Oxalate induces breast cancer tumor

ANDRÉS M. CASTELLARO; ALFREDO TONDA; HUGO H. CEJAS; HÉCTOR FERREYRA; BEATRIZ L. CAPUTTO; OSCAR A. PUCCI; GERMÁN A. GIL

Rosario

Congreso; SAIB; 2014

Microcalcifications are routinely used to detect breast cancer in its early stages. Mammary microcalcifications are mainly composed of calcium oxalate (OX) or calcium phosphate. In order to study the biological significance andimplication of OX within the breast tumor microenvironment, we measured Ox concentration in Human Breast tumor tissue and in adjacent non-pathological breast tissue. We found that all breast tumor tissues tested contained a higherconcentration of Ox than their counterpart non-pathological breast tissue. Moreover, Ox induced cell proliferation and over-expression of the pro-tumorigenic gene c-fos in cultured MCF-7 and MDA-MB231 human breast cancercells. Finally, when female mice received an injection of OX periodically in the mammary fat pad or in the back, only the mice injected with OX solution at the mammary fat pad area generated tumors indicating oxalate´s tissue specificity. Since no tumor formation was observed when oxalate was injected into mice back. Cell line specificity was also observed in vitro; non-breast cell lines did not proliferate nor expressed c-Fos when oxalate was added to the culture. Our results support the hypothesis that the chronic exposure of breast epithelial cells to OX promotes the transformation of breast cells from normal to tumor cells.