A New Human Highly Tumorigenic Neuroblastoma Cell Line with Undetectable Expression of N-myc1

A peculiar human cell line (GI-ME-N) derived from the metastatic bone marrow of a 2-yr-old patient with stage IV neuroblastoma (NB) was extensively characterized. Cell-type-specific markers, tumorigenicity in nude mice, morphology, cytogenetics, and amplificationexpression of the N-myc gene were evaluated. All metaphases presented the typical 1p deletion. Surface markers specific for NB cells, vimentin, and neurofilament proteins were all clearly detectable with immunofluorescence andor western blot procedures. Moreover, it was found that GI-ME-N cells did not express N-myc oncogene or HLA class 1 antigens, and were not classified as peripheral neuroectodermal tumor cells. However, extremely short latency and survival times, comparable to peripheral neuroectodermal tumor cells, were observed in nude mice grafted with GI-ME-N. In addition, no correlations were. observed in tumorigenicity of N-myc amplified (IMR32) versusunamplified (SK-N-SH GI-ME-N) human NB cell lines in nude mice. We conclude that N-myc amplification expression do not correlate with the aggressiveness of human NB in athymic animals, which is not always explained by the peripheral neuroectodermal tumor cell nature of the malignant cells, either.