Immunodiagnostic potential of mucin (MUC2) and Thomsen-Friedenreich (TF) antigens in Egyptian patients with colorectal cancer.

OBJECTIVE Colorectal cancer (CRC) is more common in developed countries and is the third most common cancer among both men and women. CRC provides an attractive model of tumour biology with normal mucosa to adenoma to carcinoma sequence. The TF-antigen (Thomsen-Friedenreich) can be identified by galactose oxidase-Schiff's (GOS) reaction either on tissues or on rectal mucus samples from patients with CRC. TF antigen is expressed in the neoplastic mucosa and not expressed in colonic mucosa of normal subjects. Apomucins play important role in cell signalling and their specific pattern of expression during the different steps of tumor progression toward adenocarcinoma suggests that they play significant roles in tumorigenesis. The family of secreted mucins including MUC2 is contributing in mucus formation to protect underlying epithelia against diverse injuries. The current study was investigated the expression of MUC2 and TF antigens in patients with adenoma and CRC. MATERIALS AND METHODS MUC2 and TF antigen expressions were detected immunohistochemically in CRC biopsies using specific monoclonal antibodies. Moreover, the TF antigen was invesigated using GOS reaction. RESULTS The results showed that in normal colonic specimens, MUC2 expression was detected in 20%, while TF antigen was completely negative in 100% of samples as detected by GOS and immunohistochemistry using anti-TF monoclone. Expressions of MUC2, and TF antigen as detected by GOS and anti-TF monoclone were positive in 96%, 80%, and 60% respectively in cases with adenoma. On the other hand, in cases with adenocarcinoma, the expression of MUC2 was seen in 92% of cases, while TF antigen was observed in 84% and 60% of cases as detected by GOS and immunohistochemically respectively. CONCLUSIONS Thus, it is concluded that the expression of MUC2 and TF antigens are altered during CRC carcinogenesis. Furthermore, MUC2 and TF antigens may have a diagnostic and or prognostic potential in CRC.