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Cutaneous T cell lymphoma (CTCL) is a T cell-derived non-Hodgkin lymphoma primarily affecting the skin, with treatment posing a significant challenge and low survival rates. In this study, we investigated the anti-cancer potential of Neosetophomone B (NSP-B), a fungal-derived secondary metabolite, on CTCL cell lines H9 and HH. Cell viability was measured using Cell counting Kit-8 (CCK8) assays. Apoptosis was measured by annexin V/PI dual staining. Immunoblotting was performed to examine the expression of proteins. Applied Biosystems' high-resolution Human Transcriptome Array 2.0 was used to examine gene expression. NSP-B induced apoptosis in CTCL cells by activating mitochondrial signaling pathways and caspases. We observed downregulated expression of BUB1B, Aurora Kinases A and B, cyclin-dependent kinases (CDKs) 4 and 6, and polo-like kinase 1 (PLK1) in NSP-B treated cells, which was further corroborated by Western blot analysis. Notably, higher expression levels of these genes showed reduced overall and progression-free survival in the CTCL patient cohort. FOXM1 and BUB1B expression exhibited a dose-dependent reduction in NSP-B-treated CTCL cells.FOXM1 silencing decreased cell viability and increased apoptosis via BUB1B downregulation. Moreover, NSP-B suppressed FOXM1-regulated genes, such as Aurora Kinases A and B, CDKs 4 and 6, and PLK1. The combined treatment of Bortezomib and NSP-B showed greater efficacy in reducing CTCL cell viability and promoting apoptosis compared to either treatment alone. Our findings suggest that targeting the FOXM1 pathway may provide a promising therapeutic strategy for CTCL management, with NSP-B offering significant potential as a novel treatment option. • Cutaneous T cell lymphoma (CTCL) is primarily affecting the skin, posing a significant challenge and low survival rates. • Anticancer activity of NSP-B, a secondary fungal metabolite isolated from Neosetophoma sp , has not been explored in cancer cells. • NSP-B inhibited activation of FOXMI/BUB1B and its associated signaling in CTCL cells. • NSP-B suppressed cell proliferation and inhibited apoptosis via activation of mitochondrial-caspase signaling in CTCL. • NSP-B could be a novel anticancer drug for the treatment of CTCL and other hematological malignancies. [ABSTRACT FROM AUTHOR]

Combination therapy is widely used in cancer medicine due to the benefits of drug synergy and the reduction of acquired resistance. To minimize emergent toxicities, nanomedicines containing drug combinations are being developed, and they have shown encouraging results. However, developing multi-drug loaded nanoparticles is highly complex and lacks predictability. Previously, it was shown that single drugs can self-assemble with near-infrared dye, IR783, to form cancer-targeted nanoparticles. A structure-based predictive model showed that only 4% of the drug space self-assembles with IR783. Here, we mapped the self-assembly outcomes of 77 small molecule drugs and drug pairs with IR783. We found that the small molecule drug space can be divided into five types, and type-1 drugs self-assemble with three out of four possible drug types that do not form stable nanoparticles. To predict the self-assembly outcome of any drug pair, we developed a machine learning model based on decision trees, which was trained and tested with F1-scores of 89.3% and 87.2%, respectively. We used literature text mining to capture drug pairs with biological synergy together with synergistic chemical self-assembly and generated a database with 1985 drug pairs for 70 cancers. We developed an online search tool to identify cancer-specific, meta-synergistic drug pairs (both chemical and biological synergism) and validated three different pairs in vitro. Lastly, we discovered a novel meta-synergistic pair, bortezomib-cabozantinib, which formed stable nanoparticles with improved biodistribution, efficacy, and reduced toxicity, even over single drugs, in an in vivo model of head and neck cancer. [Display omitted] • Small molecule drug pairs can be divided into five types according to their self assembly with IR783 stabilizer. • Type-1 drugs can self-assemble and efficiently stabilize four different drug types in IR783 combination nanoparticles. • A machine learning model based on decision trees predicts self-assembly outcomes of any drug pair with high accuracy. • Generated a database of meta-synergistic drug pairs for 70 cancers, with an online search tool for cancer-specific drug pairs. • Meta-synergistic pair, bortezomib-cabozantinib, showed enhanced biodistribution, efficacy, and reduced toxicity in HNSCC. [ABSTRACT FROM AUTHOR]

Considerable evidence suggests that breast cancer therapeutic resistance and relapse can be driven by polyploid giant cancer cells (PGCCs). PGCCs are involved in tumor repopulation following radiotherapy. Although the majority of PGCCs induced by irradiation underwent cell death, some exhibited proliferative capacity, and the number increases with the stages of disease and therapeutic stress. Given the importance of PGCCs, it remains challenging to dig effective anti-PGCCs therapy. In this study, we propose identifying promising radiotherapy with repurposed old drugs combination therapy to inhibit all cancer cells or only PGCCs. In this manner, we screen a drug library combined with irradiation and identify promising combination therapy that inhibit all cancer cells or only PGCCs (e.g., regulators of HDAC, proteasome, and ferroptosis). (1) PGCCs Inducing : The breast cancer cell line MDA‐MB‐231, SUM-159, SUM-149 cells were irradiated with various doses X-rays (0 Gy, 2 Gy, 4 Gy, 8 Gy, 10 Gy) using a linear accelerator, after 5-day culture, we harvest irradiation‐induced PGCCs and do drug screening experiments. (2) Drug library Setting : We make up a library including 4000 compounds (NIH Anti-cancer Compound Library (96-well)-L3000) and small targeting compounds). (3) Combination therapy screening and PGCCs cell toxicity test : We screen the drug library, the drug combination and irradiation combined with drug library. Then based on the single-cell morphological analysis pipeline for the swift differentiation of compounds targeting non-PGCCs, PGCCs, or both, which was published in the previous study, we identify PGCCs and make PGCCs cell toxicity analysis to find out promising anti-PGCCs treatments. (4) Statistical analyses were conducted using R (version 4.1), scientific 2-D graphing and statistics software, and a programming environment. Two-tailed Student's t-test compared two groups, while paired 2-way ANOVA and Fisher's Least Significant Difference (LSD) test compared multiple groups, significance set at P < 0.05 (*P < 0.05, **P < 0.01, ***P < 0.001). (1) PGCCs existed after various dose of irradiation (2, 4, 8, 10 Gy), and the percentage of these PGCCs grew rapidly in the following days, reaching peak value around day 5. (2) Irradiation combined with some drugs could kill PGCCs induced by irradiation, such as Bortezomib, MG-132, Carfilzomib, Ixazomib (proteasome inhibitors), Imidazole ketone erastin (IKE), RSL3, FINO2, ML162, ML210 (ferroptosis inducers), Vorinostat (SAHA), Romidepsin, Panobinostat (HADC inhibitors). While the importance of PGCCs in cancer treatment resistance has been widely acknowledged, there is no effective way to eradicate them. This study identified 3 main classes of compounds effectively killed irradiation induced PGCCs combined with irradiation: HDAC inhibitors, proteasome inhibitors, and ferroptosis inducers. Further mechanistic and in vivo investigations will be performed in our future research endeavors inducers. [ABSTRACT FROM AUTHOR]

Dysfunction of the ubiquitin‒proteasome system can induce sustained endoplasmic reticulum stress (ERS) and subsequent cell death. However, malignant cells have evolved multiple mechanisms to evade sustained ERS. Therefore, identification of the mechanisms through which tumor cells develop resistance to ERS is important for the therapeutic exploitation of these cells for drug-resistant tumors. Herein, we found that proteasome inhibitors could induce ERS, activate ferroptosis signaling, and thereby induce the adaptive tolerance of tumor cells to ERS. Mechanistically, the activation of ferroptosis signaling was found to promote the formation and secretion of exosomes containing misfolded and unfolded proteins, which resulted in rescuing ERS and promoting tumor cell survival. The inhibition of ferroptosis signaling synergized with bortezomib, a clinically used proteasome inhibitor, to suppress the viability of hepatocellular carcinoma cells in vitro and in vivo. The present findings reveal that ERS resistance can be driven by an ERS-ferroptosis signaling-exosome pathway and have important clinical implications for intracellular signaling, ER homeostasis and drug-resistant cancer therapy. [Display omitted] • Ferroptosis signaling activated by proteasome inhibitors could induce the adaptive tolerance of tumor cells to ERS. • Ferroptosis signaling promotes the secretion of exosomes containing misfolded proteins, thus rescuing ERS and cell death. • The inhibition of ferroptosis signaling synergized with bortezomib could suppress the viability of hepatoma cells. [ABSTRACT FROM AUTHOR]

Dendritic cells (DCs), the primary antigen-presenting cells in the immune system, play a critical role in regulating tumor immune responses. However, the tumor immunosuppressive microenvironment severely impedes the process of antigen-presenting and DC maturation, thereby limiting the efficacy of cancer immunotherapy. In this work, a pH-responsive polymer nanocarrier (PAG) modified with aminoguanidine (AG) was constructed for the efficient delivery of bortezomib (BTZ) through bidentate hydrogen bonds and electrostatic adsorption formed between guanidine groups of PAG and boronic acid groups of BTZ. The obtained PAG/BTZ nanoparticles exhibited pH-responsive release of BTZ and AG in the acidic tumor microenvironment. On the one hand, BTZ induced potent immune activation by eliciting immunogenic cell death (ICD) and releasing damage-associated molecular patterns. On the other hand, the cationic AG significantly promoted antigen uptake by DCs and activated DC maturation. As a result, PAG/BTZ significantly stimulated tumoral infiltration of cytotoxic T lymphocytes (CTLs) and triggered robust antitumor immune responses. Thus, it showed potent antitumor efficacy when synergizing with an immune checkpoint-blocking antibody. A pH-responsive aminoguanidine (AG)-modified nanoparticle (PAG/BTZ) for tumoral delivery of bortezomib (BTZ) was fabricated successfully to improve the chemo-immunotherapy efficacy by eliciting immunogenic cell death (ICD), promoting dendritic cells (DCs) maturation, and synergizing with an immune checkpoint-blocking antibody (α-PDL1). [Display omitted] • The PAG/BTZ nanoparticles induced strong tumor immunogenic cell death to increase the immunogenicity. • The PAG/BTZ nanoparticles improved chemo-immunotherapy efficacy by activating DCs and promoting their maturation. • The PAG/BTZ showed potent antitumor efficacy when synergizing with an immune checkpoint-blocking antibody (αPD-L1). [ABSTRACT FROM AUTHOR]

The use of plant extracts by cancer patients during chemotherapy poses potential risks, as they may reduce the effectiveness of treatment or interact negatively with chemotherapeutic drugs. There is a lack of comprehensive studies evaluating the effects of various Centaurea spp. plant extracts on chemotherapy outcomes, highlighting the need for caution and medical supervision. Therefore, the aim of this study was to evaluate the effects of five Centaurea spp. extracts in concentrations of 125 μg/ml and 250 μg/ml on the cytotoxicity induced by doxorubicin (DOX, 1 μM) in MCF-7 breast cancer cells and by bortezomib (BOR, 7 nM) in PC-3 prostate cancer cells. Selected cell lines were treated with drugs and extracts or combined for 48 h. Biological assays revealed that four out of five tested extracts abolished the cytotoxic effects of DOX and BOR. The extracts showed low antioxidant activity compared to Trolox, with no correlation to total compound content, indicating the abolition of the cytotoxic effect was not due to antioxidant activity. However, genotoxicity and DNA damage response studies showed a protective effect of the extract on the DNA of cancer cells and upregulation of DNA repair, which may underlie the reversal of the chemotherapy effect. • Impact of Centaurea spp. extracts on DOX-induced cytotoxicity in MCF-7 cells and BOR-induced cytotoxicity in PC-3 cells. • CAL, CDC, CAP, and CST extracts abolished the cytotoxic effects of DOX and BOR in both cell lines. • Extracts showed low antioxidant activity, uncorrelated to compound content, and no effect on drug-induced oxidative stress. • The combination of extract and chemotherapy increased DNA repair gene expression and reduced DNA damage in both cell lines. [ABSTRACT FROM AUTHOR]

The tRNA methyltransferase DNMT2 (TRDMT1) plays a crucial role in various biological functions; however, its role in cancer, particularly in liver cancer, remains incompletely understood. In this study, we demonstrate that high DNMT2 expression is negatively correlated with prognosis in clinical liver cancer patients. A series of in vitro and in vivo experiments showed that DNMT2 promotes the proliferation, colony formation, and metastasis of hepatocellular carcinoma cells. We identified the pro-apoptotic gene TNFSF10 (TRAIL) as a downstream target of DNMT2 , regulated by the N6-methyladenosine (m6A) demethylase FTO. Epigenetically, DNMT2 deletion increased FTO expression, leading to a reduction in m6A methylation levels. FTO upregulated TNFSF10 expression, significantly reducing the proliferation and metastasis of DNMT2 -deficient hepatocellular carcinoma cells. Furthermore, DNMT2 deletion was shown to significantly upregulate chemokine expression in tumors. Finally, we demonstrated that the NF-κB inhibitor Bortezomib further enhances DNMT2 deletion-induced apoptosis in hepatocellular carcinoma cells. This study reveals DNMT2 's role in liver cancer and presents a new therapeutic target for future treatments. • DNMT2 promoted the proliferation colony formation and metastasis of hepatocellular carcinoma cells. • The proapoptotic gene TNFSF10 (TRAIL) as a downstream target of DNMT2 and mediated by N6-methyladenosine (m6A) modification. • We proved that NF-κB inhibitor Bortezomib can further enhance DNMT2 deletion induced apoptosis in hepatocellular carcinoma cells. [ABSTRACT FROM AUTHOR]

This work represents the first successful application of a molecularly imprinted polymer (MIP)-based electrochemical sensor for the sensitive and selective determination of the first developed proteasome inhibitor, bortezomib (BOR). BOR is used for the treatment of multiple myeloma, gastrointestinal stromal tumors, and mantle cell lymphoma. It shows its desired effect through the boronate group and can be administered intravenously or subcutaneously. The MIP-based electrochemical sensor design includes the integration of green-synthesized saffron-based copper nanoflowers (CuNFs) from Crocus sativus L. to increase the active surface area and porosity of the glassy carbon electrode (GCE) surface. 2-Acrylamido-2-methyl-1-propanesulfonic acid (AMPS) was selected as the functional monomer along with other MIP components. Detailed characterizations of the developed CuNFs/AMPS/MIP-GCE sensor and CuNFs were performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The indirect measurement approach using 5.0 mM [Fe(CN) 6 ]3–/4– solution was used to determine BOR in the linear range of 2.5 × 10−13 M − 2.5 × 10−12 M (0.25–2.5 pM). The LOD and LOQ values of the sensor obtained at the fM level (29 fM and 96.7 fM), which has a linear response in the commercial human serum sample in the same concentration range, emphasize its sensitivity (1.89 × 1013 and 2.14 × 1013 μA/M for standard solution and serum). The repeatability and reproducibility of the sensor were between 0.87 % and 2.17 %, showing its reliability. The successful performance of the sensor in the presence of metabolites belonging to BOR demonstrates its unique selectivity. The selectivity was demonstrated via relative imprinting factor (IF') values (higher than 3.5) against BOR's metabolites. The stability of the CuNFs/AMPS/MIP-GCE sensor was found to be 5 days. [Display omitted] • The first MIP-based electrochemical sensor for BOR determination. • Green synthesized saffron copper nanoflowers supported MIP for better performance. • Good analytical performance in commercial human serum and medicinal product samples. • The sensor indicates a detection ranging from 0.25 pM to 2.5 pM with a LOD of 29.0 fM. [ABSTRACT FROM AUTHOR]

• JQ-1 and bortezomib cooperate to induce DNA damage and cell death in MM and PEL cells. • JQ-1/bortezomib-induced cell death involves c-Myc downregulation and mTOR dephosphorylation. • JQ-1 and bortezomib activate autophagy and UPR as prosurvival mechanisms. Multiple myeloma (MM) and primary effusion lymphoma (PEL) are two aggressive hematologic cancers against which bortezomib and JQ-1, proteasome and bromodomain and extraterminal domain (BET) inhibitors, respectively, have been shown to have a certain success. However, the combination of both seems to be more promising than the single treatments against several cancers, including MM. Indeed, in the latter, proteasome inhibition upregulated nuclear respiratory factor 1 (NRF1), and such a prosurvival effect was counteracted by BET inhibitors. In the present study, we found that JQ-1/bortezomib induced a strong cytotoxic effect against PEL and discovered new insights into the cytotoxic mechanisms induced by such a drug combination in PEL and MM cells. In particular, a stronger c-Myc downregulation, leading to increased DNA damage, was observed in these cells after treatment with JQ-1/bortezomib than after treatment with the single drugs. Such an effect contributed to mechanistic target of rapamycin (mTOR)–phosphorylated eukaryotic translation initiation factor 4E–binding protein 1 (p-4EBP1) axis inhibition, also occurring through c-Myc downregulation. However, besides the prodeath effects, JQ-1/bortezomib activated unfolded protein response (UPR) and autophagy as prosurvival mechanisms. In conclusion, this study demonstrated that JQ-1/bortezomib combination could be a promising treatment for MM and PEL, unveiling new molecular mechanisms underlying its cytotoxic effect, and suggested that UPR and autophagy inhibition could be exploited to further potentiate the cytotoxicity of JQ-1/bortezomib. . [Display omitted]. [ABSTRACT FROM AUTHOR]

Chemodynamic therapy (CDT), an emerging tumor-specific therapeutic modality, is frequently restrained by insufficient intratumoral Fenton catalysts and increasingly inefficient catalysis caused by the continuous consumption of limited H 2 O 2 within tumors. Herein, we engineered a pH-responsive bortezomib (BTZ) polymer prodrug catalytic nanoreactor (He Zn@HA-BTZ) capable of self-supplying Fenton catalyst and H 2 O 2. It is aimed for tumor-specific chemo/chemodynamic therapy via oxidative stress and endoplasmic reticulum (ER) stress dual-amplification and macrophage repolarization. A catechol‑boronate bond-based hyaluronic acid-BTZ prodrug HA-DA-BTZ was modified on Hemin and Zn2+ coordination nanoscale framework (He Zn), an innovative CDT inducer, to construct He-Zn@HA-BTZ. He-Zn@HA-BTZ with good stability and superior peroxidase-like activity preferentially accumulated at tumor sites and be actively internalized by tumor cells. Under the cleavage of catechol‑boronate bond in acidic endo/lysosomes, pre-masked BTZ was rapidly released to induce ubiquitinated protein aggregation, robust ER stress and elevated H 2 O 2 levels. The amplified H 2 O 2 was further catalyzed by He Zn via Fenton-catalytic reactions to produce hypertoxic •OH, enabling cascaded oxidative stress amplification and long-lasting effective CDT, which in turn aggravated BTZ-induced ER stress. Eventually, a dual-amplification of oxidative stress and ER stress was achieved to initiate cell apoptosis/necrosis with reduced BTZ toxicity. Intriguingly, He-Zn@HA-BTZ could repolarize macrophages from M2 to antitumor M1 phenotype for potential tumor therapy. This "all in one" prodrug nanocatalytic reactor not only enriches the CDT inducer library, but provides inspirational strategy for simultaneous oxidative stress and ER stress based excellent cancer therapy. [Display omitted] • A pH-activitable bortezomib polymer prodrug catalytic nanoreactor is constructed. • Nanosized He Zn with peroxidase activity is employed as an innovative CDT reagent. • This nanorector work by cascaded oxidative stress and ER stress dual-amplification. • The system can serve as potential M1 macrophage educator for future immunotherapy. [ABSTRACT FROM AUTHOR]

• Immune thrombocytopenic thrombotic purpura is due to anti-ADAMTS13 autoantibodies. • One in six patients are refractory to initial plasma exchange and steroids. • Thirteen percent relapse despite early use of CD20-targeted anti-B cell therapy. • CD20 negative plasma cells are a reservoir for chronic autoantibody production. • We review anti-plasma cell therapy in immune thrombotic thrombocytopenic purpura. Immune thrombotic thrombocytopenic purpura (iTTP) is a microangiopathic hemolytic anemia (MAHA) underpinned by autoreactivity against the von Willebrand factor (vWF) cleaving protease, ADAMTS13 (a d isintegrin a nd m etalloproteinase with a t hrombo s pondin type 1 motif, member 13). Autoantibody mediated ADAMTS13 inhibition leads to the accumulation of ultra-large vWF multimers which activate platelets and endothelium to initiate microvascular thrombosis. In the absence of urgent therapeutic intervention, iTTP is rapidly fatal due to cumulative organ dysfunction including catastrophic neurological and cardiac sequalae. Therapeutic plasma exchange (TPE) is the mainstay of initial therapy and aims to remove pathological autoantibodies and ultra-large vWF multimers while replenishing ADAMTS13. Immunosuppression is an important treatment adjunct, as attainment of remission and successful TPE cessation is strongly associated with suppression of anti-ADAMTS13 antibody production. More recently, caplacizumab, an antibody fragment blocking the interaction between vWF multimers and platelets, has been incorporated into acute TTP management to mitigate end-organ damage while awaiting suppression of anti-ADAMTS13 activity. In most cases, remission is achieved using corticosteroids alone or in combination with the B-cell depleting antibody, rituximab. However, some patients are refractory to front-line immunosuppression in the context of 'inhibitor boosting' whereby the exposure to homologous plasma exacerbates the underlying autoimmune flare. As such cases have been observed in the context of likely effective B-cell depletion, it has been hypothesized that plasma cells (ie, terminally differentiated B-cells) may provide a therapy-resistant nidus of anti-ADAMTS13 production as has been demonstrated in other autoimmune disease settings. Autoreactive plasma cells can be targeted by conventional and novel therapeutics, including those developed for malignant plasma cells in the context of multiple myeloma. Here we review the rationale and evidence for plasma cell directed therapy in refractory iTTP, with a focus on the proteasome inhibitor, bortezomib, and the CD38 monoclonal antibody, daratumumab. [ABSTRACT FROM AUTHOR]

• Relapsed refractory warm autoimmune hemolytic anemia (wAIHA) represents an unmet clinical need. • Innovative treatments in this setting include bortezomib, fostamatinib, parsaclisib, and recombinant erythropoietin. • Published studies show good efficacy although in small and heterogenous populations with a short follow up. • Trials are running with ibrutinib, rilzabrutinib, daratumumab, isatuximab, complement and neonatal Fc receptor inhibitors. In this review article we provide a critical insight into recent reports evaluating innovative therapies for warm type autoimmune hemolytic anemia (wAIHA). Among published articles, we selected two reports on the use of the proteasome inhibitor bortezomib in association with dexamethasone or rituximab, one study on the spleen tyrosine kinase inhibitor fostamatinib, and a retrospective study on recombinant erythropoietin (rEPO). Among recent scientific communications, we discussed a report on the phosphoinositide 3-kinase delta inhibitor (PI3Kδi) parsaclisib. All studies highlighted a good efficacy although to be confirmed in larger trials and with limitations due to the heterogeneity of wAIHA patients enrolled, the small number of subjects, the concomitant medications allowed, and the short follow-up. Ongoing trials include new B-cell/plasma-cell targeting agents such as the Bruton tyrosine kinase inhibitors ibrutinib and rilzabrutinib, and the anti-CD38 MoAbs daratumumab and its analogue isatuximab. Further drugs in clinical trials target the complement cascade in wAIHA with complement activation, such as the C3 inhibitor pegcetacoplan and the C1q inhibitor ANX005. Finally, an interesting and non-immuno-toxic strategy is to remove the pathogenic autoantibodies via blocking the neonatal Fc receptor, by intravenous nipocalimab and subcutaneous RVT-1401. Such novel agents targeting the several immunopathological mechanisms acting in wAIHA and their possible combination, will increase the therapeutic armamentarium and possibly fill the gap of wAIHA relapsed after/refractory to rituximab. Moreover, these new target therapies may represent a tool for the unmet need of very acute cases. [ABSTRACT FROM AUTHOR]

Bortezomib targets UBE2Q1 and inhibits its activity, thereby regulating DDX3 ubiquitination, which in turn induces cell apoptosis and enhances αPD-1 efficacy. [Display omitted] • UBE2Q1 has elevated expression in CML with T315I mutation and interacts with DDX3. • Bortezomib targets UBE2Q1 and decreases protein expression. • Bortezomib induces CML-T315I cells apoptosis as well as enhances the therapeutic effects of αPD-1 efficacy. The BCR:ABL T315I mutation presents a significant challenge in the current management of Chronic Myeloid Leukemia (CML), highlighting the need to identify novel targets and drugs. In our study, we observed the elevated expression of UBE2Q1 in KBM5-T315I cells compared to KBM5 cells, where it interacted with DDX3, regulating its ubiquitination. Furthermore, we found that Bortezomib (BTZ) targeted UBE2Q1, reducing its protein level expression. Consequently, BTZ dose-dependently inhibited the growth vitality of KBM5-T315I cells, inducing increased ROS production, mitochondrial membrane potential collapse, cytochrome C release, and expression of apoptosis-related proteins. These events collectively induced apoptosis in KBM5-T315I cells. Moreover, BTZ enhanced the therapeutic effects of anti-PD-1 treatment. In NOD/SCID mice bearing KBM5-T315I cell line xenografts, BTZ administration (2 mg/kg, ip, every other day for 4 weeks) significantly inhibited the growth of KBM5-T315Iderived xenografts and extended survival. In conclusion, our study sheds new light on the BTZ-induced apoptosis mechanism, suggesting the potential of BTZ as a promising chemo-immunotherapy agent against BCR:ABL T315I mutation CML. [ABSTRACT FROM AUTHOR]

The ubiquitin-proteasome pathway (UPP) regulates protein stability and normal cellular functions with the help of autocatalytic proteasome complex. Studies have linked aberrant proteasome activity to malignant cells and found that proteasome inhibitors play a significant role as therapeutic drugs for various types of cancer, specifically multiple myeloma and mantle cell lymphoma. Bortezomib, the first FDA-approved proteasome inhibitor for treating different stages of multiple myeloma, acts on cancer cells by inhibiting the 26S proteasome, modulating NF-κB, phosphorylating Bcl-2, upregulating of NOXA, blocking p53 degradation, activating caspase, generating reactive oxygen species (ROS), and inhibiting angiogenesis. However, its efficacy is limited due to side effects such as peripheral neuropathy (PN), thrombotic microangiopathy (TMA), and acute interstitial nephritis (AIN). Therefore, a better understanding of its precise mechanism of action may help mitigate these side effects. In this review, we have discussed the proposed mechanisms of action and off target effects of Bortezomib, along with the prospects of next generation potential proteasome inhibitor drugs in the treatment of cancer. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Cancer-related cognitive impairment in multiple myeloma patients significantly impacts their quality of life. • Bortezomib affects the central nervous system through yet unknown mechanisms. • Bortezomib could impair cognition by decreasing vascular endothelial growth factor (VEGF) • A PC-based psychodiagnostic test can be performed to access cognitive functions in multiple myeloma patients. Multiple myeloma is a chronic hematological malignancy that usually affects older adults. Cancer-related cognitive impairment in multiple myeloma patients significantly impacts the everyday quality of life, however its pathophysiology remains poorly understood. Bortezomib is a commonly used drug in the treatment of multiple myeloma that does not pass the blood–brain barrier. Nevertheless, it can still affect central nervous system (CNS) through yet unknown mechanisms. This article discusses the potential effect of bortezomib-based treatment on cognitive functions in multiple myeloma patients. We hypothesize that bortezomib impairs cognition by decreasing the levels of a neuroprotective cytokine – vascular endothelial growth factor (VEGF). The generation of hypotheses about the pathophysiology of cognitive impairment paves the way for future basic and clinical studies to improve multiple myeloma management. VEGF could serve as a biomarker of cognitive dysfunction while systematic evaluation of cognition could enable early detection of cognitive impairment. Timely recognition of cognitive impairment might be crucial when selecting the most appropriate treatment. Furthermore, this could allow the implementation of preventive measures against further deterioration in cognitive function and quality of life for patients with multiple myeloma. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hydroxyl functional allocation strategy was developed for cellulose based MIP. • Porous cellulose was used as both carrier and functional monomer for MIP. • Magnetic porous cellulose molecularly imprinted polymer (MPCMIP) was prepared. • B-MPCMIP has dual selectivity by boric acid affinity and molecular limitation. • The in vivo metabolism of bortezomib was studied by B-MPCMIP-UPLC-MS method. Bortezomib is widely recognized as an effective drug for the treatment of multiple myeloma, but its metabolism in vivo has not been reported. There are extremely high requirements for selectivity and enrichment ability of pretreatment methods due to the complex biological matrix and trace metabolites. Urgently, a novel magnetic porous cellulose molecularly imprinted polymers (B-MPCMIP) based on bortezomib was developed for the first time using the magnetic porous cellulose (MPC) as the both carrier and functional monomer by the hydroxyl functional allocation strategy of cellulose, which showed the dual selectivity towards bortezomib through the boric acid affinity and molecular structure limitation. Firstly, the cis dihydroxy groups of cellulose was occupied by phenylboronic acid; then, another hydroxyl group in cellulose was modified by silane reagent to introduce reaction site for grafting MIP; subsequently, the phenylboronic acid was removed to release the cis dihydroxy groups of cellulose as the functional monomer for MIP; finally, MIP was prepared on the surface of MPC with the MPC as the both carrier and functional monomer for obtaining B-MPCMIP, which can recognize the bortezomib through the boric acid affinity molecular structure limitation. A series of characterization studies showed that B-MPCMIP had a porous structure, good thermal stability, ultra-high magnetism, mesoporous structure, and superhydrophilicity. B-MPCMIP showed good adsorption capacity (Q max : 4.4 mg/g) and fast adsorption effect (adsorption equilibrium time: 30 min). Adsorption capacity of B-MPCMIP were also inspected under different temperature and pH conditions. The strong pH adsorption dependence indicates that B-MPCMIP mainly adsorbs bortezomib through the boric acid affinity, as the affinity between the cis dihydroxy groups in B-MPCMIP and the boric acid group in bortezomib is strongest at pH 8.5. Furthermore, B-MPCMIP exhibited excellent selectivity towards bortezomib with the imprinting factor, selectivity coefficient, and relative selectivity coefficient up to 8.6, 17, and 14, respectively. B-MPCMIP had outstanding reusability and stability, which remained 96 % of adsorption capacity after multiple recycling. B-MPCMIP-HPLC and B-MPCMIP-UPLC-MS/MS methods were successfully applied to enrich and detect bortezomib and its metabolites in mouse plasma and liver. The methods showed good selectivity, sensitivity, and accuracy. The maximum concentration of bortezomib in plasma and liver was detected as 34.3 μg/mL and 84.2 μg/mL. And six metabolites of bortezomib through oxidative deboronation were triumphantly detected and identified by B-MPCMIP-UPLC-MS/MS method. [ABSTRACT FROM AUTHOR]

• Replacement of bortezomib or carfilzomib with ixazomib in RRMM was investigated • Patients continued use of the same drugs, dose, and frequency of non-PI regimen components. • Ixazomib was well tolerated but not efficacious and was unable to overcome PI resistance. Identifying effective combination regimens is a high priority in multiple myeloma (MM), as most patients eventually become refractory to their current treatments. In this study, we investigated whether the proteasome inhibitor (PI) ixazomib could delay disease progression among patients who failed regimens containing another PI, bortezomib or carfilzomib. This phase 1/2, multicenter, open-label, nonrandomized study enrolled patients who were refractory to a previous regimen containing bortezomib or carfilzomib. Patients continued the other anti-MM drugs in the regimen at the same doses and frequencies. Patients with combination regimens with unknown maximum tolerated dose (MTD) of ixazomib were enrolled in phase 1, with ixazomib starting at 3 mg and then dose escalated to 4 mg. Patients on regimens with a known ixazomib MTD were enrolled in phase 2. Primary endpoints were overall response rate (ORR), clinical benefit rate (CBR), adverse events (AEs), and determination of maximum tolerated dose (MTD). Of the 46 patients enrolled, 39 were evaluable for efficacy. ORR and CBR were 12.8% and 17.9%, respectively. Ixazomib appeared to be well tolerated as a replacement for carfilzomib and bortezomib, with 23.9% of patients experiencing at least one grade ≥3 serious adverse event (SAE) and 37.0% experiencing at least one grade ≥3 AE. The most common grade ≥3 AEs were hyponatremia (8.7%), anemia (8.7%), dyspnea (8.7%), thrombocytopenia (6.5%), dehydration (4.3%), and pneumonia (4.3%). The results indicate that ixazomib is not an effective replacement for bortezomib or carfilzomib for patients with MM who have previously relapsed on other bortezomib/carfilzomib-containing regimens. [ABSTRACT FROM AUTHOR]

The effective treatment of glioma through conventional chemotherapy is proved to be a great challenge in clinics. The main reason is due to the existence of two physiological and pathological barriers respectively including the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) that prevent most of the chemotherapeutics from efficient delivery to the brain tumors. To address this challenge, an ideal drug delivery system would efficiently traverse the BBB and BBTB and deliver the therapeutics into the glioma cells with high selectivity. Herein, a targeted delivery system was developed based on nanostructured lipid carriers (NLCs) modified with two proteolytically stable D-peptides, D8 and RI-VAP (Dual NLCs). D8 possesses high affinity towards nicotine acetylcholine receptors (nAChRs), overexpressed on brain capillary endothelial cells (BCECs), and can penetrate through the BBB with high efficiency. RI-VAP is a specific ligand of cell surface GRP78 (csGRP78), a specific angiogenesis and cancer cell-surface marker, capable of circumventing the BBTB with superior glioma-homing property. Dual NLCs could internalize into BCECs, tumor neovascular endothelial cells, and glioma cells with high specificity and could penetrate through in vitro BBB and BBTB models with excellent efficiency compared to non-targeted or mono-targeted NLCs. In vivo whole-animal imaging and ex vivo imaging further confirmed the superior targeting capability of Dual NLCs towards intracranial glioma. When loaded with Bortezomib (BTZ), Dual NLCs attained the highest therapeutic efficiency by means of superior in vitro cytotoxicity and apoptosis and prolonged survival rate and efficient anti-glioma behavior in intracranial glioma bearing mice. Collectively, the designed targeting platform in this study could overcome multiple barriers and effectively deliver BTZ to glioma cells, which represent its potential for advanced brain cancer treatment with promising therapeutic outcomes. [Display omitted] • D8 and RI-VAP peptides can specifically bind to nAChRs and csGRP78, respectively. • D8 and RI-VAP-modified BTZ-loaded nanostructured lipid carriers were prepared to treat intracranial glioma. • Dual NLCs penetrated the BBB and BBTB and were distributed in the brain tumor. • Dual NLCs/BTZ prolonged the survival rate and improved the quality of life of glioma-bearing mice. • Dual NLCs/BTZ could be used as a promising tool for glioma treatment. [ABSTRACT FROM AUTHOR]

• Our patient had end-stage renal disease. • We performed desensitization and ABO-incompatible kidney transplantation. • Early anti-A/B antibody-mediated rejection occurred. • It was effectively treated with bortezomib and plasmapheresis. • No side effects were reported after bortezomib administration. ABO-incompatible kidney transplantation (KTP) is effective for avoiding transplantation-related issues. It is a viable alternative to ABO-compatible KTP, as both techniques have similar patient and graft survival rates. However, anti-A/B antibody-mediated rejection (AMR) can occur, resulting in poor long-term graft survival. A 45-year-old man with end-stage renal disease presented with a serum creatinine level of 10.2 mg/dL. We decided to perform KTP with spousal donation. He had panel-reactive antibody class I and II and cross matching test negativity, a 3/6 mismatch on human leukocyte antigen typing, an ABO antibody titer of 1:256, and no donor-specific antibodies. The patient and donor blood types were O+ and A+, respectively. The anti-A/B antibody titer was reduced preoperatively with rituximab (200 mg/body), plasmapheresis, and intravenous immunoglobulin (0.2 mg/kg). Basiliximab and methylprednisolone were used for induction immunosuppression, and tacrolimus, mycophenolate mofetil, and prednisolone were used for maintenance immunosuppression. KTP was successful, and graft function was initially normal. On postoperative day (POD) 5, the serum creatinine level and anti-A/B antibody titer increased from 0.9 mg/dL to 1.9 mg/dL and 1:16 to 1:64, respectively. Graft biopsy revealed acute AMR and tubular injury. We started steroid pulse therapy, plasmapheresis, and subcutaneous bortezomib (2.6 mg, twice a day, every 3 days) with no side effects. The serum creatinine level decreased from 5.7 mg/dL to 1.5 mg/dL on POD 28. Graft biopsy showed no rejection, and normal function was maintained for 40 months. Acute, early anti-A/B AMR was successfully treated with plasmapheresis and bortezomib. [ABSTRACT FROM AUTHOR]

The introduction of the proteasome inhibitor bortezomib into treatment regimens for myeloma has led to substantial improvement in patient survival. However, whilst bortezomib elicits initial responses in many myeloma patients, this haematological malignancy remains incurable due to the development of acquired bortezomib resistance. With other patients presenting with disease that is intrinsically bortezomib resistant, it is clear that new therapeutic approaches are desperately required to target bortezomib-resistant myeloma. We have previously shown that targeting sphingolipid metabolism with the sphingosine kinase 2 (SK2) inhibitor K145 in combination with bortezomib induces synergistic death of bortezomib-naïve myeloma. In the current study, we have demonstrated that targeting sphingolipid metabolism with K145 synergises with bortezomib and effectively resensitises bortezomib-resistant myeloma to this proteasome inhibitor. Notably, these effects were dependent on enhanced activation of the unfolded protein response, and were observed in numerous separate myeloma models that appear to have different mechanisms of bortezomib resistance, including a new bortezomib-resistant myeloma model we describe which possesses a clinically relevant proteasome mutation. Furthermore, K145 also displayed synergy with the next-generation proteasome inhibitor carfilzomib in bortezomib-resistant and carfilzomib-resistant myeloma cells. Together, these findings indicate that targeting sphingolipid metabolism via SK2 inhibition may be effective in combination with a broad spectrum of proteasome inhibitors in the proteasome inhibitor resistant setting, and is an approach worth clinical exploration. [ABSTRACT FROM AUTHOR]

Here, we report a case of living donor liver transplantation (LDLT) complicated with severe acute antibody-mediated rejection (aAMR), although desensitization was performed for preformed donor-specific anti-human leukocyte antigen antibody (DSA). LDLT was performed in a 59-year-old woman with alcoholic cirrhosis with a graft from her 60-year-old husband as a living donor. She had reproductive history of 4 gravidity and parity with her husband. Preoperative serologic studies showed positive complement-dependent cytotoxic crossmatch and anti-human leukocyte antigen-A26 antibody was identified as DSA. Desensitization for preformed DSA with rituximab and plasma exchange was performed before LDLT. We decided to perform LDLT using her husband right liver as living donor graft since the DSA mean fluoro-intensity was down to negative range. The immunosuppressive regimen was comprised with steroid and tacrolimus. However, the recipient developed acute cellular rejection on day 5 after LDLT, followed by severe aAMR. Re-administration of rituximab followed by 4 courses of plasma exchange failed to treat aAMR. The DSA mean fluoro-intensity was successfully suppressed after bortezomib was administered however impaired serologic liver function test and cholestasis were remained. The liver function test and cholestasis in the graft were improved after Everolimus was administered. The recipient was discharged on postoperative day 196. In conclusion, we report a case of LDLT who developed aAMR after desensitization of preformed DSA and was successfully treated with intensive therapy with bortezomib and everolimus. [ABSTRACT FROM AUTHOR]

Renal medullary carcinoma is a rare, aggressive neoplasm, and most patients succumb to their disease within months. Three patients were treated with a perioperative regimen consisting of platinum-based therapy, doxorubicin, and bortezomib. All achieved complete responses, 2 of which lasted for 12 months and the other in remission for 7 years. A multi-institution clinical trial of this regiment may be warranted. Background: Renal medullary carcinoma (RMC) is a very rare, aggressive neoplasm occurring almost exclusively in adolescents and young adults with sickle cell trait. Given the rare nature of this tumor, accounting for less than 0.5% of all renal carcinomas, most of the published data on therapies is from case reports and small case series, and current treatments are insufficient, with most patients succumbing to their disease in months. We report our experience with a cytotoxic chemotherapy regimen consisting of platinum-based therapy, doxorubicin, and bortezomib. Methods: Three patients with metastatic RMC at a single institution were treated off-label with a perioperative chemotherapy regimen for 4 cycles of 2 alternating regimens: regimen A consisting of cisplatin, doxorubicin, and bortezomib; regimen B consisting of carboplatin, paclitaxel, and gemcitabine. A radical nephrectomy was performed on all patients. Surveillance imaging was performed on all patients to assess response and disease burden. Patients received up to 12 months of maintenance therapy with everolimus. Results: Three Afr ican Amer ican patients - 2 males and 1 female aged 14, 28, and 31 - with sickle cell trait and metastatic disease were treated with this regimen. The median follow-up was 18 months. All had resection of the primary tumor - 2 patients after receiving neoadjuvant therapy, and one patient underwent resection prior to referral. All 3 patients achieved complete responses based on imaging, 2 of which lasted for 12 months, and another is still in remission over 7 years after diagnosis. Conclusions: This regimen of alternating cycles of platinum-based chemotherapy with bortezomib appeared to be active against RMC and was generally welltolerated. Given the extremely rare nature of this disease and dismal prognosis, new treatment modalities should be pursued, and whenever possible, patients should be enrolled in a clinical trial. We propose that a multiinstitution clinical trial of this regiment may be warranted. [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) is incurable and the second most common hematologic malignancy in plasma cells. Multiple myeloma stem cell-like cells (MMSCs), a rare population of MM cells, are believed to be the major cause of drug resistance and high recurrence rates in patients with MM. Therefore, developing novel strategies to eradicate MMSCs may favor myeloma treatment. In this study, based on the drug repositioning strategy, we found that albendazole (ABZ), a broad-spectrum antiparasitic drug, selectively suppresses the proliferation of multiple myeloma cells in vitro and in vivo and decreases number of aldehyde dehydrogenase (ALDH)-positive MMSCs in MM. Furthermore, RNA-seq of MM cells after ABZ treatment revealed that inhibition of the nuclear factor kappa-B (NF-κB) pathway is a key mediator of ABZ against MM. Moreover, we demonstrated that ABZ can resensitize cells resistant to bortezomib and overcome MMSCs-induced bortezomib resistance by decreasing ALDH1+ MMSCs numbers. Our findings provide preclinical evidence for utilizing the previously known pharmacologically active drug albendazole for the treatment of multiple myeloma. [ABSTRACT FROM AUTHOR]

Studies of the role of MYB in human malignancies have highlighted MYB as a potential drug target for acute myeloid leukemia (AML) and adenoid cystic carcinoma (ACC). Although transcription factors are often considered un-druggable, recent work has demonstrated successful targeting of MYB by low molecular weight compounds. This has fueled the notion that inhibition of MYB has potential as a therapeutic approach against MYB-driven malignancies. Here, we have used a MYB reporter cell line to screen a library of FDA-approved drugs for novel MYB inhibitors. We demonstrate that proteasome inhibitors have significant MYB-inhibitory activity, prompting us to characterize the proteasome inhibitor oprozomib in more detail. Oprozomib was shown to interfere with the ability of the co-activator p300 to stimulate MYB activity and to exert anti-proliferative effects on human AML and ACC cells. Overall, our work demonstrated suppression of oncogenic MYB activity as a novel result of proteasome inhibition. • Proteasome inhibitor oprozomib and related compounds are potent MYB-inhibitory agents. • Oprozomib induces differentiation and cell death in acute myeloid leukemia (AML) cells. • Oprozomib inhibits viability MYB/NFIB positive adenoid cystic carcinoma (ACC) cells. • Oprozomib inhibits MYB activity via co-activator p300. [ABSTRACT FROM AUTHOR]

Bortezomib is a key agent for treatment of cancer; while, it is a very hazardous bioactive substance (for healthy tissues). Therefore, delivering this drug to the targeted cancerous cells by using a suitable carrier is required. Considering it, in this project, several nanosized sorbents containing α-phographene, g-X 3 N 4 nanosheets, and C 19 X fullerenes have been considered for a systematic investigation on the possibility of adsorption and delivering of Bortezomib as a proteasome inhibitor drug residue. The results have indicated that g-B 3 N 4 could be considered as a potential actuator (a nano-sized key) which considerably alters its form by adsorbing Bortezomib (for example in lower temperatures) and returns to its early structure by losing this drug after receiving energy (in relatively higher temperatures). Also, the E ads of α-phographene-Bortezomib system is −9.14 kcal mol−1 which show like some other cases, it might be used for delivering of this drug. Finally, our results confirm that α-Phographene has a relatively good drug recovery time for desorption of Bortezomib (5.13(10−6) s at 298.15 K and 2.78(10−6) s at the body temperature). [Display omitted] • Among all considered sorbents, the best semiconductor sensor for detection of Bortezomib residue is g-C 3 N 4 which releases two strong and consecutive signals at −0.20761 eV, and − 0.90201 eV. • The α-phographene nanosheet could receive Bortezomib in a certain condition, and release this anti-cancer drug in another controlled situation. • The g-B 3 N 4 nano segment might be considered as a potential actuator (or nano-sized key) which significantly changes its shape by adsorbing BZB (especially in lower temperatures) and returns to its early structure by losing BZB after receiving energy (at higher temperatures). [ABSTRACT FROM AUTHOR]

Bortezomib is a proteasome inhibitor antineoplastic agent that was the first to be approved for cancer treatment. One of bortezomib's most prominent dose-limiting effects is nephrotoxicity; the underlying mechanism is believed to be oxidative stress. Chrysin is a compound found actively in honey and many plant species and stands out with its antioxidant properties. The present study aimed to determine the ameliorative effects of chrysin in bortezomib-induced nephrotoxicity. Thirty-five male Wistar rats were divided into control, BTZ, CHR, BTZ + CHR25, and BTZ + CHR50. Biochemical, molecular, Western blot, and histological methods analyzed renal function indicators, oxidative stress, endoplasmic reticulum stress, inflammation, apoptosis, and damage pathways. Chrysin decreased oxidative stress by reducing oxidants (MDA) and increasing antioxidants (SOD, CAT, Gpx, GSH, Nrf-2, HO-1, NQO1). Chrysin reduced endoplasmic reticulum stress by decreasing ATF-6, PERK, IRE1, and GRP-78 levels. Chrysin reduced inflammation damage by inhibiting the NF-κB pathway. Chrysin exhibited protective properties against apoptotic damage by decreasing Bax and Caspase-3 levels and increasing Bcl-2 levels. In addition, chrysin improved renal function and structural integrity and exhibited healing properties against toxic damage in tissue structure. Overall, chrysin exhibited an ameliorative effect against bortezomib-induced nephrotoxicity. [Display omitted] • Bortezomib induces nephrotoxicity. • Chrysin ameliorates Bortezomib-induced oxidative stress injury. • Chrysin reduced Bortezomib-induced inflammation. • Chrysin ameliorates Bortezomib-induced apoptotic injury. • Chrysin attenuates Bortezomib-induced endoplasmic reticulum stress. [ABSTRACT FROM AUTHOR]

Frailty in newly-diagnosed multiple myeloma (NDMM) patients is associated with treatment-related toxicity, which negatively affects health-related quality of life (HRQoL). Currently, data on changes in HRQoL of frail and intermediate-fit MM patients during active treatment and post-treatment follow-up are absent. The HOVON123 study (NTR4244) was a phase II trial in which NDMM patients ≥ 75 years were treated with nine dose-adjusted cycles of Melphalan-Prednisone-Bortezomib (MPV). Two HRQoL instruments (EORTC QLQ-C30 and -MY20) were obtained before start of treatment, after 3 and 9 months of treatment and 6 and 12 months after treatment for patients who did not yet start second-line treatment. HRQoL changes and/or differences in frail and intermediate-fit patients (IMWG frailty score) were reported only when both statistically significant (p < 0.005) and clinically relevant (>MID). 137 frail and 71 intermediate-fit patients were included in the analysis. Compliance was high and comparable in both groups. At baseline, frail patients reported lower global health status, lower physical functioning scores and more fatigue and pain compared to intermediate-fit patients. Both groups improved in global health status and future perspective; polyneuropathy complaints worsened over time. Frail patients improved over time in physical functioning, fatigue and pain. Improvement in global health status occurred earlier than in intermediate-fit patients. HRQoL improved during anti-myeloma treatment in both intermediate-fit and frail MM patients. In frail patients, improvement occurred faster and, in more domains, which was retained during follow-up. This implies that physicians should not withhold safe and effective therapies from frail patients in fear of HRQoL deterioration. • HRQoL differs between intermediate-fit & frail patients before start of MM therapy. • HRQoL improves in both intermediate-fit & frail patients during initial MM therapy. • Frail patients show faster & larger improvements in HRQoL during first treatment. • Improvements in HRQoL persist during post-treatment follow-up. • Physicians should not refrain from treating frail patients in fear of HRQoL loss. [ABSTRACT FROM AUTHOR]

• The surface receptors BCMA, TACI and BAFFR are shed by distinct mechanisms. • sBCMA and sTACI are biomarkers in certain B cell malignancies, autoimmunity and immunodeficiencies. • Inhibition of BCMA shedding may improve therapy of multiple myeloma. BAFF and APRIL regulate B cell homeostasis by binding to their three receptors BAFFR, BCMA and TACI. The complexity of this system is further increased by shedding of these three receptors; this reduces signaling due to the display of less surface receptors. Further, soluble forms, sBCMA and sTACI, were detected in body fluids and serve as biomarker in malignancies, autoimmune diseases and immunodeficiencies. sBCMA and sTACI function as decoys blocking BAFF and APRIL. BCMA is a promising therapeutic target in multiple myeloma, but sBCMA may reduce therapeutic activity of CAR T cells, bispecific antibodies, and antibody-drug conjugates. Insights into the biochemical mechanism of shedding of BCMA can be harnessed to improve BCMA-directed therapy by blocking its shedding with a γ-secretase inhibitor. [ABSTRACT FROM AUTHOR]

Hydrophobic drugs loaded nanogels were always associated with low encapsulation efficiency and immature burst release. In this work, dopamine grafted hyaluronate nanogels were designed for bortezomib (BTZ), a hydrophobic anticancer drug and a proteasome inhibitor. It was found that there was a more efficient loading and pH-controlled release of BTZ due to the presence of dopamine groups on the skeleton of the nanogels. The drug loading content (DLC) were up to 8.58% as the nanogels modified with 29% dopamine, compared to the DLC of less than 1% for nanogels without dopamine modification. It was the pH-sensitive nature of the borated bonds between BTZ and catechol groups that endowed the pH-responsive release behavior of BTZ in vitro. In vitro study proved good biocompatibility and efficient cell uptake of the nanogels. In vivo anti-tumor experiments demonstrated that bortezomib loading into the nanogel significantly enhanced the therapeutic effect of the drug. After 14-day treatment, the average tumor volume of BTZ loaded nanogel group was reduced by 200% more than that of free BTZ group. Combined with CD44 receptor targeting ability of hyaluronate and the merits of nanogel, the catechol modified hyaluronate nanogel exhibited as an efficient chemotherapeutic formulation of BTZ for cancer treatment. [ABSTRACT FROM AUTHOR]

Gallbladder cancer (GBC) is an aggressive malignancy of biliary tract with poor prognosis. Although several studies have shown the frequency of relevant genetic alterations, there are few genetic models or translational studies that really benefit for GBC treatment in the era of precision medicine. By targeted sequencing and immunohistochemistry staining, we identified that phosphate and tension homology deleted on chromosome ten (PTEN) was frequently altered in GBC specimens, and loss of PTEN expression was independently correlated with poor survival outcomes. Further drug screening assays revealed proteasome inhibitor bortezomib as a promising agent for GBC treatment, and knockdown of PTEN increased bortezomib efficacy both in vivo and in vitro. Therapeutic evaluation of patient derived xenografts (PDXs) strongly supported the utilization of bortezomib in PTEN deficient GBC. Mechanically, functional PTEN inhibited ARE-dependent transcriptional activity, the same machinery regulating the transcription of proteasome subunits, thus PTEN suppressed proteasome activity and bortezomib sensitivity. Through siRNA screening, we identified the ARE-related transcriptional suppressor BACH1 involved in PTEN-mediated proteasome inhibition and regulated by PTEN-AKT1 axis. In summary, our study indicates that proteasome activity represents a prime therapeutic target in PTEN-deficient GBC tumors, which is worthy of further clinical validation. [ABSTRACT FROM AUTHOR]

Proteasome inhibitors (PI) bortezomib or carfilzomib among them, play a crucial role in the modern standard therapy for multiple myeloma (MM). In this study, we intended to evaluate whether immunoproteasome (IMP) concentration could act as an effective biomarker which determines the probability of response to treatment with bortezomib, in order to detect groups of patients who are more likely to respond to treatment with PI. In our study, we evaluated IMP concentration in the plasma of 40 patients with monoclonal gammopathy of undetermined significance (MGUS) and 116 patients with newly diagnosed MM during treatment with or without PI. The values of all the studied parameters after the applied chemotherapy in the responders' group of patients declined considerably during the consecutive cycles of chemotherapy compared to their initial levels. On the contrary, in the group of non-responders, we observed no change in the measured IMP parameters during the consecutive cycles of therapy. We also showed that higher baseline IMP concentration might indicate longer overall survival (OS) in all patients. Our results indicate that assessing plasma IMP concentration can be applied as a strong biomarker for predicting clinical response to treatment and OS in patients with newly diagnosed MM. [ABSTRACT FROM AUTHOR]

Because of their many useful and unique properties, boronic acids are well suited for biomedical applications such as antitumor chemotherapy and boron neutron capture therapy (BNCT). Bortezomib, a boronic acid derivative, has drawn a lot of attention as a potent proteasome inhibitor. Nevertheless, because of rapid excretion and off-target effects, the clinical translation of boronic acid-containing drugs is limited. To this end, we employed a polymeric carrier to stably encapsulate boronic acid-containing drugs and achieve superior pharmacokinetics with an on-target drug release capability. Accordingly, to construct a supramolecular polymeric nanoparticle, we took advantage of the facile, stable, and pH-sensitive conjugation between boronic acids and diethanolamine-installed polymeric carriers. We demonstrated the feasibility of our molecular design by generating and applying bortezomib-loaded nanoparticles to a subcutaneous tumor-bearing mouse model. Stable encapsulation and pH-sensitive release of bortezomib facilitated antitumor efficacy and alleviated hepatotoxicity. We also verified the versatility of our approach through biological evaluations of the nanoparticles encapsulating benzo(b)thiophene-2-boronic acid, phenylboronic acid, and p-phenylene-diboronic acid. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Engagement between the natural killer group 2, member D (NKG2D) receptor and its ligands is one of the main mechanisms used by immune cells to target stressed cells for cell death. NKG2D ligands are known markers of cellular stress and are often upregulated on tumor cells. Certain drugs can further increase NKG2D ligand levels, thereby making tumor cells more susceptible to immune cell detection and destruction. However, the effectiveness of this approach appears to be limited with drug treatment alone, possibly due to immune dysregulation in the setting of malignancies. We hypothesized that a more effective approach would be a combination of NKG2D ligand-inducing drugs, such as the proteasome inhibitor bortezomib, and ex vivo -expanded peripheral blood γδ T cells (i.e., Vγ9Vδ2 T cells). Acute myeloid leukemia (AML) is a high-risk hematologic malignancy, and treatment has shown limited benefit with the addition of bortezomib to standard chemotherapy regimens. Two AML cells lines, Nomo-1 and Kasumi-1, were treated with increasing concentrations of bortezomib, and changes in NKG2D ligand expression were measured. Bortezomib treatment significantly increased expression of the NKG2D ligand UL16 binding protein (ULBP) 2/5/6 in both cell lines. Vγ9Vδ2 T cells were expanded and isolated from peripheral blood of healthy donors to generate a final cellular product with a mean of 96% CD3+/γδ T-cell receptor-positive cells. Combination treatment of the AML cell lines with γδ T cells and bortezomib resulted in significantly greater cytotoxicity than γδ T cells alone, even at lower effector-to-target ratios. Based on the positive results against AML and the generalizable mechanism of this combination approach, it was also tested against T-cell acute lymphoblastic leukemia (T-ALL), another high-risk leukemia. Similarly, bortezomib increased ULBP 2/5/6 expression in T-ALL cell lines, Jurkat and MOLT-4 and improved the cytotoxicity of γδ T cells against each line. Collectively, these results show that bortezomib enhances γδ T-cell-mediated killing of both AML and T-ALL cells in part through increased NKG2D ligand-receptor interaction. Furthermore, proof-of-concept for the combination of ex vivo -expanded γδ T cells with stress ligand-inducing drugs as a therapeutic platform for high-risk leukemias is demonstrated. [ABSTRACT FROM AUTHOR]

• Molecular response to chemo-, radio- and radionuclide therapy was assessed in NENs. • Cisplatin and PRRT triggered DNA damage repair-related gene expression. • Bortezomib inhibited DNA damage repair related gene expression. • Combined therapy resulted in short-term pro-apoptotic effects in vitro. • Tumoral heterogeneity interfered with long-term sensitization assessment in vivo. Background: Well-differentiated gastroenteropancreatic neuroendocrine neoplasms are rare tumors with a slow proliferation. They are virtually resistant to many DNA-damaging therapeutic approaches, such as chemo- and external beam therapy, which might be overcome by DNA damage inhibition induced by proteasome inhibitors such as bortezomib. Methods and results: In this study, we assessed several combined treatment modalities in vitro and in vivo. By cell-based functional analyses, in a 3D in ovo and an orthotopic mouse model, we demonstrated sensitizing effects of bortezomib combined with cisplatin, radiation and peptide receptor radionuclide therapy (PRRT). By gene expression profiling and western blot, we explored the underlying mechanisms, which resulted in an impaired DNA damage repair. Therapy-induced DNA damage triggered extrinsic proapoptotic signaling as well as the induction of cell cycle arrest, leading to a decreased vital tumor volume and altered tissue composition shown by magnetic resonance imaging and F-18-FDG-PET in vivo , however with no significant additional benefit related to PRRT alone. Conclusions: We demonstrated that bortezomib has short-term sensitizing effects when combined with DNA damaging therapy by interfering with DNA repair in vitro and in ovo. Nevertheless, due to high tumor heterogeneity after PRRT in long-term observations, we were not able to prove a therapeutic advantage of bortezomib-combined PRRT in an in vivo mouse model. [ABSTRACT FROM AUTHOR]

Background: Improved therapeutic options are needed for patients with relapsed or relapsed and refractory multiple myeloma. Subcutaneous bortezomib has replaced intravenous bortezomib as it is associated with a more favourable toxicity profile. We investigated the activity and safety of three different dosing regimens of oral panobinostat in combination with subcutaneous bortezomib and oral dexamethasone for this indication.Methods: PANORAMA 3 is an open-label, randomised, phase 2 study being done at 71 sites (hospitals and medical centres) across 21 countries. Patients aged 18 years or older with relapsed or relapsed and refractory multiple myeloma (as per International Myeloma Working Group 2014 criteria), who had received one to four previous lines of therapy (including an immunomodulatory agent), and had an Eastern Cooperative Oncology Group performance status of 2 or lower, were randomly assigned (1:1:1) to receive oral panobinostat 20 mg three times weekly, 20 mg twice weekly, or 10 mg three times weekly, plus subcutaneous bortezomib and oral dexamethasone. All study drugs were administered in 21-day cycles. Randomisation was done by an interactive response technology provider, and stratified by number of previous treatment lines and age. The primary endpoint was overall response rate after up to eight treatment cycles (analysed in all randomly assigned patients by intention to treat). Safety analyses included all patients who received at least one dose of any study drug. No statistical comparisons between groups were planned. This trial is ongoing and registered with ClinicalTrials.gov, NCT02654990.Findings: Between April 27, 2016, and Jan 17, 2019, 248 patients were randomly assigned (82 to panobinostat 20 mg three times weekly, 83 to panobinostat 20 mg twice weekly, and 83 to 10 mg panobinostat three times weekly). Median duration of follow-up across all treatment groups was 14·7 months (IQR 7·8-24·1). The overall response rate after up to eight treatment cycles was 62·2% (95% CI 50·8-72·7; 51 of 82 patients) for the 20 mg three times weekly group, 65·1% (53·8-75·2; 54 of 83 patients) for the 20 mg twice weekly group, and 50·6% (39·4-61·8; 42 of 83 patients) for the 10 mg three times weekly group. Grade 3-4 adverse events occurred in 71 (91%) of 78 patients in the 20 mg three times weekly group, 69 (83%) of 83 patients in the 20 mg twice weekly group, and 60 (75%) of 80 patients in the 10 mg three times weekly group; the most common (≥20% patients in any group) grade 3-4 adverse events were thrombocytopenia (33 [42%] of 78, 26 [31%] of 83, and 19 [24%] of 83 patients) and neutropenia (18 [23%], 13 [16%], and six [8%]). Serious adverse events occurred in 42 (54%) of 78 patients in the 20 mg three times weekly group, 40 (48%) of 83 patients in the 20 mg twice weekly group, and 35 (44%) of 83 patients in the 10 mg three times weekly group; the most common serious adverse event (≥10% patients in any group) was pneumonia (nine [12%] of 78, ten [12%] of 83, and nine [11%] of 80 patients). There were 14 deaths during the study (five [6%] of 78 patients in the 20 mg three times weekly group, three [4%] of 83 in the 20 mg twice weekly group, and six [8%] of 80 in the 10 mg three times weekly group); none of these deaths was deemed treatment related.Interpretation: The safety profile of panobinostat 20 mg three times weekly was more favourable than in previous trials of this regimen with intravenous bortezomib, suggesting that subcutaneous bortezomib improves the tolerability of the panobinostat plus bortezomib plus dexamethasone regimen. The overall response rate was highest in the 20 mg three times weekly and 20 mg twice weekly groups, with 10 mg three times weekly best tolerated.Funding: Novartis Pharmaceuticals and Secura Bio. [ABSTRACT FROM AUTHOR]

Ras-GTPase activating protein SH3-domain-binding proteins (G3BP) are a small family of RNA-binding proteins implicated in regulating gene expression. Changes in expression of G3BPs are correlated to several cancers including thyroid, colon, pancreatic and breast cancer. G3BPs are important regulators of stress granule (SG) formation and function. SG are ribonucleoprotein (RNP) particles that respond to cellular stresses to triage mRNA resulting in transcripts being selectively degraded, stored or translated resulting in a change of gene expression which confers a survival response to the cell. These changes in gene expression contribute to the development of drug resistance. Many RNA viruses, including Chikungunya (and potentially Coronavirus), dismantle SG so that the cell cannot respond to the viral infection. Non-structural protein 3 (nsP3), from the Chikungunya virus, has been shown to translocate G3BP away from SG. Interestingly in cancer cells, the formation of SG is correlated to drug-resistance and blocking SG formation has been shown to reestablish the efficacy of the anticancer drug bortezomib. Chikungunya nsP3 was transfected into breast cancer cell lines T47D and MCF7 to disrupt SG formation. Changes in the cytotoxicity of bortezomib were measured. Bortezomib cytotoxicity in breast cancer cell lines changed with a 22 fold decrease in its IC 50 for T47D and a 7 fold decrease for MCF7 cells. Chikungunya nsP3 disrupts SG formation. As a result, it increases the cytotoxicity of the FDA approved drug, bortezomib. In addition, the increased cytotoxicity appears to correlate to improved bortezomib selectivity when compared to control cell lines. [ABSTRACT FROM AUTHOR]

The solubility of bortezomib, a boronic acid, in water and normal saline is often misquoted in the literature. Here we confirm that bortezomib equilibrium solubility in water and normal saline is 0.59 ± 0.07 and 0.52 ± 0.11 mg/mL, respectively. The aqueous solubility is significantly enhanced, 1.92 ± 0.14 and 3.40 ± 0.21 mg/mL, respectively, in the presence of 55 mM and 137 mM D-mannitol in normal saline, as in the commercial formulation, Velcade®, after reconstitution. This is due to reversible ester formation between bortezomib and D-mannitol. Based on the pH-solubility profile curve for bortezomib in the absence of added D-mannitol, bortezomib's pKa value is estimated to be 8.8 ± 0.2. Boric acid, glycine and a combination of the two, used in an alternative formulation to that of Velcade® do not enhance the equilibrium aqueous solubility of bortezomib. [ABSTRACT FROM AUTHOR]

We previously found that the partially purified 30–100 kDa fraction of areca-nut-extract (ANE 30–100K) induces autophagy in different types of cells including oral carcinoma OECM-1 cells. This study was to analyze the composition and possible mechanisms of ANE 30-100K-induced autophagy (AIA). Phenol-sulfuric acid method and high performance anion exchange chromatography were utilized to analyze the composition of ANE 30–100K. OECM-1 and esophageal CE81T/VGH cells were taken as the experimental models. Microscope and transmission electron microscope were used to observe morphological changes. Cell viability and specific proteins were respectively measured by XTT and Western bot assay. shRNA and chemical inhibitors were applied to assess the involvement of Atg5, caveolin, and proteasome in AIA. ANE 30–100K contains ∼67% carbohydrate, which is composed of fucose (5.938%), arabinose (24.631%), glucosamine (8.066%), galactose (26.820%), glucose (21.388%), and mannose (13.157%). After ANE 30–100K stimulation, CE81T/VGH cells showed intracellular vacuoles, acidic vesicles, double-membrane vacuoles, and elevated LC3-II level. ANE 30-100K-induced cytotoxicity and LC3-II accumulation were significantly inhibited by Atg5 knockdown. Furthermore, the endocytosis inhibitor (methyl-β-cyclodextrin) and two caveolin shRNAs, as well as two proteasome inhibitors (lactacystin and epoxomicin), were shown to significantly attenuate ANE 30-100K-induced cytotoxicity and LC3-II accumulation in both OECM-1 and CE81T/VGH cells. The major components of ANE 30–100K are carbohydrates. CE81T/VGH also exhibited autophagic responses to ANE 30–100K. Caveolin-mediated endocytosis and proteasome are involved in AIA. This study may have provided new knowledges of the action mechanisms and compositions of ANE 30–100K. [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) cells have high rates of secretion of proteins rich in disulfide bonds and depend upon compartmentalized redox balance for accurate protein folding. The proteasome inhibitor bortezomib (Btz) is a successful frontline treatment for the disease, but its long-term efficacy is restricted by the acquisition of resistance. We found that MM cell lines resistant to Btz maintain high levels of oxidative stress and are cross resistant to endoplasmic reticulum (ER) stress-inducing agents thapsigargin (ThG), and tunicamycin (TuM). Moreover, cells expressing high/wild type levels of glutathione S-transferase P (GSTP) are more resistant than Gstp1/p2 knockout cells. In agreement, basal levels of S-glutathionylated proteins and redox regulation enzymes, including GSTP are elevated at mRNA and protein levels in resistant cells. GSTP mediated S-glutathionylation (SSG) regulates the activities of a number of redox active ER proteins. Here we demonstrated that the post-translational modification determines the balance between foldase and ATPase activities of the binding immunoglobulin protein (BiP), with Cys41-SSG important for ATPase, and Cys420-SSG for foldase. BiP expression and S-glutathionylation are increased in clinical specimens of bone marrow from MM patients compared to non-cancerous samples. Preventing S-glutathionylation in MM cells with a GSTP specific inhibitor restored BiP activities and reversed resistance to Btz. Therefore, S-glutathionylation of BiP confers pro-survival advantages and represents a novel mechanism of drug resistance in MM cells. We conclude that altered GSTP expression leads to S-glutathionylation of BiP, and contributes to acquired resistance to Btz in MM. Image 1 [ABSTRACT FROM AUTHOR]

Background: Bortezomib, lenalidomide, and dexamethasone (VRd) is a standard therapy for newly diagnosed multiple myeloma. Carfilzomib, a next-generation proteasome inhibitor, in combination with lenalidomide and dexamethasone (KRd), has shown promising efficacy in phase 2 trials and might improve outcomes compared with VRd. We aimed to assess whether the KRd regimen is superior to the VRd regimen in the treatment of newly diagnosed multiple myeloma in patients who were not being considered for immediate autologous stem-cell transplantation (ASCT).Methods: In this multicentre, open-label, phase 3, randomised controlled trial (the ENDURANCE trial; E1A11), we recruited patients aged 18 years or older with newly diagnosed multiple myeloma who were ineligible for, or did not intend to have, immediate ASCT. Participants were recruited from 272 community oncology practices or academic medical centres in the USA. Key inclusion criteria were the absence of high-risk multiple myeloma and an Eastern Cooperative Oncology Group performance status of 0-2. Enrolled patients were randomly assigned (1:1) centrally by use of permuted blocks to receive induction therapy with either the VRd regimen or the KRd regimen for 36 weeks. Patients who completed induction therapy were then randomly assigned (1:1) a second time to either indefinite maintenance or 2 years of maintenance with lenalidomide. Randomisation was stratified by intent for ASCT at disease progression for the first randomisation and by the induction therapy received for the second randomisation. Allocation was not masked to investigators or patients. For 12 cycles of 3 weeks, patients in the VRd group received 1·3 mg/m2 of bortezomib subcutaneously or intravenously on days 1, 4, 8, and 11 of cycles 1-8, and day 1 and day 8 of cycles nine to twelve, 25 mg of oral lenalidomide on days 1-14, and 20 mg of oral dexamethasone on days 1, 2, 4, 5, 8, 9, 11, and 12. For nine cycles of 4 weeks, patients in the KRd group received 36 mg/m2 of intravenous carfilzomib on days 1, 2, 8, 9, 15, and 16, 25 mg of oral lenalidomide on days 1-21, and 40 mg of oral dexamethasone on days 1, 8, 15, and 22. The coprimary endpoints were progression-free survival in the induction phase, and overall survival in the maintenance phase. The primary analysis was done in the intention-to-treat population and safety was assessed in patients who received at least one dose of their assigned treatment. The trial is registered with ClinicalTrials.gov, NCT01863550. Study recruitment is complete, and follow-up of the maintenance phase is ongoing.Findings: Between Dec 6, 2013, and Feb 6, 2019, 1087 patients were enrolled and randomly assigned to either the VRd regimen (n=542) or the KRd regimen (n=545). At a median follow-up of 9 months (IQR 5-23), at a second planned interim analysis, the median progression-free survival was 34·6 months (95% CI 28·8-37·8) in the KRd group and 34·4 months (30·1-not estimable) in the VRd group (hazard ratio [HR] 1·04, 95% CI 0·83-1·31; p=0·74). Median overall survival has not been reached in either group. The most common grade 3-4 treatment-related non-haematological adverse events included fatigue (34 [6%] of 527 patients in the VRd group vs 29 [6%] of 526 in the KRd group), hyperglycaemia (23 [4%] vs 34 [6%]), diarrhoea (23 [5%] vs 16 [3%]), peripheral neuropathy (44 [8%] vs four [<1%]), dyspnoea (nine [2%] vs 38 [7%]), and thromboembolic events (11 [2%] vs 26 [5%]). Treatment-related deaths occurred in two patients (<1%) in the VRd group (one cardiotoxicity and one secondary cancer) and 11 (2%) in the KRd group (four cardiotoxicity, two acute kidney failure, one liver toxicity, two respiratory failure, one thromboembolic event, and one sudden death).Interpretation: The KRd regimen did not improve progression-free survival compared with the VRd regimen in patients with newly diagnosed multiple myeloma, and had more toxicity. The VRd triplet regimen remains the standard of care for induction therapy for patients with standard-risk and intermediate-risk newly diagnosed multiple myeloma, and is a suitable treatment backbone for the development of combinations of four drugs.Funding: US National Institutes of Health, National Cancer Institute, and Amgen. [ABSTRACT FROM AUTHOR]

Overexpression of Myristoylated Alanine-Rich C Kinase Substrate (MARCKS) is implicated in drug resistance and progression of multiple myeloma (MM). The basis for MARCKS induction and impact on MM are not known. Here we show that microRNA-34a (miR-34a), regulates MARCKS translation and is under-expressed in drug-resistant MM cells, leading to increased MARCKS protein level. Over-expression of miR-34a reduces MARCKS expression and sensitizes resistant cells to anti-myeloma drugs. A MARCKS peptide inhibitor (MPS) exerts a dose dependent cytotoxic effect on drug-resistant MM cells with minimal cytotoxicity to normal hematopoietic cells. MPS synergizes with the proteasomal-inhibitor bortezomib to effectively kill drug-resistant MM cells both in vitro and in a xenograft model of MM. While MARCKS inhibition killed MM cells, it also enhanced a pro-survival autophagic pathway that sustained growth following MARCKS inhibition. In accordance, combined treatment with MARCKS antagonists, bortezomib and the autophagy inhibitor, chloroquine, significantly diminished tumor growth in drug-resistant MM cell lines as well as primary MM cells. This study uncovers a mechanism of drug resistance involving miR-34a-MARCKS autoregulatory loop and provides a framework for a potentially new therapeutic strategy to overcome drug resistance in multiple myeloma. [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) is an incurable hematological malignancy, for which novel effective therapies are urgently needed. We synthesized a novel phosphoramide compound, DCZ0847, showing a potent anti-myeloma activity both in vitro and in vivo. DCZ0847 showed high cytotoxicity towards primary MM cells but had no effect on normal cells and was well tolerated in vivo. The anti-myeloma activity of DCZ0847 was associated with inhibition of cell proliferation; promotion of cell apoptosis via mitochondrial transmembrane potential collapse and caspase-mediated extrinsic or intrinsic apoptotic pathways; and the induction of G2/M phase arrest via downregulation of CDC25C, CDK1, and cyclin B1. In particular, DCZ0847 induced DNA damage and triggered a DNA-damage response by enhancing the levels of γ-H2A.X, phosphorylated (p)-ATM, p-ATR, p-Chk1, and p-Chk2. Additionally, DCZ0847 was able to overcome the bone marrow stromal cells-induced proliferation of MM cells and blocked JAK2/STAT3 signaling. Importantly, DCZ0847 acted synergistically with bortezomib, with the combination exerting greater cytotoxic effects in vitro and in vivo. Together, our results indicate that DCZ0847, alone or in combination with bortezomib, may represent a potential new therapy for patients with MM. [ABSTRACT FROM AUTHOR]