Oncogenic miR-23a in Pancreatic Ductal Adenocarcinogenesis Via Inhibiting APAF1.

BACKGROUND: miR-23a, which participates in invasion of pancreatic ductal adenocarcinoma cells into the mesothelial barrier, is a critical regulator in many cancers. It, however, is still unknown whether miR-23a regulates pancreatic cell proliferation and apoptosis or not. AIMS: We sought to investigate the role of miR-23a in regulation of pancreatic cell proliferation and apoptosis. METHODS: miRNA, mRNA, and protein expressions were determined by qRT-PCR and Western blot, respectively. Dual-luciferase reporter assay was used in detection for binding ability of miR-23a to APAF1. Ectopic miR-23a and APAF 1 were introduced to pancreatic cells, and their roles in proliferation and apoptosis were detected by MTT, colony formation, and apoptosis assays, respectively. RESULTS: Up-regulation of miR-23a and down-regulation of APAF 1 were found in pancreatic ductal cancer, respectively. miR-23a significantly inhibited the luciferase activity by targeting APAF 1 3'UTR. Ectopic miR-23a significantly suppressed the APAF 1 gene expression in pancreatic cancer cells. Similar to siAPAF1, miR-23a significantly promoted pancreatic cancer cell proliferation and repressed apoptosis. Furthermore, miR-23a inhibitor and exogenous APAF 1 could recover the effects. CONCLUSIONS: It is suggested that miR-23a, acting as an oncogenic regulator by directly targeting APAF 1 in pancreatic cancer, is a useful potential biomarker in diagnosis and treatment of pancreatic cancer.

Clinical outcome and prognostic factors of T4N0M0 colon cancer after R0 resection: A retrospective study.

BACKGROUND: Paradoxically, patients with T4N0M0 (stage II, no lymph node metastasis) colon cancer have a worse prognosis than those with T2N1-2M0 (stage III). However, no previous report has addressed this issue. AIM: To screen prognostic risk factors for T4N0M0 colon cancer and construct a prognostic nomogram model for these patients. METHODS: Two hundred patients with T4N0M0 colon cancer were treated at Tianjin Medical University General Hospital between January 2017 and December 2021, of which 112 patients were assigned to the training cohort, and the remaining 88 patients were assigned to the validation cohort. Differences between the training and validation groups were analyzed. The training cohort was subjected to multivariate analysis to select prognostic risk factors for T4N0M0 colon cancer, followed by the construction of a nomogram model. RESULTS: The 3-year overall survival (OS) rates were 86.2% and 74.4% for the training and validation cohorts, respectively. Enterostomy (P = 0.000), T stage (P = 0.001), right hemicolon (P = 0.025), irregular review (P = 0.040), and carbohydrate antigen 199 (CA199) (P = 0.011) were independent risk factors of OS in patients with T4N0M0 colon cancer. A nomogram model with good concordance and accuracy was constructed. CONCLUSION: Enterostomy, T stage, right hemicolon, irregular review, and CA199 were independent risk factors for OS in patients with T4N0M0 colon cancer. The nomogram model exhibited good agreement and accuracy.

MYCT1 represses apoptosis of laryngeal cancerous cells through the MAX/miR-181a/NPM1 pathway.

MYCT1 is an important gene known to regulate cell viability and apoptosis of laryngeal cancer cells. However, the underlying molecular mechanism remains unclear. Here, we show that MAX enhances the expression of miR-181a by directly binding to its promoter, whereas miR-181a targets NPM1 and suppresses its expression in laryngeal cancer cells. MYCT1 and miR-181a decrease cell viability and colony formation through enhanced apoptosis, whereas NPM1 displays opposite effects in laryngeal cancer cells. Their opposing functions are further supported by the findings (a) that miR-181a is down-regulated, while NPM1 is up-regulated in laryngeal cancer, and (b) that either inhibition of miR-181a or overexpression of NPM1 can revert the pro-apoptotic effects of MYCT1 on laryngeal cancer cells through extracellular and intracellular apoptotic pathways. Our data suggest that MYCT1 may synergistically interact with MAX as a co-transcription factor or a component of MAX transcriptional complex, to transcriptionally regulate the expression of miR-181a, which, in turn, decreases NPM1 expression at post-transcriptional levels, leading to enhanced apoptosis in laryngeal cancer cells. These factors may serve as potential targets for early diagnosis and treatment of laryngeal cancer.

CREB promotes laryngeal cancer cell migration via MYCT1/NAT10 axis.

PURPOSE: CREB, MYCY1 and NAT10 are involved in cancer cell migration. However, the relationship between these three proteins and their role in laryngeal cancer cell migration remains unknown. METHODS: Transient gene transfection was performed in laryngeal cancer cells. Bioinformatics analysis was used to predict the binding of CREB to MYCT1 promoter. Binding of CREB to the promoter of MYCT1 was monitored by luciferase reporter assay and chromatin immuno-precipitation method in vitro and in vivo, respectively. Real-time RT-PCR and Western bolt were applied to detect gene transcription and translation levels, respectively. Laryngeal cancer cell migration was assayed by transwell chamber experiment. RESULTS: CREB protein expression was significantly up-regulated in laryngeal cancer tissues and associated with cancer differentiation, tumor stage, and lymphatic metastasis. CREB inhibits MYCT1 expression by direct binding to its promoter. Meanwhile, MYCT1 has a negative impact on the NAT10 gene expression. Furthermore, CREB promotes NAT10 expression via down-regulating the MYCT1 gene expression. In addition, contrary to MYCT1, CREB and NAT10 enhanced laryngeal cancer cell migration. MYCT1 and NAT10 significantly rescued the effects of CREB and MYCT1 on Hep2 cell migration, respectively. CONCLUSION: CREB promotes laryngeal cancer cell migration via MYCT1/NAT10 axis, suggesting that CREB might be a potential prognostic marker in laryngeal cancer.

Association between the HOTAIR polymorphisms and cancer risk: an updated meta-analysis.

PURPOSE: LncRNA HOTAIR plays an important role in many cancer. Several studies have shown that some HOTAIR SNPs might be associated with tumor risk in case-control studies, but the results are inconsistent and inconclusive. Therefore, it is necessary to better evaluate association between the HOTAIR SNPs and the risk of cancer. RESULTS: rs920778, rs7958904 and rs874945 but not rs4759314 and rs1899663 loci were significantly related to cancer risk, among of which rs920778 and rs874945 increased and rs7958904 decreased cancer risk, respectively. Moreover, rs920778 is significantly susceptible in both Asian population and digestive cancer risks. MATERIALS AND METHODS: Data were collected from PubMed, Embase and Web of Science. A total of 11 case-control studies were selected for the quantitative analysis. Software Stata (Version 12) was used to calculate Odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate the strength of the associations. Subgroup analysis, sensitivity analysis, and publication bias were also performed. Five HOTAIR SNPs were finally enrolled in the study. CONCLUSIONS: HOTAIR SNP rs920778, rs7958904 and rs874945 are susceptible to cancer risk. SNP rs920778 is also a useful risk factor in evaluation of Asian population and digestive cancer. In addition, the cancer risk SNP rs874945 is first reported in the meta-analysis.

Transcriptional suppression of microRNA-27a contributes to laryngeal cancer differentiation via GSK-3ß-involved Wnt/ß-catenin pathway.

miR-27a regulates cell differentiation in a variety of diseases. However, whether and how miR-27a participates in laryngeal cancer cell differentiation remains unknown. Therefore, we explored role and molecular mechanism of miR-27a in laryngeal cancer differentiation in the study. We found that miR-27a expression was inversely correlated with laryngeal cancer differentiation degree based on the clinical pathological diagnosis of each patient. miR-27 asignificantly rescued differentiation and inhibited ß-catenin, LEF1, OCT4 and SOX2 in Wnt/ß-catenin pathway in all-trans-retinoic acid (ATRA)-induced laryngeal cancer cells. Bindings of RARα to miR-27a and miR-27a to GSK-3ß were confirmed by ChIP and Luciferase reporter assays, respectively. In conclusion, miR-27a is a negative regulator in laryngeal cancer differentiation. RARα-mediated miR-27a transcriptional inactivation releases the inhibition of miR-27a on GSK-3ß leading to laryngeal cancer differentiation through GSK-3ß-involved Wnt/ß-catenin pathway, suggesting that miR-27a is a usefully therapeutic target at least in ATRA-induced laryngeal cancer differentiation.

Methylation Status of SP1 Sites within miR-23a-27a-24-2 Promoter Region Influences Laryngeal Cancer Cell Proliferation and Apoptosis.

DNA methylation plays critical roles in regulation of microRNA expression and function. miR-23a-27a-24-2 cluster has various functions and aberrant expression of the cluster is a common event in many cancers. However, whether DNA methylation influences the cluster expression and function is not reported. Here we found a CG-rich region spanning two SP1 sites in the cluster promoter region. The SP1 sites in the cluster were demethylated and methylated in Hep2 cells and HEK293 cells, respectively. Meanwhile, the cluster was significantly upregulated and downregulated in Hep2 cells and HEK293 cells, respectively. The SP1 sites were remethylated and the cluster was significantly downregulated in Hep2 cells into which methyl donor, S-adenosyl-L-methionine, was introduced. Moreover, S-adenosyl-L-methionine significantly increased Hep2 cell viability and repressed Hep2 cell early apoptosis. We also found that construct with two SP1 sites had highest luciferase activity and SP1 specifically bound the gene cluster promoter in vitro. We conclude that demethylated SP1 sites in miR-23a-27a-24-2 cluster upregulate the cluster expression, leading to proliferation promotion and early apoptosis inhibition in laryngeal cancer cells.

High microRNA-23a expression in laryngeal squamous cell carcinoma is associated with poor patient prognosis.

BACKGROUND: MicroRNA-23a (miR-23a) has been demonstrated to play an important role in the development of several types of cancer, but its role in tumorigenesis of laryngeal carcinoma is still unclear. The aim of this study was to investigate the expression patterns and clinical implications of miR-23a in laryngeal cancer. METHODS: Quantitative RT-PCR was performed to evaluate the expression level of miR-23a in 52 pairs of laryngeal cancer. Analysis between miR-23a expression and clinical features of laryngeal carcinomas was performed by appropriate statistical methods. Role of miR-23a in laryngeal cancer cell migration and invasion was detected via transwell and matrigel assays, respectively. RESULTS: miR-23a was significantly up-regulated in laryngeal cancer tissues compared to normal adjacent laryngeal tissues (P < 0.01). Tumors with high miR-23a expression had significantly greater extent of lymph node metastasis (P < 0.01), worse clinical stage (P < 0.05) and shorter overall five-year survival (P < 0.01) than those with low miR-23a expression. Both univariate and multivariate Cox hazard regression analysis results showed that clinical stage and miR-23a expression were significantly correlated with patient five-year survival (P < 0.01). miR-23a overexpression also significantly promoted laryngeal cancer cell migration and invasion in vitro. CONCLUSIONS: miR-23a, an independent prognostic factor for laryngeal cancer, participates in the onset and progression of laryngeal cancer. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2021488014982305.