A neuroblastoma cell line derived from a case detected through a mass screening system in Japan: A case report including the biologic and phenotypic characteristics of the cell line

BACKGROUND. A mass screening system in Japan, which involves measuring urinary catecholamine metabolites, has resulted in an increasing number of cases of neuroblastoma, most of which have favorable biologic properties and some of which are associated with tumor regression or involution. At the time this study was begun, the characteristics and biologic nature of the neuroblastomas had not been fully defined, because a cell line had not yet been established with tumor tissue taken from a neuroblastoma detected in the mass screening. METHODS. The authors established a cell line by tissue culture for over 50 generations from a neuroblastoma found during mass screening, which was characterized by favorable histology, with a triploid DNA stemline and without N-myc gene amplification. The morphologic and biologic characteristics of the new cell line were investigated in vitro. RESULTS. The cell line, designated MASS-NB-SCH-1, has neuronal properties, such as neurite-like processes and neurofilaments, as well as the expression of vimentin and fibronectin in studies of the cell morphology and immunohistochemistry. Karyotype analysis detected the presence of 42-46 chromosomes, with a deletion of the short arm of 1 of the 3 copies of chromosome 1. DNA ploidy was near-diploid in association with 20-fold amplification of N-myc genes. CONCLUSIONS. The cell line has a nature distinct from the original tumor tissue. It may be characterized by phenotypic change caused by clonal selection or evolution of aggressive, proliferative properties of the neuroblastoma in relation to the N-myc amplification mechanism.