A second, randomly cloned, amplified DNA segment from the HSR of one of the neuroblastoma lines is amplified in a subset of the lines in which NB-19-21 is amplified.
In neuroblastoma lines in which the N-myc gene is present as a single copy, the expression of N-myc as messenger RNA is increased relative to that in nonneuroblastoma cell lines and tumors.
Previous work showed that each of four human neuronal cell lines expresses less than or equal to 0.5% of the HLA-A,B,C and beta 2-microglobulin seen in glial, lymphoid, and other cell types, and there is a corresponding weak expression in neuroblastoma tumor and adult brain.
In contrast, three tumor types, teratocarcinoma, choriocarcinoma, and neuroblastoma, were not inducible for Ia expression, even though IFN-gamma could induce expression of HLA-A,B,C products.
Previous work showed that each of four human neuronal cell lines expresses less than or equal to 0.5% of the HLA-A,B,C and beta 2-microglobulin seen in glial, lymphoid, and other cell types, and there is a corresponding weak expression in neuroblastoma tumor and adult brain.
N-myc is a DNA sequence which shares limited homology to the proto-oncogene c-myc and has been found to be amplified in both primary tissue and cell lines from neuroblastoma, a childhood tumour of neuroectodermal origin.
We have analyzed a 3.8 kb Eco RI fragment of genomic DNA obtained from the amplified N-myc gene of human neuroblastoma cell line BE(2)-C. This fragment contains an exon with an open reading frame encoding approximately 170 amino acids of the carboxy-terminal end of the putative N-myc protein.
The N-myc gene, first detected by its homology to the second exon of the c-myc gene, is amplified and/or expressed in tumours or cell lines derived from neuroblastoma, retinoblastoma and SCLC.
The N-myc gene, first detected by its homology to the second exon of the c-myc gene, is amplified and/or expressed in tumours or cell lines derived from neuroblastoma, retinoblastoma and SCLC.
K117, the putative human Thy-1 antigen, was expressed at high levels in chromosome 11-containing hybrids constructed with mouse neuroblastoma cells, but showed little or no expression in hybrids constructed with mouse L cells.
We have demonstrated that the entire murine N-myc gene and the sequences necessary for its expression in human neuroblastoma cells are contained within a 7.4-kilobase murine genomic clone.