拓扑异构酶2α受抑癌基因p53的调控并调节前列腺癌细胞的增殖能力

TOP2α,a novel p53 target gene,regulates proliferation of prostate cancer cells

目的观察TOP2α对前列腺癌细胞增殖能力的影响以及抑癌基因p53对TOP2α的调控能力。方法以Lipofectamine2000试剂转染针对p53和非特异性对照组的siRNA,干扰前列腺癌细胞C4-2中p53的表达,采用Realtime PCR和Western Blot检测细胞内TOP2α的mRNA和蛋白水平表达变化;采用质粒转染法在293T细胞中过表达p53后检测TOP2α蛋白水平的变化,明确p53对TOP2α表达的影响;采用BrdU标记法计算并检测干扰或过表达TOP2α表达后对前列腺癌细胞增殖能力的影响,明确TOP2α对前列腺癌细胞增殖的调节能力。结果干扰p53表达后细胞内TOP2αmRNA的表达明显升高,说明p53可以调节TOP2α的转录水平,进一步检测干扰p53表达后,TOP2α的蛋白水平表达明显升高;在细胞内,过表达p53后检测TOP2α的蛋白表达水平明显下降;在C4-2细胞中干扰目标基因TOP2α的表达后,增殖细胞的百分比从(21.54±1.443)%下降至(13.78±0.4736)%(P<0.05)。同时,在C4-2细胞中过表达TOP2α后,增殖细胞的百分比从(20.84±2.082%)上升至(33.36±3.244)%(P<0.05)。结论在前列腺癌细胞中,p53可以在mRNA和蛋白水平调节TOP2α的表达,TOP2α具有调节前列腺癌细胞增殖的能力。

Objective To investigate whether Topoisomerase（DNA）II alpha（TOP2α）promote prostate cancer cells proliferation and regulated by p53.Methods After inhibiting expression of p53 by interfering RNA（RNAi）in C4-2cells using Lipofectamine2000,the mRNA and protein expression level were assessed by Real-time PCR and Western Blot.After transfecting GFP-p53 in 293Tcells by according to the manufacturer’s instruction,the expression level of TOP2αwas assessed by Western Blot.After knockdown TOP2αby RNAi in C4-2cells,proliferation was tested by Bromodeoxyuridine incorporation assay（BrdU）.Then,the BrdU assay was repeated after transfecting GFP-TOP2α.Results The mRNA and protein level were significant increased after transfection of siRNA against p53.Moreover,proliferation was further decreased from（21.54±1.443）% to（13.78±0.4736）%（P〈0.05）.At the meantime,after transfectiong GFP-TOP2α,proliferation was further increased from（20.84±2.082%）to（33.36±3.244）%（P〈0.05）.Conclusion Our findings suggest that p53 regulates the mRNA and protein level of TOP2α,and TOP2αcould regulates proliferation ability of C4-2cells.