Ns, at the same time as autophagy-related proteins like LC3 and p62, in the EV fraction from the culture media. We also located that inhibitor treatment facilitates secretion of EVs distinct from exosomes in size, and that these EVs are involved in secretion of ubiquitinated proteins. Interestingly, evaluation of knockout cells deficient for autophagy-related proteins revealed that the variables in the initiation step of autophagy are needed for EVmediated secretion of ubiquitinated proteins.ISEV2019 ABSTRACT BOOKSummary/Conclusion: These final results indicate that autophagy impairment promotes secretion of ubiquitinated proteins via EVs. Our data provide the mechanistic hyperlink involving the autophagy/lysosome pathway and vesicle secretion. We propose that cells could make use of the EV-mediated secretion as an alternative pathway to retain MMP Purity & Documentation protein homeostasis when cellular proteostasis machinery is functionally impaired. Funding: This function was supported by JST; by KAKENHI (18H02585); by The Asahi Grass Foundation plus the Tokyo Biochemical Study Foundation.miRNAs, four miRNAs altered the EV secretion in both cell lines, HCT116 and A549. Summary/Conclusion: A few of these target genes have reported as endosomal pathway related protein and shown the up-regulation in cancer cells. These findings recommend that the identification of target genes of those miRNAs offers the new insight into the cancer cell communication using the microenvironmental cells, which results in a promising therapeutic approach against cancer PAR1 list progression.PF07.04 PF07.Identifying the miRNAs linked with EV Secretion from cancer cell lines Tomofumi Yamamotoa, Nobuyoshi Kosakab, Fumihiko Urabea, Yutaka Hattoric and Takahiro Ochiyab Division of Molecular and Cellular Medicine, National Cancer Center Study Institute, Tokyo, Japan; bDepartment of Molecular and Cellular Medicine, Institute of Healthcare Science, Tokyo Medical University, Shinjyuku-ku, Japan; cClinical Physiology and Therapeutics, Keio University Faculty of Pharmacy, Tokyo, JapanaRas Tumour microvesicles biogenesis and signalling in drosophila Vakil Ahmad, Carson Broeker, Kayla Calandro and Yves Chiswili. Chabu University of Missouri, Columbia, USAIntroduction: Extracellular vesicles (EVs) derived from cancer cells contribute to their surrounding microenvironmental cells for their benefit. Our group has previously shown that inhibiting the EVs production attenuated the angiogenesis within the tumour, resulting inside the suppression of metastasis. Hence, understanding the mechanisms of EV secretion may contribute to the regulation of EVmediated cancer progression. However, the precise mechanism of EV secretion in cancer cells remains unclear. The purpose of this study would be to elucidate the unknown mechanisms of EV secretion in cancer cells. To reveal this, microRNAs (miRNAs), which regulate various genes, are employed. Methods: To identify the EV secretion related miRNAs, miRNA-based screening process was established. Combined with ExoScreen, which can be ultra-sensitive detection technique of EV by measuring surface protein of EVs, such as CD9 and CD63, miRNAbased screening was performed in colorectal cancer cell line, HCT116, and lung cancer cell line, A549. The results of your screening had been confirmed by the nanoparticle tracking analysis. Candidate genes of those miRNAs had been chosen by in silico analysis. Outcomes: From the initial 1728 miRNAs, we identified 13 miRNAs which are related with EV secretion in each and every cell lines. Then, the target.