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
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.
Project description:Whole Exome sequencing of two patients with Cardiac angiosarcoma in Li-Fraumeni-like families discovers that a mutation in the pot1 gene is responsible for cardiac angiosarcoma in tp53-negative li-fraumeni-like families
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
Project description:The TP53-R337H founder mutation exists at high frequency throughout southern Brazil and represents the most common germline TP53 mutation reported to date. It was originally identified in pediatric adrenocortical tumors in families with no reported history of cancer. The R337H mutation has since been found in association with early-onset breast cancers and Li-Fraumeni syndrome. To study this variability in tumor susceptibility we generated a knockin mutant p53 mouse model (R334H). Endogenous murine R334H is naturally expressed at abnormally high levels in multiple tissues and is functionally compromised in a cell type and stress-specific manner. The mutant p53 mice develop tumors with long latency and incomplete penetrance, consistent with many human carriers being at a low, but elevated risk for cancer We used microarrays to compare the global programme of gene expression in thymocytes obtained from WT or TP53R337H/R337H mutant mice that had either received 5 Gy whole body irradiation or no irradiation.
Project description:We report the application for high-throughput profiling of transcriptome, chromatin-associated proteins and histone-modifications on a genome-wide level in iPSC-derived family control astrocytes vs LFS (Li-Fraumeni Syndrome) patient astrocytes.