N-glycans influence the in vitro adhesive and invasive behaviour of three metastatic cell lines

Alterations in cellular glycosylation may play a key role in metastatic beh aviour of tumour cells. We studied three metastatic cell lines, LOX (malign ant melanoma), FEMX (malignant melanoma) and MA-11 (mammary carcinoma). The se cell lines have a very different metastatic behaviour in vivo, and diffe rent glycans have been postulated to be partly responsible for these differ ences. To further investigate the functional role of carbohydrates, these t hree cell lines have been treated with tunicamycin, an inhibitor of the bio synthesis of N-glycans and benzyl-alpha-N-acetylgalactosamine (benzyl-alpha -GalNAc; BnGalNAc), an inhibitor of mature O-linked glycans. Various in vit ro adhesion and invasion assays were undertaken for functional studies. Tun icamycin significantly inhibited adhesion to laminin, but only slightly aff ected cell adhesion to collagen IV. The same compound significantly decreas ed cellular invasiveness through a Matrigel invasion chamber. Moreover, tun icamycin reduced homotypic aggregation of cells. BnGalNAc had generally lit tle effect on cell behaviour in in vitro assay. The effects of the inhibito rs were, however, to some extent cell line-specific. We conclude that N-gly cans, but probably not mature O-glycans have important in vitro functions i n cell adhesion to laminin, cell invasion through Matrigel and cellular agg regation in the studied cell lines. These results support the view that car bohydrates are functionally involved in several steps of the metastatic pro cess. Copyright (C) 2000 S. Karger AG, Basel.