WILD-TYPE AND CULTURED EHRLICH ASCITES TUMOR-CELLS DIFFER IN TUMORIGENICITY, LECTIN-BINDING PATTERNS AND BINDING TO BASEMENT-MEMBRANES

Three different variants of the Ehrlich ascites tumour (EAT) cell were derived and the lectin surface reactivities, as well as the malignant characteristics of each variant, were studied. Wild-type cells (EAT-w t) were selected for growth on basement membranes and tissue culture p lastic to give EAT-c cells. The EAT-c were Passaged in mice by i.p. in jection, giving rise to a third variant (EAT-c/m). Each of these three cell variants was characterized for: (i) specific lectin agglutinabil ity patterns; (ii) the ability to produce ascites tumours in mice; (ii i) the ability to produce solid tumours; and (iv) the attachment to an d growth on basement membranes and purified extracellular matrix molec ules. Analysis of the total protein and carbohydrate content of each c ell line showed that there was an increase in the glycosylation of the EAT-c cells compared to EAT-wt cells. After repeated passage of the E AT-c/m cells in mice, the glycosylation level of the EAT-c/m cells ret urned to that of the EAT-wt cell line. In addition, the EAT-c cells di splayed an increase in the number of terminal non-reducing sugars whic h could indicate either an increased degree of branching or the presen ce of additional N- and/or O-linked oligosaccharide chains of the cell ular glycoproteins. This phenotype was retained by the EAT-c/m cells w hich had been passaged repeatedly in mice. The most significant increa se was in the content of sialic acid-containing glycoproteins found in the EAT-c cells. The sialic acid-binding lectin Maackia amurensis leu koagglutinin (MAL) agglutinated all three EAT cell variants, while the sialic acid-binding Sambucus nigra (elderberry bark) lectin (SNA) agg lutinated only the EAT-c and early-passage EAT-c/m cells. These findin gs indicate the presence of alpha 2,3-linked sialic acid on all three variants, but only the cultured cells and early-passage EAT-c/m cells possess the Neu5Ac alpha 2,6,6 linkage. The EAT-c cells attached avidl y to wells coated with either laminin or fibronectin, as well as an ex tracellular matrix produced by cultured bovine endothelial cells, but the EAT-wt and EAT-c/m cells did not. Paradoxically, the EAT-c cells w ere incapable of producing solid tumours when injected into a basement membrane-rich skeletal muscle bed, whereas the EAT-wt and EAT-c/m cel ls produced rapidly growing tumours when injected into the same enviro nment. Lectin agglutination patterns established that ascitic tumour c ells within the peritoneal cavity were derived from injected EAT-c cel ls.