Extracellular vesicles, mediators of tumor stromal crosstalk, in thyroid tumor microenvironment

Ciudad Autónoma de Buenos Aires

Congreso; Reunión Conjunta de Sociedades de Biociencias; 2017

The tumor microenvironment (TME) comprises multiple cellular and non-cellular components that converge to promote tumorigenesis in a variety of solid malignancies. Extracellular vesicles (EVs) have been implicated in cell-cell communication in tumor and distant microenvironments. In preliminary studies, we found that thyroid tumor cell-fibroblast interactions promoted the secretion and activation of matrix metalloproteinases (MMPs) and a migratory phenotype in tumor cells. CD147, a transmembrane glycoprotein implicated in MMPs expression, has been related to thyroid tumor progression. Our goal was to identify EVs production and their CD147 expression as mediators of malignant progression in thyroid TME. As an in vitro tumor-stroma cell interaction model, non-tumor cells (N-Thy-Ori), thyroid papillary carcinoma cells (TPC-1) and thyroid anaplastic cells (8505c) were co-cultured with normal fibroblasts (Fb). Cellular CD147 expression was analysed by FACS in isolated and co-cultured cells. EVs secretion and size, in cell and cell-Fb conditioned media (CMs), were characterised by Transmission Electronic Microscopy (TEM) and Dynamic Light Scattering. Isolated EVs were analysed for differential total protein expression by SDS-PAGE and Coomasie-Blue staining, and for CD147 expression by western blotting and gold-immunocytochemistry. CD147 expression showed no differences in thyroid isolated and co-cultured cells while increased in co-cultured Fb, irrespective of the thyroid cell used. Isolated EVs from CMs ranged between 50-600nm. In SDS-PAGE, an extra protein band was detected in EVs from TPC-1-Fb and N- ThyOri-Fb co-cultures. CD147 expression in EVs increased in TPC-1-Fb and 8505c-Fb co-cultures, without significant changes in N-ThyOri-Fb co-cultures. The results suggest that EVs-CD147 could play an active role in intercellular communication events in thyroid TME, stimulating the release of MMPs and the consequent migration and cellular invasion.