Figure 4

Expression of p21 ^WAF1/CIP1 in HT-29 Cells is regulated by EGFR trans-activation through the EP4 receptor. (4a) Expression of p21 by qRT-PCR in HT-29 cells following treatment with EP4A (L-161,982) 10 μM for 4 hours. Values shown are the Mean +/- SEM for n = 3. p values are for paired students t-test. (4b) Expression of p21 by qRT-PCR in HT-29 cells showing a comparison of the effects of EP4A (10 μM), a EGFR tyrosine kinase inhibitor (PD153025, 1 μM) and the PI3 Kinase inhibitor (Wortmannin, 1 μM). Values shown are the Mean +/- SEM (n = 3). One way ANOVA (overall) p = 0.0001, p values shown are for Bonferroni multiple comparisons test between selected groups.