The Study Of Effects Of HRT And Phytoestrogen (NH1996) On Human Breast

Objectives: (1) To study the effects of estradiol benzoate (B-E2) and phytoestrogen nature hormone 1996 (NH1996) on normal human breast on the level of histology, molecular, and gene expression. (2) To investigate the effects of conjugated equine estrogen (CEE) in different doses combined with medroxyprogesterone acetate (MPA) on mammographic density among postmenopausal women, and to assess the clinical significance.Methods: Basic experiment studies include three parts. Experiment one: The nude mice xenograft models of normal human breast tissues that were subcutaneously implanted into 9-to 10- week-old athymic nude mice were established. Two and six weeks after implanting, the specimens of grafts without hormone administration were taken out. Then, the volume and morphology of grafts were observed and proliferating cell nuclear antigen (PCNA) expression of mammary epithelial cells in grafts was detected by immunohistochemistry. Experiment two: From 2 to 6 weeks after implanting, B-E₂ or NH1996 with respective dosage of 20ug and 100ug were injected muscularly into four groups of host mice once two days, and the control group was designed without treated with hormone. All breast tissues were taken out at 6 weeks after implanting. The protein expressions of PCNA, inhibiting apoptosis gene Bcl-2, estrogen receptor (ER) and progesterone receptor (PR) of mammary epithelial cells in all of grafts were determined by immunohistochemistry at six weeks after implanting. The volume and morphological character of grafts pre-to post-treatment were observed as well. Experiment three: The expression levels of estrogen sulfotransferase (EST) mRNA and bridging integrator protein-1 (BIN1) mRNA in normal human breast tissues of grafts and in normal breast and breast cancer tissues obtained additionally were measured by reverse transcription polymerase chain reaction (RT-PCR).