Purpose: Menatetrenone, a vitamin K2 analogue has shown potent antitumor effects against several cancer cell lines including hepatoeellular carcinoma (HCC) cells.Previously, we have reported the effect of vitamin K2 on HCC cells is via suppressing the cyclin D1 expression through the IKK/IkB/NF-kB pathway.PKC, one of upstream factor family in the IKK/IkB/NF-kB pathway, plays an important role in cells growth cycle.However, if the vitamin K2 can effect the PKC expression or activation has remained to be demonstrated, and therefore we investigated the relation between them in present study.Experimental design: HCC cells were treated with vitamin K2 firstly, and then 1h 12-O-tetradecanoyl phorbol-13 acetate (TPA) inducing.The expressions of phosphorylated PKC and general PKC proteins were determined through western blotting assay independently.Results: Vitamin K2 effected the phosphorylation of PKC alpha and episilon induced by TPA although precise phosphorylation targets are not yet known, meanwhile it did not effect the phosphorylation of PKC delta, in HCC cell lines.Conclusion: Vitamin K2 inhibits the growth of HCC cells via suppression ofcyclin D1 expression through the the IKK/IkB/NF-kB pathway activated by PKC.