Comparative analysis of gene expression profiles in basal-like carcinomas of the breast.

Objective: To compare basal-like breast carcinoma (BLBC) gene expression profiles to normal mammary epithelium in order to determine the characteristic gene expression patterns associated with the tumor.

Study design: The gene expression profiles of 12 cases of BLBC were analyzed using a human mRNA genome expression profiling chip containing 48,804 probes in an attempt to characterize molecular mechanism involved in the carcinogenesis of BLBC.

Results: The identified 99 genes were upregulated more than fourfold fold-change (FC) value over their levels in normal mammary ductal epithelial cells, and 43 genes were downregulated to less than fivefold FC value compared to normal epithelial cells. Verification of selected genes by semiquantitative reverse transcription polymerase chain reaction was performed to confirm the expression data obtained by microarray analysis. Most of the abnormal expressed genes were related to DNA binding, transcription and its factor, cell receptors, cell signals and transmitted proteins, metabolism-related proteins, and protein synthesis-related genes.

Conclusion: The difference of gene expression profiles might be of benefit for selecting the relative genes of the basal-like carcinoma as the therapy target and to further the understanding of the development of BLBC.