title: Huaier polysaccharide induces apoptosis in hepatocellular carcinoma cells through p38 MAPK.
abstract: The underlying mechanism of the antitumor activity of Huaier polysaccharide (HP) remains to be explored. The present study aimed to investigate the inhibitory effect of HP on hepatocellular carcinoma (HCC) cells, and to explore the possible mechanisms of its anticancer effect. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, while apoptotic nuclear changes were observed using Hoechst 33258 staining. The distribution of cell cycle and apoptosis were analyzed by flow cytometry, and western blotting was used to test the apoptotic pathways. Apoptosis and mitogen-activated protein kinase (MAPK) inhibitors were used to investigate the mechanism of apoptosis. HP triggered cell cycle arrest and apoptosis in HepG2 and Huh7 cells. Both the extrinsic and intrinsic apoptotic pathways were activated after HP treatment. Furthermore, HP enhanced the three major MAPK pathways (extracellular signal-regulated kinase, c-Jun N-terminal kinase and p38 MAPK) and inhibited the AKT/mechanistic target of rapamycin signaling pathway in HCC cells. Notably, the inactivation of p38 MAPK impaired the HP-induced cell death. HP exerted its antitumor effect on HCC cells through the regulation of the expression of the apoptosis-related proteins B-cell lymphoma (Bcl)-2, Bcl-2-associated X protein and survivin. The present study provides evidence that HP induces apoptosis in HCC cells and demonstrated the role of p38 MAPK in HP-triggered cancer cell death.
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Haidong
authors.initials: H
authors.lastname: Bao
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.affiliation: Institute of Cancer Stem Cell, Dalian Medical University Cancer Center, Dalian, Liaoning 116044, P.R. China.
authors.forename: Ke
authors.initials: K
authors.lastname: Jiang
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Xianbin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Long
authors.initials: L
authors.lastname: Xie
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Zhongyu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Hepatobiliary Surgery, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116011, P.R. China.
authors.forename: Peng
authors.initials: P
authors.lastname: Gong
keywords: Huaier polysaccharide; apoptosis; hepatocellular carcinoma; mitogen-activated protein kinase; p38 MAPK