Genetically tagged putative differentiation intermediates derived from undifferentiated HT29 human colon carcinoma cells.

The HT29 colonic carcinoma cell line has proven to be a very practical tool for modelling aspects of colonic cell differentiation and toxification by chemotherapeutic agents. As an approach to subclone and clarify molecular events involved in sublineage maturation, non-differentiated HT29 cells were electroporated with a dominant marker gene (NeoR) to convey aminoglycoside resistance (G418R). Transfectants surviving passage in glucose-G418 medium were >200 times the abundance of transient G418R cells of controls. Genomic analysis showed that each clonal type was unique in NeoR integration pattern while mitochondrial DNA copy was relatively unchanged. All of the randomly generated NeoR clones resembled the parental phenotype, but some over-produced the mucin, secretory cell type or the cell death phenotype after culturing in 2 mM sodium butyrate medium. Re-exposure to glucose medium restored the parental-like phenotype.