Germline TP53 mutations undergo copy number gain years prior to tumor diagnosis
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ABSTRACT:
PROVIDER: EGAS00001005982 | EGA |
REPOSITORIES: EGA
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Project description:Li-Fraumeni syndrome (LFS) is a rare, clinically and genetically heterogeneous inherited cancer syndrome. Most cases are due to mutations in TP53. CHK2 is a minor predisposing locus; we recently mapped a third locus to 1q23. In both TP53 and non-TP53 LFS, there is evidence for risk heterogeneity within and between kindreds, suggesting additional risk modifiers. Using BAC- and SNP-based microarrays, we performed genomic profiling of primary soft tissue sarcomas, osteosarcomas and matching constitutive samples of 10 LFS patients (6 with and 4 without TP53 mutations), to identify genome-wide patterns of copy number changes and loss-of-heterozygosity (LOH). Our complementing global approaches revealed several interesting patterns for TP53 and non-TP53 LFS tumors, including positive (1q/7, 3p/15, 4q/9q, 8q/19p, 9p/10q, 13/14 and 15q/18q) and negative (2q/9q, 3q/14q and 4q/6q) associations between chromosomal regions. The region containing the oncogene TWIST1 (7p21.1) was the most common gain independent of TP53 status and tumor type, while LOH of 8q11.2 with the tumor suppressor ST18 was the only region exclusively associated with non-TP53 soft tissue sarcomas. We resequenced known mutations in BRAF, KRAS and NRAS and identified somatic NRAS mutations in 2 of 10 tumors. TP53 and non-TP53 LFS tumors shared multiple hits in genes of the p53 and overlapping pathways. Although common dogma in cancer genetics holds that multiple hits in the same pathway are redundant and thus unlikely, we show that different combinations of genetic alterations in both TP53 and non-TP53 LFS tumors appear to act together in the p53 network in LFS tumorigenesis Keywords: Comparative genomic hybridization Using the Spectral Genomics dye-swap BAC arrays we studied 10 Li Fraumeni syndrome tumor cases
2008-07-16 | E-GEOD-8798 | biostudies-arrayexpress
Project description:Multiple family members with cancer or individuals with multiple primary cancers are indicative of potential genetic etiology1. Germline mutations in TP53 cause a rare high penetrance cancer syndrome, Li Fraumeni Syndrome (LFS)2. We identified a TP53 tetramerization domain (TD) missense mutation c.1000G>C;p.G334R, in a family with LFS-associated cancers. Twenty-one additional probands were identified, and available tumors showed biallelic somatic inactivation of TP53. The majority of families were of Ashkenazi Jewish descent, and the TP53 c.1000G>C allele was found on a commonly inherited haplotype. While classical p53 target gene activation was maintained in p.G334R mutant cell lines treated with Nutlin-3a, a subset of p53 target genes, including PCLO, PLTP, PLXNB3 and LCN15, showed defective transactivation. Structural analysis demonstrated thermal instability of the mutant TD, and the G334R mutant protein showed increased preponderance of mutant conformation protein. TP53 c.1000G>C;p.G334R is a rare AJ-predominant mutation associated with low penetrance Li-Fraumeni Syndrome
2020-07-24 | GSE143741 | GEO
Project description:Whole-genome sequence (WGS) analysis of tumors from 22 TP53 mutation carriers. We observed somatic mutations affecting Wnt, PI3K/AKT signaling, epigenetic modifiers and homologous recombination genes as well as mutational signatures associated with prior chemotherapy. We identified near-ubiquitous early loss of heterozygosity of TP53, with gain of the mutant allele. This occurred earlier in these tumors compared to tumors with somatic TP53 mutations, suggesting the timing of this mark may distinguish germline from somatic TP53 mutations. Phylogenetic trees of tumor evolution, reconstructed from bulk and multi-region WGS, revealed that LFS tumors exhibit comparatively limited heterogeneity. Overall, our study delineates early copy number gains of mutant TP53 as a characteristic mutational process in LFS tumorigenesis, likely arising very early in life or in utero.years prior to tumor diagnosis.
| EGAD00001009280 | EGA
Project description:Li-Fraumeni syndrome (LFS) is a rare, clinically and genetically heterogeneous inherited cancer syndrome. Most cases are due to mutations in TP53. CHK2 is a minor predisposing locus; we recently mapped a third locus to 1q23. In both TP53 and non-TP53 LFS, there is evidence for risk heterogeneity within and between kindreds, suggesting additional risk modifiers. Using BAC- and SNP-based microarrays, we performed genomic profiling of primary soft tissue sarcomas, osteosarcomas and matching constitutive samples of 10 LFS patients (6 with and 4 without TP53 mutations), to identify genome-wide patterns of copy number changes and loss-of-heterozygosity (LOH). Our complementing global approaches revealed several interesting patterns for TP53 and non-TP53 LFS tumors, including positive (1q/7, 3p/15, 4q/9q, 8q/19p, 9p/10q, 13/14 and 15q/18q) and negative (2q/9q, 3q/14q and 4q/6q) associations between chromosomal regions. The region containing the oncogene TWIST1 (7p21.1) was the most common gain independent of TP53 status and tumor type, while LOH of 8q11.2 with the tumor suppressor ST18 was the only region exclusively associated with non-TP53 soft tissue sarcomas. We resequenced known mutations in BRAF, KRAS and NRAS and identified somatic NRAS mutations in 2 of 10 tumors. TP53 and non-TP53 LFS tumors shared multiple hits in genes of the p53 and overlapping pathways. Although common dogma in cancer genetics holds that multiple hits in the same pathway are redundant and thus unlikely, we show that different combinations of genetic alterations in both TP53 and non-TP53 LFS tumors appear to act together in the p53 network in LFS tumorigenesis Keywords: Comparative genomic hybridization
2008-07-16 | GSE8798 | GEO
Project description:Li-Fraumeni syndrome (LFS) is a hereditary cancer predisposition syndrome associated with a highly penetrant and diverse tumor spectrum characterized by germline mutations in the TP53 tumor suppressor gene. To better understand how TP53 mutations predispose individuals with LFS to cancer development, we characterized tp53 R217H and R242H zebrafish lines as the first zebrafish p53 hotspot mutants (human R248 and R273H). These mutants have lost several key wildtype p53 functions and recapitulate many LFS phenotypes. Specifically, we have shown that the R217H and R242H alleles result in partial-to-no activation of key p53 target genes, are resistant to apoptosis in a dominant negative manner and exhibit a defective G1 cell-cycle checkpoint in vivo. The loss of these wildtype p53 functions predisposed the fish to develop spontaneous tumors as early as 6 months of age. Tumor histology resembles human sarcomas, a predominant LFS tumor type. tp53 R242H mutants developed tumors earlier with a higher lifetime incidence than tp53 null or R217H mutants, suggesting it is a more aggressive mutation, while the R217H allele may be hypomorphic. Additionally, we observed mutation-specific differences both in the tumor type and sex bias across tp53 null, R217H, and R242H genotypes with associated diverse transcriptomic and DNA methylome profiles, impacting metabolism, cell signalling, and biological macromolecule synthesis and degradation. These tp53 zebrafish mutants demonstrate fidelity to their human counterparts and provide new insights into underlying tumorigenesis mechanisms and kinetics, which may inform more tailored tumor surveillance approaches and novel therapeutic targets in LFS.
2024-05-29 | GSE268283 | GEO
Project description:Li-Fraumeni syndrome (LFS) is a hereditary cancer predisposition syndrome associated with a highly penetrant and diverse tumor spectrum characterized by germline mutations in the TP53 tumor suppressor gene. To better understand how TP53 mutations predispose individuals with LFS to cancer development, we characterized tp53 R217H and R242H zebrafish lines as the first zebrafish p53 hotspot mutants (human R248 and R273H). These mutants have lost several key wildtype p53 functions and recapitulate many LFS phenotypes. Specifically, we have shown that the R217H and R242H alleles result in partial-to-no activation of key p53 target genes, are resistant to apoptosis in a dominant negative manner and exhibit a defective G1 cell-cycle checkpoint in vivo. The loss of these wildtype p53 functions predisposed the fish to develop spontaneous tumors as early as 6 months of age. Tumor histology resembles human sarcomas, a predominant LFS tumor type. tp53 R242H mutants developed tumors earlier with a higher lifetime incidence than tp53 null or R217H mutants, suggesting it is a more aggressive mutation, while the R217H allele may be hypomorphic. Additionally, we observed mutation-specific differences both in the tumor type and sex bias across tp53 null, R217H, and R242H genotypes with associated diverse transcriptomic and DNA methylome profiles, impacting metabolism, cell signalling, and biological macromolecule synthesis and degradation. These tp53 zebrafish mutants demonstrate fidelity to their human counterparts and provide new insights into underlying tumorigenesis mechanisms and kinetics, which may inform more tailored tumor surveillance approaches and novel therapeutic targets in LFS.
2024-05-22 | GSE267760 | GEO
Project description:Specific changes in gene expression during cancer initiation should enable discovery of biomarkers for risk assessment, early detection and targets for chemoprevention. It has been previously demonstrated that altered mRNA and proteome signatures of morphologically normal cells bearing a single inherited âhitâ in a tumor suppressor gene parallel many changes observed in the corresponding sporadic cancer. Here, we report on the global gene expression profile of morphologically normal, cultured primary breast epithelial and stromal cells from Li-Fraumeni syndrome (LFS) TP53 mutation carriers. Our analyses identified multiple changes in gene expression in both morphologically normal breast epithelial and stromal cells associated with TP53 haploinsufficiency, as well as interlocking pathways. Notably, a dysregulated p53 signaling pathway was readily detectable. Pharmacological intervention with the p53 rescue compounds CP-31398 and PRIMA-1 provided further evidence in support of the central role of p53 in affecting these changes in LFS cells and treatment for this cancer. Because loss of signaling mediated by TP53 is associated with the development and survival of many human tumors, identification of gene expression profiles in morphologically normal cells that carry âone-hitâ p53 mutations may reveal novel biomarkers, enabling the discovery of potential targets for chemoprevention of sporadic tumors as well. compare gene expression from different cell types
2010-10-21 | E-GEOD-23994 | biostudies-arrayexpress
Project description:Li-Fraumeni syndrome (LFS) is a hereditary cancer predisposition syndrome caused by germline mutations in TP53. TP53 is the most common mutated gene in human cancer occurring in 30-50% of glioblastomas (GBM). Here, we highlight a precision medicine platform to identify potential targets for a GBM patient with LFS. We used novel comparative transcriptomics analysis to identify genes that are uniquely overexpressed in a LFS GBM patient relative to a cancer compen-dium of 12,747 tumor RNA sequencing datasets including 200 GBMs. We then used ex vivo pa-tient derived organoid (PDO) viability assays with 4 patient derived cell lines to test efficacy of our identified target. Our comparative transcriptomics bioinformatics pipeline identified that STAT1 and STAT2 were significantly overexpressed in our patient indicating ruxolitinib, a Janus kinase 1 and 2 inhibitor, as a potential therapy. In our institutional high-grade glioma cohort of 45 patients, the LFS patient had the highest level of STAT1 and STAT2 expression. STAT1 and STAT2 expression levels in 4 cell lines derived from patients (including the LFS patient) corre-lated with levels identified in the respective parent tumors. Using 2D and 3D assays from pa-tient derived cells, our LFS patient of interest was among the most sensitive to ruxolitinib in comparison to patients with lower STAT1 and STAT2 expression levels. Additionally a sphe-roid-based drug screening assay (3D-PREDICT) was performed and used to identify further therapeutic targets. This manuscript supports the use of comparative transcriptomics to identify personalized therapeutic targets in a functional precision medicine platform for malignant brain tumors.
2021-12-02 | GSE188739 | GEO
Project description:Specific changes in gene expression during cancer initiation should enable discovery of biomarkers for risk assessment, early detection and targets for chemoprevention. It has been previously demonstrated that altered mRNA and proteome signatures of morphologically normal cells bearing a single inherited “hit” in a tumor suppressor gene parallel many changes observed in the corresponding sporadic cancer. Here, we report on the global gene expression profile of morphologically normal, cultured primary breast epithelial and stromal cells from Li-Fraumeni syndrome (LFS) TP53 mutation carriers. Our analyses identified multiple changes in gene expression in both morphologically normal breast epithelial and stromal cells associated with TP53 haploinsufficiency, as well as interlocking pathways. Notably, a dysregulated p53 signaling pathway was readily detectable. Pharmacological intervention with the p53 rescue compounds CP-31398 and PRIMA-1 provided further evidence in support of the central role of p53 in affecting these changes in LFS cells and treatment for this cancer. Because loss of signaling mediated by TP53 is associated with the development and survival of many human tumors, identification of gene expression profiles in morphologically normal cells that carry “one-hit” p53 mutations may reveal novel biomarkers, enabling the discovery of potential targets for chemoprevention of sporadic tumors as well.
2010-10-21 | GSE23994 | GEO
Project description:In vitro modeling of human disease has recently become feasible with the adoption of induced pluripotent stem cell (iPSC) technology. Here, we established patient-derived iPSCs from an Li-Fraumeni Syndrome (LFS) family and investigated the role of mutant p53 in the development of osteosarcoma (OS). Several members of this family carried a heterozygous p53(G245D) mutation and presented with a broad spectrum of tumors including OS. Osteoblasts (OBs) differentiated from iPSC-derived mesenchymal stem cells (MSCs) recapitulated OS features including defective osteoblastic differentiation (OB differentiation) as well as tumorigenic ability. Systematic analyses revealed that the expression of genes enriched in LFS-derived OBs strongly correlated with decreased time to tumor recurrence and poor patient survival. In silico cytogenetic region enrichment analysis (CREA) demonstrated that LFS-derived OBs do not have genomic rearrangements and hence are a particularly valuable tool for elucidating early oncogenic events prior to the accumulation of secondary alterations. LFS OBs exhibited impaired upregulation of the imprinted gene H19 during osteogenesis. Restoration of H19 expression in LFS OBs facilitated osteogenic differentiation and repressed tumorigenic potential. By integrating human imprinted gene network (IGN) and functional genomic analyses, we found that H19-mediates suppression of LFS-associated OS through the IGN component DECORIN (DCN). Downregulation of DCN impairs H19-mediated osteogenic differentiation and tumor suppression. In summary, these findings demonstrate the feasibility of studying inherited human cancer syndromes with iPSCs and also provide molecular insights into the role of the IGN in p53 mutation-mediated tumorigenesis. mRNAseq profiling during mesenchymal stem cell differentiation to osteoblasts.
2015-04-10 | E-GEOD-58123 | biostudies-arrayexpress