CYP1B1 催化的 4-OHE2 通过雌激素受体 α 介导的 IL6 激活促进前列腺癌干细胞的去势抵抗。
CYP1B1-catalyzed 4-OHE2 promotes the castration resistance of prostate cancer stem cells by estrogen receptor α-mediated IL6 activation.
机构信息
Department of Biochemistry and Molecular Biology, College of Life Sciences, Bioactive Materials Key Lab of the Ministry of Education, Nankai University, Tianjin, 300071, China.
Tianjin Key Lab of Human Development and Reproductive Regulation, Tianjin Central Hospital of Obstetrics and Gynecology, Nankai University, Tianjin, 300071, China.
出版信息
Cell Commun Signal. 2022 Mar 15;20(1):31. doi: 10.1186/s12964-021-00807-x.
BACKGROUND
Resistance to androgen deprivation therapy remains a major challenge for the clinical treatment of patients with castration-resistant prostate cancer (CRPC). CYP1B1, a critical enzyme that catalyzes the conversion of estradiol to 4-Hydroxy-17β-estradiol (4-OHE2), has been reported to promote the development and progression of hormone-related cancer, but its role in CRPC is unclear.
METHODS
To explore the underlying mechanism which CYP1B1 promotes the prostate cancer stem cells (PCSCs) characteristics, bioinformatics analyses of human clinical prostate cancer (PCa) datasets were performed. CYP1B1, IL6, and estrogen receptor-α (ERα) expression levels were evaluated in PCa and CRPC tissues via immunohistochemistry. The high-performance liquid chromatography-mass spectrometry assay was carried out to examine intracellular 4-OHE2 levels. Serum-free suspension culture and flow cytometry assays were performed to evaluate PCSCs. Chromatin immunoprecipitation was used to validate that 4-OHE2 recruited ERα to the IL6 promoter.
RESULTS
CYP1B1 expression was significantly increased in CRPC tissues and androgen-independent PCa cell lines. CYP1B1 PCa cells were significantly enriched in bicalutamide-treated LNCaP cells, and CYP1B1 knockdown reduced the cell viability under bicalutamide treatment. In addition, CYP1B1 knockdown decreased the intracellular 4-OHE2 concentration, accompanied by reduced PCSC characteristics. In PCa cells, 4-OHE2 stimulated ERα transcriptional activity and upregulated the expression of IL6 and downstream genes of the IL6-STAT3 signaling. 4-OHE2 increased cell viability under bicalutamide treatment and promoted PCSC characteristics, while IL6 neutralizing antibody reversed these effects. Mechanistically, siERα and the ER antagonist ICI182780 significantly attenuated 4-OHE2-induced IL6 expression, and 4-OHE2 promoted the binding of ERα to the estrogen response element of the IL6 promoter.
CONCLUSIONS
Our findings indicate that CYP1B1-catalyzed 4-OHE2 enhanced PCSC characteristics and attenuated bicalutamide sensitivity by ERα-mediated the IL6-STAT3 pathway activation. Our study further emphasizes the role of CYP1B1 in castration resistance and illustrates a novel mechanism of CRPC development. Video Abstract.
背景
雄激素剥夺疗法的耐药性仍然是去势抵抗性前列腺癌（CRPC）患者临床治疗的主要挑战。CYP1B1 是一种关键的酶，可催化雌二醇转化为 4-羟基-17β-雌二醇（4-OHE2），据报道，它可促进激素相关癌症的发展和进展，但在 CRPC 中的作用尚不清楚。
方法
为了探讨 CYP1B1 促进前列腺癌干细胞（PCSCs）特征的潜在机制，对人类临床前列腺癌（PCa）数据集进行了生物信息学分析。通过免疫组织化学法评估 PCa 和 CRPC 组织中 CYP1B1、IL6 和雌激素受体-α（ERα）的表达水平。采用高效液相色谱-质谱法检测细胞内 4-OHE2 水平。进行无血清悬浮培养和流式细胞术检测以评估 PCSCs。采用染色质免疫沉淀法验证 4-OHE2 将 ERα 募集到 IL6 启动子上。
结果
CYP1B1 在 CRPC 组织和雄激素非依赖性 PCa 细胞系中表达显著增加。CYP1B1 在接受比卡鲁胺治疗的 LNCaP 细胞中显著富集，并且 CYP1B1 敲低降低了比卡鲁胺治疗下的细胞活力。此外，CYP1B1 敲低降低了细胞内 4-OHE2 浓度，同时降低了 PCSC 特征。在 PCa 细胞中，4-OHE2 刺激 ERα 转录活性并上调 IL6 和 IL6-STAT3 信号转导下游基因的表达。4-OHE2 在比卡鲁胺治疗下增加细胞活力并促进 PCSC 特征，而 IL6 中和抗体逆转了这些作用。在机制上，siERα 和 ER 拮抗剂 ICI182780 显著减弱了 4-OHE2 诱导的 IL6 表达，并且 4-OHE2 促进了 ERα 与 IL6 启动子上的雌激素反应元件的结合。
结论
我们的研究结果表明，CYP1B1 催化的 4-OHE2 通过 ERα 介导的 IL6-STAT3 通路激活增强了 PCSC 特征并减弱了比卡鲁胺的敏感性。我们的研究进一步强调了 CYP1B1 在去势抵抗中的作用，并阐明了 CRPC 发展的新机制。
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