miR-346 Promotes HCC Progression by Suppressing Breast Cancer Metastasis Suppressor 1 Expression

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. MicroRNA (miRNA), a class of noncoding single-stranded RNA molecules, is involved in regulating cancer cell proliferation, metastasis, migration, invasion, and apoptosis. We showed that the expression of miR-346 was significantly increased in HCC tissues and cell lines, compared with noncancerous controls, and was associated with poor prognosis. Overexpression of miR-346 promoted proliferation and inhibited apoptosis of SMMC-7721 cells, while knockdown of miR-346 significantly suppressed proliferation and induced apoptosis of HepG2 cells. Then we identified breast cancer metastasis suppressor 1 (BRMS1) as a direct target of miR-346 based on luciferase reporter assays. There was a negative correlation between miR-346 and BRMS1 expression at both the protein and mRNA levels. Furthermore, inhibition of BRMS1 expression reversed the tumor-suppression effects of miR-346 downregulation in HepG2 cells. These results indicate that miR-346 promotes HCC progression by regulating BRMS1 expression.