| Abstract: |
Novel or modified serum-free media were developed for the anchorage-dependent growth of nontransformed murine mammary epithelial cells (MMEC) and Balb/MK murine keratinocytes respectively. Growth rates for both cell lines were similar in serum-containing and serum-free media. The serum-free media were used to evaluate potential mechanisms of epithelial cell growth regulation by type 1 transforming growth factor β(TGF-β1). The growth of MMEC and Balb/ MK cells was reversibly inhibited 40-65% in a time- and dose-dependent fashion by TGF-β1 under both serum-containing and serum-free conditions. Constitutive over-expression of a stranfected c-myc oncogene inMMEC did not result in loss of sensitivity to growth inhibition by TGF-β1. In addition, Balb/MK and MMEC growth inhibition by TGF-β1 was not potentiated by polynsaturated fatty acids or reversed by vitamin E. Expgenous type V collagen was able to mimic the inhibitory effects of TGF-β1 on the serum-free growth of Balb/MK and MMEC. In contrast, collagen type I and IV, fibronectin and laminin did not inhibit the growth of these cells. The type V collagen used was not contaminated with TGF-β, and subsaturating, but not saturating concentrations of type V collagen and TGF-β1 were additive with respect to Balb/MK and MMEC growth inhibition. These results demonstrate that nontransformed epithelial cell growth inhibition by TGF-β1 is mediated by mechanisms distinct from those observed with certain carcinoma and melanoma cells. Our results also suggest the possible involvement of type V collagen in Balb/MK and MMEC growth inhibition by TGF-β1. © 1990 Tissue Culture Association. |
| Keywords: |
nonhuman; animal cell; mouse; animal; mice; cell division; gene expression; cell growth; transforming growth factor beta; culture medium; tumor cells, cultured; keratinocyte; animalia; blood; collagen; murinae; breast epithelium; epithelium cell; epithelium; oncogene c myc; proto-oncogene proteins c-myc; keratinocytes; collagen type 5; mammary neoplasms, experimental; tgf-β1; extracellular matrix proteins; mammary epithelial cells; polyunsaturated fatty acid; fatty acids, unsaturated; female; priority journal; article; support, u.s. gov't, p.h.s.; type v collagen; mammae; defined media
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