Sawada Takahiro, Kanemoto Yoshiaki, Amano Rei, Hayakawa Akira, Kurokawa Tomohiro, Mori Jinichi, Kato Shigeaki
Graduate School of Life Science and Engineering, Iryo Sosei University, Iino, Chuo-dai, Iwaki, Fukushima, 9708551, Japan; Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima, Japan.
Research Institute of Innovative Medicine, Tokiwa Foundation, Iwaki, Fukushima, Japan.
Biochem Biophys Res Commun. 2022 Jul 5;612:110-118. doi: 10.1016/j.bbrc.2022.04.109. Epub 2022 Apr 26.
The clinical use of androgen receptor (AR) antagonists has been successful in treating prostate cancer patients, inducing remission of androgen-dependent tumors. However, a couple of years after treatment, prostate tumors transition into an androgen-independent state with altered gene expression profiles, but the molecular basis is not understood. Since the AR antagonists trigger this transition, we assessed whether AR antagonists induce chromatin reorganization in an androgen-dependent prostate cancer cell line (LNCaP). Treatment of LNCaP cells with two clinically used AR antagonists (bicalutamide [Bic] and enzalutamide [Enz]) expectedly resulted in antagonistic effects on cell proliferation, AR transactivation, and dihydrotestosterone (DHT)-induced expression of AR target genes. Thus, the antagonists expectedly acted to antagonize the transactivation function of AR activated by androgen binding. By ChIP-qPCR assay, AR bound to Bic, but not Enz, was recruited to an endogenous consensus AR-binding site within the kallikrein-related peptidase 3 gene promoter after treatment with Bic, similar to the effect of DHT. By ATAC-seq analysis of the cells after long-term treatment for 5 days, Bic and dihydrotestosterone DHT induced different chromatin reorganization patterns and gene expression profiles, suggesting that Bic exhibited a distinct action from that by DHT. Thus, these results suggest that the action of a known AR antagonist is mediated by chromatin reorganization in a prostate cancer cell line.
雄激素受体（AR）拮抗剂的临床应用已成功用于治疗前列腺癌患者，可诱导雄激素依赖性肿瘤缓解。然而，治疗几年后，前列腺肿瘤会转变为雄激素非依赖性状态，基因表达谱发生改变，但其分子基础尚不清楚。由于AR拮抗剂会引发这种转变，我们评估了AR拮抗剂是否会在雄激素依赖性前列腺癌细胞系（LNCaP）中诱导染色质重组。用两种临床使用的AR拮抗剂（比卡鲁胺[Bic]和恩杂鲁胺[Enz]）处理LNCaP细胞，预期会对细胞增殖、AR反式激活以及二氢睾酮（DHT）诱导的AR靶基因表达产生拮抗作用。因此，这些拮抗剂预期会拮抗雄激素结合激活的AR的反式激活功能。通过染色质免疫沉淀定量PCR（ChIP-qPCR）分析，与DHT的作用类似，用Bic处理后，与Bic结合的AR（而非与Enz结合的AR）被募集到激肽释放酶相关肽酶3基因启动子内的一个内源性共有AR结合位点。通过对长期处理5天后的细胞进行转座酶可及染色质测序（ATAC-seq）分析，Bic和二氢睾酮（DHT）诱导了不同的染色质重组模式和基因表达谱，表明Bic表现出与DHT不同的作用。因此，这些结果表明，已知AR拮抗剂的作用是由前列腺癌细胞系中的染色质重组介导的。
