Abstract
Introduction: Breast cancer (BC) is the most common female malignancy worldwide. For the definitive treatment of MC, radiotherapy can be used, as an important component, and uses ionizing radiation (IR). Studies reveal the potential capacity of IR to promote metastasis. The clinical response of BC to radiotherapy is related to radiosensitivity and resistance of irradiated cells, which is associated with clonogenic activity and sensitivity to radiation. Unsuccessful treatment increases the risk of local and distant recurrence.Methodology: Three breast cell lines (MCF-10A, MCF-7, and MDA-MB-231) were irradiated with 2 Gy and after 72 hours following markers were evaluated: E-cadherin, fibronectin, vimentin, and Snail. The processes of invasion, degradation of MMP2 and MMP9, and transendothelial migration were then assessed. Double-strand DNA breaks (DSBs), apoptosis, and colony formation were quantified. Result: The detection of γH2AX histone of irradiated cells showed that MCF-10A non-tumor cell is more radiosensitive while the MDA-MB-231 tumor cell is more radioresistant. The dose 2 Gy altered the formation of colonies to any of the cell lines. Tumorigenic cells exhibited a markedly increase in apoptosis, 24 h after irradiation while MCF-10A cells only after 72 h. A single dose of 2 Gy does not induce changes in the cellular microenvironment that lead to changes in the mesenchymal epithelium in breast BC.Conclusion: A dose of 2 Gy induces apoptosis and consequently an alteration in cell survival. However, a single dose of 2 Gy does not induce changes in the cellular microenvironment that lead to changes in the mesenchymal epithelium.