THYROID TUMOR CELLS-FIBROBLASTS INTERACTION PRODUCES EXTRACELLULAR VESICLES INVOLVED IN THYROID TUMOR AGGRESSIVENESS

BRAVO MIANA RC; NEGRETTI BORGA DANA; SOLER MF; DE PAUL AL; GILARDONI MB; MONTESINOS MM; PELLIZAS CG; DONADIO AC

Congreso; XVII Latin American Thyroid Congress; 2019

Carcinomas are complex societies of mutually interacting cells. Extracellular vesicles (EVs) mediate intercellular communication in the tumor microenvironment (TM). Metalloproteinases (MMPs) activity and Galectin-1 (Gal-1) expression in TM regulate tumor-stroma crosstalk leading to tumor progression and aggressiveness.We demonstrated that thyroid tumor cells-fibroblasts (Fb) interactions induce the secretion of MMPs to culture supernatants (CMs) and a migratory phenotype in tumor cells. To characterise EVs released by Fb and thyroid cells and their role mediating a thyroid tumor-promoting environment.Thyroid tumor cells (TPC-1, 8505c) or thyroid non-tumor cells (NThyOri) were co-cultured with normal human Fb as a simulation of the thyroid TM. EVs, obtained by ultracentrifugation of thyroid cell, Fb and thyroid cell-Fb CMs were characterised by Transmission Electron Microscopy and Western blot. MMPs activity was analysed by zymography in EVs, and in CMs from Fb and NThyOri cells incubated with EVs. Gal-1 expression was evaluated by RT-qPCR in EVs-stimulated Fb.Isolated and co-cultured cells secreted EVs to CMs. EVs have the characteristic cup-shaped morphology, size (<150nm), and CD81 and CD63 expression described for exosomes. EVs released by TPC-1-Fb co-cultures induced proMMP2 secretion and the significant MMP2 activation from Fb and NThyOri cells, as well as increased proMMP9 expression from NThyOri cells. Gal-1 mRNA expression increased in Fb stimulated with EVs from TPC-1-Fb co-cultures. These findings underpin the role of the interaction of thyroid tumor cells and Fb in tumor aggressiveness promotion and the EVs as contributors in this crosstalk.