Project description:Lynch syndrome (LS) patients are at markedly increased risk for colorectal cancer. It is being increasingly recognized that the immune system plays an essential role in LS tumor development. Therefore, immune interception strategies are emerging as a novel way to prevent cancer in LS. This phase Ib, placebo-controlled, randomized clinical trial and a co-clinical trial using a LS mouse model and patient-derived organoids aims to evaluate the safety and tolerability as well as to discover novel molecular pathways involved in the activity of Naproxen as chemoprevention in LS patients.
Project description:Purpose: Lynch syndrome (LS) is a hereditary cancer syndrome. Systemic circulating microRNA expression levels (c-miRnome) in LS carriers have not been characterized previously. This exploratory study characterized the systemic c-miRnomes of LS carriers with or without cancer and compared it to c-miRnomes of sporadic rectal cancer patients and healthy controls. Methods: Blood serum samples of Lynch syndrome carriers without (n=81) or with (n=13) cancer, sporadic rectal cancer patients (n=24) and healthy controls (n=37) were sequenced with NextSeq500. FastQC was used for quality controls. High quality samples with Phred score >25 were selected for downstream analysis. FastX-toolkit was used for trimming and filtering. Mapping of the reads to miRbase (v.22) was conducted with Bowtie with v-mode and best strata parameters for single-end data. Only the uniquely mapped reads were selected for differential expression (DE) analysis. Dimension reduction analysis was conducted with t-SNE. Target gene prediction and pathway analysis was performed with mirWalk and validated with COSMIC-database. Results: An average of 3.2M reads pers sample was achieved. We identified a pool of 228 c-miRs common to all study groups that was used to setup the design matrix for DE analysis. We identified a c-miRnome of 40 DE c-miRs that discern healthy LS carriers from healthy controls but could not distinguish them from cancer patients with or without LS. Our results suggested that hereditary and sporadic carcinogenesis share common biological pathways and alterations in these pathways generate a c-miR response, which can be used to track oncogenic stress at cancer-free state in LS. Conclusion: Our results show that c-miRs hold diagnostic and predictive potential in molecular profiling of human cancers.
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.
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.
Project description:Approximately 15% of colorectal cancer (CRC) patients present with high levels of microsatellite instability (MSI-H), which is driven by defective mismatch repair (dMMR). While about 20% of MSI-H tumors are associated with the hereditary condition, Lynch syndrome (LS), the majority develop through non-hereditary mechanisms. In recent years, the molecular processes underpinning tumor development in LS patients has been debated, with the longstanding view that dMMR is a secondary process in CRC development of LS patients being questioned. Here, we performed the first multi-omic analysis of normal colon organoids developed from LS and healthy patients to address questions regarding the development of dMMR in LS colon epithelial cells from cancer-free individuals.
Project description:Approximately 15% of colorectal cancer (CRC) patients present with high levels of microsatellite instability (MSI-H), which is driven by defective mismatch repair (dMMR). While about 20% of MSI-H tumors are associated with the hereditary condition, Lynch syndrome (LS), the majority develop through non-hereditary mechanisms. In recent years, the molecular processes underpinning tumor development in LS patients has been debated, with the longstanding view that dMMR is a secondary process in CRC development of LS patients being questioned. Here, we performed the first multi-omic analysis of normal colon organoids developed from LS and healthy patients to address questions regarding the development of dMMR in LS colon epithelial cells from cancer-free individuals.
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.
Project description:Lynch syndrome (LS) patients develop DNA mismatch repair deficient tumors which generate high loads of neoantigens (neoAgs), thus constituting a well-defined population that can benefit from cancer immune-interception strategies, including neoantigen-based vaccines. Using paired whole-exome sequencing and mRNAseq of colorectal cancers (CRC) (n=13) and pre-cancers (n=61) from our LS patient cohort (N=46), we performed in-silico prediction and immunogenicity ranking of highly recurrent frameshift-neoags, followed by their in-vitro validation. We described the somatic mutation landscape in all cancers and pre-cancers, and showed that mutation burden is positively correlated with neoAgs load. Furthermore, our in-vitro validation showed a 65% validation rate of our top 100 predicted neoags. Consistent with neoAgs burden, our transcriptomic results revealed increased infiltration of CD8+ and CD4+ T-cells in microsatellite unstable samples. Overall, our neoAgs catalog and all other findings, improve our understanding of cancer development in LS and guide us towards the advancement of immunoprevention vaccine strategies.
Project description:Lynch syndrome (LS), or hereditary nonpolyposis colorectal cancer (HNPCC), is a hereditary disorder predisposing for colorectal cancer. To reduce the risk of colorectal cancer, patients undergo colonoscopy every 1-2 years. Chromoendoscopy is relatively new technique which improves the detection of adenomas, the precursor lesions of colorectal cancer. The aim of this study is to determine whether chromoendoscopy, including polypectomy of all detected lesions, reduces the development of colorectal neoplasia and the need for colectomy in LS patients.
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.