Amplification units containing human N-myc and c-myc genes.

The amplification units in human tumors containing amplified myc genes were examined. The amplification unit in all cases consisted of a large genomic region coamplified with the coding region of the myc genes themselves. In eight independent neuroblastomas containing N-myc amplifications, the amplification unit was estimated to be 290 to 430 kilobases.

Expression of GD2 ganglioside by untreated primary human neuroblastomas.

Primary neuroblastomas obtained before therapy from 36 patients were studied to determine the frequency of tumors expressing a specific glycosphingolipid, GD2 ganglioside. Total tissue gangliosides were purified by a new partition method, quantitated, and analyzed by high-performance thin-layer chromatography. All 36 neuroblastoma tumors, representing all clinical stages, contained GD2 ganglioside.

Gene amplification in human neuroblastomas: basic mechanisms and clinical implications.

Extrachromosomal double minutes (DM) and homogeneously staining regions (HSR) of metaphase chromosomes have been reported frequently in human neuroblastomas and tumor derived cell lines. We and other investigators have determined that virtually all DM- and HSR-bearing neuroblastoma cell lines have multiple copies of the oncogene N-myc. Circumstantial evidence suggests that the extrachromosomal DM may be the level at which amplification takes place, with subsequent linear integration into HSR.

Association of multiple copies of the N-myc oncogene with rapid progression of neuroblastomas.

Eighty-nine patients with untreated primary neuroblastomas were studied to determine the relation between the number of copies of the N-myc oncogene and survival without disease progression. Genomic amplification (3 to 300 copies) of N-myc was detected in 2 of 16 tumors in Stage II, 13 of 20 in Stage III, and 19 of 40 in Stage IV; in contrast, 8 Stage I and 5 Stage IV-S tumors all had 1 copy of the gene (P less than 0.01).

Prognostic importance of serum ferritin in patients with Stages III and IV neuroblastoma: the Childrens Cancer Study Group experience.

Ferritin was measured in sera obtained at diagnosis from 241 patients with neuroblastoma to determine (a) the incidence of elevated ferritin and (b) the relationship between ferritin level and outcome. Ferritin was infrequently elevated in sera from patients with Stages I and II disease but was abnormally elevated in 37 and 54% of those with Stages III and IV neuroblastoma, respectively. The mean and median levels for each stage were compared and were highest for Stages III and IV disease.

Immunodiagnosis and immunotherapy of childhood malignancies.

Recent advances in immunologic techniques have allowed the generation of monoclonal antibodies against antigens on tumor cells and their normal counterparts. Monoclonal antibodies useful for diagnosing and defining subtypes of acute leukemias and neuroblastoma have been prepared, although the prognostic significance of the subtypes defined by such antibodies remains to be determined. The usefulness of these reagents for therapeutic purposes either ex vivo, in association with autologous bone marrow transplantation, or in vivo, as carriers of cytotoxic agents, is currently under investigation.

Differential amplification, assembly, and relocation of multiple DNA sequences in human neuroblastomas and neuroblastoma cell lines.

DNA amplification, manifested by homogeneously staining regions in chromosomes and by extrachromosomal, double minute bodies, is characteristic of many neuroblastoma cell lines. Sequences recruited from a specific domain on the short arm of chromosome 2 (2p) are amplified in advanced-stage primary neuroblastomas, whereas sequences from distinctly different regions of 2p are amplified in the neuroblastoma cell line IMR-32. Five different DNA segments, which include the oncogene N-myc, three other fragments derived from the homogeneously staining region of the neuroblastoma cell line IMR-32, and a fifth fragment, derived from the neuroblastoma cell line NB-9, showed differential and variable amplification in 24 advanced-stage neuroblastoma tumors out of 112 tested specimens.

Analysis of neuroblastoma cell proteins using two-dimensional electrophoresis.

Polypeptide patterns of nine neuroblastoma and thirteen other cell lines were analyzed by 2-D PAGE. Of 600 polypeptide spots scored one was present in all neuroblastoma cell lines and none of the other cell types analyzed. Three were markedly increased in intensity in neuroblastoma relative to other cell lines, and one was markedly decreased in neuroblastoma and melanoma.

Altered expression of cell surface membrane antigens in a common acute lymphoblastic leukemia-associated antigen-expressing neuroblastoma cell line (SJ-N-CG) with morphological differentiation.

The expression of common acute lymphoblastic leukemia antigen (CALLA) on a human neuroblastoma cell line, SJ-N-CG, was demonstrated by indirect membrane immunofluorescence, complement-dependent cytotoxicity, and quantitative absorption, using two monoclonal antibodies (J-5 and BA-3) directed against CALLA. Immunoprecipitation of solubilized 125I-labeled membrane proteins from SJ-N-CG cells with J-5 antibody revealed a protein with a molecular weight of 100,000 as determined on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Morphological differentiation of SJ-N-CG cells could be induced in the presence of 2.

Amplification of N-myc in untreated human neuroblastomas correlates with advanced disease stage.

A domain of DNA designated N-myc is amplified 20- to 140-fold in human neuroblastoma cell lines but not in cell lines from other tumor types. N-myc has now been found to be amplified in neuroblastoma tissue from 24 of 63 untreated patients (38 percent). The extent of amplification appears to be bimodal, with amplification of 100- to 300-fold in 12 cases and 3- to 10-fold in 10 others.

A monoclonal antibody recognizing human Thy-1: distribution on human and non-human primate haematopoietic cells.

A monoclonal antibody designated 'antibody 390' (Ab 390) with anti-human Thy-1 reactivity was prepared by the hybridoma technique from the splenocytes of BALB/c mice immunized with human fetal brain. This antibody was shown to have anti-human Thy-1 reactivity because (1) it precipitated a molecule with a molecular weight of about 24,000 daltons, (2) it had a pattern of reactivity similar to that of previously described anti-human Thy-1 antibodies and (3) purified human Thy-1 antigen specifically inhibited binding of Ab 390 to a known antigen-positive cell line. It was the intent of this study to investigate the distribution of Thy-1 on normal and malignant haematopoietic cells in humans and non-human primates.

Effects of retinoic acid (RA) on the growth and phenotypic expression of several human neuroblastoma cell lines.

It has been shown that retinoic acid (RA) can promote morphologic differentiation and inhibit the growth of a human neuroblastoma cell line, LA-N-1. The present study tests the histological generality of these phenomena by determining the effects of RA on seven other human neuroblastoma cell lines. Results show that RA strongly inhibited anchorage-dependent growth and induced morphologic alterations in six of seven of the cell lines.

Raised neuron-specific enolase in serum of children with metastatic neuroblastoma. A report from the Children's Cancer Study Group.

Serum levels of neuron-specific enolase (NSE) were measured by radioimmunoassay at diagnosis in 122 children with widespread metastatic neuroblastoma (clinical stage IV). 96% of these patients had NSE levels more than three standard deviations above the mean for age-matched normal children. Mean serum NSE was 207 +/- SD257 ng/ml (range 10-1240 ng/ml), whereas that in normal age-matched children was 7.

Neuroblastoma: clinical perspectives, monoclonal antibodies, and retinoic acid.

Neuroblastoma, the second commonest solid tumor in children, is a neoplasm of the peripheral autonomic nervous system that usually occurs before children are 6 years old. Therapy of localized tumor (clinical stage I and II) and of a special form of metastatic tumor (clinical stage IV-S) is usually successful, but treatment of widespread regional (clinical stage III) or metastatic (clinical stage IV) neuroblastoma is almost uniformly unsuccessful. Unfortunately, two thirds of children have stage III or IV disease at diagnosis.