Adult female rats were ovariectomized and treated with or without
estrogen for two weeks.
mRNA was obtained from the hypothalamus, uterus, liver, kidney and skeletal muscle and analyzed by Northern blotting and/or RT-PCR. We examined two types of
estrogen-responsive genes from rats, neuronal system-related genes (
Amphiregulin, AR;
Neuropeptide Y-Y1 receptor, NPY-Y1R; Bassoon, BSN;
N-Cadherin, N-CADH) and
estrogen-susceptible
cancer-related genes (
C-terminal binding protein interacting
protein, CtIP), based on the results of a
cDNA microarray analysis which was carried out to profile
estrogen-responsive genes in the human
breast cancer cell line MCF-7. The N-CADH gene showed identical response to that in MCF-7 cells. In the hypothalamus, all except the AR gene were down-regulated in their expression. In other tissues, the expression showed marked differences: expression of the BSN gene was not detected by either method, and the NPY-Y1R gene showed down-regulation in most tissues except for skeletal muscle. We then analyzed the time course of the
estrogen-responsiveness of these genes in several tissues, finding changes in expression patterns especially in skeletal muscle but not in the hypothalamus. Our results show that the
estrogen-responsive genes, which were demonstrated simply as either up- or down-regulated in their expression by
estrogen in a human cell line using
cDNA microarrays, exhibit tissue and temporal-specific expression patterns in adult female rats.