PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-23 (23)
 

Clipboard (0)
None

Select a Filter Below

Year of Publication
Document Types
1.  Integrated Analysis of Germline and Somatic Variants in Ovarian Cancer 
Nature communications  2014;5:3156.
We report the first large-scale exome-wide analysis of the combined germline-somatic landscape in ovarian cancer. Here we analyze germline and somatic alterations in 429 ovarian carcinoma cases and 557 controls. We identify 3,635 high confidence, rare truncation and 22,953 missense variants with predicted functional impact. We find germline truncation variants and large deletions across Fanconi pathway genes in 20% of cases. Enrichment of rare truncations is shown in BRCA1, BRCA2, and PALB2. Additionally, we observe germline truncation variants in genes not previously associated with ovarian cancer susceptibility (NF1, MAP3K4, CDKN2B, and MLL3). Evidence for loss of heterozygosity was found in 100% and 76% of cases with germline BRCA1 and BRCA2 truncations respectively. Germline-somatic interaction analysis combined with extensive bioinformatics annotation identifies 237 candidate functional germline truncation and missense variants, including 2 pathogenic BRCA1 and 1 TP53 deleterious variants. Finally, integrated analyses of germline and somatic variants identify significantly altered pathways, including the Fanconi, MAPK, and MLL pathways.
doi:10.1038/ncomms4156
PMCID: PMC4025965  PMID: 24448499
2.  BreakTrans: uncovering the genomic architecture of gene fusions 
Genome Biology  2013;14(8):R87.
Producing gene fusions through genomic structural rearrangements is a major mechanism for tumor evolution. Therefore, accurately detecting gene fusions and the originating rearrangements is of great importance for personalized cancer diagnosis and targeted therapy. We present a tool, BreakTrans, that systematically maps predicted gene fusions to structural rearrangements. Thus, BreakTrans not only validates both types of predictions, but also provides mechanistic interpretations. BreakTrans effectively validates known fusions and discovers novel events in a breast cancer cell line. Applying BreakTrans to 43 breast cancer samples in The Cancer Genome Atlas identifies 90 genomically validated gene fusions. BreakTrans is available at http://bioinformatics.mdanderson.org/main/BreakTrans
doi:10.1186/gb-2013-14-8-r87
PMCID: PMC4054677  PMID: 23972288
3.  The origin and evolution of mutations in Acute Myeloid Leukemia 
Cell  2012;150(2):264-278.
Summary
Most mutations in cancer genomes are thought to be acquired after the initiating event, which may cause genomic instability, driving clonal evolution. However, for acute myeloid leukemia (AML), normal karyotypes are common, and genomic instability is unusual. To better understand clonal evolution in AML, we sequenced the genomes of AML samples with a known initiating event (PML-RARA) vs. normal karyotype AML samples, and the exomes of hematopoietic stem/progenitor cells (HSPCs) from healthy people. Collectively, the data suggest that most of the mutations found in AML genomes are actually random events that occurred in HSPCs before they acquired the initiating mutation; the mutational history of that cell is “captured” as the clone expands. In many cases, only one or two additional, cooperating mutations are needed to generate the malignant founding clone. Cells from the founding clone can acquire additional cooperating mutations, yielding subclones that can contribute to disease progression and/or relapse.
doi:10.1016/j.cell.2012.06.023
PMCID: PMC3407563  PMID: 22817890
4.  Background mutations in parental cells account for most of the genetic heterogeneity of Induced Pluripotent Stem Cells 
Cell Stem Cell  2012;10(5):570-582.
Summary
To assess the genetic consequences of induced Pluripotent Stem Cell (iPSC) reprogramming, we sequenced the genomes of ten murine iPSC clones derived from three independent reprogramming experiments, and compared them to their parental cell genomes. We detected hundreds of single nucleotide variants (SNVs) in every clone, with an average of 11 in coding regions. In two experiments, all SNVs were unique for each clone and did not cluster in pathways, but in the third, all four iPSC clones contained 157 shared genetic variants, which could also be detected in rare cells (<1 in 500) within the parental MEF pool. This data suggests that most of the genetic variation in iPSC clones is not caused by reprogramming per se, but is rather a consequence of cloning individual cells, which “captures” their mutational history. These findings have implications for the development and therapeutic use of cells that are reprogrammed by any method.
doi:10.1016/j.stem.2012.03.002
PMCID: PMC3348423  PMID: 22542160
5.  A rapid and robust method for selective isotope labeling of proteins 
Methods (San Diego, Calif.)  2011;55(4):370-378.
Amino-acid selective isotope labeling of proteins offers numerous advantages in mechanistic studies by revealing structural and functional information unattainable from a crystallographic approach. However, efficient labeling of proteins with selected amino acids necessitates auxotrophic hosts, which are often not available. We have constructed a set of auxotrophs in a commonly used Escherichia coli expression strain C43(DE3), a derivative of E. coli BL21(DE3), which can be used for isotopic labeling of individual amino acids or sets of amino acids. These strains have general applicability to either soluble or membrane proteins that can be expressed in E. coli. We present examples in which proteins are selectively labeled with 13C- and 15N-amino acids and studied using magic-angle spinning solid-state NMR and pulsed EPR, demonstrating the utility of these strains for biophysical characterization of membrane proteins, radical-generating enzymes and metalloproteins.
doi:10.1016/j.ymeth.2011.08.019
PMCID: PMC3261321  PMID: 21925267
isotope; auxotroph; E. coli; protein expression; NMR; EPR
6.  Clonal Architecture of Secondary Acute Myeloid Leukemia 
The New England Journal of Medicine  2012;366(12):1090-1098.
BACKGROUND
The myelodysplastic syndromes are a group of hematologic disorders that often evolve into secondary acute myeloid leukemia (AML). The genetic changes that underlie progression from the myelodysplastic syndromes to secondary AML are not well understood.
METHODS
We performed whole-genome sequencing of seven paired samples of skin and bone marrow in seven subjects with secondary AML to identify somatic mutations specific to secondary AML. We then genotyped a bone marrow sample obtained during the antecedent myelodysplastic-syndrome stage from each subject to determine the presence or absence of the specific somatic mutations. We identified recurrent mutations in coding genes and defined the clonal architecture of each pair of samples from the myelodysplastic-syndrome stage and the secondary-AML stage, using the allele burden of hundreds of mutations.
RESULTS
Approximately 85% of bone marrow cells were clonal in the myelodysplastic-syndrome and secondary-AML samples, regardless of the myeloblast count. The secondary-AML samples contained mutations in 11 recurrently mutated genes, including 4 genes that have not been previously implicated in the myelodysplastic syndromes or AML. In every case, progression to acute leukemia was defined by the persistence of an antecedent founding clone containing 182 to 660 somatic mutations and the outgrowth or emergence of at least one subclone, harboring dozens to hundreds of new mutations. All founding clones and subclones contained at least one mutation in a coding gene.
CONCLUSIONS
Nearly all the bone marrow cells in patients with myelodysplastic syndromes and secondary AML are clonally derived. Genetic evolution of secondary AML is a dynamic process shaped by multiple cycles of mutation acquisition and clonal selection. Recurrent gene mutations are found in both founding clones and daughter subclones. (Funded by the National Institutes of Health and others.)
doi:10.1056/NEJMoa1106968
PMCID: PMC3320218  PMID: 22417201
7.  Clonal evolution in relapsed acute myeloid leukemia revealed by whole genome sequencing 
Nature  2012;481(7382):506-510.
Summary
Most patients with acute myeloid leukemia (AML) die from progressive disease after relapse, which is associated with clonal evolution at the cytogenetic level1,2. To determine the mutational spectrum associated with relapse, we sequenced the primary tumor and relapse genomes from 8 AML patients, and validated hundreds of somatic mutations using deep sequencing; this allowed us to precisely define clonality and clonal evolution patterns at relapse. Besides discovering novel, recurrently mutated genes (e.g. WAC, SMC3, DIS3, DDX41, and DAXX) in AML, we found two major clonal evolution patterns during AML relapse: 1) the founding clone in the primary tumor gained mutations and evolved into the relapse clone, or 2) a subclone of the founding clone survived initial therapy, gained additional mutations, and expanded at relapse. In all cases, chemotherapy failed to eradicate the founding clone. The comparison of relapse-specific vs. primary tumor mutations in all 8 cases revealed an increase in transversions, probably due to DNA damage caused by cytotoxic chemotherapy. These data demonstrate that AML relapse is associated with the addition of new mutations and clonal evolution, which is shaped in part by the chemotherapy that the patients receive to establish and maintain remissions.
doi:10.1038/nature10738
PMCID: PMC3267864  PMID: 22237025
8.  RECURRENT MUTATIONS IN THE U2AF1 SPLICING FACTOR IN MYELODYSPLASTIC SYNDROMES 
Nature Genetics  2011;44(1):53-57.
Myelodysplastic syndromes (MDS) are hematopoietic stem cell disorders that often progress to chemotherapy-resistant secondary acute myeloid leukemia (sAML). We used whole genome sequencing to perform an unbiased comprehensive screen to discover all the somatic mutations in a sAML sample and genotyped these loci in the matched MDS sample. Here we show that a missense mutation affecting the serine at codon 34 (S34) in U2AF1 was recurrently mutated in 13/150 (8.7%) de novo MDS patients, with suggestive evidence of an associated increased risk of progression to sAML. U2AF1 is a U2 auxiliary factor protein that recognizes the AG splice acceptor dinucleotide at the 3′ end of introns and mutations are located in highly conserved zinc fingers in U2AF11,2. Mutant U2AF1 promotes enhanced splicing and exon skipping in reporter assays in vitro. This novel, recurrent mutation in U2AF1 implicates altered pre-mRNA splicing as a potential mechanism for MDS pathogenesis.
doi:10.1038/ng.1031
PMCID: PMC3247063  PMID: 22158538
9.  Recurrent DNMT3A Mutations in Patients with Myelodysplastic Syndromes 
Alterations in DNA methylation have been implicated in the pathogenesis of myelodysplastic syndromes (MDS), although the underlying mechanism remains largely unknown. Methylation of CpG dinucleotides is mediated by DNA methyltransferases, including DNMT1, DNMT3A, and DNMT3B. DNMT3A mutations have recently been reported in patients with de novo acute myeloid leukemia (AML), providing a rationale for examining the status of DNMT3A in MDS samples. Here, we report the frequency of DNMT3A mutations in patients with de novo MDS, and their association with secondary AML. We sequenced all coding exons of DNMT3A using DNA from bone marrow and paired normal cells from 150 patients with MDS and identified 13 heterozygous mutations with predicted translational consequences in 12/150 patients (8.0%). Amino acid R882, located in the methyltransferase domain of DNMT3A, was the most common mutation site, accounting for 4/13 mutations. DNMT3A mutations were expressed in the majority of cells in all tested mutant samples regardless of blast counts, suggesting that DNMT3A mutations occur early in the course of MDS. Patients with DNMT3A mutations had worse overall survival compared to patients without DNMT3A mutations (p=0.005) and more rapid progression to AML (p=0.007), suggesting that DNMT3A mutation status may have prognostic value in de novo MDS.
doi:10.1038/leu.2011.44
PMCID: PMC3202965  PMID: 21415852
myelodysplastic syndrome; DNMT3A; mutation
10.  Recurring Mutations Found by Sequencing an Acute Myeloid Leukemia Genome 
The New England journal of medicine  2009;361(11):1058-1066.
BACKGROUND
The full complement of DNA mutations that are responsible for the pathogenesis of acute myeloid leukemia (AML) is not yet known.
METHODS
We used massively parallel DNA sequencing to obtain a very high level of coverage (approximately 98%) of a primary, cytogenetically normal, de novo genome for AML with minimal maturation (AML-M1) and a matched normal skin genome.
RESULTS
We identified 12 acquired (somatic) mutations within the coding sequences of genes and 52 somatic point mutations in conserved or regulatory portions of the genome. All mutations appeared to be heterozygous and present in nearly all cells in the tumor sample. Four of the 64 mutations occurred in at least 1 additional AML sample in 188 samples that were tested. Mutations in NRAS and NPM1 had been identified previously in patients with AML, but two other mutations had not been identified. One of these mutations, in the IDH1 gene, was present in 15 of 187 additional AML genomes tested and was strongly associated with normal cytogenetic status; it was present in 13 of 80 cytogenetically normal samples (16%). The other was a nongenic mutation in a genomic region with regulatory potential and conservation in higher mammals; we detected it in one additional AML tumor. The AML genome that we sequenced contains approximately 750 point mutations, of which only a small fraction are likely to be relevant to pathogenesis.
CONCLUSIONS
By comparing the sequences of tumor and skin genomes of a patient with AML-M1, we have identified recurring mutations that may be relevant for pathogenesis.
doi:10.1056/NEJMoa0903840
PMCID: PMC3201812  PMID: 19657110
11.  DNMT3A Mutations in Acute Myeloid Leukemia 
The New England journal of medicine  2010;363(25):2424-2433.
BACKGROUND
The genetic alterations responsible for an adverse outcome in most patients with acute myeloid leukemia (AML) are unknown.
METHODS
Using massively parallel DNA sequencing, we identified a somatic mutation in DNMT3A, encoding a DNA methyltransferase, in the genome of cells from a patient with AML with a normal karyotype. We sequenced the exons of DNMT3A in 280 additional patients with de novo AML to define recurring mutations.
RESULTS
A total of 62 of 281 patients (22.1%) had mutations in DNMT3A that were predicted to affect translation. We identified 18 different missense mutations, the most common of which was predicted to affect amino acid R882 (in 37 patients). We also identified six frameshift, six nonsense, and three splice-site mutations and a 1.5-Mbp deletion encompassing DNMT3A. These mutations were highly enriched in the group of patients with an intermediate-risk cytogenetic profile (56 of 166 patients, or 33.7%) but were absent in all 79 patients with a favorable-risk cytogenetic profile (P<0.001 for both comparisons). The median overall survival among patients with DNMT3A mutations was significantly shorter than that among patients without such mutations (12.3 months vs. 41.1 months, P<0.001). DNMT3A mutations were associated with adverse outcomes among patients with an intermediate-risk cytogenetic profile or FLT3 mutations, regardless of age, and were independently associated with a poor outcome in Cox proportional-hazards analysis.
CONCLUSIONS
DNMT3A mutations are highly recurrent in patients with de novo AML with an intermediate-risk cytogenetic profile and are independently associated with a poor outcome. (Funded by the National Institutes of Health and others.)
doi:10.1056/NEJMoa1005143
PMCID: PMC3201818  PMID: 21067377
12.  The identification of a novel TP53 cancer susceptibility mutation through whole genome sequencing of a patient with therapy-related AML 
Context
The identification of patients with inherited cancer susceptibility syndromes facilitates early diagnosis, prevention, and treatment. However, in many cases of suspected cancer susceptibility, the family history is unclear and genetic testing of common cancer susceptibility genes is unrevealing.
Objective
To apply whole-genome sequencing to a patient with suspected cancer susceptibility (and lacking a clear family history of cancer and no BRCA1 and BRCA2 mutations) to identify rare or novel germline variants in cancer susceptibility genes.
Design, Setting, and Participant
Skin (normal) and bone marrow (leukemia) DNA were obtained from a patient with early-onset breast and ovarian cancer and therapy-related acute myeloid leukemia (t-AML), and analyzed with: 1) whole genome sequencing using paired end reads; 2) SNP genotyping; 3) RNA expression profiling; and 4) spectral karyotyping.
Main Outcome Measures
Structural variants, copy number alterations, single nucleotide variants and small insertions and deletions (indels) were detected and validated using the above platforms.
Results
Whole genome sequencing revealed a novel, heterozygous 3 Kb deletion removing exons 7-9 of TP53 in the patient’s normal skin DNA, which was homozygous in the leukemia DNA as a result of uniparental disomy. In addition, a total of 28 validated somatic single nucleotide variations or indels in coding genes, 8 somatic structural variants, and 12 somatic copy number alterations were detected in the patient’s leukemia genome.
Conclusions
Whole genome sequencing can identify novel, cryptic variants in cancer susceptibility genes in addition to providing unbiased information on the spectrum of mutations in a cancer genome.
doi:10.1001/jama.2011.473
PMCID: PMC3170052  PMID: 21505135
13.  Use of whole genome sequencing to diagnose a cryptic fusion oncogene 
Context
Whole genome sequencing (WGS) is becoming increasingly available for research purposes, but it has not yet been routinely used for clinical diagnosis.
Object
To determine whether whole genome sequencing can identify cryptic, actionable mutations in a clinically relevant time frame.
Design, Setting, and Patient
We were referred a difficult diagnostic case of acute promyelocytic leukemia with no pathogenic X-RARA fusion identified by routine metaphase cytogenetics or interphase FISH. The patient was enrolled in an IRB approved protocol, with consent specifically tailored to the implications of whole genome sequencing. The protocol employs a ‘movable firewall,’ which maintains patient anonymity within the entire research team, but allows the research team to communicate medically relevant information to the treating physician.
Main Outcome Measure
Clinical relevance of whole genome sequencing and time to communicate validated results to the treating physician.
Results
Massively parallel paired-end sequencing allowed us to identify a cytogenetically cryptic event: 77 kilobases from chromosome 15 was inserted en bloc into the second intron of the RARA gene on chromosome 17, resulting in a classic bcr3 PML-RARA fusion gene. RT-PCR subsequently validated the expression of the fusion transcript. Novel FISH probes identified two additional cases of t(15;17)-negative acute promyelocytic leukemia that had cytogenetically invisible insertions. Whole genome sequencing and validation were completed in seven weeks, and changed the treatment plan for the patient.
Conclusions
Whole genome sequencing can identify cytogenetically invisible oncogenes in a clinically relevant timeframe.
doi:10.1001/jama.2011.497
PMCID: PMC3156695  PMID: 21505136
14.  Comparative and demographic analysis of orangutan genomes 
Locke, Devin P. | Hillier, LaDeana W. | Warren, Wesley C. | Worley, Kim C. | Nazareth, Lynne V. | Muzny, Donna M. | Yang, Shiaw-Pyng | Wang, Zhengyuan | Chinwalla, Asif T. | Minx, Pat | Mitreva, Makedonka | Cook, Lisa | Delehaunty, Kim D. | Fronick, Catrina | Schmidt, Heather | Fulton, Lucinda A. | Fulton, Robert S. | Nelson, Joanne O. | Magrini, Vincent | Pohl, Craig | Graves, Tina A. | Markovic, Chris | Cree, Andy | Dinh, Huyen H. | Hume, Jennifer | Kovar, Christie L. | Fowler, Gerald R. | Lunter, Gerton | Meader, Stephen | Heger, Andreas | Ponting, Chris P. | Marques-Bonet, Tomas | Alkan, Can | Chen, Lin | Cheng, Ze | Kidd, Jeffrey M. | Eichler, Evan E. | White, Simon | Searle, Stephen | Vilella, Albert J. | Chen, Yuan | Flicek, Paul | Ma, Jian | Raney, Brian | Suh, Bernard | Burhans, Richard | Herrero, Javier | Haussler, David | Faria, Rui | Fernando, Olga | Darré, Fleur | Farré, Domènec | Gazave, Elodie | Oliva, Meritxell | Navarro, Arcadi | Roberto, Roberta | Capozzi, Oronzo | Archidiacono, Nicoletta | Valle, Giuliano Della | Purgato, Stefania | Rocchi, Mariano | Konkel, Miriam K. | Walker, Jerilyn A. | Ullmer, Brygg | Batzer, Mark A. | Smit, Arian F. A. | Hubley, Robert | Casola, Claudio | Schrider, Daniel R. | Hahn, Matthew W. | Quesada, Victor | Puente, Xose S. | Ordoñez, Gonzalo R. | López-Otín, Carlos | Vinar, Tomas | Brejova, Brona | Ratan, Aakrosh | Harris, Robert S. | Miller, Webb | Kosiol, Carolin | Lawson, Heather A. | Taliwal, Vikas | Martins, André L. | Siepel, Adam | RoyChoudhury, Arindam | Ma, Xin | Degenhardt, Jeremiah | Bustamante, Carlos D. | Gutenkunst, Ryan N. | Mailund, Thomas | Dutheil, Julien Y. | Hobolth, Asger | Schierup, Mikkel H. | Chemnick, Leona | Ryder, Oliver A. | Yoshinaga, Yuko | de Jong, Pieter J. | Weinstock, George M. | Rogers, Jeffrey | Mardis, Elaine R. | Gibbs, Richard A. | Wilson, Richard K.
Nature  2011;469(7331):529-533.
“Orangutan” is derived from the Malay term “man of the forest” and aptly describes the Southeast Asian great apes native to Sumatra and Borneo. The orangutan species, Pongo abelii (Sumatran) and Pongo pygmaeus (Bornean), are the most phylogenetically distant great apes from humans, thereby providing an informative perspective on hominid evolution. Here we present a Sumatran orangutan draft genome assembly and short read sequence data from five Sumatran and five Bornean orangutan genomes. Our analyses reveal that, compared to other primates, the orangutan genome has many unique features. Structural evolution of the orangutan genome has proceeded much more slowly than other great apes, evidenced by fewer rearrangements, less segmental duplication, a lower rate of gene family turnover and surprisingly quiescent Alu repeats, which have played a major role in restructuring other primate genomes. We also describe the first primate polymorphic neocentromere, found in both Pongo species, emphasizing the gradual evolution of orangutan genome structure. Orangutans have extremely low energy usage for a eutherian mammal1, far lower than their hominid relatives. Adding their genome to the repertoire of sequenced primates illuminates new signals of positive selection in several pathways including glycolipid metabolism. From the population perspective, both Pongo species are deeply diverse; however, Sumatran individuals possess greater diversity than their Bornean counterparts, and more species-specific variation. Our estimate of Bornean/Sumatran speciation time, 400k years ago (ya), is more recent than most previous studies and underscores the complexity of the orangutan speciation process. Despite a smaller modern census population size, the Sumatran effective population size (Ne) expanded exponentially relative to the ancestral Ne after the split, while Bornean Ne declined over the same period. Overall, the resources and analyses presented here offer new opportunities in evolutionary genomics, insights into hominid biology, and an extensive database of variation for conservation efforts.
doi:10.1038/nature09687
PMCID: PMC3060778  PMID: 21270892
15.  Identification of a CpG Island Methylator Phenotype that Defines a Distinct Subgroup of Glioma 
Cancer cell  2010;17(5):510-522.
Summary
We have profiled promoter DNA methylation alterations in 272 glioblastoma tumors in the context of The Cancer Genome Atlas (TCGA). We found that a distinct subset of samples displays concerted hypermethylation at a large number of loci, indicating the existence of a glioma-CpG Island Methylator Phenotype (G-CIMP). We validated G-CIMP in a set of non-TCGA glioblastomas and low-grade gliomas. G-CIMP tumors belong to the Proneural subgroup, are more prevalent among low-grade gliomas, display distinct copy-number alterations and are tightly associated with IDH1 somatic mutations. Patients with G-CIMP tumors are younger at the time of diagnosis and experience significantly improved outcome. These findings identify G-CIMP as a distinct subset of human gliomas on molecular and clinical grounds.
doi:10.1016/j.ccr.2010.03.017
PMCID: PMC2872684  PMID: 20399149
DNA methylation; glioma; CIMP; IDH1; TCGA
16.  NMR Determination of Protein pKa Values in the Solid State 
Charged residues play an important role in defining key mechanistic features in many biomolecules. Determining the pKa values of large, membrane or fibrillar proteins can be challenging with traditional methods. In this study we show how solid-state NMR is used to monitor chemical shift changes during a pH titration for the small soluble β1 immunoglobulin binding domain of protein G. The chemical shifts of all the amino acids with charged side-chains throughout the uniformly-13C,15N-labeled protein were monitored over several samples varying in pH; pKa values were determined from these shifts for E27, D36, and E42, and the bounds for the pKa of other acidic side-chain resonances were determined. Additionally, this study shows how the calculated pKa values give insights into the crystal packing of the protein.
doi:10.1021/jz1004413
PMCID: PMC2885713  PMID: 20563223
Chemical shift perturbation; GB1; Magic-angle spinning; pKa determination; Solid-state NMR
17.  Sequencing a mouse acute promyelocytic leukemia genome reveals genetic events relevant for disease progression 
The Journal of Clinical Investigation  2011;121(4):1445-1455.
Acute promyelocytic leukemia (APL) is a subtype of acute myeloid leukemia (AML). It is characterized by the t(15;17)(q22;q11.2) chromosomal translocation that creates the promyelocytic leukemia–retinoic acid receptor α (PML-RARA) fusion oncogene. Although this fusion oncogene is known to initiate APL in mice, other cooperating mutations, as yet ill defined, are important for disease pathogenesis. To identify these, we used a mouse model of APL, whereby PML-RARA expressed in myeloid cells leads to a myeloproliferative disease that ultimately evolves into APL. Sequencing of a mouse APL genome revealed 3 somatic, nonsynonymous mutations relevant to APL pathogenesis, of which 1 (Jak1 V657F) was found to be recurrent in other affected mice. This mutation was identical to the JAK1 V658F mutation previously found in human APL and acute lymphoblastic leukemia samples. Further analysis showed that JAK1 V658F cooperated in vivo with PML-RARA, causing a rapidly fatal leukemia in mice. We also discovered a somatic 150-kb deletion involving the lysine (K)-specific demethylase 6A (Kdm6a, also known as Utx) gene, in the mouse APL genome. Similar deletions were observed in 3 out of 14 additional mouse APL samples and 1 out of 150 human AML samples. In conclusion, whole genome sequencing of mouse cancer genomes can provide an unbiased and comprehensive approach for discovering functionally relevant mutations that are also present in human leukemias.
doi:10.1172/JCI45284
PMCID: PMC3069786  PMID: 21436584
18.  Genome Remodeling in a Basal-like Breast Cancer Metastasis and Xenograft 
Nature  2010;464(7291):999-1005.
Massively parallel DNA sequencing technologies provide an unprecedented ability to screen entire genomes for genetic changes associated with tumor progression. Here we describe the genomic analyses of four DNA samples from an African-American patient with basal-like breast cancer: peripheral blood, the primary tumor, a brain metastasis, and a xenograft derived from the primary tumor. The metastasis contained two de novo mutations and a large deletion not present in the primary tumor, and was significantly enriched for 20 shared mutations. The xenograft retained all primary tumor mutations, and displayed a mutation enrichment pattern that paralleled the metastasis (16 of 20 genes). Two overlapping large deletions, encompassing CTNNA1, were present in all three tumor samples. The differential mutation frequencies and structural variation patterns in metastasis and xenograft compared to the primary tumor suggest that secondary tumors may arise from a minority of cells within the primary.
doi:10.1038/nature08989
PMCID: PMC2872544  PMID: 20393555
19.  Crystal Polymorphism of Protein GB1 Examined by Solid-State NMR Spectroscopy and X-ray Diffraction 
The journal of physical chemistry. B  2007;111(51):14362-14369.
The study of micro- or nanocrystalline proteins by magic-angle spinning (MAS) solid-state NMR (SSNMR) gives atomic-resolution insight into structure in cases when single crystals cannot be obtained for diffraction studies. Subtle differences in the local chemical environment around the protein, including the characteristics of the co-solvent and the buffer, determine whether a protein will form single crystals. The impact of these small changes in formulation is also evident in the SSNMR spectra, but leads only to correspondingly subtle changes in the spectra. Here we demonstrate that several formulations of GB1 microcrystals yield very high-quality SSNMR spectra, although only a subset of conditions enable growth of single crystals. We have characterized these polymorphs by X-ray powder diffraction and assigned the SSNMR spectra. Assignments of the 13C and 15N SSNMR chemical shifts confirm that the backbone structure is conserved, indicative of a common protein fold, but sidechain chemical shifts are changed on the surface of the protein, in a manner dependent upon crystal packing and electrostatic interactions with salt in the mother liquor. Our results demonstrate the ability of SSNMR to reveal minor structural differences among crystal polymorphs. This ability has potential practical utility for studying formulation chemistry of industrial and therapeutic proteins, as well as for deriving fundamental insights into the phenomenon of single crystal growth.
doi:10.1021/jp075531p
PMCID: PMC2774121  PMID: 18052145
formulation chemistry; polymorphism; multidimensional; crystal packing; single crystal diffraction; therapeutic proteins
20.  Somatic mutations affect key pathways in lung adenocarcinoma 
Ding, Li | Getz, Gad | Wheeler, David A. | Mardis, Elaine R. | McLellan, Michael D. | Cibulskis, Kristian | Sougnez, Carrie | Greulich, Heidi | Muzny, Donna M. | Morgan, Margaret B. | Fulton, Lucinda | Fulton, Robert S. | Zhang, Qunyuan | Wendl, Michael C. | Lawrence, Michael S. | Larson, David E. | Chen, Ken | Dooling, David J. | Sabo, Aniko | Hawes, Alicia C. | Shen, Hua | Jhangiani, Shalini N. | Lewis, Lora R. | Hall, Otis | Zhu, Yiming | Mathew, Tittu | Ren, Yanru | Yao, Jiqiang | Scherer, Steven E. | Clerc, Kerstin | Metcalf, Ginger A. | Ng, Brian | Milosavljevic, Aleksandar | Gonzalez-Garay, Manuel L. | Osborne, John R. | Meyer, Rick | Shi, Xiaoqi | Tang, Yuzhu | Koboldt, Daniel C. | Lin, Ling | Abbott, Rachel | Miner, Tracie L. | Pohl, Craig | Fewell, Ginger | Haipek, Carrie | Schmidt, Heather | Dunford-Shore, Brian H. | Kraja, Aldi | Crosby, Seth D. | Sawyer, Christopher S. | Vickery, Tammi | Sander, Sacha | Robinson, Jody | Winckler, Wendy | Baldwin, Jennifer | Chirieac, Lucian R. | Dutt, Amit | Fennell, Tim | Hanna, Megan | Johnson, Bruce E. | Onofrio, Robert C. | Thomas, Roman K. | Tonon, Giovanni | Weir, Barbara A. | Zhao, Xiaojun | Ziaugra, Liuda | Zody, Michael C. | Giordano, Thomas | Orringer, Mark B. | Roth, Jack A. | Spitz, Margaret R. | Wistuba, Ignacio I. | Ozenberger, Bradley | Good, Peter J. | Chang, Andrew C. | Beer, David G. | Watson, Mark A. | Ladanyi, Marc | Broderick, Stephen | Yoshizawa, Akihiko | Travis, William D. | Pao, William | Province, Michael A. | Weinstock, George M. | Varmus, Harold E. | Gabriel, Stacey B. | Lander, Eric S. | Gibbs, Richard A. | Meyerson, Matthew | Wilson, Richard K.
Nature  2008;455(7216):1069-1075.
Determining the genetic basis of cancer requires comprehensive analyses of large collections of histopathologically well-classified primary tumours. Here we report the results of a collaborative study to discover somatic mutations in 188 human lung adenocarcinomas. DNA sequencing of 623 genes with known or potential relationships to cancer revealed more than 1,000 somatic mutations across the samples. Our analysis identified 26 genes that are mutated at significantly high frequencies and thus are probably involved in carcinogenesis. The frequently mutated genes include tyrosine kinases, among them the EGFR homologue ERBB4; multiple ephrin receptor genes, notably EPHA3; vascular endothelial growth factor receptor KDR; and NTRK genes. These data provide evidence of somatic mutations in primary lung adenocarcinoma for several tumour suppressor genes involved in other cancers—including NF1, APC, RB1 and ATM—and for sequence changes in PTPRD as well as the frequently deleted gene LRP1B. The observed mutational profiles correlate with clinical features, smoking status and DNA repair defects. These results are reinforced by data integration including single nucleotide polymorphism array and gene expression array. Our findings shed further light on several important signalling pathways involved in lung adenocarcinoma, and suggest new molecular targets for treatment.
doi:10.1038/nature07423
PMCID: PMC2694412  PMID: 18948947
21.  The prevalence of the duodenal ulcer promoting gene (dupA) in Helicobacter pylori isolates varies by ethnic group and is not universally associated with disease development: a case-control study 
Gut Pathogens  2009;1:5.
Background
The putative H. pylori pathogenicity-associated factor dupA has been associated with IL-8 induction in vitro, and duodenal ulcer (DU) and gastric cancer (GC) development in certain populations, but this association is inconsistent between studies. We aimed to investigate dupA prevalence in clinical isolates from Sweden, Australia and from ethnic Chinese, Indians and Malays resident in Malaysia and Singapore and to examine the association with DU and GC. In addition we investigated the sequence diversity between isolates from these diverse groups and compared the level of IL-8 secretion in isolates possessing and lacking dupA.
Methods
PCR primers were designed to amplify over the C/T insertion denoting a continuous dupA. PCR products from 29 clinical isolates were sequenced and compared with sequences from three additional strains obtained from GenBank. Clinical isolates from 21 Malaysian patients (8 dupA-positive, 14 dupA-negative) were assessed for their ability to induce IL-8 in AGS cells in vitro. Statistical analysis was performed using Fisher's exact test.
Results
The prevalence of dupA in isolates from Swedish functional dyspepsia (FD) control patients (65%, 13/20) was higher and in isolates from Indian FD patients (7.1%, 3/42) was lower as compared with isolates from Chinese (28.9%, 13/49, P = 0.005, P = 0.025), Malay (35.7%, 5/14, P = 0.16, P = 0.018) and Australian (37.8%, 17/45, P = 0.060, P < 0.001) FD patients. dupA was associated with DU and GC development in Chinese with 62.5% (10/16) and 54.6% (12/22) of isolates possessing dupA respectively as compared with FD controls (28.9%) (P = 0.015, P = 0.032). No significant difference in prevalence of dupA between FD controls, DU (63.6%, 7/11) and GC (61.9%, 13/21) cases (P = 1.000) was observed in the Swedish population. Sequence analysis revealed a pairwise variation of 1.9% and all isolates possessed the C/T insertion. The average IL-8 induction was 1330 pg/mL for dupA-positive isolates and 1378 pg/mL for dupA-negative isolates.
Conclusion
Although dupA is highly conserved when present, we identified no consistent association between dupA and DU or GC development across the ethnic groups investigated, with the dupA prevalence in control groups varying significantly. Our results would suggest that in the clinical isolates investigated dupA is not associated with IL-8 induction in vitro.
doi:10.1186/1757-4749-1-5
PMCID: PMC2667403  PMID: 19338650
22.  The Role of the Autism Diagnostic Observation Schedule in the Assessment of Autism Spectrum Disorders in School and Community Settings 
Autism diagnostic practices among school and clinical psychologists, particularly those using the Autism Diagnostic Observation Schedule (ADOS), were examined using national survey results (N = 132). School and clinical psychologists were similar in following the Best Practice Guidelines for screening, diagnosis and assessment, School psychologists were more likely to include a school or home observation and teacher report than clinical psychologists but evaluated significantly fewer children with autism spectrum disorders per year compared to clinical psychologists. School psychologists who were ADOS users were more likely to consider themselves autism experts and include a review of records than ADOS non-users. Perceived advantages of the ADOS included its strength in capturing ASD-specific behaviors and the standardized structure provided for observation, while diagnostic discrimination and required resources were the most commonly identified disadvantages.
PMCID: PMC1868476  PMID: 17502922
23.  High-yield expression and purification of isotopically labeled cytochrome P450 monooxygenases for solid-state NMR spectroscopy 
Biochimica et biophysica acta  2007;1768(12):3061-3070.
Cytochrome P450 monooxygenases (P450s), which represent the major group of drug metabolizing enzymes in humans, also catalyze important synthetic and detoxicative reactions in insects, plants and many microbes. Flexibilities in their catalytic sites and membrane associations are thought to play central roles in substrate binding and catalytic specificity. To date, E. coli expression strategies for structural analysis of eukaryotic membrane-bound P450s by X-ray crystallography have necessitated full or partial removal of their N-terminal signal anchor domain (SAD) and, often, replacement of residues more peripherally associated with the membrane (such as the F-G loop region). Even with these modifications, investigations of P450 structural flexibility remain challenging with multiple single crystal conditions needed to identify spatial variations between substrate-free and different substrate-bound forms. To overcome these limitations, we have developed methods for the efficient expression of 13C- and 15N-labeled P450s and analysis of their structures by magic-angle spinning solid-state NMR (SSNMR) spectroscopy. In the presence of co-expressed GroEL and GroES chaperones, full-length (53 kDa) Arabidopsis 13C,15N-labeled CYP98A3 is expressed at yields of 2–4 mg per liter of minimal media without the necessity of generating side chain modifications or N-terminal deletions. Precipitated CYP98A3 generates high quality SSNMR spectra consistent with a homogeneous, folded protein. These data highlight the potential of these methodologies to contribute to the structural analysis of membrane-bound proteins.
doi:10.1016/j.bbamem.2007.09.009
PMCID: PMC2192630  PMID: 18005930
cytochrome P450 monooxygenases (P450s); heterologous expression; membrane proteins; solid; state NMR analysis

Results 1-23 (23)