GROWTH-FACTOR REQUIREMENTS OF HUMAN COLORECTAL TUMOR-CELLS - RELATIONS TO CELLULAR-DIFFERENTIATION

Human colorectal tumour lines that exhibit different degrees of differentiation were studied to define their growth requirements. The poorly differentiated cell lines SW620, SW480, SW48 and SW837 proliferated in Dulbecco's modified Eagle's medium without exogenously added growth factors. In contrast, the moderately differentiated cell lines SW1222, HT29, PC/JW and LS174T proliferated only in medium supplemented with growth factor. SW1222 and HT29 cells required transferrin for growth, which was improved by other growth-promoting factors including epidermal growth factor (SW1222) and sodium selenite (HT29). PC/JW and LS174T required both insulin and transferrin for optimal growth. The tumour cell lines could be passaged continuously in serum-free medium supplemented with growth factor and in some cases they grew better than in serum-supplemented medium. The serum-free growth conditions should prove useful for studies on differentiation in colorectal cell lines and their interactions with growth factors.