| 1. |
- Abel, Frida, 1974, et al.
(författare)
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Analyses of apoptotic regulators CASP9 and DFFA at 1P36.2, reveal rare allele variants in human neuroblastoma tumours.
- 2002
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Ingår i: British journal of cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 86:4, s. 596-604
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Tidskriftsartikel (refereegranskat)abstract
- The genes encoding Caspase-9 and DFF45 have both recently been mapped to chromosome region 1p36.2, that is a region alleged to involve one or several tumour suppressor genes in neuroblastoma tumours. This study presents an update contig of the 'Smallest Region of Overlap of deletions' in Scandinavian neuroblastoma tumours and suggests that DFF45 is localized in the region. The genomic organization of the human DFF45 gene, deduced by in-silico comparisons of DNA sequences, is described for the first time in this paper. In the present study 44 primary tumours were screened for mutation by analysis of the genomic sequences of the genes. In two out of the 44 tumours this detected in the DFFA gene one rare allele variant that caused a non-polar to a polar amino acid exchange in a preserved hydrophobic patch of DFF45. One case was hemizygous due to deletion of the more common allele of this polymorphism. Out of 194 normal control alleles only one was found to carry this variant allele, so in respect of it, no healthy control individual out of 97 was homozygous. Moreover, our RT-PCR expression studies showed that DFF45 is preferably expressed in low-stage neuroblastoma tumours and to a lesser degree in high-stage neuroblastomas. We conclude that although coding mutations of Caspase-9 and DFF45 are infrequent in neuroblastoma tumours, our discovery of a rare allele in two neuroblastoma cases should be taken to warrant further studies of the role of DFF45 in neuroblastoma genetics.
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| 2. |
- Ejeskär, Katarina, 1969, et al.
(författare)
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Fine mapping of a tumour suppressor candidate gene region in 1p36.2-3, commonly deleted in neuroblastomas and germ cell tumours.
- 2001
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Ingår i: Medical and pediatric oncology. - 0098-1532 .- 1096-911X. ; 36:1, s. 61-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: A common genetic feature of neuroblastomas, which is also an important prognostic factor, is deletion of chromosome region 1p. The deletion of 1p often involves a deletion of varying size, with a consensus region within the most distal bands 1p36.2-3. The neuroblastoma SRO (shortest region of overlap of (deletions) presented earlier by our group was defined distally by the cluster of loci D1S80/ D1Z2/CDC2L1 and proximally by loci D1S244, i.e., approximately 25 cM. The 1p deletions are, however, not restricted to neuroblastoma tumours. In fact, a large spectrum of tumour types display deletions to varying degrees of 1p. PROCEDURE: We have exploited the possibility of using deletions of other tumour types, preferentially that of germ cell tumours, and combining the deletions with that of the neuroblastoma SRO. Also in germ cell tumours, distal 1p-deletions have been shown to have prognostic significance. RESULTS: We found in our germ cell tumours a SRO ranging from D1S508 to D1S200. Interestingly, this region only partially overlapped (approximately 5 cm) with our neuroblastoma SRO in region D1S508 to D1S244. We have thus focused on analysing this smaller region in the search for genes involved in the genesis of different cancers. We have performed radiation hybrid mapping of a large number of markers, STSs, ESTs, and others known to reside in 1p. We have also initiated the development of a BAC contig of the region. FISH, and fibre-FISH mapping of BACs were also performed. CONCLUSIONS: The data presented here constitute an ongoing work with the aim of identifying and cloning gene(s) important for development of germ cell tumours, neuroblastomas, and possibly other tumours.
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| 3. |
- Ejeskär, Katarina, 1969, et al.
(författare)
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Fine mapping of the human preprocortistatin gene (CORT) to neuroblastoma consensus deletion region 1p36.3-->p36.2, but absence of mutations in primary tumors.
- 2000
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Ingår i: Cytogenetics and cell genetics. - : S. Karger AG. - 0301-0171. ; 89:1-2, s. 62-6
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Tidskriftsartikel (refereegranskat)abstract
- The processed product of the human gene preprocortistatin, the peptide cortistatin-17 (hCST-17), bears a strong structural resemblance to the peptide somatostatin (SST), which has an identical receptor binding domain. CST has affinity to all known SST receptor (SSTR) subtypes. Expression of both SST and its receptors has been shown in previous studies to have biological and clinical significance in neuroblastomas, with a putative role in tumor differentiation and apoptosis in vivo. In this work we have employed radiation hybrid mapping and BAC physical mapping to map the human preprocortistatin gene (CORT) to chromosome region 1p36.3-->p36.2, close to the genetic marker D1S244. D1S244 defines the centromeric border of the smallest region of overlap of deletion in our primary neuroblastoma material. We have also defined the genomic sequence of the gene by BAC sequencing and found that preprocortistatin consists of two exons divided by a 1-kb intron. Two polymorphic sites, neither of which causes amino acid exchange, have been detected in the coding region of the gene. Expression studies showed that preprocortistatin is expressed in neuroblastomas of all different stages, as well as in ganglioneuromas. Through genomic sequencing we made mutation analyses of exonic sequences in 49 primary neuroblastomas of all different stages, but no mutations could be detected.
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| 4. |
- Ejeskär, Katarina, 1969
(författare)
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Genetic alterations in Scandinavian neuroblastoma tumors
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The results presented here derive from our efforts to find genes and chromosomal regions of interest in the formation and progression of the childhood tumor neuroblastoma.Neuroblastoma is the most common extracranial solid tumor of childhood. It is a tumor of the postganglionic sympathetic nervous system, and clinically, the hallmark of neuroblastoma is its heterogeneity.In order to characterize chromosomal regions of interest the methods loss of heterozygozity (LOH) studies using PCR-based polymorphic markers, representational difference analysis (RDA), somatic cell hybrid mapping, fluorescent in situ hybridization (FISH), radiation hybrid mapping and physical mapping by construction of a BAC-contig have been used. For mutation analysis of genes the methods single strand conformation polymorphism (SSCP), heteroduplex (HD) and DNA-sequencing have been used, and the expression studies of candidate genes have been performed using RT-PCR.In the Scandinavian neuroblastoma tumor material we have been able to show that deletions of chromosome arm 3p is the second most common deleted chromosomal region (16%) next to 1p (22%). We could also see a difference in clinical outcome between patients with tumors displaying deletion of the entire chromosome 3 versus the ones with tumors displaying deletions of region 3p only. The ones with 3p-deletion have all died of disease whereas the ones with entire chromosome 3 loss are alive and well. We have also characterized a region on chromosome 1, 1p36, shown, by others and us, to be commonly deleted in neuroblastoma tumors. A critical region of app. 25 cM between genetic markers D1S80 and D1S244 could be defined. We have also by using combined LOH-data from both neuroblastoma and germ cell tumors defined a region of common deletion for both tumor types, this region could be defined by markers D1S508 and D1S244 and is app. 5 cM.Also some 1p36 putative tumor suppressor genes, i.e. CDC2L1, TP73 and CORT, have been fine mapped and tested for expression and mutations in neuroblastomas. No evidence for any of them to be the 1p36 neuroblastoma tumor suppressor gene has however been discovered.
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| 5. |
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| 6. |
- Krona, Cecilia, 1976, et al.
(författare)
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A novel 1p36.2 located gene, APITD1, with tumour-suppressive properties and a putative p53-binding domain, shows low expression in neuroblastoma tumours.
- 2004
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Ingår i: British journal of cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 91:6, s. 1119-30
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Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma is characterised by a lack of TP53 mutations and no other tumour suppressor gene consistently inactivated has yet been identified in this childhood cancer form. Characterisation of a new gene, denoted APITD1, in the neuroblastoma tumour suppressor candidate region in chromosome 1p36.22 reveals that APITD1 contains a predicted TFIID-31 domain, representing the TATA box-binding protein-associated factor, TAF(II)31, which is required for p53-mediated transcription activation. Two different transcripts of this gene were shown to be ubiquitously expressed, one of them with an elevated expression in foetal tissues. Primary neuroblastoma tumours of all different stages showed either very weak or no measurable APITD1 expression, contrary to the level of expression observed in neuroblastoma cell lines. A reduced pattern of expression was also observed in a set of various tumour types. APITD1 was functionally tested by adding APITD1 mRNA to neuroblastoma cells, leading to the cell growth to be reduced up to 90% compared to control cells, suggesting APITD1 to have a role in a cell death pathway. Furthermore, we determined the genomic organisation of APITD1. Automated genomic DNA sequencing of the coding region of the gene as well as the promoter sequence in 44 neuroblastoma tumours did not reveal any loss-of-function mutations, indicating that mutations in APITD1 is not a common abnormality of neuroblastoma tumours. We suggest that low expression of this gene might interfere with the ability for apoptosis through the p53 pathway.
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| 7. |
- Krona, Cecilia, 1976, et al.
(författare)
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Screening for gene mutations in a 500 kb neuroblastoma tumor suppressor candidate region in chromosome 1p; mutation and stage-specific expression in UBE4B/UFD2.
- 2003
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 22:15, s. 2343-51
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Tidskriftsartikel (refereegranskat)abstract
- Deletion of a part of the short arm of chromosome 1 is one of the most common chromosomal rearrangements observed in neuroblastoma (NBL) tumors and it is associated with a poor prognosis. No NBL tumor suppressor gene has yet been identified in the region. Our shortest region of overlap of deletions, ranging from marker D1S80 to D1S244, was shown to partly overlap a 500 kb region that was homozygously deleted in a NBL cell line. We have screened seven genes known to reside in or very close to this overlap consensus region, UBE4B/UFD2, KIF1B, DFFA, PGD, CORT, PEX14, and ICAT, for coding mutations in NBL tumor DNA. A few deviations from the reference sequences were identified; most interestingly being a splice site mutation that was detected in UBE4B/UFD2 in a stage 3 NBL with a fatal outcome. This mutation was neither present in the patients constitutional DNA nor in any of 192 control chromosomes analysed. Also, the expression of UBE4B/UFD2 was markedly diminished in the high-stage/poor-outcome tumors as compared to the low-stage/favorable-outcome tumors. Overall, the number of amino-acid changes in the genes of the region was low, which shows that mutations in these genes are rare events in NBL development. Given the data presented here, UBE4B/UFD2 stands out as the strongest candidate NBL tumor suppressor gene in the region at this stage.
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