Molecular analysis of cancer genomes in children with Lynch syndrome: exploring causal associations
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PROVIDER: EGAS00001006992 | EGA |
REPOSITORIES: EGA
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Project description:Lynch syndrome (LS) predisposes to cancer in adulthood and is caused by heterozygous germline variants in a mismatch repair (MMR) gene. Recent studies show an increased prevalence of LS among children with cancer, suggesting a causal relationship. For LS-spectrum (LSS) cancers, including high-grade gliomas and colorectal cancer, causality has been supported by typical MMR-related tumor characteristics, but for non-LSS cancers, causality is unclear. This dataset contains 5 patients with Lynch Syndrome from the INFORM registry.
| EGAS00001007146 | EGA
Project description:Lynch syndrome and Familial colorectal cancer type X (FCCTX) are clinically diagnosed using the same criteria, but genomic differences exist between these two groups and the genomic profiles share similarities with their sporadic counterparts, mismatch repair (MMR) deficient and proficient tumors, respectively. Array-based comparative genomic hybridization was performed on 91 tumors, comprising 23 Lynch syndrome (AH), 23 FCCTX (AA), 23 sporadic MMR deficient (AM) and 22 sporadic MMR proficient tumors, in order to identify differences between Lynch syndrome and FCCTX.
2012-06-01 | E-GEOD-38405 | biostudies-arrayexpress
Project description:Background: In ~50% of Lynch syndrome (LS)-suspected patients (also called Lynch-like syndrome, LLS), the causal mechanism for cancer predisposition remains unknown. Our aim was to elucidate the constitutional basis of mismatch repair (MMR) deficiency in LLS patients throughout a comprehensive genetic and epigenetic analysis. Methods: One hundred and fifteen LLS patients harboring MMR deficient tumors and no pathogenic germline MMR gene mutations were included in this study. Mutational analysis of 26 colorectal cancer associated genes was performed by using a customized multigene panel and massively parallel sequencing. Pathogenicity of MMR variants was assessed by mRNA analysis and multifactorial likelihood calculations. Genome-wide methylome analysis was perfomed by using the Infinium HumanMethylation450K BeadChip. Results: The multigene panel analysis revealed the presence of two MMR gene truncating mutations not found in previous analysis. Of a total of 15 MMR variants of unknown significance identified, five - present in 6 unrelated individuals- were reclassified as pathogenic. In addition, 13 predicted deleterious variants in other CRC-predisposing genes (MSH3, MUTYH, POLD1, APC, EPCAM, BUB1, FAN1, EXO1 or PSM1) were found in 12 probands. Methylome analysis detected one constitutional MLH1 epimutation in an individual diagnosed with CRC at age 42, but no additional differentially methylated regions were identified in LLS compared to LS patients or healthy individuals. Conclusions: In conclusion, the use of an ad-hoc designed gene panel combined with pathogenicity assessment of variants allows the identification of deleterious MMR mutations as well as new LLS candidate genes. Moreover, constitutional epimutations in non-LS-associated genes are not responsible for the MMR-deficient phenotype observed in LLS patients.
2019-03-09 | GSE128064 | GEO
Project description:Background: In ~50% of Lynch syndrome (LS)-suspected patients (also called Lynch-like syndrome, LLS), the causal mechanism for cancer predisposition remains unknown. Our aim was to elucidate the constitutional basis of mismatch repair (MMR) deficiency in LLS patients throughout a comprehensive genetic and epigenetic analysis. Methods: One hundred and fifteen LLS patients harboring MMR deficient tumors and no pathogenic germline MMR gene mutations were included in this study. Mutational analysis of 26 colorectal cancer associated genes was performed by using a customized multigene panel and massively parallel sequencing. Pathogenicity of MMR variants was assessed by mRNA analysis and multifactorial likelihood calculations. Genome-wide methylome analysis was perfomed by using the Infinium HumanMethylation450K BeadChip. Results: The multigene panel analysis revealed the presence of two MMR gene truncating mutations not found in previous analysis. Of a total of 15 MMR variants of unknown significance identified, five - present in 6 unrelated individuals- were reclassified as pathogenic. In addition, 13 predicted deleterious variants in other CRC-predisposing genes (MSH3, MUTYH, POLD1, APC, EPCAM, BUB1, FAN1, EXO1 or PSM1) were found in 12 probands. Methylome analysis detected one constitutional MLH1 epimutation in an individual diagnosed with CRC at age 42, but no additional differentially methylated regions were identified in LLS compared to LS patients or healthy individuals. Conclusions: In conclusion, the use of an ad-hoc designed gene panel combined with pathogenicity assessment of variants allows the identification of deleterious MMR mutations as well as new LLS candidate genes. Moreover, constitutional epimutations in non-LS-associated genes are not responsible for the MMR-deficient phenotype observed in LLS patients.
2019-03-09 | GSE128067 | GEO
Project description:Only a small proportion of cases suspected to have Lynch Syndrome (LS) can be explained by mutation in the mismatch repair (MMR) genes. This study aimed to identify rare CNVs that may contribute to an increased risk for hereditary colorectal cancer in patients with MMR proficiency.
2015-11-30 | GSE72667 | GEO
Project description:Only a small proportion of cases suspected to have Lynch Syndrome (LS) can be explained by mutation in the mismatch repair (MMR) genes. This study aimed to identify rare CNVs that may contribute to an increased risk for hereditary colorectal cancer in patients with MMR proficiency.
2015-11-30 | GSE72665 | GEO
Project description:Colorectal carcinomas arising in the context of Lynch syndrome, the most common inherited cancer syndrome, typically show deficiency of the DNA MMR (mismatch repair) system. Lack of functional MMR leads to accumulation of frameshift mutations at micosatellites (microsatellite instability, MSI). High load of highly immunogenic tumor-specific frameshift neoantigens results in strong immune response against Lynch syndrome MSI cancers. Previous studies have shown systemic immune responses against frameshift neoantigens in Lynch syndrome carriers long before tumor manifestation. In the present study, we analyzed the immune profile of normal colorectal mucosa in Lynch syndrome carriers without current or previous cancer history and in Lynch syndrome colorectal cancer patients, as well as of Lynch syndrome colorectal carcinomas. The unsupervised cluster analysis of gene expression data revealed a sharp differentiation between normal mucosa from Lynch syndrome individuals with and without manifest cancer as well as between normal mucosa in general and Lynch syndrome cancer tissue. Deconvolution analysis for predicting the prevalence of immune cell population among the three groups revealed 10 out of 14 investigated populations to be significantly different between the three tissue types (FDR=10%). In contrast to normal mucosa samples, tumor tissue showed overrepresentation of immune-suppressive cell populations, such as regulatory T cells and neutrophils. Taken together with the quantitative T cell density analysis on the basis of immunohistochemical T cell stainings, our data show strong immune infiltration of the normal colorectal mucosa in Lynch syndrome individuals even in the absence of a manifest cancer.
2022-03-14 | GSE178516 | GEO
Project description:Heredity is a major cause of ovarian cancer. Lynch syndrome is associated with 10-12% risk of ovarian cancer, diagnosis at young age and a predilection for endometrioid and clear cell tumors. Global gene expression profiling applied to 25 Lynch syndrome-associated and 42 sporadic ovarian cancers revealed 335 differentially expressed genes and involvement of the mTOR and the MAPK/ERK pathways. The clear cell tumors had distinct expression profiles with upregulation of HER2 and apoptosis signaling pathways. The distinct expression profiles provide clues relevant for hereditary tumorigenesis and may be relevant for therapeutic strategies and refined diagnostics in ovarian cancer linked to Lynch syndrome. Ovarian cancers linked to Lynch syndrome (n=25) were compared to a matched series of sporadic ovarian cancers (n=42), selected from a population-based consecutive series in which hereditary was excluded based on family history, normal MMR protein staining and lack of mutations in BRCA1 and BRCA2.
2013-10-14 | E-GEOD-37394 | biostudies-arrayexpress
Project description:Lynch syndrome and Familial colorectal cancer type X (FCCTX) are clinically diagnosed using the same criteria, but genomic differences exist between these two groups and the genomic profiles share similarities with their sporadic counterparts, mismatch repair (MMR) deficient and proficient tumors, respectively.
2012-06-02 | GSE38405 | GEO
Project description:We have generated a gene signature of mismatch repair (MMR) deficient intestinal stem cells (ISCs) using whole-genome transcriptomics and proteomics from murine intestinal stem cells and epithelial non-stem cells in a Lynch syndrome mouse model (Msh2-fl/fl;Villin-Cre). Then we have validated this signature in RNA-seq data from LS normal unaffected mucosa (UM), adenomas (AD) and adenomas with high-grade dsyplasia (AD-HGD) and tumors (T). MMR status for LS tumors and adenomas with high-grade dysplasia was categorized as KO, for unaffected mucosa as HET and FAP samples as WT.
2021-06-01 | GSE153385 | GEO