EP300 and malignant colon neoplasm: To verify the role of UA in regulating the p300 signaling in colon cancer cells, we pretreated with roscovitine, an inhibitor of p300 (Fig. 6C), or transfected with a p300-expressing vector in SW480 cells (Fig. 6D), and the effects of UA on roscovitine or p300-mediated cell proliferation were analyzed.