Two-dimensional electrophoretic comparison of metastatic and non-metastatic human breast tumors using in vitro cultured epithelial cells derived from the cancer tissues

We prepared primary cultures of epithelial cells from 23 breast cancer tissue samples and performed comparative proteomic analysis. Seven patients developed distant metastases within three-year follow-up. These samples were included into a metastase-positive group, the others formed a metastase-negative group. Two-dimensional electrophoretical (2-DE) gels in pH range 4–7 were prepared. Spot densities in 2-DE protein maps were subjected to statistical analyses (R/maanova package) and data-mining analysis (GUHA). For identification of proteins in selected spots, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed.Three protein spots were significantly altered between the metastatic and non-metastatic groups. The correlations were proven at the 0.05 significance level. Nucleophosmin was increased in the group with metastases. The levels of 2,3-trans-enoyl-CoA isomerase and glutathione peroxidase 1 were decreased.We have performed an extensive proteomic study of mammary epithelial cells from breast cancer patients. We have found differentially expressed proteins between the samples from metastase-positive and metastase-negative patient groups.Breast cancer is the most common cancer affecting women worldwide. Human breast carcinomas represent a heterogeneous group of tumors diverse in behavior, outcome, and response to therapy. Despite tremendous advances in screening, diagnosis, and treatment, causes of this disease remain elusive and complex.It has been hypothesized that the clinical and genetic heterogeneity of breast cancer is a result of activation of different oncogenes or loss of different tumor suppressor genes in specific stem/progenitor cells [1]. The genetic and immunohistochemical analysis led to further clasification of human breast cacinomas as basal or luminal according to their cell type origin. To date, five types of breast carcinomas have been recognized according to the molecular genetics profiling [2,3].The nature of molecular chang