Nuclear-specific AR-V7 Protein Localization is Necessary to Guide Treatment Selection in Metastatic Castration-resistant Prostate Cancer

Background

Circulating tumor cells (CTCs) expressing AR-V7 protein localized to the nucleus (nuclear-specific) identify metastatic castration-resistant prostate cancer (mCRPC) patients with improved overall survival (OS) on taxane therapy relative to the androgen receptor signaling inhibitors (ARSi) abiraterone acetate, enzalutamide, and apalutamide.

Expression of AR-V7 in Circulating Tumour Cells Does Not Preclude Response to Next Generation Androgen Deprivation Therapy in Patients with Castration Resistant Prostate Cancer

The androgen receptor splice variant AR-V7 has recently been discussed as a predictive biomarker for nonresponse to next-generation androgen deprivation therapy (ADT) in patients with castration-resistant prostate cancer. However, we recently identified one patient showing a response from abiraterone despite expression of AR-V7 in his circulating tumour cells (CTC).Therefore, we precisely assessed the response in a cohort of 21 AR-V7 positive castration-resistant prostate cancer patients who had received therapy with abiraterone or enzalutamide. We detected a subgroup of six AR-V7 positive patients showing benefit from either abiraterone or enzalutamide. Their progression free survival was 26 d (censored) to 188 d. Four patients displayed a prostate-specific antigen decrease of >50%. When analysing prior therapies, we noticed that only one of the six patients had received next-generation ADT prior to CTC collection.As a result, we conclude that AR-V7 status in CTC cannot entirely predict nonresponse to next generation ADT and AR-V7-positive patients should not be systematically denied abiraterone or enzalutamide treatment, especially as effective alternative treatment options are still limited.

AR-V7表达与去势抵抗性前列腺癌阿比特龙治疗敏感性的相关性研究

目的:探讨去势抵抗性前列腺癌(CRPC)患者中雄激素受体剪切变异体7(AR-V7)的表达与阿比特龙治疗敏感性的相关性。方法:采用前瞻性队列研究对2016年1月至2019年1月北京大学肿瘤医院收治的年龄≥18岁,存在1≥处全身转移,拟使用阿比特龙治疗的新发CRPC患者行外周血循环肿瘤细胞(CTCs)AR-V7检测,根据检测结果将患者分为AR-V7阳性组和AR-V7阴性组,对两组患者PSA下降时间、PSA无进展生存(PFS)、临床状态PFS、影像学PFS以及总生存进行统计分析。结果:共入组77例患者,其中AR-V7阴性组49例,AR-V7阳性组28例。AR-V7阴性组PSA下降时间[(72.04±66.92)d与(190.11±102.44)d,P=0.000]、PSA无应答率[6.12%(3/49)与21.4%(6/28),P=0.040]明显小于AR-V7阳性组,而PSA PFS[(489.17±269.39)d与(130.56±120)d,P=0.010]、临床状态PFS[(551.91±322.05)d与(261.44±200.85)d,P=0.018]、影像学PFS[(523.7±223.28)d与(247.56±202.80)d,P=0.003]明显长于AR-V7阳性组。AR-V7阳性组和AR-V7阴性组的肿瘤特异性生存时间分别为(1246.89±375.65)d和(1001.42±248.94)d(P=0.159),总生存率分别为89.8%(44/49)和89.3%(25/28)(P=0.176),差异均无统计学意义。结论:CRPC患者中,AR-V7表达与阿比特龙治疗敏感性及患者预后密切相关,阳性表达患者阿比特龙治疗效果及预后较差。     

Clinical Utility of the Nuclear-localized AR-V7 Biomarker in Circulating Tumor Cells in Improving Physician Treatment Choice in Castration-resistant Prostate Cancer

BackgroundProof of the clinical utility of a biomarker is when its use informs a management decision and improves patient outcomes relative to when it is not used.ObjectiveTo model the clinical benefit of the nuclear-localized androgen receptor splice variant 7 (AR-V7) test for men with progressing metastatic castration-resistant prostate cancer (mCRPC) at the second line of therapy or greater to inform the choice of an androgen receptor signaling inhibitor (ARSI) or a taxane.Design, setting, and participantsThe study population was a cross-sectional cohort of 193 unique patients with progressing mCRPC from whom 255 samples were drawn at the time of the second line or later treatment decision who then received an ARSI or taxane, with up to 3 yr of additional follow-up Circulating tumor cells (CTCs) were identified from blood samples and tested for AR-V7. Physicians were blinded to AR-V7 status and the testing laboratory was blinded to outcomes.Outcome measurements and statistical analysesWe measured physician propensity for choosing an ARSI or taxane based on patient prognosis. We also measured overall survival (OS) adjusted for physician propensity by drug class; OS data were analyzed both without and with knowledge of nuclear-localized AR-V7 status.Results and limitationsTreating physicians had a propensity for choosing a taxane over an ARSI for patients with more advanced disease or who received an ARSI as the immediate prior therapy. After adjusting for physician propensity, discernible OS differences were not observed between taxane- and ARSI-treated patients (median 15.6 vs 14.4 mo; p =0.11). Patients with detectable nuclear-localized AR-V7 in CTCs had superior survival with taxanes over ARSIs (median 9.8 vs 5.7 mo; p = 0.041). AR-V7–negative patients had superior survival on ARSIs over taxanes (p = 0.033) but overlapping curves limit the interpretation. Mutivariable models showed a robust interaction between AR-V7 status and drug, and a lower risk of death on taxanes for AR-V7–positive men.ConclusionsUse of the nuclear-localized AR-V7 CTC test to inform treatment choice can improve patient outcomes relative to decisions based solely on standard-of-care measures.Patient summaryMen with metastatic prostate cancer who test positive for AR-V7 protein in circulating tumor cells are likely to live longer if taxane chemotherapy is used.     

Plasma Androgen Receptor and Docetaxel for Metastatic Castration-resistant Prostate Cancer

Plasma androgen receptor (AR) gain identifies metastatic castration-resistant prostate cancer (mCRPC) patients with worse outcome on abiraterone/enzalutamide, but its relevance in the context of taxane chemotherapy is unknown. We aimed to evaluate whether docetaxel is active regardless of plasma AR and to perform an exploratory analysis to compare docetaxel with abiraterone/enzalutamide. This multi-institutional study was a pooled analysis of AR status, determined by droplet digital polymerase chain reaction, on pretreatment plasma samples. We evaluated associations between plasma AR and overall/progression-free survival (OS/PFS) and prostate-specific antigen (PSA) response rate in 163 docetaxel-treated patients. OS was significantly shorter in case of AR gain (hazard ratio [HR] = 1.61, 95% confidence interval [CI] = 1.08–2.39, p = 0.018), but not PFS (HR = 1.04, 95% CI 0.74–1.46, p = 0.8) or PSA response (odds ratio = 1.14, 95% CI = 0.65–1.99, p = 0.7). We investigated the interaction between plasma AR and treatment type after incorporating updated data from our prior study of 73 chemotherapy-naïve, abiraterone/enzalutamide-treated patients, with data from 115 first-line docetaxel patients. In an exploratory analysis of mCRPC patients receiving first-line therapies, a significant interaction was observed between plasma AR and docetaxel versus abiraterone/enzalutamide for OS (HR = 0.16, 95% CI = 0.06–0.46, p < 0.001) and PFS (HR = 0.31, 95% CI = 0.12–0.80, p = 0.02). Specifically, we reported a significant difference for OS favoring abiraterone/enzalutamide for AR-normal patients (HR = 1.93, 95% CI = 1.19–3.12, p = 0.008) and a suggestion favoring docetaxel for AR-gained patients (HR = 0.53, 95% CI = 0.24–1.16, p = 0.11). These data suggest that AR-normal patients should receive abiraterone/enzalutamide and AR-gained could benefit from docetaxel. This treatment selection merits prospective evaluation in a randomized trial.

Overexpression of nuclear AR-V7 protein in primary prostate cancer is an independent negative prognostic marker in men with high-risk disease receiving adjuvant therapy

Background

Overexpression of the androgen receptor (AR) splice variant 7 (AR-V7) has recently been reported to be associated with resistance to antihormonal therapy. Herein, we address the question whether tumor cells with AR-V7 expression can be detected at the time of radical prostatectomy, that is, before long-term hormonal manipulation and castration resistance, and what the potential prognostic impact on the biochemical recurrence (BCR)-free survival may be.

Role of Androgen Receptor Variants in Prostate Cancer: Report from the 2017 Mission Androgen Receptor Variants Meeting

Context

Although a number of studies have demonstrated the importance of constitutively active androgen receptor variants (AR-Vs) in prostate cancer, questions still remain about the precise role of AR-Vs in the progression of castration-resistant prostate cancer (CRPC).

A Multicohort Open-label Phase II Trial of Bipolar Androgen Therapy in Men with Metastatic Castration-resistant Prostate Cancer (RESTORE): A Comparison of Post-abiraterone Versus Post-enzalutamide Cohorts

BackgroundCyclic high-dose testosterone injections, also known as bipolar androgen therapy (BAT), is a novel treatment strategy for patients with metastatic castration-resistant prostate cancer (mCRPC). BAT has shown clinical activity in prior studies enrolling men with mCRPC and may potentially restore sensitivity to prior androgen receptor (AR)-targeted agents.ObjectiveTo evaluate the clinical activity of BAT in patients progressing on AR-targeted therapy as well as responses to abiraterone or enzalutamide upon rechallenge after BAT.Design, setting, and participantsRESTORE is a multicohort phase II study enrolling asymptomatic mCRPC patients after abiraterone or enzalutamide at Johns Hopkins Hospital (NCT02090114). Participants (29 after abiraterone and 30 after enzalutamide) received 400 mg testosterone cypionate intramuscularly every 28 days, with ongoing luteinizing hormone-releasing hormone agonist/antagonist treatment (ie, BAT). Following progression on BAT, patients were rechallenged with their most recent AR-targeted therapy.Outcome measurements and statistical analysisCoprimary endpoints were >50% decline in PSA from baseline (PSA₅₀) responses to BAT and following AR-targeted therapy rechallenge. Outcomes in the post-abiraterone cohort are presented, as well as updated results from the post-enzalutamide cohort and an exploratory AR-V7 analysis.Results and limitationsNo statistically significant difference in PSA₅₀ response rates to BAT was observed (30% [post-enzalutamide cohort] vs 17% [post-abiraterone cohort], p = 0.4). However, PSA₅₀ responses to AR-targeted therapy rechallenge were higher in the post-enzalutamide cohort (68% vs 16%, p = 0.001). The median time from enrollment to progression following rechallenge with AR-targeted therapy (ie, progression-free survival 2; PFS2) was longer in the post-enzalutamide versus post-abiraterone patients (12.8 vs 8.1 mo, p = 0.04). Outcomes were worse in patients with detectable AR-V7 in circulating tumor cells (median PFS2: 10.3 vs 7.1 mo, p = 0.005).ConclusionsBAT shows clinical activity in mCRPC patients and may be more effective at resensitizing to enzalutamide versus abiraterone.Patient summaryBAT is well tolerated in metastatic castration-resistant prostate cancer patients. The type of prior AR-targeted therapy might affect response to BAT as well as AR-therapy rechallenge. BAT followed by AR-targeted therapy rechallenge did not improve outcomes in AR-V7–positive patients.     

Androgen Receptor Expression in Prostatic Dysplasia (Prostatic lntraepithelial Neoplasia) in the Human Prostate: An Immunohistochemical and In Situ Hybridization Study

To evaluate the role of androgens in the pathogenesis of prostatic dysplasia, we compared the localization of androgen receptor (AR) in proliferative and nonproliferative cells in normal and dysplastic acini. Basal cells, the only proliferating cells identified in normal aani, contained AR mRNA but lacked an immunodetectable receptor. Both AR mRNA and immunodetectable receptor were present, however, in secretory and stromal cells. Androgen receptor localization in dysplastic lesions was identical to normal but here the proliferative marker Ki-67 was found in both basal and secretory cells. Our findings suggest that androgens do not directly initiate the division of basal cells, the putative precursors of secretory cells. Instead, the hormone may act through its fully translated receptor to mainly mediate the differentiation of secretory cells. The presence of both AR and Ki-67 in dysplastic secretory cells may indicate an abnormal direct androgen-mediated proliferation in this compartment. This is consistent with previous evidence that secretory cell differentiation is impaired in dysplasia. © 1996 Wiley-Liss, Inc.     

不同标准对荧光原位杂交技术在膀胱癌诊断中应用的影响

目的：探讨不同标准对荧光原位杂交技术（fluorescence in situ hybridization,FISH）诊断膀胱癌的敏感度和特异性的影响。方法：选择20例健康人为正常组,计算FISH检查正常阈值;选择143例血尿患者为病例组．经F1SH检查、尿脱落细胞学检查,比较Urovysion膀胱癌探针斌剂盒标准和正常闯值标准诊断膀胱癌的敏感度和特异性。结果：采用Urovysion标准和正常阈值标准对膀胱癌的诊断敏感度分别为73．1％和100％．均较尿脱落细胞学检查明显增高,三者对膀胱癌诊断的特异性分别为90．0％、86%和100％。Urovysion标准与尿脱落细胞学联合检查时对膀胱癌诊断的敏感度明显升高,差异具有统计学意义（P〈0．01）。结论：FISH检查较尿脱落细胞学检查诊断膀胱癌的敏感度显著提高,相比Urovysion际准,正常闯值更适合FISH诊断膀胱癌的标准。FISH与尿脱落细胞学联合检查能显著提高膀胱癌的诊断敏感度。     

荧光原位杂交技术检测膀胱肿瘤组织中染色体的表达及意义

目的：利用荧光原位杂交技术（fluorescence in situ hybridization,FISH）,分析膀胱肿瘤中染色体畸变情况,探讨膀胱尿路上皮癌和非尿路上皮癌中染色体的表达及意义。方法：采用FISH技术检测25例膀胱尿路上皮癌、13例非尿路上皮癌（7例鳞癌,6例腺癌）标本中3、7、17号染色体及9p21的表达,以15例正常膀胱组织作为阴性对照。结果：38例膀胱肿瘤标本中3、7、17号染色体扩增明显,其中染色体在肿瘤和正常组织中平均拷贝数分别为：3号染色体为2．43VS．1．46,7号染色体为2．29vs．1．44,17号染色体为2．29VS．1．30（P〈O．01）。9号染色体P16基因为1．36VS．1．14（P=0．05）。3、7、17号染色体在膀胱尿路上皮癌和非尿路上皮癌中扩增率差异无统计学意义,而9p2l缺失率在两者中明显相关,在移行细胞癌、鳞癌、腺癌缺失率为52．0％（13／25）、100％（7／7）、83．7％（5／6）（P=0．037）。结论：采用FISH技术检测有助于探索3、7、17号染色体及9p21畸变与肿瘤类型的关系,并可作为膀胱非尿路上皮癌早期诊断的有用指标。     

人和小鼠Dspp基因的克隆及其在成牙本质细胞中的表达检测

目的 克隆人和小鼠牙本质涎磷蛋白(DSPP)基因片断,建立一种从分子水平检测成牙本质细胞分化的方法.方法 制备特异性的人和小鼠Dspp基因片断的mRNA反义探针,再将其分别与人和小鼠具有成牙本质细胞的牙胚组织进行原位杂交,检测Dspp基因表达情况.结果 本实验制备出的人和小鼠Dspp基因的mRNA反义探针在特定条件下能对各自的成牙本质细胞中Dspp基因的表达进行检测.结论 本方法可以作为一种从分子水平检测人或小鼠成牙本质细胞分化的工具.     

雄激素受体mRNA在大鼠颌下腺的定位及功能

目的 :探讨大鼠颌下腺雄激素受体 (AR)mRNA的定位 ,并对其潜在的功能作进一步的研究。　方法 :采用原位杂交技术检测ARmRNA在颌下腺的定位 ,并用放射免疫分析技术测定培养细胞上清液中表皮生长因子(EGF)的含量。　结果 :ARmRNA主要分布在颌下腺的分泌管、排泄管及周围的浆液性腺泡上皮细胞内。信号物质均分布在胞质内 ,胞核阴性 ;在实验组加入一定浓度的睾酮后 ,培养细胞的上清液中EGF的浓度与对照组相比显著升高 (P <0 .0 5 )。　结论 :大鼠颌下腺有AR的存在 ,且AR是由颌下腺自身合成的。雄激素作用于培养的颌下腺细胞 ,能引起培养细胞分泌EGF能力的增加 ,说明雄激素与颌下腺上的AR结合后 ,通过特定的生理过程 ,刺激了颌下腺的分泌功能。提示AR基因可能在调节颌下腺功能方面起重要作用。