MP51-17 SPINK1 IS ASSOCIATED WITH CASTRATION RESISTANCE IN PROSTATE CANCER

Abstract

You have accessJournal of UrologyProstate Cancer: Basic Research & Pathophysiology II (MP51)1 Apr 2020MP51-17 SPINK1 IS ASSOCIATED WITH CASTRATION RESISTANCE IN PROSTATE CANCER Ikenna Madueke, Wen-Yang Hu, Lishi Xie, Donald Vander Griend, Michael Abern, Gail Prins, and Ikenna Madueke* Ikenna MaduekeIkenna Madueke More articles by this author , Wen-Yang HuWen-Yang Hu More articles by this author , Lishi XieLishi Xie More articles by this author , Donald Vander GriendDonald Vander Griend More articles by this author , Michael AbernMichael Abern More articles by this author , Gail PrinsGail Prins More articles by this author , and Ikenna Madueke*Ikenna Madueke* More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000913.017AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: SPINK1 is a secreted serine protease inhibitor that has been implicated in prostate cancer although its contribution has been controversial. Previous RNA-seq data from our lab revealed SPINK1 to be one of the most differentially expressed genes enriched in PCa stem cells compared to non-diseased progenitor population. We thus sought to investigate its role in disease progression in a prostate cancer stem cell-like cell line. METHODS: We analyzed the STand Up to Cancer database of human RNA-seq data sets for differential expression of SPINK1 in metastatic and localized PCa. We utilized ShRNA to create stable knockdown of SPINK1 in HusLC cells, a PCa stem-like cell line. MTT assay was utilized to study its effects on proliferation. Migration was assessed with scratch assay. Stemness was assayed with prostasphere formation and RT-PCR. We then assessed xenograft formation and propagation in the presence or absence of testosterone. RESULTS: RNA-seq data set of annotated human PCa metastasis revealed an increase in SPINK1 mRNA expression compared with localized tumors. SPINK1 mRNA levels are increased in HuSLC prostaspheres compared to HuSLC cells cultured in monolayer supporting a role in maintenance of a progenitor population. Knockdown of SPINK1 (SPINK1-KD) however did not change the sphere-forming capacity by size or number but did decrease stemness genes Nanog, SOX2, and Oct4 suggesting a role in affecting stemness. Knockdown of SPINK1 decreased migration and proliferation of HuSLC in monolayer indicating a decrease in SPINK1 is associated with a less aggressive phenotype. Subcutaneous xenografts developed in non-castrate nude mice and with supplemental exogenous testosterone did not reveal a difference in tumor weight or with serial transplantation. SPINK1-KD xenografts however were more secretory as assessed by PSA suggesting an increased responsiveness to testosterone. Strikingly, when the knock-down and control xenografts were cultured in castrate conditions, SPINK1-KD xenografts were drastically smaller than control HuSLC suggesting that SPINK1 is associated with promotion of castration resistance. CONCLUSIONS: The clinical significance of SPINK1 in PCa remains controversial. However, taken together, our results present supporting evidence to suggest a role for SPINK1 in promoting castration resistance in the progression of PCa disease with implications for targeted treatment. Source of Funding: None © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e770-e770 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ikenna Madueke More articles by this author Wen-Yang Hu More articles by this author Lishi Xie More articles by this author Donald Vander Griend More articles by this author Michael Abern More articles by this author Gail Prins More articles by this author Ikenna Madueke* More articles by this author Expand All Advertisement PDF downloadLoading ...