Basic Research - Cancer(구연) Oral Session1 / Basic Research - Cancer (Ⅰ) (O-003) Rm.201 10월 30일(수) 13:00-14:00 Urine-based liquid biopsy: non-invasive andsensitive AR-V7 detection in urinary EVs frompatients with prostate cancer 부산대학교 의과대학 비뇨의학과교실 구자윤, 김경환, 박지훈, 강병진, 박시균, 이권경, 하홍구 Objective: To develop a practical liquid biopsy method for detection of AR-V7 in urine-derived exosomal RNA by digital droplet polymerase chain reaction (ddPCR), without the need for blood withdrawal and to determine its clinical significance in patients with prostate cancer. Design, setting, and participants: Urine samples were collected from 22 hormone-sensitive prostate cancer (HSPC) patients and 20 CRPC patients. Urine-derived exosomes are isolated, and their RNA were extracted, and mRNA expression levels were quantified by ddPCR. Outcome measurements and statistical analysis: AR-V7 and androgen receptor full length (AR-FL) mRNA levels in urinary exosomes were quantified by ddPCR in absolute concentration as copies per milliliter (copies/mL). Discrimination power was evaluated using receiver operating characteristic (ROC) analysis. Statistical analyses were performed using GraphPad Prism version 7.0. Results and limitations: High AR-V7/AR-FL ratio and AR-V7 expression is detectable in urine-derived exosomes of 20 CRPC patients compared to 22 HSPC patients (AUC=0.80 with 95% CI 0.65-0.94, p < 0.01 and 0.66 with 95% CI 0.50-0.83, p < 0.5, respectively). Conclusions: This study is the first to demonstrate that urine-derived exosomal RNA is a reliable source of AR-V7 analysis. Testing AR-V7 mRNA levels in urine is a simple and promising approach to predict the resistance to hormonal therapy. keywords : AR-V7, Exosomes, Urine, Liquid biopsy