The putative tumor suppressor deleted in malignant brain tumors 1 is an estrogen-regulated gene in rodent and primate endometrial epithelium.
Deleted in malignant brain tumors 1 (DMBT1) is a candidate suppressor of malignancies of the brain, lung, gut, and breast. We have been studying gene expression in the uterus in the presence of estrogens and their antagonists. Here, we show that DMBT1 RNA levels are robustly increased by estrogen treatment in the uteri of ovariectomized monkeys and rats. In monkeys, the progestin antagonist mifepristone inhibits estrogen-dependent uterine proliferation. As determined by a microarray experiment and quantitative analysis of RNA levels, mifepristone inhibited estrogenic induction of DMBT1. DMBT1 was not expressed in intact monkeys that were treated with a gonadotropin agonist to suppress steroidogenesis. An in vitro transfection study with human DMBT1 promoter constructs showed that an Alu site approximately 3000 nucleotides upstream of the gene mediates estrogenic regulation. Surprisingly, the estrogen antagonists tamoxifen, raloxifene, and ICI 182,780 also induced gene expression via this Alu site. Rodents represent a more convenient model system for studying uterine biology than monkeys. In rats, uterine DMBT1 RNA levels were dramatically up-regulated by estrogen. Consistent with the transfection study, tamoxifen and raloxifene increased DMBT1 RNA levels in vivo, but ICI 182,780 inhibited an estrogen-induced increase. Immunohistochemical studies showed that DMBT1 is specifically induced in glandular and luminal epithelia of the rat endometrium. Our experiments establish that DMBT1 is an estrogen-responsive gene with a possible role in endometrial proliferation or differentiation, and they have implications for the putative tumor suppressive and mucosal protective functions of DMBT1 in the uterus.
Tynan
Sharon
S
Reproductive Therapeutics, Johnson & Johnson Pharmaceutical Research and Development, L.L.C., Room B-115, 1000 US Route 202 South, P.O. Box 300, Raritan, New Jersey 08869, USA.
Pacia
Emmanuel
E
Haynes-Johnson
Donna
D
Lawrence
Danielle
D
D'Andrea
Michael R
MR
Guo
Jian-Zhong
JZ
Lundeen
Scott
S
Allan
George
G
D000373:Agglutinins / Q000502:physiology*; D020087:Alu Elements; D000818:Animals; D015152:Blotting, Northern; D002135:Calcium-Binding Proteins; D002454:Cell Differentiation; D002460:Cell Line; D004268:DNA-Binding Proteins; D004305:Dose-Response Relationship, Drug; D004717:Endometrium / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology; D004965:Estrogen Antagonists / Q000494:pharmacology; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D000077267:Fulvestrant; D005786:Gene Expression Regulation; D000882:Haplorhini; D006801:Humans; D007150:Immunohistochemistry; D008156:Luciferases / Q000378:metabolism; D009077:Mucins / Q000096:biosynthesis / Q000502:physiology*; D009092:Mucous Membrane / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D010957:Plasmids / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D020849:Raloxifene Hydrochloride / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011956:Receptors, Cell Surface / Q000502:physiology*; D013629:Tamoxifen / Q000494:pharmacology; D014162:Transfection; D025521:Tumor Suppressor Proteins; D015854:Up-Regulation; D014599:Uterus / Q000378:metabolism
D000373:Agglutinins; D002135:Calcium-Binding Proteins; C108174:DMBT1 protein, human; D004268:DNA-Binding Proteins; C114202:Dmbt1 protein, mouse; C498499:Dmbt1 protein, rat; D004965:Estrogen Antagonists; D004967:Estrogens; D009077:Mucins; D011956:Receptors, Cell Surface; D025521:Tumor Suppressor Proteins; D013629:Tamoxifen; D000077267:Fulvestrant; D020849:Raloxifene Hydrochloride; D004958:Estradiol; D012313:RNA; D008156:Luciferases