Lectin CGL from the sea mussel Crenomytilus grayanus induces Burkitt's lymphoma cells death via interaction with surface glycan

Marine organisms are rich sources of lectins. Lectins are able to bind specifically and reversibly to different types of carbohydrates or glycoproteins. The present study reports the evaluation of glycan binding profile and anti-tumor potential of lectin CGL from the sea mussel Crenomytilus grayanus. Glycan array assay revealed that CGL was able to bind both α and β anomer of galactose, but interaction with the αGal-terminated glycans was stronger. Analysis of most common glycan motifs for CGL showed high affinity to Galα1-4Galβ1-4GlcNAc motif similar to globotriose structure (Gb3: Galα1-4Galβ1-4Glc), the epitope of globotriaosylceramide. CGL recognized Gb3 on the surface of Burkitt's lymphoma Raji cells (high Gb3 expression), leading to dose-dependent cytotoxic effect, G2/M phase cell cycle arrest and apoptosis. Lectin had no effect on erythroleukemia K562 cells (no Gb3 expression). The activity of CGL was specifically blocked by α-galactoside. Our findings suggest the use of CGL in cancer diagnosis and treatment.