Demonstration of endogenous sialyltransferase on the surface of ehrlich tumour ascites cells

Serum sialyltransferase and fucosyltransferase activities in patients with multiple myeloma

A significant elevation of serum sialyltransferase and fucosyltransferase mean activities was observed in 19 untreated patients with multiple myeloma. However, sialyltransferase mean activity was significantly lower in 13 other patients treated for 1-30 months with alkylating drugs and prednisolone. Such a definite decrease in serum enzyme activity on treatment was not recorded for fucosyltransferase. Instead, this activity was significantly increased in treated patients as compared to controls. The presenting clinical features of the 32 patients with multiple myeloma were the basis for a clinical staging system with regard to myeloma cell burden according to established criteria. In untreated patients (as opposed to treated ones), a significantly higher serum sialyltransferase (but not fucosyltransferase) activity was obtained among those 11 belonging to stage III than among the other eight with stages I and II, suggesting a link between tumour burden and enzyme activity. This assumption was further strengthened in those six patients followed lengthwise with regard to serum sialyltransferase activity. Concomitantly with objective evidence of change in tumour burden they showed corresponding alterations in sialyltransferase activity. The determination of sialyltransferase and fucosyltransferase activity in serum may be an additional contribution to refine initial assessment and follow-up of individual patients with multiple myeloma.

Serum sialyltransferase and fucosyltransferase activities in patients with bronchial carcinoma

Serum sialyltransferases and fucosyltransferases measured by an affinity adsorbent technique were studied in 27 exactly defined patients with malignant pulmonary diseases. Fourteen patients with benign pulmonary diseases and 56 with benign surgical diseases were used as controls. Enzyme activities were expressed as amounts of labeled precursor molecules incorporated into endogenous acceptors in counts per minute (cpm). The mean sialyltransferase activity was 583 cpm in bronchial carcinoma, 485 cpm in benign pulmonary disease and 428 cpm in benign surgical disease. The only statistically significant difference was between bronchial carcinoma and benign surgical disease. The mean fucosyltransferase activity was 813 cpm in bronchial carcinoma, 436 cpm in benign pulmonary disease and 255 cpm in benign surgical disease. All the differences were statistically significant. There were no statistically significant differences between the WHO histologic bronchial carcinoma groups. The correlation between sialyltransferase and fucosyltransferase activity in bronchial carcinoma was statistically significant (r = 0.59). In squamous cell carcinoma (N = 6), it was strongly significant (r = 0.96) and there was a significant correlation also in small cell carcinoma (N = 10; r = 0.79) but not in adenocarcinoma (N = 9; r = 0.30) and benign pulmonary disease (N = 14; r = 0.44). It is suggested that serum sialyltransferases and fucosyl transferases would not be decisive for diagnosis when used alone in bronchial carcinoma, but could be included in a screening test battery.

The use of con A Sepharose as an affinity adsorbent in a simple assay of serum sialyl and fucosyltransferase and its application in tumour diagnosis

A considerably simplified assay for recording sialyl- and fucosyltransferase in human serum is presented. Serum samples incubated with labeled nucleotide-sugar and glycosylated endogenous acceptor molecules were adsorbed to Con A Sepharose and quantitated by scintillation counting. The results correlated with those of a much more time consuming acid precipition method, and displayed a higher diagnostic sensitivity due to the improved specificity of the method and the combined recording of the two activities. A correlation between serum sialyl- and fucosyltransferase activities as well as quantitative agreement between the amount of incorporated sialic acid and fucose indicated that rhe endogenous acceptor molecules were rate-limiting for transfer and may themselves have diagnostic potential.

[Sialyltransferase in human malignant melanoma]

A glycosyltransferase, CMP-N-acetylneuraminic acid : glycoprotein sialyltransferase was found in human malignant melanoma. Activities were measured with desialized glycoprotein as an exogenous acceptor. The enzyme was characterized by means of its pH optimum, 5.5, temperature optimum, 30 degrees C, KM values, 10 muM for the sugar nucleotide and 0.3 mM for desialized glycoprotein. It did not require exogenously added metal ions but was slightly stimulated by Mg2+. It required detergent for optimal activity. The effect of nucleotides and sugar nucleotides on enzyme activity has been investigated.