B-CATENIN SIGNALING PATHWAY AND THE TOLERANCE OF BREAST CANCER CELLS TO HYPOXIC CONDITIONS

摘要

We have previously shown that Snail, a regulator ofepithelial-mesenchymal transition, is activated in the hypoxia-resistant breast cancer cell line HBL-100. The purpose of this study was to evaluate the role offi-catenin signaling pathway in the maintenance of breast cancer cells' tolerance to hypoxia. The breast cancer cell lines MCF- 7 and HBL-100 were used in this study; HBL-100 cells were characterized by increased resistance to hypoxia. We have demonstrated that the transcription factor fi-catenin is activated in hypoxic conditions and the fi-catenin activity is supported by Snail, a regulator of epithelial-mesenchymal transition. The activated fi-catenin regulates the expression of genes of the cell response to hypoxia and thus, it maintains the growth of breast cancer in the reduced oxygen conditions. The coordinated activation of Snail/beta-catenin/HlF-la proteins in cell may be considered as an important factor of tumor resistance to hypoxia.