Parajuli Keshab R, Zhang Qiuyang, Liu Sen, Patel Neil K, Lu Hua, Zeng Shelya X, Wang Guangdi, Zhang Changde, You Zongbing
Department of Structural & Cellular Biology, Tulane University New Orleans, LA, USA.
Department of Biochemistry and Molecular Biology, Tulane University New Orleans, LA, USA ; Tulane Cancer Center and Louisiana Cancer Research Consortium, Tulane University New Orleans, LA, USA.
Am J Clin Exp Urol. 2014 Dec 25;2(4):300-12. eCollection 2014.
Methoxyacetic acid (MAA) is a primary metabolite of ester phthalates that are used in production of consumer products and pharmaceutical products. MAA causes embryo malformation and spermatocyte death through inhibition of histone deacetylases (HDACs). Little is known about MAA's effects on cancer cells. In this study, two immortalized human normal prostatic epithelial cell lines (RWPE-1 and pRNS-1-1) and four human prostate cancer cell lines (LNCaP, C4-2B, PC-3, and DU-145) were treated with MAA at different doses and for different time periods. Cell viability, apoptosis, and cell cycle analysis were performed using flow cytometry and chemical assays. Gene expression and binding to DNA were assessed using real-time PCR, Western blot, and chromatin immunoprecipitation analyses. We found that MAA dose-dependently inhibited prostate cancer cell growth through induction of apoptosis and cell cycle arrest at G1 phase. MAA-induced apoptosis was due to down-regulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2, also named cIAP1), leading to activation of caspases 7 and 3 and turning on the downstream apoptotic events. MAA-induced cell cycle arrest (mainly G1 arrest) was due to up-regulation of p21 expression at the early time and down-regulation of cyclin-dependent kinase 4 (CDK4) and CDK2 expression at the late time. MAA up-regulated p21 expression through inhibition of HDAC activities, independently of p53/p63/p73. These findings demonstrate that MAA suppresses prostate cancer cell growth by inducing growth arrest and apoptosis, which suggests that MAA could be used as a potential therapeutic drug for prostate cancer.
甲氧基乙酸（MAA）是酯邻苯二甲酸酯的主要代谢产物，酯邻苯二甲酸酯用于生产消费品和药品。MAA通过抑制组蛋白脱乙酰酶（HDACs）导致胚胎畸形和精母细胞死亡。关于MAA对癌细胞的影响知之甚少。在本研究中，用不同剂量的MAA处理两种永生化人正常前列腺上皮细胞系（RWPE-1和pRNS-1-1）和四种人前列腺癌细胞系（LNCaP、C4-2B、PC-3和DU-145），处理时间也不同。使用流式细胞术和化学分析进行细胞活力、凋亡和细胞周期分析。使用实时PCR、蛋白质印迹和染色质免疫沉淀分析评估基因表达和与DNA的结合。我们发现，MAA通过诱导凋亡和使细胞周期停滞在G1期，剂量依赖性地抑制前列腺癌细胞生长。MAA诱导的凋亡是由于抗凋亡基因杆状病毒凋亡蛋白重复序列包含蛋白2（BIRC2，也称为cIAP1）的下调，导致半胱天冬酶7和3激活并开启下游凋亡事件。MAA诱导的细胞周期停滞（主要是G1停滞）是由于早期p21表达上调以及后期细胞周期蛋白依赖性激酶4（CDK4）和CDK2表达下调。MAA通过抑制HDAC活性上调p21表达，独立于p53/p63/p73。这些发现表明，MAA通过诱导生长停滞和凋亡来抑制前列腺癌细胞生长，这表明MAA可作为前列腺癌的潜在治疗药物。
