miR-515-5p suppresses HCC migration and invasion via targeting IL6/JAK/STAT3 pathway.

MicroRNAs (miRNAs) have been identified as critical modulators of cell migration and invasion, which are the major causes of cancer progression including hepatocellular carcinoma (HCC). However, the accurate role of miR-515-5p in HCC is still uncertain. Here, we report that miR-515-5p expression is down-regulated in HCC tissues and cell lines, and associated with absence of capsule formation (p = 0.015)﹑microvascular invasion(p = 0.003)﹑and advantange TNM stage (II-III) (p = 0.014) in HCC patients. Overexpression of miR-515-5p inhibited migration and invasion of HCC cells in vitro and in vivo, while miR-515-5p knockdown has the inverse effect. Moreover, using miRNA databases and dual-luciferase report assay, we find miR-515-5p directly binds to the 3'-untranslated region (3'-UTR) of interleukin 6 (IL6). In addition, the regulatory association between miR-515-5p and the IL-6/Janus kinase (JNK)/signal transducer and activator of transcription-3 (STAT3) signaling pathway was explored. Furthermore, overexpression of miR-515-5p inhibited the activation of the JAK/STAT3 signaling pathway, which was rescued by overexpression of IL-6. The results of the current study indicate that miR-515-5p overexpression may serve an important role in inhibiting migration and invasion of HCC cells via suppression of IL-6/JAK/STAT3 signaling pathway activation. MiR-515-5p may serve as a potential therapeutic target for HCC.

MicroRNA-520f-3p inhibits proliferation of gastric cancer cells via targeting SOX9 and thereby inactivating Wnt signaling.

MicroRNAs (miRNAs) are known to be important in a variety of cancer types. The specific expression and roles of miR-520f-3p in the context of gastric cancer (GC), however, remains unknown. Herein we determined miR-520f-3p expression to be significantly reduced in human GC cells compared to cells of the gastric epithelium, with comparable down-regulation also being evident in gastric cancer tissue samples and the low expression of this miRNA was positively correlated with features of more aggressive large tumor size (p = 0.019), depth of invasion (p = 0.008), and distant metastasis (p = 0.037). We further found that lower levels of miR-520f-3p corresponded with poorer GC patient overall (p = 0.003) and disease-free (p = 0.036) survival. When over-expressed in GC cells, miR-520f-3p was able to impair their growth, proliferation, and survival, instead leading to the induction of apoptosis. We further found that miR-520f-3p was able to bind the SOX9 3'-UTR, thereby negatively regulating its expression in GC cells. Consistent with this model, SOX9 and miR-520f-3p expression were negatively correlated with one another in GC tissues. When SOX9 was upregulated, this was also able to abrogate miR-520f-3p-mediated inactivation of Wnt/ß-catenin signaling. Together our findings thus suggest that miR-520f-3p can act to suppress GC progression, at least in part via suppressing SOX9 expression and thus disrupting Wnt/ß-catenin signaling. Our results thus highlight potential novel therapeutic targets in GC worthy of future investigation.

MicroRNA-212-3p inhibits the Proliferation and Invasion of Human Hepatocellular Carcinoma Cells by Suppressing CTGF expression.

MicroRNA-212-3p inhibits several human cancers but its effects on hepatocellular carcinoma (HCC) remain unclear. In this study, we show that miR-212-3p is down-regulated in HCC cell lines and tissues, and correlates with vascular invasion (p = 0.001), and the absence of capsule formation (p = 0.009). We found that miR-212-3p influenced the epithelial to mesenchymal transition (EMT) of HCCLM3 and Huh7 cells. Mechanistically, miR-212-3p repressed cell invasion through the suppression of connective tissue growth factor (CTGF). We therefore validate the anti-HCC effects of miR-212-3p through its ability to suppress CTGF and subsequent EMT.

MicroRNA-197-3p acts as a prognostic marker and inhibits cell invasion in hepatocellular carcinoma.

MicroRNAs (miRNAs) serve an important regulatory role in carcinogenesis and cancer progression. Aberrant expression of miR-197-3p has been reported in various human malignancies. However, the role of miR-197-3p in the progression and prognosis of hepatocellular carcinoma (HCC) remains unknown. The present study demonstrated that miR-197-3p was downregulated in HCC tissues and that the low level of miR-197-3p expression in HCC tumours correlated with aggressive clinicopathological characteristics; thus, miR-197-3p may serve as a predictor for poor prognosis in patients with HCC. Additionally, miR-197-3p markedly inhibited the metastasis of HCC cells in vitro and in vivo. Bioinformatics analysis further identified zinc finger protein interacted with K protein 1 (ZIK1) as a novel target of miR-197-3p in HCC cells. These findings suggest that miR-197-3p may regulate the survival of HCC cells, partially through the downregulation of ZIK1. Therefore, the miR-197-3p/ZIK1 axis may serve as a novel therapeutic target in patients with HCC.