FIGURE 4.

Paneth cell differentiation response of Caco2 cells to FGF requires basolateral stimulation. Caco2 cells grown on semipermeable membranes were given FGF9 (50 ng/ml) daily on either the apical or the basolateral surface. Cells were harvested at 3 days postconfluence, and total RNA was extracted. HD5 (A) and HD6 (B) mRNA levels were determined by quantitative real-time PCR and expressed relative to 18 S rRNA. Vehicle represents cells receiving only growth medium. Values are the mean ± S.D. (error bars) of n = 3. N.S., not significant.