Blocking autophagy enhances the apoptosis effect of bufalin on human hepatocellular carcinoma cells through endoplasmic reticulum stress and JNK activation

Apoptosis. 2014 Jan;19(1):210-23. doi: 10.1007/s10495-013-0914-7.


Bufalin extracts are a part of traditional Chinese medicine, Chansu. In the current study, we investigated the effect of bufalin on the proliferation of the human hepatocellular carcinoma (HCC) cell lines, Huh-7 and HepG-2, and explored the therapeutic potential of the drug. Our results demonstrated that bufalin markedly inhibited cell proliferation and promoted apoptosis in the Huh-7 and HepG-2 cells in vitro. The underlying mechanism of the bufalin-induced apoptosis was the induction of endoplasmic reticulum (ER) stress via the IRE1-JNK pathway. In addition, during the ER stress response, the autophagy pathway, characterized by the conversion of LC3-I to LC3-II, was activated, resulting in increased Beclin-1 protein levels, decreased p62 expression and stimulation of autophagic flux. Our data supported the pro-survival role of bufalin-induced autophagy when the autophagy pathway was blocked with specific chemical inhibitors; the involvement of the IRE1 pathway in the ER stress-induced autophagy was also demonstrated when the expression of IRE1 and CHOP was silenced using siRNA. These data indicate that combining bufalin with a specific autophagy inhibitor could be a promising therapeutic approach for the treatment of HCC.

MeSH terms

  • Antineoplastic Agents, Phytogenic / pharmacology
  • Apoptosis / drug effects*
  • Autophagy / drug effects*
  • Bufanolides / pharmacology*
  • Carcinoma, Hepatocellular / drug therapy
  • Carcinoma, Hepatocellular / enzymology
  • Carcinoma, Hepatocellular / physiopathology*
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Down-Regulation / drug effects
  • Drugs, Chinese Herbal / pharmacology*
  • Endoplasmic Reticulum Stress / drug effects
  • Enzyme Activation / drug effects
  • Humans
  • Liver Neoplasms / drug therapy
  • Liver Neoplasms / enzymology
  • Liver Neoplasms / physiopathology*
  • MAP Kinase Kinase 4 / genetics
  • MAP Kinase Kinase 4 / metabolism*
  • Up-Regulation / drug effects


  • Antineoplastic Agents, Phytogenic
  • Bufanolides
  • Drugs, Chinese Herbal
  • MAP Kinase Kinase 4
  • bufalin