2P-41 PDF
Quantitative analyses of a serum carbohydrate tumor marker candidate, core 1 sialyl Lewis A, by SRM analyses
We have attempted to identify novel glycan tumor marker candidates. O-glycans were prepared from sera by hydrazine treatment followed by fluorescent labeling and their corresponding profiles were constructed. Serum O-glycan profiles from healthy controls and cancer patients were compared, and some tumor marker candidates could be detected. One such candidate had a sialyl Lea core 1 structure, and its concentration appeared to be weakly correlated with serum CA19-9 values. To quantify this target glycan in sera with high sensitivity and accuracy we established the SRM assay using stable isotope labeled standard. Serum levels of the target of 194 healthy controls, 146 gastric cancer patients, 101 colorectal cancer patients, and 65 pancreatic cancer patients were measured. These analyses revealed that i) this marker was distinct from CA19-9, ii) cut-off values can be set to 10PPM, iii) elevated levels of this glycan were found in sera of cancer patients, (stomach 15/146, colon 7/101, pancreas 33/65), and iv) this glycan may be valuable as a diagnostic adjunct for cancer.