Role of S100A8 and S100A9 proteins on breast cancer aggressivity

Abstract

Women are more affected by breast cancers than any other type of cancer. Studies show that proteins from the S100 family are differentially expressed in cancers and autoimmune disease. The S100 protein family is the largest family of calcium binding proteins where most members are overexpressed in certain types of cancers. More specifically, S100A8 and S100A9 seem to be overexpressed in mammary ductal carcinomas. Nevertheless, little is known on the cellular effects of S100 proteins and their roles in breast cancer pathogenesis.In this study, we assessed cancerous biological processes (proliferation, apoptosis, cell adherence and ECM invasion) in mammary cells following: 1) the treatment with various concentrations of recombinant and purified S100A8 and S100A9 proteins and, 2) the knocked‐up or knocked‐down expression of the S100A8 and S100A9 genes. We found that extracellular treatments with S100 proteins affected growth rates of cancer cells. We also observed that the conditioned expression of S100 protein in breast cancer cells affected cancer processes in a cell type dependent manner. Details from these results will be discussed here.These results will aid to a better understand the roles of S100A8 and S100A9 proteins in epithelial cell biology and breast cancer pathogenesis. The outcome of these experiments could potentially lead to a better diagnostics or more specialized treatments of breast cancers.