RESUMO
<p><b>OBJECTIVE</b>To observe the effects of deguelin on the proliferation of breast cancer MCF-7 cells and lung cancer H1299 cells in vitro and the expression of minichromosome maintenance protein 3 (MCM3) and CDC45 in the cells.</p><p><b>METHODS</b>MTT assay was used to evaluate the proliferation of MCF-7 and H1299 cells exposed to different concentrations of deguelin for 48, 72 or 96 h. The growth of the cells was observed microscopically and the changes of MCM3 and CDC45 expressions in MCF-7 and H1299 cells following deguelin treatment were detected with fluorescence quantitative PCR.</p><p><b>RESULTS</b>The proliferation of MCF-7 cells was significantly inhibited by exposure to 0.25, 0.5, 1, 5, 10, 30, and 50 µmol/L deguelin for 48, 72, and 96 h in a concentration- and time-dependent manner. In MCF-7 cells, the ICof deguelin at 48, 72, and 96 h was 9, 3, and 2 µmol/L, respectively. Deguelin treatments of H1299 cells at 0.5, 1, 5, 10, 30, 50, and 100 µmol/L also resulted in a concentration- and time-dependent inhibition of the cell growth with an ICat 96 h of 2 µmol/L. Optical microscopy of the cells revealed a decreased number of viable cells with obvious cell shrinkage following deguelin treatments. The expression of MCM3 and CDC45 were significantly reduced in the cells after deguelin treatments.</p><p><b>CONCLUSION</b>Deguelin can inhibit the proliferation of MCF-7 and H1299 cells in vitro and down-regulate the expression of MCM3 and CDC45 in the cells.</p>