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:<p>Desmoplastic melanoma is an infrequent variant of melanoma with sarcomatous histology, distinct clinical behavior, and unknown pathogenesis. We performed low-coverage genome and high-coverage exome sequencing of 20 desmoplastic melanomas, followed by targeted sequencing of 293 genes to validate candidate genes. A high mutation burden (median 62 mutations/Mb) ranked desmoplastic melanoma among the most highly mutated cancers. Mutation patterns strongly implicate UV-radiation as the dominant mutagen, indicating a superficially located cell of origin. Novel alterations included recurrent promoter mutations of NF-kappa B inhibitor epsilon, NFKBIE (IkBε) in 14.5% of samples. Commonly mutated oncogenes in melanomas, in particular BRAF(V600E) and NRAS(Q61K/R), were absent. Instead, other genetic alterations known to activate the MAPK and PI3K signaling cascades were identified in 73% of samples, affecting NF1, CBL, ERBB2, MAP2K1, MAP3K1, BRAF, EGFR, PTPN11, MET, RAC1, SOS2, NRAS, and PIK3CA, some of which being candidates for targeted therapies.</p> <p><i>Reprinted from:</i><br/> Shain, A. H. et al. Exome sequencing of desmoplastic melanoma identifies recurrent NFKBIE promoter mutations and diverse activating mutations in the MAPK pathway. <i>Nat. Genet. <br/> With permission from Nature Genetics</i> </p>
Project description:This is a continuation of the Chordoma Sequencing Project. All cancers arise due to somatically acquired abnormalities in DNA sequence. Systematic sequencing of cancer genomes allows acquisition of complete catalogues of all classes of somatic mutation present in cancer. These mutation catalogues will allow identification of the somatically mutated cancer genes that are operative and characterise patterns of somatic mutation that may reflect previous exogenous and endogenous mutagenic exposures. In this application, we aim to perform whole genome sequencing on 10 chordoma matched genome pairs. RNA Sequencing/Methylation and SNP6 and an additional sequencing of three cancer cell lines will be added to this work.
Project description:The impact of different carcinogenic exposures on the specific patterns of somatic mutations in human tumors remains unclear. To clarify this issue, we profiled 209 cholangiocarcinomas (CCAs) from Asia and Europe, including 108 cases caused by liver fluke Opisthorchis viverrini (OV)-infection and 101 cases due to non-OV etiologies. Whole-exome (N = 15) and prevalence screening (N = 194) revealed recurrent somatic mutations in BAP1 and ARID1A, neither of which has been previously reported to be mutated in CCA. Comparisons between intrahepatic OV and non-OV CCAs demonstrated statistically significant different mutation patterns: BAP1 and IDH1/2 were more frequently mutated in non-OV CCAs, while TP53 displayed the reciprocal pattern. Functional studies demonstrated tumor suppressive roles of BAP1 and ARID1A, establishing the role of chromatin modulators in CCA pathogenesis. These findings indicate that different causative etiologies may induce distinct somatic alterations even within the same tumor type.
Project description:Somatic hotspot mutations and structural amplifications and fusions affecting fibroblast growth factor receptor 2 (FGFR2) occur in multiple cancer types. However, clinical responses to FGFR inhibitors (FGFRi) have remained variable, emphasizing a need to better understand which FGFR2 alterations are oncogenic and targetable. Here we applied transposon-based screening and tumor modelling in mice to uncover truncation of exon (E) 18 of Fgfr2 as a potent driver mutation. Human oncogenomic datasets revealed a diverse set of FGFR2 alterations, including rearrangements (REs), E1-E17 partial amplifications, and E18 nonsense and frameshift mutations, each causing transcription of E18-truncated FGFR2 (FGFR2deltaE18). Somatic modelling in mice and human tumor cell lines using a compendium of FGFR2deltaE18 and full-length variants identified FGFR2deltaE18-truncation as potent single-driver alteration in cancer. Here we show the phosphoproteomic landscape of FGFR2 variants in murine epithelial cell (MEC) lines and mouse tumors. Global (STY) phosphoproteomics using IMAC and phosphotyrosine phosphoproteomics using pTyr IP’s are combined with DIA protein expression data to uncover oncogenic signaling of clinically-relevant FGFR2 variants.
Project description:Alterations of the tumor suppressor TP53, one of the most common events in cancer, alone are insufficient for tumor development but serve as drivers of transformation. We sought to identify cooperating events through genomic analyses of a novel somatic Trp53R245W mouse model (equivalent to the TP53R248W hot spot mutation in human cancers) that recapitulates metastatic breast cancer development. We identified cooperating lesions similar to those found in human breast cancers. Moreover, we identified activation of the Pi3k/Akt/mTOR pathway in most tumors via mutations in Pten, Erbb2, Kras and/or a recurrent Pip5k1c mutation that stabilizes the Pip5k1c protein to activate Pi3k/Akt/mTOR signaling. Another PIP5K1C family member, PIP5K1A, is co-amplified with PI4KB in 18% of human breast cancer patients and both encode kinases that are responsible for production of the PI3K substrate, phosphatidylinositol 4,5-bisphosphate. Thus, the TP53R248W mutation and PI3K/Akt/mTOR signaling are major cooperative events driving breast cancer development. Additionally, we demonstrated that the upregulation of oxidative phosphorylation by Pi3k/Akt/mTOR signaling is a vulnerability in murine as well as human breast cancer cell lines. These findings advance our understanding of mutant p53-driven breast tumors and expand testable targets for breast cancer treatment.
Project description:<p>The HER pathway is the driving force behind 30% of human breast cancers. It is important to understand how targeted therapies block different cellular pathways, and mechanisms of escape from this blockage. Therapies directed at HER2 establish a successful treatment paradigm, but de novo and acquired resistance exist. The HER signaling system is a complex network with four receptors and eleven ligands, a phosphorylation signaling cascade, and many transcription factors, all complicated by both positive and negative feedback circuits. Analysis of genomes, exomes and transcriptomes by next generation sequencing is aimed at uncovering the genetic factors responsible for patient responses to HER2-directed therapies.</p> <p>We are sequencing HER2-overexpressing cancers, in order to identify potential somatic changes that may better select patients who will benefit from therapy, to determine new targets that may overcome resistance, and to improve outcomes with known current HER2-targeted therapies. Whole exome capture sequencing will determine somatic mutation profiles in HER2-overexpressing tumors, to comprehensively characterize the somatic alterations, with the goal of identifying those patients most likely to respond, as well as discovering new targets that may overcome resistance to HER2-directed therapy. We augment the whole exome data with RNA-seq data to determine expression levels of somatic mutations we discover. </p>
Project description:It is now well understood that epigenetic alterations occur frequently in sporadic breast carcinogenesis, but little is known about the epigenetic alterations associated with familial breast tumors. We performed genome-wide DNA methylation profiling on familial breast cancers (n=33) to identify patterns of methylation specific to the different mutation groups (BRCA1, BRCA2 and BRCAx) or intrinsic subtypes of breast cancer (basal, luminal A, luminal B, HER2 and normal-like). We used methylated DNA immunoprecipitation (meDIP) on Affymetrix human promoter chips to interrogate methylation profiles across 25,500 distinct transcripts.
Project description:The impact of different carcinogenic exposures on the specific patterns of somatic mutations in human tumors remains unclear. To clarify this issue, we profiled 209 cholangiocarcinomas (CCAs) from Asia and Europe, including 108 cases caused by liver fluke Opisthorchis viverrini (OV)-infection and 101 cases due to non-OV etiologies. Whole-exome (N = 15) and prevalence screening (N = 194) revealed recurrent somatic mutations in BAP1 and ARID1A, neither of which has been previously reported to be mutated in CCA. Comparisons between intrahepatic OV and non-OV CCAs demonstrated statistically significant different mutation patterns: BAP1 and IDH1/2 were more frequently mutated in non-OV CCAs, while TP53 displayed the reciprocal pattern. Functional studies demonstrated tumor suppressive roles of BAP1 and ARID1A, establishing the role of chromatin modulators in CCA pathogenesis. These findings indicate that different causative etiologies may induce distinct somatic alterations even within the same tumor type. Illumina 450k methylation array profiling performed on wild-type (n=23) and mutant (n=9) CCA (cholangiocarcinoma) samples, with adjacent normal tissue (n=4)