The Growth Inhibitory Effects Of Sirolimus On RCC 786-O Cell Line In Vitro

ObjectivesIn this paper, the growth inhibiting effects of sirolimus on renal cell carcinoma 786-O cells in vitro were studied.Methods1. Human RCC 786-O cells were cultured in RPMI 1640 medium supplemented with 10% fetal bovine serum, and at 37℃in a 5% CO2/95% humidified air atmosphere. Cells were subcultured every three days.2. MTT assay was used to assess the anti-proliferation effects on 786-O cells. Cells were harvested when grew reached 70% to 80% confluence, plated in 96-well plate for 2000cells/well, and incubated at 37℃in a 5% CO2/95% humidified air atmosphere. Different concentration of sirolimus were added 48 hours prior to cell harvest.3. Flow cytometry was used for cell cycle analysis. 786-O cells were treated with 12.5nmol/l sirolimus for 24 hours, 106 cells were collected, and washed with phosphate-buffered saline and resuspended for flow cytometry study.4. RT-PCR assay was used to analyze the expression of MDR1 and Survivin mRNA. 786-O cells were treated with different concentration of sirolimus for 24 hours, harvest cells for RT-PCR assay.Results1. The growth of human 786-O cells were inhibited by sirolimus(P﹤0.05), and the inhibiting effects was enhanced by a higher drug concentration(P﹤0.05).2. Cell cycle arrested at G1 phase was observed by flow cytometry analysis(P﹤0.01), sirolimus did not induce apoptosis of RCC 786-O cells.3. Sirolimus reduce the levels of MDR1 and Survivin mRNA(P﹤0.01), and the reduce effects was enhanced by a higher drug concentration(P﹤0.01).ConclusionsOur research demonstrates that sirolimus can inhibit the growth of human 786-O cells, and the inhibiting effects was enhanced by a higher drug concentration. Sirolimus arrest the cell growth cycle at G1 phase, but do not induce apoptosis. Sirolimus down-regulate the expression of MDR1 and Survivin mRNA, and the down-regulation effect was enhanced by a higher drug concentration.