epidermal-growth-factor and Adenofibroma

Human breast epithelial cells isolated from normal breast tissues of premenopausal women demonstrated direct evidence of a proliferative effect by linoleate (18:2 omega 6) or prostaglandin E2 (PGE2) in the presence of insulin and epidermal growth factor in serum-free cultures within a collagen gel matrix. Neither epidermal growth factor nor 18:2 omega 6 by itself was capable of stimulating growth but together they stimulated proliferation synergistically. Epithelial cells isolated from fibroadenomas on the other hand failed to exhibit any growth stimulation due to 18:2 omega 6 or PGE2. The linoleate-stimulated growth in normal breast epithelial cells was inhibited by indomethacin, a cyclooxygenase inhibitor, which however could be reversed by PGE2. The proliferative response of normal breast epithelial cells to 18:2 omega 6 was accompanied by a greater conversion of [14C]18:2 omega 6 to arachidonic acid and [14C]20:4 omega 6 to prostaglandins than that seen in epithelial cells from fibroadenomas. The turnover of [14C]18:2 omega 6 in the phospholipids of normal cells was higher than in fibroadenomas indicating a possible role of phospholipids in mediating the 18:2 omega 6 effect in normal cells. Both normal and fibroadenoma cells can proliferate in response to cholera toxin and glucocorticoids when supplemented to the insulin- and epidermal growth factor-containing medium. From the results it appears that, unlike normal cells, fibroadenoma cells may have a specific defect in the PGE2-responsive cyclic AMP-generating mechanism whereas cholera toxin-induced mechanism is operative in both types of cells.

Topics: Adenofibroma; Breast; Breast Neoplasms; Cell Division; Cells, Cultured; Cholera Toxin; Epidermal Growth Factor; Epithelial Cells; Epithelium; Female; Humans; Hydrocortisone; Insulin; Linoleic Acid; Linoleic Acids; Tumor Cells, Cultured

Human breast epithelial cells derived from various sources (fibroadenoma, reduction mammoplasty, and mastectomy tissues from premenopausal patients) have been cultured in collagen gel matrix using serum-free medium. Response to various additives has been analyzed for growth-promoting effect when added to a basal medium containing insulin, cholera toxin, and BSA. A consistent observation has been the effect of EGF and cortisol in growth stimulation of human breast epithelial cells, while separately, each additive elicited only a small response. Under this condition, employing EGF and cortisol combinations, these cells gave rise to organized colonies consisting of clusters of cells, usually spherical, without any duct-like extensions. Ultrastructural and immunocytochemical studies, using a panel of monoclonal and polyclonal antibodies, have shown that cell types and features that can be identified in the original breast tissue can also be delineated in the progeny populations. The topographical feature, consisting of lumina surrounded by a single inner layer of epithelial cells and an outer layer of basal/myoepithelial cells, can be re-created in the collagen gel system starting from small clumps of cells.

Topics: Adenofibroma; Breast; Breast Neoplasms; Cell Division; Culture Media; Epidermal Growth Factor; Epithelial Cells; Epithelium; Growth Substances; Hormones; Humans; Hydrocortisone; Microscopy, Electron