前列腺癌PC3细胞中恢复Nkx3.1表达提高17β-雌二醇抗肿瘤作用

Enhancing 17β-estradiol's anti-tumor capacity by restoring the expression of Nkx3.1 in PC3 prostate cancer cells

目的调查恢复同源转录因子Nkx3.1在前列腺癌PC3细胞中表达可否提高17β-雌二醇抗肿瘤作用。方法构建Nkx3.1真核表达质粒pc DNA3.1-Nkx3.1-His,转染PC3细胞获得稳定表达Nkx3.1细胞系。MTT分析Nkx3.1对PC3细胞增殖影响。进一步通过MTT分析细胞增殖、流式细胞仪分析细胞凋亡来验证恢复PC3细胞Nkx3.1是否可提高17β-雌二醇抗肿瘤作用。此外,Western blot分析在PC3细胞中单独使用17β-雌二醇或结合Nkx3.1对凋亡相关蛋白表达影响。结果 Nkx3.1真核表达质粒在PC3细胞中获得高表达。外源性Nkx3.1表达对PC3细胞增殖无明显影响,但可明显提高17β-雌二醇抗增殖作用及诱导细胞凋亡。进一步分析凋亡相关蛋白表达显示,结合Nkx3.1与17β-雌二醇可使bcl-2表达下降、bax表达升高、caspase-3激活、PARP劈裂片段增加。结论恢复PC3细胞Nkx3.1表达可明显提高17β-雌二醇抗肿瘤作用,提示在雌激素治疗激素抵抗前列腺癌中恢复Nkx3.1表达是一值得尝试方法。

Objective To test the hypothesis that the anti-tumor capacity of 17β-estradiol can be enhanced by restoring the expression of the homeodomain transcription factor Nkx3.1 in PC3 human prostate cancer cells. Methods PC3 cells were stably transfected with pcDNA3.1-Nkx3.1-His vector which carries a full-length eDNA of human Nkx3.1. The PC3 cells stably transfected with vector pcDNA3, lwere set as control. The expression of Nkx3.1 protein in the ceils was confirmed by western blot analysis. The effect of Nkx3.1 on cell proliferation of PC3 cells were examined with MTT assay. Then the anti- proliferative and apoptotic effects of 17β-estradiol alone or combined with Nkx3. 1 were estimated on PC3 cells by MTT growth tests and flow cytometric analyses. Lastly, the expression of apoptosis-related proteins were analyzed by western blotting. Findings The plasmid carrying Nkx3. 1 gene induced high expression of Nkx3. 1 protein in PC3 cells. The re- expression of exogenous Nkx3.1 did not display significant reduction in cellular proliferation, whereas expression of Nkx3. 1 enhanced 17β-estradiol＇s anti-proliferative effect in PC3 cells. Nkx3. 1 expression promoted 17[3-estradiol-induced apoptosis of PC3 cells, as shown by analysis of Bcl-2, Bax, Caspase-3 and poly （ADP-ribose） polymerase expression. Conclusion The study demonstrated that re-expression of Nkx3. I enhances 17^-estradiol＇s anti-tumor capacity in PC3 human prostate cancer cells. The study suggested that re-expression of Nkx3. 1 is worthy of further consideration as an adjuvant way in treating androgen independent prostate cancer （AIPC） with estrogen anti-tumor theraoies.