PTEN对15-deoxy-PGJ2调节肝癌细胞生长作用的影响

Effects of PTEN on the 15-deoxy-PGJ2-mediated inhibition of the proliferation of hepatocellular carcinoma cells

目的:探讨过氧化物酶体增殖物激活受体γ(PPARγ)在肝癌细胞生长中的调节作用,以及PTEN和磷酸化Akt(pAkt)在该过程中的变化,旨在进一步揭示PPARγ调节肝癌细胞生长的机制。方法:培养SMMC-7721肝癌细胞,经不同浓度的PPARγ配体15-脱氧-前列腺素J2(15-deoxy-PGJ2)作用不同时间后,用MTT法测定细胞活力;用流式细胞仪进行细胞周期分析;用RT-PCR检测PPARγ配体对细胞PTENmRNA表达的影响;用Westernblot检测PPARγ配体对细胞PTEN和pAkt蛋白表达的影响。结果:15-deoxy-PGJ2对肝癌细胞的增殖具有抑制作用,且呈时间和剂量依赖性;它能增加G0/G1期细胞的比例,减少S期细胞的比例;增加SMMC-7721细胞PTENmRNA和蛋白的表达,减少pAkt蛋白的表达。结论:PPARγ的配体15-deoxy-PGJ2能够时间和剂量依赖性地抑制肝癌细胞的增殖,其机制可能是部分通过上调PTEN的表达而实现的。

Objective： To study the effects of peroxisome proliferators-activated receptor （PPAR）γ on the proliferation of human hepatocellular carcinoma cells and explore the role of phosphatase and tensin homologue deleted on chromosome ten （PTEN） and phospho-Akt（pArt） in this process. Methods： SMMC-7721 cells were treated with the ligand of PPARγ, 15-deoxy-PGJ2,at different concentrations for different periods. The proliferation of SMMC-7721 cells was assessed by MTT assay. The cell cycle was analyzed by flow cytometry. Expression of PTEN and pAkt in SMMC-7721 cells, which were treated with 15-deoxy-PGJ2 at different concentrations, were detected by RT-PCR and western blot. Results： MTT assay demonstrated that 15-deoxy-PGJ2 had an inhibitory effect on the proliferation of SMMC-7721 cells in a time- and dose- dependent manner. There were more cells arrested in G0/G1 phase analyzed by flow cytometry. RT-PCR demonstrated that the expression of PTEN mRNA in 15-deoxy-PGJ2-treated cells was up-regulated. Western blot demonstrated that the expression of PTEN was increased and pAkt was decreased. Conclusion： The ligand of PPARγ, 15-deoxy-PGJ2, could inhibit the proliferation of SMMC-7721 in a time-and dose-dependent manner. The mechanism may be associated with up-regulation of PTEN expression.