Levels of NEU3 mRNA and sialidase activities in human melanomas. (A) Levels of NEU3 mRNA. Seven human melanoma cell lines (1, SK‐MEL‐28; 2, SK‐MEL‐130; 3, SK‐MEL‐173; 4, SK‐MEL‐37; 5, MeWo; 6, SK‐MEL‐31; 7, SK‐MEL‐23) and six human colon cancer cell lines (8, DLD‐1, 9; Colo320, 10; CACO‐2; 11, SW1080; 12, HT‐29; 13, LoVo) were analysed by real‐time RT‐PCR. Note that five melanoma cells expressed high levels of NEU3 mRNA. (B) Sialidase activities in melanoma cells. Sialidase activities in melanoma cells were assayed with gangliosides as substrates and presented as units/mg protein (1 unit = nmol/h). The right panel is sialidase activity of a colon cancer cell line, DLD‐1, that was reported by Kakugawa et al.
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) (C) Ganglioside composition of human melanoma cells. Thin‐layer chromatography and resorcinol spray pattern of gangliosides in five melanoma cell lines. M, bovine brain ganglioside mixture; 1, SK‐MEL‐37; 2, SK‐MEL‐23; 3, SK‐MEL‐173; 4, SK‐MEL‐28; 5, MeWo.