Figure 2

Effects of DAPT on Notch signaling (Notch1, Hes1, and ATOH1), Cdx2, and MUC2 expressions in OE33, OE19, and Het-1A cells. Hes1 mRNA levels were downregulated, whereas ATOH1, Cdx2, and MUC2 mRNA levels were upregulated by the γ-secretase inhibitor DAPT in concentration- and time-dependent manners. (a) OE33, (b) OE19, and (c) Het-1A cells were exposed to DAPT for 12, 24, and 48 h at concentrations of 0, 5, 10, and 20 μM. Expressions of the indicated genes were quantitated by real-time PCR. The results are expressed as the mean±s.e.m. of four experiments. Data were normalized to the expression level of GAPDH. A value of 1 for this ratio was assigned arbitrarily to the data obtained from the control. ^*P<0.05, statistically significant difference vs control. ^**P<0.01, statistically significant difference vs control. NS indicates that the comparison was not significant (n=4 for each group). Effects of DAPT on cleaved Notch1, Hes1, ATOH1, Cdx2, and MUC2 protein expressions in (d) OE33 and (e) OE19 cells. Cells were stimulated with various concentration of DAPT or the vehicle alone for 24 h, and then proteins were extracted and subjected to western blot analysis for cleaved Notch1, Hes1, ATOH1, Cdx2, MUC2, and β-actin. Blots shown are representative of three separate experiments.