Growth modulation by epidermal growth factor (EGF) in human colonic carcinoma cells: constitutive expression of the human EGF gene.

摘要: The functional role of epidermal growth factor (EGF) in epithelium-derived human colonic carcinoma cells was investigated by transfection with plasmid pUCDS3, which contained synthetic EGF encoding sequences, into two cell types dissimilar phenotypic properties: the moderately differentiated and factor-responsive Moser highly metastatic KM12SM cells. exhibited a proliferative response to treatment exogenous EGF, while did not. constitutive expression gene these resulted elevated mRNA, concurrent production secretion large amount downmodulation transforming factor-alpha (TGF-alpha) secretion. Growth stimulation down-modulation both high low affinity receptors were observed EGF-transfected clones. Results experiments using anti-EGF anti-EGF-receptor antibody block proliferation clones suggested that autocrine stimulatory mechanisms involving TGF-alpha operative By comparison, growth-inhibitory effect, no apparent receptor modulation, Both parental possessed fewer than cells, or not affect cells' properties. These results inhibition non-autocrine intracellular nature. Thus, phenotypically different, divergent altered characteristics.