The NF-KappaB-Androgen Receptor Axis Drives Failure of Medical Therapy in Human Benign Prostatic Hyperplasia

项目总结 除了年龄增长和雄激素活性失调外，人们对前列腺增生症的发病机制知之甚少。 以及为什么患者对现有药物的反应非常不同。类固醇5α还原酶抑制剂(5ARI)阻断 将睾酮(T)转化为双氢睾酮(DHT)，是治疗缩水的主要疗法 约34%有症状的BPH患者的前列腺体积。我们的数据表明了一个基本的 褐飞虱对5ARIs的抗性机制。我们发现核因子-kappaB(NF-κ-B)在 雄激素受体变异体7(AR-V7)的诱导，这是一种缺乏配体结合结构域(LBD)的AR亚型 全长AR(AR-FL)，导致即使在没有DHT的情况下也能产生结构性活跃的AR信号。我们 首次证明有严重症状的良性前列腺增生症患者表达AR-Vs，并且NFκB调节 AR-FL和AR-V7在自然永生化的人前列腺细胞中的表达 此外，在良性前列腺细胞中表达NFκB或AR-V7足以诱导对5ARI的抵抗 治疗。此外，我们还发现，核因子κB和AR-V7上调类固醇-5α还原酶II(SRD5A2)。 表情。与我们的细胞培养实验一致，我们显示BPH患者的样本 核因子κB、AR-V7和SRD5A2的表达水平。我们证明AR-V7和SRD5A2的表达 与经直肠超声(TRUS)、前列腺体积和美国泌尿外科显著相关 前列腺增生症患者的相关症状评分(AUASS)及患者下尿液严重程度的测量 肠道症状(LUTS)。这一数据表明了一种良性前列腺增生症模型，在该模型中形成了一个自力更生的循环来克服 由核因子κB和AR-V7触发的药物治疗，以提高SRD5A2水平和二羟色胺的产生，以恢复 启动AR-FL活动。我们的假设是，NFκB和AR信号控制着对5ARI的失败反应 前列腺增生症。为了揭示5ARI的失效机制，我们提出了三个具体的目标：1)确定串扰 在核转录因子κB和AR信号之间调节药物治疗失败；2)确定SRD5A亚型 以及3)确定药物治疗失败是否由 良性前列腺增生症患者血清中NF-κB和/或AR-V7的表达这些目标将使用分子方法，雄激素的测量 和5ARI水平和基因在BPH组织中的表达，并从BPH患者的3D器官培养中检测 5ARI治疗失败的机制。我们的模型可以提供一种通用的机制来解释 药物治疗，或者它可能识别BPH患者的一个亚群，这可能为精确度指明方向 为这些患者提供个性化护理的药物。

PROJECT SUMMARY With the exception of increasing age and dysregulated androgen activity, little is known on how BPH develops and why patients respond very differently to existing drugs. Steroid 5α-reductase inhibitors (5ARI) block the conversion of testosterone (T) to dihydrotestosterone (DHT), representing a major therapy for shrinking prostate volume in approximately 34% of symptomatic BPH patients. Our data suggest a fundamental mechanism underlying the resistance of BPH to 5ARIs. We show that nuclear factor kappa B (NFκB) mediates induction of Androgen Receptor Variant 7 (AR-V7), an AR isoform that lacks the Ligand Binding Domain (LBD) of the full-length AR (AR-FL), resulting in constitutively active AR signaling even in the absence of DHT. We demonstrate for the first time that severely symptomatic BPH patients express AR-Vs, and that NFκB regulates the expression of AR-FL and AR-V7 mRNA in spontaneously immortalized human benign prostatic cells. Further, expression of NFκB or AR-V7 in benign prostatic cells is sufficient to induce resistance to 5ARI treatment. Also, we show that NFκB and AR-V7 up-regulate steroid-5α-reductase type II (SRD5A2) expression. Consistent with our cell culture experiments, we show that BPH patient samples have elevated levels of NFκB, AR-V7, and SRD5A2 expression. We demonstrate that AR-V7 and SRD5A2 expression significantly correlated with the Transrectal ultrasound (TRUS) prostatic volume and American Urological Association Symptom Scores (AUASS) in BPH patients, measures of the patients' severity of lower urinary tract symptoms (LUTS). This data suggests a BPH model where a loop of self-reliance develops to overcome medical therapy that is triggered by NFκB and AR-V7 to raise SRD5A2 levels and the production of DHT to re- initiate AR-FL activity. Our Hypothesis is that NFκB and AR signaling controls the failed response to 5ARIs in BPH. To unravel the mechanism of failure of 5ARI, we propose three Specific Aims: 1) To determine cross-talk between NFκB and AR signaling to regulate failure of medical therapy; 2) To determine the SRD5A isoforms contribution during resistance to medical therapy; and 3) To determine if failure of medical therapy is driven by NFκB and/or AR-V7 in BPH patients. These aims will use molecular approaches, measurements of androgens and 5ARI levels and gene expression in BPH tissue, and 3D organoid cultures from BPH patients to test the mechanism of failure to 5ARI therapy. Our model may provide a general mechanism explaining failure of medical therapy or it may identify a subpopulation of BPH patients which could point the way towards precision medicine that would personalize care for these patients.