| 1. |
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| 2. |
- Zander, Cecilia Soussi, et al.
(författare)
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Breast-cancer stromal cells with TP53 mutations
- 2008
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 358:15, s. 1635-1635
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Ali, Muhammad Akhtar
(författare)
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Understanding Cancer Mutations by Genome Editing
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mutational analyses of cancer genomes have identified novel candidate cancer genes with hitherto unknown function in cancer. To enable phenotyping of mutations in such genes, we have developed a scalable technology for gene knock-in and knock-out in human somatic cells based on recombination-mediated construct generation and a computational tool to design gene targeting constructs. Using this technology, we have generated somatic cell knock-outs of the putative cancer genes ZBED6 and DIP2C in human colorectal cancer cells. In ZBED6-/- cells complete loss of functional ZBED6 was validated and loss of ZBED6 induced the expression of IGF2. Whole transcriptome and ChIP-seq analyses revealed relative enrichment of ZBED6 binding sites at upregulated genes as compared to downregulated genes. The functional annotation of differentially expressed genes revealed enrichment of genes related to cell cycle and cell proliferation and the transcriptional modulator ZBED6 affected the cell growth and cell cycle of human colorectal cancer cells. In DIP2C-/-cells, transcriptome sequencing revealed 780 differentially expressed genes as compared to their parental cells including the tumour suppressor gene CDKN2A. The DIP2C regulated genes belonged to several cancer related processes such as angiogenesis, cell structure and motility. The DIP2C-/-cells were enlarged and grew slower than their parental cells. To be able to directly compare the phenotypes of mutant KRAS and BRAF in colorectal cancers, we have introduced a KRASG13D allele in RKO BRAFV600E/-/-/ cells. The expression of the mutant KRAS allele was confirmed and anchorage independent growth was restored in KRASG13D cells. The differentially expressed genes both in BRAF and KRAS mutant cells included ERBB, TGFB and histone modification pathways. Together, the isogenic model systems presented here can provide insights to known and novel cancer pathways and can be used for drug discovery.
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| 4. |
- Carlsson, Jonas, et al.
(författare)
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Investigation and prediction of the severity of p53 mutants using parameters from structural calculations
- 2009
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Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 276:15, s. 4142-4155
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Tidskriftsartikel (refereegranskat)abstract
- A method has been developed to predict the effects of mutations in the p53 cancer suppressor gene. The new method uses novel parameters combined with previously established parameters. The most important parameter is the stability measure of the mutated structure calculated using molecular modelling. For each mutant, a severity score is reported, which can be used for classification into deleterious and nondeleterious. Both structural features and sequence properties are taken into account. The method has a prediction accuracy of 77% on all mutants and 88% on breast cancer mutations affecting WAF1 promoter binding. When compared with earlier methods, using the same dataset, our method clearly performs better. As a result of the severity score calculated for every mutant, valuable knowledge can be gained regarding p53, a protein that is believed to be involved in over 50% of all human cancers.
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| 5. |
- Doffe, Flora, et al.
(författare)
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Identification and functional characterization of new missense SNPs in the coding region of the TP53 gene
- 2021
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Ingår i: Cell Death and Differentiation. - : Springer Science and Business Media LLC. - 1350-9047 .- 1476-5403. ; 28:5, s. 1477-1492
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Tidskriftsartikel (refereegranskat)abstract
- Infrequent and rare genetic variants in the human population vastly outnumber common ones. Although they may contribute significantly to the genetic basis of a disease, these seldom-encountered variants may also be miss-identified as pathogenic if no correct references are available. Somatic and germline TP53 variants are associated with multiple neoplastic diseases, and thus have come to serve as a paradigm for genetic analyses in this setting. We searched 14 independent, globally distributed datasets and recovered TP53 SNPs from 202,767 cancer-free individuals. In our analyses, 19 new missense TP53 SNPs, including five novel variants specific to the Asian population, were recurrently identified in multiple datasets. Using a combination of in silico, functional, structural, and genetic approaches, we showed that none of these variants displayed loss of function compared to the normal TP53 gene. In addition, classification using ACMG criteria suggested that they are all benign. Considered together, our data reveal that the TP53 coding region shows far more polymorphism than previously thought and present high ethnic diversity. They furthermore underline the importance of correctly assessing novel variants in all variant-calling pipelines associated with genetic diagnoses for cancer.
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| 6. |
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| 7. |
- Edlund, Karolina, et al.
(författare)
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Data-driven unbiased curation of the TP53 tumor suppressor gene mutation database and validation by ultradeep sequencing of human tumors
- 2012
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 109:24, s. 9551-9556
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Tidskriftsartikel (refereegranskat)abstract
- Cancer mutation databases are expected to play central roles in personalized medicine by providing targets for drug development and biomarkers to tailor treatments to each patient. The accuracy of reported mutations is a critical issue that is commonly overlooked, which leads to mutation databases that include a sizable number of spurious mutations, either sequencing errors or passenger mutations. Here we report an analysis of the latest version of the TP53 mutation database, including 34,453 mutations. By using several data-driven methods on multiple independent quality criteria, we obtained a quality score for each report contributing to the database. This score can now be used to filter for high-confidence mutations and reports within the database. Sequencing the entire TP53 gene from various types of cancer using next-generation sequencing with ultradeep coverage validated our approach for curation. In summary, 9.7% of all collected studies, mostly comprising numerous tumors with multiple infrequent TP53 mutations, should be excluded when analyzing TP53 mutations. Thus, by combining statistical and experimental analyses, we provide a curated mutation database for TP53 mutations and a framework for mutation database analysis.
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| 8. |
- Lazarian, Gregory, et al.
(författare)
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The Broad Spectrum of TP53 Mutations in CLL : Evidence of Multiclonality and Novel Mutation Hotspots
- 2023
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Ingår i: Human Mutation. - : Hindawi Limited. - 1059-7794 .- 1098-1004. ; 2023
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Tidskriftsartikel (refereegranskat)abstract
- TP53 aberrations are a major predictive factor of resistance to chemoimmunotherapy in chronic lymphocytic leukemia (CLL), and an assessment of them before each line of treatment is required for theranostic stratification. Acquisition of subclonal TP53 abnormalities underlies the evolution of CLL. To better characterize the distribution, combination, and impact of TP53 variants in CLL, 1,056 TP53 variants collected from 683 patients included in a multicenter collaborative study in France were analyzed and compared to UMD_CLL, a dataset built from published articles collectively providing 5,173 TP53 variants detected in 3,808 patients. Our analysis confirmed the presence of several CLL-specific hotspot mutations, including a two-base pair deletion in codon 209 and a missense variant at codon 234, the latter being associated with alkylating treatment. Our analysis also identified a novel CLL-specific variant in the splice acceptor signal of intron 6 leading to the use of a cryptic splice site, similarly utilized by TP53 to generate p53psi, a naturally truncated p53 isoform localized in the mitochondria. Examination of both UMD_CLL and several recently released large-scale genomic analyses of CLL patients confirmed that this splice variant is highly enriched in this disease when compared to other cancer types. Using a TP53-specific single-nucleotide polymorphism, we also confirmed that copy-neutral loss of heterozygosity is frequent in CLL. This event can lead to misinterpretation of TP53 status. Unlike other cancers, CLL displayed a high proportion of patients harboring multiple TP53 variants. Using both in silico analysis and single molecule smart sequencing, we demonstrated the coexistence of distinct subclones harboring mutations on distinct alleles. In summary, our study provides a detailed TP53 mutational architecture in CLL and gives insights into how treatments may shape the genetic landscape of CLL patients.
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| 9. |
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| 10. |
- Matas, Julia, et al.
(författare)
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Colorectal Cancer Is Associated with the Presence of Cancer Driver Mutations in Normal Colon
- 2022
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Ingår i: Cancer Research. - : American Association for Cancer Research (AACR). - 0008-5472 .- 1538-7445. ; 82:8, s. 1492-1502
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Tidskriftsartikel (refereegranskat)abstract
- Although somatic mutations in colorectal cancer are well characterized, little is known about the accumulation of cancer mutations in the normal colon before cancer. Here, we have developed and applied an ultrasensitive, single-molecule mutational test based on CRISPR-DS technology, which enables mutation detection at extremely low frequency (< 0.001) in normal colon from patients with and without colorectal cancer. This testing platform revealed that normal colon from patients with and without colorectal cancer carries mutations in common colorectal cancer genes, but these mutations are more abundant in patients with cancer. Oncogenic KRAS mutations were observed in the normal colon of about one third of patients with colorectal cancer but in none of the patients without colorectal cancer. Patients with colorectal cancer also carried more TP53 mutations than patients without cancer and these mutations were more pathogenic and formed larger clones, especially in patients with early-onset colorectal cancer. Most mutations in the normal colon were different from the driver mutations in tumors, suggesting that the occurrence of independent clones with pathogenic KRAS and TP53 mutations is a common event in the colon of individuals who develop colorectal cancer. These results indicate that somatic evolution contributes to clonal expansions in the normal colon and that this process is enhanced in individuals with cancer, particularly in those with early-onset colorectal cancer. Significance: This work suggests prevalent somatic evolution in the normal colon of patients with colorectal cancer, highlighting the potential of using ultrasensitive gene sequencing to predict disease risk. [GRAPHICS]
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| 11. |
- Ren, Zhi-Ping, et al.
(författare)
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Molecular genetic analysis of p53 intratumoral heterogeneity in human astrocytic brain tumors
- 2007
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Ingår i: Journal of Neuropathology and Experimental Neurology. - : Oxford University Press (OUP). - 0022-3069 .- 1554-6578. ; 66:10, s. 944-954
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Tidskriftsartikel (refereegranskat)abstract
- We investigated genetic heterogeneity of astrocytic gliomas using p53 gene mutations as a marker. Different parts of morphologically heterogeneous astrocytic gliomas were micro-dissected, and direct DNA sequencing of p53 gene exons 5 through 8 was performed. Thirty-five glioma samples and tumor-adjacent normal-appearing brain tissue from I I patients were analyzed. Sixteen different p53 gene mutations were found in 7 patients. We found that some tumors were devoid of p53 gene mutations, whereas other tumors carried I or often several (up to 3) different mutations. The mutations were present in grade II, III, and IV astrocytic glioma areas. Both severe functionally dead mutants and mutants with remaining transcriptional activity could be observed in the same tumor. We observed that morphologically different parts of a glioma could carry different or similar mutations in the p53 gene and could be either associated or not associated with the locus of heterozygosity at the mutant site. Coexistence of p53 gene mutations and the locus of heterozygosity was common, at least in astrocytomas grade III and in glioblastomas, and also occurred in astrocytoma grade 11 areas. These results support the notion that intratumoral heterogeneity in brain tumors originates from different molecular defects. Our results are of importance for a further understanding of the molecular mechanisms behind failure to treat glioma patients.
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| 12. |
- Russo, Antonio, et al.
(författare)
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The TP53 colorectal cancer international collaborative study on the prognostic and predictive significance of p53 mutation : influence of tumor site, type of mutation, and adjuvant treatment.
- 2005
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Ingår i: Journal of Clinical Oncology. - 0732-183X .- 1527-7755. ; 23:30, s. 7518-7528
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aims of the TP53 Colorectal Cancer (CRC) International Collaborative Study were to evaluate the possible associations between specific TP53 mutations and tumor site, and to evaluate the prognostic and predictive significance of these mutations in different site, stage, and treatment subgroups. PATIENTS AND METHODS: A total of 3,583 CRC patients from 25 different research groups in 17 countries were recruited to the study. Patients were divided into three groups according to site of the primary tumor. TP53 mutational analyses spanned exons 4 to 8. RESULTS: TP53 mutations were found in 34% of the proximal colon tumors and in 45% of the distal colon and rectal tumors. They were associated with lymphatic invasion in proximal tumors. In distal colon tumors, deletions causing loss of amino acids were associated with worse survival. In proximal colon tumors, mutations in exon 5 showed a trend toward statistical significance (P < .05) when overall survival was considered. Dukes' C tumors with wild-type TP53 and those with mutated TP53 (proximal tumors) showed significantly better prognosis when treated with adjuvant chemotherapy. CONCLUSION: Analysis of TP53 mutations from a large cohort of CRC patients has identified tumor site, type of mutation, and adjuvant treatment as important factors in determining the prognostic significance of this genetic alteration.
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| 13. |
- Soussi, Thierry
(författare)
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Benign SNPs in the Coding Region of TP53 : Finding the Needles in a Haystack of Pathogenic Variants
- 2022
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Ingår i: Cancer Research. - : American Association for Cancer Research. - 0008-5472 .- 1538-7445. ; 82:19, s. 3420-3431
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Forskningsöversikt (refereegranskat)abstract
- With the recent explosion in high-throughput genotyping tech-nology, the amount and quality of SNP data have increased expo-nentially, facilitating the discovery of multiple uncommon SNPs in the human population. To provide unified and centralized resources for the scientific community, several repositories have been devel-oped that aggregate numerous population studies and serve widely as references to filter natural variants in genetic analyses. However, they are largely biased toward European populations. TP53 gene is the most frequently mutated gene in human cancer, and pathogenic germline TP53 variants are associated with several cancer suscep-tibility disorders such as Li-Fraumeni syndrome. For these reasons, it is essential that TP53 SNPs are rigorously evaluated to avoid misclassifications that could impair patient management. The recent discovery of numerous benign SNPs within the coding region of TP53 can be attributed to surveillance of both global repositories and population-specific databases, with the latter enabling the recognition of additional TP53 SNPs in Japanese, African, and Indian populations. This review summarizes the body of evidence behind the identification of 21 TP53 variants and the information defining them as bona fide SNPs. This illustrates the need to include populations of different ethnic origins in genetic studies and the substantial benefits that can be derived from the information.
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| 14. |
- Soussi, Thierry, et al.
(författare)
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Landscape of TP53 Alterations in Chronic Lymphocytic Leukemia via Data Mining Mutation Databases
- 2022
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Ingår i: Frontiers in Oncology. - : Frontiers Media S.A.. - 2234-943X. ; 12
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Forskningsöversikt (refereegranskat)abstract
- Locus-specific databases are invaluable tools for both basic and clinical research. The extensive information they contain is gathered from the literature and manually curated by experts. Cancer genome sequencing projects generate an immense amount of data, which are stored directly in large repositories (cancer genome databases). The presence of a TP53 defect (17p deletion and/or TP53 mutations) is an independent prognostic factor in chronic lymphocytic leukemia (CLL) and TP53 status analysis has been adopted in routine clinical practice. For that reason, TP53 mutation databases have become essential for the validation of the plethora of TP53 variants detected in tumor samples. TP53 profiles in CLL are characterized by a great number of subclonal TP53 mutations with low variant allelic frequencies and the presence of multiple minor subclones harboring different TP53 mutations. In this review, we describe the various characteristics of the multiple levels of heterogeneity of TP53 variants in CLL through the analysis of TP53 mutation databases and the utility of their diagnosis in the clinic.
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| 15. |
- Soussi, Thierry
(författare)
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Letter to the editor
- 2023
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Ingår i: Human Molecular Genetics. - : Oxford University Press. - 0964-6906 .- 1460-2083. ; 32:13, s. 2121-2123
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 16. |
- Thierry, Gaelle, et al.
(författare)
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Molecular characterization of 1q44 microdeletion in 11 patients reveals three candidate genes for intellectual disability and seizures
- 2012
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Ingår i: American Journal of Medical Genetics. Part A. - : Wiley. - 1552-4825 .- 1552-4833. ; 158A:7, s. 1633-1640
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Tidskriftsartikel (refereegranskat)abstract
- Patients with a submicroscopic deletion at 1q43q44 present with intellectual disability (ID), microcephaly, craniofacial anomalies, seizures, limb anomalies, and corpus callosum abnormalities. However, the precise relationship between most of deleted genes and the clinical features in these patients still remains unclear. We studied 11 unrelated patients with 1q44 microdeletion. We showed that the deletions occurred de novo in all patients for whom both parents' DNA was available (10/11). All patients presented with moderate to severe ID, seizures and non-specific craniofacial anomalies. By oligoarray-based comparative genomic hybridization (aCGH) covering the 1q44 region at a high resolution, we obtained a critical deleted region containing two coding genesHNRNPU and FAM36Aand one non-coding geneNCRNA00201. All three genes were expressed in different normal human tissues, including in human brain, with highest expression levels in the cerebellum. Mutational screening of the HNRNPU and FAM36A genes in 191 patients with unexplained isolated ID did not reveal any deleterious mutations while the NCRNA00201 non-coding gene was not analyzed. Nine of the 11 patients did not present with microcephaly or corpus callosum abnormalities and carried a small deletion containing HNRNPU, FAM36A, and NCRNA00201 but not AKT3 and ZNF238, two centromeric genes. These results suggest that HNRNPU, FAM36A, and NCRNA00201 are not major genes for microcephaly and corpus callosum abnormalities but are good candidates for ID and seizures.
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| 17. |
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| 18. |
- Zhang, Qiang, et al.
(författare)
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Evolutionary history of the p53 family DNA-binding domain : insights from an Alvinella pompejana homolog
- 2022
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Ingår i: Cell Death and Disease. - : Springer Nature. - 2041-4889. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- The extremophile Alvinella pompejana, an annelid worm living on the edge of hydrothermal vents in the Pacific Ocean, is an excellent model system for studying factors that govern protein stability. Low intrinsic stability is a crucial factor for the susceptibility of the transcription factor p53 to inactivating mutations in human cancer. Understanding its molecular basis may facilitate the design of novel therapeutic strategies targeting mutant p53. By analyzing expressed sequence tag (EST) data, we discovered a p53 family gene in A. pompejana. Protein crystallography and biophysical studies showed that it has a p53/p63-like DNA-binding domain (DBD) that is more thermostable than all vertebrate p53 DBDs tested so far, but not as stable as that of human p63. We also identified features associated with its increased thermostability. In addition, the A. pompejana homolog shares DNA-binding properties with human p53 family DBDs, despite its evolutionary distance, consistent with a potential role in maintaining genome integrity. Through extensive structural and phylogenetic analyses, we could further trace key evolutionary events that shaped the structure, stability, and function of the p53 family DBD over time, leading to a potent but vulnerable tumor suppressor in humans.
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