Effect of antiangiogenic treatment in head and neck tumor stem cells

Abstract

Tumor growth is dependent on angiogenesis and drugs with antiangiogenic effects have been studied in the treatment of various tumor types. However, only 10% of patients have responded to treatment with a single chemotherapy. Tumor stem cells (CTT) have been identified as responsible for metastasis, recurrence and resistance to chemotherapy. In this context, the definitive eradication of the tumor depends on the elimination of this cellular type. Objectives: The present study aims to evaluate the action of the combined chemotherapy drugs Bevacizumab and Paclitaxel on CTT derived from head and neck cancer (CCP). The specific objectives are: 1) To identify and separate the CTT of the cell line HN13, from oral cavity carcinoma; 2) To evaluate the gene and protein expression of vascular endothelial growth factor A (VEGFA) in CTT and to compare it with expression in non-stem tumor cells; 3) To verify the efficacy of the chemotherapy drugs Bevacizumab and Paclitaxel in CTT and non-stem cells of cell line HN13; 4) To evaluate in vitro the effect of chemotherapeutics on angiogenesis in CTT and non-stem cells. Material and Methods: Cells of the HN13 cell line will be cultured and separated by Flow Cytometry using the stem cells surface markers of CD44, CD117 and CD133. Both populations of cells will be submitted to the evaluation of the tumorigenic potential by means of tests of spheres formation, of invasion and migration, to confirm the presence of CTT. The VEGFA gene expression will be analyzed by real-time quantitative PCR and protein expression by ELISA. After these steps, the two cell populations will be treated with Paclitaxel and Bevacizumab and with the combination of the two chemotherapeutics for 24 hours. Cell viability and angiogenesis will be assessed after treatment. Expected results: The present study may contribute to a better understanding of the mechanisms still unknown in the tumorigenesis and chemoresistance processes and to help in the customization of treatments for head and neck cancer, making them more effective. (AU)