Tanshindiol-C suppresses in vitro and in vivo hepatocellular cancer cell growth by inducing mitochondrial-mediated apoptosis, cell cycle arrest, inhibition of angiogenesis and modulation of key tumor-suppressive miRNAs.

PURPOSE: Hepatocellular carcinoma causes considerable mortality and no efficient chemotherapy is available. Novel molecules of plant origin may prove beneficial in the development of therapy of hepatocellular carcinoma. In this study we examined the anticancer effects of Tanshindiol-C (TC) against the hepatocellular carcinoma SNU-4235 cell line. METHODS: Proliferation rate of the SNU-2435 cells was determined by MTT assay. Apoptosis was confirmed by DAPI and annexin V/PI staining. Cell cycle analysis was performed by flow cytometry. MicroRNA expression was checked by qRT-PCR and protein expression by western blotting. The in vivo evaluation of TC was performed in xenografted mice models. RESULTS: TC inhibited the growth of the SNU-4235 cells and exhibited an IC50 of 20 µM. Investigation of the underlying mechanism revealed that TC triggered apoptotic death of the SNU-4235 cells which was also associated with enhancement of the expression of Bax and decrease in the expression of Bcl-2. TC also caused arrest of the cells in the G2/M phase of the cell cycle and also exerted angiogenitic effects. TC also enhanced the expression of the tumor suppressor microRNA-21, 222 and 31. In vivo evaluation of TC revealed that it could inhibit the tumor weight volume, suggestive of the anticancer potential of TC. CONCLUSIONS: In brief, tanshindiol-C exerts anticancer effects on hepatocellular carcinoma by induction of apoptosis and cell cycle arrest, along with inhibiting the angiogenesis and the expression of tumor suppressive microRNAs. TC could also inhibit the growth of the xenografted tumors and hence could prove to be a potential anticancer agent.