Ab88170a-f536-4ebc-a2bb-7c2caa17733d - samples
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ABSTRACT:
PROVIDER: EGAD00001010200 | EGA |
REPOSITORIES: EGA
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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:In more than 70% of families with a strong history of breast and ovarian cancers, pathogenic mutation in BRCA1 or BRCA2 cannot be identified, even though hereditary factors are expected to be involved. It has been proposed that tumors with similar molecular phenotypes also share similar pathophysiological mechanisms. Grouping into molecularly homogeneous subsets may therefore be of potential value for further genetic analysis in order to identify new high penetrance breast cancer genes. In the current study, the aim was to investigate if global RNA profiling can be used to identify functional subgroups within breast tumors from families tested negative for BRCA1/2 germline mutations and how these subgroupings relate to different breast cancer patients within the same family. By analyzing a collection of 70 breast tumor biopsies from 58 families, we show that distinct functional subgroupings, similar to the intrinsic molecular breast cancer subtypes, exist. The distribution of subtypes was markedly different from the distribution found among BRCA1/2 mutation carriers. From 11 breast cancer families, breast tumor biopsies from more than one affected family member were included in the study. Notably, in 8 of these families we found that patients from the same family shared the same tumor subtype, showing a tendency of familial aggregation of tumor subtypes (p-value = 1.7e-3). Our finding indicates involvement of hereditary factors in these families in which family members may carry genetic susceptibility not just to breast cancer but to a particular subtype of breast cancer. Using our previously developed BRCA1/2-signatures, we identified 7 non-BRCA1/2 tumors with a BRCA1-like molecular phenotype and provide evidence for epigenetic inactivation of BRCA1 in three of the tumors. In addition, 7 BRCA2-like tumors were found. This is the first study to provide a biological link between breast cancers from family members of high risk non-BRCA1/2 families in a systematic manner, suggesting that future genetic analysis may benefit from subgrouping families into molecularly homogeneous subtypes in order to identify new high penetrance susceptibility genes.
2015-08-01 | GSE49481 | GEO
Project description:The cystic leukoencephalopathy without megalencephaly has been defined as distinct autosomal-recessive syndrome of quasi-static encephalopathy with normo- or microcephaly, impaired psychomotor development and characteristic pattern on brain MRI. We identified mutations in the gene encoding the RNASET2 glycoprotein in seven affected individuals as the cause of disease. The results suggest that RNASET2 plays an important role in central nervous system myelination and development. 2-Color dye swap design independent for two different families including technical and biologial replicates for affected family members (disease) and not affected family members (controls).
2009-06-02 | E-GEOD-11964 | biostudies-arrayexpress
Project description:In more than 70% of families with a strong history of breast and ovarian cancers, pathogenic mutation in BRCA1 or BRCA2 cannot be identified, even though hereditary factors are expected to be involved. It has been proposed that tumors with similar molecular phenotypes also share similar pathophysiological mechanisms. Grouping into molecularly homogeneous subsets may therefore be of potential value for further genetic analysis in order to identify new high penetrance breast cancer genes. In the current study, the aim was to investigate if global RNA profiling can be used to identify functional subgroups within breast tumors from families tested negative for BRCA1/2 germline mutations and how these subgroupings relate to different breast cancer patients within the same family. By analyzing a collection of 70 breast tumor biopsies from 58 families, we show that distinct functional subgroupings, similar to the intrinsic molecular breast cancer subtypes, exist. The distribution of subtypes was markedly different from the distribution found among BRCA1/2 mutation carriers. From 11 breast cancer families, breast tumor biopsies from more than one affected family member were included in the study. Notably, in 8 of these families we found that patients from the same family shared the same tumor subtype, showing a tendency of familial aggregation of tumor subtypes (p-value = 1.7e-3). Our finding indicates involvement of hereditary factors in these families in which family members may carry genetic susceptibility not just to breast cancer but to a particular subtype of breast cancer. Using our previously developed BRCA1/2-signatures, we identified 7 non-BRCA1/2 tumors with a BRCA1-like molecular phenotype and provide evidence for epigenetic inactivation of BRCA1 in three of the tumors. In addition, 7 BRCA2-like tumors were found. This is the first study to provide a biological link between breast cancers from family members of high risk non-BRCA1/2 families in a systematic manner, suggesting that future genetic analysis may benefit from subgrouping families into molecularly homogeneous subtypes in order to identify new high penetrance susceptibility genes. Gene expression profiling of 253 breast tumor samples. Breast tumor tissue from 125 patients with germline mutations in BRCA1 (n = 33) or BRCA2 (n = 22) or with no detectable germline mutation in BRCA1 or BRCA2 (n = 70) were included in the study. Serving as a representative control group, primary breast tumor samples (n = 128) were randomly selected among available samples originating from the same department and time period as for the hereditary samples. The study was conducted using Agilent-029949 Custom SurePrint G3 Human GE 8x60K Microarray platform.
2015-08-01 | E-GEOD-49481 | biostudies-arrayexpress
Project description:In animals, microRNAs frequently form families with related sequences. The functional relevance of miRNA families and the relative contribution of family members to target repression have remained, however, largely unexplored. Here, we used the C. elegans miR-58 miRNA family, comprised primarily of four highly abundant members: miR-58.1, miR-80, miR-81 and miR-82, as a model to investigate the redundancy of miRNA family members and their impact on target expression in an in vivo setting.
2015-06-05 | GSE60420 | GEO
Project description:In animals, microRNAs frequently form families with related sequences. The functional relevance of miRNA families and the relative contribution of family members to target repression have remained, however, largely unexplored. Here, we used the C. elegans miR-58 miRNA family, comprised primarily of four highly abundant members: miR-58.1, miR-80, miR-81 and miR-82, as a model to investigate the redundancy of miRNA family members and their impact on target expression in an in vivo setting.
2015-06-05 | GSE60419 | 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: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:We describe a multiple de novo CNV (MdnCNV) phenomenon in which individuals with genomic disorders carry five to ten constitutional de novo CNVs. Five such families are studied, which consists of four trios and one singleton. Various array platforms are used to interogate these families to identify de novo CNVs.
2016-10-14 | GSE87909 | GEO
Project description:We describe a multiple de novo CNV (MdnCNV) phenomenon in which individuals with genomic disorders carry five to ten constitutional de novo CNVs. Five such families are studied, which consists of four trios and one singleton. Various array platforms are used to interogate these families to identify de novo CNVs.
2016-10-14 | GSE87838 | GEO