Relationship of angiogenesis and p53 protein expression in colorectal carcinomas

Recently, new functions have been attributed to the p53 protein, particularly a prominent role in the regulation of angiogenesis. Tumours expressing mutant forms of p53 protein may be associated with increased angiogenesis. The aim of this study is to investigate the relationship between p53 protein expression and the quantitative expression of tumour angiogenesis in colorectal carcinomas.

Sections from paraffin-embedded blocks from 46 patients with primary colorectal carcinomas that had been completely removed were analysed. p53 protein expression and all vascular structures were evaluated by immunohistochemistry. The vessel parameters of angiogenesis including vascular surface density (VSD), number of vessels per mm2 (NVES) and number of vessels in unit area (n) were assessed by morphometry. Mann-Whitney U-test was used for comparing the extent of neovascularization in p53-positive and -negative cases.

Twenty-four (52%) cases were p53+ and 22 (48%) were p53-. Mean VSD, NVES and n values for p53 protein-positive and -negative groups were as follows: VSD 96.7 +/- 65.4/mm vs 79.6 +/- 45.24/mm; NVES 104.8 +/- 97.5/mm2 vs 62.2 +/- 44.3/mm2; n 79.7 +/- 74.2 vs 52 +/- 35.7, respectively. There was no association between the angiogenesis parameters and p53-positive and -negative cases, when VSD (P=0.226) or n (P=0.176) were considered, but a statistically significant difference was obtained for NVES values (P=0.035).

The authors concluded that tumoural angiogenesis assayed by morphometric investigation in colorectal carcinomas might be related to p53 protein expression when NVES is considered. This finding supports the possible role of p53 protein in increased angiogenesis in colorectal tumours.