Role of Calcium in an Experimental Breast Cancer Model Induced by Radiation and Estrogen

<b>Background</b>: Breast cancer, a global health challenge, significantly impacts women worldwide, causing morbidity, disability, and mortality. <b>Objectives:</b> To analyze the role of genes encoding S100 calcium-binding proteins and their relationship with radiation as possible markers in breast carcinogenesis. <b>Methods:</b> The normal MCF-10F cell line was used to study the role of ionizing radiation and estrogen to induce distinct stages of malignancy giving rise to an in vitro experimental breast cancer model. <b>Results:</b> Analysis of an Affymetrix system revealed that the gene expression levels of the S100 calcium-binding protein P (<i>S100P</i>), the S100 calcium-binding protein A14 (S100A14), and the S100 calcium-binding protein A2 (<i>S100A2</i>) were greater in the Tumor2 than the non-tumorigenic Alpha3 or the tumorigenic Alpha5 cell lines; however, the S100 calcium-binding protein A8 (<i>S100A8</i>) and the S100 calcium-binding protein A9 (<i>S100A9</i>) expression levels were higher in A5 than T2 and A3 cell lines. A significant positive association was found between the estrogen receptor alpha gene (<i>ESR1</i>) and <i>S100A14</i> in Basal and Her2 patients. The association between <i>ESR1</i> and <i>S100A8</i> and <i>S100A9</i> expression levels was positive in Basal patients but negative in Her2, Luminal A, and Luminal B. <i>S100P</i> and <i>S100A14</i> expression levels were higher in tumor tissues than in normal ones. The estrogen receptor status was positive in patients with high levels of the <i>S10014</i> gene, but negative in <i>S100A2</i>, <i>S100A8</i>, and <i>S100A9</i> expression levels. <b>Conclusion:</b> Cell dependence needs to be considered while designing new breast cancer treatments since gene signatures might vary depending on the type of tumor.