Comparison of the Expression of P53, P21, P16, E-Cadherin and |β-Catenin Proteins in Colorectal Adenocarcinoma and the Nontumoral Immunohistochemistry and Tissue Array Techniques

Colorectal adenocarcinoma is one of the most prevalent and treatable malignancies of the gastrointestinal tract. Pattern of expression of the P53, P21, P16, E-cadherin and |β|-Catenin proteins are shown to be related to the prognosis of this malignancy. We aimed to compare the pattern of expression of these proteins in tumoral and nontumoral mucosal cells of cancer and on-cancer patients in relation to the histological prognostic factors.

2.5 millimeter cylindrical cores were punched out from selected tumoral and non-tumoral areas of the paraffin blocks of 58 colorectal cancer patients and colonic mucosa of 50 colons removed for other reasons. The samples were arrayed in paraffin blocks in groups of 30. Histological sections were evaluated for the expression of the target proteins by immunohistochemical techniques.

P53 was expressed more in tumoral than non-tumoral mucosal cells of the cancer and non-cancer patients (p‹0.001) and was related to vascular invasion (p=0.017). Expression of E-Cadherin was related to poor differentiation (p=0.023) and inversely to vascular invasion (p=0.025). Membranous expression of β-Catenin was inversely related to vascular invasion (p=0.049). Cytoplasmic and nuclear expression of this protein was more in tumor cells (p‹0.001). Also, the cytoplasmic expression of β-Catenin was inversely related to the stage (p=0.013) whereas nuclear expression was related to poor differentiation. (p=0.012). The pattern of expression of P21 and P16 were not found to have any relation with the histological prognostic factors.

It seems that the determination of the pattern of expression of P53, E-Cadherin and β-Catenin in colorectal adenocarcinoma, which is applicable on colonoscopic biopsies, could predict the biological aggressiveness of the tumor which might have therapeutic implications.