Carcinogenesis Advance Access published online on January 6, 2005
Carcinogenesis, doi:10.1093/carcin/bgi013
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Chemical Carcinogenesis Section, Laboratory of Experimental Carcinogenesis, Center for Cancer Research, National Cancer Institute, National Health of Institutes, Bethesda, Maryland, 20892
* To whom correspondence should be addressed. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a mammary gland carcinogen present in the human diet. Herein, the expression of estrogen receptor alpha (ER
Received October 25, 2004
Revised December 13, 2004
Accepted December 18, 2004
CANCER BIOLOGY
Steroid hormone receptor expression and proliferation in rat mammary gland carcinomas induced by 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine
Elizabeth G. Snyderwine, E-mail: elizabeth_snyderwine{at}nih.gov
Abstract 
), estrogen receptor beta (ER
), and progesterone receptor (PR) was examined in mammary gland carcinomas induced by PhIP in female Sprague-Dawley rats. Quantitative real-time polymerase chain reaction demonstrated that ER, ER and PR were statistically elevated by 3-, 4- and 8-fold in carcinomas compared to normal mammary glands. By immunohistochemistry, carcinomas showed statistically higher nuclear expression of all three steroid receptors with the majority of carcinomas showing at least 10% of epithelial cells stained for ER (49/55, 89%), ER (41/55, 75%) and PR (48/55, 87%). Furthermore, the level of expression of the three steroid hormone receptors was positively correlated with one another across the bank of carcinomas (Spearman analysis, p < 0.05). ER expression in carcinomas was associated with tumor grade, extent of nuclear pleomorphism, and cellular proliferation as measured by proliferating cell nuclear antigen (PCNA) and phospho-Rb immunostaining (Spearman analysis, p < 0.05). Confocal microscopy was used to measure the percentage of epithelial cells showing nuclear colocalization of receptors, PCNA, and cyclin D1. Colocalization of the receptors, and the colocalization of the receptors with PCNA and cyclin D1 was strikingly higher in carcinomas than in normal mammary gland. In carcinoma cells, 37% of ER positive epithelial cells were colocalized with PCNA in contrast to just 0.25% of cells in the normal mammary gland. The findings from this study indicate that ER, ER and PR were co-upregulated and nuclear localized in epithelial cells from rat mammary carcinomas compared to normal mammary glands, and that the co-upregulation was positively correlated with proliferation and cell cycle progression in carcinomas.); estrogen receptor beta (ER); progesterone receptor (PR); heterocyclic amines; breast; proliferation; carcinogenesis.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  E. Linos, W. C. Willett, E. Cho, G. Colditz, and L. A. Frazier Red Meat Consumption during Adolescence among Premenopausal Women and Risk of Breast Cancer Cancer Epidemiol. Biomarkers Prev., August 1, 2008; 17(8): 2146 - 2151. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Cho, W. Y. Chen, D. J. Hunter, M. J. Stampfer, G. A. Colditz, S. E. Hankinson, and W. C. Willett Red meat intake and risk of breast cancer among premenopausal women. Arch Intern Med, November 13, 2006; 166(20): 2253 - 2259. [Abstract] [Full Text] [PDF]
|
|