Ganglioside expression in lung cancer cell lines.

Gangliosides are complex glycolipid constituents of cell membranes. They are involved in many biological functions including cell-cell recognition, cell-matrix attachment, cell growth and cell differentiation. Analysis of tumor associated gangliosides may aid in the characterisation of tumour cells and their degree of malignant transformation. We have characterised a total of eight lung cancer cell lines (four small cell and four non-small cell lung cancer) with respect to ganglioside and alpha v integrin receptor expression. Ganglioside GD3 was detected using the monoclonal antibody R24. Ganglioside GM1 was detected using the beta-subunit of cholera toxin. Ganglioside 9-O-acetyl GD3 and the alpha v integrin receptor were measured using commercially available monoclonal antibodies. Our results indicate that small cell lung cancer cell lines express significant levels of GD3 and 9-O-acetyl GD3. Ganglioside GM1 and alpha v integrin receptor were not specific to any histological subtype. The expression of ganglioside GM1 and GD3 was independent of cell-cycle phase. We conclude that GD3 and 9-O-acetyl GD3 expression may be additional markers of the Small Cell Lung Cancer phenotype, but their significance is unknown. Therefore a characteristic ganglioside pattern cannot be defined according to histological subtype. alpha v integrin receptor expression is not unique to cells expressing GD3.