β1,3-Galactosyltransferases-4/5 are novel tumor markers for gynecological cancers

Background/Aims: While the CA 125 and SCC antigens are used as tumor markers for ovarian cancer and uterine cervical cancer, respectively, an effective marker for uterine corpus cancer has not been identified. We asked whether β1,3-galactosyltransferase-4 and/or 5 (β3Gal-T4/T5) could serve as novel tumor markers for detecting gynecological carcinomas, especially those of the uterine corpus. Methods: We obtained a monoclonal antibody and a polyclonal antiserum against β3Gal-T5 and constructed a sandwich ELISA method. Western blot analysis and immunoprecipitation revealed that this ELISA recognizes both β3Gal-T4 and β3Gal-T5. Results: We found β3Gal-T4 and T5 enzymatic activity in ovarian cancer tissues, indicating that these enzymes are expressed at least in ovarian cancer. The cutoff value was determined by ROC analysis to be 5.4 ng/ml in the sera. The β3Gal-T4/T5- positive rates for the sera from ovarian cancer and uterine cervical cancer patients were comparable with the CA 125- and SCC antigen-positive rates for these cancers, respectively. Significantly, the β3Gal-T4/T5-positive rate was higher for uterine corpus cancer (64%) than the CA 125 (37%)- and CA 19-9 (24%)-positive rates. The stage I uterine corpus cancers had particularly high β3Gal-T4/T5-positive rates (57%). Conclusion: β3Gal-T4/T5 is a novel tumor marker for uterine corpus cancer and other gynecological cancers.