Protein profiling and transcript expression levels of heat shock proteins in 17β-estradiol-treated human MCF-7 breast cancer cells

Using proteomics, proteins regulated by 17 beta-estradiot (E2) were identified in human MCF-7 breast cancer cells; 26 proteins including heat shock proteins (Hsps) were differentially regulated by E2 in cells cultured in serum-free condition. When the transcript levels of these proteins and another Hsps were measured by real-time PCR, the transcripts encoding 6 proteins (Hsp56, Hsp90 alpha, Hsp110, protein disulfide isomerase related protein, XTP3-transactivated protein A and stathmin 1) were significantly up-regulated and that encoding aminoacylase 1 was down-regulated by E2 in cells cultured with or without serum. The protein profiling and transcript expression patterns of E2-regulated proteins including Hsps in MCF-7 cells suggested the involvement of these proteins in breast carcinogenesis. Proteins (or transcripts) whose expression pattern is altered by E2 might be potent targets for treating breast cancer patients. (c) 2006 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.