Department of Urology, Faculty of Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, 01307, Dresden, Germany.
German Society of Urology, UroFors Consortium (Natural Scientists in Urological Research), 14163, Berlin, Germany.
Biol Direct. 2024 Nov 11;19(1):111. doi: 10.1186/s13062-024-00550-6.
Dysregulated androgen receptor (AR) activity is central to various diseases, particularly prostate cancer (PCa), in which it drives tumour initiation and progression. Consequently, antagonising AR activity via anti-androgens is an indispensable treatment option for metastatic PCa. However, despite initial tumour remission, drug resistance occurs. Therefore, the AR signalling pathway has been intensively investigated. However, the role of AR protein stability in AR signalling and therapy resistance has not yet been deciphered. Therefore, this study aimed to investigate the role of AR protein changes in transactivity and assess its mechanism as a possible target in PCa.
LNCaP, C4-2, and 22Rv1 cells were treated with R1881, enzalutamide, cycloheximide, and Rocaglamide. Mass spectrometry analyses were performed on LNCaP cells to identify the pathways enriched by the treatments. Western blotting was performed to investigate AR protein levels and localisation changes. Changes in AR transactivity were determined by qPCR.
Mass spectrometry analyses were performed on LNCaP cells to decipher the molecular mechanisms underlying androgen- and antiandrogen-induced alterations in the AR protein. Pathway analysis revealed the enrichment of proteins involved in different pathways that regulate translation. Translational and proteasome inhibitor experiments revealed that these AR protein changes were attributable to modifications in translational activity. Interestingly, the effects on AR protein levels in castration-resistant PCa (CRPC) cells C4-2 or enzalutamide-resistant cells 22Rv1 were less prominent and non-existent. This outcome was similarly observed in the alteration of AR transactivation, which was suppressed in hormone-sensitive prostate cancer (HSPC) LNCaP cells by translational inhibition, akin to the effect of enzalutamide. In contrast, treatment-resistant cell lines showed only a slight change in AR transcription.
This study suggests that in HSPC, AR activation triggers a signalling cascade that increases AR protein levels by enhancing its translation rate, thereby amplifying AR activity. However, this mechanism appears to be dysregulated in castration-resistant PCa cells.
雄激素受体（AR）活性失调是多种疾病的核心，尤其是前列腺癌（PCa），它驱动肿瘤的起始和进展。因此，通过抗雄激素拮抗 AR 活性是转移性 PCa 不可或缺的治疗选择。然而，尽管最初肿瘤得到缓解，但仍会发生耐药性。因此，AR 信号通路已被深入研究。然而，AR 蛋白稳定性在 AR 信号和耐药性中的作用尚未被破解。因此，本研究旨在研究 AR 蛋白变化在转录活性中的作用，并评估其作为 PCa 中可能的靶点的机制。
用 R1881、恩扎卢胺、环己酰亚胺和罗卡酰胺处理 LNCaP、C4-2 和 22Rv1 细胞。对 LNCaP 细胞进行质谱分析，以确定治疗方法富集的途径。通过 Western blot 分析研究 AR 蛋白水平和定位变化。通过 qPCR 研究 AR 转录活性的变化。
对 LNCaP 细胞进行质谱分析，以破解雄激素和抗雄激素诱导的 AR 蛋白变化的分子机制。途径分析显示，参与调节翻译的不同途径的蛋白质富集。翻译和蛋白酶体抑制剂实验表明，这些 AR 蛋白变化归因于翻译活性的改变。有趣的是，在去势抵抗性 PCa（CRPC）细胞 C4-2 或恩扎卢胺耐药细胞 22Rv1 中，AR 蛋白水平的变化不明显或不存在。在激素敏感性前列腺癌（HSPC）LNCaP 细胞中，类似地观察到 AR 转录激活的改变，通过翻译抑制抑制 AR 活性，类似于恩扎卢胺的作用。相比之下，耐药细胞系中 AR 转录仅略有变化。
本研究表明，在 HSPC 中，AR 激活触发信号级联反应，通过提高其翻译率增加 AR 蛋白水平，从而放大 AR 活性。然而，这种机制似乎在去势抵抗性 PCa 细胞中失调。
