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Disparity in expression of CYP1A1 and CYP1B1 and their response to dioxin and benzo[a]pyrene in human mammary epithelial cells from pre‐menopausal African American and Caucasian women
Author(s) -
Goode Gennifer,
Humphrey Andria,
Prins Petra,
Eltom Sakina
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.921.1
Subject(s) - cyp1b1 , breast cancer , aryl hydrocarbon receptor , benzo(a)pyrene , carcinogen , medicine , western blot , cancer , gene expression , incidence (geometry) , endocrinology , gene , cancer research , biology , physiology , cytochrome p450 , genetics , physics , metabolism , transcription factor , optics
Although the overall breast cancer (BC) incidence rate for African American (AA) is lower than Caucasian (CA) women, among AA women under the age of 45 the rates are higher. Due to their roles in activation of environmental chemicals to ultimate carcinogens, the products of CYP1A1 and CYP1B1 genes are implicated as risk factors for breast cancer. The objective of this study is to examine the hypothesis that higher incidence of breast cancer in pre‐menopausal AA women is related to a disregulated expression of CYP1A1 & CYP1B1 genes. Our laboratory have isolated and characterized primary cultures of mammary epithelial cells (HMEC) of age‐matched pre‐menopausal AA and CA women, using normal breast tissues from mammoplastic reduction surgery. CYP1A1 & CYP1B1 expression in response to dioxin and benzo[a]pyrene (B[a]P) was measured by real time RT‐PCR in HMEC of ten age matched women donors. RT PCR results showed a marked difference in the expression of CYP1A1/CYP1B1 between AA and CA women in response to dioxin and B[a]P, which correlated to the levels of the Aryl hydrocarbon receptor. Western blot analysis of microsomal CYP1A1 protein showed no correlation to the mRNA expression in AA donors. These findings may contribute to a better understanding of differential role of environmental chemicals on the biology of breast cancer in this ethnic minority group. Supported by RR03032 15, CA91408‐01 and DAMD17‐02‐01‐0483 grants.