C16 laminin peptide increases angiotropic extravascular migration of human melanoma cells in a shell-less chick chorioallantoic membrane assay.

BACKGROUND: As distinct from intravascular dissemination, extravascular migratory metastasis (EVMM) has been described as a potential additional mechanism of melanoma spread in which tumour cells migrate along the external surfaces of vessels. Recent experimental studies strongly suggest a correlation of angiotropism of melanoma cells with EVMM. Angiotropic melanoma cells are linked to the endothelium by an amorphous matrix confirmed to contain laminin.
OBJECTIVES: To investigate whether laminin plays a role in this extravascular mechanism of tumour spread.
METHODS: We tested the effect of the C16 laminin peptide on melanoma spread in a shell-less chick chorioallantoic membrane model.
RESULTS: After 3 days, green fluorescent protein-expressing melanoma cells were observed spreading along or in the immediate proximity of vessels. The C16 laminin peptide significantly lengthened the distance of extravascular, angiotropic migration of melanoma cells. Histopathology confirmed the angiotropism of melanoma cells without intravasation, compatible with that observed with human angiotropic melanoma.
CONCLUSIONS: The results of this study suggest that the C16 laminin gamma1 chain peptide has angiotropic, extravascular migration-promoting activity on human melanoma cells, and might be a molecular target for preventing melanoma metastasis.