HELIX-POMATIA AGGLUTININ BINDING IN HUMAN TUMOR-CELL LINES - CORRELATION WITH PULMONARY METASTASES IN NUDE-MICE

The extent of lectin binding by three human melanoma (LOX, FEMX-I and SESX) and two sarcoma lines (MHMX and OHSX) was related to their poten tial for experimental metastasis formation in athymic nude mice. The H elix pomatia agglutinin (HPA), which recognises the N-acetyl-D-galacto samine ligand, showed differential binding to the cell lines in a mann er that correlated with their ability to give lung colonies after i.v. injection in the mice (P < 0.005). The degree of HPA binding and lung colony formation of the cell lines studied was ranked in the followin g order, LOX > MHMX > OHSX > SESX > FEMX-I. Similar patterns were not observed with the other lectins used in this study (WGA, Con A, PNA an d UEA-I). The high HPA reacting LOX melanoma line shows extensive pulm onary metastatic formation with no extrapulmonary colonies, whereas th e low HPA reacting FEMX-I cells give only extrapulmonary metastases wi th no detectable colonies in the lungs. Precoating of tumour cells wit h HPA prior to injection did not reduce the ability of cells to give p ulmonary metastases, suggesting that the HPA epitope was not functiona lly associated with the pulmonary metastatic potential observed in nud e mice. These findings support recent human studies of a correlation b etween HPA binding and incidence of metastasis, however, our data indi cate that there is no causal relationship. Further analyses are requir ed to identify the specific HPA-binding glycoconjugates that may be in volved.