Anti-oestrogens induce the secretion of active transforming growth factor beta from human fetal fibroblasts

Abstract

(Green & Leake, 1987). These cells were allowed to grow for 3 days, until approximately 50% confluent. The medium was then discarded and the cell monolayers washed twice with warm phosphate-buffered saline. The cells were then incubated with 50 ml of a defined medium consisting of phenol red-free MEM, supplemented with 2 mM L-glutamine, MEM vitamins, 5 yg ml-1 bovine insulin, 5 jig ml' human transferrin, 2 lag ml-' bovine fibronectin, 10 ng ml-' bovine epidermal growth factor, 1 nM sodium selenite and 0.

PCR display identifies tamoxifen induction of the novel angiogenic factor adrenomedullin by a non estrogenic mechanism in the human endometrium

“…Thus, tamoxifen was found to be a potent activator of ER mediated induction of promoters regulated by AP-1 sites in a cell type speci®c pattern; with agonism only occurring in cell lines of uterine but not of breast origin (Webb et al, 1995). Alternatively tamoxifen may act by an oestrogen independent mechanism as has been proposed for its stimulation of TGFb in vitro in human fetal ®broblasts and in vivo in human breast tissue stroma (Colletta et al, 1990;Butta et al, 1992).…”

The extracellular regulation of growth factor action.

“…LAP regulates TGF-,B activity in cell culture (Gentry and Nash, 1990) and in vivo (Wallick et al, 1990) and influences the distribution of TGF-,B in the organism, increasing the halflife of the growth factor 50-fold . Latent TGF-f circulates in plasma at concentrations well above those necessary for TGF-f to elicit biological activity (Danielpour et al, 1989 (Knabbe et al, 1987;Glick et al, 1989;Oreffo et al, 1989;Colletta et al, 1990;Twardzik et al, 1990;Flaumenhaft et al, unpublished data). Activation of latent TGF-#1 also occurs in homotypic cultures of erythroleukemia cell lines (Piao et al, 1990) (Jullien et al, 1989;Pfeilschifter et al, 1990).…”

Stromal influences on breast cancer cell growth

“…In addition it has been shown that a fibroblast-derived polypeptide from malignant breast tumours cause a significant increase of epithelial 17-beta-estradiol dehydrogenase activity, thereby increasing the local concentration of estradiol (Adams et al, 1988b). Moreover, exposure of human foetal fibroblasts to antioestrogens induces the secretion of active transforming growth factor-beta, despite the absence of oestrogen receptor within these cells (Colletta et al, 1990).…”