Project description:<p>International differences in the incidence of many cancer types indicate the existence of carcinogen exposures that have not been identified by conventional epidemiology yet potentially make a substantial contribution to cancer burden1. This pertains to clear cell renal cell carcinoma (ccRCC), for which obesity, hypertension, and tobacco smoking are risk factors but do not explain its geographical variation in incidence2. Some carcinogens generate somatic mutations and a complementary strategy for detecting past exposures is to sequence the genomes of cancers from populations with different incidence rates and infer underlying causes from differences in patterns of somatic mutations. Here, we sequenced 962 ccRCC from 11 countries of varying incidence. Somatic mutation profiles differed between countries. In Romania, Serbia and Thailand, mutational signatures likely caused by extracts of Aristolochia plants were present in most cases and rare elsewhere. In Japan, a mutational signature of unknown cause was found in >70% cases and <2% elsewhere. A further mutational signature of unknown cause was ubiquitous but exhibited higher mutation loads in countries with higher kidney cancer incidence rates (p-value <6 × 10−18). Known signatures of tobacco smoking correlated with tobacco consumption, but no signature was associated with obesity or hypertension suggesting non-mutagenic mechanisms of action underlying these risk factors. The results indicate the existence of multiple, geographically variable, mutagenic exposures potentially affecting 10s of millions of people and illustrate the opportunities for new insights into cancer causation through large-scale global cancer genomics.</p><p><br></p><p><strong>Linked cross omic data sets:</strong></p><p>Geographic variation of mutagenic exposures in kidney cancer genomes – patient metadata files (<strong>Mutographs</strong>) associated with this study are available in the <strong>European Genome-Phenome Archive</strong>: https://ega-archive.org/datasets/EGAD00001012223.</p>
Project description:Mutational signatures in esophageal squamous cell carcinoma from eight countries of varying incidence – patient metatdata (Mutographs)
Project description:The Mutographs project aims to advance our understanding of the causes of cancer through studies of mutational signatures. Led by Mike Stratton, together with Paul Brennan, Ludmil Alexandrov, Allan Balmain, David Phillips and Peter Campbell, this large-scale international research endeavour was awarded a Cancer Research UK Grand Challenge. Different patterns of somatic mutation are generated by the different environmental, lifestyle and genetic factors that cause cancer, many of them are still unknown. Within Mutographs, the International Agency for Research on Cancer is coordinating the recruitment of 5000 individuals with cancer (colorectal, renal, pancreatic, oesophageal adenocarcinoma or oesophageal squamous cancers) across 5 continents to explore whether different mutational signatures explain marked variation in incidence. In brief, through an international network of collaborators around the world, biological materials are collected, along with demographic, histological, clinical and questionnaire data. Whole genome sequences of tumour-germline DNA pairs are generated at the Wellcome Trust Sanger Institute. Somatic mutational signatures are subsequently extracted by non-negative matrix factorisation methods and correlated with risk factors data. Through an enhanced understanding of cancer aetiology, Mutographs unprecedented effort is anticipated to outline modifiable risk factors, lead to new approaches to prevent cancer, and provide opportunities to empower early detection, refine high-risk groups and contribute to further therapeutic development.
Project description:Aristolochic acid (AA) is an active component of herbal drugs derived from the Aristolochia species that have been used for medicinal purposes since antiquity. However, AA is genotoxic and induces tumors in animals and humans. AA induces mutations and tumors in the kidney but solely mutations in the liver. To evaluate whether miRNAs could indicate AA’s tissue-specific carcinogenicity and mutagenicity, we first conducted microarray analysis of miRNA expression in kidneys and livers of rats treated with a carcinogenic dose of AA. Then, miR-21, a biomarker for carcinogenicity, and miR-34a, a biomarker for mutagenicity, the two miRNAs whose expressions were most altered, were evaluated for their expression in the kidney (the AA’s mutagenic and carcinogenic target tissue), liver (the AA’s mutagenic target tissue), and testis, the non-target tissue where neither tumors nor mutation induction was found in previous studies and in this study. Genomic analysis of miRNA expression for kidney and liver samples showed that miRNA expression was globally changed by the treatment. Nineteen miRNAs were significantly dysregulated by the treatment in the kidney. Most of these miRNAs are related to carcinogenesis. Only one miRNA, miR-34a, was differentially expressed in the liver. Expression of miR-21 was induced in the kidney by AA treatment in a dose-dependent manner while no changes occurred in the liver or testis, indicating that the kidney is the carcinogenic target. miR-34a was dose-dependently up-regulated in the kidneys and livers of rats treated with AA, but not in the testis, suggesting that the kidney and liver are mutagenic target tissues, but the testis is not. Our results demonstrate that miRNA profiles can reflect the AA’s carcinogenicity in a tissue-specific manner while specific miRNAs can signify the target tissues for carcinogenicity or mutagenicity of AA.
Project description:The long term objective is to create an encyclopedia of the expression levels of all genes in multiple components of the developing kidney. The central thesis is straightforward. The combination of fluorescent activated cell sorting (FACS) plus microarray analysis offers a powerful, efficient and effective method for the creation of a global gene expression atlas of the developing kidney. Microarrays with essentially complete genome coverage can be used to quantitate expression levels of every gene in FACS isolated components of the developing kidney. The ensuing rapid read-out provides an expression atlas that is more sensitive, more economical and more complete than would be possible by in situ hybridizations alone. Tie2-GFP transgenic mice were utilized to isolate the endothelial cell population from the glomerulus of adult kidneys. The glomerular endothelial cells were isolated from kidneys using a combination of collagenase treatment, differential seiving, trypsin treatment and FACS. The RNA was isolated from purified endothelial cells and the gene expression profiles were determined by microarrays.