Table of Contents
1
UI - 1479598
AU - Evans DG; Huson SM; Donnai D; Neary W; Blair V; Teare D; Newton V;
TI -
Strachan T; Ramsden R; Harris R
A genetic study of type 2 neurofibromatosis in the United Kingdom. I.
Prevalence, mutation rate, fitness, and confirmation of maternal
transmission effect on severity.
SO - J Med Genet 1992 Dec;29(12):841-6
AD - Department of Medical Genetics, St Mary's Hospital, Manchester.
A clinical and genetic study of type 2 neurofibromatosis (NF2) has been
carried out in the United Kingdom. Virtually complete ascertainment of
cases in the north-west of England was achieved and suggests a
population incidence of 1 in 33,000 to 40,000. In the UK as a whole, 150
cases have been identified and been used to study the clinical and
genetic features of NF2. The autosomal dominant inheritance of NF2 was
confirmed, 49% of cases were assessed as representing new mutations, and
the mutation rate was estimated to be 6.5 x 10(-6). Evidence to support
a maternal gene effect was found in that age at onset was 18.17 years in
36 maternally inherited cases and 24.5 in 20 paternally inherited cases
(p = 0.027). The preponderance of maternally inherited cases was also
significant (p = 0.03). Data are presented which suggest that there are
two types of NF2, one with later onset and bilateral vestibular
schwannomas as the only usual feature, and the other with earlier onset
and multiple other tumours. A considerable number of cases did not fall
easily into one or other group and other factors such as maternal effect
on severity and anticipation need to be considered.
2
UI - 11732488
AU - Baser ME; Friedman JM; Evans GR
TI -
Maternal gene effect in neurofibromatosis 2: fact or artefact?
SO - J Med Genet 2001 Nov;38(11):783-4
3
UI - 11719502
AU - Xiao GH; Beeser A; Chernoff J; Testa JR
TI -
p21-activated kinase links Rac/Cdc42 signaling to merlin.
SO - J Biol Chem 2002 Jan 11;277(2):883-6
AD - Human Genetics Program, Fox Chase Cancer Center, Philadelphia,
Pennsylvania 19111, USA.
The neurofibromatosis type 2 tumor suppressor gene, NF2, is mutated in
the germ line of NF2 patients and predisposes affected individuals to
intracranial and spinal tumors. Moreover, somatic mutations of NF2 can
occur in the sporadic counterparts of these neurological tumor types as
well as in certain neoplasms of non-neuroectodermal origin, such as
malignant mesothelioma and melanoma. NF2 encodes a 595-amino acid
protein, merlin, which exhibits significant homology to the
ezrin-radixin-moesin family of proteins. However, the mechanism by which
merlin exerts its tumor suppressor activity is not well understood. In
this investigation, we show that merlin is phosphorylated in response to
expression of activated Rac and activated Cdc42 in mammalian cells.
Furthermore, we demonstrate that merlin phosphorylation is mediated by
p21-activated kinase (Pak), a common downstream target of both Rac and
Cdc42. Both in vivo and in vitro kinase assays demonstrated that Pak can
directly phosphorylate merlin at serine 518, a site that affects merlin
activity and localization. These biochemical investigations provide
insights into the regulation of merlin function and establish a
framework for elucidating tumorigenic mechanisms involved in neoplasms
associated with merlin inactivation.
4
UI - 11418738
AU - Basu S; Sarkar R
TI -
Neurofibromatosis-1 in a family.
SO - Indian Pediatr 2001 Jun;38(6):676-7
AD - Department of Pediatrics, Government Medical College and Hospital,
Sector 32, Chandigarh 160 047, India.
5
UI - 11684412
AU - Sherman LS; Gutmann DH
TI -
Merlin: hanging tumor suppression on the Rac.
SO - Trends Cell Biol 2001 Nov;11(11):442-4
AD - Vontz Center for Molecular Studies, Dept of Cell Biology, Neurobiology
and Anatomy, University of Cincinnati College of Medicine, Cincinnati,
OH, USA.
Cancer can result from any number of abnormalities in the control of
cell-cycle progression, intracellular signaling and transduction of
extracellular cues. Many insights into the crucial events that govern
the regulation of cell growth have derived from studies of the gene
products mutated in inherited cancer syndromes. Recent work on the
neurofibromatosis 2 (NF2) tumor suppressor gene suggests that this
negative growth regulator might function by modulating growth factor and
extracellular matrix (ECM) signals that trigger Rac1-dependent
cytoskeleton-associated processes. In this article, we propose a
molecular model for NF2 protein (merlin) function in the light of these
and related new findings.
6
UI - 11784085
AU - Haines TR; Rodenhiser DI; Ainsworth PJ
TI -
Allele-specific non-CpG methylation of the Nf1 gene during early mouse
development.
SO - Dev Biol 2001 Dec 15;240(2):585-98
AD - London Regional Cancer Centre, Departments of Biochemistry, Child Health
Research Institute, London Health Sciences Centre, Ontario, London, N6C
2V5, Canada.
Recent reports of cytosine methylation occurring at CpA and CpT
dinucleotides in murine ES cells as well as in Drosophila have renewed
interest in methylation at sites other than CpGs. Our examination of the
murine neurofibromatosis type 1 gene by sodium bisulfite genomic
sequencing has revealed non-CpG methylation primarily in the oocyte and
the maternally derived allele of the 2-cell embryo, with markedly lower
levels found in sperm. Non-CpG methylation was not found in later stages
of embryo development or in adult tissue. Our results suggest that
maternal-specific de novo non-CpG methylation has occurred sometime
between ovulation and formation of the 2-cell embryo, while during the
same period the paternally derived allele has undergone site-specific
active demethylation. Our data demonstrate both stage and
parent-of-origin specific changes in methylation patterns within the
neurofibromatosis type 1 coding region-involving cytosines located at
both CpG and non-CpG dinucleotides.
7
UI - 11809679
AU - Whiteside D; McLeod R; Graham G; Steckley JL; Booth K; Somerville MJ;
TI -
Andrew SE
A homozygous germ-line mutation in the human MSH2 gene predisposes to
hematological malignancy and multiple cafe-au-lait spots.
SO - Cancer Res 2002 Jan 15;62(2):359-62
AD - Department of Medical Genetics, University of Alberta, Edmonton,
Alberta, T6G 2H7 Canada.
Individuals with a germ-line mutation in one of the DNA mismatch repair
(MMR) genes are at significant risk for colorectal cancer and other
tumors. Three families have previously been reported with individuals
homozygous for mutations in the MMR gene MLH1 that are predicted to
compromise MMR. These individuals develop hematological malignancies
and/or neurofibromatosis type 1 at an early age. Here, in an individual,
we demonstrate that a homozygous novel mutation in the MMR gene MSH2 is
associated with leukemia and multiple cafe-au-lait spots, a feature of
neurofibromatosis type 1. Because the hematological malignancies
observed in the individuals homozygous for the loss of MMR are
reflective of the lymphomas seen in mice lacking MMR, the mice may
provide a useful model for human neoplasia.
8
UI - 11737695
AU - Dupuis L; Nezarati MM
TI -
Neurofibromatosis type I as a model of autosomal dominant inheritance.
SO - Pediatr Dermatol 2001 Sep-Oct;18(5):445-7
AD - Division of Clinical and Metabolic Genetics, Hospital for Sick Children,
Toronto, Ontario, Canada.
9
UI - 11321371
AU - Bentivegna A; Venturin M; Gervasini C; Corrado L; Larizza L; Riva P
TI -
FISH with locus-specific probes on stretched chromosomes: a useful tool
for genome organization studies.
SO - Chromosome Res 2001;9(2):167-70
AD - Department of Biology and Genetics, Medical Faculty, University of
Milan, Italy.
10
UI - 11779178
AU - Scoles DR; Chen M; Pulst SM
TI -
Effects of Nf2 missense mutations on schwannomin interactions.
SO - Biochem Biophys Res Commun 2002 Jan 11;290(1):366-74
AD - Division of Neurology, Cedars-Sinai Medical Center, 1145E Medical Tower,
8631 West 3rd Street, Los Angeles, CA 90048, USA. scolesd@cshs.org
Most benign brain tumors are associated with loss of the Nf2 gene tumor
suppressor product schwannomin/merlin. Interactions between schwannomin
fragments have given rise to hypotheses of in vivo schwannomin folding
and dimerization. Previously, we showed that schwannomin with missense
mutations L360P, L535P, and Q538P alters interaction with
betaII-spectrin and Hrs. Using yeast two-hybrid tests of interaction, we
now show the effects of 11 Nf2 missense mutations on schwannomin
self-interaction as well as schwannomin interaction with Hrs isoforms 1
and 2, betaII-spectrin, and p110. Missense mutations L46R and K364I
significantly decreased affinity of schwannomin for binding all
interacting proteins. The schwannomin L46R mutation may result in a
complex conformational change that alters folding and denies
betaII-spectrin access to an intact binding site in the C-terminal half
of schwannomin. We show that unique inter- and intramolecular
interactions occur for schwannomin isoform 2, suggesting that this
schwannomin isoform has unique functional properties compared to
schwannomin isoform 1. (c)2002 Elsevier Science.
11
UI - 11788835
AU - Tong J; Hannan F; Zhu Y; Bernards A; Zhong Y
TI -
Neurofibromin regulates G protein-stimulated adenylyl cyclase activity.
SO - Nat Neurosci 2002 Feb;5(2):95-6
AD - Cold Spring Harbor Laboratory, PO Box 100, Cold Spring Harbor, New York
11724, USA.
Neurofibromatosis type 1 (NF1) is a dominant genetic disorder
characterized by multiple benign and malignant nervous system tumors,
and by learning defects in 45% of children with NF1 mutations. Studies
of neurofibromin, the protein encoded by NF1, have focused on its
functions in tumorigenesis and regulation of Ras activity; however,
Drosophila NF1 regulates both Ras and cyclic AMP (cAMP) pathways.
Expression of a human NF1 transgene rescued cAMP-related phenotypes in
NF1 mutant flies (small body size and G protein-stimulated adenylyl
cyclase (AC) activity defects), and neuropeptide- and G
protein-stimulated AC activity were lower in Nf1-/- as compared to
Nf1+/- mouse brains, demonstrating that neurofibromin regulates AC
activity in both mammals and flies.
12
UI - 11789444
AU - Danek A; Wahllander-Danek U; Stenglein-Krapf G; Uttner I
TI -
[Type I neurofibromatosis. A model for the study of molecular principles
of cognition]
SO - Nervenarzt 2001 Dec;72(12):963-7
AD - Neurologische Klinik und Poliklinik, Ludwig-Maximilians-Universitat
Munchen, Klinikum Grosshadern, Marchioninistrasse 15, 81377 Munchen.
Cognitive impairment in neurofibromatosis type I (NF1) has only recently
attracted interest. In addition to previous studies in children, our own
investigation of 20 patients confirms the slightly lowered psychometric
test scores also for adults with NF1. Molecular manipulation of the
neurofibromin gene leads to learning disorders in the mouse model
("cognitive neurogenetics"). It is not just faulty brain development
that underlies these findings: neurofibromin plays a role in signal
transduction cascades that are active during learning and memory
throughout the life span. Thus, it appears possible to cure the
cognitive defects at least in the mouse ("cognitive enhancement"). In
man, an early diagnosis of NF1 is presently essential in order to
provide specific remedial education for children affected by the
learning disorder of neurofibromatosis type I.
The above citations and abstracts reflect those newly added to CANCERLIT for the month and topic listed in the title. The citations have been retrieved from CANCERLIT using a predefined search strategy of indexed subject terms. Although the search strategy has been refined as best as possible, citations may appear that are not directly related to the topic, and occasionally relevant references may be omitted.
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