Ectosialyltransferase activity: a marker for certain human haematopoietic cells.


Ectosialyltransferase which can add sialic acid to cell surface acceptor proteins is found in many cells and its activity is elevated in transplantable and metastasizing tumour cells (Dobrossy et al., 1981). Its presence on the surface of L1210 leukaemia cells has been confirmed ultrastructurally (Porter & Bernacki, 1975). Recently Maca & Hakes (1978) have reported high activity of this enzyme in two human B-cell lines as compared to two human leukaemic T-cell lines. In order to determine the value of this enzyme as a marker for certain haematopoietic cells or their differentiation, we have examined ectosialyltransferase activity in 23 immunologically characterized human cell lines of normal and various leukaemia/lymphoma origin which represent cells at different levels of maturation (Minowada et al., 1981). Twenty-three human cell lines, 3 of normal and 20 of various leukaemia/lymphoma origin were examined. The immunological characteristics of these cell lines, their origin and their differentiation stage have been described (Minowada et al., 1981). All cell lines were grown in RPMI 1640 medium containing 5% heat inactivated foetal calf serum and maintained in log phase of growth by appropriate feeding. At harvest, the cell viability as determined by trypan blue exclusion test was 9095%. Ectosialyltransferase activity was determined according to the procedure of Maca & Hakes (1978) with some modifications. Pelleted cells were washed with 50mm N-2-hydroxy ethyl piperazineN', 2-ethanesulfonic acid (HEPES), pH 6.5 containing 0.9% NaCl and 10mm CaCI2. One half of the cells remained untreated whereas the other half of cells was treated with 10 units of VIbrio cholerae neuraminidase (Calbiochem. Behring Corp.) for 30min at 37°C, pelleted by centrifugation (800 g) and washed with 50mm HEPES, pH 6.5, containing 0.9% NaCl. Untreated and neuraminidase treated cells (5 x 106) were suspended in 0.5ml of 50mM HEPES, pH 6.5-0.9% NaCl containing 0.1ICi of CMP-sialic acid [sialic-4, 5,

DOI: 10.1038/bjc.1983.19

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@article{Rossowski1983EctosialyltransferaseAA, title={Ectosialyltransferase activity: a marker for certain human haematopoietic cells.}, author={Wojciech J Rossowski and B. I. Sahai Srivastava}, journal={British Journal of Cancer}, year={1983}, volume={47}, pages={158 - 160} }