Institute of Biochemistry and Molecular Biology, School of Medicine, Shandong University, Ji-nan, China.
Acta Pharmacol Sin. 2011 Mar;32(3):338-44. doi: 10.1038/aps.2010.219.
To examine whether two naturally occurring sesquiterpenoids (ST1 and ST2) with anti-proliferative activity in prostate cancer cells inhibit androgen receptor (AR) signaling.
Human prostate cancer cell lines LNCaP and PC3 were used. The expression of AR, AR translocation into the nucleus, and expression levels of AR coactivators ARA70 and steroid receptor coactivator-1 (SRC-1) in LNCaP cells were examined using real-time PCR and Western blot. Changes in prostate-specific antigen (PSA) protein levels, PSA promoter activity, and androgen response element (ARE)-mediated reporter gene activity were examined using enzyme-linked immunoabsorbent assay (ELISA) and transient transfection assays. Co-immunoprecipitation was performed to analyze the interaction between AR and the AR coactivators in ST1- and ST2-treated cells.
In LNCaP cells, ST1 and ST2 (40 μmol/L) led to a significant decrease in the expression of AR as well as a reduction of AR translocation into the nucleus, but had no effect on AR protein translation. ST1 and ST2 treatment also resulted in a significant decrease in the level of PSA protein secreted into the medium and was able to suppress PSA promoter-dependent and ARE-dependent luciferase activity. Furthermore, decreased expression of ARA70 and SRC-1 was observed when LNCaP cells were exposed to ST1 and ST2, which interfered with their ability to interact with AR.
The observations suggest that suppression of AR transactivation by ST1 and ST2 may be mediated, in part, by inhibiting AR nuclear translocation and/or interfering with the interaction between AR and its coactivators ARA70 and SRC-1. Therefore, sesquiterpenoids could be developed as novel therapeutic agents for treating prostate cancer.
研究两种具有抗前列腺癌细胞增殖活性的天然倍半萜（ST1 和 ST2）是否抑制雄激素受体（AR）信号。
使用人前列腺癌细胞系 LNCaP 和 PC3。使用实时 PCR 和 Western blot 检测 LNCaP 细胞中 AR 的表达、AR 向核内易位以及 AR 共激活子 ARA70 和类固醇受体共激活子-1（SRC-1）的表达水平。使用酶联免疫吸附试验（ELISA）和瞬时转染测定法检测前列腺特异性抗原（PSA）蛋白水平、PSA 启动子活性和雄激素反应元件（ARE）介导的报告基因活性。进行共免疫沉淀以分析 ST1 和 ST2 处理细胞中 AR 与 AR 共激活子之间的相互作用。
在 LNCaP 细胞中，ST1 和 ST2（40 μmol/L）导致 AR 的表达显著下降，并且 AR 向核内易位减少，但对 AR 蛋白翻译没有影响。ST1 和 ST2 处理还导致分泌到培养基中的 PSA 蛋白水平显著下降，并能够抑制 PSA 启动子依赖性和 ARE 依赖性荧光素酶活性。此外，当 LNCaP 细胞暴露于 ST1 和 ST2 时，观察到 ARA70 和 SRC-1 的表达水平降低，这干扰了它们与 AR 相互作用的能力。
这些观察结果表明，ST1 和 ST2 抑制 AR 反式激活可能部分是通过抑制 AR 核易位和/或干扰 AR 与其共激活子 ARA70 和 SRC-1 的相互作用来介导的。因此，倍半萜类化合物可开发为治疗前列腺癌的新型治疗剂。
