This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kanani, A. Articles by Baker, M. A. Search for Related Content PubMed PubMed Citation Articles by Kanani, A. Articles by Baker, M. A.

Human Leukemic Myeloblasts and Myeloblastoid Cells Contain the Enzyme Cytidine 5'-Monophosphate-N-acetylneuraminic Acid:Galß1-3GalNac(2–3)-sialyltransferase¹

Department of Medicine, Toronto General Hospital, University of Toronto, Ontario M5G 2C4, Canada [A. K., D. R. S., M. A. B]; Department of Haematology, Hadassah Hospital, Hebrew University Jerusalem, Israel, IL-91120 [E. F.]; Department of Medicine, Columbia University, New York, New York 10032 [R. N. T.]; Department of Biochemistry, Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8 [I. B., W. K.]; Roswell Park Memorial Institute, Buffalo, New York 14263 [K. L. M]; Division of Oncology-Hematology, Winthrop University Hospital, Mineola, Long Island, New York 11501 [A. H.]; and Department of Medical Chemistry, Vrije Universiteit, Amsterdam, The Netherlands, NL-1007 MC [D. H. v. d. E.]

We have examined the role of CMP-NeuAc:Galß1-3GalNAc-R (2–3)-sialyltransferase in fresh leukemia cells and leukemia-derived cell lines. Enzyme activity in normal granulocytes using Galß1-3GalNAc-o-nitrophenyl as substrate was 1.5 ± 0.7 nmol/mg/h whereas activity in morphologically mature granulocytes from 6 patients with chronic myelogenous leukemia (CML) was 4.2 ± 1.6 nmol/mg/h (P < 0.05). Myeloblasts from 5 patients with CML in blast crisis showed enzyme activity levels of 6.5 ± 2.5 nmol/mg/h. From 2 patients with CML, both blasts and granulocytes were obtained, with higher enzyme activity in the patients' blasts (7.1 nmol/mg/h) than in their granulocytes (4.9 nmol/mg/h) in both cases, suggesting that the increase in enzyme activity is related to the differentiation or proliferation status of the CML cells. However, similarly high enzyme levels were also seen in myeloblasts from acute myeloblastic leukemia patients (5.6 ± 1.4 nmol/mg/h) and in some acute myeloblastic leukemia-derived cell lines (KG1a and HL60), suggesting that increased levels of this enzyme are not directly correlated with the presence of the Ph¹ chromosome. This (2–3)-sialyltransferase activity can also be detected in normal peripheral blood lymphocytes and exhibits increased activity in chronic lymphocytic leukemia cells and acute lymphoblastic leukemia. These data suggest that the level of enzyme activity may vary with growth rate and maturation status in myeloid and lymphoid hemopoietic cells. Finally, we have identified a glycoprotein in acute myeloblastic leukemia cells that serves as a substrate for the (2–3)-sialyltransferase. The desialylated form of the glycoprotein was resialylated in vitro by the purified placental form of this (2–3)-sialyltransferase and exhibits a molecular weight of about 150,000.

¹ Supported by the Medical Research Council of Canada; The National Cancer Institute of Canada; National Cancer Institute Grants CA31762 and CA35329; the William J. Matheson Foundation; and the Canadian Cystic Fibrosis Foundation.

² To whom requests for reprints should be addressed, at Toronto General Hospital, Mulock Larkin Wing 1-005, 200 Elizabeth Street, Toronto, Ontario, M5G 2C4, Canada.

Received 11/ 7/89. Revised 3/16/90.