Effect of halofuginone on the inhibition of proliferation and invasion of hepatocellular carcinoma HepG2 cell line.

Primary liver cancer is a common cancer and the mortality of liver cancer ranks the second of all malignancy-related deaths in China. The most common primary liver cancer is hepatocellular carcinoma, accounting for approximately 90% of the total. Because liver is the largest parenchymatous organ in the body undertaking all kinds of important metabolic functions, liver cancer inevitably causes greater harms and its treatment is extremely difficult. Currently, there are still no effective drugs for the treatment of patients with advanced inoperable liver cancer. We observed the strong inhibitory activity of halofuginone on HepG2 cell growth and the cell cycle and apoptosis assays showed that halofuginone arrested the cell cycle and inhibited the induction. And we found that halofuginone inhibits tumor cell cycle possibly by up-regulating p15 and p21 of expression. Then, we found that the proportion of cleaved PARP, caspase-3, 8 and 9 in HepG2 cells increased after halofuginone treatment. And the results showed that halofuginone down-regulated Mcl-1 and c-IAP1 expression. Finally, our results showed halofuginone regulated the activities of JNK and MEK/ERK signaling pathways in hepatocellular carcinoma cells. In summary, this study shows that halofuginone can inhibit the in vitro growth, arrest the cell cycle and induce the apoptosis of HepG2 cells. Its mechanisms of action may be related to the regulation of associated protein expression, up-regulation of JNK, and inhibition of MEK/ERK signaling pathway.