High expression of uridine diphosphate-galactose: Lc₃Cer β1-3 galactosyltransferase in human uterine endometrial cancer-derived cells as measured by enzyme-linked immunosorbent assay and thin-layer chromatography-immunostaining

We have developed a new procedure for the selective determination of β1-3 and β1-4 galactosyltransferases with Lc₃Cer as the substrate and the microsomes of fetal and adult porcine livers as the enzyme sources. This method was based on the detection of such products as Lc₄Cer for β1-3 galactosyltransferase (β1-3GT) and nLc₄Cer for β1-4 galactosyltransferase (β1-4GT), with monoclonal anti-Lc₄Cer and anti-nLc₄Cer antibodies, respectively. This method thus enabled us to differentiate the activity of β1-BGT from that of β1-4GT with a high degree of sensitivity. The method was then used to determine the activities of both enzymes in human gynecological carcinoma-derived cells. Four of the five cell lines derived from uterine endometrial cancer expressed significantly high levels of specific activity of β1-3GT among the cell lines examined, while their β1-4GT activities were less than 20% of that for β1-3GT in the endometrial carcinoma-derived cells. On the other hand, a higher specific activity of β1-4GT than that of β1-3GT was detected in the cell lines derived from uterine cervical and ovarian cancers. These findings were thus found to correlate closely with the rate of expression of Lc₄Cer- and nLc₄Cer-based carbohydrate chains in the cell lines based on the results staining.