Cancers arise owing to mutations in a subset of genes that confer growth advantage. The availability of the human genome sequence led us to propose that systematic resequencing of cancer genomes for mutations would lead to the discovery of many additional cancer genes. Here we report more than 1,000 somatic mutations found in 274 megabases (Mb) of DNA ©2007 Nature Publishing Group Correspondence and requests for materials should be addressed to P. A.F. (paf@sanger.ac.uk) or M.R.S. (mrs@sanger.ac.uk).. Supplementary Information is linked to the online version of the paper at www.nature.com/nature.Reprints and permissions information is available at www.nature.com/reprints.The authors declare no competing financial interests. Europe PMC Funders GroupAuthor Manuscript Nature. Author manuscript; available in PMC 2009 July 20. Europe PMC Funders Author ManuscriptsEurope PMC Funders Author Manuscripts corresponding to the coding exons of 518 protein kinase genes in 210 diverse human cancers. There was substantial variation in the number and pattern of mutations in individual cancers reflecting different exposures, DNA repair defects and cellular origins. Most somatic mutations are likely to be 'passengers' that do not contribute to oncogenesis. However, there was evidence for 'driver' mutations contributing to the development of the cancers studied in approximately 120 genes. Systematic sequencing of cancer genomes therefore reveals the evolutionary diversity of cancers and implicates a larger repertoire of cancer genes than previously anticipated.Cancers are clonal proliferations that arise owing to mutations that confer selective growth advantage on cells. The mutated genes that are causally implicated in cancer development are known as 'cancer genes' and more than 350 have thus far been identified (ref. 1 and http://www.sanger.ac.uk/genetics/CGP/Census/). Cancer genes have been identified by several different physical and genetic mapping strategies, by biological assays and as plausible biological candidates. Each of these approaches has identified a subset of cancer genes, leaving the possibility that others have been overlooked. The provision of the human genome sequence, therefore, led to the proposal that systematic resequencing of cancer genomes could reveal the full compendium of mutations in individual cancers and hence identify many of the remaining cancer genes2.Somatic mutations occur in the genomes of all dividing cells, both normal and neoplastic. They may occur as a result of misincorporation during DNA replication or through exposure to exogenous or endogenous mutagens. Cancer genomes carry two biological classes of somatic mutation arising from these various processes. 'Driver' mutations confer growth advantage on the cell in which they occur, are causally implicated in cancer development and have therefore been positively selected. By definition, these mutations are in 'cancer genes'. Conversely, 'passenger' mutations have not been subject to selection. They were present in the cell that wa...

SummaryThe genetics of renal cancer is dominated by inactivation of the VHL tumour suppressor gene in clear cell carcinoma (ccRCC), the commonest histological subtype. A recent large-scale screen of ~3500 genes by PCR-based exon re-sequencing identified several new cancer genes in ccRCC including UTX (KDM6A)1, JARID1C (KDM5C) and SETD22. These genes encode enzymes that demethylate (UTX, JARID1C) or methylate (SETD2) key lysine residues of histone H3. Modification of the methylation state of these lysine residues of histone H3 regulates chromatin structure and is implicated in transcriptional control3. However, together these mutations are present in fewer than 15% of ccRCC, suggesting the existence of additional, currently unidentified cancer genes. Here, we have sequenced the protein coding exome in a series of primary ccRCC and report the identification of the SWI/SNF chromatin remodeling complex gene PBRM14 as a second major ccRCC cancer gene, with truncating mutations in 41% (92/227) of cases. These data further elucidate the somatic genetic architecture of ccRCC and emphasize the marked contribution of aberrant chromatin biology.

Clear cell renal cell carcinoma (ccRCC) is the most common form of adult kidney cancer, characterised by the presence of inactivating mutations in the VHL gene in the majority of cases1,2 and by infrequent somatic mutations in known cancer genes. To elucidate further the genetics of ccRCC, we have sequenced 101 cases through 3544 protein coding genes. Here we report the identification of inactivating mutations in two genes encoding enzymes involved in histone modification, SETD2, a histone H3 lysine 36 methyltransferase and JARID1C (KDM5C), a histone H3 lysine 4 demethylase in addition to mutations in the histone H3 lysine 27 demethylase, UTX (KMD6A), we recently reported3. The results highlight the role of mutations in components of the chromatin modification machinery in human cancer. Additionally, NF2 mutations were found in non-VHL mutated ccRCC and several other likely cancer genes were identified. These results indicate that substantial genetic heterogeneity exists in a cancer type dominated by mutations in a single gene and that systematic screens will be key to fully elucidating the somatic genetic architecture of cancer.

The cancer genome is moulded by the dual processes of somatic mutation and selection. Homozygous deletions in cancer genomes occur over recessive cancer genes, where they can confer selective growth advantage, and over fragile sites, where they are thought to reflect an increased local rate of DNA breakage. However, most homozygous deletions in cancer genomes are unexplained. Here we identified 2,428 somatic homozygous deletions in 746 cancer cell lines. These overlie 11% of protein-coding genes that, therefore, are not mandatory for survival of human cells. We derived structural signatures that distinguish between homozygous deletions over recessive cancer genes and fragile sites. Application to clusters of unexplained homozygous deletions suggests that many are in regions of inherent fragility, whereas a small subset overlies recessive cancer genes. The results illustrate how structural signatures can be used to distinguish between the influences of mutation and selection in cancer genomes. The extensive copy number, genotyping, sequence and expression data available for this large series of publicly available cancer cell lines renders them informative reagents for future studies of cancer biology and drug discovery.

Somatically acquired epigenetic changes are present in many cancers. Epigenetic regulation is maintained via post-translational modifications of core histones. Here, we describe inactivating somatic mutations in the histone lysine demethylase, UTX, pointing to histone H3 lysine methylation deregulation in multiple tumour types. UTX reintroduction into cancer cells with inactivating UTX mutations resulted in slowing of proliferation and marked transcriptional changes. These data identify UTX as a new human cancer gene.

An activating point mutation in codon 12 of the HRAS gene was the first somatic point mutation identified in a human cancer and established the role of somatic mutations as the common driver of oncogenesis. Since then, there have been over 11,000 mutations in the three RAS (HRAS, KRAS and NRAS) genes in codons 12, 13 and 61 reported in the literature. We report here the identification of recurrent somatic missense mutations at alanine 146, a highly conserved residue in the guanine nucleotide binding domain. In two independent series of colorectal cancers from Hong Kong and the United States we detected KRAS A146 mutations in 7/126 and 2/94 cases, respectively, giving a combined frequency of 4%. We also detected KRAS A146 mutations in 2/40 (5%) colorectal cell lines, including the NCI-60 colorectal cancer line HCC2998. Codon 146 mutations thus are likely to make an equal or greater contribution to colorectal cancer than codon 61 mutations (4.2% in our combined series, 1% in the literature). Lung adenocarcinomas and large cell carcinomas did not show codon 146 mutations. We did, however, identify a KRAS A146 mutation in the ML-2 acute myeloid leukemia cell line and an NRAS A146 mutation in the NALM-6 B-cell acute lymphoblastic leukemia line, suggesting that the contribution of codon 146 mutations is not entirely restricted to colorectal cancers or to KRAS.

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We have previously shown that GAA trinucleotide repeats have undergone significant expansion in the human genome. Here we present the analysis of the length distribution of all 10 nonredundant trinucleotide repeat motifs in 20 complete eukaryotic genomes (6 mammalian, 2 nonmammalian vertebrates, 4 arthropods, 4 fungi, and 1 each of nematode, amoebozoa, alveolate, and plant), which showed that the abundance of large expansions of GAA trinucleotide repeats is specific to mammals. Analysis of human-chimpanzee-gorilla orthologs revealed that loci with large expansions are species-specific and have occurred after divergence from the common ancestor. PCR analysis of human controls revealed large expansions at multiple human (GAA)(30+) loci; nine loci showed expanded alleles containing >65 triplets, analogous to disease-causing expansions in Friedreich ataxia, including two that are in introns of genes of unknown function. The abundance of long GAA trinucleotide repeat tracts in mammalian genomes represents a significant mutation potential and source of interindividual variability.