Combination of culture on collagen gels and glucose starvation for cloning human colon cancer cells. Obtention of clones exhibiting different patterns of enterocytic differentiation.

Glucose starvation has been widely used to select differentiated subpopulations from the heterogenous human colon cancer cell line HT29. We observed that the important cell loss elicited by culturing these cells in glucose-free medium could be limited when type I collagen gel was used as substratum instead of conventional plastic support. We took advantage of this property to develop a new protocol, which combined glucose starvation and culture on collagen gels, for cloning HT29 cells. Using this procedure we have isolated four clones that were characterized on the basis of morphological (optical and transmission electron microscopy), electrophysiological (determination of transepithelial electrical parameters) and biochemical (detection of villin, sucrase-isomaltase and carcinoembryonic antigen) criteria. These four clones expressed different patterns of enterocytic differentiation regarding to these criteria. These results confirmed the heterogeneity of the HT29 cell line. One of these clones, HT29-A7, which displayed numerous intercellular cysts that disappeared at confluency, appears as a complementary model in the study of epithelial biogenesis.