Tumor cells as the origin of elevated serum α1,3fucosyltransferase in association with malignancy

We have previously reported that the elevated activities of serum α1,3fucosyltransferase reverted to normal levels after curative removal of the tumors. To determine the origin of elevated serum α1,3fucosyltransferase, blood samples were obtained from both the drainage vein and the artery in patients with different stages of colorectal cancer at surgery. The enzyme levels in all samples from the drainage vein were found to be higher than the levels in the artery that fed the tumor. Hence, the origin of elevated α1,3fucosyltransferase in serum was thought to be the tumor rather than the liver that is the normal source of serum α1,3fucosyltransferase. When serum samples not only from colorectal cancer patients but also from patients with gastric, liver, lung, pancreas, bladder and esophagus cancer were treated with anti-FUTVI antibody, the measured activities of α1,3fucosyltransferase were markedly reduced. Further, secretion of α1,3fucosyltransferase from human colorectal carcinoma cells was also detected in the culture medium by Western immuno-blot analysis with anti-FUTVI antibody.