The pathways for Romidepsin-induced apoptosis and cell cycle arrest in HCC cells.
The aim of the study is to demonstrate the effect of Romidepsin in hepatocellular carcinoma (HCC) by inducing G2/M phase arrest via Erk/cdc25C/cdc2/cyclinB pathway and apoptosis through JNK/c-Jun/caspase3 pathway in vitro and in vivo. Human HCC cell lines were cultured with Romidepsin and DMSO (negative control) and 5-fluorouracil (positive control). Then the cells’ viability and apoptosis were determined by cell proliferation assay and flow cytometry. Protein concentrations and expression changes were measured by Western blot. Subsequently, Huh7 cells were subcutaneously inoculated into the nude mice, which were employed to further probe the tumor-suppressive effect of Romidepsin in vivo. Romidepsin treatment led to a time- and dose-dependent induction of cell cycle arrest in the G2/M phase and apoptosis. G2/M phase arrest inhibited the proliferation of HCC cells by alterations in p21/cdc25C/cdc2/cyclinB proteins. Increased concentrations of Erk and JNK phosphorylations were observed in a dose-dependent manner in the Romidepsin group, but p38 phosphorylation was not affected. G2/M phase arrest and the apoptosis of HCC cells induced by Romidepsin were mediated by the activation of Erk/MAPK pathways and JNK/MAPK pathways. The tumor size was significantly larger in the negative control group compared to Romidepsin group and no significant loss in body weight was observed in the Romidepsin group. Our findings offer proof-of-concept for use of Romidepsin as a novel class of chemotherapy in the treatment of HCC.