Engineering c-Met-CAR NK-92 cells as a promising therapeutic candidate for lung adenocarcinoma.

Mesenchymal-epithelial transition factor (C-Met) has been acknowledged as a significant therapeutic target for treating lung adenocarcinoma (LUAD). However, the potential application of chimeric antigen receptors (CAR)-modified natural killer (NK) cells targeting c-Met in LUAD is rarely explored. In this study, bioinformatic databases were searched and a tissue microarray (TMA) was enrolled to investigate expression status and prognostic role of c-Met in LUAD. Then, four types of c-Met-CAR structures were designed and prepared. The engineering CAR-NK cells containing c-Met-CARs were transfected, verified and characterized. The tumor-inhibitory role of c-Met-CAR-NK cells was finally evaluated in vitro and in vivo. The results demonstrated that c-Met expression elevated and confirmed that high c-Met expression was significantly associated with unfavorable prognosis in LUAD. Then, C-Met-CAR-NK cells were successfully constructed and DAP10 designed in CAR structure was a favorable stimulator for NK cell activation. CCN4 containing DAP10 co-stimulator exhibited the strongest cytotoxicity compared with other CAR-NK cells. Furthermore, CCN4 cells also exerted the prominent tumor-inhibitory effect on xenograft tumor growth. Collectively, this study suggests that DAP10 is a potent stimulator in CAR structure for NK cell activation, and CCN4-based immunotherapy may represent a promising strategy for the treatment of c-Met-positive LUAD.

Transcription factor p8 regulates autophagy in response to disulfiram via PI3K/mTOR/p70S6K signaling pathway in pancreatic cancer cells.

Disulfiram (DSF), which is an inhibitor of aldehyde dehydrogenase (ALDH) and approved by the FDA for the treatment of alcoholism previously, has been repurposed for use as a cancer treatment because of its potent effect in preclinical studies. In this study, we found that disulfiram forms potent complexes with copper (DSF/Cu) inhibited cell proliferation, induced apoptosis in human pancreatic cancer cells, which was detected by flow cytometry and western blotting. Meanwhile, autophagy and autophagic flux also clearly observed by transmission electron microscopy, confocal microscopy and flow cytometry. Our results also showed that DSF/Cu induced transcription factor p8 upregulation and PI3K/mTOR signaling pathway activation detected by real-time PCR and western blotting. Additionally, suppression of p8 inactivated the mTOR signaling pathway and autophagic flux maintained. Furthermore, mechanism study indicated that autophagy induced by DSF/Cu was regulated by p8 and was related to PI3K/mTOR/p70S6K signaling pathway in pancreatic cancer cells. Our findings provide insights into the role of p8 in regulating autophagy induced by DSF/Cu effects in pancreatic cancer cells.

A novel immune checkpoint siglec-15 antibody inhibits LUAD by modulating mφ polarization in TME.

BACKGROUND: Siglec-15 (S15) is a type-I transmembrane protein and is considered a new candidate of immune checkpoint inhibitor for cancer immunotherapy. METHODS: In the present study, we first constructed and characterized a chimeric S15-specific monoclonal antibody (S15-4E6A). Then, the antitumor effectiveness and modulatory role of S15-4E6A in macrophages (mφs) were explored in vitro and in vivo. Finally, the underlying mechanism by which S15mAb inhibits LUAD was preliminarily explored. RESULTS: The results demonstrated the successful construction of S15-4E6A, and S15-4E6A exerted an efficacious tumor-inhibitory effect on LUAD cells and xenografts. S15-4E6A could promote M1-mφ polarization while inhibiting M2-mφ polarization, both in vitro and in vivo. CONCLUSIONS: S15-based immunotherapy that functions by modulating mφ polarization may be a promising strategy for the treatment of S15-positive LUAD.

TROP2 Down-regulated DSG2 to Promote Gastric Cancer Cell Invasion and Migration by EGFR/AKT and DSG2/PG/ß-Catenin Pathways.

BACKGROUND: Gastric cancer (GC) is the fourth most commonly found cancer and the second- highest cause of cancer-related death worldwide. TROP2 overexpression is closely related to many cancers, including gastrointestinal tumors. DSG2 is an important protein in cell adhesion, and its loss affects cell migration. AIMS AND OBJECTIVE: This study aimed to explore the specific mechanism of TROP2 in promoting gastric cancer and provide a basis for the prevention and treatment of gastric cancer. METHOD: DSG2 was identified as an interacting protein of TROP2 in GC cells by coimmunoprecipitation and mass spectrometry. The regulated behavior of TROP2 on DSG2 expression was investigated with TROP2 over-expressure or knockdown. Cell-cell adhesion capacity mediated by DSG2 was evaluated by adhesion-related assays. Electron microscope observation was made for accessing GC tumor desmosome assembly. Proteins in EGFR/AKT and DSG2/PG/ß-catenin pathways were evaluated by western blotting. RESULT: This study suggests that abundant expression of TROP2 in GC cells lessened DSG2 levels as well as desmosome adhesion, increased cell invasion and migration, and promoted malignant progression through EGFR/AKT and DSG2/PG/ß-catenin pathways. CONCLUSION: TROP2 promotes cell invasion and migration in gastric cancer by decreasing DSG2 expression through EGFR/AKT and DSG2/PG/ß-catenin pathways.

A SARS-CoV-2 neutralizing antibody discovery by single cell sequencing and molecular modeling.

Although vaccines have been developed, mutations of SARS-CoV-2, especially the dominant B.1.617.2 (delta) and B.1.529 (omicron) strains with more than 30 mutations on their spike protein, have caused a significant decline in prophylaxis, calling for the need for drug improvement. Antibodies are drugs preferentially used in infectious diseases and are easy to get from immunized organisms. The current study combined molecular modeling and single memory B cell sequencing to assess candidate sequences before experiments, providing a strategy for the fabrication of SARS-CoV-2 neutralizing antibodies. A total of 128 sequences were obtained after sequencing 196 memory B cells, and 42 sequences were left after merging extremely similar ones and discarding incomplete ones, followed by homology modeling of the antibody variable region. Thirteen candidate sequences were expressed, of which three were tested positive for receptor binding domain recognition but only one was confirmed as having broad neutralization against several SARS-CoV-2 variants. The current study successfully obtained a SARS-CoV-2 antibody with broad neutralizing abilities and provided a strategy for antibody development in emerging infectious diseases using single memory B cell BCR sequencing and computer assistance in antibody fabrication.

Proteasome Subunit Alpha Type 7 Promotes Proliferation and Metastasis of Gastric Cancer Through MAPK Signaling Pathway.

BACKGROUND: Proteasome subunit alpha type 7 (PSMA7) shows a carcinogenic effect on various human malignancies, but its role and regulatory mechanism in gastric carcinoma (GC) remain unclear. AIMS: This study aimed to explore the role and mechanism of PSMA7 in GC. METHODS: In this study, PSMA7 expressions in GC cells and tissues were detected, and relationships between PSMA7 and clinicopathological features were explored. Then, PSMA7 levels in human GC cells were intervened, and changes in cell biological behavior were observed in vitro and vivo. Key proteins and downstream factors of MAPK signaling pathway were detected after PSMA7 intervention. RESULTS: PSMA7 was upregulated in GC tissues and cell lines. PSMA7 overexpression was significantly associated with poor pTNM, cTNM stage, and high HP infection. PSMA7 can promote proliferation, invasion, and metastasis of GC cells in vitro and vivo. Furthermore, PSMA7 expression affected the phosphorylation level of JNK, P38, ERK and the expressions of their downstream factors Ap-1, c-myc, P53. CONCLUSION: PSMA7 can promote GC proliferation, invasion, and metastasis through MAPK signaling pathway in GC cells.

Bispecific c-Met/PD-L1 CAR-T Cells Have Enhanced Therapeutic Effects on Hepatocellular Carcinoma.

T cells expressing chimeric antigen receptors, especially CD19 CAR-T cells have exhibited effective antitumor activities in B cell malignancies, but due to several factors such as antigen escape effects and tumor microenvironment, their curative potential in hepatocellular carcinoma has not been encouraging. To reduce the antigen escape risk of hepatocellular carcinoma, this study was to design and construct a bispecific CAR targeting c-Met and PD-L1. c-Met/PD-L1 CAR-T cells were obtained by lentiviral transfection, and the transfection efficiency was monitored by flow cytometry analysis. LDH release assays were used to elucidate the efficacy of c-Met/PD-L1 CAR-T cells on hepatocellular carcinoma cells. In addition, xenograft models bearing human hepatocellular carcinoma were constructed to detect the antitumor effect of c-Met/PD-L1 CAR-T cells in vivo. The results shown that this bispecific CAR was manufactured successfully, T cells modified with this bispecific CAR demonstrated improved antitumor activities against c-Met and PD-L1 positive hepatocellular carcinoma cells when compared with those of monovalent c-Met CAR-T cells or PD-L1 CAR-T cells but shown no distinct cytotoxicity on hepatocytes in vitro. In vivo experiments shown that c-Met/PD-L1 CAR-T cells significantly inhibited tumor growth and improve survival persistence compared with other groups. These results suggested that the design of single-chain, bi-specific c-Met/PD-L1 CAR-T is more effective than that of monovalent c-Met CAR-T for the treatment of hepatocellular carcinoma., and this bi-specific c-Met/PD-L1 CAR is rational and implementable with current T-cell engineering technology.

Exosomal miR-222 from adriamycin-resistant MCF-7 breast cancer cells promote macrophages M2 polarization via PTEN/Akt to induce tumor progression.

Exosome-mediated intercellular communication is considered to be an effective mode for malignant cells to transform biological behaviors in stromal cells. However, the mechanisms by which exosomes modulate macrophages within tumor microenvironment remain largely unclear. In this study, we found that both adriamycin-resistant breast cancer (BCa) cells and the corresponding exosomes (A/exo) were capable of inducing macrophages M2 polarization, which promoted the mobility, proliferation, migration and invasion of BCa cells. Since exosomes deliver microRNAs to affect cellular functions in recipient cells, we confirmed that miR-222 was significantly enriched in A/exo and could be successfully transferred to macrophages. Increased miR-222 level was also detected in exosomes derived from plasma and tissues of chemoresistant patients. Moreover, exosomal miR-222 from A/exo polarized M2 macrophages by targeting PTEN and activating Akt signaling pathway, which promoted BCa cells progression in a feed back loop. Co-culture of adriamycin-resistant BCa cells with macrophages in which miR-222 was upregulated or treated with A/exo facilitated tumor growth in vivo. Collectively, our data demonstrated that chemoresistant BCa cells could remodel macrophages within tumor microenvironment by secreting exosomal miR-222, which directly targeted PTEN and caused Akt cascade activation and macrophages M2 polarization. Our findings may provide a foundation for a promising strategy of BCa treatment by targeting exosomes or exosomal miR-222.

Long non-coding RNA linc00665 inhibits CDKN1C expression by binding to EZH2 and affects cisplatin sensitivity of NSCLC cells.

Long non-coding RNAs (lncRNAs) can play significant regulatory roles in cells that affect the development and acquired drug resistance of lung cancer. Herein, we report that lncRNA linc00665 is significantly upregulated in non-small cell lung cancer (NSCLC) tissues compared with adjacent normal tissues. linc00665 affects the sensitivity of NSCLC cells to the chemotherapy drug cisplatin (DDP), making it a potential target for the treatment of NSCLC. Functional experiments showed that linc00665 enhanced the proliferation and migration of NSCLC cells in vivo and in vitro, and knocking down linc00665 could enhance the drug sensitivity of NSCLC cells to DDP. Further work revealed that linc00665 could recruit enhancer of zeste homolog 2 (EZH2) to the promoter region of cyclin-dependent kinase inhibitor 1C (CDKN1C) to inhibit its transcription and thus carry out its tumorigenic role. In conclusion, our study elucidated the carcinogenic role of the linc00665-EZH2-CDKN1C axis in NSCLC tumors and its ability to influence the sensitivity of these tumors to DDP. These results suggest that linc00665 may be a potential diagnostic marker and therapeutic target in NSCLC, and they also provide a new direction for the development of clinical reversal methods for acquired drug resistance in patients with NSCLC.

Combination Therapy with iRGD-antiCD3 and PD-1 Blockade Enhances Antitumor Potency of Cord Blood-Derived T Cells.

BACKGROUND: T cell-redirecting bispecific antibodies (BsAbs) are emerging as a potent cancer therapy that crosslinks tumor cells and T cells by simultaneously binding to tumor-associated antigen and CD3ε. However, immune inhibitory molecules can be remarkably upregulated after BsAbs treatment, leading to a suppressive tumor microenvironment and treatment resistance. This can be partially reversed by combination with immune checkpoint inhibitors. In our previous work, we successfully constructed the recombinant protein iRGD-antiCD3 and demonstrated that it promoted antitumor efficacy of transferred T cells by promoting T cell activation and infiltration. METHODS: We detected the levels of both PD-1 and PD-L1 as resistance to iRGD-antiCD3 treatment. Using cord blood-derived T cells, we assessed the activation and effects of iRGD-antiCD3 combined with PD-1 as evidenced by activation markers, Th1/Th2-cytokines, and killing capability against tumor cells in vitro. Moreover, to better mimic the physiological characteristics of in vivo solid tumors, we generated 3D spheroids from target cell lines. Spheroids were stained with a Viability/Cytotoxicity Assay Kit and examined by confocal microscopy to study the in vitro antitumor effect of T cells co-administered with combination iRGD-antiCD3 and PD-1 blockade. The mouse peritoneal metastatic gastric tumor model was employed. The synergistic antitumor effect and safety profiles in vivo were evaluated by tumor and body weight of tumor-bearing mice. RESULTS: We found that expression of both PD-1 and PD-L1 were increased as resistance to iRGD-antiCD3 treatment. We found that PD-1 blockade partially restored T cell activation as evidenced by elevated activation markers, Th1-cytokines, and killing capability against tumor cells in vitro. The combination of PD-1 blockade consistently and significantly increased cord blood-derived T cell cytotoxicity against 3D tumor spheroids. In vivo, we observed synergistic antitumor activity without obvious side effects. CONCLUSION: These results demonstrated that combining iRGD-antiCD3 with PD-1 blockade could further improve antitumor efficacy of T cells, and this strategy holds great potential for the treatment of solid malignancies.

DSG2 expression is low in colon cancer and correlates with poor survival.

BACKGROUND: Desmoglein2 (DSG2) is a transmembrane protein that helps regulate intercellular connections and contributes to desmosome assembly. Desmosome are associated with cell adhesion junctions, which play an important role in cancer progression specially cancer cell migration and invasion. However, DSG2 expression in colon cancer (CC) and its association with CC patients' overall survival (OS) are still unclear. METHODS: We collected 587 CC samples, 41 colitis tissues and 114 pericarcinomatous tissues, as well as corresponding clinicopathological data about the patients who contributed them. All samples were tested immunohistochemically in tissue microarrays. Kaplan-Meier method was used for calculating patient survival. Univariate and multivariate analyses was used for investigating DGS2 link with CC patient's clinicopathological factors. Bioinformatics analysis was also used in study. RESULTS: The results showed that DSG2 expression was lower in CC tissues than in pericarcinomatous tissues (P < 0.001). DSG2 expression was associated with differentiation (P = 0.033), lymph node metastasis (P = 0.045), distant metastasis (P = 0.006) and AJCC stage (P < 0.001). Univariate analysis indicated that poor OS in patients with CC was associated with low DSG2 expression (P < 0.001), tumor size (P < 0.001), lymph node metastasis (P < 0.001), distant metastasis (P < 0.001), AJCC stage (P < 0.001) and venous invasion (P < 0.001). In multivariate analysis, low DSG2 expression (P < 0.001), distant metastasis (P < 0.001), AJCC stage (P = 0.002), venous invasion (P < 0.001) were independent prognostic factors for CC patients. Bioinformatics analysis indicated that low DSG2 expression affects protein activation, regulates the P53-related pathway in CC, and activates the EGFR pathway. CONCLUSIONS: The results suggest that low DSG2 expression is associated with poor survival for CC patients. DSG2 could be a prognostic biomarker for CC.

c-Met-targeted chimeric antigen receptor T cells inhibit hepatocellular carcinoma cells in vitro and in vivo.

c-Met is a hepatocyte growth factor receptor overexpressed in many tumors such as hepatocellular carcinoma (HCC). Therefore, c-Met may serve as a promising target for HCC immunotherapy. Modifying T cells to express c-Met-specific chimeric antigen receptor (CAR) is an attractive strategy in treating c-Met-positive HCC. This study aimed to systematically evaluate the inhibitory effects of 2 nd- and 3 rd-generation c-Met CAR-T cells on hepatocellular carcinoma (HCC) cells. Here, 2 nd- and 3 rd-generation c-Met CARs containing an anti-c-Met single-chain variable fragment (scFv) as well as the CD28 signaling domain and CD3ζ (c-Met-28-3ζ), the CD137 signaling domain and CD3ζ (c-Met-137-3ζ), or the CD28 and CD137 signaling domains and CD3ζ (c-Met-28-137-3ζ) were constructed, and their abilities to target c-Met-positive HCC cells were evaluated in vitro and in vivo. All c-Met CARs were stably expressed on T cell membrane, and c-Met CAR-T cells aggregated around c-Met-positive HCC cells and specifically killed them in vitro. c-Met-28-137-3ζ CAR-T cells secreted more interferon-gamma (IFN-γ) and interleukin 2 (IL-2) than c-Met-28-3ζ CAR-T cells and c-Met-137-3ζ CAR-T cells. Compared with c-Met low-expressed cells, c-Met CAR-T cells secreted more cytokines when co-cultured with c-Met high-expressed cells. Moreover, c-Met-28-137-3ζ CAR-T cells eradicated HCC more effectively in xenograft tumor models compared with the control groups. This study suggests that 3 rd-generation c-Met CAR-T cells are more effective in inhibiting c-Met-positive HCC cells than 2 nd-generation c-Met CAR-T cells, thereby providing a promising therapeutic intervention for c-Met-positive HCC.

Influence of patient characteristics on chimeric antigen receptor T cell therapy in B-cell acute lymphoblastic leukemia.

CD19-specific chimeric antigen receptor T cell (CD19 CAR T) therapy has shown high remission rates in patients with refractory/relapsed B-cell acute lymphoblastic leukemia (r/r B-ALL). However, the long-term outcome and the factors that influence the efficacy need further exploration. Here we report the outcome of 51 r/r B-ALL patients from a non-randomized, Phase II clinical trial (ClinicalTrials.gov number: NCT02735291). The primary outcome shows that the overall remission rate (complete remission with or without incomplete hematologic recovery) is 80.9%. The secondary outcome reveals that the overall survival (OS) and relapse-free survival (RFS) rates at 1 year are 53.0 and 45.0%, respectively. The incidence of grade 4 adverse reactions is 6.4%. The trial meets pre-specified endpoints. Further analysis shows that patients with extramedullary diseases (EMDs) other than central nervous system (CNS) involvement have the lowest remission rate (28.6%). The OS and RFS in patients with any subtype of EMDs, higher Tregs, or high-risk genetic factors are all significantly lower than that in their corresponding control cohorts. EMDs and higher Tregs are independent high-risk factors respectively for poor OS and RFS. Thus, these patient characteristics may hinder the efficacy of CAR T therapy.

Construction of a novel prognostic-predicting model correlated to ovarian cancer.

BACKGROUND: Ovarian cancer (OC) is one of the most lethal gynecological cancers worldwide. The pathogenesis of the disease and outcomes prediction of OC patients remain largely unclear. The present study aimed to explore the key genes and biological pathways in ovarian carcinoma development, as well as construct a prognostic model to predict patients' overall survival (OS). RESULTS: We identified 164 up-regulated and 80 down-regulated differentially expressed genes (DEGs) associated with OC. Gene Ontology (GO) term enrichment showed DEGs mainly correlated with spindle microtubes. For Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, cell cycle was mostly enriched for the DEGs. The protein-protein interaction (PPI) network yielded 238 nodes and 1284 edges. Top three modules and ten hub genes were further filtered and analyzed. Three candidiate drugs targeting for therapy were also selected. Thirteen OS-related genes were selected and an eight-mRNA model was present to stratify patients into high- and low-risk groups with significantly different survival. CONCLUSIONS: The identified DEGs and biological pathways may provide new perspective on the pathogenesis and treatments of OC. The identified eight-mRNA signature has significant clinical implication for outcome prediction and tailored therapy guidance for OC patients.

Trop2 Promotes Multidrug Resistance by Regulating Notch1 Signaling Pathway in Gastric Cancer Cells.

BACKGROUND Chemotherapy is widely used in gastric cancer treatment, but multidrug resistance remains a leading cause of chemotherapy failure. Trop2 is highly expressed in gastric tumor tissues and greatly influences cancer progression. However, little is known about the relationship between Trop2 and drug resistance in gastric cancer. MATERIAL AND METHODS In the present study, Trop2 was knocked down in BGC823 cells and overexpressed in HGC27. CCK-8 assay was performed to explore the relationship of Trop2 expression and cell proliferation treated with anticancer drugs. Flow cytometry was performed to assess the relationship between Trop2 and cell apoptosis after chemotherapy. Subcutaneous xenograft models were generated to explore the curative effect of DDP to GC in vivo. MRP1 and Notch1 expressions were assessed by Western blot. RESULTS Trop2 decreased cell proliferation inhibition and apoptosis after chemotherapeutic treatments. DDP showed stronger therapeutic effects on Trop2-knockdown tumor than control in vivo. MRP1 and Notch1 signaling pathway were confirmed to participate in Trop2-induced drug resistance. CONCLUSIONS Our findings suggest that Trop2 promotes the resistance of gastric cancer to chemotherapy by activating the Notch1 pathway.

CD137 Co-Stimulation Improves The Antitumor Effect Of LMP1-Specific Chimeric Antigen Receptor T Cells In Vitro And In Vivo.

PURPOSE: In previous research, we have found that LMP1-specific chimeric antigen (HELA/CAR) T cells can specifically recognize and kill LMP1-positive NPC cells. However, the tumor-inhibitory effectiveness of HELA/CART cells needs to be enhanced. METHODS: We created two CARs that contain the T cell receptor-ζ (TCR-ζ) signal transduction domain with the CD28 and CD137 (4-1BB) or CD134 (OX-40) intracellular domains in tandem (HELA/137CAR or HELA/134CAR). Then, the tumor-inhibitory functions of two new CAR-T cells were investigated, both in vitro and in vivo. RESULTS: The results showed that, after short-term expansion, primary human T cells were subjected to lentiviral gene transfer, resulting in large numbers of cells with >80% CAR expression. All CART cells were effective in killing SUNE1-LMP1 and C1R-neo cells, while HELA/137CART cells produced greater quantities of IFN-γ and IL-2 than HELA/CART cells. However, the level of IL-2 not INF-γ secreted by HELA/134CART cells was increased under the stimulation of LMP1 antigen. In an LMP1-positive NPC mouse xenograft model, HELA/137CART cells exhibited better antitumor activity and longer survival time in vivo compared with HELA/CAR T cells. CONCLUSION: The findings suggest that CD137 and CD28 is a better costimulatory signaling domain than CD28 only for optimizing tumor-inhibitory roles.

MAGE-A1 in lung adenocarcinoma as a promising target of chimeric antigen receptor T cells.

BACKGROUND: Cancer/testis antigens (CTAs) are a special type of tumor antigen and are believed to act as potential targets for cancer immunotherapy. METHODS: In this study, we first screened a rational CTA MAGE-A1 for lung adenocarcinoma (LUAD) and explored the detailed characteristics of MAGE-A1 in LUAD development through a series of phenotypic experiments. Then, we developed a novel MAGE-A1-CAR-T cell (mCART) using lentiviral vector based on our previous MAGE-A1-scFv. The anti-tumor effects of this mCART were finally investigated in vitro and in vivo. RESULTS: The results showed striking malignant behaviors of MAGE-A1 in LUAD development, which further validated the rationality of MAGE-A1 as an appropriate target for LUAD treatment. Then, the innovative mCART was successfully constructed, and mCART displayed encouraging tumor-inhibitory efficacy in LUAD cells and xenografts. CONCLUSIONS: Taken together, our data suggest that MAGE-A1 is a promising candidate marker for LUAD therapy and the MAGE-A1-specific CAR-T cell immunotherapy may be an effective strategy for the treatment of MAGE-A1-positive LUAD.

Overexpression of PSMA7 predicts poor prognosis in patients with gastric cancer.

Gastric cancer (GC) is the fourth most common tumor and the second most common cause of cancer-associated mortality worldwide. Current tumor biomarkers for GC, such as serum carcinoembryonic antigen and carbohydrate antigen 19-9, are not ideal due to their limited role as prognostic indicators for GC. Proteasome subunit α7 (PSMA7) is a multifunctional protein, which has been revealed to be involved in the development and progression of various types of malignancy. However, little is known about the role of PSMA7 in GC. In the present study, PSMA7 was identified to be overexpressed at the mRNA and protein levels in GC tissues, compared with in non-tumor tissues, using reverse transcription-quantitative PCR and immunohistochemistry. Furthermore, PSMA7 expression is associated with tumor invasion, lymph node metastasis, distant metastasis, and Tumor-Node-Metastasis stage. Univariate and multivariate Cox regression analysis identified that PSMA7 expression is an independent prognostic factor for poor survival. Kaplan-Meier survival curves revealed that high PSMA7 expression is associated with a poor prognosis in patients with GC. Overall, the results of the present study suggested that PSMA7 may be a promising biomarker for the prognosis of GC, and may represent a new diagnostic marker and molecular therapeutic target for GC.

BRD4 degrader ARV-825 produces long-lasting loss of BRD4 protein and exhibits potent efficacy against cholangiocarcinoma cells.

BRD4, a member of the bromodomain and extraterminal domain (BET) family and an important epigenetic reader, has emerged as an attractive oncology target. Cholangiocarcinoma is a lethal neoplasm without approved targeted therapies. BET bromodomain inhibitors have shown promising effects in certain cancers including cholangiocarcinoma. Recently developed BRD4 Proteolysis Targeting Chimera (PROTAC) compounds lead to fast and efficient degradation of BRD4 and provides longer-lasting effect than small molecule BRD4 inhibitors. In this study, we investigated the antitumor effect of a newly developed BRD4 degrader ARV-825 in cholangiocarcinoma. Immunohistochemistry and Western blotting were used to determine the expression level of BRD4. CCK-8 assay and BrdU ELISA assay were used to assess cell proliferation. Caspase 3/7 activity and Annexin V/PI staining were used to assess apoptosis. We demonstrated that BRD4 expression was elevated in cholangiocarcinoma tissues compared to normal bile duct or surrounding normal liver tissues. ARV-825 produced fast and long-lasting loss of BRD4 protein, resulting in more inhibition of CCA cell proliferation and induction of apoptosis than BRD4 inhibitors OTX-015 and JQ1. C-Myc is a well-known downstream target of BRD4. We found that ARV-825 suppressed c-Myc levels more effectively than BRD4 inhibitors. However, ARV-825 did not inhibit c-Myc expression in CCA cells with low basal c-Myc levels. Further analysis showed that ARV-825 significantly upregulated p21 expression and arrested cell cycle progression at G1 phase. In conclusion, BRD4 degrader ARV-825 leads to rapid and sustained degradation of BRD4 and is effective against cholangiocarcinoma.