Effects of early exposure of new born rats to octylphenol on breast cancer incidence and BRCA1 expression
10.3781/j.issn.1000-7431.2008.08.008
- Author:
Jun-Hua PENG
1
Author Information
1. Department of Clinical Laboratory
- Publication Type:Journal Article
- Keywords:
Breast neoplasms;
Gene, BRCA1;
Octylphenol;
Receptor, estrogen
- From:
Tumor
2008;28(8):668-671
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To investigate the effects of early exposure of new born rats to octylphenol (OP) on breast cancer incidence and breast cancer susceptibility gene 1 (BRCA1) expression. Methods: Female Sprague-Dawley rats were randomly divided into control (Con) group, model (Mod) group, OP 20, OP 40, OP 80 groups. OP was subcutaneously injected into rats from d 21 to d 27. The rats were given dimethylbenz[a]anthracene (DMBA) intragastrically on d 42 and were sacrificed on 180 d. The incidence of breast cancer, the changes in serum levels of estradiol and progesterone, the alteration of estrogen receptor (ER) expression and BRCA1 mRNA and protein expression in breast cancer tissues were observed. Results: No breast cancer occurred in Con group. The incidence rate of breast cancer in the Mod group, OP 20 group, OP 40 group, and OP 80 group were 70% (14/20), 60% (12/20), 25% (5/20), and 50% (10/20), respectively. The fluorescence intensities of BRCA1 expression were 31.54 ± 6.15, 36.27 ± 7.57, 61.69 ± 9.96 and 47.38 ± 10.45, respectively; the logarithm value of BRCA1 mRNA expressions were 3.46 ± 6.52, 4.12 ± 0.86, 5.53 ± 0.75, and 4.35 ± 0.58, respectively. The ER expression in breast cancer tissues decreased after the rats were exposed to OP. Conclusion: OP decreased the occurrence of DMBA-induced breast cancers, which may be related with up-regulation of BRCA1 expression and down-regulation of ER expression in breast cancers.
