Detection of androgen receptor (AR) and AR-V7 in small cell prostate carcinoma: Diagnostic and therapeutic implications  

作　　者：Pei Zhao Yezi Zhu Liang Cheng Jun Luo 

机构地区：[1]Department of Urology,Johns Hopkins University School of Medicine,Baltimore,MD,USA [2]Department of Pathology and Laboratory Medicine,Indiana University School of Medicine,Indianapolis,IN,USA

出　　处：《Asian Journal of Urology》2019年第1期109-113,共5页亚洲泌尿外科杂志（英文）

基　　金：The work at Johns Hopkins University School of Medicine was supported by National Institutes of Health Grants(R01 CA185297 and P30 CA006973);Department of Defense Prostate Cancer Research Program Grants(W81XWH-15-2-0050);Johns Hopkins Prostate SPORE Grant(P50 CA058236);the Prostate Cancer Foundation.

摘　　要：Objective:Small cell prostate carcinoma(SCPC)is a rare and highly malignant subtype of prostate cancer.SCPC frequently lacks androgen receptor(AR)and prostate-specific antigen(PSA)expression,and often responds poorly to androgen deprivation therapy(ADT).AR splice variant-7(AR-V7)is a truncated AR protein implicated in resistance to AR-targeting therapies.AR-V7 expression in castration-resistant prostate cancers has been evaluated extensively,and blood-based detection of AR-V7 has been associated with lack of response to abiraterone and enzalutamide.However,whether AR-V7 is expressed in SCPC is not known.Methods:Using validated antibodies,we performed immunohistochemistry(IHC)assay for the full-length AR(AR-FL)and(AR-V7)on post-ADT surgical SCPC specimens.Results:Seventy-five percent(9/12)of the specimens showed positive staining for the AR-FL with various intensities.Thirty-three percent(4/12)of the specimens showed positive staining for AR-V7.Among the specimens with positive AR-V7 staining,two samples displayed very weak staining,one sample showed weak-to-moderate staining,and one sample showed strong staining.All positive specimens displayed a heterogeneous pattern of AR-FL/AR-V7 staining.All specimens positive for AR-V7 were also positive for AR-FL.Conclusion:The study findings support the existence of measurable AR-FL and AR-V7 proteins in SCPC specimens.The results also have implications in detection of AR-V7 in specimens obtained through systemic sampling approaches such as circulating tumor cells.A positive AR-V7 finding by blood-based tests is not impossible in patients with SCPC who often demonstrate low PSA values.

关 键 词：Small cell prostate carcinoma Androgen receptor Androgen receptor splice variant-7 IMMUNOHISTOCHEMISTRY 

分 类 号：R73[医药卫生—肿瘤]