Objective: To explore the effect of miR-135b on the invasion and metastasis of hepatocellular carcinoma cells and the underlying molecular mechanism.
Methods: The invasive and metastasis abilities were detected by Transwell(TM) assay in hepatocellular carcinoma cells with over-expressed or down-regulated miR135b. The hepatocellular carcinoma cell growth and tumor formation abilities in vivo were examined by xenograft model. Downstream genes targeted by miR-135b were detected by Western blotting and dual-luciferase report assay.
Results: Up-regulated miR-135b was observed in highly invasive MHCC97 hepatocellular carcinoma cell lines. Over-expression of miR-135b enhanced the invasive and migratory abilities in vitro and in vivo of HepG2 and Bel-7402 cells. The invasive and migratory abilities in vitro and in vivo were significantly suppressed in miR-135b down-regulated MHCC97 hepatocellular carcinoma cells silenced by the pcDNA-miR-135b-Sponge plasmid. Western blotting and dual-luciferase report system analysis showed that multiple key components in the Hippo pathway, including large tumor suppressor homolog 2 (LATS2), beta-transducin repeats-containing proteins (β-TrCP), N-myc downstream-regulated gene 2 (NDR2) as well as leucine zipper tumor suppressor gene 1 (LZTS1) were targeted by miR-135b.
Conclusion: miR-135b promotes the invasion and metastasis possibly by targeting the Hippo pathway genes.