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Biomedical subjects

D Pinkel

Publications and source records attributed to D Pinkel.

At least 91 records · Page 5Linked to original sources

ERBB2 amplification in breast cancer analyzed by fluorescence in situ hybridization.

We illustrate the use of fluorescence in situ hybridization (FISH) for analysis of ERBB2 oncogene copy number, the level of amplification (here defined as the ratio of ERBB2 copy number to copy number of chromosome 17 centromeres), and the distribution of amplified genes in breast cancer cell lines and uncultured primary breast carcinomas. The relative ERBB2 copy number determined by FISH in 10 breast cancer cell lines correlated strongly with Southern blot results (r = 0.98) when probes for an identical reference locus were used in the two methods. Metaphase analysis of cell lines showed that amplified ERBB2 copies always occurred in intrachromosomal clusters but that the number and chromosomal location of these clusters varied among the cell lines. In interphase nuclei of primary tumors showing ERBB2 amplification (10/44), ERBB2 copies were seen as one to four clusters, also suggesting intrachromosomal localization. Regardless of the average level of amplification, all these tumors contained highly amplified cell subpopulations with at least 25, and sometimes more than 100, ERBB2 copies per cell. Tumors that did not show amplification by FISH (34/44) had an average of one to five ERBB2 copies scattered randomly in the nuclei and completely lacked cells with high copy levels. FISH results on primary tumors were concordant with slot blot results on amplification and with immunohistochemical detection of overexpression. Quantitative analysis of ERBB2 amplification by FISH may improve prognostic assessments based on the pattern of amplification and detection of heavily amplified tumor cell subpopulations.

Breast Neoplasms↗

Deletion of chromosome 17p loci in breast cancer cells detected by fluorescence in situ hybridization.

Allelic loss of tumor suppressor genes on chromosome 17p has been implicated in the progression of breast cancer. This is in principle detectable by fluorescence in situ hybridization if the loss occurs by deletion. In order to determine if detectable deletions occur in primary breast cancer, we used dual-color hybridization with chromosome 17 pericentromeric and region-specific DNA probes to study 19 primary breast cancers. The copy numbers of 17 centromere and 17p13.1 sequences were compared with the loss of heterozygosity (LOH) for probe YNZ22 at 17p13.3 detected by restriction fragment length polymorphism. Nine of 11 cases showing LOH also showed the major population of nuclei with a deletion. The remaining two tumors with LOH were trisomic for both the centromere and 17p13.1 cosmid. In contrast, seven of eight tumors without LOH had no deletions by fluorescence in situ hybridization. These data suggest that the dominant mechanism of allelic loss at 17p in breast cancer is a physical deletion and that analysis of deletions by fluorescence in situ hybridization is a rapid and sensitive approach to studying chromosomal aberrations.

Alleles↗

Molecular cytogenetics in human cancer diagnosis.

This report summarizes the application of fluorescence in situ hybridization for detection and diagnosis of human cancers and for detection of residual cancer cells. This approach allows individual interphase cancer cells to be stained so that aberrations such as aneusomies, translocations, deletions, and gene amplification can be seen in the light microscope. This is accomplished using probes for repeated sequences found at the chromosome centromeres, whole chromosome probes, and/or probes for specific aberrant sequences.

Chromosome Aberrations↗

Molecular cytogenetics: diagnosis and prognostic assessment.

This review describes molecular cytogenetic techniques for detection and characterization of genetic aberrations associated with human disease. The techniques of fluorescence in situ hybridization, primed in situ labeling and comparative genome hybridization are described, as are probes for repeated sequences, whole chromosomes and specific loci. Also reviewed are applications of these technologies to pre- and neonatal diagnosis and to the characterization of human malignancies.

Base Sequence↗

Lessons from 20 years of curative therapy of childhood acute leukaemia.

The past 20 years of curative therapeutics of childhood acute leukaemia has been largely a period of consolidation of gains, refinement of techniques and dissemination of expertise and technology. However, certain lessons have been learned. First, cure can be permanent but the complexity and cost of curative treatment currently restricts its accessibility; prevention or simple curative treatment is needed. Secondly, cure of the child demands that the risk of adverse sequelae of treatments be carefully balanced with known therapeutic benefits. Thirdly, preventive meningeal irradiation is no longer required. Fourth, treatment intensification is self-limiting. Adverse reactions can cancel out or exceed therapeutic benefits, resulting in a lower cure rate or a similar cure rate with lower quality of cure. Finally, morphology, immunophenotype and genotype of acute leukaemia are important criteria for selecting and scheduling drug therapy. Genotype may be the most important since leukaemia is a genetic disorder for which morphology and immunophenotype are mere reflections. However, none of these features, individually or together, are sufficient to explain all the difference in outcome among children on a given treatment plan or to completely fulfill the need of criteria for selection of treatment. Acute leukaemia remains an unsolved problem demanding considerably more basic and clinical research to meet the need for prevention and simple dependable curative treatment.

Acute Disease↗

Rapid translocation frequency analysis in humans decades after exposure to ionizing radiation.

This paper presents an analysis of the utility of fluorescence in situ hybridization (FISH) with whole-chromosome probes for measurement of the genomic frequency of translocations found in the peripheral blood of individuals exposed to ionizing radiation. First, we derive the equation: Fp = 2.05fp(1-fp)FG, relating the translocation frequency, Fp, measured using FISH to the genomic translocation frequency, FG, where fp is the fraction of the genome covered by the composite probe. We demonstrate the validity of this equation by showing that: (a) translocation detection efficiency predicted by the equation is consistent with experimental data as fp is changed; (b) translocation frequency dose-response curves measured in vitro using FISH agree well with dicentric frequency dose-response curves measured in vitro using conventional cytogenetic procedures; and (c) the genomic translocation frequencies estimated from FISH measurements for 20 Hiroshima A-bomb survivors and four workers exposed to ionizing radiation during the Y-12 criticality accident are approximately the same as the translocation frequencies measured using G-banding. We also show that translocation frequency dose response curves estimated using FISH are similar for Hiroshima A-bomb survivors and for first division lymphocytes irradiated in vitro. We conclude with a discussion of the potential utility of translocation frequency analysis for assessment of the level of acute radiation exposure independent of the time between analysis and exposure.

Accidents↗

Blue rubber bleb nevus syndrome: laser photocoagulation of colonic hemangiomas in a child with microcytic anemia.

This is a case report and review of the literature on the blue rubber bleb nevus syndrome. The clinical features of the syndrome are discussed, with emphasis on chronic gastrointestinal bleeding and resulting anemia. A new therapeutic modality, colonoscopy with laser photocoagulation, is recommended as a safe, effective, and less invasive method of controlling bleeding from colonic hemangiomas than surgical resection and repeated transfusions. This technique is less helpful for patients with prominent involvement of the small intestine.

Anemia↗

Detection of retinoblastoma gene copy number in metaphase chromosomes and interphase nuclei by fluorescence in situ hybridization.

Fluorescence in situ hybridization (FISH) was applied to detect the copy number of the retinoblastoma (RB1) tumor suppressor gene in metaphase chromosomes and interphase nuclei. We used 14 lambda phage clones spanning the whole RB1 gene region as a probe and obtained a specific hybridization signal in normal metaphase chromosomes at 13q14. Normal interphase nuclei showed two RB1 signals in about 90% of cases, whereas two cell lines with cytogenetically defined deletions involving the RB1 gene showed only one hybridization signal in about 80% of the nuclei. Analogous changes were detected in metaphase chromosomes. Multicolor FISH with subsets of the phage clones allowed visualization of subregions within the 200-kb gene in interphase nuclei. Analysis of clinical breast cancer samples showed that most of the cells contained two copies of the RB1 gene, even when restriction fragment length polymorphism analysis showed loss of heterozygosity (LOH) at the RB1 locus. This indicates that LOH at the RB1 locus in breast cancer cells probably involves mechanisms other than physical deletion.

Breast Neoplasms↗

Therapy of acute lymphoid leukemia in children.

The cure rate of childhood acute lymphoid leukemia (ALL) has improved in the past 20 years due to improved treatment of T cell ALL, better infection control and availability of blood components, and more experience. Several these are proposed as treatment guidelines.

Antineoplastic Combined Chemotherapy Protocols↗

Remission induction and continuation therapy in children with their first relapse of acute lymphoid leukemia. A Pediatric Oncology Group study.

Between January 1979 and April 1983, 113 children undergoing their first relapse of acute lymphoid leukemia (ALL) at any site were registered in Pediatric Oncology Group study 7834; 98 were eligible and evaluable. In addition to radiotherapy administered to sites of local relapse, induction consisted of vincristine, doxorubicin, and prednisone (VAP) chemotherapy. Continuation therapy consisted of triple-drug intrathecal therapy and regimens of 6-thioguanine and cytarabine alternating with vincristine, prednisone, cyclophosphamide, and cytarabine. Randomization in continuation was between VAP pulses or no pulse, regardless of the site of relapse. This report provides long-term follow-up of these patients. Thirty-two of 39 children with bone marrow involvement achieved a complete response (CR). Only one of these is alive in an unmaintained remission, a child who did not have an initial CR. Thirty-four of 36 evaluable children with central nervous system involvement as the site of relapse achieved CR. Of these ten are alive; eight are in continuing CR. Nineteen of 20 boys with testicular relapse achieved CR. Of these, 14 are still alive and not receiving therapy, although only one half received treatment in compliance with the protocol described. These results illustrate the possibility of cure of patients who have relapsed with ALL when it is (1) confined to a meningeal or gonadal site and (2) treated vigorously with radiotherapy and a new regimen of systemic chemotherapy. The results reconfirm the need to prevent an initial relapse at any site.

Antineoplastic Combined Chemotherapy Protocols↗

Two-color hybridization with high complexity chromosome-specific probes and a degenerate alpha satellite probe DNA allows unambiguous discrimination between symmetrical and asymmetrical translocations.

This report describes a fluorescence in situ hybridization approach to chromosome staining that facilitates detection of structural aberrations and allows discrimination between dicentric chromosomes and symmetrically translocated chromosomes. In this approach, selected whole chromosomes are stained in one color by hybridization with composite probes whose elements have DNA sequence homology along the length of the target chromosomes. In addition, all chromosomes are counterstained with a DNA specific dye so that structural aberrations between target and non-target chromosomes are clearly visible. Discrimination between dicentric chromosomes and symmetrical translocations is accomplished by hybridization with a second probe that is homologous to DNA sequences found in the centromeric region of all chromosomes. The centromeric marker is visualized in a different color, so that the number of centromeres per aberrant chromosome can be rapidly determined in the microscope by changing excitation and fluorescence filters.

Base Sequence↗

The male-derived genome after sperm-egg fusion: spatial distribution of chromosomal DNA and paternal-maternal genomic association.

After fusion with an egg, the haploid genome of a mammalian sperm expands from a volume of a few cubic microns to a volume of several thousand cubic microns in a fully developed zygote pronucleus. Using fluorescent in situ hybridization we studied two aspects of the chromatin organization of the sperm-derived genome during this process in a model system involving fusion of human sperm with hamster eggs. We found that (a) from the beginning of sperm head decondensation to early pronuclear stages, the hybridization signal of a probe targeted to the satellite III heterochromatin of chromosome 1 appeared as an irregularly shaped domain. In fully developed pronuclei, the signal became a fiber as much as 20-fold more extended compared with interphase somatic nuclei. The signal appeared as a string of non-uniformly distributed "beads" with interspersed gaps. A similar spatial distribution and appearance recurred after the first cleavage division. (b) Male- and female-derived genomes assembled non-randomly on the first mitotic spindle, and continued to be sequestered from each other in the nuclei of two-cell stages.

Animals↗

Construction and characterization of plasmid libraries enriched in sequences from single human chromosomes.

Plasmid libraries enriched in sequences from single chromosome types have been constructed for all human chromosomes. This was accomplished by transferring inserts from the Charon 21A phage libraries constructed by the National Laboratory Gene Library Project into Bluescribe plasmids. Insert material freed by complete digestion of the phage libraries with HindIII or EcoRI was cloned into the corresponding sites in Bluescribe plasmids. The sizes of the Bluescribe library inserts determined by gel electrophoresis range from near 0 to approximately 6 kb. Fluorescence in situ hybridization (FISH) with the plasmid libraries showed that all hybridize along both arms of the expected (target) chromosome type with varying intensity. However, the plasmid libraries for chromosomes 1, 4, 9, 11, 16, 18, and 20 hybridize weakly or not at all near the centromeres of the target chromosome types. The libraries for chromosomes 13, 14, 15, 21, and 22 cross-hybridize near the centromeres of all members of this group and hybridize weakly to the short arms of the target chromosomes. FISH with each library allows specific staining of the target chromosome type in metaphase spreads. The signals resulting from FISH with libraries for chromosomes 1, 4, 8, 9, 13, 14, 17, 18, 21, and Y are sufficiently intense to permit analysis in interphase nuclei. Examples of the use of these libraries for translocation detection, marker chromosome characterization, and interphase aneuploidy analysis are presented.

Chromosome Aberrations↗

Clinical applications of fluorescence in situ hybridization.

We review here the application of fluorescence in situ hybridization with chromosome-specific probes to chromosome classification and to detection of changes in chromosome number or structure associated with genetic disease. Information is presented on probe types that are available for disease detection. We discuss the application of these probes to detection of numerical aberrations important for prenatal diagnosis and to detection and characterization of numerical and structural aberrations in metaphase spreads and in interphase nuclei to facilitate tumor diagnosis.

Chromosome Aberrations↗

Molecular cytometry applied to detection and characterization of disease-linked chromosome aberrations.

Flow karyotyping and FISH with chromosome-specific or disease locus-specific probes are powerful adjuncts to conventional cytogenetic analysis. Flow karyotyping is well suited to quantitative analysis of the DNA content changes that occur during structural rearrangement. FISH with probes for repeated sequences allows ready detection of aneuploidy in interphase cells. FISH with whole-chromosome composite probes to metaphase spreads facilitates detection of subtle structural changes and allows detection of structural aberrations that occur at frequencies as low as 10(-3). FISH with locus-specific probes facilitates diagnosis of specific genetic diseases, may allow phenotype-genotype correlation on a cell by cell basis and will permit sensitive detection of residual disease.

Chromosome Aberrations↗

The use of fluorescence in situ hybridisation combined with premature chromosome condensation for the identification of chromosome damage.

The technique of fusing mitotic cells to interphase cells, thereby producing condensation of the chromosomes of the interphase cell (so-called 'premature chromosome condensation' or PCC), has allowed detection of the initial number of chromosome breaks and their repair following ionising radiation. However, the difficulty and tedium of scoring all the chromosome fragments, as well as the inability to readily detect exchange aberrations, has limited the use of PCC. We describe here the use of the recently developed technique of fluorescence in situ hybridisation with whole chromosome libraries to stain individual human chromosomes (also called 'chromosome painting') with the PCC's and show that this overcomes most of the limitations with the analysis of PCC's. First, by focusing on a single chromosome, scoring of breaks in the target chromosome is easy and rapid and greatly expands the radiation dose range over which the PCC technique can be used. Second, it allows the easy recognition of exchange type aberrations. A number of new applications of this technology, such as predicting the radiosensitivity of human tumours in situ, are feasible.

Cell Line↗