Abstract 879: Exosomal mRNAs secreted from pancreatic cancer (PC) cell lines might include good candidates of biomarkers of PC patients

Abstract Background: Exosomal mRNAs secreted from cancer cells are regarded as important messengers in communication system between cells. In PC, some exosomal RNAs from patients’ plasma were expected as biomarkers of PC. However, exosomes in the blood of cancer patients are not derived only from cancer cells. Relationship of RNAs produced in cancer cells and those secreted into exosomes is still unclear. In this study, we evaluated relationships between mRNAs in PC cell lines and those of exosomes secreted into supernatant and determined candidates for PC biomarkers from cancer specific exosomal mRNAs. Material and Method: Three PC cell lines (PANC-1, MIAPaCa-2 and Capan-1) were used. Three studies were performed for each cell line. After 48h serum-free culture, the supernatants were collected, and exosomes were isolated by ultracentrifugation. The remaining cells in the culture dish were also collected and mRNAs were extracted. RNA-seq was performed for mRNAs extracted from cell and exosomal RNAs extracted from supernatant. Data was analyzed by R (version 4.2.1). Results: In MIAPaCa-2, expression of cellular mRNAs and corresponding exosomal mRNAs showed strong correlation (R was higher than 0.7). In the other 2 cell lines, they showed moderate correlation (R was higher than 0.5). Then, expression of mRNA in the cells was approximately reflected in those in the exosomes. However, some mRNAs showed high expression in exosome and low expression in the cell. We focused on these mRNAs, and then, performed a differential analysis of the whole raw RNA data by using TCC package of R and found differentially expressed mRNAs. Conclusion: Comparing with data of GEO database showing exosomal mRNA extracted from healthy volunteers, we finally find candidates of cancer specific exosomal mRNAs of PC. Citation Format: Yuhan Rong, Naoki Okubo, Risa Fukui, Akihiro Suzuki, Motokazu Sato, Motohiko Tokuhisa, Yuma Takeda, Noritoshi Kobayashi, Itaru Endo, Yasushi Ichikawa. Exosomal mRNAs secreted from pancreatic cancer (PC) cell lines might include good candidates of biomarkers of PC patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 879.