In non-cancerous breast tissue from premenopausal women, we examined gene expression and protein levels of the androgen receptor and the proteoglycans decorin, syndecan-1 and syndecan-4, before and after use of oral contraceptives (OC).
Material and Methods
Premenopausal women (n = 20) undergoing breast reduction plastic surgery, received two months use of combined oral contraceptive with ethinylestradiol 30μg and levonorgestrel 150μg. Breast tissue was sampled at mammography (needle biopsy) two months before and at the operation. We analysed immunohistochemistry (n = 20) and real-time RT-PCR (n = 10).
After two months of OC use, we found a significant decrease in the protein levels of syndecan-4 (p = 0.003), the androgen receptor (p = 0.002) and decorin (p = 0.018), but not of syndecan-1 protein, compared to expression during the follicular phase in the normal menstrual cycle before OC use. Real- time RT-PCR indicated a significant decrease in gene expression for decorin (p = 0.002).
In pre-menopausal women, short-term OC use yielded lower protein levels of syndecan-4, the androgen receptor and decorin, and lower gene expression for decorin, compared to that during the follicular phase of the menstrual cycle before OC use.