Reengineering cell-surface glycans for anti-cancer applications.

Abstract

The expressions of sialic acids are found to be elevated in cancer cells. Research on such expression is of great interest as these glycoconjugates are potential cancer biomarkers. Scientists have developed various chemical techniques like the Staudinger ligation and cycloaddition reaction to label and image glycans. However, the solubility and synthesis of chemicals involved in these two steps labeling methods are an issue. To solve these, we tried to develop a technique that makes use of fluorescence produced by dansyl to label glycans. The dansyl group was attached to the sialic acid biosynthetic precursor, N-acetylmannosamine (ManNAc). A charged group was also introduced to improve the overall solubility of the final compound, N,N-dimethylacetylAc3ManNDansyl, which can be easily synthesized in five simple steps. This was supposedly a more efficient labeling method as only one step is required. However, results obtained were not ideal as fluorescence displayed by control cells and cells incubated with N,N-dimethylacetylAc3ManNDansyl were similar. Due to time limitation, the study was halted at this stage and no conclusion could be drawn. Future studies are recommended to determine if this method is successful in labeling and imaging sialic acids.