Effect of increased calcium concentration on in vitro growth of human colonic mucosal lines

The influences of different calcium concentrations in the culture medium on in vitro growth kinetics (generation time and saturation density) of established human colonic mucosal lines derived from subjects with and without familial adenomatosis of the colon and rectum were studied to test the hypothesis that hyperproliferation of colonic mucosal cells observed in some familial colon cancer can be reversed by increased extracellular calcium concentration. From the present studies, the genomic source of the adenomatous colonic lines appear to modify the effect of increased calcium on mucosal growth as demonstrated by differences in growth response in lines with and without the biomarker associated with genetic predisposition for some colon cancers, increased in vitro tetraploidy. Such observations suggested that other factors, including genomic differences, should be taken into consideration in the determination of the possible influences of calcium concentration on colonic mucosal proliferation.