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1.  The relationship between quantitative human epidermal growth factor receptor 2 gene expression by the 21-gene reverse transcriptase polymerase chain reaction assay and adjuvant trastuzumab benefit in Alliance N9831 
Introduction
The N9831 trial demonstrated the efficacy of adjuvant trastuzumab for patients with human epidermal growth factor receptor 2 (HER2) locally positive tumors by protein or gene analysis. We used the 21-gene assay to examine the association of quantitative HER2 messenger RNA (mRNA) gene expression and benefit from trastuzumab.
Methods
N9831 tested the addition of trastuzumab to chemotherapy in stage I–III HER2-positive breast cancer. For two of the arms of the trial, doxorubicin and cyclophosphamide followed by paclitaxel (AC-T) and doxorubicin and cyclophosphamide followed by paclitaxel and trastuzumab concurrent chemotherapy-trastuzumab (AC-TH), recurrence score (RS) and HER2 mRNA expression were determined by the 21-gene assay (Oncotype DX®) (negative <10.7, equivocal 10.7 to <11.5, and positive ≥11.5 log2 expression units). Cox regression was used to assess the association of HER2 expression with trastuzumab benefit in preventing distant recurrence.
Results
Median follow-up was 7.4 years. Of 1,940 total patients, 901 had consent and sufficient tissue. HER2 by reverse transcriptase polymerase chain reaction (RT-PCR) was negative in 130 (14 %), equivocal in 85 (9 %), and positive in 686 (76 %) patients. Concordance between HER2 assessments was 95 % for RT-PCR versus central immunohistochemistry (IHC) (>10 % positive cells = positive), 91 % for RT-PCR versus central fluorescence in situ hybridization (FISH) (≥2.0 = positive) and 94 % for central IHC versus central FISH. In the primary analysis, the association of HER2 expression by 21-gene assay with trastuzumab benefit was marginally nonsignificant (nonlinear p = 0.057). In hormone receptor-positive patients (local IHC) the association was significant (p = 0.002). The association was nonlinear with the greatest estimated benefit at lower and higher HER2 expression levels.
Conclusions
Concordance among HER2 assessments by central IHC, FISH, and RT-PCR were similar and high. Association of HER2 mRNA expression with trastuzumab benefit as measured by time to distant recurrence was nonsignificant. A consistent benefit of trastuzumab irrespective of mHER2 levels was observed in patients with either IHC-positive or FISH-positive tumors. Trend for benefit was observed also for the small groups of patients with negative results by any or all of the central assays.
Trial registration
Clinicaltrials.gov NCT00005970. Registered 5 July 2000.
Electronic supplementary material
The online version of this article (doi:10.1186/s13058-015-0643-7) contains supplementary material, which is available to authorized users.
doi:10.1186/s13058-015-0643-7
PMCID: PMC4589954  PMID: 26429296
2.  Late-onset Alzheimer disease risk variants mark brain regulatory loci 
Neurology: Genetics  2015;1(2):e15.
Objective:
To investigate the top late-onset Alzheimer disease (LOAD) risk loci detected or confirmed by the International Genomics of Alzheimer's Project for association with brain gene expression levels to identify variants that influence Alzheimer disease (AD) risk through gene expression regulation.
Methods:
Expression levels from the cerebellum (CER) and temporal cortex (TCX) were obtained using Illumina whole-genome cDNA-mediated annealing, selection, extension, and ligation assay (WG-DASL) for ∼400 autopsied patients (∼200 with AD and ∼200 with non-AD pathologies). We tested 12 significant LOAD genome-wide association study (GWAS) index single nucleotide polymorphisms (SNPs) for cis association with levels of 34 genes within ±100 kb. We also evaluated brain levels of 14 LOAD GWAS candidate genes for association with 1,899 cis-SNPs. Significant associations were validated in a subset of TCX samples using next-generation RNA sequencing (RNAseq).
Results:
We identified strong associations of brain CR1, HLA-DRB1, and PILRB levels with LOAD GWAS index SNPs. We also detected other strong cis-SNPs for LOAD candidate genes MEF2C, ZCWPW1, and SLC24A4. MEF2C and SLC24A4, but not ZCWPW1 cis-SNPs, also associate with LOAD risk, independent of the index SNPs. The TCX expression associations could be validated with RNAseq for CR1, HLA-DRB1, ZCWPW1, and SLC24A4.
Conclusions:
Our results suggest that some LOAD GWAS variants mark brain regulatory loci, nominate genes under regulation by LOAD risk variants, and annotate these variants for their brain regulatory effects.
doi:10.1212/NXG.0000000000000012
PMCID: PMC4807909  PMID: 27066552
3.  Recurrent PAX3-MAML3 Fusion in Biphenotypic Sinonasal Sarcoma 
Nature genetics  2014;46(7):666-668.
Biphenotypic sinonasal sarcoma (SNS) is a newly described tumor of the nasal and paranasal areas. Herein, we report the novel recurring chromosomal translocation t(2;4)(q35;q31.1) in SNS. The translocation results in the formation of the fusion protein PAX3-MAML3, which is a potent transcriptional activator of PAX3 response elements. The SNS phenotype is characterized by aberrant expression of genes involved in neuroectodermal and myogenic differentiation, which closely simulates the developmental roles of PAX3.
doi:10.1038/ng.2989
PMCID: PMC4236026  PMID: 24859338
PAX3; MAML3; fusion gene; rearrangement; sinonasal sarcoma
4.  Common Oncogene Mutations and Novel SND1-BRAF Transcript Fusion in Lung Adenocarcinoma from Never Smokers 
Scientific Reports  2015;5:9755.
Lung adenocarcinomas from never smokers account for approximately 15 to 20% of all lung cancers and these tumors often carry genetic alterations that are responsive to targeted therapy. Here we examined mutation status in 10 oncogenes among 89 lung adenocarcinomas from never smokers. We also screened for oncogene fusion transcripts in 20 of the 89 tumors by RNA-Seq. In total, 62 tumors had mutations in at least one of the 10 oncogenes, including EGFR (49 cases, 55%), K-ras (5 cases, 6%), BRAF (4 cases, 5%), PIK3CA (3 cases, 3%), and ERBB2 (4 cases, 5%). In addition to ALK fusions identified by IHC/FISH in four cases, two previously known fusions involving EZR- ROS1 and KIF5B-RET were identified by RNA-Seq as well as a third novel fusion transcript that was formed between exons 1–9 of SND1 and exons 2 to 3′ end of BRAF. This in-frame fusion was observed in 3/89 tested tumors and 2/64 additional never smoker lung adenocarcinoma samples. Ectopic expression of SND1-BRAF in H1299 cells increased phosphorylation levels of MEK/ERK, cell proliferation, and spheroid formation compared to parental mock-transfected control. Jointly, our results suggest a potential role of the novel BRAF fusion in lung cancer development and therapy.
doi:10.1038/srep09755
PMCID: PMC4434945  PMID: 25985019
5.  Genome-wide association study identifies multiple susceptibility loci for diffuse large B-cell lymphoma 
Cerhan, James R | Berndt, Sonja I | Vijai, Joseph | Ghesquières, Hervé | McKay, James | Wang, Sophia S | Wang, Zhaoming | Yeager, Meredith | Conde, Lucia | de Bakker, Paul I W | Nieters, Alexandra | Cox, David | Burdett, Laurie | Monnereau, Alain | Flowers, Christopher R | De Roos, Anneclaire J | Brooks-Wilson, Angela R | Lan, Qing | Severi, Gianluca | Melbye, Mads | Gu, Jian | Jackson, Rebecca D | Kane, Eleanor | Teras, Lauren R | Purdue, Mark P | Vajdic, Claire M | Spinelli, John J | Giles, Graham G | Albanes, Demetrius | Kelly, Rachel S | Zucca, Mariagrazia | Bertrand, Kimberly A | Zeleniuch-Jacquotte, Anne | Lawrence, Charles | Hutchinson, Amy | Zhi, Degui | Habermann, Thomas M | Link, Brian K | Novak, Anne J | Dogan, Ahmet | Asmann, Yan W | Liebow, Mark | Thompson, Carrie A | Ansell, Stephen M | Witzig, Thomas E | Weiner, George J | Veron, Amelie S | Zelenika, Diana | Tilly, Hervé | Haioun, Corinne | Molina, Thierry Jo | Hjalgrim, Henrik | Glimelius, Bengt | Adami, Hans-Olov | Bracci, Paige M | Riby, Jacques | Smith, Martyn T | Holly, Elizabeth A | Cozen, Wendy | Hartge, Patricia | Morton, Lindsay M | Severson, Richard K | Tinker, Lesley F | North, Kari E | Becker, Nikolaus | Benavente, Yolanda | Boffetta, Paolo | Brennan, Paul | Foretova, Lenka | Maynadie, Marc | Staines, Anthony | Lightfoot, Tracy | Crouch, Simon | Smith, Alex | Roman, Eve | Diver, W Ryan | Offit, Kenneth | Zelenetz, Andrew | Klein, Robert J | Villano, Danylo J | Zheng, Tongzhang | Zhang, Yawei | Holford, Theodore R | Kricker, Anne | Turner, Jenny | Southey, Melissa C | Clavel, Jacqueline | Virtamo, Jarmo | Weinstein, Stephanie | Riboli, Elio | Vineis, Paolo | Kaaks, Rudolph | Trichopoulos, Dimitrios | Vermeulen, Roel C H | Boeing, Heiner | Tjonneland, Anne | Angelucci, Emanuele | Di Lollo, Simonetta | Rais, Marco | Birmann, Brenda M | Laden, Francine | Giovannucci, Edward | Kraft, Peter | Huang, Jinyan | Ma, Baoshan | Ye, Yuanqing | Chiu, Brian C H | Sampson, Joshua | Liang, Liming | Park, Ju-Hyun | Chung, Charles C | Weisenburger, Dennis D | Chatterjee, Nilanjan | Fraumeni, Joseph F | Slager, Susan L | Wu, Xifeng | de Sanjose, Silvia | Smedby, Karin E | Salles, Gilles | Skibola, Christine F | Rothman, Nathaniel | Chanock, Stephen J
Nature genetics  2014;46(11):1233-1238.
doi:10.1038/ng.3105
PMCID: PMC4213349  PMID: 25261932
6.  TP53 mutations, tetraploidy and homologous recombination repair defects in early stage high-grade serous ovarian cancer 
Nucleic Acids Research  2015;43(14):6945-6958.
To determine early somatic changes in high-grade serous ovarian cancer (HGSOC), we performed whole genome sequencing on a rare collection of 16 low stage HGSOCs. The majority showed extensive structural alterations (one had an ultramutated profile), exhibited high levels of p53 immunoreactivity, and harboured a TP53 mutation, deletion or inactivation. BRCA1 and BRCA2 mutations were observed in two tumors, with nine showing evidence of a homologous recombination (HR) defect. Combined Analysis with The Cancer Genome Atlas (TCGA) indicated that low and late stage HGSOCs have similar mutation and copy number profiles. We also found evidence that deleterious TP53 mutations are the earliest events, followed by deletions or loss of heterozygosity (LOH) of chromosomes carrying TP53, BRCA1 or BRCA2. Inactivation of HR appears to be an early event, as 62.5% of tumours showed a LOH pattern suggestive of HR defects. Three tumours with the highest ploidy had little genome-wide LOH, yet one of these had a homozygous somatic frame-shift BRCA2 mutation, suggesting that some carcinomas begin as tetraploid then descend into diploidy accompanied by genome-wide LOH. Lastly, we found evidence that structural variants (SV) cluster in HGSOC, but are absent in one ultramutated tumor, providing insights into the pathogenesis of low stage HGSOC.
doi:10.1093/nar/gkv111
PMCID: PMC4538798  PMID: 25916844
7.  Expression of Polarity Genes in Human Cancer 
Cancer Informatics  2015;14(Suppl 3):15-28.
Polarity protein complexes are crucial for epithelial apical–basal polarity and directed cell migration. Since alterations of these processes are common in cancer, polarity proteins have been proposed to function as tumor suppressors or oncogenic promoters. Here, we review the current understanding of polarity protein functions in epithelial homeostasis, as well as tumor formation and progression. As most previous studies focused on the function of single polarity proteins in simplified model systems, we used a genomics approach to systematically examine and identify the expression profiles of polarity genes in human cancer. The expression profiles of polarity genes were distinct in different human tissues and classified cancer types. Additionally, polarity expression profiles correlated with disease progression and aggressiveness, as well as with identified cancer types, where specific polarity genes were commonly altered. In the case of Scribble, gene expression analysis indicated its common amplification and upregulation in human cancer, suggesting a tumor promoting function.
doi:10.4137/CIN.S18964
PMCID: PMC4390136  PMID: 25991909
polarity proteins; cancer genomics; breast cancer; glioblastoma multiforme
8.  Chronically endurance‐trained individuals preserve skeletal muscle mitochondrial gene expression with age but differences within age groups remain 
Physiological Reports  2014;2(12):e12239.
Abstract
Maintenance of musculoskeletal function in older adults is critically important for preserving cardiorespiratory function and health span. Aerobic endurance training (ET) improves skeletal muscle metabolic function including age‐related declines in muscle mitochondrial function. To further understand the underlying mechanism of enhanced muscle function with ET, we profiled the gene transcription (mRNA levels) patterns by gene array and determined the canonical pathways associated with skeletal muscle aging in a cross‐sectional study involving vastus lateralis muscle biopsy samples of four subgroups (young and old, trained, and untrained). We first analyzed the sedentary individuals and then sought to identify the pathways impacted by long‐term ET (>4 years) and determined the age effect. We found that skeletal muscle aging in older sedentary adults decreased mitochondrial genes and pathways involved in oxidative phosphorylation while elevating pathways in redox homeostasis. In older adults compared to their younger counterparts who chronically perform ET however, those differences were absent. ET did, however, impact nearly twice as many genes in younger compared to older participants including downregulation of gene transcripts involved in protein ubiquitination and the ERK/MAPK pathways. This study demonstrates that in individuals who are chronically endurance trained, the transcriptional profile is normalized for mitochondrial genes but aging impacts the number of genes that respond to ET including many involved in protein homeostasis and cellular stress.
e12239
Transcriptional patterns in skeletal muscle are distinct in older compared to young adults. Although chronic endurance training in older adults restores the majority of the mitochondria transcripts to expression levels similar to young, there are many genes involved in protein homeostasis and cellular stress that exhibit attenuated responses to exercise in old compared to young adults.
doi:10.14814/phy2.12239
PMCID: PMC4332217  PMID: 25524277
Aging; exercise; mitochondria; oxidative damage; proteasome; sarcopenia
9.  CXCR5 polymorphisms in non-Hodgkin lymphoma risk and prognosis 
CXCR5 [chemokine (C-X-C motif) receptor 5; also known as Burkitt lymphoma receptor 1 (BCR1)] is expressed on mature B-cells, subsets of CD4+ and CD8+ T-cells, and skin-derived migratory dendritic cells. Together with its ligand, CXCL13, CXCR5 is involved in guiding B-cells into the B-cell zones of secondary lymphoid organs as well as T-cell migration. This study evaluated the role of common germline genetic variation in CXCR5 in the risk and prognosis of non-Hodgkin lymphoma (NHL) using a clinic-based study of 1521 controls and 2694 NHL cases including 710 chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL), 586 diffuse large B-cell lymphoma (DLBCL), 588 follicular lymphoma (FL), 137 mantle cell lymphoma (MCL), 230 marginal zone lymphoma (MZL) and 158 peripheral T-cell lymphoma (PTCL). Of the ten CXCR5 tag SNPs in our study, five were associated with risk of NHL, with rs1790192 having the strongest association (OR=1.19, 95%CI 1.08–1.30; p=0.0003). This SNP was most strongly associated with the risk of FL (OR=1.44, 95%CI 1.25–1.66; p=3.1×10−7), with a lower degree of association with DLBCL (OR=1.16, 95%CI 1.01–1.33; p=0.04) and PTCL (OR=1.29, 95%CI 1.02–1.64; p=0.04) but no association with the risk of MCL or MZL. For FL patients that were observed as initial disease management, the number of minor alleles of rs1790192 was associated with better event-free survival (EFS) (HR=0.64; 95%CI 0.47–0.87; p=0.004). These results provide additional evidence for a role of host genetic variation in CXCR5 in lymphomagenesis, particularly for FL.
doi:10.1007/s00262-013-1452-4
PMCID: PMC3758443  PMID: 23812490
non-Hodgkin lymphoma; SNPs; prognosis; prospective cohort; case-control
10.  Clinical Correlates of Autosomal Chromosomal Abnormalities in an Electronic Medical Record–Linked Genome-Wide Association Study: A Case Series 
Although mosaic autosomal chromosomal abnormalities are being increasingly detected as part of high-density genotyping studies, the clinical correlates are unclear. From an electronic medical record (EMR)–based genome-wide association study (GWAS) of peripheral arterial disease, log-R-ratio and B-allele-frequency data were used to identify mosaic autosomal chromosomal abnormalities including copy number variation and loss of heterozygosity. The EMRs of patients with chromosomal abnormalities and those without chromosomal abnormalities were reviewed to compare clinical characteristics. Among 3336 study participants, 0.75% (n = 25, mean age = 74.8 ± 10.7 years, 64% men) had abnormal intensity plots indicative of autosomal chromosomal abnormalities. A hematologic malignancy was present in 8 patients (32%), of whom 4 also had a solid organ malignancy while 2 patients had a solid organ malignancy only. In 50 age- and sex-matched participants without chromosomal abnormalities, there was a lower rate of hematologic malignancies (2% vs 32%, P < .001) but not solid organ malignancies (20% vs 24%, P = .69). We also report the clinical characteristics of each patient with the observed chromosomal abnormalities. Interestingly, among 5 patients with 20q deletions, 4 had a myeloproliferative disorder while all 3 men in this group had prostate cancer. In summary, in a GWAS of 3336 adults, 0.75% had autosomal chromosomal abnormalities and nearly a third of them had hematologic malignancies. A potential novel association between 20q deletions, myeloproliferative disorders, and prostate cancer was also noted.
PMCID: PMC4130164  PMID: 25125939
copy number variation; genome-wide association studies; loss of heterozygosity; mosaic abnormalities; mosaic deletion; myeloproliferative disorders; prostate cancer; unipaternal disomy
11.  Identification of Novel Variants in Colorectal Cancer Families by High-Throughput Exome Sequencing 
Background
Colorectal cancer (CRC) in densely affected families without Lynch Syndrome may be due to mutations in undiscovered genetic loci. Familial linkage analyses have yielded disparate results; the use of exome sequencing in coding regions may identify novel segregating variants.
Methods
We completed exome sequencing on 40 affected cases from 16 multi-case pedigrees to identify novel loci. Variants shared among all sequenced cases within each family were identified and filtered to exclude common variants and single nucleotide variants (SNVs) predicted to be benign.
Results
We identified 32 nonsense or splice-site SNVs, 375 missense SNVs, 1,394 synonymous or non-coding SNVs, and 50 indels in the 16 families. Of particular interest are two validated and replicated missense variants in CENPE and KIF23, which are both located within previously reported CRC linkage regions, on chromosomes 1 and 15, respectively.
Conclusions
Whole-exome sequencing identified DNA variants in multiple genes. Additional sequencing of these genes in additional samples will further elucidate the role of variants in these regions in colorectal cancer susceptibility.
Impact
Exome sequencing of familial CRC cases can identify novel rare variants that may influence disease risk.
doi:10.1158/1055-9965.EPI-12-1226
PMCID: PMC3704223  PMID: 23637064
colorectal cancer; familial and hereditary cancers; exome sequencing; rare variants; family study design
12.  A Phase I Trial of Immunostimulatory CpG 7909 Oligodeoxynucleotide and 90Yttrium Ibritumomab Tiuxetan Radioimmunotherapy for Relapsed B-cell Non-Hodgkin Lymphoma 
American journal of hematology  2013;88(7):589-593.
Radioimmunotherapy (RIT) for relapsed indolent non-Hodgkin lymphoma produces overall response rates (ORR) of 80% with mostly partial remissions. Synthetic CpG oligonucleotides change the phenotype of malignant B-cells, are immunostimulatory, and can produce responses when injected intratumorally and combined with conventional radiation. In this phase I trial we tested systemic administration of both CpG and RIT. Eligible patients had biopsy-proven previously treated CD20+ B-cell NHL and met criteria for RIT. Patients received rituximab 250 mg/m2 days 1,8, and 15; 111In-ibritumomab tiuxetan days 1, 8; CpG 7909 days 6, 13, 20, 27; and 0.4 mCi/kg of 90Y-ibritumomab tiuxetan day 15. The doses of CpG 7909 tested were 0.08, 0.16, 0.32 (six patients each) and 0.48 mg/kg (12 patients) IV over 2 hours without dose limiting toxicity. The ORR was 93% (28/30) with 63% (19/30) complete remission (CR); median progression free survival of 42.7 months (95% CI 18-NR); and median duration of response (DR) of 35 months (4.6-76+). Correlative studies demonstrated a decrease in IL10 and TNFα, and an increase in IL1β, in response to therapy. CpG 7909 at a dose of 0.48 mg/kg is safe with standard RIT and produces a high CR rate and long DR; these results warrant confirmation.
doi:10.1002/ajh.23460
PMCID: PMC3951424  PMID: 23619698
lymphoma; radioimmunotherapy; rituximab; ibritumomab tiuxetan; CpG 7909
13.  MAP-RSeq: Mayo Analysis Pipeline for RNA sequencing 
BMC Bioinformatics  2014;15:224.
Background
Although the costs of next generation sequencing technology have decreased over the past years, there is still a lack of simple-to-use applications, for a comprehensive analysis of RNA sequencing data. There is no one-stop shop for transcriptomic genomics. We have developed MAP-RSeq, a comprehensive computational workflow that can be used for obtaining genomic features from transcriptomic sequencing data, for any genome.
Results
For optimization of tools and parameters, MAP-RSeq was validated using both simulated and real datasets. MAP-RSeq workflow consists of six major modules such as alignment of reads, quality assessment of reads, gene expression assessment and exon read counting, identification of expressed single nucleotide variants (SNVs), detection of fusion transcripts, summarization of transcriptomics data and final report. This workflow is available for Human transcriptome analysis and can be easily adapted and used for other genomes. Several clinical and research projects at the Mayo Clinic have applied the MAP-RSeq workflow for RNA-Seq studies. The results from MAP-RSeq have thus far enabled clinicians and researchers to understand the transcriptomic landscape of diseases for better diagnosis and treatment of patients.
Conclusions
Our software provides gene counts, exon counts, fusion candidates, expressed single nucleotide variants, mapping statistics, visualizations, and a detailed research data report for RNA-Seq. The workflow can be executed on a standalone virtual machine or on a parallel Sun Grid Engine cluster. The software can be downloaded from http://bioinformaticstools.mayo.edu/research/maprseq/.
doi:10.1186/1471-2105-15-224
PMCID: PMC4228501  PMID: 24972667
Transcriptomic sequencing; RNA-Seq; Bioinformatics workflow; Gene expression; Exon counts; Fusion transcripts; Expressed single nucleotide variants; RNA-Seq reports
14.  PatternCNV: a versatile tool for detecting copy number changes from exome sequencing data 
Bioinformatics  2014;30(18):2678-2680.
Motivation: Exome sequencing (exome-seq) data, which are typically used for calling exonic mutations, have also been utilized in detecting DNA copy number variations (CNVs). Despite the existence of several CNV detection tools, there is still a great need for a sensitive and an accurate CNV-calling algorithm with built-in QC steps, and does not require a paired reference for each sample.
Results: We developed a novel method named PatternCNV, which (i) accounts for the read coverage variations between exons while leveraging the consistencies of this variability across different samples; (ii) reduces alignment BAM files to WIG format and therefore greatly accelerates computation; (iii) incorporates multiple QC measures designed to identify outlier samples and batch effects; and (iv) provides a variety of visualization options including chromosome, gene and exon-level views of CNVs, along with a tabular summarization of the exon-level CNVs. Compared with other CNV-calling algorithms using data from a lymphoma exome-seq study, PatternCNV has higher sensitivity and specificity.
Availability and implementation: The software for PatternCNV is implemented using Perl and R, and can be used in Mac or Linux environments. Software and user manual are available at http://bioinformaticstools.mayo.edu/research/patterncnv/, and R package at https://github.com/topsoil/patternCNV/.
Contact: Asmann.Yan@mayo.edu
Supplementary information: Supplementary data are available at Bioinformatics online.
doi:10.1093/bioinformatics/btu363
PMCID: PMC4155258  PMID: 24876377
15.  Mapping of the IRF8 gene identifies a 3’ UTR variant associated with risk of chronic lymphocytic leukemia but not other common non-Hodgkin lymphoma subtypes 
Background
Our genome-wide association study (GWAS) of chronic lymphocytic leukemia (CLL) identified 4 highly-correlated intronic variants within the IRF8 gene that were associated with CLL. These results were further supported by a recent meta-analysis of our GWAS with two other GWAS of CLL, supporting the IRF8 gene as a strong candidate for CLL risk.
Methods
To refine the genetic association of CLL risk, we performed Sanger sequencing of IRF8 in 94 CLL cases and 96 controls. We then performed fine-mapping by genotyping 39 variants (of which 10 were identified from sequencing) in 745 CLL cases and 1521 controls. We also assessed these associations with risk of other non-Hodgkin lymphoma (NHL) subtypes.
Results
The strongest association with CLL risk was observed with a common SNP located within the 3’ UTR of IRF8 (rs1044873, log additive odds ratio = 0.7, P=1.81×10−6). This SNP was not associated with the other NHL subtypes (all P>0.05).
Conclusions
We provide evidence that rs1044873 in the IRF8 gene accounts for the initial GWAS signal for CLL risk. This association appears to be unique to CLL with little support for association with other common NHL subtypes. Future work is needed to assess functional role of IRF8 in CLL etiology.
Impact
These data provide support that a functional variant within the 3’ UTR of IRF8 may be driving the GWAS signal seen on 16q24.1 for CLL risk.
doi:10.1158/1055-9965.EPI-12-1217
PMCID: PMC3596428  PMID: 23307532
CLL; NHL; SNPs; IRF8; risk locus
16.  Chronic Caloric Restriction Preserves Mitochondrial Function in Senescence Without Increasing Mitochondrial Biogenesis 
Cell metabolism  2012;16(6):777-788.
SUMMARY
Caloric restriction (CR) mitigates many detrimental effects of aging and prolongs lifespan. CR has been suggested to increase mitochondrial biogenesis, thereby attenuating age-related declines in mitochondrial function; a concept that is challenged by recent studies. Here we show that lifelong CR in mice prevents age-related loss of mitochondrial oxidative capacity and efficiency, measured in isolated mitochondria and permeabilized muscle fibers. We find that these beneficial effects of CR occur without increasing mitochondrial abundance. Whole-genome expression profiling and large-scale proteomic surveys revealed expression patterns inconsistent with increased mitochondrial biogenesis, which is further supported by lower mitochondrial protein synthesis with CR. We find that CR decreases oxidant emission, increases antioxidant scavenging, and minimizes oxidative damage to DNA and protein. These results demonstrate that CR preserves mitochondrial function by protecting the integrity and function of existing cellular components rather than by increasing mitochondrial biogenesis.
doi:10.1016/j.cmet.2012.11.003
PMCID: PMC3544078  PMID: 23217257
Caloric Restriction; Calorie restriction; dietary restriction; aging; mitochondria; protein synthesis; skeletal muscle; mitochondrial biogenesis
17.  Gene Expression, Single Nucleotide Variant and Fusion Transcript Discovery in Archival Material from Breast Tumors 
PLoS ONE  2013;8(11):e81925.
Advantages of RNA-Seq over array based platforms are quantitative gene expression and discovery of expressed single nucleotide variants (eSNVs) and fusion transcripts from a single platform, but the sensitivity for each of these characteristics is unknown. We measured gene expression in a set of manually degraded RNAs, nine pairs of matched fresh-frozen, and FFPE RNA isolated from breast tumor with the hybridization based, NanoString nCounter (226 gene panel) and with whole transcriptome RNA-Seq using RiboZeroGold ScriptSeq V2 library preparation kits. We performed correlation analyses of gene expression between samples and across platforms. We then specifically assessed whole transcriptome expression of lincRNA and discovery of eSNVs and fusion transcripts in the FFPE RNA-Seq data. For gene expression in the manually degraded samples, we observed Pearson correlations of >0.94 and >0.80 with NanoString and ScriptSeq protocols, respectively. Gene expression data for matched fresh-frozen and FFPE samples yielded mean Pearson correlations of 0.874 and 0.783 for NanoString (226 genes) and ScriptSeq whole transcriptome protocols respectively, p<2x10-16. Specifically for lincRNAs, we observed superb Pearson correlation (0.988) between matched fresh-frozen and FFPE pairs. FFPE samples across NanoString and RNA-Seq platforms gave a mean Pearson correlation of 0.838. In FFPE libraries, we detected 53.4% of high confidence SNVs and 24% of high confidence fusion transcripts. Sensitivity of fusion transcript detection was not overcome by an increase in depth of sequencing up to 3-fold (increase from ~56 to ~159 million reads). Both NanoString and ScriptSeq RNA-Seq technologies yield reliable gene expression data for degraded and FFPE material. The high degree of correlation between NanoString and RNA-Seq platforms suggests discovery based whole transcriptome studies from FFPE material will produce reliable expression data. The RiboZeroGold ScriptSeq protocol performed particularly well for lincRNA expression from FFPE libraries, but detection of eSNV and fusion transcripts was less sensitive.
doi:10.1371/journal.pone.0081925
PMCID: PMC3838386  PMID: 24278466
18.  An Integrated Model of the Transcriptome of HER2-Positive Breast Cancer 
PLoS ONE  2013;8(11):e79298.
Our goal in these analyses was to use genomic features from a test set of primary breast tumors to build an integrated transcriptome landscape model that makes relevant hypothetical predictions about the biological and/or clinical behavior of HER2-positive breast cancer. We interrogated RNA-Seq data from benign breast lesions, ER+, triple negative, and HER2-positive tumors to identify 685 differentially expressed genes, 102 alternatively spliced genes, and 303 genes that expressed single nucleotide sequence variants (eSNVs) that were associated with the HER2-positive tumors in our survey panel. These features were integrated into a transcriptome landscape model that identified 12 highly interconnected genomic modules, each of which represents a cellular processes pathway that appears to define the genomic architecture of the HER2-positive tumors in our test set. The generality of the model was confirmed by the observation that several key pathways were enriched in HER2-positive TCGA breast tumors. The ability of this model to make relevant predictions about the biology of breast cancer cells was established by the observation that integrin signaling was linked to lapatinib sensitivity in vitro and strongly associated with risk of relapse in the NCCTG N9831 adjuvant trastuzumab clinical trial dataset. Additional modules from the HER2 transcriptome model, including ubiquitin-mediated proteolysis, TGF-beta signaling, RHO-family GTPase signaling, and M-phase progression, were linked to response to lapatinib and paclitaxel in vitro and/or risk of relapse in the N9831 dataset. These data indicate that an integrated transcriptome landscape model derived from a test set of HER2-positive breast tumors has potential for predicting outcome and for identifying novel potential therapeutic strategies for this breast cancer subtype.
doi:10.1371/journal.pone.0079298
PMCID: PMC3815156  PMID: 24223926
19.  A Two-Stage Evaluation of Genetic Variation in Immune and Inflammation Genes with Risk of Non-Hodgkin Lymphoma Identifies New Susceptibility Locus in 6p21.3 Region 
Background
Non-Hodgkin lymphoma (NHL) is a malignancy of lymphocytes, and there is growing evidence for a role of germline genetic variation in immune genes in NHL etiology.
Methods
To identify susceptibility immune genes, we conducted a 2-stage analysis of single nucleotide polymorphisms (SNPs) from 1,253 genes using the Immune and Inflammation Panel. In Stage 1, we genotyped 7,670 SNPs in 425 NHL cases and 465 controls, and in Stage 2 we genotyped the top 768 SNPs on an additional 584 cases and 768 controls. The association of individual SNPs with NHL risk from a log-additive model was assessed using the Odds Ratios (ORs) and 95% confidence intervals (CI).
Results
In the pooled analysis, only the TAP2 coding SNP rs241447 (MAF=0.26; Thr655Ala) at 6p21.3 (OR=1.34, 95%CI 1.17-1.53) achieved statistical significance after accounting for multiple testing (p=3.1 × 10−5). The TAP2 SNP was strongly associated with follicular lymphoma (FL, OR=1.82, 95%CI 1.46-2.26; p=6.9 × 10−8), and was independent of other known loci (rs10484561 and rs2647012) from this region. The TAP2 SNP was also associated with diffuse large B-cell lymphoma (DLBCL, OR=1.38, 95% CI 1.08-1.77; p=0.011), but not chronic lymphocytic leukemia (OR=1.08; 95% CI 0.88-1.32). Higher TAP2 expression was associated with the risk allele in both FL and DLBCL tumors.
Conclusion
Genetic variation in TAP2 was associated with NHL risk overall, and FL risk in particular, and this was independent of other established loci from 6p21.3.
Impact
Genetic variation in antigen presentation of HLA class I molecules may play a role in lymphomagenesis.
doi:10.1158/1055-9965.EPI-12-0696
PMCID: PMC3467356  PMID: 22911334
genetics; non-Hodgkin lymphoma; immune function; single nucleotide polymorphisms
20.  Clinical Correlates of Autosomal Chromosomal Abnormalities in an Electronic Medical Record–Linked Genome-Wide Association Study 
Although mosaic autosomal chromosomal abnormalities are being increasingly detected as part of high-density genotyping studies, the clinical correlates are unclear. From an electronic medical record (EMR)–based genome-wide association study (GWAS) of peripheral arterial disease, log-R-ratio and B-allele-frequency data were used to identify mosaic autosomal chromosomal abnormalities including copy number variation and loss of heterozygosity. The EMRs of patients with chromosomal abnormalities and those without chromosomal abnormalities were reviewed to compare clinical characteristics. Among 3336 study participants, 0.75% (n = 25, mean age = 74.8 ± 10.7 years, 64% men) had abnormal intensity plots indicative of autosomal chromosomal abnormalities. A hematologic malignancy was present in 8 patients (32%), of whom 4 also had a solid organ malignancy while 2 patients had a solid organ malignancy only. In 50 age- and sex-matched participants without chromosomal abnormalities, there was a lower rate of hematologic malignancies (2% vs 32%, P < .001) but not solid organ malignancies (20% vs 24%, P = .69). We also report the clinical characteristics of each patient with the observed chromosomal abnormalities. Interestingly, among 5 patients with 20q deletions, 4 had a myeloproliferative disorder while all 3 men in this group had prostate cancer. In summary, in a GWAS of 3336 adults, 0.75% had autosomal chromosomal abnormalities and nearly a third of them had hematologic malignancies. A potential novel association between 20q deletions, myeloproliferative disorders, and prostate cancer was also noted.
doi:10.1177/2324709613508932
PMCID: PMC4528839  PMID: 26425586
copy number variation; genome-wide association studies; loss of heterozygosity; mosaic abnormalities; mosaic deletion; myeloproliferative disorders; prostate cancer; unipaternal disomy
21.  Impact of Library Preparation on Downstream Analysis and Interpretation of RNA-Seq Data: Comparison between Illumina PolyA and NuGEN Ovation Protocol 
PLoS ONE  2013;8(8):e71745.
Objectives
The sequencing by the PolyA selection is the most common approach for library preparation. With limited amount or degraded RNA, alternative protocols such as the NuGEN have been developed. However, it is not yet clear how the different library preparations affect the downstream analyses of the broad applications of RNA sequencing.
Methods and Materials
Eight human mammary epithelial cell (HMEC) lines with high quality RNA were sequenced by Illumina’s mRNA-Seq PolyA selection and NuGEN ENCORE library preparation. The following analyses and comparisons were conducted: 1) the numbers of genes captured by each protocol; 2) the impact of protocols on differentially expressed gene detection between biological replicates; 3) expressed single nucleotide variant (SNV) detection; 4) non-coding RNAs, particularly lincRNA detection; and 5) intragenic gene expression.
Results
Sequences from the NuGEN protocol had lower (75%) alignment rate than the PolyA (over 90%). The NuGEN protocol detected fewer genes (12–20% less) with a significant portion of reads mapped to non-coding regions. A large number of genes were differentially detected between the two protocols. About 17–20% of the differentially expressed genes between biological replicates were commonly detected between the two protocols. Significantly higher numbers of SNVs (5–6 times) were detected in the NuGEN samples, which were largely from intragenic and intergenic regions. The NuGEN captured fewer exons (25% less) and had higher base level coverage variance. While 6.3% of reads were mapped to intragenic regions in the PolyA samples, the percentages were much higher (20–25%) for the NuGEN samples. The NuGEN protocol did not detect more known non-coding RNAs such as lincRNAs, but targeted small and “novel” lincRNAs.
Conclusion
Different library preparations can have significant impacts on downstream analysis and interpretation of RNA-seq data. The NuGEN provides an alternative for limited or degraded RNA but it has limitations for some RNA-seq applications.
doi:10.1371/journal.pone.0071745
PMCID: PMC3747248  PMID: 23977132
22.  A genome-wide association study of venous thromboembolism identifies risk variants in chromosomes 1q24.2 and 9q 
Summary
Objectives
To identify venous thromboembolism (VTE) disease-susceptibility genes.
Patients/Methods
We performed in silico genome wide association (GWAS) analyses using genotype data imputed to ~2.5 million single nucleotide polymorphisms (SNPs) from adults with objectively-diagnosed VTE (n=1503), and controls frequency-matched on age and sex (n=1459; discovery population). SNPs exceeding genome-wide significance were replicated in a separate population (VTE cases, n=1407; controls, n=1418). Genes associated with VTE were resequenced.
Results
Seven SNPs exceeded genome-wide significance (P < 5 × 10-8); four on chromosome 1q24.2 (F5 rs6025 [Factor V Leiden], BLZF1 rs7538157, NME7 rs16861990 and SLC19A2 rs2038024) and three on chromosome 9q34.2 (ABO rs2519093 [ABO intron 1], rs495828, rs8176719 [ABO blood type O allele]). The replication study confirmed a significant association of F5, NME7, and ABO with VTE. However, F5 was the main signal on 1q24.2 as only ABO SNPs remained significantly associated with VTE after adjusting for F5 rs6025. This 1q24.2 region was shown to be inherited as a haplotype block. ABO resequencing identified 15 novel single nucleotide variations (SNV) in ABO intron 6 and the ABO 3’ UTR that were strongly associated with VTE (P < 10-4) and belonged to three distinct linkage disequilibrium (LD) blocks; none were in LD with ABO rs8176719 or rs2519093. Our sample size provided 80% power to detect odds ratios=2.0 and 1.51 for minor allele frequencies=0.05 and 0.5, respectively (α=1 × 10-8; 1% VTE prevalence).
Conclusions
Aside from F5 rs6025, ABO rs8176719 and rs2519093, and F2 rs1799963, additional common and high VTE-risk SNPs among whites are unlikely.
doi:10.1111/j.1538-7836.2012.04810.x
PMCID: PMC3419811  PMID: 22672568
venous thromboembolism; deep vein thrombosis; pulmonary embolism; genetics; genome-wide scan; epidemiology
23.  Early life sun exposure, vitamin D-related gene variants, and risk of non-Hodgkin lymphoma 
Cancer causes & control : CCC  2012;23(7):1017-1029.
Purpose
It has been hypothesized that vitamin D mediates the inverse relationship between sun exposure and non-Hodgkin lymphoma (NHL) risk reported in several recent studies. We evaluated the association of self-reported sun exposure at ages <13, 13–21, 22–40, and 41+ years and 19 single nucleotide polymorphisms (SNPs) from 4 candidate genes relevant to vitamin D metabolism (RXR, VDR, CYP24A1, CYP27B1) with NHL risk.
Methods
This analysis included 1,009 newly diagnosed NHL cases and 1,233 frequency-matched controls from an ongoing clinic-based study. Odds ratios (OR), 95 % confidence intervals (CI), and tests for trend were estimated using unconditional logistic regression.
Results
There was a significant decrease in NHL risk with increased sun exposure at ages 13–21 years (OR≥15 vs. ≤3 h/week = 0.68; 95 % CI, 0.43–1.08; ptrend = 0.0025), which attenuated for older ages at exposure. We observed significant main effect associations for 3 SNPs in VDR and 1 SNP in CYP24A1: rs886441 (ORper-allele = 0.82; 95 % CI, 0.70–0.96; p = 0.016), rs3819545 (ORper-allele = 1.24; 95 % CI, 1.10–1.40; p = 0.00043), and rs2239186 (ORper-allele = 1.22; 95 % CI, 1.05–1.41; p = 0.0095) for VDR and rs2762939 (ORper-allele = 0.85; 95 % CI, 0.75–0.98; p = 0.023) for CYP24A1. Moreover, the effect of sun exposure at age 13–21 years on overall NHL risk appears to be modified by germline variation in VDR (rs4516035; pinteraction = 0.0066). Exploratory analysis indicated potential heterogeneity of these associations by NHL subtype.
Conclusion
These results suggest that germline genetic variation in VDR, and therefore the vitamin D pathway, may mediate an association between early life sun exposure and NHL risk.
doi:10.1007/s10552-012-9967-0
PMCID: PMC3589750  PMID: 22544453
Ultraviolet radiation; Vitamin D; VDR; Molecular epidemiology; Non-Hodgkin lymphoma
24.  Concordance of Changes in Metabolic Pathways Based on Plasma Metabolomics and Skeletal Muscle Transcriptomics in Type 1 Diabetes 
Diabetes  2012;61(5):1004-1016.
Insulin regulates many cellular processes, but the full impact of insulin deficiency on cellular functions remains to be defined. Applying a mass spectrometry–based nontargeted metabolomics approach, we report here alterations of 330 plasma metabolites representing 33 metabolic pathways during an 8-h insulin deprivation in type 1 diabetic individuals. These pathways included those known to be affected by insulin such as glucose, amino acid and lipid metabolism, Krebs cycle, and immune responses and those hitherto unknown to be altered including prostaglandin, arachidonic acid, leukotrienes, neurotransmitters, nucleotides, and anti-inflammatory responses. A significant concordance of metabolome and skeletal muscle transcriptome–based pathways supports an assumption that plasma metabolites are chemical fingerprints of cellular events. Although insulin treatment normalized plasma glucose and many other metabolites, there were 71 metabolites and 24 pathways that differed between nondiabetes and insulin-treated type 1 diabetes. Confirmation of many known pathways altered by insulin using a single blood test offers confidence in the current approach. Future research needs to be focused on newly discovered pathways affected by insulin deficiency and systemic insulin treatment to determine whether they contribute to the high morbidity and mortality in T1D despite insulin treatment.
doi:10.2337/db11-0874
PMCID: PMC3331761  PMID: 22415876
25.  SAAP-RRBS: streamlined analysis and annotation pipeline for reduced representation bisulfite sequencing 
Bioinformatics  2012;28(16):2180-2181.
Summary: Reduced representation bisulfite sequencing (RRBS) is a cost-effective approach for genome-wide methylation pattern profiling. Analyzing RRBS sequencing data is challenging and specialized alignment/mapping programs are needed. Although such programs have been developed, a comprehensive solution that provides researchers with good quality and analyzable data is still lacking. To address this need, we have developed a Streamlined Analysis and Annotation Pipeline for RRBS data (SAAP-RRBS) that integrates read quality assessment/clean-up, alignment, methylation data extraction, annotation, reporting and visualization. This package facilitates a rapid transition from sequencing reads to a fully annotated CpG methylation report to biological interpretation.
Availability and implementation: SAAP-RRBS is freely available to non-commercial users at the web site http://ndc.mayo.edu/mayo/research/biostat/stand-alone-packages.cfm.
Contact: baheti.saurabh@mayo.edu or sun.zhifu@mayo.edu
Supplementary Information: Supplementary data are available at Bioinformatics online.
doi:10.1093/bioinformatics/bts337
PMCID: PMC3413387  PMID: 22689387

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