过氧化物酶体增生物激活受体γ激动剂对Raji细胞的增生抑制作用及其机制

Anti-proliferation effect of peroxisome proliferator-activated receptor γ agonist on Raji cells and its mechanism

目的探讨过氧化物酶体增生物激活受体γ（PPARγ）激动剂曲格列酮（TGZ）对白血病Raji细胞的增生抑制作用及其作用机制。方法以不同浓度的TGZ（0—60μmol／L）作用于体外培养的Raji细胞24、48、72h，应用MTT法检测细胞生长抑制率，流式细胞仪检测细胞凋亡率，琼脂糖凝胶电泳观察细胞凋亡时的DNA梯状条带，并应用免疫印迹法（Western Blotting）检测凋亡调节蛋白Bax、bcl-2及Survivin的变化。结果20μmol／L以上的TGZ可显著抑制细胞的生长及诱导细胞发生凋亡，呈现出明显的量效与时效关系，药物作用72h后在琼脂糖凝胶电泳上可见明显的DNA梯状条带。Western Blotting检测结果表明，药物作用48h后凋亡抑制蛋白bcl-2及Survivin的表达水平明显降低，而促凋亡蛋白Bax的表达水平显著升高。结论PPAR1激动剂TGZ能显著抑制Raji细胞的生长并诱导细胞发生凋亡，降低bcl-2、Survivin及升高Bax的表达水平是TGZ诱导细胞发生凋亡的重要作用机制之一。

Objective To investigate the anti-proliferation effect of peroxisome proliferator-activated receptor γ（PPARγ） agonist troglitazone （TGZ） on leukemic Raji cells and its mechanisms. Methods Raji cells in culture medium in vitro were given different concentrations of TGZ （0-60 μmol/L） for 24, 48 and 72 h. The inhibitory rates of the cells were measured by MTT assay, cell apoptotic rate was detected by flow cytometry （FCM）, agarose gel electrophoresis was used to observe the DNA ladder, and western blotting was used to analyzed the variation of apoptosis related proteins bcl-2, Bax and Survivin. Results TGZ （over 20 μmol/L） could inhibit the growth of Raji cells and cause apoptosis remarkably, the suppression was both in time-and dose-dependent manner. DNA ladder was observed after the cells treated by TGZ for 72 h, and western blotting analysis revealed that anti-apoptotic proteins Survivin and bcl-2 were decreased remarkably while pro-apoptotie protein Bax increased significantly after the cells were treated by TGZ for 48 h. Conclusion PPARγ agonist TGZ can inhibit the growth and induce apoptosis on Raji cells significantly, downregulating the expression of Survivin and bcl-2 as well as upregulating of Bax expression of Raji cells may be one of its most important mechanisms.