Mucin-related antigens

CA 15-3 and CA 19-9 are variably expressed in thyroid follicular tumors. Both follicular and papillary carcinomas reveal CA 15-3 positivity in 100% of cases, whereas CA 19-9 is present in 70% of papillary tumors but in no follicular carcinomas.CA 125 immunoreactivity has been reported in approximately 40% of papillary carcinomas.The distribution of mucin-related antigens (MUC) has also been analyzed in thyroid tumors.These studies have demonstrated that MUCl plays a key role in the glycosylation of well-differentiated thyroid carcinomas. However, there are no consistent differences between papillary and follicular carcinomas with respect to the expression of mucins. 

Scheme 5 The "cassette" approach for glycopeptide synthesis and its application for the preparation of mucin-related antigen clusters.

Kuduk, S., Schwarz, J., Chen, X.-T., et al. (1998) Synthetic and immunological studies on clustered modes of mucin-related Tn and TF G-linked antigens The preparation of a glycopeptide-based vaccine for clinical trials against prostate cancer. /. Am. Chem. Soc. 120,12474-12485. 

Mukaiyama, T, Ikegai, K, Jona, H, Hashiyata, T, Takeuchi, K, A convergent total synthesis of the mucin related Fla antigen by one-pot sequential stereoselective glycosylation, Chem. Lett., 840-841, 2001. 

Marcaurelle, L. A., Shin, Y., Goon, S., and Bertozzi, C. R. (2001) Synthesis of oxime-linked mucin mimics containing the tumor-related T(N) and sialyl T(N) antigens. Org. Lett. 3, 3691-3694. 

Carbohydrate-related tumor markers either are (1) antigens on the tumor cell surface or (2) secreted by the tumor cells. Monoclonal antibodies have been developed against these antigens. These markers have been found to be clinically useful as tumor markers and tend to be more specific than naturally secreted markers, such as enzymes and hormones. Biochemically, they are high molecular weight mucins (Table 23-10) or blood group antigens (Table 23-11). 

Pleurodeles waltl and Ambystoma mexicanum (axolotl), bred in many laboratories, were chosen because of the abundance of mucins which surround their eggs. The first analyses led to the isolation of Lewis and Lewis antigenic determinants, which are known to be related to human tumor-associated antigens. For these reasons, the jelly coats of amphibian eggs could represent a valuable model to examine 0-linked carbohydrate structures during evolution, associated with a possible function involving specific markers for the fertilization process. 

Gulmann C, Counihan I, Grace A, et al. Cytokeratin 7/20 and mucin expression patterns in oesophageal, cardia and distal gastric adenocarcinomas. Histopathology. 2003 43 453-461. Sheahan K, O Brien MJ, Burke B, et al. Differential reactivities of carcinoembryonic antigen (CEA) and CEA-related monoclonal and polyclonal antibodies in common epithelial malignancies. Am J Clin Pathol. 1990 94 157-164. 

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