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Correlation of p27 protein expression with HER‐2/neu expression in breast cancer
Author(s) -
Newman Lisa,
Xia Weiya,
Yang HengYin,
Sahin Aysegal,
Bondy Melissa,
Lukmanji Farzana,
Hung MienChie,
Lee MongHong
Publication year - 2001
Publication title -
molecular carcinogenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 97
eISSN - 1098-2744
pISSN - 0899-1987
DOI - 10.1002/mc.1025
Subject(s) - breast cancer , immunohistochemistry , biology , downregulation and upregulation , cancer research , oncology , cancer , medicine , correlation , protein expression , immunology , gene , biochemistry , genetics , geometry , mathematics
Strong expression of human epidermal growth factor receptor 2 (HER‐2)/neu in breast cancer has been associated with poor prognosis. Reduced expression of p27 Kip1 , a cyclin‐dependent kinase inhibitor, correlates with poor clinical outcome in breast cancer. In this study, we provide a correlation between these two important prognostic markers in patients with breast cancer. Breast tumor screening using immunohistochemistry indicated that downregulation of p27 correlated with HER‐2/neu overexpression in studying 11 normal breast tissues and 51 primary breast carcinomas. We found HER‐2/neu protein overexpression in 20 (41%) of 49 breast cancers and low p27 protein expression in 47 (92%) of 51 breast cancers. All 20 (100%) of the tumors that overexpressed HER‐2/neu had low levels of p27 protein product; this correlation was statistically significant ( P = 0.035). Decreasing p27 expression correlated with increasing HER‐2/neu activity. Our results suggest that one function of the HER‐2/neu product is to downregulate p27 expression in breast cancer. This study may be significant in selecting patients for HER‐2/neu antibody therapy in the future. Mol. Carcinog. 30:169–175, 2001. © 2001 Wiley‐Liss, Inc.