Discovery of novel urinary biomarker of bladder cancer by proteomic analysis of urinary and tissue-exudative exosomes.

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K16788
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Urology
• Research Institution: Osaka University
• Principal Investigator: Matsuzaki Kyosuke 大阪大学, 医学系研究科, 招へい教員 (90747081)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: エクソソーム / 膀胱癌 / 尿 / バイオマーカー / proteomics

Outline of Final Research Achievements

Extracellular vesicles(EVs) were isolated from urine from 7 bladder cancer(BC) patients and 4 healthy controls(HC) by ultracentrifugation.We also extracted EVs directly from surgically resected viable BC tissues(tissue exudative EV;Te-EVs).EVs protein were labeled with TMT and analyzed by LC-MS/MS.We identified 1960 proteins in urinary EVs and 1538 proteins in Te-EV, among which CLD4 was detected in urine of only BC patients and was also enriched in Te-EV. CLD4 in urinary EVs was verified in 70 independent urine samples(BC[n=40],HV[n=30]) using SRM/MRM.CLD4 in urinary EVs was significantly higher in BC group than in HC group (fold-change=9.82, p-value )and was significantly associated with pT stage (p-value for trend <0.0001). The AUC was 0.845, and the sensitivity and specificity of the model at the best cutoff value were 72.5% and 86.7%, respectively.The diagnostic performance of CLD4 was better than that of urine cytology ((Youden's index 0.592 vs 0.475).

Free Research Field

尿路癌

Academic Significance and Societal Importance of the Research Achievements

今回の研究では、膀胱癌患者の尿中エクソソームに加え、癌組織から分泌される癌特異的エクソソームを同時に解析することで、より癌特異度の高いエクソソームを同定することができ、結果としてより有用なバイオマーカーを探索、同定することができた。このCLD4は膀胱癌のスクリーニングとして用いるだけでなく、癌組織から分泌されていることより、エクソソームを介して微小環境(microenvironment)を制御している可能性もあり、これを阻害することで新規治療薬の開発に直結する可能性もあると考えられる。