Tan Guobin, Qiu Mingning, Chen Lieqian, Zhang Sai, Ke Longzhi, Liu Jianjun
Laboratory of Urology, Guangdong Medical College, Zhanjiang, Guangdong, 524001, China.
BMC Cancer. 2017 May 26;17(1):376. doi: 10.1186/s12885-017-3351-0.
In view of the fact that JS-K might regulate ubiquitin E3 ligase and that ubiquitin E3 ligase plays an important role in the mechanism of CRPC formation, the goal was to investigate the probable mechanism by which JS-K regulates prostate cancer cells.
Proliferation inhibition by JS-K on prostate cancer cells was examined usingCCK-8 assays. Caspase 3/7 activity assays and flow cytometry were performed to examine whether JS-K induced apoptosis in prostate cancer cells. Western blotting and co-immunoprecipitation analyses investigated JS-K's effects on the associated apoptosis mechanism. Real time-PCR and Western blotting were performed to assess JS-K's effect on transcription of specific AR target genes. Western blotting was also performed to detect Siah2 and AR protein concentrations and co-immunoprecipitation to detect interactions of Siah2 and AR, NCoR1 and AR, and p300 and AR.
JS-K inhibited proliferation and induced apoptosis in prostate cancer cells. JS-K increased p53 and Mdm2 concentrations and regulated the caspase cascade reaction-associated protein concentrations. JS-K inhibited transcription of AR target genes and down-regulated PSA protein concentrations. JS-K inhibited Siah2 interactions and also inhibited the ubiquitination of AR. With further investigation, JS-K was found to stabilize AR and NCoR1 interactions and diminish AR and p300 interactions.
The present results suggested that JS-K might have been able to inhibit proliferation and induce apoptosis via regulation of the ubiquitin-proteasome degradation pathway, which represented a promising platform for the development of new compounds for PCa treatments.
鉴于JS-K可能调节泛素E3连接酶，且泛素E3连接酶在去势抵抗性前列腺癌（CRPC）形成机制中起重要作用，本研究旨在探讨JS-K调节前列腺癌细胞的可能机制。
采用CCK-8法检测JS-K对前列腺癌细胞的增殖抑制作用。通过Caspase 3/7活性检测和流式细胞术检测JS-K是否诱导前列腺癌细胞凋亡。采用蛋白质免疫印迹法和免疫共沉淀分析法研究JS-K对相关凋亡机制的影响。通过实时定量PCR和蛋白质免疫印迹法评估JS-K对特定雄激素受体（AR）靶基因转录的影响。同时采用蛋白质免疫印迹法检测Siah2和AR蛋白浓度，免疫共沉淀法检测Siah2与AR、NCoR1与AR以及p300与AR之间的相互作用。
JS-K抑制前列腺癌细胞增殖并诱导其凋亡。JS-K增加p53和Mdm2浓度，并调节与半胱天冬酶级联反应相关的蛋白浓度。JS-K抑制AR靶基因的转录并下调前列腺特异性抗原（PSA）蛋白浓度。JS-K抑制Siah2的相互作用，同时抑制AR的泛素化。进一步研究发现，JS-K稳定AR与NCoR1的相互作用，并减少AR与p300的相互作用。
本研究结果表明，JS-K可能通过调节泛素-蛋白酶体降解途径抑制前列腺癌细胞增殖并诱导其凋亡，这为开发用于前列腺癌治疗的新化合物提供了一个有前景的平台。
