Beschreibung:
<jats:title>Abstract</jats:title><jats:p>A continuous human cell line RN‐GA was established from a stage‐III primary neuroblastoma prior to therapy. Light and electron microscopic analysis of the biopsy showed morphological features typical of neuroectodermal origin. Relative cellular DNA content and N‐<jats:italic>myc</jats:italic> oncogene copy number were also analyzed in the biopsy tissue: the tumor cells presented a near‐diploid genome with N‐<jats:italic>myc</jats:italic> amplification. The derived tumor cell line expressed distinctive ultrastructural, cytogenetic and immunological markers of neuroblastoma. Moreover, cells from the culture could be serially transplanted into splenectomized‐irradiated nude mice, where they formed a progressively growing solid tumor. Surprisingly, the cells in culture did not show any N‐<jats:italic>myc</jats:italic> amplification, while they retained a near‐diploid DNA content. We propose that several techniques (electron microscopy, oncogene analysis, flow cytometry, cytogenetics, tissue culture, cell antigen immunodetection) should be used to establish a firm diagnosis and a correct clinical grading of this tumor. The establishment of this continuous cell line should be valuable as an experimental <jats:italic>in vitro</jats:italic> system for further studies of neuroblastoma biology and morphology.</jats:p>