PD32-11 GENE EXPRESSION ANALYSIS OF BONE METASTASIS AND CIRCULATING TUMOR CELLS FROM METASTATIC CASTRATE-RESISTANT PROSTATE CANCER PATIENTS

Abstract

You have accessJournal of UrologyProstate Cancer: Advanced (including Drug Therapy) III1 Apr 2016PD32-11 GENE EXPRESSION ANALYSIS OF BONE METASTASIS AND CIRCULATING TUMOR CELLS FROM METASTATIC CASTRATE-RESISTANT PROSTATE CANCER PATIENTS Won-Jin Cho, Michael Cher, Daniel Oliveira, Abdo Najy, Leandro Mainetti, Elisabeth Heath, Kim Hyeong-Reh, and R. Daniel Bonfil Won-Jin ChoWon-Jin Cho More articles by this author , Michael CherMichael Cher More articles by this author , Daniel OliveiraDaniel Oliveira More articles by this author , Abdo NajyAbdo Najy More articles by this author , Leandro MainettiLeandro Mainetti More articles by this author , Elisabeth HeathElisabeth Heath More articles by this author , Kim Hyeong-RehKim Hyeong-Reh More articles by this author , and R. Daniel BonfilR. Daniel Bonfil More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.687AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Characterization of gene expression in bone metastasis is critical to the identification of therapeutic targets and prognostic/predictive biomarkers in metastatic castrate-resistant prostate cancer (mCRPC). Although bone marrow tissue can be obtained for molecular analysis, bone marrow biopsy (BMBx) is relatively invasive. In contrast, circulating tumor cells (CTCs) can be obtained by simple blood draw, and in mCRPC, CTCs likely emanate from bone metastases. Herein, we wished to establish a sensitive method to analyze gene expression in BMBxs and CTCs and to determine whether potential biomarkers present in bone lesions are mirrored in CTCs. METHODS Areas of relatively pure prostate cancer tissue were collected from BMBxs using laser capture microdissection. CTCs were enriched from blood using the CellSearch® platform. RNA from these two sources was amplified linearly using an Eberwine-based procedure to obtain antisense mRNA (aRNA). In this pilot study, the expression of 8 genes was assessed using RT-PCR. In control experiments, the efficiency of CTC isolation and linearity of RNA amplification were determined by comparing relative gene expression levels in non-amplified RNAs from large numbers of cultured PC3 cells and amplified aRNAs from small numbers of PC3 cells spiked in normal blood and recovered using the CellSearch® system. RESULTS RNAs were successfully extracted from as few as 1-5 CTCs in blood samples. The relative expression levels of reference genes were maintained after RNA amplification. The integrity of the amplified RNA was demonstrated by RT-PCR analysis using primer sets that target the 5′-end, middle, and 3′-end of reference mRNAs. Besides epithelial- and prostate-specific genes, Interleukin-6 was the only gene expressed in all CTCs analyzed. In this pilot study, we found partial concordance between gene expression patterns in CTCs and microdissected prostate cancer tissue from bone metastases of the same patients. CONCLUSIONS aRNA amplification through in vitro transcription may serve as a useful method for gene analysis in small numbers of CTCs and tumor cells microdissected from BMBxs. To our knowledge, this is the first comparative study of gene expression in CTCs and BMBxs from individual mCRPC patients. Our exploratory study in this small cohort of patients suggests that molecular analysis of CTCs might reveal gene expression patterns that might be missed by analysis of single BMBx sites. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e764-e765 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Won-Jin Cho More articles by this author Michael Cher More articles by this author Daniel Oliveira More articles by this author Abdo Najy More articles by this author Leandro Mainetti More articles by this author Elisabeth Heath More articles by this author Kim Hyeong-Reh More articles by this author R. Daniel Bonfil More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...