MiR-769-5p expression is obviously up-regulated in HCC.
•
The elevated expression of miR-769-5p is correlated with poor prognosis.
•
MiR-769-5p contributes to the growth and metastasis of HCC cells.
•
RYBP is a novel downstream target of miR-769-5p.
•
RYBP partially mediates the oncogenic role of miR-769-5p in HCC.
Abstract
Hepatocellular carcinoma (HCC) is the commonest primary liver cancer with highly aggressive features. MicroRNAs (miRNAs) are demonstrated to play important roles in the tumorigenesis and progression of HCC. miR-769-5p is a recently identified cancer-associated miRNA. But, the expression level of miR-769-5p and its function in HCC are unexplored. In this study, we found that miR-769-5p expression was obviously increased in HCC samples compared to adjacent noncancerous liver tissues. Additionally, we revealed that miR-769-5p was over-expressed in HCC cells as compared with LO2 cells. Notably, HCC tissues from patients with tumor size ≥5 cm, venous infiltration and advanced tumor stages showed higher levels of miR-769-5p compared to those from corresponding controls. Interestingly, our data indicated that HCC patients highly expressing miR-769-5p had significant shorter survivals. Next, functional experiments verified that miR-769-5p knockdown markedly suppressed HCC cell proliferation, migration and invasion. Conversely, ectopic expression of miR-769-5p promoted these biological behaviors of Hep3B cells. Furthermore, depletion of miR-769-5p repressed the growth and metastasis of HCCLM3 cells in vivo. Importantly, miR-769-5p inversely modulated RING1 and YY1 binding protein (RYBP) by directly binding to 3’ untranslated region (UTR) in HCC cells. The expression of RYBP mRNA was down-regulated in HCC tissues and negatively correlated with miR-769-5p level. RYBP overexpression remarkably inhibited the proliferation, migration and invasion of HCCLM3 cells. Accordingly, knockdown of RYBP partially abolished miR-769-5p silencing-induced tumor suppressive effects on HCCLM3 cells. In summary, our study revealed the up-regulated expression of miR-769-5p, which contributed to HCC progression possibly by targeting RYBP.
