miR-145 suppresses cell invasion in hepatocellular carcinoma cells: miR-145 targets ADAM17.

AIM: miR-145 is a candidate tumor suppressor miRNA. However, it is unknown whether miR-145 is involved in the invasion of hepatocellular carcinoma (HCC). Therefore, we aimed to explore the effect and mechanism of miR-145 in the control of HCC cell invasion. METHODS: HCC cell invasion was evaluated by transwell assays after transfection with pre-miR-145 or anti-miR-145. A luciferase reporter assay was used to determine whether a disintegrin and metalloprotease 17 (ADAM17) were a target of miR-145. The levels of miR-145 and ADAM17 mRNA were detected by a real-time polymerase chain reaction assay, and the level of ADAM17 protein was measured by western blot analysis. Pearson's correlation test was used to assess the correlation between ADAM17 mRNA expression and miR-145 expression in 20 HCC tissue samples. RESULTS: miR-145 was significantly downregulated in HCC tissues and cell lines. The loss of miR-145 expression was associated with the tumor-node-metastasis stage, vascular invasion and intrahepatic metastasis. The overexpression of miR-145 was able to suppress tumor MHCC-97H cell invasion, whereas the knockdown of miR-145 expression induced SMMC-7721 cell invasion. We demonstrated that miR-145 bound directly to the 3'-untranslated region of ADAM17 and inhibited the expression of ADAM17. The knockdown of ADAM17 in SMMC-7721 cells could partially reverse the effects of anti-miR-145. miR-145 expression was inversely associated with ADAM17 expression in 20 HCC tissue specimens. CONCLUSION: Our findings indicate that miR-145 could inhibit HCC cell invasion by regulating the expression of ADAM17.