Human SK-Mel 28 melanoma cells resume neural crest cell migration after transplantation into the chick embryo.

Melanocytes are derived from the neural crest. We questioned whether the migratory mechanism during the invasive growth of melanoma cells is the same as that in neural crest cell migration. We transplanted human SK-Mel 28 melanoma cells into the neural tube of the chick embryo stage 11-13 and, after up to 6 days of total incubation, traced the cells by immunohistochemistry in serial paraffin sections. SK-Mel 28 cells were integrated into the host neural crest and were found in the roof plate of the neural tube, along the medial neural crest cell pathway, in the sclerotome and, finally, in developing sympathetic ganglia. At stage 21, massive segmental emigration between myotome and disintegrating dermatome was observed at the level of the upper limb bud. The melanoma cells, in contrast with the chick neural crest cells, were HNK-1-negative. They retained the premelanosome epitope HMB-45. For definite identification and exclusion of fusion with chick embryo cells, in situ hybridization with the human-specific Alu sequence was performed. The results showed that human SK-Mel 28 melanoma cells were capable of resuming neural crest cell migration in the embryo.