BRD9 promotes the progression of gallbladder cancer via CST1 upregulation and interaction with FOXP1 through the PI3K/AKT pathway and represents a therapeutic target.

Gallbladder cancer (GBC) is highly aggressive and has poor prognosis, with most patients only diagnosed at an advanced stage. Furthermore, treatment options are limited, and their effect is unsatisfactory. Bromodomain-containing protein (BRD) is an epigenetic regulator that plays a carcinogenic role in several tumors, including squamous cell lung cancer, acute myeloid leukemia, synovial sarcoma, and malignant rhabdomyosarcoma. However, the expression, biological function, and molecular mechanisms of action of BRD9 in GBC are still unknown. Kaplan-Meier analysis, qRT-PCR, and analysis of clinical features were used to assess the clinical significance of BRD9 in GBC. Cell Counting Kit-8 and colony formation assays were performed to determine the effects of BRD9 on cell growth. The functional role of BRD9 in GBC was explored using qRT-PCR, western blotting, siRNA, and CHIP-qPCR. mRNA sequencing was performed to explore the underlying mechanisms of BRD9, and a nude mouse model of GBC was established to explore the anti-tumor effects of the BRD9 inhibitor I-BRD9 in vivo. BRD9 expression was elevated in GBC tissues compared with adjacent non-tumor tissues, and high BRD9 expression was associated with poor prognosis in patients with GBC. BRD9 knockdown by siRNA significantly decreased cell growth. Targeting BRD9 with I-BRD9 inhibited the proliferation of GBC cells without significant toxic effects. Additionally, I-BRD9 treatment suppressed CST1 expression in GBC cell lines, thereby inhibiting the PI3K-AKT pathway. The transcription factor FOXP1 was found to interact with BRD9 to regulate CST1 expression. Collectively, these results suggest that BRD9 may be a promising biomarker and therapeutic target for GBC.

PTBP3 Mediates IL-18 Exon Skipping to Promote Immune Escape in Gallbladder Cancer.

Gallbladder cancer (GBC) is the most common malignant tumor of the biliary system, with poor response to current treatments. Abnormal alternative splicing has been associated with the development of a variety of tumors. Combining the GEO database and GBC mRNA-seq analysis, it is found high expression of the splicing factor polypyrimidine region- binding protein 3 (PTBP3) in GBC. Multi-omics analysis revealed that PTBP3 promoted exon skipping of interleukin-18 (IL-18), resulting in the expression of ΔIL-18, an isoform specifically expressed in tumors. That ΔIL-18 promotes GBC immune escape by down-regulating FBXO38 transcription levels in CD8+T cells to reduce PD-1 ubiquitin-mediated degradation is revealed. Using a HuPBMC mouse model, the role of PTBP3 and ΔIL-18 in promoting GBC growth is confirmed, and showed that an antisense oligonucleotide that blocked ΔIL-18 production displayed anti-tumor activity. Furthermore, that the H3K36me3 promotes exon skipping of IL-18 by recruiting PTBP3 via MRG15 is demonstrated, thereby coupling the processes of IL-18 transcription and alternative splicing. Interestingly, it is also found that the H3K36 methyltransferase SETD2 binds to hnRNPL, thereby interfering with PTBP3 binding to IL-18 pre-mRNA. Overall, this study provides new insights into how aberrant alternative splicing mechanisms affect immune escape, and provides potential new perspectives for improving GBC immunotherapy.

Efficacy and long-term outcomes of single-balloon enteroscopy-assisted treatment for biliary obstruction after choledochojejunostomy.

BACKGROUND: To evaluate the long-term efficacy of single-balloon enteroscopy endoscopic retrograde cholangiography (SBE-ERC) for the treatment of biliary obstruction and to analyze the factors affecting the recurrence of benign bilioenteric anastomotic stricture after SBE-ERC treatment. METHODS: The clinical data of patients with biliary diseases treated with SBE-ERC after choledochojejunostomy in our hospital from January 2015 to December 2021 were analyzed retrospectively for the success rates of diagnosis and treatment and the incidence of complications. Patients who were diagnosed with benign bilioenteric anastomotic stricture were followed up. The independent factors affecting recurrence were obtained by univariate and multivariate analyses using the Kaplan‒Meier method and Cox proportional hazard regression model. RESULTS: A total of 289 SBE-ERCs were performed in 165 patients. The overall success rate was 83.0% (240/289). The incidence of postoperative complications was 5.2% (15/289). The 108 successfully treated patients diagnosed with benign bilioenteric anastomotic stricture were followed up. Twenty-six percent (29/108) of patients had recurrent stricture after SBE-ERC. The biliary patency rates at 1 year, 2 years and 5 years after SBE-ERC were 90.1%, 69.3%, and 53.9%, respectively. Single-factor analysis revealed the absence of intrahepatic biliary gas imaging during endoscopy ( χ 2 =5.366, P = 0.021), a diameter of balloon dilatation during the last endoscopic treatment less than 0.8 cm ( χ 2 =4.552, P = 0.033), and the presence of a thread in the anastomosis ( χ 2 =8.921, P = 0.003) as risk factors for recurrence. A non-indwelling biliary plastic stent ( χ 2 =14.868, P < 0.001) and undergoing only one ERCP treatment ( χ 2 =13.313, P = 0.001) were risk factors for the recurrence of benign stricture after SBE-ERC resection. Multivariate analysis revealed that the absence of a stent (HR = 0.15, 95% CI 0.06-0.40, P = 0.001), absence of intrahepatic biliary gas imaging during endoscopy (HR = 0.39, 95% CI 0.17-0.91, P = 0.03) and the presence of a thread in the anastomosis (HR = 3.69, 95% CI 1.59-8.57, P = 0.002) were independent risk factors for stricture recurrence. CONCLUSIONS: Treating biliary disease after choledochojejunostomy with SBE-ERC is safe and effective, with a good immediate technical success rate and an acceptable incidence of complications. SBE-ERC has long-term efficacy in the treatment of benign bilioenteric anastomotic stricture. The absence of intrahepatic biliary gas imaging during endoscopy, non-indwelling biliary stents and the existence of anastomotic threads are independent risk factors for the recurrence of benign bilioenteric anastomotic stricture.

NONO promotes gallbladder cancer cell proliferation by enhancing oncogenic RNA splicing of DLG1 through interaction with IGF2BP3/RBM14.

Gallbladder cancer (GBC) is a highly malignant and rapidly progressing tumor of the human biliary system, and there is an urgent need to develop new therapeutic targets and modalities. Non-POU domain-containing octamer-binding protein (NONO) is an RNA-binding protein involved in the regulation of transcription, mRNA splicing, and DNA repair. NONO expression is elevated in multiple tumors and can act as an oncogene to promote tumor progression. Here, we found that NONO was highly expressed in GBC and promoted tumor cells growth. The dysregulation of RNA splicing is a molecular feature of almost all tumor types. Accordingly, mRNA-seq and RIP-seq analysis showed that NONO promoted exon6 skipping in DLG1, forming two isomers (DLG1-FL and DLG1-S). Furthermore, lower Percent-Spliced-In (PSI) values of DLG1 were detected in tumor tissue relative to the paraneoplastic tissue, and were associated with poor patient prognosis. Moreover, DLG1-S and DLG1-FL act as tumor promoters and tumor suppressors, respectively, by regulating the YAP1/JUN pathway. N6-methyladenosine (m6A) is the most common and abundant RNA modification involved in alternative splicing processes. We identified an m6A reader, IGF2BP3, which synergizes with NONO to promote exon6 skipping in DLG1 in an m6A-dependent manner. Furthermore, IP/MS results showed that RBM14 was bound to NONO and interfered with NONO-mediated exon6 skipping of DLG1. In addition, IGF2BP3 disrupted the binding of RBM14 to NONO. Overall, our data elucidate the molecular mechanism by which NONO promotes DLG1 exon skipping, providing a basis for new therapeutic targets in GBC treatment.

Ponicidin inhibited gallbladder cancer proliferation and metastasis by decreasing MAGEB2 expression through FOXO4.

BACKGROUND: Gallbladder cancer (GBC) is the most aggressively malignant tumor in the bile duct system. The prognosis for patients with GBC is extremely poor. Ponicidin is a diterpenoid compound extracted and purified from the traditional Chinese herb Rabdosia rubescens, and showed promising anti-cancer effects in a variety of tumors. However, Ponicidin has not been investigated in GBC. METHODS: CCK-8, colony formation assay and EdU-488 DNA synthesis assay were performed to investigate the effect of Ponicidin on GBC cells proliferation. Cell invasion and migration assays and wound-healing assay were used to explore the effect of Ponicidin on invasion and migration ability of GBC cells. mRNA-seq was adopted to explore the underlying mechanisms. Western blot and immunohistochemical staining were conducted to detect the protein level. CHIP assay and dual-luciferase assay were used to validate binding motif. Nude mouse model of GBC was used to assess the anti-tumor effect and safety of Ponicidin. RESULTS: Ponicidin inhibited the proliferation and cell invasion and migration of GBC cells in vitro. Moreover, Ponicidin exerted anti-tumor effects by down-regulating the expression of MAGEB2. Mechanically, Ponicidin upregulated the FOXO4 expression and promoted it to accumulate in nucleus to inhibit the transcript of MAGEB2. Furthermore, Ponicidin suppressed tumor growth in the nude mouse model of GBC with excellent safety. CONCLUSION: Ponicidin may be a promising agent for the treatment of GBC effectively and safely.

Preoperative pancreatic CT value is related to pancreatic fistula after pancreaticoduodenectomy: a retrospective study.

Background: Pancreatic fistula (PF) is the main complication in patients undergoing pancreaticoduodenectomy. Computed tomography (CT) value can reflect pancreatic tissue characteristics which is related to PF. This study was designed to study the relationship between the preoperative CT value and pancreatic fistula. Methods: We retrospectively reviewed the clinical and medical data of patients undergoing pancreaticoduodenectomy from 2017 to 2021. The pancreatic CT value and the CT value ratios of the pancreas and abdominal aorta (PCT/ACT) were measured and compared between the PF group and non-PF group. The values in different PF severity groups were compared using variance analysis. A cut-off value was selected by receiver operating characteristic (ROC) curve. Single-factor and multiple-factor analysis were performed to evaluate Correlation between PF and CT. Results: One hundred and twenty-seven cases were included in this study. The PCT/ACT in the PF group was significantly lower than that in the non-PF group (P<0.001), and the PCT/ACT value was correlatively lower in the severe PF group than in the mild PF group (P=0.008). A cutoff value of 0.99 was selected by ROC curves analysis. Further multifactor analysis identified PCT/ACT <0.99 to be an independent preoperative predictor [odds ratio (OR): 11.3, P<0.01]. Conclusions: The preoperative pancreatic CT value can indirectly reflect the histological condition of the pancreas and thus may related to postoperative PF after pancreaticoduodenectomy and provide useful information for surgeons in deciding upon the pancreaticojejunostomy method.

Potential factors affecting success rate and long term outcome in single balloon enteroscopy-assisted therapeutic endoscopic retrograde cholangiopancreatography in patients with pancreaticojejunal anastomotic stenosis: a retrospective study.

Background: Pancreaticojejunal anastomotic stenosis (PJS) after pancreaticoduodenectomy (PD) is difficult to treat. Single-balloon enteroscope-assisted endoscopic retrograde pancreatography (SBE-assisted ERP) is a safe way to treat PJS with the strength of minimally invasion and repeatability, but since its technical difficulty and few patient number, data on long-term outcomes remain limited. The optimal treatment is still unknown. We aim to study the safety, effectiveness, and long-term outcome of single balloon enteroscopy-assisted (SBE-assisted) therapeutic ERP in patients with PJS in this study. Methods: The clinical information of patients undergoing SBE-assisted therapeutic ERP from March 2016 to March 2021 were retrospectively analyzed. All patients were diagnosed as PJS and without any contraindication for therapeutic endoscopy. Treatment details, postoperative complications, factors influencing technical success rate were evaluated. Long-term outcomes results were obtained by clinical or telephone follow-up. Results: Sixteen patients with median age of 51 years were included in this study, surgical reconstruction methods including PD with Whipple reconstruction, PD with Child reconstruction, pylorus-preserving pancreaticoduodenectomy (PpPD) with Whipple reconstruction. Eight patients were successfully treated. No serious complications happened. Risk factors for the failure of pancreaticojejunal anastomotic site identification include the digestive tract reconstruction sequence, pancreaticojejunostomy method, pancreatic duct tube implantation, pancreatic duct width before surgery, and pancreatic fistula during perioperative period. The median follow-up time was 77.2 months, the mean indwelling time of the stent was 62.3 months [interquartile range (IQR), 6.8-153.7 months]. Two of eight patients developed recurrent PJS. The variation in body mass index (BMI) was +2.46 in the non-recurrence group compared to -1.09 in the recurrence group and -2.12 in the endoscopic retrograde cholangiopancreatography (ERCP) treatment failure group. Conclusions: ERP intervention should be carried out early once PJS occurs in order to increase success rate. BMI is a crucial indicator which can reflex PJS rehabilitation degree during follow-up. In order to reduce PJS recurrence rate, a wider pancreatic stent and a longer stent indwelling time are recommended.

Inhibition of XPO1 impairs cholangiocarcinoma cell proliferation by triggering p53 intranuclear accumulation.

BACKGROUND: XPO1 mediates the nuclear export of several proteins, mainly tumor suppressors. KPT-330 (Selinexor) is a selective inhibitor of XPO1 that has demonstrated good therapeutic effects in hematologic cancers. METHODS: We used TCGA and GTEx pan-cancer database to evaluate XPO1 mRNA expression in various tumors. Cell proliferation assay and colony formation assay were used to analyze the in vitro antitumor effects of XPO1 inhibitor KPT-330. Western blot was performed to explore the specific mechanisms. RESULTS: We found that XPO1 was highly expressed across a range of cancers and associated with poor prognosis in hepatobiliary and pancreatic tumors. We revealed that the XPO1 inhibitor KPT-330 triggered the nuclear accumulation of the p53 protein and significantly disrupted the proliferation of cholangiocarcinoma cells. Mechanistically, the XPO1 inhibitor, KPT-330, reduced BIRC6 expression by inhibiting the PI3K/AKT pathway to decrease p53 degradation and improve its stability. CONCLUSION: Therefore, XPO1 may be a potential therapeutic target in cholangiocarcinoma, mediated by its effects on KPT-330.

Inhibition of XPO1 with KPT-330 induces autophagy-dependent apoptosis in gallbladder cancer by activating the p53/mTOR pathway.

BACKGROUND: Gallbladder cancer (GBC) is a highly aggressive malignant cancer in the biliary system with poor prognosis. XPO1 (chromosome region maintenance 1 or CRM1) mediates the nuclear export of several proteins, mainly tumor suppressors. Thus, XPO1 functions as a pro-oncogenic factor. KPT-330 (Selinexor) is a United States Food and Drug Administration approved selective inhibitor of XPO1 that demonstrates good therapeutic effects in hematologic cancers. However, the function of XPO1 and the effect of KPT-330 have not been reported in GBC. METHODS: We analyzed the correlation between XPO1 expression levels by q-PCR and clinical features of GBC patients. Cell proliferation assays were used to analyze the in vitro antitumor effects of XPO1 inhibitor KPT-330. mRNA sequencing was used to explore the underlying mechanisms. Western blot was performed to explore the relationship between apoptosis and autophagy. The in vivo antitumor effect of KPT-330 was investigated in a nude mouse model of gallbladder cancer. RESULTS: We found that high expression of XPO1 was related to poor prognosis of GBC patients. We observed that XPO1 inhibitor KPT-330 inhibited the proliferation of GBC cells in vitro. Furthermore, XPO1 inhibitor KPT-330 induced apoptosis by reducing the mitochondrial membrane potential and triggering autophagy in NOZ and GBC-SD cells. Indeed, XPO1 inhibitor KPT-330 led to nuclear accumulation of p53 and activated the p53/mTOR pathway to regulate autophagy-dependent apoptosis. Importantly, KPT-330 suppressed tumor growth with no obvious toxic effects in vivo. CONCLUSION: XPO1 may be a promising prognostic indicator for GBC, and KPT-330 appears to be a potential drug for treating GBC effectively and safely.

UBAP2L promotes gastric cancer metastasis by activating NF-κB through PI3K/AKT pathway.

Ubiquitin-associated protein 2-like (UBAP2L) is highly expressed in various types of tumors and has been shown to participate in tumor growth and metastasis; however, its role in gastric cancer (GC) remains unknown. In this study, we observed that UBAP2L expression was markedly elevated in GC tissues and five GC cell lines. Higher expression of UBAP2L was associated with poor prognosis as revealed by bioinformatics analysis on online websites and laboratory experiments. Knockdown of UBAP2L impeded the migration and invasion abilities of GC cell lines. In contrast, its overexpression enhanced the migration and invasion abilities of GC cell lines. Overexpression of UBAP2L also increased the number and size of lung metastatic nodules in vivo. According to the results of mass spectrometry and pathway annotation of the identified proteins, the PI3K/AKT pathway was found to be related to UBAP2L regulation. Further exploration and rescue experiments revealed that UBAP2L stimulates the expression and nuclear aggregation of p65 and promotes the expression of SP1 by activating the PI3K/AKT pathway. In summary, our findings indicate that UBAP2L regulates GC metastasis through the PI3K/AKT/SP1/NF-κB axis. Thus, targeting UBAP2L may be a potential therapeutic strategy for GC.

Development and Validation of a Prognostic Nomogram Based on the Systemic Immune-Inflammation Index for Resectable Gallbladder Cancer to Predict Survival and Chemotherapy Benefit.

OBJECTIVES: To investigate the prognostic significance of the systemic immune-inflammation index (SII) in patients after radical cholecystectomy for gallbladder cancer (GBC) using overall survival (OS) as the primary outcome measure. METHODS: Based on data from a multi-institutional registry of patients with GBC, significant prognostic factors after radical cholecystectomy were identified by multivariate Cox proportional hazards model. A novel staging system was established, visualized as a nomogram. The response to adjuvant chemotherapy was compared between patients in different subgroups according to the novel staging system. RESULTS: Of the 1072 GBC patients enrolled, 691 was randomly selected in the discovery cohort and 381 in the validation cohort. SII>510 was found to be an independent predictor of OS (hazard ratio [HR] 1.90, 95% confidence interval [CI] 1.42-2.54). Carbohydrate antigen 199(CA19-9), tumor differentiation, T stage, N stage, margin status and SII were involved in the nomogram. The nomogram showed a superior prediction compared with models without SII (1-, 3-, 5-year integrated discrimination improvement (IDI):2.4%, 4.1%, 5.4%, P<0.001), and compared to TNM staging system (1-, 3-, 5-year integrated discrimination improvement (IDI):5.9%, 10.4%, 12.2%, P<0.001). The C-index of the nomogram in predicting OS was 0.735 (95% CI 0.683-0.766). The novel staging system based on the nomogram showed good discriminative ability for patients with T2 or T3 staging and with negative lymph nodes after R0 resection. Adjuvant chemotherapy offered significant survival benefits to these patients with poor prognosis. CONCLUSIONS: SII was an independent predictor of OS in patients after radical cholecystectomy for GBC. The new staging system identified subgroups of patients with T2 or T3 GBC with negative lymph nodes who benefited from adjuvant chemotherapy. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, identifier (NCT04140552).

ESRRA promotes gastric cancer development by regulating the CDC25C/CDK1/CyclinB1 pathway via DSN1.

Background: Estrogen-related receptor-α (ESRRA) is an orphan nuclear receptor, expressing at high level in exuberant metabolism organs and acting as transcription factor. High expression was found in many malignances but no research was done in gastric cancer (GC), where lipid metabolism disorder is common. Methods: Kaplan-Meier plot was utilized to find the relationship between ESRRA expression and patients' prognoses. The expression level of ESRRA was measured by real-time PCR. The protein expression levels were tested with western-blot and immunohistochemistry. Cell cycle and apoptosis was identified with flow cytometry. RNA-seq, bioinformatics analysis, dual-luciferase assay and ChIP assay were used to predict and validate ESRRA's target gene and binding motif. Animal models were also introduced in our study. Results: ESRRA expression is notably higher in GC cell lines and high ESRRA levels are correlated to poor prognoses. ESRRA silencing decreased GC cell viability, migration, and invasion capacities. Its downstream gene DSN1 was spotted by RNA-seq and confirmed by later bioinformatics analyses, dual-luciferase, and ChIP assays. Western-blot showed G2M arrest caused by ESRRA silencing was via CDC25C-CDK1-Cyclin B1 pathway. Conclusion: ESRRA/DSN1/CDC25C-CDK1-Cyclin B1 is of great importance in GC development. ESRRA could be a potential target as well as prognostic marker in GC.

Prognostic significance of regional lymphadenectomy in T1b gallbladder cancer: Results from 24 hospitals in China.

BACKGROUND: Whether regional lymphadenectomy (RL) should be routinely performed in patients with T1b gallbladder cancer (GBC) remains a subject of debate. AIM: To investigate whether RL can improve the prognosis of patients with T1b GBC. METHODS: We studied a multicenter cohort of patients with T1b GBC who underwent surgery between 2008 and 2016 at 24 hospitals in 13 provinces in China. The log-rank test and Cox proportional hazards model were used to compare the overall survival (OS) of patients who underwent cholecystectomy (Ch) + RL and those who underwent Ch only. To investigate whether combined hepatectomy (Hep) improved OS in T1b patients, we studied patients who underwent Ch + RL to compare the OS of patients who underwent combined Hep and patients who did not. RESULTS: Of the 121 patients (aged 61.9 ± 10.1 years), 77 (63.6%) underwent Ch + RL, and 44 (36.4%) underwent Ch only. Seven (9.1%) patients in the Ch + RL group had lymph node metastasis. The 5-year OS rate was significantly higher in the Ch + RL group than in the Ch group (76.3% vs 56.8%, P = 0.036). Multivariate analysis showed that Ch + RL was significantly associated with improved OS (hazard ratio: 0.51; 95% confidence interval: 0.26-0.99). Among the 77 patients who underwent Ch + RL, no survival improvement was found in patients who underwent combined Hep (5-year OS rate: 79.5% for combined Hep and 76.1% for no Hep; P = 0.50). CONCLUSION: T1b GBC patients who underwent Ch + RL had a better prognosis than those who underwent Ch. Hep + Ch showed no improvement in prognosis in T1b GBC patients. Although recommended by both the National Comprehensive Cancer Network and Chinese Medical Association guidelines, RL was only performed in 63.6% of T1b GBC patients. Routine Ch + RL should be advised in T1b GBC.

Topoisomerase II alpha promotes gallbladder cancer proliferation and metastasis through activating phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway.

BACKGROUND: Topoisomerase II alpha (TOP2A) has been reported to play a crucial role in the tumorigenesis of various cancer types. However, the biological role of TOP2A in gallbladder cancer (GBC) remains unknown. The current study aimed to explore the function and potential mechanism of TOP2A in GBC. METHODS: Based on Gene Expression Profiling Interactive Analysis data, we found TOP2A was significantly up-regulated in GBC tissues and resulting in shorter overall survival. Quantitative real-time polymerase chain reaction and immunohistochemistry were conducted to detect the expression of TOP2A in 45 pairs of GBC tissues and adjacent non-tumor tissues. In vitro, cell proliferation, migration, and invasion ability were examined by cell counting kit-8 and transwell assay, respectively. Epithelial-mesenchymal transition (EMT) related and phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway-related markers were measured by Western blotting. Xenograft model assay was performed to evaluate the effect of TOP2A in vivo. RESULTS: TOP2A was found up-regulated in GBC (tumor vs. normal, 12.62 vs. 0.34) and correlated with the late tumor node metastasis stage (P = 0.0032), present of lymph node metastasis (P = 0.0273), and poor prognosis in GBC patients (log-rank P = 0.028). In vitro and in vivo assays showed that knockdown of TOP2A notably inhibited cell proliferation, migration, invasion, EMT process, and tumor growth in GBC. In addition, TOP2A down-regulation significantly decreased the protein levels of phosphor (p)-PI3K, p-Akt, and p-mTOR. CONCLUSION: Our study demonstrates that TOP2A was overexpressed in GBC and associated with poor prognosis in GBC patients. TOP2A promotes GBC cell proliferation, migration, invasion, EMT process, and tumor growth through activating PI3K/Akt/mTOR signaling pathway, and may serve as a novel prognostic biomarker and therapeutic target for GBC.

MicroRNA-1275 inhibits cell migration and invasion in gastric cancer by regulating vimentin and E-cadherin via JAZF1.

BACKGROUND: Emerging evidence has shown that miR-1275 plays a critical role in tumour metastasis and the progression of various types of cancer. In this study, we analysed the role and mechanism of miR-1275 in the progression and prognosis of gastric cancer (GC). METHODS: Target genes of miR-1275 were identified and verified by luciferase assay and Western blotting. The function of miR-1275 in invasion and metastasis was analysed in vitro and in vivo in nude mice. The signal pathway regulated by miR-1275 was examined by qRT-PCR, Western blotting and chromatin immunoprecipitation analyses. The expression of miR-1275and JAZF1 were measured in specimens of GC and adjacent non cancerous tissues. RESULTS: We identified JAZF1 as a direct miR-1275 target. miR-1275 supresses migration and invasion of GC cells in vitro and in vivo, which was restored by JAZF1 overexpression. Moreover, JAZF1 was recognized as a direct regulator of Vimentin. Knocking-down miR-1275 or overexpressing JAZF1 resulted in upregulation of Vimentin but downregulation of E-cadherin. Meanwhile, we validated in 120 GC patients specimens that low miR-1275expression and high JAZF1 mRNA expression levels were closely associated with lymph node metastasis and poor prognosis. The expression of JAZF1 in protein level displayed the correlations with Vimentin but inversely with E-cadherin. CONCLUSIONS: Increased miR-1275 expression inhibited GC metastasis by regulating vimentin/E-cadherin via direct suppression of JAZF1expression, suggesting that miR-1275 is a tumour-suppressor miRNA with the potential as a prognostic biomarker or therapeutic target in GC.

LncRNA-PAGBC acts as a microRNA sponge and promotes gallbladder tumorigenesis.

Long noncoding RNAs (lncRNAs) play roles in the development and progression of many cancers; however, the contributions of lncRNAs to human gallbladder cancer (GBC) remain largely unknown. In this study, we identify a group of differentially expressed lncRNAs in human GBC tissues, including prognosis-associated gallbladder cancer lncRNA (lncRNA-PAGBC), which we find to be an independent prognostic marker in GBC Functional analysis indicates that lncRNA-PAGBC promotes tumour growth and metastasis of GBC cells. More importantly, as a competitive endogenous RNA (ceRNA), lncRNA-PAGBC competitively binds to the tumour suppressive microRNAs miR-133b and miR-511. This competitive role of lncRNA-PAGBC is required for its ability to promote tumour growth and metastasis and to activate the AKT/mTOR pathway. Moreover, lncRNA-PAGBC interacts with polyadenylate binding protein cytoplasmic 1 (PABPC1) and is stabilized by this interaction. This work provides novel insight on the molecular pathogenesis of GBC.

MYBL2 is a Potential Prognostic Marker that Promotes Cell Proliferation in Gallbladder Cancer.

BACKGROUND: Gallbladder cancer (GBC) is an aggressive and highly lethal biliary tract malignancy, with extremely poor prognosis. In the present study, we analyzed the potential involvement of MYBL2, a member of the Myb transcription factor family, in the carcinogenesis of human GBC. METHODS: MYBL2 expression levels were measured in GBC and cholecystitis tissue specimens using quantitative real-time PCR (qRT-PCR) and immunohistochemical (IHC) assays. The effects of MYBL2 on cell proliferation and DNA synthesis were evaluated using Cell Counting Kit-8 assay (CCK-8), colony formation, and 5-ethynyl-2'-deoxyuridine (EdU) retention assay, flow cytometry analysis, western blot, and a xenograft model of GBC cells in nude mice. RESULTS: MYBL2 expression was increased in GBC tissues and associated with histological differentiation, tumour invasion, clinical stage and unfavourable overall survival in GBC patients. The downregulation of MYBL2 expression resulted in the inhibition of GBC cell proliferation, and DNA replication in vitro, and the growth of xenografted tumours in nude mice. Conversely, MYBL2 overexpression resulted in the opposite effects. CONCLUSIONS: MYBL2 overexpression promotes GBC cell proliferation through the regulation of the cell cycle at the S and G2/M phase transitions. Thus, MYBL2 could serve as a potential prognostic and therapeutic biomarker in GBC patients.

MicroRNA-29c-5p suppresses gallbladder carcinoma progression by directly targeting CPEB4 and inhibiting the MAPK pathway.

Gallbladder cancer (GBC) is a leading cause of cancer-related deaths worldwide, and its prognosis remains poor, with a 5-year survival rate of ~5%. Given the crucial role of microRNAs (miRNAs) in cancer metastasis, we aimed to analyze the expression and function of the metastasis-associated miRNA miR-29c-5p in GBC.We validated that expression of miR-29c-5p was significantly downregulated in GBC and was closely associated with lymph node metastasis, overall survival and disease-free survival in 40 GBC patients who were followed clinically. Ectopic overexpression of miR-29c-5p dramatically repressed proliferation, metastasis, and colony formation and induced apoptosis in vitro, and it suppressed tumorigenicity in vivo through the MAPK pathway. Cytoplasmic polyadenylation element binding protein 4 (CPEB4) was identified as a critical effector target of miR-29c-5p. Enforced expression of miR-29c-5p significantly inhibited the expression of CPEB4, and restoration of CPEB4 expression reversed the inhibitory effects of miR-29c-5p on GBC cell proliferation and metastasis. Transforming growth factor-ß (TGF-ß) upregulated CPEB4 by downregulating miR-29c-5p, leading to MAPK pathway activation. In conclusion, the TGF-ß/miR-29c-5p/CPEB4 axis has a pivotal role in the pathogenesis and poor prognosis of GBC, suggesting that miR-29c-5p is a tumor-suppressive miRNA that may serve as potential prognostic biomarker or therapeutic target for GBC.

The E545K mutation of PIK3CA promotes gallbladder carcinoma progression through enhanced binding to EGFR.

BACKGROUND: Gallbladder carcinoma (GBC) is the most common malignancy of the bile duct and patients with GBC have extremely poor prognoses. PIK3CA, which encodes the phosphoinositide 3-kinase (PI3K) subunit p110α, is frequently mutated in many cancers, including GBC. The function of the E545K mutation in GBC is not fully understood. METHODS: E545K mutation was determined in human GBC tissues by targeted sequencing. The effects of E545K mutation and PI3K selective inhibitor, A66 on GBC cells were evaluated using Cell Counting Kit-8 (CCK-8) cell Viability and transwell assays. The mechanisms of E545K mutation and A66 were analyzed by western blot and co-immunoprecipitation (Co-IP) assay. Subcutaneous xenograft models in nude mice were employed to evaluate the role of E545K mutation and A66 in GBC progression. RESULTS: The rate of PIK3CA E545K mutation in GBC patients was 6.15 %. And the survival of GBC patients was correlated with E545K mutation significantly (P < 0.05). The E545K mutation promoted proliferation, migration and invasion of GBC cells in vitro and tumor proliferation in vivo. A66 suppressed proliferation of GBC cells in vitro and tumor proliferation in vivo. CONCLUSION: The prognoses of patients with E545K mutation were worse than patients without this mutation. The E545K mutation promoted GBC progression through enhanced binding to EGFR and activating downstream akt activity. The PI3K selective inhibitor, A66, suppressed gallbladder carcinoma proliferation.