Wnt3a suppresses c-myc expression in p300 (+/−) 3T3 cells, whereas Wnt5a induces c-myc expression in CBP (+/−) cells. In CBP (+/−) cells in which there is a significantly increased ratio of p300 to CBP, treatment with Wnt5a or Wnt3a+Wnt5a conditioned media (CM) led to increased c-myc mRNA expression, which was not observed with Wnt3a alone, as assessed by real-time PCR. In contrast, Wnt3a dramatically reduced c-myc message in p300 (+/−) cells, whereas Wnt5a and Wnt3a+Wnt5a treatment did not greatly change c-myc expression compared to control media-treated cells. n ≥ 2, *p < 0.05, **p < 0.01.