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- Hoebeeck, J, et al.
(författare)
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The von Hippel-Lindau tumor suppressor gene expression level has prognostic value in neuroblastoma
- 2006
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 119:3, s. 624-629
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Tidskriftsartikel (refereegranskat)abstract
- Deletions of the short arm of chromosome 3 are often observed in a specific subset of aggressive neuroblastomas (NBs) with loss of distal 11q and without MYCN amplification. The critical deleted region encompasses the locus of the von Hippel-Lindau gene (VHL, 3p25). Constitutional loss of function mutations in the VHL gene are responsible for the VHL syndrome, a dominantly inherited familial cancer syndrome predisposing to a variety of neoplasms, including pheochromocytoma. Pheochromocytomas are, like NB, derived from neural crest cells, but, unlike NB, consist of more mature chromaffin cells instead of immature neuroblasts. Further arguments for a putative role of VHL in NB are its function as oxygen sensitizer and the reported relation between hypoxia and dedifferentiation of NB cells, leading to a more aggressive phenotype. To test the possible involvement of VHL in NB, we did mRNA expression analysis and sought evidence for VHL gene inactivation. Although no evidence for a classic tumor suppressor role for VHL in NB could be obtained, a strong correlation was observed between reduced levels of VHL mRNA and low patient survival probability (p = 0.013). Furthermore, VHL appears to have predictive power in NTRK1 (TRKA) positive tumor samples with presumed favorable prognosis, which makes it a potentially valuable marker for more accurate risk assessment in this subgroup of patients. The significance of the reduced VHL expression levels in relation to NB tumor biology remains unexplained, as functional analysis demonstrated no clear effect of the reduction in VHL mRNA expression on protein stability of its downstream target hypoxia-inducible factor alpha. (c) 2006 Wiley-Liss, Inc.
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- De Preter, K, et al.
(författare)
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Positional and functional mapping of a neuroblastoma differentiation gene on chromosome 11
- 2005
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Background: Loss of chromosome 11q defines a subset of high-stage aggressive neuroblastomas. Deletions are typically large and mapping efforts have thus far not lead to a well defined consensus region, which hampers the identification of positional candidate tumour suppressor genes. In a previous study, functional evidence for a neuroblastoma suppressor gene on chromosome 11 was obtained through microcell mediated chromosome transfer, indicated by differentiation of neuroblastoma cells with loss of distal 11q upon introduction of chromosome 11. Interestingly, some of these microcell hybrid clones were shown to harbour deletions in the transferred chromosome 11. We decided to further exploit this model system as a means to identify candidate tumour suppressor or differentiation genes located on chromosome 11. Results: In a first step, we performed high-resolution arrayCGH DNA copy-number analysis in order to evaluate the chromosome 11 status in the hybrids. Several deletions in both parental and transferred chromosomes in the investigated microcell hybrids were observed. Subsequent correlation of these deletion events with the observed morphological changes lead to the delineation of three putative regions on chromosome 11: 11q25, 11p13-> 11p15.1 and 11p15.3, that may harbour the responsible differentiation gene. Conclusion: Using an available model system, we were able to put forward some candidate regions that may be involved in neuroblastoma. Additional studies will be required to clarify the putative role of the genes located in these chromosomal segments in the observed differentiation phenotype specifically or in neuroblastoma pathogenesis in general.
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- Mestdagh, P., et al.
(författare)
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An integrative genomics screen uncovers ncRNA T-UCR functions in neuroblastoma tumours
- 2010
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 1476-5594 .- 0950-9232. ; 29:24, s. 3583-3592
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Tidskriftsartikel (refereegranskat)abstract
- Different classes of non-coding RNAs, including microRNAs, have recently been implicated in the process of tumourigenesis. In this study, we examined the expression and putative functions of a novel class of non-coding RNAs known as transcribed ultraconserved regions (T-UCRs) in neuroblastoma. Genome-wide expression pro. ling revealed correlations between specific T-UCR expression levels and important clinicogenetic parameters such as MYCN amplification status. A functional genomics approach based on the integration of multi-level transcriptome data was adapted to gain insights into T-UCR functions. Assignments of T-UCRs to cellular processes such as TP53 response, differentiation and proliferation were verified using various cellular model systems. For the first time, our results de. ne a T-UCR expression landscape in neuroblastoma and suggest widespread T-UCR involvement in diverse cellular processes that are deregulated in the process of tumourigenesis. Oncogene (2010) 29, 3583-3592; doi:10.1038/onc.2010.106; published online 12 April 2010
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| 7. |
- Vandesompele, J, et al.
(författare)
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ID2 expression in neuroblastoma does not correlate to MYCN levels and lacks prognostic value
- 2003
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 1476-5594 .- 0950-9232. ; 22:3, s. 456-460
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Tidskriftsartikel (refereegranskat)abstract
- The MYCN proto-oncogene is frequently amplified in a subgroup of highly aggressive neuroblastomas. The molecular mechanism(s) by which the overexpressed MYCN contributes to an aggressive tumor cell behavior is not well understood. Recently, it was reported that the ID2 gene is a direct target for the MYCN and MYC transcription factors, and that ID2 expression and MYCN amplification correlate positively in neuroblastoma. In addition, ID2 expression was proposed as a negative prognostic parameter. As these results are of potential clinical importance, but not in agreement with our own initial observations, the putative correlation between ID2 and MYC(N) expression in neuroblastoma cell lines and tumors was reinvestigated. We found no correlation between MYCN and ID2 expression in neuroblastoma cell lines or tumor specimens. However, we did find a significant positive correlation between MYC and ID2 expressions in both MYCN-amplified and single-copy tumor specimens, and in MYCN single-copy cell lines. As previously reported, we also found an inverse correlation between MYC and MYCN expressions. Importantly, we could not confirm the reported prognostic power of ID2-expression in neuroblastoma. These data, obtained in two independent laboratories, challenge the previously proposed ID2-MYCN relation.
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