MicroRNA-92a-1-5p increases CDX2 by targeting FOXD1 in bile acids-induced gastric intestinal metaplasia.

BACKGROUND AND AIMS: Gastric intestinal metaplasia (IM) is common in the gastric epithelium of patients with chronic atrophic gastritis. CDX2 activation in IM is driven by reflux of bile acids and following chronic inflammation. But the mechanism underlying how bile acids activate CDX2 in gastric epithelium has not been fully explored. METHODS: We performed microRNA (miRNA) and messenger RNA (mRNA) profiling using microarray in cells treated with bile acids. Data integration of the miRNA/mRNA profiles with gene ontology (GO) analysis and bioinformatics was performed to detect potential miRNA-mRNA regulatory circuits. Transfection of gastric cancer cell lines with miRNA mimics and inhibitors was used to evaluate their effects on the expression of candidate targets and functions. Immunohistochemistry and in situhybridisation were used to detect the expression of selected miRNAs and their targets in IM tissue microarrays. RESULTS: We demonstrate a bile acids-triggered pathway involving upregulation of miR-92a-1-5p and suppression of its target FOXD1 in gastric cells. We first found that miR-92a-1-5p was increased in IM tissues and induced by bile acids. Moreover, miR-92a-1-5p was found to activate CDX2 and downstream intestinal markers by targeting FOXD1/FOXJ1 axis and modulating activation of nuclear factor kappa B (NF-κB) pathway. Furthermore, these effects were found to be clinical relevant, as high miR-92a-1-5p levels were correlated with low FOXD1 levels and high CDX2 levels in IM tissues. CONCLUSION: These findings suggest a miR-92a-1-5p/FOXD1/NF-κB/CDX2 regulatory axis plays key roles in the generation of IM phenotype from gastric cells. Suppression of miR-92a-1-5p and restoration of FOXD1 may be a preventive approach for gastric IM in patients with bile regurgitation.

POU2F2-oriented network promotes human gastric cancer metastasis.

BACKGROUND AND AIMS: Aberrant upregulation of POU2F2 expression has been discovered in metastatic gastric cancer (GC). However, the mechanisms underlying the aberrant upregulation and the potential functions of POU2F2 remain uncertain. DESIGN: The role and mechanism of POU2F2 in GC metastasis were investigated in gastric epithelial cells, GC cell lines and an experimental metastasis animal model by gain of function and loss of function. Upstream and downstream targets of POU2F2 were selected by bioinformatics and identified by luciferase reporter assay, electrophoretic mobility shift assay and chromatin immunoprecipitation PCR. The influence of miR-218 on its putative target genes (POU2F2, ROBO1 and IKK-ß) and GC metastasis was further explored via in vitro and in vivo approaches. RESULTS: Increased POU2F2 expression was detected in metastatic GC cell lines and patient samples. POU2F2 was induced by the activation of nuclear factor (NF)-κB and, in turn, regulated ROBO1 transcription, thus functionally contributing to GC metastasis. Finally, miR-218 was found to suppress GC metastasis by simultaneously mediating multiple molecules in the POU2F2-oriented network. CONCLUSIONS: This study demonstrated that NF-κB and the SLIT2/ROBO1 interaction network with POU2F2 as the central part may exert critical effects on tumour metastasis. Blocking the activation of the POU2F2-oriented metastasis network using miR-218 precursors exemplified a promising approach that sheds light on new strategies for GC treatment.

c-Myc-mediated epigenetic silencing of MicroRNA-101 contributes to dysregulation of multiple pathways in hepatocellular carcinoma.

UNLABELLED: The MYC oncogene is overexpressed in hepatocellular carcinoma (HCC) and has been associated with widespread microRNA (miRNA) repression; however, the underlying mechanisms are largely unknown. Here, we report that the c-Myc oncogenic transcription factor physically interacts with enhancer of zeste homolog 2 (EZH2), a core enzymatic unit of polycomb repressive complex 2 (PRC2). Furthermore, miR-101, an important tumor-suppressive miRNA in human hepatocarcinomas, is epigenetically repressed by PRC2 complex in a c-Myc-mediated manner. miR-101, in turn, inhibits the expression of two subunits of PRC2 (EZH2 and EED), thus creating a double-negative feedback loop that regulates the process of hepatocarcinogenesis. Restoration of miR-101 expression suppresses multiple malignant phenotypes of HCC cells by coordinate repression of a cohort of oncogenes, including STMN1, JUNB, and CXCR7, and further increases expression of endogenous miR-101 by inhibition of PRC2 activation. In addition, co-overexpression of c-Myc and EZH2 in HCC samples was closely associated with lower expression of miR-101 (P < 0.0001) and poorer prognosis of HCC patients (P < 0.01). CONCLUSIONS: c-Myc collaborates with EZH2-containing PRC2 complex in silencing tumor-suppressive miRNAs during hepatocarcinogenesis and provides promising therapeutic candidates for human HCC.

Challenges in the management of acute peptic ulcer bleeding.

Acute upper gastrointestinal bleeding is a common medical emergency worldwide, a major cause of which are bleeding peptic ulcers. Endoscopic treatment and acid suppression with proton-pump inhibitors are cornerstones in the management of the disease, and both treatments have been shown to reduce mortality. The role of emergency surgery continues to diminish. In specialised centres, radiological intervention is increasingly used in patients with severe and recurrent bleeding who do not respond to endoscopic treatment. Despite these advances, mortality from the disorder has remained at around 10%. The disease often occurs in elderly patients with frequent comorbidities who use antiplatelet agents, non-steroidal anti-inflammatory drugs, and anticoagulants. The management of such patients, especially those at high cardiothrombotic risk who are on anticoagulants, is a challenge for clinicians. We summarise the published scientific literature about the management of patients with bleeding peptic ulcers, identify directions for future clinical research, and suggest how mortality can be reduced.

Polymorphisms in the vitamin D receptor gene and risk of primary biliary cirrhosis: a meta-analysis.

BACKGROUND AND AIM: Primary biliary cirrhosis (PBC) is a chronic and progressive cholestatic autoimmune liver disease. Although many studies have evaluated the association between many functional polymorphisms in the vitamin D receptor (VDR) gene and PBC risk, debates still exist. Our aim is to evaluate the association between VDR gene polymorphisms, including TaqI (rs731236), BsmI (rs1544410), and ApaI (rs7975232), and the risk of PBC by a systematic review. METHODS: We searched literatures in PubMed, SCOPUS, and EMBASE until July 2013. We calculated pooled odds ratios (OR) and 95% confidence intervals (CIs) using a fixed effects model or a random effects model for the risk to PBC associated with different VDR gene polymorphisms. And the heterogeneity assumption decided the effect model. RESULTS: A total of six relevant studies, with 1322 PBC cases and 2264 controls, were included in this meta-analysis. The results indicated that TaqI (rs731236) polymorphism was significantly associated with PBC risk (for T vs t OR = 0.75, 95% CI 0.63, 0.89, Pz = 0.001; TT + Tt vs tt OR = 0.62, 95% CI 0.44, 0.86, Pz = 0.005; OR = 0.74, 95% CI 0.58, 0.94, Pz = 0.016 for recessive model), while ApaI (rs7975232) or BsmI (rs1544410) polymorphism did not. CONCLUSION: Based on current evidences from published studies, the cumulative effect of TaqI polymorphism in VDR was significantly associated with PBC. Larger studies with mixed ethnicity subjects and stratified by clinical and sub clinical characteristics are needed to validate our findings.

Increased expression of FOXQ1 is a prognostic marker for patients with gastric cancer.

Altered expression of forkhead box Q1 (FOXQ1) is observed in various types of human cancers. However, the clinical significance of FOXQ1 expression in gastric cancer (GC) remains largely unknown. The present study aims to explore the clinicopathological significance and prognostic value of FOXQ1 in GC. FOXQ1 messenger RNA (mRNA) and protein expression were determined by quantitative real-time reverse transcriptase-polymerase chain reaction and Western blot in 20 pairs of fresh frozen GC tissues and corresponding noncancerous tissues. Additionally, FOXQ1 expression was analyzed by immunohistochemistry in 158 clinicopathologically characterized GC cases. The correlation of FOXQ1 expression with patients' survival rate was assessed by Kaplan-Meier and Cox regression. Our results showed that the expression levels of FOXQ1 mRNA and protein in GC tissues were both significantly higher than those in non-cancerous tissues. Our results showed that the high expression of FOXQ1 in GC was related to tumor size (P = 0.026), histological grade (P = 0.021), lymph node involvement (P = 0.002), and tumor-node-metastasis stage (P = 0.028). Kaplan-Meier survival analysis showed that a high expression level of FOXQ1 resulted in a significantly poor prognosis of GC patients. Furthermore, Cox multivariates analysis indicated that FOXQ1 expression level was an independent prognostic factor for the overall survival rate of GC patients. In conclusion, overexpression of FOXQ1 is closely related to progression of GC and might be regarded as an independent predictor of poor prognosis for GC.

HER2 interacts with CD44 to up-regulate CXCR4 via epigenetic silencing of microRNA-139 in gastric cancer cells.

BACKGROUND & AIMS: Human epidermal growth factor receptor 2 (HER2) (neu/ERBB2) is overexpressed on many types of cancer cells, including gastric cancer cells; HER2 overexpression has been associated with metastasis and poor prognosis. We investigated the mechanisms by which HER2 regulates cell migration and invasion. METHODS: HER2 expression or activity was reduced in gastric cancer cell lines using small interfering RNAs or the monoclonal antibody, trastuzumab. We identified proteins that interact with HER2 or microRNAs (miRNAs) involved in HER2 signaling. We used various software programs to identify miRNAs that regulate factors in the HER2 signaling pathway. We analyzed expression patterns of these miRNAs in gastric cancer cell lines and tumor samples from patients. RESULTS: We found that CD44 binds directly to HER2, which up-regulates the expression of metastasis-associated protein-1, induces deacetylation of histone H3 lysine 9, and suppresses transcription of microRNA139 (miR-139) to inhibit expression of its target gene, C-X-C chemokine receptor type 4 (CXCR4). Knockdown of HER2 and CD44 reduced invasive activity of cultured gastric cancer cells and suppressed tumor growth in nude mice. Lymph node metastasis was associated with high levels of HER2, CD44, and CXCR4, and reduced levels of miR-139 in human metastatic gastric tumors. Cultures of different types of metastatic cancer cells with histone deacetylase inhibitors and/or DNA methyltransferase resulted in up-regulation of miR-139. CONCLUSIONS: HER2 interaction with CD44 up-regulates CXCR4 by inhibiting expression of miR-139, at the epigenetic level, in gastric cancer cells. These findings indicate how HER2 signaling might promote gastric tumor progression and metastasis.

RUNX3 directly interacts with intracellular domain of Notch1 and suppresses Notch signaling in hepatocellular carcinoma cells.

RUNX3 takes a strong suppressive effect in many tumors including hepatocellular carcinoma (HCC). HES-1, a downstream target of Notch signaling, is shown to be decreased in human HCC cell line SMMC7721 with RUNX3 gene transfection. Since Notch signaling is oncogenic in HCC, RUNX3 might exert its inhibitory effect in HCC partly through the suppression on Notch signaling. To investigate the possible mechanism of the down-regulation of HES-1 by RUNX3, we performed Western blot and reporter assay and found that RUNX3 suppressed intracellular domain of Notch1 (ICN1)-mediated transactivation of Notch signaling while it did not alter the expression of ICN1 and recombination signal binding protein-J kappa (RBP-J) in SMMC7721 cells. Besides, confocal microscopy, co-immunoprecipitation and GST pull-down assays showed that RUNX3 could co-localize with ICN1 and RBP-J, forming a complex with these two molecules in nucleus of SMMC7721 cells by its direct interaction with ICN1. Furthermore, RUNX3 was recruited to RBP-J recognition motif of HES-1 promoter, which was identified by chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA). Taken together, these findings indicate that RUNX3 suppresses Notch signaling in HCC SMMC7721 cells by its interaction with ICN1 and thus recruitment to the RBP-J recognition motif of downstream genes of Notch signaling.

Healing effects of rebamipide and omeprazole in Helicobacter pylori-positive gastric ulcer patients after eradication therapy: a randomized double-blind, multinational, multi-institutional comparative study.

BACKGROUND AND AIMS: A recent placebo-controlled trial showed that rebamipide, which is a mucosal-protective antiulcer agent, promoted gastric ulcer healing without affecting the Helicobacter pylori status. We conducted a randomized, double-blind trial to compare the healing effects of rebamipide and the proton-pump inhibitor omeprazole in H. pylori-positive gastric ulcers after H. pylori eradication therapy. METHODS: After completion of 1 week of eradication therapy, 132 patients with H. pylori-positive gastric ulcer were enrolled in 5 Chinese and 4 Korean institutions. Patients were randomly assigned to take either 20 mg of omeprazole (n = 63) or 300 mg of rebamipide (n = 65) daily for 7 weeks. Healing was defined as complete recovery and S1 and S2 stage ulcer according to the Sakita-Miwa classification. RESULTS: Healing rates at 12 weeks were 81.5% (53/65) and 82.5% (52/63) in the rebamipide and omeprazole groups, respectively. There was no significant difference in treatment efficacy, as evidenced by gastric ulcer healing rates (absolute difference -1.0%; 95% confidence interval -10.7 to 8.7; p = 0.88). The H. pylori eradication rate and ulcer healing rate did not differ between the groups, the latter regardless of eradication outcome. CONCLUSIONS: Rebamipide is as effective as omeprazole in treating of H. pylori-positive gastric ulcer after eradication therapy.

[Early hepatic encephalopathy after transjugular intrahepatic portosystemic shunt: the risk factors and long-time survival].

OBJECTIVE: To identify the risk factors of early post-TIPS hepatic encephalopathy (HE) and the long-time survival of patients with or without early post-TIPS HE. METHODS: Consecutive cirrhotic patients who underwent TIPS for variceal rebleeding or refractory ascites in our center from January 2003 to December 2008 were included in this study. More than 60 clinical characteristics were enrolled in univariate analysis and logistic regression analysis to define the risk factors of HE in 3 months after TIPS procedure (early post-TIPS HE). The long-time survival of patients with or without early post-TIPS HE was compared by Cox regression with several covariates. RESULTS: According to our inclusion criteria, 190 patients were included. The median follow-up was 30.5 months. Lower serum concentration of fibrinogen and higher Child-Pugh score were the independent risk factors for suffering early post-TIPS HE. Patients without early post-TIPS HE after TIPS showed better prognosis than those with early post-TIPS HE after TIPS (P = 0.044). CONCLUSION: Patients with lower serum fibrinogen and higher Child-Pugh score before TIPS might be more probably attacked by early post-TIPS HE which indicated worse long-term survival.

Potent inhibition of human gastric cancer by HER2-directed induction of apoptosis with anti-HER2 antibody and caspase-3 fusion protein.

BACKGROUND AND AIMS: HER2, an oncogene, has been found to be over-expressed in 10-40% of human gastric carcinomas. The aims of this study were to investigate if a fusion protein consisting of anti-HER2 sFv and constitutively active caspase-3 was capable of inducing apoptosis in HER2-expressing human gastric cancer cells and blocking the growth of human gastric cancer xenografts in nude mice. METHODS: NIH3T3 cells stably transduced with the pcDNA3.1-HER-PE-CP3 recombinant plasmid containing a secretion signal, a single-chain anti-HER2 monoclonal antibody fragment, a Pseudomonas exotoxin A translocation domain and a constitutively active caspase-3 molecule were used to induce apoptosis in human gastric cancer cells both in vitro and in vivo. Immunofluorescence staining and western blotting were used to examine the expression of the recombinant protein HER-PE-CP3. Apoptosis was determined by flow cytometry and TUNEL assay. RESULTS: Co-cultivation of HER-PE-CP3/ NIH3T3 with human gastric cancer cells led to internalisation of HER-PE-CP3 and apoptosis in HER2-expressing human gastric cancer cells but not in HER2-negative cancer cells. Inoculation of HER-PE-CP3/NIH3T3 in nude mice resulted in potent inhibition of human gastric cancer xenografts and much prolonged survival time of the tumour-bearing mice compared with the control. Significantly more apoptotic cells were detected in xenografts in mice receiving HER-PE-CP3/NIH3T3 than in control mice. CONCLUSIONS: The HER-PE-CP3 chimeric molecule could induce selective apoptosis and potent growth inhibition of HER2-positive human gastric cancer cells and might represent a novel HER2-directed treatment option for human gastric cancer.

Mortality and Readmission Rates After Heart Failure: A Systematic Review and Meta-Analysis.

OBJECTIVE: The current work aimed to examine the rates of and risk factors for mortality and readmission after heart failure (HF). SETTING: A systematic search was carried out in PubMed, the Cochrane Library, and EMBASE to identify eligible reports. The random-effects model was utilized to evaluate the pooled results. PARTICIPANTS: A total of 27 studies with 515,238 participants were finally meta-analysed. The HF patients had an average age of 76.3 years, with 51% of the sample being male, in the pooled analysis. PRIMARY AND SECONDARY OUTCOME MEASURES: The outcome measures were 30-day and 1-year readmission rates, mortality, and risk factors for readmission and mortality. RESULTS: The effect sizes for readmission and mortality were estimated as the mean and 95% confidence interval (CI). The estimated 30-day and 1-year all-cause readmission rates were 0.19 (95% CI 0.14-0.23) and 0.53 (95% CI 0.46-0.59), respectively, while the all-cause mortality rates were 0.14 (95% CI 0.10-0.18) and 0.29 (95% CI 0.25-0.33), respectively. Comorbidities were highly prevalent in individuals with HF. CONCLUSION: Heart failure hospitalization is followed by high readmission and mortality rates.

Validation of the six-and-twelve criteria among patients with hepatocellular carcinoma and performance score 1 receiving transarterial chemoembolization.

BACKGROUND: Transarterial chemoembolization (TACE) is recommended for patients with intermediate hepatocellular carcinoma (HCC) according to treatment guidelines. However, a large number of patients with advanced HCC also receive TACE in clinical practice, especially for those with liver-confined HCC and Eastern Cooperative Oncology Group score (ECOG) 1. In view of previous studies, such patients have different prognoses from advanced HCC patients with macrovascular invasion or extrahepatic spread; therefore, patients with ECOG 1 alone might be classified into the intermediate stage and benefit from TACE treatment, but a study particularly focusing on such patients and exploring the effectiveness of TACE therapy is lacking. AIM: To investigate treatment outcomes of TACE in HCC patients with ECOG 1 alone and propose a specific prognostic model. METHODS: Patients from 24 Chinese tertiary hospitals were selected in this nationwide multicenter observational study from January 2010 to May 2016. Overall survival (OS) was estimated using Kaplan-Meier curves and compared by the log-rank test. Multivariate Cox regression was used to develop the potential prognostic models. The discriminatory ability of the models was compared and validated in various patient subgroups. The individual survival prediction for six-and-twelve (6&12) criteria, defined as the algebraic sum of tumor size (cm) and tumor number, was illustrated by contour plot of 3-year survival probability and nomogram. RESULTS: A total of 792 eligible patients were included. During follow-up, median OS reached 18.9 mo [95% confidence interval (CI): 16.9-21.0]. Three independent multivariate analyses demonstrated that tumor size, tumor number, α-fetoprotein level, albumin-bilirubin grade and total bilirubin were prognostic factors of OS (P < 0.05). The previously proposed 6&12 criteria was comparable or even better than currently proposed with the highest predictive ability. In addition, the 6&12 criteria was correlated with OS in various subgroups of patients. The patients were stratified into three strata with score ≤ 6, > 6 but ≤ 12, and > 12 with different median OS of 39.8 mo (95%CI: 23.9-55.7), 21.1 mo (95%CI: 18.4-23.8) and 9.8 mo (95%CI: 8.3-11.3), respectively (P < 0.001). CONCLUSION: TACE is effective for advanced HCC patients with ECOG 1 alone, and the 6&12 criteria may help with clinical decision-making.

Validation and evaluation of clinical prediction systems for first and repeated transarterial chemoembolization in unresectable hepatocellular carcinoma: A Chinese multicenter retrospective study.

BACKGROUND: The treatment outcome of transarterial chemoembolization (TACE) in unresectable hepatocellular carcinoma (HCC) varies greatly due to the clinical heterogeneity of the patients. Therefore, several prognostic systems have been proposed for risk stratification and candidate identification for first TACE and repeated TACE (re-TACE). AIM: To investigate the correlations between prognostic systems and radiological response, compare the predictive abilities, and integrate them in sequence for outcome prediction. METHODS: This nationwide multicenter retrospective cohort consisted of 1107 unresectable HCC patients in 15 Chinese tertiary hospitals from January 2010 to May 2016. The Hepatoma Arterial-embolization Prognostic (HAP) score system and its modified versions (mHAP, mHAP2 and mHAP3), as well as the six-and-twelve criteria were compared in terms of their correlations with radiological response and overall survival (OS) prediction for first TACE. The same analyses were conducted in 912 patients receiving re-TACE to evaluate the ART (assessment for re-treatment with TACE) and ABCR (alpha-fetoprotein, Barcelona Clinic Liver Cancer, Child-Pugh and Response) systems for post re-TACE survival (PRTS). RESULTS: All the prognostic systems were correlated with radiological response achieved by first TACE, and the six-and-twelve criteria exhibited the highest correlation (Spearman R = 0.39, P = 0.026) and consistency (Kappa = 0.14, P = 0.019), with optimal performance by area under the receiver operating characteristic curve of 0.71 [95% confidence interval (CI): 0.68-0.74]. With regard to the prediction of OS, the mHAP3 system identified patients with a favorable outcome with the highest concordance (C)-index of 0.60 (95%CI: 0.57-0.62) and the best area under the receiver operating characteristic curve at any time point during follow-up; whereas, PRTS was well-predicted by the ABCR system with a C-index of 0.61 (95%CI: 0.59-0.63), rather than ART. Finally, combining the mHAP3 and ABCR systems identified candidates suitable for TACE with an improved median PRTS of 36.6 mo, compared with non-candidates with a median PRTS of 20.0 mo (log-rank test P < 0.001). CONCLUSION: Radiological response to TACE is closely associated with tumor burden, but superior prognostic prediction could be achieved with the combination of mHAP3 and ABCR in patients with unresectable liver-confined HCC.

[Transjugular intrahepatic portosystemic shunt and combination with percutaneous transhepatic or transsplenic approach for the treatment of portal vein thrombosis with or without cavernomatous transformation].

OBJECTIVE: To evaluate retrospectively the feasibility, efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) or percutaneous transhepatic or transsplenic approach to the portal vein with the combination of TIPS for the treatment of patients with portal vein thrombosis with or without cavernous transformation. METHODS: Sixty-five patients with portal vein thrombosis from July 2002 to August 2007 at our hospital were analyzed retrospectively. Indirect portography through superior mesenteric artery was performed to determine the approaches for TIPS procedure. If the intrahepatic portal vein branches were visualized, TIPS was implemented directly from transjugular approach; if the intrahepatic portal vein branches failed to be visualized, an ultrasound-guided percutaneous transhepatic or transsplenic approach was performed to recanalize the thrombosed portal vein initially followed by TIPS placement to reconstruct the portal venous flow. Efficacy and complications were observed and revision and survival rates monitored during the follow-up. RESULTS: TIPS were successfully created in 54 of 65 patients with portal vein thrombosis with a success rate of 83.1%. Among them, TIPS were performed directly in 36 of 40 patients; portal vein recanalization were successfully performed via transhepatic access in 15 of 25 patients, and 3 of remaining 5 who failed the transhepatic approach were successfully done from transsplenic access. Then TIPS placement was accomplished with a success rate of 72.0% (18/25). The success rate in cirrhotic patients was 82.4% (42/51) and it was not significant different from those without cirrhosis 85.7% (12/14) (P = 0.766). While the success rate in the patients with cavernous transformation 71.8% (28/39) showed a significant difference compared to that without cavernous transformation 100% (26/26) (P = 0.002). The success rates in portal vein thrombosis and cavernous transformation with or without cirrhosis were 42.9% (18/42) and 83.3% (10/12) respectively, exhibiting a significant difference (P = 0.021). The mortality rate of 30 days post-operation was 3.7% (2/54). From Day 1 to 63 months follow-up, The incidence rate of hepatic encephalopathy was 27.8% (15/54); revision rate 22.2% (12/54); median survival time 31.4 months. CONCLUSIONS: Conventional TIPS or percutaneous transhepatic or transsplenic approach combined with TIPS for the treatment of portal vein thrombosis with or without cavernous transformation are feasible, safe and effective. It is essential to recanalize the thrombosed portal vein initially followed by TIPS placement to reconstruct the portal venous flow.

Upregulation of ZNRD1 enhances cisplatin resistance in human esophageal cancer cells by regulation of ERCC1 and Bcl-2.

BACKGROUND/AIMS: The precise mechanism of the zinc ribbon domain-containing-1 (ZNRD1) gene on cisplatin resistance remains unclear. The aim of this study is to identify the gene expression profile and explore the role of these genes in ZNRD1-induced cisplatin resistance in esophageal cancer cells. METHODS: An expression vector with ZNRD1 was transfected into the EC109 cells, and then cDNA microarray analysis was performed to identify the gene expression profile. The sensitivity of transfected EC109 cells to cisplatin was evaluated using the MTT assay. RT-PCR and Western blots were performed to validate the differential expression of genes identified by cDNA microarray analysis. RESULTS: We identified 16 genes with significantly different expression levels between the transfected and control cells. The tolerance of EC109 cells to cisplatin was significantly enhanced by the upregulation of ZNRD1. Furthermore, the expression of excision repair cross-complementing-1 (ERCC1) and B-cell lymphoma-2 (Bcl-2) was significantly upregulated. CONCLUSION: The ZNRD1 gene might be involved in the cisplatin resistance of EC109 cells by regulating the expression of ERCC1 and Bcl-2.

Downregulation of gasdermin D promotes gastric cancer proliferation by regulating cell cycle-related proteins.

OBJECTIVE: To explore the relationship between gasdermin D (GSDMD) and gastric cancer (GC) cell proliferation, and to determine whether the downregulated expression of GSDMD contributed to the tumorigenesis and proliferation of GC cells. METHODS: GSDMD expressions in GC tissues and matched adjacent non-cancerous tissues were assessed by quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry. The effect of GSDMD on cell proliferation in vitro was assessed by the colony formation assay and cell viability assays. In vivo, xenografted tumors in nude mice were evaluated. The cell cycle was analyzed by flow cytometry. In addition, the alterations of several cell cycle-related and cell signaling pathway proteins were analyzed by Western blot. RESULTS: GSDMD expression was decreased in GC, and the decreased expression of GSDMD could markedly promote the proliferation of tumors in vivo and in vitro. The downregulation of GSDMD accelerated S/G2 cell transition by activating extracellular signal regulated kinase, signal transducer and activator of transcription 3 and phosphatidylinositol 3 kinase/protein kinase B signaling pathways and regulating cell cycle-related proteins in GC. CONCLUSION: GSDMD may protect against cell proliferation of GC, and it may be used as a diagnostic and treatment strategy for GC.

Long non-coding RNAs AC026904.1 and UCA1: a "one-two punch" for TGF-ß-induced SNAI2 activation and epithelial-mesenchymal transition in breast cancer.

Transforming growth factor-ß (TGF-ß) has received much attention as a major inducer of epithelial-mesenchymal transition (EMT) during cancer progression, mainly by activating a set of pleiotropic transcription factors including SNAI2/Slug. However, the involvement of long non-coding RNAs (lncRNAs) in TGF-ß-induced Slug activation and EMT remains largely unknown. Methods: In this study, we used microarray analysis to compare lncRNA expression profiles between TGF-ß treated and untreated breast cancer cells. Then, the clinical significance of lncRNAs in breast cancer was investigated by qPCR and Kaplan-Meier survival analysis. The molecular mechanisms and EMT-promoting effects in vitro were analyzed by confocal laser microscopy, Western blotting, chromosome conformation capture (3C), chromatin isolation by RNA purification (ChIRP), ChIP, luciferase reporter assay and transwell migration assay. Lastly, the pro-metastatic effects in vivo were evaluated by bioluminescent imaging and hematoxylin and eosin (H&E) staining. Results: We observed that TGF-ß induced genome-wide changes in lncRNA levels in breast cancer cells, among which AC026904.1 and UCA1 were highly expressed in metastatic breast cancer and closely associated with poor prognosis. Mechanistic study revealed that AC026904.1 and UCA1 were upregulated by non-canonical and canonical TGF-ß pathways, respectively. Further analysis showed that AC026904.1 functions as an enhancer RNA in the nucleus, whereas UCA1 exerts a competitive endogenous RNA (ceRNA) activity in the cytoplasm. In addition, the biological functions of these two lncRNAs converged on the activation and maintenance of Slug, constituting a one-two punch in promoting EMT and tumor metastasis. Conclusion: These findings uncover for the first time that AC026904.1 and UCA1 could cooperatively upregulate Slug expression at both transcriptional and post-transcriptional levels, exerting critical roles in TGF-ß-induced EMT. The present work provides new evidence that lncRNAs function as key regulators of EMT and hold great promise to be used as novel biomarkers and therapeutic targets for metastatic breast cancer.

[MDR-reversing effect of short peptide binding specifically to multidrug-resistant gastric cancer cells].

OBJECTIVE: To investigate the binding effect of the short peptide SY1 to the multidrug-resistant gastric cancer cell line SGC7901/VCR cells and its reversing effect on those cancer cells. METHODS: The cultured cells were divided into two groups named SGC7901 and SGC7901/VCR. The SGC7901/VCR group was co-cultured with vincristine (VCR). SY1 was obtained from cyclic 7-mer peptide library by differential screening. Immunofluorescence technique was used to detect the capacity of SY1-containing positive phage specifically binding to SGC7901/VCR cells, compared with that of the negative phage and unrelated phage. MTT assay in vitro was performed to analyze the alteration of drug resistance of SGC7901/ VCR cells, using the positive phages and the chemically synthesized SY1 peptide. Flow cytometry assay was performed to detect the accumulation and retention of adriamycin (ADM) in the SGC7901/VCR cells. RESULTS: Immunofluorescence analysis showed that the SY1-containing positive phages could bind to the SGC7901/VCR cell surface but not to its parent cell line SGC7901 cells. The unrelated phage and negative phage did not bind to SGC7901/VCR cells. These results indicated that SY1 could specifically bind to SGC7901/VCR cells. MTT assay in vitro showed that the survival rate of SGC7901/VCR cells was reduced considerably by the positive phages and the chemically synthesized SY1 peptide (P <0. 05), indicating that SY1 enhanced the sensitivity of SGC7901/VCR cells to chemotherapeutic drug VCR. Flow-cytometric detection showed that SY1 enhanced the accumulation of ADM in the SGC7901/VCR cells, compared with that of the negative phages and the unrelated phages (P <0.05). CONCLUSION: SY1 not only is able to bind to SGC7901/VCR cells specifically, but also can partly reverse the resistance of SGC7901/VCR cell line to chemotherapeutic drug VCR. Those findings might be important to open a new approach to reverse the gastric cancer MDR.