The Effect of Ionizing Radiation on MCF-7 Breast Cancer Cell Line

Abstract

Background and Objectives Breast cancer is one of the most common cancers worldwide. Radiotherapy is widely applied for breast cancer treatment, however, cancer cells resistance to ionizing radiation (IR) causes problems for the best treatment outcomes. The evidence suggests that some chemical substances in combination with IR could generate synergistic effect and increase death of cancerous cells. Mefenamic acid (MEF) is one of non-steroidal anti-inflammatory drugs. Literature sources present the data of MEF potential to improve the radio-sensitization of cancer cells. However, this type of analysis has never been done on breast cancer cells. Lithuanian University of Health Sciences participates in Horizon 2020 project "INfraStructure in Proton International Research" (INSPIRE) in the Framework Programme for Research and Innovation. In INSPIRE project we aimed to analyze the molecular basis of breast cancer cell resistance to ionizing radiation. Consequently, the aim of this study was to determine the radiation-induced effects on MCF-7 breast cancer cells in vitro and to analyze the effect of different MEF concentrations on breast cancer cell proliferation. Material and Method Human breast cancer cell line MCF-7 was used for the study. Cells were exposed to 2, 4, 6, 8, 10 Gy of IR from Clinac 2100C/D linear accelerator. Radiation-induced effect was assessed using colony formation, apoptosis and cell-cycle assays. To determine the effect of MEF, MCF-7 cell proliferation was estimated using MTT assay. The powders of MEF were dissolved in dimethyl sulfoxide (DMSO) to achieve a concentration of 178 mM of stock solution. The stock solution was frozen at -20°C in small quantities to prevent freeze-thaw cycles. Working solutions were prepared before each experiment. Final DMSO concentration was 0.28 % in all the samples. Exponentially growing cells were plated into 96-wells plates for 24 hours and th... [...].