You have accessJournal of UrologyKidney Cancer: Basic Research & Pathophysiology I (MP39)1 Sep 2021MP39-13 FUNCTION OF EXOSOMAL ANTITUMOR MICRORNA-1 IN RENAL CELL CARCINOMA Issei Kawakami, Hirofumi Yosino, Hideki Enokida, and Masayuki Nakagawa Issei KawakamiIssei Kawakami More articles by this author , Hirofumi YosinoHirofumi Yosino More articles by this author , Hideki EnokidaHideki Enokida More articles by this author , and Masayuki NakagawaMasayuki Nakagawa More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002054.13AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: MicroRNAs, a class of small non-coding RNAs about 22 nucleotides in length, are involved in many cellular processes and aberrantly expressed in cancer tissues. For example, miR-1 functions as a tumor suppressor in renal cell carcinoma (RCC) as demonstrated in our previous study. Exosomes are 40–100 nm nano-sized extracellular vesicles, and are receiving increasing attention as novel structures participating in intracellular communication. We hypothesized that miR-1 functions as a tumor suppressor through exosomes in RCC, and investigated that in this study. METHODS: First, we performed statistical analyses of miR-1 based on the TCGA database of clear cell RCC (ccRCC) patients. We also checked miR-1 expression in serum exosomes between healthy controls and RCCs. Exosomes in cell lysate and human serum were isolated by a spin column-based method, and determined using Nanosight nanoparticle tracking analysis and western blot analysis with exosome marker CD63. Exosomes labeled with PKH26 were used to indicate that exosomes were fused into recipient cells, and miR-1 expressions were investigated by RT-PCR in recipient RCC cells with the addition of miR-1 transfected cell derived exosomes. By using the recipient RCC cells, we performed functional analyses such as proliferation, migration and invasion. We also performed functional analyses by using serum exosomes derived from RCC patients with IVC invasion or metastasis. In addition, we performed RNA sequence analyses to identify the mechanism in RCC cell with the addition of exosomal miR-1. RESULTS: MiR-1 expression was significantly downregulated in clinical ccRCC samples compared to that in normal kidney samples (p<0.001), and patients with low miR-1 expression (n=455) had poor overall survival (p=0.0447) in comparison to patients with high expression (n=50). Exosomes in cell lysate and human serum were detected by Nanosight and western blot analysis with CD63. Exosomes labeled with PKH26 were detected in the recipient cells, and miR-1 expressions were elevated nearly 40 and 10 times in exosomal miR-1 fused 786o and A498 cells respectively compared to in exosomal miR-control fused cells. Exosomal miR-1 also significantly inhibited cell proliferation, migration and invasion compared to exosomal miR-control. Furthermore, RNA sequence analyses showed that several genes and pathways might be regulated by exosomal miR-1. CONCLUSIONS: This study showed that exosomal miR-1 might exogenously function as a therapeutic target in the treatment of RCCs. In addition, exosomal miR-1 and/or other miRNAs could be a diagnostic tumor marker of RCCs. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e709-e709 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Issei Kawakami More articles by this author Hirofumi Yosino More articles by this author Hideki Enokida More articles by this author Masayuki Nakagawa More articles by this author Expand All Advertisement Loading ...