MUC1 tissue expression defined by MUC1 cytoplasmic tail detection in colorrectal cancer

CROCE MV; LACUNZA E; DEMICHELIS S; COLUSSI AG; SEGAL-EIRAS A

Córdoba

Congreso; VII Congreso Latinoamericano de Inmunología (ALAI); 2005

The aim of this study was to investigate the expression of MUC1 mucin by MUC1 cytoplasmic tail (MUC1-CT) in colorectal  carcinoma. A total of 98 colorectal  carcinoma, 14 benign colorectal colorectal  and 20 normal tissue  samples were assayed  by standard  immunohistochemistry  (IHC). Subcellular fractions were obtained and analyzed by SDS PAGE and WB. The antibodies used were anti-MUC1 CT: CT2 monoclonal antibody (MAb) and CT33 polyclonal antibody (Ab) and C595 MAb, recative with the extracellular  MUC1 protein core .Statisitical analysis employed was a nonparametric test (Principal Component Analyisis, PCA with Kendall correlation). Results: By IHC, with CT2  MAb, 53% (47/89) colorectal canrcinoma  samples showed positive reactivity whereas 86% (12/14) benign samples and 75% (15/20) normal tissue were positive. With CT33 Ab, the reaction observed was as follows: 48% (43/89) malignant samples, 64% (8/14) benign disease and 55% (11/20) normal tissue reacted positively. Employing C595 MAb, positive staining was detected in 53% (47%) colorrectal carcinoma samples, 21% (3/14) benign and 60% (12/20) normal samples. By WB with CT33 Ab, cytoplasmic subcellular fraction showed an intense band at approximately 30KDa. Conclusions: This study suggests that CT33 is as useful as CT2 in identified the MUC1 mucin cytoplasmic tail (MUC1 CT) in colorectal carcinoma.