MicroRNA-195 functions as a tumor suppressor by inhibiting CBX4 in hepatocellular carcinoma

MicroRNA-195 (miR-195) plays important roles in tumor metastasis and angiogenesis, yet its function and mechanism of action in hepatocellular carcinoma (HCC) remain to be elucidated. In this study, we aimed to confirm whether chromobox homolog 4 (CBX4) is a direct target gene of miR-195 and determine the functions of miR-195 through the CBX4 pathway. miR-195 expression was slightly lower in the HCC tissues compared with that in the adjacent normal tissues. In addition, western blotting and qRT-RCR results showed that both CBX4 mRNA and protein levels were downregulated upon miR-195 overexpression. Luciferase reporter assays revealed that CBX4 is a direct target gene of miR-195. Furthermore, overexpression of CBX4 significantly restored the proliferative, invasive and migratory capacities of the HepG2 cells. Finally, in vivo experiments confirmed that high expression of CBX4 in HepG2 cells promoted tumor growth. In conclusion, our study demonstrated that miR-195 acts as a tumor suppressor by directly targeting CBX4 in HCC. This finding suggests a potential novel strategy for therapeutic interventions of this disease.