[Pilot study on the mechanisms of growth inhibitory effect of cinobufagin on HeLa cells].
OBJECTIVE
To study the effect of cinobufagin (CBG) on HeLa cell proliferation, and to analyze its mechanism.


METHODS
Proliferation inhibition in vitro was evaluated by MTT and Sulforhodamine B (SRB) assays in several human tumor cell lines, including Bel-7402, HeLa, MCF-7, BGC-823 and HL60. The cycle of HeLa cells was analyzed by flow cytometry. Two-dimensional electrophoresis was applied to analyze the influence of CBG on HeLa cell proteomics.


RESULTS
CBG had inhibitory effects on proliferation of five human cancer cell lines, and the IC(50) values were 0.011 micromol/L (Bel-7402), 0.019 micromol/L (HeLa), 0.116 micromol/L (MCF-7), 0.149 micromol/L (BGC-823) and 1.369 micromol/L (HL60), respectively. HeLa and Bel-7402 cells were among the most sensitive. Flow cytometry assay indicated that the treatment of HeLa cells with various concentrations of CBG for 72 h was able to increase the cell number at G(2)/M phase, from 17.3% up to 35.6%. The results of two-dimensional electrophoresis showed that treatment of HeLa cells with 0.02 micromol/L CBG for 48 h resulted in apparent changes of certain small molecular weight (30,000 - 90,000) acidic proteins (pH 4 - 6).


CONCLUSIONS
Cinobufagin has significant inhibitory effect on growth of five human cancer cells in vitro. It may lead to cell cycle arrest of HeLa cells at G(2)/M phase. It can also change the expression of some small molecular acidic proteins in HeLa cells.
National Research Laboratory of Natural and Biomimetic Drugs, Peking University Health Science Center, Beijing, 100083 China.
Li
L
Wang
Jun
J
Wu
Min
M
Li
Xiu-wei
XW
Yang
Jing-rong
JR
Cui
D000970:Antineoplastic Agents / Q000494:pharmacology*; D002018:Bufanolides / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D008419:Materia Medica; D010865:Pilot Projects
D000970:Antineoplastic Agents; D002018:Bufanolides; D004365:Drugs, Chinese Herbal; D008419:Materia Medica; C002471:cinobufagin