CYTOGENETIC FEATURES OF HUMAN NEUROBLASTOMAS AND CELL-LINES

Abstract

The banded karyotypes of 24 human neuroblastomas and cell lines were studied to identify any consistent chromosomal abnormalities. Six of the 10 primary tumors and 1 of the 14 cell lines were studied at this institution. Of the 24 neuroblastomas karyotyped, 20 were near-diploid, 1 was near-triploid, and 3 were near-tetraploid. One primary tumor had a diploid karyotype without numerical or structural rearrangements. The 20 cases with a karyotype in the diploid range were statistically analyzed for gain or loss of whole chromosomes and for structural abnormalities of each chromosome arm. The short arm of chromosome 1 was preferentially involved in structural rearrangements, occurring in 14 cases (P < 0.01). In 11 of these cases, the abnormality of chromosome 1 included deletion of bands 1p32 .fwdarw. 1pter, rendering the cells monosomic for this genetic material. Of the remaining 3 cases, 1 involved a reciprocal translocation of chromosomes 1p and 12q, another had insertion of genetic material at band 1p13, and the 3rd had an extra dark band at 1p36. No other numerical or structural abnormalities occurred with sufficient frequency to reach statistical significance (P > 0.20). Six of the primary tumors or cell lines in the diploid range had double minute chromatin bodies, 4 cell lines had homogeneously staining regions, and 2 cell lines had double minute chromatin bodies or homogeneously staining regions in subpopulations of cells. Partial monosomy for the short arm of chromosome 1 was the most consistent cytogenetic abnormality in the human neuroblastomas studied.