Transcriptional repression and inhibition of nuclear translocation of androgen receptor by diallyl trisulfide in human prostate cancer cells.
Transcriptional repression and inhibition of nuclear translocation of androgen receptor by diallyl trisulfide in human prostate cancer cells.
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DOI：
10.1158/1078-0432.ccr-09-0512
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发表时间：
2009-08-01
期刊：
影响因子：
--
通讯作者：
Singh SV
中科院分区：
文献类型：
--
作者：
Stan SD;Singh SV
本研究是进行，以确定二烯丙基三硫化物（DATS），大蒜的一种有前途的癌症化学预防成分，雄激素受体（AR）蛋白的表达和功能，使用前列腺癌细胞的影响。免疫印迹法测定AR和前列腺特异性抗原（PSA）的蛋白水平。采用荧光素酶报告基因检测法和定量RT-PCR法检测DATS处理对AR mRNA水平和AR启动子活性的影响。采用免疫组化方法检测转基因小鼠前列腺癌（TRAMP）小鼠前列腺低分化癌和正常前列腺组织中AR蛋白的表达。共聚焦显微镜观察AR核转位情况。通过台盼蓝染料排斥试验测定细胞活力。前列腺癌细胞（LNCaP、C4-2和TRAMP-C1）暴露于DATS导致AR蛋白水平的浓度依赖性降低，同时伴有PSA细胞内和分泌水平的抑制。结构-活性研究揭示了烯丙基和寡硫化物链长度在DATS介导的AR蛋白下调中的关键作用。定量RT-PCR显示AR mRNA水平呈剂量依赖性降低，这与AR启动子活性的抑制有关。DATS处理抑制合成雄激素（R1881）刺激的LNCaP/C4-2细胞中AR的核转位和LNCaP细胞的增殖。口服灌胃2 mg DATS/d（每周3次，持续13周）显著抑制TRAMP小鼠低分化前列腺癌中的AR蛋白水平。本研究首次证明，DATS治疗抑制前列腺癌细胞中的AR功能。
The present study was undertaken to determine the effect of diallyl trisulfide (DATS), a promising cancer chemopreventive constituent of garlic, on androgen receptor (AR) protein expression and function using prostate cancer cells. Protein levels of AR and prostate specific antigen (PSA) were determined by immunoblotting. Effect of DATS treatment on AR mRNA level and AR promoter activity was determined by quantitative RT-PCR and luciferase reporter assay, respectively. Expression of AR protein in poorly-differentiated carcinoma and normal prostate of Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) mice was determined by immunohistochemistry. Confocal microscopy was performed to determine nuclear translocation of AR. Cell viability was determined by trypan blue dye exclusion assay. Exposure of prostate cancer cells (LNCaP, C4-2, and TRAMP-C1) to DATS resulted in a concentration-dependent decrease in protein level of AR, which was accompanied by suppression of intracellular and secreted levels of PSA. Structure-activity studies revealed critical roles for allyl groups and the oligosulfide chain length in DATS-mediated down-modulation of AR protein. Quantitative RT-PCR showed a dose-dependent decrease in AR mRNA level, which correlated with inhibition of AR promoter activity. DATS treatment inhibited synthetic androgen (R1881)-stimulated nuclear translocation of AR in LNCaP/C4-2 cells and proliferation of LNCaP cells. Oral gavage of 2 mg DATS/d (thrice per week for 13 weeks) markedly suppressed AR protein level in poorly-differentiated prostate cancer in TRAMP mice. The present study demonstrates, for the first time, that DATS treatment suppresses AR function in prostate cancer cells.