In situ hybridization for creatine kinase-B messenger RNA in rat uterus and brain.

Creatine kinase-B (CKB) is present in both uterus and brain, and in uterus its synthesis (protein and mRNA) is regulated by estrogen. In the present study we have used in situ hybridization to detect CKB mRNA in uterus and brain, and to determine whether there is cell type specific induction of CKB by estrogen in these tissues. Tissue was taken from ovariectomized (ovx) rats that had been injected with either estrogen (17 beta-estradiol-3-benzoate and/or 17 beta-estradiol) or vehicle alone, 2, 8, 24 and 72 h previously.

Estrogen control of uterine tissue factor messenger ribonucleic acid levels.

One of the early responses of the immature rat uterus to stimulation by estradiol (E2) is an increase in the specific activity and synthesis of a discrete set of proteins including tissue factor (TF). Increases in TF are associated with stimulation of cell growth in mouse and human fibroblasts and endothelial cells. The increase in TF activity following E2 stimulation of the uterus is due to an increase in TF messenger RNA (mRNA).

Delineation of sites mediating estrogen regulation of the rat creatine kinase B gene.

We have previously confirmed the estrogen-induced protein of rat uterus to be creatine kinase B (CKB), and demonstrated a 1.7-kilobase pair fragment encompassing the promoter and adjoining 5'-flank to be capable of conferring estrogen responsiveness in HeLa cells. In this study we find an element at -550, aGGTCAgaaCACCCt, with limited similarity to the estrogen response element consensus, to be involved in conferring estrogen responsiveness on the CKB promoter.

Estrogen-stimulation of postconfluent cell accumulation and foci formation of human MCF-7 breast cancer cells.

Foci, nodules of cellular overgrowth, that appear after confluence are an in vitro characteristic of malignant transformation. A well-studied in vitro model of estrogen-dependent tumors is the MCF-7 cell line, derived from a pleural metastasis of a human breast adenocarcinoma. We report that cultivation of MCF-7 cells, using routine methods, results in extensive estrogen-stimulated postconfluent cell accumulation characterized by discrete three-dimensional arrays.

2,3,7,8-Tetrachlorodibenzo-p-dioxin causes an extensive alteration of 17 beta-estradiol metabolism in MCF-7 breast tumor cells.

MCF-7 breast tumor cells form multicellular foci in vitro when supplemented with 17 beta-estradiol (E2). In the presence of E2 and the aryl hydrocarbon-receptor agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), MCF-7 cells grow to confluence but do not form foci. To investigate the role of E2 metabolism in this antiestrogenic effect of TCDD, analyses were performed by capillary GC/MS.