EXTRACELLULAR VESICLES, MEDIATORS OF TUMOR STROMAL CROSSTALK, IN THYROID TUMOR MICROENVIRONMENT.

RIO DE JANEIRO

Congreso; LATIN AMERICAN THYROID CONGRESS; 2017

The tumor microenvironment (TME) comprised multiple cellular and non-cellular components, that converge to promote tumorigenesis in a variety of solid malignancies. Non-classical secretory vesicles, collectively referred to as extracellular vesicles (EVs), have been implicated in cell-cell communication in tumor and distant microenvironments. In preliminary studies, thyroid tumor cell-fibroblasts (Fb) interaction promoted the secretion and activation of matrix metalloproteinases (MMPs) and tumor cell migration. CD147, a transmembrane glycoprotein implicated in MMPs expression, plays a crucial role in tumorigenicity, invasion and metastasis. Our goal was to identify potential mechanisms of thyroid cancer progression in the context of the TME. As an in vitro tumor-stroma cell interaction model, non-tumor cells (N-ThyOri), thyroid papillary carcinoma cells (TPC-1) and thyroid anaplastic cells (8505c) were co-cultured with normal Fb. Cellular CD147 expression was analysed by FACS in isolated and co-cultured cells. EVs secretion and EVs 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 utilized. Isolated EVs from CMs ranged between 50-600nm. A particular extra band was detected in EVs from TPC-1-Fb and N-ThyOri-Fb cocultures. 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.