Smac对骨肉瘤细胞系Saos-2生长及耐药性的影响

目的：观察Smac表达对骨肉瘤细胞Saos-2生长和耐药性的影响。方法：构建smac和反义smac表达载体pcDNA-smac和pcDNA—anti-smac，G418筛选出分别稳定转染pcDNA—$mac和pcDNA—anti—$mac的骨肉瘤细胞Saos—2。利用流式细胞仪检测各转染细胞的细胞周期分布；绘制各细胞在6d内的生长曲线以观察各细胞生长情况的变化。同时采用MTT法检测各转染Saos—2细胞对依托泊苷的敏感性。结果：与转染空载体pcDNA3．0的Saos—2细胞相比，转染反义smac的Saos—2细胞G1／G0期比例升高，细胞生长自第4天起明显加快。转染smac的Saos—2细胞的细胞周期及生长曲线无明显差别；依托泊苷作用细胞后，与转染空载体pcDNA3．0的Saos—2细胞相比，转染反义smac的Saos—2细胞的存活率增高；而转染smac的Saos—2细胞的存活率降低。结论：抑制Smac在细胞中表达，可使Saos—2细胞生长加快，增强对依托泊苷的耐受性，Smac在细胞中的过表达可提高Saos—2对依托泊苷的敏感性。

Effects of Smac on growth and drug resistance of human osteosarcoma Saos-2 cells

Objective:To observe the effect of second mitochondria-derived activator of caspase(Smac) expression on the growth and drug resistance of the human osteosarcoma cell line Saos-2. Methods: The pcDNA-smac and pcDNA-anti-.smac vector were constructed and transfected into the Saos-2 cells. The pcDNA-smac, pcDNA-anti-smac and pcDNAS. 0 transfect-ed Saos-2 cells were obtained by G418 screening. The cell cycle of the transfecting Saos-2 tested by flow cytometry and the cell growth curves were mapped by cell counting. The sensitivity of Saos-2 cells to etoposide were detected by MTT method. Results: Compared with the control cells transfected with empty vector pcDNA3. 0, the transfecting percentage of the pcD-NA-anti-smac cell in the G|/G0 phase increased and its growth was accelerated. After treated with etoposide, the viability of the pcDNA-anti-smac transfected cell increased and the viability of the pcDNA-smac transfected cell decreased. There was little difference on the cell cycle and the cell growth between the pcDNA-smac transfected cells and the control cells. Conclusion: Inhibiting Smac expression in Saos-2 cells arrests the cell in G1/G0 and increases cell resistance to etoposide. Over-expression of Smac makes Saos-2 cell more sensitive to etoposide.