Additionally, the p53 targets, HDM-2 and p21 (WAF1), were present in ulcerative colitis (UC) colon, but undetectable in normal colon, consistent with activated p53.
Increased lower-third crypt p21(WAF1/CIP1) staining was seen in 57% of AUC cases; decreased upper-third crypt p21(WAF1/CIP1) staining, in 23% of dysplasia cases; and absent or weak p21(WAF1/CIP1) staining, in 55% of UC-related CRCs.
Whereas mdm-2 and bcl-2 were only sporadically expressed, waf-1 was observed in most specimens, with a high prevalence in UC without carcinoma or dysplasia (11/15).
All of the indices in active UC were significantly higher than in either remitting UC cases or normal cases (mean mitotic index = 0.52, 0.28, and 0.15%, respectively; apoptotic index = 5.40, 2.91, and 1.30%, respectively; Ki-67 labeling index = 39.5, 28.3, and 26.8%, respectively; p21WAF1/CIP1 labeling index = 33.6, 20.0, and 19.0%, respectively; p53 labeling index = 0.66, 0.13, 0.13 per crypt, respectively).