651
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Wiesmüller L, Wittinghofer A. Expression of the GTPase activating domain of the neurofibromatosis type 1 (NF1) gene in Escherichia coli and role of the conserved lysine residue. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50003-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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652
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Upadhyaya M, Fryer A, MacMillan J, Broadhead W, Huson SM, Harper PS. Prenatal diagnosis and presymptomatic detection of neurofibromatosis type 1. J Med Genet 1992; 29:180-3. [PMID: 1348093 PMCID: PMC1015893 DOI: 10.1136/jmg.29.3.180] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A two year experience of DNA diagnosis for NF1 is presented. Twenty-three NF1 families have been analysed using 11 closely linked and intragenic markers. Prenatal testing was undertaken for six families; 11 affected subjects and their partners wished to know if they would be informative for future prenatal testing, seven of whom are so far fully informative. Presymptomatic testing was done for six subjects. Despite the availability of a series of closely linked markers, informativeness could not be achieved in all of the families tested.
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Affiliation(s)
- M Upadhyaya
- Institute of Medical Genetics, University Hospital of Wales, Heath Park, Cardiff
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653
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Fink TM, Jenne DE, Lichter P. The human vitronectin (complement S-protein) gene maps to the centromeric region of 17q. Hum Genet 1992; 88:569-72. [PMID: 1372588 DOI: 10.1007/bf00219346] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Vitronectin (complement S-protein, serum-spreading factor, epibolin) is a multifunctional glycoprotein that mediates cell-to-substrate adhesion, inhibits the cytolytic action of the terminal complement cascade in vitro and binds to several serine protease inhibitors of the serpin family, viz. antithrombin III, plasminogen activator inhibitor I (PAI-1) and II (PAI-2), heparin cofactor II and protease nexin. Using high resolution fluorescence in situ hybridization, we mapped the vitronectin gene to the centromeric region of the long arm of chromosome 17 corresponding to 17q11. The location was confirmed by co-hybridization with the centromere-specific alphoid probe p17H8 (D17Z1) and by chromosome banding with 4,6-diamidino-2-phenylindole-dihydrochloride (DAPI). None of the previously mapped genes that are evolutionary related to vitronectin are located on the same chromosome.
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Affiliation(s)
- T M Fink
- Deutsches Krebsforschungszentrum, Heidelberg, Federal Republic of Germany
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654
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Basu TN, Gutmann DH, Fletcher JA, Glover TW, Collins FS, Downward J. Aberrant regulation of ras proteins in malignant tumour cells from type 1 neurofibromatosis patients. Nature 1992; 356:713-5. [PMID: 1570015 DOI: 10.1038/356713a0] [Citation(s) in RCA: 489] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Defects in the NF1 gene have been implicated in the inherited disorder neurofibromatosis type 1, which is characterized by several developmental abnormalities including an increased frequency of benign and malignant tumours of neural crest origin (neurofibromas and neurofibrosarcomas respectively). The NF1 gene encodes a ubiquitous protein homologous to p120GAP, the GTPase-activating protein (GAP) for the products of the ras protooncogenes. When expressed in non-mammalian systems, the region of the NF1 gene homologous to p120GAP produces a protein with GAP-like activity. Here we present evidence that the ras proteins in malignant tumour cell lines from patients with type 1 neurofibromatosis are in a constitutively activated state, as judged by the guanine nucleotide bound to them, and are necessary for cellular proliferation. These cells contain p21ras and p120GAP that are both functionally wild type, but barely any functional NF1 protein. Our results show that the NF1 protein is normally essential for correct negative regulation of ras proteins in the cell, even in the presence of normal p120GAP, and they support the hypothesis that NF1 is a tumour-suppressor gene whose product acts upstream of ras.
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Affiliation(s)
- T N Basu
- Signal Transduction Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London, UK
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655
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DeClue JE, Papageorge AG, Fletcher JA, Diehl SR, Ratner N, Vass WC, Lowy DR. Abnormal regulation of mammalian p21ras contributes to malignant tumor growth in von Recklinghausen (type 1) neurofibromatosis. Cell 1992; 69:265-73. [PMID: 1568246 DOI: 10.1016/0092-8674(92)90407-4] [Citation(s) in RCA: 459] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Tumor cell lines derived from malignant schwannomas removed from patients with neurofibromatosis type 1 (NF1) have been examined for the level of expression of NF1 protein. All three NF1 lines examined expressed lower levels of NF1 protein than control cells, and the level in one line was barely detectable. The tumor lines expressed normal levels of p120GAP and p21ras. Although the p21ras proteins isolated from the tumor cells had normal (nonmutant) biochemical properties in vitro, they displayed elevated levels of bound GTP in vivo. The level of total cellular GAP-like activity was reduced in extracts from the tumor line that expresses very little NF1 protein. Introduction of the catalytic region of GAP into this line resulted in morphological reversion and lower in vivo GTP binding by endogenous p21ras. These data implicate NF1 protein as a tumor suppressor gene product that negatively regulates p21ras and define a "positive" growth role for ras activity in NF1 malignancies.
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Affiliation(s)
- J E DeClue
- Laboratory of Cellular Oncology, National Cancer Institute, Bethesda, Maryland 20892
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656
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Li Y, Bollag G, Clark R, Stevens J, Conroy L, Fults D, Ward K, Friedman E, Samowitz W, Robertson M. Somatic mutations in the neurofibromatosis 1 gene in human tumors. Cell 1992; 69:275-81. [PMID: 1568247 DOI: 10.1016/0092-8674(92)90408-5] [Citation(s) in RCA: 285] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The neurofibromatosis 1 (NF1) gene product, neurofibromin, contains a GTPase-activating protein (GAP)-related domain, or NF1 GRD, that is able to down-regulate p21ras by stimulating its intrinsic GTPase. Since p21ras.GTP is a major regulator of growth and differentiation, mutant neurofibromins resulting from somatic mutations in the NF1 gene might interfere with ras signaling pathways and contribute to the development of tumors. We describe an amino acid substitution in the NF1 GRD, altering Lys-1423, that has occurred in three tumor types: colon adenocarcinoma, myelodysplastic syndrome, and anaplastic astrocytoma, and in one family with neurofibromatosis 1. The GAP activity of the mutant NF1 GRD is 200- to 400-fold lower than that of wild type, whereas binding affinity is unaffected. Thus, germline mutations in NF1 that cause neurofibromatosis 1 can also occur in somatic cells and contribute to the development of sporadic tumors, including tumors not associated with neurofibromatosis 1.
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Affiliation(s)
- Y Li
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City 84112
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657
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Loh WE, Scrable HJ, Livanos E, Arboleda MJ, Cavenee WK, Oshimura M, Weissman BE. Human chromosome 11 contains two different growth suppressor genes for embryonal rhabdomyosarcoma. Proc Natl Acad Sci U S A 1992; 89:1755-9. [PMID: 1347425 PMCID: PMC48531 DOI: 10.1073/pnas.89.5.1755] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The identification of acquired homozygosity in human cancers implies locations of tumor suppressor genes without providing functional evidence. The localization of a defect in embryonal rhabdomyosarcomas to chromosomal region 11p15 provides one such example. In this report, we show that transfer of a normal human chromosome 11 into an embryonal rhabdomyosarcoma cell line elicited a dramatic loss of the proliferative capacity of the transferrants. Indeed, the majority of the viable microcell hybrids had either eliminated genetic information on the short arm of the transferred chromosome 11 or increased the copy number of the rhabdomyosarcoma-derived chromosomes 11. Cells that possessed only the long arm of chromosome 11 also demonstrated a decreased growth rate. In contrast, all microcell hybrids retained the ability to form tumors upon inoculation into animals. These functional data support molecular studies indicating loss of genetic information on chromosome 11p15 during the development of embryonal rhabdomyosarcoma. In addition, our studies demonstrate the existence of a second gene on the long arm, previously unrecognized by molecular analyses, which negatively regulates the growth of embryonal rhabdomyosarcoma cell lines.
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Affiliation(s)
- W E Loh
- Division of Hematology/Oncology, Childrens Hospital of Los Angeles, CA 90027
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658
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Flaherty L, Messer A, Russell LB, Rinchik EM. Chlorambucil-induced mutations in mice recovered in homozygotes. Proc Natl Acad Sci U S A 1992; 89:2859-63. [PMID: 1557392 PMCID: PMC48762 DOI: 10.1073/pnas.89.7.2859] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Chlorambucil induced a number of recessive visible mutations in the mouse. Induction of these mutations was studied in two mating schemes, each designed to recover mutations after two intercrosses. In scheme 1, 10 mutations were detected in 82 mice; in scheme 2, 1 mutation was detected in 19 mice. We have estimated that the proportion of gametes carrying a recessive visible mutation may be as high as 25% after a dose of 10 mg of chlorambucil per kg to early spermatids. Seven of these mutations caused morphologically distinct abnormalities, including (i) a cerebellar abnormality similar to that expressed in homozygotes for the reeler (rl) mutation; (ii) open eyelids at birth; (iii) a rostral head hemangioma; (iv) abnormally small spleens, anemia, and umbilical hemorrhages; (v) immobility at birth; (vi) polycystic kidneys; and (vii) a circling behavior. Four additional mutations resulted in growth retardation and a runting syndrome. Because, in earlier studies, all molecularly characterized mutations induced by chlorambucil in poststem cells have proved to be deletions, these recessive visible mutations are probably deletions as well. These mutations may be useful in isolating and characterizing the genes responsible for the observed phenotypes.
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Affiliation(s)
- L Flaherty
- Molecular Genetics Program, Wadsworth Center for Laboratories and Research, Albany, NY 12201
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659
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Walker C, Goldsworthy TL, Wolf DC, Everitt J. Predisposition to renal cell carcinoma due to alteration of a cancer susceptibility gene. Science 1992; 255:1693-5. [PMID: 1553556 DOI: 10.1126/science.1553556] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A single germ line gene mutation at a tumor susceptibility locus in a rodent model of hereditary human renal cancer caused a 70-fold increase in susceptibility to chemical carcinogenesis. A carcinogen that targeted both renal epithelial and mesenchymal cells caused an increase in tumors of epithelial origin in susceptible animals; the number of carcinogen-induced mesenchymal tumors was unaffected by the presence of the mutation at the susceptibility locus. Thus, this mutation defines a genetic locus for susceptibility to carcinogen-induced tumors and modulation of carcinogen susceptibility by this locus exhibits cell-type specificity.
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Affiliation(s)
- C Walker
- Chemical Industry Institute of Toxicology, Research Triangle Park, NC 27709
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660
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Segal G, Sarfatti M, Schaffer MA, Ori N, Zamir D, Fluhr R. Correlation of genetic and physical structure in the region surrounding the I2 Fusarium oxysporum resistance locus in tomato. ACTA ACUST UNITED AC 1992; 231:179-85. [PMID: 1346546 DOI: 10.1007/bf00279789] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The dominant gene I2 confers on tomato (Lycopersicon esculentum) resistance against the fungus Fusarium oxysporum f. sp. lycopersici race 2. A restriction fragment length polymorphism (RFLP) marker, TG105, has recently been found to be tightly linked to I2. The potential for cloning this gene by a reverse genetics approach prompted us to describe in both genetic and physical detail the region surrounding the I2 locus on chromosome 11. We have analyzed patterns of segregation of RFLP markers on chromosome 11 and Fusarium resistance in 140 F2 plants from a cross between Fusarium-resistant and susceptible parental lines. Marker TG105 mapped 0.4 centiMorgan (CM) from I2. Physical analysis of TG105 and its flanking RFLP markers, TG26 and TG36, by pulsed field gradient gel electrophoresis (PFGE) yielded a restriction map for this region encompassing at least 620 kb of the tomato genome. TG105 and TG26 hybridized to the same 175 kb MluI-NruI restriction fragment. We have therefore linked two genetically distinct RFLP markers. Based on the 4.1 cM distance between them, we have assigned a mean value of 43 kb for each cM recombination distance in the vicinity of I2. This local ratio between physical and genetic distances is more than 10-fold below the average for the tomato genome. It should therefore be possible to clone I2 by chromosome walking from TG105.
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Affiliation(s)
- G Segal
- Department of Plant Genetics, Weizmann Institute of Science, Rehovot, Israel
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661
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Abstract
The proteins encoded by the ras proto-oncogenes play critical roles in normal cellular growth, differentiation and development in addition to their potential for malignant transformation. Several proteins that are involved in the control of the activity of p21ras have now been characterised. p120GAP stimulates the GTPase activity of p21ras and hence acts as a negative regulator of ras proteins. It may be controlled by tyrosine phosphorylation or association with tyrosine phosphorylated proteins. The neurofibromatosis type 1 (NF 1) gene also encodes a potential GTPase activating protein which is likely to be subject to a different control mechanism. Guanosine nucleotide exchange factors for p21ras have now been identified: these may be positive regulators of ras protein function. It appears that p21ras is subject to rapid regulation by several distinct mechanisms which are likely to vary in different cell types; the ras proteins are thereby able to act as very sensitive cellular monitors of the extracellular environment.
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Affiliation(s)
- J Downward
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London, UK
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662
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Daston MM, Scrable H, Nordlund M, Sturbaum AK, Nissen LM, Ratner N. The protein product of the neurofibromatosis type 1 gene is expressed at highest abundance in neurons, Schwann cells, and oligodendrocytes. Neuron 1992; 8:415-28. [PMID: 1550670 DOI: 10.1016/0896-6273(92)90270-n] [Citation(s) in RCA: 228] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
von Recklinghausen's neurofibromatosis (NF1) is a common inherited human disease. The events leading to patient symptoms from inheritance of a defective NF1 gene are unknown. Since knowledge of the distribution of the normal NF1 gene product should improve understanding of the pathogenesis of the disease, we raised antibodies against peptides coded by portions of the recently cloned human NF1 cDNA. These antibodies specifically recognize a 220 kd protein (neurofibromin) in both human and rat spinal cord. Neurofibromin is most abundant in the nervous system. Immunostaining of tissue sections indicates that neurons, oligodendrocytes, and nonmyelinating Schwann cells contain neurofibromin while astrocytes and myelinating Schwann cells do not. These results suggest a function for neurofibromin in the normal nervous system. Some NF1 disease manifestations, such as Schwann cell tumors and learning disabilities, may result from abnormalities in the cells that express neurofibromin.
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Affiliation(s)
- M M Daston
- Department of Anatomy and Cell Biology, University of Cincinnati College of Medicine, Ohio 45267-0521
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663
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Hromas R, Zon L, Friedman AD. Hematopoietic transcription regulators and the origins of leukemia. Crit Rev Oncol Hematol 1992; 12:167-90. [PMID: 1590941 DOI: 10.1016/1040-8428(92)90088-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- R Hromas
- Walter Oncology Center, Indiana University Medical Center, Indianapolis 46202
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664
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Abstract
The discovery and characterization of growth regulatory genes, in the form of oncogenes, and their counterparts, tumor suppressor (TS) or antioncogenes, has vastly expanded the basic understanding of tumorigenesis. Human solid tumors, such as colorectal cancer, for which the molecular genetics have been most clearly defined, display progressive evolution from cellular dysplasia to anaplasia and metastasis through the stepwise accumulation of genetic defects, involving the regulation and expression of both oncogenes and TS genes. The study of basic genetic abnormalities in melanoma and the identification of the most fundamental of these is critical both to the understanding of abnormal melanocyte proliferation and its potential pharmacologic or immunologic regulation, and also to the identification and screening of patients at high risk for the development of melanoma. The search for such genetic abnormalities has included an analysis of melanomas for defects in known characterized oncogenes and TS genes, and, more importantly, the use of families with hereditary melanoma (HM) and dysplastic nevi in an endeavor to find the melanoma gene. The importance of HM is fundamental, since in the case of other hereditary cancer syndromes for which the genetic basis has been identified, the same or similar genetic abnormalities underlie sporadic tumors of the same tissue type. Thus HM is likely to be the major signpost to the melanomagenic defect.
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Affiliation(s)
- R F Kefford
- Department of Medical Oncology, University of Sydney, Westmead Centre, New South Wales, Australia
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665
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Downward J. Regulation of p21ras by GTPase activating proteins and guanine nucleotide exchange proteins. Curr Opin Genet Dev 1992; 2:13-8. [PMID: 1633420 DOI: 10.1016/s0959-437x(05)80315-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ras proteins play a critical role in controlling normal cellular growth and, when activated by mutation, in causing malignant transformation. Regulation of p21ras is achieved by GTPase activating proteins, which control the rate of hydrolysis of GTP to GDP, and also by GDP dissociation stimulators, which catalyze the exchange of guanine nucleotides. Several such proteins have now been identified and their control mechanisms characterized.
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Affiliation(s)
- J Downward
- Imperial Cancer Research Fund, London, UK
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666
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Riccardi VM. Type 1 neurofibromatosis and the pediatric patient. CURRENT PROBLEMS IN PEDIATRICS 1992; 22:66-106; discussion 107. [PMID: 1576827 DOI: 10.1016/0045-9380(92)90053-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- V M Riccardi
- Neurofibromatosis Institute, Pasadena, California
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667
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Tokino T, Imai T, Tanigami A, Takiguchi S, Nakamura Y. Physical mapping of a 950-kb region surrounding a locus (D10S102) tightly linked to the MEN2A gene. Genomics 1992; 12:394-400. [PMID: 1346780 DOI: 10.1016/0888-7543(92)90390-e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We have constructed a long-range contig of cosmid and YAC clones around D10S102, a locus that is tightly linked to the gene responsible for multiple endocrine neoplasia type 2A (MEN2A). With D10S102 as a starting point, a 360-kb cosmid contig was constructed by bidirectional genomic walking, and at least six fragments from these cosmids showed high sequence homology to other species. Five YAC clones were also isolated at the D10S102 locus, and they formed a contig covering 950 kb of genomic DNA. Furthermore, we obtained six RFLP systems from the contig, which will serve as new resources for fine-scale genetic linkage mapping of the MEN2A locus.
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Affiliation(s)
- T Tokino
- Division of Biochemistry, Cancer Institute, Tokyo, Japan
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668
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Abstract
The identification of several genes associated with inherited cancer syndromes has opened a door to understanding mechanisms of carcinogenesis in common, non-inherited forms of cancer. Each of these genes appears to play a role in the control of cell growth and differentiation.
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Affiliation(s)
- R White
- Howard Hughes Medical Institute, Salt Lake City, Utah
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669
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670
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Affiliation(s)
- L Stubbs
- Biology Division, Oak Ridge National Laboratory, Tennessee 37831
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671
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Martin-Gallardo A, Marchuk DA, Gocayne J, Kerlavage AR, McCombie WR, Venter JC, Collins FS, Wallace MR. Sequencing and analysis of genomic fragments from the NF1 locus. DNA SEQUENCE : THE JOURNAL OF DNA SEQUENCING AND MAPPING 1992; 3:237-43. [PMID: 1338369 DOI: 10.3109/10425179209034023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The sequence of five non-contiguous genomic fragments encompassing 14.4 kilobases from the NF1 locus have been determined by fluorescence-based automated DNA sequence analysis. These fragments included one kilobase of the NF1 coding region, which resulted in the identification of the intron/exon boundaries of five exons. Based on these sequences, five new NF1 exon-PCR assays have been developed, that could be useful for detecting new NF1 mutations. The genomic sequences were analyzed for the presence of Alu repetitive elements and their classification is described. This analysis may provide some insight into the characterization of genetic rearrangements resulting in disruption of the NF1 gene.
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Affiliation(s)
- A Martin-Gallardo
- Receptor Biochemistry and Molecular Biology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892
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672
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Walker C, Everitt J, Barrett JC. Possible cellular and molecular mechanisms for asbestos carcinogenicity. Am J Ind Med 1992; 21:253-73. [PMID: 1536158 DOI: 10.1002/ajim.4700210214] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Asbestos fibers may exert their carcinogenic effects on mesothelial cells and bronchial epithelial cells by direct and indirect mechanisms. Direct effects can occur following the physical interaction of fibers with target cells or by the generation of free radicals from the fiber surface; indirect effects, following the interaction of fibers with inflammatory cells can result in the production of cellular mediators such as cytokines and various reactive oxygen species. As a result, target cells may be induced to proliferate and/or sustain genetic alterations, which lead to tumor development.
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Affiliation(s)
- C Walker
- Chemical Industry Institute for Toxicology, Research Triangle Park, North Carolina 27709
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673
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Abstract
Recombinant inbred (RI) strains of mice and the closely related recombinant congenic strains offer considerable promise for identifying and characterizing genes causally associated with many different diseases. Loci associated with diseases such as heart disease, autoimmune disease and leukemia have already been identified through the use of these unique strains.
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Affiliation(s)
- M J Justice
- Mammalian Genetics Laboratory, NCI-Frederick Cancer Research and Development Center, MD 21702
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674
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Evans GA, McElligott DL. Physical mapping of human chromosomes. GENETIC ENGINEERING 1992; 14:269-78. [PMID: 1368280 DOI: 10.1007/978-1-4615-3424-2_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Affiliation(s)
- G A Evans
- Molecular Genetics Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037
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675
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Affiliation(s)
- C S Cooper
- Molecular Carcinogenesis Section, Institute of Cancer Research, Haddow Laboratories, Belmont, Sutton, Surrey, United Kingdom
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676
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Roses A, Pericak-Vance M, Alberts M, Saunders A, Taylor H, Gilbert J, Schwartzbach C, Peacock M, Fink J, Bhasin R, Goldgaber D. Locus Heterogeneity of Alzheimer’s Disease. RESEARCH AND PERSPECTIVES IN ALZHEIMER’S DISEASE 1992. [DOI: 10.1007/978-3-642-46776-9_12] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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677
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Weiming X, Yu Q, Lizhi L, Ponder M, Wallace M, Gangfeng X, Ponder B. Molecular analysis of neurofibromatosis type 1 mutations. Hum Mutat 1992; 1:474-7. [PMID: 1301957 DOI: 10.1002/humu.1380010604] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have examined a panel of 115 unrelated NF1 individuals for mutation in the 3' region of the NF1 gene, using Southern blotting and polymerase chain reaction amplification of exons followed by single-strand conformation polymorphism (SSCP) analysis. We found only 2 unequivocal mutations: a 571 bp deletion which removed exon 6 and resulted in a frameshift in exon 7, and a 2 bp deletion in exon 1. A third sequence variation detected by SSCP was predicted to cause a lysine-arginine substitution in exon 6. This is a conservative change, and since the affected individual is a new mutation whose parents are not available, we cannot be sure of its biological significance. We detected mutations in at most 3% of individuals, from an analysis which covered 17% of the coding sequence by SSCP and a larger region by Southern blotting. This relative failure to detect mutations accords with the experience of others. Even allowing for the incomplete sensitivity of the methods used, the results suggest that the majority of NF1 mutations lie elsewhere in the coding sequence or outside it.
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Affiliation(s)
- X Weiming
- Department of Pathology, University of Cambridge, UK
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678
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Suzuki Y, Suzuki H, Kayama T, Yoshimoto T, Shibahara S. Brain tumors predominantly express the neurofibromatosis type 1 gene transcripts containing the 63 base insert in the region coding for GTPase activating protein-related domain. Biochem Biophys Res Commun 1991; 181:955-61. [PMID: 1662505 DOI: 10.1016/0006-291x(91)92029-j] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant neurocutaneous disorder. A part of the gene for NF1 was cloned and its deduced protein has a domain functionally related to mammalian ras GTP-ase-activating protein (GAP). Human tissues examined express two types of NF1 mRNAs: an originally identified species of NF1 mRNA (type I) and another one containing the 63 base insert in the region coding for GAP-related domain (type II). However relative levels of both mRNAs seem to change under certain conditions. Human brain expresses type I mRNA predominantly, while type II is preferentially expressed in most primary brain tumors (13/16 tumors analyzed). We suggest that higher levels of type II mRNA may be related to the genesis of brain tumors.
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Affiliation(s)
- Y Suzuki
- Department of Applied Physiology and Molecular Biology, Tohoku University School of Medicine, Miyagi, Japan
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679
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Watkins WS, O'Connell P, Stevens J, Culver M, Ewart A, Jorde LB. A BglII RFLP near the human neurofibromatosis type 1 (NF1) gene. Nucleic Acids Res 1991; 19:6662. [PMID: 1684425 PMCID: PMC329267 DOI: 10.1093/nar/19.23.6662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- W S Watkins
- Department of Human Genetics, University of Utah School of Medicine, Salt Lake City 84112
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680
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Affiliation(s)
- H Haubruck
- Department of Molecular Biology, Cetus Corporation, Emeryville, CA 94608
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681
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682
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Janson M, Larsson C, Werelius B, Jones C, Glaser T, Nakamura Y, Jones CP, Nordenskjöld M. Detailed physical map of human chromosomal region 11q12-13 shows high meiotic recombination rate around the MEN1 locus. Proc Natl Acad Sci U S A 1991; 88:10609-13. [PMID: 1683706 PMCID: PMC52979 DOI: 10.1073/pnas.88.23.10609] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We have constructed a physical map of the region q12-13 on chromosome 11 by combining data generated from a panel of radiation-reduced somatic cell hybrids and pulsed-field gel electrophoresis (PFGE). Twenty different genetic markers have been sublocalized and ordered within this region and a total of 8.0 megabases has been mapped in detail using rare-cutting restriction endonucleases and PFGE. In two instances, the long-range restriction PFGE map spans the total distance between pairs of loci that have been previously mapped by genetic linkage in reference families. Comparison of this physical map with the available linkage map indicates a great variation in the recombination frequency over the region. The recombination rate is higher than expected, particularly for markers flanking the MEN1 region. Thus, for the closest pair of linked markers on the centromeric side, one centimorgan corresponds to approximately 300 kilobases, and for markers on the telomeric side, one centimorgan corresponds to approximately 350-600 kilobases.
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Affiliation(s)
- M Janson
- Department of Clinical Genetics, Karolinska Hospital, Stockholm, Sweden
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683
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Estivill X, Lázaro C, Casals T, Ravella A. Recurrence of a nonsense mutation in the NF1 gene causing classical neurofibromatosis type 1. Hum Genet 1991; 88:185-8. [PMID: 1757093 DOI: 10.1007/bf00206069] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The gene responsible for von Recklinghausen neurofibromatosis (NF1) has recently been identified, and several point mutations and deletions have been described. The availability of intron-exon boundaries of several exons of the NF1 gene facilitates the search for mutations in affected patients. We have analysed 38 patients for mutations in exon 4 of the NF1 gene, and found one patient with a C----T transition at base position 1087 of the cDNA, changing an arginine codon to a stop codon, at amino acid position 365. Sequencing of other members of the family, including both parents, did not show the mutation, confirming that this mutation is responsible for this sporadic NF1 case. As the mutation described here was previously identified in an independent case by others, this case represents a recurrence of this mutation and suggests that codon 365 might be a hot spot for mutations in the NF1 gene. Thus, a specific search for this mutation should be performed when studying NF1 sporadic or familiar cases for genetic analysis.
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Affiliation(s)
- X Estivill
- Molecular Genetics Department, Hospital Duran y Reynals, Barcelona, Spain
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684
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Seizinger BR. Genes associated with tumor suppression and growth control in the human nervous system. Cancer Metastasis Rev 1991; 10:281-7. [PMID: 1786629 DOI: 10.1007/bf00554790] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cancer, the uncontrolled proliferation of a population of somatic cells, is fundamentally a genetic disorder. Although the specific array of genetic changes causing individual tumor types remains largely obscure, the past two decades have witnessed a tremendous increase in our understanding of the specific genes regulating cell differentiation, proliferation, and senescence. There appear to be two distinct fundamental genetic mechanisms of tumorigenesis. One mechanism is associated with the activation of growth-promoting factors such as proto-oncogenes. Alternatively, tumor formation may be induced as the result of the loss or inactivation of genes which normally regulate or suppress cell growth. These genes have been termed 'tumor suppressor' genes or 'anti-oncogenes'. This review focuses on the role of 'tumor suppressor' genes in tumor formation and growth control of the human nervous system.
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Affiliation(s)
- B R Seizinger
- Molecular Neuro-Oncology Laboratory, Massachusetts General Hospital, Charlestown
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685
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Affiliation(s)
- J Downward
- Imperial Cancer Research Fund, Lincoln's Inn Fields, London WC2A 3PX, UK
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686
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Nishi T, Saya H. Neurofibromatosis type 1 (NF1) gene: implication in neuroectodermal differentiation and genesis of brain tumors. Cancer Metastasis Rev 1991; 10:301-10. [PMID: 1786631 DOI: 10.1007/bf00554792] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The gene responsible for neurofibromatosis type 1 (NF1), a common autosomal dominantly inherited disease, has been isolated. A region of NF1 gene product has been demonstrated to share structural and functional similarities with the mammalian GTPase activating protein (GAP) and the yeast IRA proteins. Thus, the NF1 protein is thought to play a role in signal transduction by stimulating the conversion of the Ras protein from a GTP-bound active form to a GDP-bound inactive form. The increased risk of malignant tumors in neuroectodermal tissues of NF1 patients may be caused by disruption of growth and differentiation regulatory functions of the NF1 gene. A second type of the NF1-GAP related domain (NF1-GRD) transcript, which has an extra 21-amino-acid insert in the center of the previously reported first type transcript, has been described. This insert significantly changes the hydrophilicity and secondary structure of the central region of NF1-GRD, therefore, suggesting it also changes its function. Alternative splicing is the most likely mechanism by which these two types of transcripts arise. The NF1-GRD alternative splicing has been shown to be intimately involved in differentiation of neuroectodermal tissues. Aberrant regulation of the alternative splicing may contribute to tumor formation in neuroectodermal tissue.
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Affiliation(s)
- T Nishi
- Department of Neuro-Oncology, University of Texas M.D. Anderson Cancer Center, Houston
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687
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Weber B, Collins C, Kowbel D, Riess O, Hayden MR. Identification of multiple CpG islands and associated conserved sequences in a candidate region for the Huntington disease gene. Genomics 1991; 11:1113-24. [PMID: 1838348 DOI: 10.1016/0888-7543(91)90039-h] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The HD locus has been assigned to 4p16.3 distal to the DNA segment D4S10. However, the precise location of this gene is still unknown. At least three regions, together encompassing more than 3.5 Mb of DNA, can still be considered as candidate regions for the HD gene. Our efforts are directed toward the cloning and the complete characterization of one of these regions. Thus far we have cloned 460 kb of DNA in contiguously overlapping cosmids distal to D4S111 and have developed a detailed long-range restriction map orienting the contig within the terminal region of 4p16.3. We characterized 15 CpG-rich islands defined by tightly clustered rare cutter restriction sites for the enzymes NotI, BssHII, EagI, NruI, and SacII. In addition, we show that the sequences associated with the CpG-rich islands detect cross-species conservation. The detailed genetic analysis of the 460-kb contig provides a framework for the identification of genes, which can be assessed for the characteristics expected for the HD gene.
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Affiliation(s)
- B Weber
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada
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688
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Marchuk DA, Saulino AM, Tavakkol R, Swaroop M, Wallace MR, Andersen LB, Mitchell AL, Gutmann DH, Boguski M, Collins FS. cDNA cloning of the type 1 neurofibromatosis gene: complete sequence of the NF1 gene product. Genomics 1991; 11:931-40. [PMID: 1783401 DOI: 10.1016/0888-7543(91)90017-9] [Citation(s) in RCA: 302] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Von Recklinghausen neurofibromatosis, or type 1 neurofibromatosis (NF1), is a common autosomal dominant disorder characterized by abnormalities in multiple tissues derived from the embryonic neural crest. Portions of the gene have been recently identified by positional cloning, and sequence analysis has shown homology to the GTPase activating protein (GAP) family. In this report we present the results of an extensive cDNA walk resulting in the cloning of the complete coding region of the NF1 transcript. Analysis of the sequences reveals an open reading frame of 2818 amino acids, although alternatively spliced products may code for different protein isoforms. The gene extends for approximately 300 kb on chromosome 17, with its promoter in a CpG-rich island.
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Affiliation(s)
- D A Marchuk
- Department of Human Genetics, University of Michigan Medical Center, Ann Arbor 48109
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689
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Abstract
Cancer may be defined as a progressive series of genetic events that occur in a single clone of cells because of alterations in a limited number of specific genes: the oncogenes and tumor suppressor genes. The association of consistent chromosome aberrations with particular types of cancer has led to the identification of some of these genes and the elucidation of their mechanisms of action. Consistent chromosome aberrations are observed not only in rare tumor types but also in the relatively common lung, colon, and breast cancers. Identification of additional mutated genes through other chromosomal abnormalities will lead to a more complete molecular description of oncogenesis.
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Affiliation(s)
- E Solomon
- Somatic Cell Genetics Laboratory, Imperial Cancer Research Fund, London, United Kingdom
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690
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Abstract
For the past decade, cellular oncogenes have attracted the attention of biologists intent on understanding the molecular origins of cancer. As the present decade unfolds, oncogenes are yielding their place at center stage to a second group of actors, the tumor suppressor genes, which promise to teach us equally important lessons about the molecular mechanisms of cancer pathogenesis.
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Affiliation(s)
- R A Weinberg
- Whitehead Institute for Biomedical Research, Cambridge, MA
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691
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DeClue JE, Cohen BD, Lowy DR. Identification and characterization of the neurofibromatosis type 1 protein product. Proc Natl Acad Sci U S A 1991; 88:9914-8. [PMID: 1946460 PMCID: PMC52837 DOI: 10.1073/pnas.88.22.9914] [Citation(s) in RCA: 143] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The neurofibromatosis type 1 (NF1) gene responsible for von Recklinghausen neurofibromatosis is related to regulators of ras proteins, and a portion of NF1 that is homologous to the ras GTPase-activating protein (GAP) encodes a similar GTPase-stimulating activity. We have raised rabbit antisera to a bacterially synthesized 48-kDa peptide corresponding to the GAP-related domain of NF1 (NF1-GRD). These antisera immunoprecipitated the NF1-GRD peptide, and one of them specifically inhibited the GTPase-stimulating activity of NF1-GRD. The sera specifically detected a 280-kDa protein in lysates of mouse NIH 3T3 and human HeLa cells. This protein corresponds to the NF1 gene product, as shown by several criteria, including partial proteolysis. Subcellular fractionation revealed that while GAP is predominantly cytoplasmic, all of the NF1 was recovered in a pellet (100,000 x g) fraction. NF1 was present in a large molecular mass complex in fibroblast and Schwannoma cell lines and appears to associate with a very large (400-500 kDa) protein in both cell types. The relevance of these findings to cellular regulation of p21ras is discussed.
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Affiliation(s)
- J E DeClue
- Laboratory of Cellular Oncology, National Cancer Institute, Bethesda, MD 20892
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692
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Allanson JE, Upadhyaya M, Watson GH, Partington M, MacKenzie A, Lahey D, MacLeod H, Sarfarazi M, Broadhead W, Harper PS. Watson syndrome: is it a subtype of type 1 neurofibromatosis? J Med Genet 1991; 28:752-6. [PMID: 1770531 PMCID: PMC1017110 DOI: 10.1136/jmg.28.11.752] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Over 20 years ago, Watson described three families with a condition characterised by pulmonary valvular stenosis, café au lait patches, and dull intelligence. Short stature is an additional feature of this autosomal dominant condition. A fourth family with Watson syndrome has since been reported. We have had the opportunity to review members of three of these four families. The clinical phenotype of Watson syndrome has been expanded to include relative macrocephaly and Lisch nodules in the majority of affected subjects, and neurofibromas in one-third of family members. Because the additional clinical findings enhance the similarity between Watson syndrome and neurofibromatosis 1, molecular linkage studies have been performed using probes flanking the NF1 gene on chromosome 17. Probe HHH202 showed the tightest linkage to Watson syndrome with a maximum lod score of 3.59 at phi = 0.0 (95% confidence limits of phi = 0.0-0.15). This suggests either that Watson syndrome and neurofibromatosis 1 are allelic, or that there is a series of contiguous genes for pulmonary stenosis, neurocutaneous anomalies, short stature, and mental retardation on 17q.
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Affiliation(s)
- J E Allanson
- Division of Genetics, Children's Hospital of Eastern Ontario, Canada
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693
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Rodenhiser DI, Coulter-Mackie MB, Jung JH, Singh SM. A genetic study of neurofibromatosis 1 in south-western Ontario. I. Population, familial segregation of phenotype, and molecular linkage. J Med Genet 1991; 28:746-51. [PMID: 1685193 PMCID: PMC1017109 DOI: 10.1136/jmg.28.11.746] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This report is concerned with neurofibromatosis type 1 (NF-1, 17q11.2) in south-western Ontario, an ethnically diverse population derived from multiple immigrations. The population incidence, prevalence, and mutation rates for this disease are similar in most racial groups of this population and are also comparable to earlier reports. NF-1 is one of the most common single gene disorders in this population. The occurrence of the disease is not affected by the birth order or sex of the transmitting parent. The severe manifestation of this disease is statistically related to paternal transmission. Five polymorphic DNA probes (pA1041, pHHH202, pTH1719, NF1, pEW206, pEW207) were evaluated in relation to segregation of NF-1 using appropriate restriction enzymes. The observed heterozygosity was found to be relatively high, ranging from 25% to 55% for all the probes on 17q and flanking the NF-1 gene. We recommend the use of pHHH202/pTH1719 and pEW206 in any linkage analysis for detection of the presence of the NF-1 mutation. For informative families the degree of certainty is as high as 99.5%. Some future modifications may include the use of NF-1 exon specific probes and primers that remain to be evaluated for heterogeneity and heterozygosity among populations.
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Affiliation(s)
- D I Rodenhiser
- Child Health Research Institute, Department of Paediatrics, University of Western Ontario, London, Canada
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694
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Gutmann DH, Wood DL, Collins FS. Identification of the neurofibromatosis type 1 gene product. Proc Natl Acad Sci U S A 1991; 88:9658-62. [PMID: 1946382 PMCID: PMC52777 DOI: 10.1073/pnas.88.21.9658] [Citation(s) in RCA: 208] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The gene for neurofibromatosis type 1 (NF1) was recently identified by positional cloning. The complete cDNA encodes a polypeptide of 2818 amino acids. To study the NF1 gene product, antibodies were raised against both fusion proteins and synthetic peptides. Initial characterization of two anti-peptide antibodies and one fusion-protein antibody demonstrated a specific protein of approximately 250 kDa by both immunoprecipitation and immunoblotting. This protein was found in all tissues and cell lines examined and is detected in human, rat, and mouse tissues. To demonstrate that these antibodies specifically recognize the NF1 protein, additional fusion proteins containing the sequence specific to the synthetic peptide were generated. Both peptide antisera recognize the proper specific fusion proteins so generated. Immunoprecipitates using the peptide antisera were shown to recognize the same protein detected by immunoblotting with either the other peptide antiserum or the fusion-protein antiserum. Immunoblotting using antiserum specific to spatially distinct epitopes conducted on tissue homogenates demonstrated the NF1 protein in all adult tissues. Based on the homology between the NF1 gene product and members of the GTPase-activating protein (GAP) superfamily, the name NF1-GAP-related protein (NF1GRP) is suggested.
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Affiliation(s)
- D H Gutmann
- Department of Internal Medicine, University of Michigan, Ann Arbor 48109-0650
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695
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Rapola J, Järvelä I, Peltonen L. The neuronal ceroid lipofuscinoses: unfolding the genetic defect. PEDIATRIC PATHOLOGY 1991; 11:799-806. [PMID: 1663617 DOI: 10.3109/15513819109065477] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- J Rapola
- Department of Pathology, University of Helsinki, Finland
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696
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Wallace MR, Andersen LB, Saulino AM, Gregory PE, Glover TW, Collins FS. A de novo Alu insertion results in neurofibromatosis type 1. Nature 1991; 353:864-6. [PMID: 1719426 DOI: 10.1038/353864a0] [Citation(s) in RCA: 355] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder with a high mutation rate and variable expression, characterized by neurofibromas, café-au-lait spots, Lisch nodules of the iris, and less frequent features including bone deformities and learning disabilities. The recently cloned NF1 gene encodes a transcript of 13 kilobases from a ubiquitously expressed locus on chromosome 17. Most NF1 patients are expected to have unique mutations, but only a few have so far been characterized, restricting genetic and functional information and the design of DNA diagnostics. We report an unusual NF1 mutation, that of a de novo Alu repetitive element insertion into an intron, which results in deletion of the downstream exon during splicing and consequently shifts the reading frame. This previously undescribed mechanism of mutation indicates that Alu retrotransposition is an ongoing process in the human germ line.
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Affiliation(s)
- M R Wallace
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor 48109-0650
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697
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Yen PH, Tsai SP, Wenger SL, Steele MW, Mohandas TK, Shapiro LJ. X/Y translocations resulting from recombination between homologous sequences on Xp and Yq. Proc Natl Acad Sci U S A 1991; 88:8944-8. [PMID: 1924355 PMCID: PMC52627 DOI: 10.1073/pnas.88.20.8944] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Several regions of sequence homology between the human X and Y chromosomes have been identified. These segments are thought to represent areas of these chromosomes that have engaged in meiotic recombination in relatively recent evolutionary times. Normally, the X and Y chromosomes pair during meiosis and exchange DNA only within the pseudoautosomal region at the distal short arms of both chromosomes. However, it has been suggested that aberrant recombination involving other segments of high homology could be responsible for the production of X/Y translocations. We have studied four X/Y translocation patients using molecular probes detecting homologous sequences on X and Y chromosomes. In one translocation the breakpoints have been isolated and sequenced. The mapping data are consistent with the hypothesis that X/Y translocations arise by homologous recombination. The sequencing data from one translocation demonstrate this directly.
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Affiliation(s)
- P H Yen
- Howard Hughes Medical Institute, University of California, Los Angeles
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698
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Stark M, Assum G, Krone W. A small deletion and an adjacent base exchange in a potential stem-loop region of the neurofibromatosis 1 gene. Hum Genet 1991; 87:685-7. [PMID: 1937470 DOI: 10.1007/bf00201726] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A single-strand conformational polymorphism found in the DNA of a patient with neurofibromatosis 1 (NF1) was shown to be caused by a deletion of a CCACC or CACCT sequence and an adjacent transversion, located about 500 base pairs downstream from the region that codes for a functional domain of the NF1 gene product. This mutation could also be detected in the patient and in his affected daughter by heteroduplex analysis. The deletion removes the proximal half of a small potential stem-loop and interrupts the reading frame in exon 1. A severely truncated protein with a grossly altered carboxy terminus lacking one third of its sequence is expected to be formed from the mutant allele.
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Affiliation(s)
- M Stark
- Abteilung Humangenetik der Universität, Ulm, Federal Republic of Germany
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699
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White R, Viskochil D, O'Connell P. Identification and characterization of the gene for neurofibromatosis type 1. Curr Opin Neurobiol 1991; 1:462-7. [PMID: 1821691 DOI: 10.1016/0959-4388(91)90070-n] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Elucidation of the partial genomic structure and DNA sequence of the gene that is altered in neurofibromatosis type 1, and the discovery of clues to its function, have opened new opportunities not only for understanding this particular disease process but also for clarifying signal pathways involved in cellular growth and differentiation. (This review is an updated and modified version of a review first published in Current Opinion in Genetics and Development 1991, 1:15-19.)
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Affiliation(s)
- R White
- Howard Hughes Medical Institute, Salt Lake City, Utah
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700
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Schroeder WT, Siciliano MJ, Stewart-Galetka SL, Duvic M. The human gene for an epidermal surface antigen (M17S1) is located at 17q11-12. Genomics 1991; 11:481-2. [PMID: 1769667 DOI: 10.1016/0888-7543(91)90166-c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- W T Schroeder
- Department of Dermatology, University of Texas Medical School, Houston 77030
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