Proteome analysis of breast cancer cells (8701-BC) cultured from primary ductal infiltrating carcinoma: relation to correspondent breast tissues

Abstract

The two-dimensional gel electrophoresis represents a unique tool of analysing expression levels of a thousand proteins simultaneously and to compare the protein profiles of a given cell a worldwide dimension. In addition, the recent programs developed for cross-comparing gel images, even from different laboratories, offer the possibility to evaluate homologies and differences between affine maps. By Melanie-assisted analyses and access to Swiss-2DPAGE database, we have detected the proteomic profile of the 8701-BC cell line, deriving from a primary DIC, which represents the most common type of breast cancer. The cell-line map was compared by gel matching with that of DIC biopsy available on line, and within the large area of overlapping, some of the corresponding spots were identified and quantified. To our knowledge this is the first attempt to correlate the pattern of protein expression of a cell line derived from a primary tumor with the corresponding tissue. The results are of great interest from at least two point of view: firstly, the 8701-BC cell line retains the dominant luminal phenotype of the breast epithelium, which expresses predominantly cytokeratins -8 and -18; secondly the proteomic profile of the cell line appears highly homologous to the in vivo counterpart. In particular, a panel of 28 peptides, showing a higher expression the DIC tissue with respect to the normal counterpart, displays the same, or even more robust signature the cancer cells. This group of peptides, mainly belonging to stress protein family and to metabolic enzymes, may be considered as tumor markers of peculiar pertinence of neoplastic cells, rather than of stromal components, and representative, if not exclusive, of breast carcinoma.