PATHOLOGY & ONCOLOGY RESEARCHVol. 11 No. 2, 2005

 Article

Influence of Sialic Acid Removal on MUC1 Antigenic Reactivity in Head and Neck Carcinoma

María V CROCE, Martín E RABASSA, Adrián PEREYRA, Amada SEGAL-EIRAS

Centro de Investigaciones Inmunológicas Básicas y Aplicadas (CINIBA), Facultad de Ciencias Médicas, UNLP, La Plata, Argentina

 

To investigate the influence of sialic acid removal on MUC1 peptidic and carbohydrate epitope reactivity in head and neck squamous cell carcinoma (HNSCC), tumor samples belonging to 24 HNSCC patients were studied by standard immunohistochemistry (IHC) with and without desialylation with 0.1 U/ml neuraminidase. From each tumor sample, subcellular fractions were obtained and analyzed by SDS-PAGE and Western blotting (WB). Three monoclonal antibodies (MAbs) were used: C595 MAb directed to MUC1 protein core, an anti-Tn hapten MAb, and an anti-sTn hapten MAb; a comparative analysis between desialylated and sialylated samples was performed. By IHC without neuraminidase treatment, 19 of 24 samples reacted with anti-MUC1 peptidic epitope, while Tn hapten was not detected and sTn was found in 1 of 24 cases. Desialylation increased either the number of reacting cells or the intensity of the reaction with C595 and anti-Tn MAbs, and some negative samples became positive. On the other hand, sTn expression decreased with desialylation. By WB, several bands from >200 to 25 kDa were found; desialylation increased high-molecular-weight bands, diminishing the detection of low-molecular-weight ones. The use of desialylation is a suitable treatment that contributes to the exposure of MUC1-associated epitopes, which may be related to the spreading of HNSCC. Pathology & Oncology Research, Vol 11, Nr 2, 74-81, 2005

Key words: head and neck carcinoma; MUC1; carbohydrate antigens; sialic acid


Received: Oct 29, 2004; accepted: Dec 10, 2004
Correspondence: Amada SEGAL-EIRAS, Centro de Investigaciones Inmunológicas Básicas y Aplicadas (CINIBA), Facultad de Ciencias Médicas, UNLP, Calle 60 y 120 La Plata , Argentina; Tel: 54 221 4870414, Fax: 54 221 4871481; E-mail: as-eiras @netverk.com.ar

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