Abstract 4444: The role of small GTPase Rab7 in the secretion of extracellular microvesicles by head and neck squamous cells carcinoma

Head and neck squamous cell carcinoma (HNSCC) is an epithelial malignant tumor that shows its highest incidence in the upper aerodigestive tract and is considered one of the six most common malignancies worldwide. Among the processes involved in the poor prognosis of HNSCC, local invasion and subsequent metastasis are the most important events. Recent evidences have shown that metastasis can be the result of extracellular microvesicles (MVEs) being released from the tumor cells to the blood or lymphatic system. The molecular mechanisms involved in MVEs biogenesis and secretion are, however, poorly understood. Herein, we have performed a screen targeting for the components of MVEs biogenesis in three HNSCC cell lines (SCC-9, Cal27 and FaDu) through western blotting. MVEs were quantified using Nanoparticle Tracking Analysis (NTA - NanoSight®) and the lysosomal compartment was followed in the cell lines through immunofluorescence. Comparing the three cell lines, FaDu cells presented higher expression of proteins responsible for MVEs formation (p Supported by Sao Paulo Research Foundation (FAPESP) Citation Format: Fernanda S. Giudice, Bruna R. Rodrigues, Marcos V. S. Dias, Antuani R. Baptistella, Tonielli Cristina S. Lacerda, Luiz P. Kowalski, Vilma R. Martins. The role of small GTPase Rab7 in the secretion of extracellular microvesicles by head and neck squamous cells carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4444. doi:10.1158/1538-7445.AM2014-4444