The effect of interferon treatment on 14 human colorectal cancer cell lines: growth and carcinoembryonic antigen secretion in vitro.

The effect of interferons (IFNs) on growth inhibition and carcinoembryonic antigen (CEA) secretion by 14 established human colorectal carcinoma cell lines was studied in vitro. The cell lines were characterized by morphologic differentiation, level of CEA production, and rate of growth. All cell lines were treated in vitro with recombinant human IFN (alpha, beta, and gamma) and the effect of treatment on growth rate and CEA secretion determined. Each cell line exhibited an individual pattern of growth inhibition that was independent of degree of differentiation, level of CEA production, and rate of growth. IFN-beta treatment did not increase CEA secretion in any of the cell lines studied. IFN-alpha and IFN-gamma resulted in increased CEA production (2- to 81-fold increase) primarily in the moderately to well-differentiated cell lines. IFN-gamma was a more potent inducer of enhanced CEA secretion than IFN-alpha. The more poorly differentiated cell lines did not produce CEA and could not be induced to do so by any of the IFNs.