[Effect of bufalin-inducing apoptosis on Bcl-2 and PKC in HL-60 cells].

Abstract

Previous study revealed that bufalin can inhibit proliferation, and induce apoptosis in some human cancer cell lines. However, the mechanism of its anticancer effect has not been fully understood. The present study was designed to investigate the effects of bufalin-induced apoptosis on Bcl-2 and PKC in human leukemic HL-60 cells. The cell viability was determined by trypan blue dye exclusion. The apoptosis was detected by morphology, flow cytometry and DNA agarose gel electrophoresis. The expressions of Bcl-2 and PKC were analyzed by Western blot, and activity of PKC was assayed by [gamma-(32)P] isotope incorporation method. The results showed as follows: (1) proliferation of HL-60 cells was inhibited by bufalin and the IC(50) at 24, 48, 72 hours were (25.8 +/- 2.1), (8.0 +/- 1.2) and (2.3 +/- 0.3) nmol/L, respectively. (2) apoptosis of HL-60 cells was induced when the cells were treated with bufalin at concentration of 50 nmol/L for 24 hours. (3) compared with control, treatment with bufalin at concentration of 50 nmol/L for 6 - 24 hours resulted in downregulation of protein expression, decrease of phosphorylation, and cleavage of Bcl-2, simultaneously. (4) the activity of total PKC was unchanged when HL-60 cells were exposed to 1 - 100 nmol/L bufalin for 30 minutes, but PKCbetaII underwent translocation from cytosol to membrane. It is concluded that apoptosis induced by bufalin is associated with downregulation of protein expression, dephosphorylation, and cleavage of Bcl-2 in HL-60 cells.

• Authors: Xin Tian, Ping-Ping Wang, Yun-Peng Liu, Ke-Zuo Hou, Bo Jin, Ying Luo, Xiu-Juan Qu
• Journal: Zhongguo shi yan xue ye xue za zhi (Zhongguo Shi Yan Xue Ye Xue Za Zhi) Vol. 15 Issue 1 Pg. 67-71 (Feb 2007) ISSN: 1009-2137 [Print] China
• PMID: 17490524 (Publication Type: English Abstract, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Bufanolides
• Drugs, Chinese Herbal
• Materia Medica
• Proto-Oncogene Proteins c-bcl-2
• Protein Kinase C
• bufalin

Topics

• Apoptosis (drug effects)
• Bufanolides (pharmacology)
• Cell Proliferation (drug effects)
• Drugs, Chinese Herbal (pharmacology)
• HL-60 Cells
• Humans
• Materia Medica (pharmacology)
• Phosphorylation
• Protein Kinase C (biosynthesis, genetics)
• Proto-Oncogene Proteins c-bcl-2 (biosynthesis, genetics)