Enhanced CMP‐NeuAc:Galβ1, 4GlcNAc‐R α2, 6 sialyltransferase activity of human colon cancer xenografts in athymic nude mice and of xenograft‐derived cell lines

The activity of an α2,6 sialyltransferase acting on N‐acetyllac‐tosaminic sequences (α2,6 ST E.G. 2.4.99.1) has previously been found to be increased in 90% of human colon cancer specimens. In the present study, the α2,6 ST activity of 6 human colon cancer cell lines grown in culture was compared with that expressed by the corresponding nude mice xenografts and by the cell lines derived from the xenografts. We found that xenografts of COLO 205, HT‐29, SW 620, SW 948 and SW 948 FL (a non‐adherent sub‐line of SW 948) cells express an α2,6 ST activity much higher than that of the in vitro‐grown cells. SW 48 cells grown either in culture or as xenografts lack the enzyme activity. All the xenograft‐derived cell lines except HT‐29 retained the increased α2,6 ST activity at least for the first 6 passages. Those derived from SW 948 xenografts showed an enrichment of round, non‐adherent cells, strongly reactive with the NeuAcα2,6Gal/GalNAc‐specific lectin from Sambucus nigra (SNA), thus indicating that a selection of these cells has occurred. Copyright © 1992 Wiley‐Liss, Inc., A Wiley Company