Pilot study on the mechanisms of growth inhibitory effect of cinobufagin on HeLa cells / 中华肿瘤杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the effect of cinobufagin (CBG) on HeLa cell proliferation, and to analyze its mechanism.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>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.</p>