[Effect of rapamycin on leukemia cell lines]

This study was aimed to investigate the effect of rapamycin on proliferation and cell cycle of leukemic cell lines and to analyze the changes of mTOR mRNA expression before and after treatment with rapamycin. The leukemic cell lines KG1, K562 and U937 were treated with rapamycin of different concentrations. The MTT assay was used to detect the effect of rapamycin on proliferation of leukemic cell lines before and after treatment with rapamycin, the real-time quantitative PCR was used to investigate the expression of mTOR mRNA. The results indicated that the optimal effective concentration of rapamycin for KG1 was 20 nmol/L, showing significant inhibitive effect on cell growth, arrest of cells in G(0)/G(1) phase, obvious apoptosis of cells and significant decrease of mTOR mRNA expression level. As compared with KG1 cell lines, K562 and U937 did not show significant response to rapamycin. It is concluded that the rapamycin can inhibit cell proliferation. As compared with and the K562 and U937 cells, the KG1 cells are sensitive to rapamycin.