Glyceraldehyde-3-phosphate dehydrogenase as a surface associated antigen on human breast cancer cell lines MACL-1 and MGSO-3.

Breast cancer is a major health burden, responsible for >10% of all cases of cancer worldwide. Advances in breast cancer diagnosis and treatment have contributed to an improved rate of survival, although mortality rates remains significantly high. The establishment of breast cancer cell lines is an important model for understanding biological processes involved in this disease and for identifying potential therapeutic targets. The novel human breast cancer cell lines, MACL-1 and MGSO-3, were used in this study to identify possible surface antigens by antibodies directed against two commercial breast cancer cell lines MCF-7 and MDA-MB-231. We purified a 37 kDa antigen by affinity chromatography from MDA-MB-231, and its N-terminal amino acid sequence was homologous to glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Therefore, immunohistochemical experiments, using specific monoclonal antibodies, evidenced a co-localization of GAPDH and Na+/K+-ATPase on the surface of commercially available and recently established breast cancer cell lines. It is of note that Na+/K+-ATPase was used as a plasma membrane marker. This finding opens new perspectives for breast cancer diagnosis and treatment since GAPDH could be used as a biomarker or as a potential therapeutic target in breast cancer.