supporting the recently proposed "one cell-multiple Abs" paradigm, challenging the classical rule of "one cell-one Ab.", (Copyright © 2023 by The American Association of Immunologists, Inc.)

Cholangiocarcinoma (CCA) exhibits aggressive biological behavior and a poor prognosis. Gemcitabine (GEM)-based chemotherapy is the first-line chemotherapy for advanced CCA but has a response rate of only 20-30%. Therefore, investigating treatments to overcome GEM resistance in advanced CCA is crucial. Among mucin (MUC) family members, MUC4 showed the greatest increase in the resistant versus parental sublines. MUC4 was upregulated in whole-cell lysates and conditioned media from gemcitabine-resistant (GR) CCA sublines. MUC4 mediated GEM resistance by activating AKT signaling in GR CCA cells. The MUC4-AKT axis induced BAX S184 phosphorylation to inhibit apoptosis and downregulated GEM transporter human equilibrative nucleoside transporter 1 (hENT1) expression. The combination of AKT inhibitors and GEM or afatinib overcame GEM resistance in CCA. In vivo, capivasertib (an AKT inhibitor) increased GEM sensitivity in GR cells. MUC4 promoted EGFR and HER2 activation to mediate GEM resistance. Finally, MUC4 expression in patient plasma correlated with MUC4 expression. Paraffin-embedded specimens from non-responders expressed significantly more MUC4 than did those from responders, and this upregulation was associated with poor progression-free survival and overall survival. In GR CCA, high MUC4 expression promotes sustained EGFR/HER2 signaling and AKT activation. The combination of AKT inhibitors with GEM or afatinib might overcome GEM resistance., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Antimicrobial peptides are important components of the host innate immune system, forming the first line of defense against infectious microorganisms. Among them, liver-expressed antimicrobial peptides (LEAPs) are a family of antimicrobial peptides that widely exist in vertebrates. LEAPs include two types, named LEAP-1 and LEAP-2, and many teleost fish have two or more LEAP-2s . In this study, LEAP-2C from rainbow trout and grass carp were discovered, both of which are composed of 3 exons and 2 introns. The antibacterial functions of the multiple LEAPs were systematically compared in rainbow trout and grass carp. The gene expression pattern revealed that rainbow trout and grass carp LEAP-1 , LEAP-2A , LEAP-2B and/or LEAP-2C were differentially expressed in various tissues/organs, mainly in liver. After bacterial infection, the expression levels of LEAP-1 , LEAP-2A , LEAP-2B and/or LEAP-2C in the liver and gut of rainbow trout and grass carp increased to varying degrees. Moreover, the antibacterial assay and bacterial membrane permeability assay showed that rainbow trout and grass carp LEAP-1, LEAP-2A, LEAP-2B and LEAP-2C all have antibacterial activities against a variety of Gram-positive and Gram-negative bacteria with varying levels through membrane rupture. Furthermore, cell transfection assay showed that only rainbow trout LEAP-1, but not LEAP-2, can lead to the internalization of ferroportin, the only iron exporter on cell surface, indicating that only LEAP-1 possess iron metabolism regulation activity in teleost fish. Taken together, this study systematically compared the antibacterial function of LEAPs in teleost fish and the results suggest that multiple LEAPs can enhance the immunity of teleost fish through different expression patterns and different antibacterial activities to various bacteria., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Liu, Hu, Pan, Liu, Jiang, Zhang and Zhang.)

Cholangiocarcinoma (CCA) is the second most common primary liver malignancy and carries a dismal prognosis due to difficulties in achieving an optimal resection, and poor response to current standard-of-care systemic therapies. We previously devised a CTLA4-PD-L1 DNA cancer vaccine (DNA vaccine) and demonstrated its therapeutic effects on reducing tumor growth in a thioacetamide (TAA)-induced rat intrahepatic CCA (iCCA) model. Here, we developed a CTLA4-PD-L1 chimeric protein vaccine (Protein vaccine), and examined its effects in the rat iCCA model. In a therapeutic setting, iCCA-bearing rats received either DNA plus Protein vaccines or Protein vaccine alone, resulting in increased PD-L1 and CTLA-4 antibody titers, and reduced iCCA tumor burden as verified by animal positron emission tomography (PET) scans. Treating iCCA-bearing rats with Protein vaccine alone led to the increase of CTAL4 antibody titers that correlated with the decrease of tumor SUV ratio, indicating regressed tumor burden, along with increased &lt;i&gt;CD8&lt;/i&gt; and granzyme A (&lt;i&gt;GZMA&lt;/i&gt;) expression, and decreased PD-L1 expression on tumor cells. In a preventive setting, DNA or Protein vaccines were injected in rats before the induction of iCCA by TAA. Protein vaccines induced a more sustained PD-L1 and CTLA-4 antibody titers compared with DNA vaccines, and was more potent in preventing iCCA tumorigenesis. Correspondingly, Protein vaccines, but not DNA vaccines, downregulated PD-L1 gene expression and hindered the carcinogenesis of iCCA. Taken together, the CTLA4-PD-L1 chimeric protein vaccine may function both as a therapeutic cancer vaccine and as a preventive cancer vaccine in the TAA-induced iCCA rat model., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Pan, Wu, Huang, Chen, Lan and Yeh.)

Intrahepatic cholangiocarcinoma (iCCA) is an adenocarcinoma arising from the intrahepatic bile duct and accounts for the second highest incidence of primary liver cancers after hepatocellular carcinoma. The lack of effective treatment leads to a poor prognosis for advanced iCCA, so new targeted therapy is needed. The impairment of wild-type (WT) p53 tumor suppressor function by its negative regulators frequently occurs in iCCA. Therefore, restoration of WT p53 function by inhibiting its negative regulators is a therapeutic strategy being explored for cancer treatment. Combining an MDM2 inhibitor (MDM2i, RG7388) to stabilize p53 and a WIP1 inhibitor (WIP1i, GSK2830371) to increase p53 phosphorylation enhances p53 function. The combination of MDM2 and WIP1 inhibitors has been reported in several cancer types but in vivo studies are lacking. In the current study, liver adenocarcinoma cell lines, RBE and SK-Hep-1, were treated with RG7388 alone and in combination with GSK2830371. Cell proliferation, clonogenicity, protein and mRNA expressions, and cell cycle distribution were performed to investigate the effect and mechanism of growth suppression. To evaluate the antitumor efficacy of RG7388 and GSK2830371 in vivo , SK-Hep-1 xenografts in NOD-SCID mice were treated with combination therapy for two weeks. The combination of MDM2i and WIP1i significantly increased the growth inhibition, cytotoxicty, p53 protein expression, and phosphorylation (Ser15), leading to transactivation of downstream targets (p21 WAF1 and MDM2). The in vivo results demonstrated that the combination treatment can significantly inhibit tumor growth. In this study, the liver adenocarcinoma cell lines responded to combination treatment via reactivation of p53 function evidenced by increased p53 expression, phosphorylation and expression of its downstream targets. This efficacy was also demonstrated in vivo . The current research provides a novel strategy for targeting the p53 pathway in liver adenocarcinoma that warrants further investigation., Competing Interests: None., (AJCR Copyright © 2022.)

KIT and PDGFRA play a major role in the oncogenic process in gastrointestinal stroma tumors (GIST) and small molecules have been employed with great success to target the KIT and PDGFRA pathways in this cancer. However, approximately 10% of patients with GIST are resistant to current targeted drug therapy. There is a need to explore other potential targets. Although p53 alterations frequently occur in most cancers, studies regarding p53 in GIST have been limited. The CDKN2A/MDM2/p53 axis regulates cell cycle progression and DNA damage responses, which in turn control tumor growth. This axis is the major event required for transformation from low- to high-risk GIST. Generally, p53 mutation is infrequent in GIST, but p53 overexpression has been reported to be associated with high-risk GIST and unfavorable prognosis, implying that p53 should play a critical role in GIST. Also, Wee1 regulates the cell cycle and the antitumor activity of Wee1 inhibition was reported to be p53 mutant dependent. In addition, Wee1 was reported to have potential activity in GIST through the regulation of KIT protein and this mechanism may be dependent on p53 status. In this article, we review previous reports regarding the role of p53 in GIST and propose targeting the p53 pathway as a novel additional treatment strategy for GIST., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wu, Chen, Huang, Pan, Aptullahoglu, Yeh and Lunec.)

Podosomes are dynamic actin-based membrane protrusions that are important for extracellular matrix degradation and invasive cell motility. Individual podosomes are often found to organize into large rosette-like structures in some types of cells, such as osteoclasts, endothelial cells, Src-transformed fibroblasts, and certain highly invasive cancer cells. In this study, we show that new podosome rosettes arise through one of two mechanisms; de novo assembly or fission of a pre-existing podosome rosette in Src-transformed fibroblasts. Fission is a more efficient way than de novo assembly to generate new podosome rosettes in these cells. Podosome rosettes undergoing fission possess higher motility and a stronger matrix-degrading capability. Podosome rosette fission may be the result of polarized myosin II-mediated contractility of these structures, which is coordinately regulated by myosin light chain kinase and Rho-associated kinase II. Collectively, this study unveils a previously unknown mechanism-fission for the biogenesis of podosome rosettes.

Podosomes are actin-based membrane protrusions that facilitate extracellular matrix degradation and motility of invasive cells. Podosomes can self-organize into large rosette-like structures in Src-transformed fibroblasts, osteoclasts and some highly invasive cancer cells. However, the mechanism of this assembly remains obscure. In this study, we show that the suppression of Jun N-terminal kinase (JNK) by the JNK inhibitor SP600125 or short-hairpin RNA inhibited podosome rosette formation in SrcY527F-transformed NIH3T3 fibroblasts. In addition, SrcY527F was less able to induce podosome rosettes in JNK1-null or JNK2-null mouse embryo fibroblasts than in wild-type counterparts. The kinase activity of JNK was essential for promoting podosome rosette formation but not for its localization to podosome rosettes. Moesin, a member of the ERM (ezrin, radixin and moesin) protein family, was identified as a substrate of JNK. We show that the phosphorylation of moesin at Thr558 by JNK was important for podosome rosette formation in SrcY527F-transformed NIH3T3 fibroblasts. Taken together, our results unveil a novel role of JNK in podosome rosette formation through the phosphorylation of moesin.

Podosomes are actin-enriched membrane protrusions that play important roles in extracellular matrix degradation and invasive cell motility. Podosomes undergo self-assembly into large rosette-like structures in Src-transformed fibroblasts, osteoclasts and certain highly invasive cancer cells. Several protein tyrosine kinases have been shown to be important for the formation of podosome rosettes, but little is known regarding the role of protein tyrosine phosphatases in this process. We found that knockdown of the Src homolog domain-containing phosphatase 2 (SHP2) significantly increased podosome rosette formation in Src-transformed fibroblasts. By contrast, SHP2 overexpression suppressed podosome rosette formation in these cells. The phosphatase activity of SHP2 was essential for the suppression of podosome rosette formation. SHP2 selectively suppressed the tyrosine phosphorylation of Tks5, a scaffolding protein required for podosome formation. The inhibitory effect of SHP2 on podosome rosette formation was associated with the increased activation of Rho-associated kinase (ROCK) and the enhanced polymerization of vimentin filaments. A higher content of polymerized vimentin filaments was correlated with a lower content of podosome rosettes. Taken together, our findings indicate that SHP2 serves as a negative regulator of podosome rosette formation through the dephosphorylation of Tks5 and the activation of ROCK-mediated polymerization of vimentin in Src-transformed fibroblasts.

Podosomes are dynamic actin-enriched membrane structures that play an important role in invasive cell motility and extracellular matrix degradation. They are often found to assemble into large rosettelike structures in highly invasive cells. However, the mechanism of this assembly remains obscure. In this study, we identified focal adhesion kinase (FAK) as a key molecule necessary for assembly. Moreover, phosphorylation of p130Cas and suppression of Rho signaling by FAK were found to be important for FAK to induce the assembly of podosome rosettes. Finally, we found that suppression of vimentin intermediate filaments by FAK facilitates the assembly of podosome rosettes. Collectively, our results strongly suggest a link between FAK, podosome rosettes, and tumor invasion and unveil a negative role for Rho signaling and vimentin filaments in podosome rosette assembly.

Tumor metastasis might be evoked in response to microenvironmental stress, such as a shortage of oxygen. Although the cellular response to hypoxia has been well established, we know little about how tumors adapt themselves to deprivation of growth factor. Protein kinase Cdelta (PKCdelta), a stress-sensitive protein kinase, has been implicated in tumor progression. In this study, we demonstrate that elevated expression of PKCdelta in Madin-Darby canine kidney cells induces a scatter response upon serum starvation, a condition that mimics growth-factor deprivation. Serum starvation stimulates the catalytic activity and Y311 phosphorylation of PKCdelta through reactive oxygen species (ROS) and the Src family kinases. Mutation of PKCdelta at Y311 and Y322, both of which are phosphorylation sites for Src, impairs its activation and ability to promote cell scattering upon serum deprivation. Once activated by ROS, PKCdelta itself activates ROS production at least partially through NADPH oxidase. In addition, the c-Jun N-terminal kinase is identified as a crucial downstream mediator of ROS and PKCdelta for induction of cell scattering upon serum deprivation. We demonstrate that the C1B domain of PKCdelta is essential not only for its localization at the Golgi complex, but also for its activation and ability to induce cell scattering upon serum deprivation. Finally, depletion of PKCdelta in human bladder carcinoma T24 cells restores their cell-cell contacts, which thereby reverses a scattered growth pattern to an epithelial-like growth pattern. Collectively, our results suggest that elevated expression of PKCdelta might facilitate the scattering of cells in order to escape stress induced by growth-factor deprivation.