406969

MIR194-1

BACKGROUND: epithelial-mesenchymal transition (EMT) is the key process driving cancer metastasis. Oncogene/self renewal factor BMI-1 has been shown to induce EMT in cancer cells. Recent studies have implied that noncoding microRNAs (miRNAs) act as crucial modulators for EMT. The aims of this study was to determine the roles of BMI-1 in inducing EMT of endometrial cancer (EC) cells and the possible role of miRNA in controlling BMI-1 expression. METHODS AND RESULTS: We evaluated the expression of BMI-1 gene in a panel of EC cell lines, and detected a strong association with invasive capability. Stable silencing of BMI-1 in invasive mesenchymal-type EC cells up-regulated the epithelial marker E-cadherin, down-regulated mesenchymal marker Vimentin, and significantly reduced cell invasion in vitro. Furthermore, we discovered that the expression of BMI-1 was suppressed by miR-194 via direct binding to the BMI-1 3'-untranslated region 3'-UTR). Ectopic expression of miR-194 in EC cells induced a mesenchymal to epithelial transition (MET) by restoring E-cadherin, reducing Vimentin expression, and inhibiting cell invasion in vitro. Moreover, BMI-1 knockdown inhibited in vitro EC cell proliferation and clone growth, correlated with either increased p16 expression or decreased expression of stem cell and chemoresistance markers (SOX-2, KLF4 and MRP-1). CONCLUSION: These findings demonstrate the novel mechanism for BMI-1 in contributing to EC cell invasion and that repression of BMI-1 by miR-194 could have a therapeutic potential to suppress EC metastasis.

AIM: We hypothesized that miR-194 may control Forkhead box protein M1 (FoxM1) expression in gastric cancer cells and therefore may have therapeutic potential in gastric cancer. METHODS: The expression level of miR-194 was examined using real-time PCR in human gastric cancer and noncancerous gastric tissues, gastric cancer cell and normal gastric mucosal epithelial cell. We examined whether the miR-194 regulates cell migration and invasion, and the epithelial-mesenchymal transition Phenotype by inhibiting FoxM1 in gastric cancer cells. RESULTS: The expression of miR-194 was significantly lower in gastric cancer compared with non-cancerous gastric tissues and cells. Exogenous expression of miR-194 inhibited cell migration, invasion, and the epithelial-mesenchymal transition phenotype in gastric cancer cells. Moreover, we discovered a novel post-transcriptional regulatory mechanism of FoxM1 expression that is mediated by miR-194. CONCLUSION: Our study clearly demonstrates that miR-194 inhibits the acquisition of the EMT phenotype in gastric cancer cells by downregulating FoxM1, thereby inhibiting cell migration and invasion during cancer progression.

BACKGROUND/AIMS: Since the combined actions of lncRNAs and miRNAs have been considered to be involved in the occurrence and development of various neoplasms, the main purpose of this study was to discover whether and how lncRNA H19 and miR-194 influenced the epithelial-mesenchymal transition (EMT) process of colorectal adenocarcinoma (CRA). METHODS: Totally 214 pairs of CRA and adjacent normal tissues were collected, and 5 human CRA cell lines (i.e. HCT116, HT-29, RKO SW280 and Lovo) were purchased. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was adopted to quantify the H19 and miR-194-5p expressions in cells and tissues. The expressions of FoxM1, E-cadherin, vimentin, N-cadherin were determined using western blot. On the side, si-H19, si-NC, miR-194-5p mimic, miR-194-5p inhibitor and negative control (NC) were transfected into CRA cell lines. Meanwhile, the invasive, migratory and proliferative conditions of the cells were assessed through transwell, wound healing and colony-forming experiments, with final verification of the relationship between H19 and miR-194-5p employing dual-luciferase reporter gene assay. RESULTS: Highly-expressed H19, lowly-expressed miR-194-5p, low-grade differentiation and lymph node metastasis appeared as the independent predictors of unfavorable prognosis in CRA patients' (all P< 0.05). It indicated that FoxM1 expression displayed positive correlations with H19 expression, yet negative associations with miR-194-5p expression within CRA tissues (P< 0.05). In addition, transfection of H19-siRNA and miR-145-5p mimic triggered a conspicuous increase in E-cadherin expression, as well as an evidently down-regulation in vimentin and N-cadherin expressions within HT29 and RKO cells (P< 0.05). On the other hand, the invasive and migratory capacities of CRA cells were significantly hindered (P< 0.05). Moreover, the luciferase reporter gene assay confirmed that H19 modified miR-194-5p expression through directly targeting at it (P< 0.05). Ultimately, FoxM1 could reverse the role of miR-194-5p in inhibiting invasion, migration and EMT of CRA cells (P< 0.05). CONCLUSION: LncRNA H19/miR-194/FoxM1 axis could serve as a profound target for the diagnosis and treatment of CRA.CI - (c) 2018 The Author(s). Published by S. Karger AG, Basel.