MEDI 51 |
| There exist numerous carbohydrate cancer biomarkers such as T-antigen, Tn, and lewis antigens. Just like any other cancer biomarkers, their expression levels vary from one sample to another, thus making individual tumor antigens not excellent diagnostic agents. One way to tackle this problem is by screening for multiple markers simultaneously in samples and evaluating their overall expression. The innovation of microarray technology has allowed high throughput screening of large number of samples in small quantities, allowing simultaneous detection. Unlike their DNA and protein counterparts, carbohydrate microarrays have been hard to develop due to various challenges. Over the past year, we have developed a fully functional carbohydrate array. As initial projects, we have analyzed the specificities of commercially available 29 anti-carbohydrate antibodies and 23 lectins through titer measurements. As expected, all the lectins were nonspecific, but to our surprise we have found out that more than half the antibodies that are sold as specific receptors have specificity problems. Based on these results, the antibody and lectin that were identified as most specific for the Tn antigen has been used to stain various tumor tissue samples for accurate expression information. It was found that unlike popular beliefs only certain types of cancers such as colon and stomach tumors over express Tn. Identifying the right tumor types has tremendous implication in Tn based vaccine development. Along with other applications, we are attempting to adapt the array as a direct diagnostic tool. Since most tumor antigens elicit autoantibody production, numerous serum samples from normal and cancer patients can be screened on the carbohydrate microarry. The antibody expression will be proportional to the carbohydrate antigen expression. The overall expression profile of the numerous antigens from the microarray can then lead us to characterize the type and stage of various tumors. |
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General Poster Session
7:00 PM-9:00 PM, Sunday, 10 September 2006 Moscone Center -- Hall D, Poster
Sci-Mix
Division of Medicinal Chemistry |