406935

MIR143

epithelial-mesenchymal transition (EMT) plays a pivotal role in the development of cancer invasion and metastasis. Many studies have significantly enhanced the knowledge on EMT through the characterization of microRNAs (miRNAs) influencing the signaling pathways and downstream events that define EMT on a molecular level. In this study, we found that miR-143 suppressed EMT. Up-regulating miR-143 enhanced E-cadherin-mediated cell-cell adhesion ability, reduced mesenchymal markers, and decreased cell proliferation, migration, and invasion in vitro. In vivo, the xenograft mouse model also unveiled the suppressive effects of miR-143 on tumor growth. Additionally, we demonstrated that up-regulating extracellular signal regulated kinase 5 (ERK5) was associated with poor prognosis of breast cancer patients. Moreover, we observed an inverse correlation between miR-143 and ERK5 in breast cancer tissues. miR-143 directly targeted seed sequences in the 3'-untranslated regions of ERK5. Furthermore, we revealed that the downstream molecules of glycogen synthase kinase 3 beta (GSK-3beta)/Snail signaling were involved in EMT and modulated by ERK5. In summary, our findings demonstrated that miR-143 down-regulated its target ERK5, leading to the suppression of EMT induced by GSK-3beta/Snail signaling of breast cancer. (c) 2015 Wiley Periodicals, Inc.CI - (c) 2015 Wiley Periodicals, Inc.

BACKGROUND/AIMS: Early metastasis plays a pivotal role in tumor-caused death in gallbladder cancer (GBC) patients. Increasing evidence suggest that miR-143-5p is an active player involved in cancer metastasis and a potential therapeutic target. However, its role in the development of GBC cells remains unclear. The aim of this study is to reveal the inhibiting effects of miR-143-5p on the proliferation and metastasis in GBC. METHODS: Quantitative real-time PCR were used to investigate miR-143-5p and its target HIF-1alpha mRNA levels. Protein expression was measured by immunohistochemistry and western blot. The function and regulation mechanism of miR-143-5p was confirmed by MTS, colony formation, wound healing, transwell, and luciferase reporter assays. RESULTS: miR-143-5p was first found significantly reduced in GBC tissues compared with corresponding noncancerous gallbladder tissues. In addition, miR-143-5p deficiency correlated well with larger tumor size, advanced TNM stage, and poorer survival rate. In vitro, miR-143-5p addition dramatically suppressed GBC cells proliferation, migration and invasion, whereas miR-143-5p antisense led the opposite effects. Further elucidating the molecular mechanism inside, we found miR-143-5p exerted its inhibitory function through downregulating the expression of HIF-1alpha, which further reduced Twist1 and impeded epithelial-mesenchymal transition (EMT). CONCLUSIONS: Altogether, our studies identified a novel regulator, miR-143-5p, implicated in GBC prognosis through targeting HIF-1alpha/EMT related signaling pathway, which could serve as a biomarker and therapeutic target for GBC.CI - (c) 2017 The Author(s). Published by S. Karger AG, Basel.

Metastasis is a major clinical obstacle responsible for the high mortality and poor prognosis of gastric cancer (GC). MicroRNAs (miRNAs) are critical mediators of metastasis that act by modulating their target genes. In this study, we found that miR-143 and miR-145 act via a common target gene, MYO6, to regulate the epithelial-mesenchymal transition (EMT) and inhibit metastasis. We determined that miR-143 and miR-145 were downregulated in GC, and the ectopic expression of miR-143 and/or miR-145 inhibited GC cell migration and metastasis. Furthermore, MYO6 was identified as a direct common target of miR-143 and miR-145 and was elevated in GC. Silencing of MYO6 resulted in a metastasis-suppressive activity similar to that of miR-143 and miR-145, while restoring MYO6 attenuated the anti-metastatic or anti-EMT effects caused by miR-143 and miR-145. Clinically, an inverse correlation was observed between miR-143/145 levels and MYO6 levels in GC tissues, and either miR-143/145 downregulation or MYO6 upregulation was associated with more malignant phenotypes in patients with GC. In conclusion, miR-143 and miR-145 suppress GC cell migration and metastasis by inhibiting MYO6 expression and the EMT, which provides a novel mechanism and promising therapeutic target for the treatment of GC metastasis.