17HSD 2 may be Higher in African-American Breast Cancer and is Associated with Estrogen Receptor-negative Tumors

Abstract

Background: African-American women develop more aggressive breast cancers and at an earlier age compared with Caucasian women. Materials and Methods: We compared gene expression profiles of breast cancer cell lines that were developed from African-American and Caucasian patients to identify biological differences in breast cancers that develop in these groups. Real-time PCR was used to evaluate mRNA expression in cell lines and in a series of breast cancer cases. Gene microarray signal intensities were also analyzed in the International Genomics Consortium Expression Project for Oncology (expO) dataset. Results: 17β-Hydroxysteroid dehydrogenase type 2 (17HSD 2) gene and mRNA expression were significantly higher in the African-American cell lines (p<0.05). However, 17HSD 2 expression did not differ significantly between the two cohorts in either our clinical series or the expO dataset. 17HSD 2 expression was found to be predictive of younger age at diagnosis and estrogen receptor status. Conclusion: Overexpression of 17HSD 2 in African-American breast cancer may contribute to the increased proportion of estrogen receptor-negative breast cancers and worse clinical outcome among African-American patients.