Mammary gland morphological and gene expression changes underlying pregnancy protection of breast cancer tumorigenesis.

ABSTRACT: A full-term pregnancy early in life reduces lifetime risk of developing breast cancer, and the effect can be mimicked in rodents by full-term pregnancy or short-term treatment with exogenous estrogen and progesterone. To gain insight into the protective mechanism, 15 3-mo-old postpubertal virgin Lewis rats were randomly assigned to three groups: control (C), pregnancy (P), or hormone (H). The P group animals underwent a full-term pregnancy, and H group animals were implanted subcutaneously with silastic capsules filled with ethynyl estradiol and megesterol acetate for 21 days. C and P animals were implanted with sham capsules. On day 21 capsules were removed, which was followed by a 49-day involution period, euthanasia, and mammary tissue collection. Global gene expression was measured usi

SUBMITTER: Misra Y 

PROVIDER: S-EPMC4116391 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature