Human atrial natriuretic peptides (ANP) gene locus: BglI RFLP

Fluorescence in situ hybridization analysis of chromosome 1p36 deletions in human MYCN amplified neuroblastoma

BACKGROUND/PURPOSE

Deletion of the short arm of chromosome 1 (1p) is one of the poor prognostic factors in human neuroblastomas. Recent studies have suggested that one or more of the neuroblastoma tumor suppressor genes reside in this region and have identified the shortest region of overlap (SRO) on 1p36. The purpose of this study was to examine deletions of 1p in human neuroblastomas by fluorescence in situ hybridization (FISH).

METHODS

Two-color FISH analysis was performed to detect chromosome 1p36 abnormalities in 42 MYCN-amplified neuroblastomas. Four different probes from the 1p36 region, the E2F2, NPPA, D1S160, and CDC2L1 loci were used for detection of 1p abnormalities. A repeat sequence probe, which is specific for the heterochromatic region of chromosome 1 (pUC1.77), was used as a control.

RESULTS

Large deletions of 1p36 were observed in 31 (73.8%) of 42 tumors, whereas the remaining 11 (26.2%) showed no deletion. In these 11 tumors, a translocation of 1p was found in one and a duplication of 1p was detected in another.

CONCLUSIONS

A strong correlation between 1p abnormalities and MYCN amplification was found in this study. MYCN-amplified neuroblastomas were found to show large deletions of 1p encompassing the SRO. FISH provided a rapid and reliable method to detect hemizygous deletions of 1p.

No effect on blood pressure level or variability of polymorphisms in DNA at the locus for atrial natriuretic factor (ANF)

We have examined healthy Norwegians with respect to two restriction fragment length polymorphisms at the locus for atrial natriuretic factor, detectable with the restriction enzymes XhoI and BglI, respectively. No association with systolic or diastolic blood pressure level or variability was found. Thus, the normal genes detected by examination of these restriction fragment length polymorphisms have neither "level gene" nor "variability gene" effects on normal blood pressure.

Linkage mapping of the tumor necrosis factor receptor 2 (TNFR2) gene to 1p36.2 using the single-strand conformation polymorphism technique

We identified two informative polymorphisms in the transcribed 3' untranslated region of the tumor necrosis factor receptor 2 (TNFR2) gene using the polymerase chain reaction (PCR) with the single-strand conformation polymorphism (SSCP) technique. These polymorphisms demonstrated Mendelian inheritance and were useful for linkage analysis. TNFR2 was very closely linked to the pronatriodilatin gene (PND), and the TNFR2 SSCP polymorphisms were much more informative than the restriction fragment length polymorphisms currently available for the PND locus. In addition, we have demonstrated that genotyping could be performed with DNA obtained from paraffin-embedded tissue.

Constitutional 1p36 deletion in a child with neuroblastoma

We describe a child with dysmorphic features, as well as developmental and growth delay, who developed neuroblastoma at 5 mo of age. Cytogenetic analysis of blood lymphocytes revealed an interstitial deletion of 1p36.1-->1p36.2, which was apparent only with high-resolution banding. Molecular analysis with a collection of polymorphic DNA probes for 1p confirmed an interstitial deletion involving subbands of 1p36. Deletions of this region are a common finding in neuroblastoma cells from patients with advanced stages of disease. Therefore, these results (a) suggest that constitutional deletion of this region predisposed the patient to the development of neuroblastoma and (b) support the localization of a neuroblastoma tumor-suppressor locus to 1p36.

Loss of allelic heterozygosity on distal chromosome 1p in Merkel cell carcinoma. A marker of neural crest origins?

The location of genes involved in tumor evolution has been inferred from experiments in which loss of constitutional heterozygosity has been detected in tumor DNA at high frequency in specific chromosome regions. For example, cytogenetic and molecular abnormalities on chromosome 1p have been reported in tumors such as malignant melanoma and neuroblastoma which arise in cells derived from embryonic neural crest tissue. To extend these observations, we have examined tumor DNA from three cases of Merkel cell carcinoma for evidence of loss of constitutional heterozygosity on the short arm of chromosome 1. In all three cases, heterozygous allelic deletions of varying extent on distal chromosome 1p were detected in tumor DNA. Comparisons with neural crest tumors suggest that loss of heterozygosity on distal chromosome 1p in Merkel cell tumors may be a marker of neural crest origin.

Loss of alleles from the distal short arm of chromosome 1 occurs late in melanoma tumor progression

The gene for familial malignant melanoma and its precursor lesion, the dysplastic nevus, has been assigned to a region of the distal short arm of chromosome 1, which is frequently involved in karyotypic abnormalities in melanoma cells. We have examined loci on chromosome 1p for loss-of-constitutional heterozygosity in 35 melanomas and 21 melanoma cell lines to analyze the role of these abnormalities in melanocyte transformation. Loss-of-heterozygosity at loci on chromosome 1p was identified in 15/35 (43%) melanomas and 11/21 (52%) melanoma cell lines. Analysis of multiple metastases derived from the same patient and of melanoma and lymphoblastoid samples from a family with hereditary melanoma showed that the loss-of-heterozygosity at loci on distal 1p is a late event in tumor progression, rather than the second mutation that would occur if melanoma were due to a cellular recessive mechanism. Comparisons with neuroblastoma and multiple endocrine neoplasia (MEN2) suggest that the frequent 1p loss-of-heterozygosity in these malignancies is a common late event of neuroectodermal tumor progression.

Loss of heterozygosity for the short arm of chromosome 1 in human neuroblastomas: correlation with N-myc amplification

Partial monosomy of the short arm of chromosome 1 is the most consistent cytogenetic abnormality found in human neuroblastomas, but its overall frequency and significance are unclear. Using a panel of chromosome-1-specific DNA probes that identify restriction fragment length polymorphisms, we demonstrate that 13 of 47 human neuroblastomas (28%) have somatic loss of heterozygosity (LOH) at one or more loci on the distal short arm of chromosome 1. the chromosomal region that shows LOH most consistently is between 1p36.1 and 1p36.3; loss of a gene or genes in this region may be critical for the development or progression of neuroblastomas. The region of LOH in human neuroblastoma may resemble that described for pheochromocytoma, medullary thyroid carcinoma, and melanoma, which are also tumors of neural-crest origin. Although LOH for distal chromosome 1p can occur in early stages of neuroblastoma, the loss usually occurs in tumors of advanced clinical stages. LOH for the short arm of chromosome 1 correlates significantly with N-myc amplification, suggesting that these two genetic events are related. Indeed, these two lesions appear to characterize a genetically distinct subset of particularly aggressive neuroblastomas.

NsiI and ScaI restriction fragment length polymorphisms at the atrial natriuretic peptides (ANP) gene locus

The authors report on two new restriction fragment length polymorphisms at the human atrial natriuretic peptide gene locus, detected in three families with restriction endonucleases ScaI and NsiI.

A genetic linkage map of 27 loci from PND to FY on the short arm of human chromosome I

A genetic linkage map of 27 loci on the short arm of human chromosome 1 has been developed by analysis of the 40 families in the Centre d'Etude du Polymorphisme Humain (CEPH) reference panel. Probes that recognize 14 novel RFLPs at loci designated D1S9-D1S22 were isolated from a flow-sorted chromosome 1 library. A linkage map of chromosome 1p was constructed from the genotypic data at these 14 loci, RFLPs at eight cloned genes (PND, ALPL, FUCA1, SRC2, MYCL, GLUT, TSHB, and NGFB), two previously identified RFLPs (D1S2 and D1S57), two blood group antigens (RH and FY), and the isozyme PGM1. All 27 loci form a continuous linkage group, from FY to PND, of 102 cM in males and 230 cM in females. This map provides a basis for highly informative multipoint mapping studies for most of the short arm of chromosome 1.