HISTOLOGY AND HISTOPATHOLOGY

Cellular and Molecular Biology

 

MUC1 cytoplasmic tail detection using CT33 polyclonal and CT2 monoclonal antibodies in breast and colorectal tissue

M.V. Croce1, M. Isla-Larrain1, F. Remes-Lenicov1, A.G. Colussi1, E. Lacunza1, K.C. Kim2, S.J. Gendler3 and A. Segal-Eiras1

1Centre of Basic and Applied Immunological Research (CINIBA), Faculty of Medical Sciences, UNLP, La Plata, Argentina, 2University of Maryland, Baltimore, Maryland, USA and 3Department of Biochemistry/Molecular Biology, Mayo Clinic College of Medicine, Scottsdale, USA.

Offprint requests to: Prof. Amada Segal-Eiras, CINIBA, Facultad de Ciencias Médicas, UNLP Calle 60 y 120, La Plata, Argentina. e-mail: as-eiras@netverk.com.ar


Summary. The immunohistochemical detection (IHC) of MUC1-CT employing a polyclonal antibody (CT33) in relation to CT2 monoclonal antibody (MAb) was analyzed. Western blot (WB) was used to determine the molecular mass of CT. Materials and methods: we studied 163 breast and 89 colorectal cancer specimens, 10 breast and 14 colorectal benign conditions, and 12 breast and 20 colorectal normal samples. From each tumor sample, subcellular fractions were obtained and analyzed by SDS-PAGE and WB. A nonparametric statistical analysis was employed; data were standardized and a Kendall-Tau correlation was applied. Results: by IHC, 146/163 (90%) and 151/163 (93%) of breast cancer were positive with CT33 and CT2, respectively; a statistically significant correlation was obtained (t=0.5199). Seven out of ten (70%) benign breast specimens were positive with CT33 while all samples stained with CT2; in normal breast sample tissues, all were positive with both Abs. In colorectal cancer samples, both antibodies stained 47/89 (53%) samples; CT2 reacted in 13/14 (93%) of benign samples while CT33 showed a positive reaction in 9/14 (64%) of benign specimens. In normal samples, CT2 showed staining in 17/20 (85%) of samples and CT33 was reactive in 12/20 (60%). By WB, in breast and colorectal cancer samples, similar results were obtained with both antibodies: a main band at about 30kDa which represents the smaller subunit.
Conclusion: CT33 polyclonal antibody has demonstrated its efficacy to detect MUC1 in breast and colorectal cancer tissues with similar reactivity to CT2. It is worthwhile to affirm that CT33 is a good indicator of MUC1 expression. Histol Histopathol 21, 849-855 (2006)

Key words: MUC1 cytoplasmic tail, Breast cancer, CT33 polyclonal antibody, CT2 monoclonal antibody

DOI: 10.14670/HH-21.849