STARVATION-INDUCED AUTOPHAGY MODIFIES THE EXOSOMES COMPOSITION FROM PANCREATIC CANCER CELLS

NADIA PAGLILLA; DANIEL GRASSO; MARIA NOÉ GARCIA; ESTEFANÍA S. PAPARATTO; ELIDA ALVAREZ; TOMÁS LOMBARDO; DANIELA L. PAPADEMETRIO

Mar del Plata

Congreso; S A I C . S A F E . S A B . SAP 2 0 1 9; 2019

Sociedad Argentina de Investigación Clínica

Pancreatic adenocarcinoma (PDAC) is a highly deathly cancer with neither a prognostic marker nor effective treatment. Exosomes are 50-130 nm extracellular vesicles that are released from most tissues, although their composition is in close relation with the origin cell. These vesicles are important mediators of intercellular communications and play pivotal roles in cancer progression, metastasis and chemoresistance. Tetraspanins are widely accepted exosomal markers (CD63, CD9, CD81). Recent publications suggest a close relationship between exosomes release and the autophagy pathway.The aim of this work was to evaluate tetraspanins composition in exosomes from PDAC cells in response to starvation as a physiological autophagy inductor. Total exosomal fractions were purified from MiaPaca2 and Panc1 PDAC cell lines by ultracentrifugation. Then, specific exosomes populations were selected by different antibodies against tetraspanins attached to magnetic beads. Eventually, bead-bound exosomes are probed for specific markers and analyzed by flow cytometry. We observed a significant increase of the exosomal marker CD63 upon 1h starvation versus basal condition in CD9+ vesicles (MFI, MiaPaca2: 183.2 vs. 97.8, p