全反式维甲酸对骨肉瘤细胞OS732生长的影响

Effect of retinoic acid on growth of osteosarcoma cell line OS732

目的观察全反式维甲酸(all-trans-retinoicacid,ATRA)对骨肉瘤细胞OS732生长的影响,并探讨其作用的分子机制。方法用10-5MATRA作用骨肉瘤细胞OS732,6d后,进行细胞形态学观察、活细胞计数、流式细胞仪分析细胞周期、半定量RT-PCR检测细胞周期调控蛋白CyclinD(D1、D2、D3)、CDK4、P21WAF1mRNA表达的改变。结果ATRA作用后,OS732细胞胞浆展开,细胞核变小,核浆比例变小;瘤细胞生长减慢,细胞计数为正常对照组的39.5%;G0/G1期细胞明显增多,S期细胞减少,细胞阻滞于G0/G1期;CyclinD1、CyclinD2、CDK4mRNA表达均下降,尤以CyclinD2、CDK4下降最明显,CyclinD3、P21WAF1mRNA未见明显改变。结论10-5M全反式维甲酸可明显抑制骨肉瘤细胞OS732的增殖,并使细胞周期出现G1/G0期阻滞,该作用可能与维甲酸处理后OS732细胞中CyclinD2、CDK4表达的下调以致低磷酸化pRb积累有关。

[Objective] To investigate the effect of all-trans retinoic acid（ATRA） on the growth of osteosareoma cell line OS732 and its molecular machenism. [Methods] OS732 was treated with 10^-5MATRA for 6 days, then we observed cell morphology, counted cell number, analyzed cell cycles by flow cytometry and detected mRNA expressions of cyclinD（D1, D2, D3）, CDK4, P21^WAF1 by semi-quantity RT-PCR. [Results] Treatmed with 10^-5MATRA, The nucleus of OS732 cells became small and condensed, and cytoplasms expanded. So, the nucleocytoplasmic ratio decreased. 10^-5MATRA significantly suppressed the proliferation of os732 with only 39.5% cells when compared with untreated cells. Cells in G1 phase increased significantly, and the number of S phase decreased. Expressions of cyclinDl, cyclimD2 and CDK4 mRNA declined, especially cyclinD2 and CDK4. However, expressions of cyclinD3 and P21^WAF1 mRNA changed little. [Conclusions] 10^-5MATRA can significantly inhibit the growth of osteosareoma cell line OS732, and arrest cells in G0/G1 phase. The effects may due to the down-regulation of cyclinD2 and CDK4 which contribute to the hypophosphorylation of pRb.