Regulation of expression of CFTR in human intestinal epithelial cells.

As a first step in our efforts to delineate the role of CFTR in cellular phenotypes we have studied its expression in cultured human intestinal epithelial cells. In particular we have examined the effect of cellular differentiation on CFTR gene expression. CFTR mRNA was measured by quantitative densitometry of Northern blots and normalized to the amounts of pyruvate dehydrogenase message. We have found that in T84 cells the levels of CFTR mRNA do not change as the cells grow to confluence. In contrast, levels of CFTR mRNA increase by a factor of 10-20 as Caco2 cells grow after subculture. This change in the levels of CFTR mRNA is correlated with the morphological differentiation that occurs in Caco2 cells during culture. The potential significance of this observation is discussed.