Eckloff, Bruce W.

Abstract The prevalence of germline pathogenic mutations in a comprehensive panel of cancer predisposition genes is not well-defined for patients with pancreatic ductal adenocarcinoma (PDAC). To estimate the frequency of mutations in a panel of 22 cancer predisposition genes, 96 patients unselected for a family history of cancer who were recruited to the Mayo Clinic Pancreatic Cancer patient registry over a 12-month period were screened by next-generation sequencing. Fourteen pathogenic mutations in 13 patients (13.5%) were identified in eight genes: four in ATM, two in BRCA2, CHEK2, and MSH6, and one in BARD1, BRCA1, FANCM, and NBN. These included nine mutations (9.4%) in established pancreatic cancer genes. Three mutations were found in patients with a first-degree relative with PDAC, and 10 mutations were found in patients with first- or second-degree relatives with breast, pancreas, colorectal, ovarian, or endometrial cancers. These results suggest that a substantial proportion of patients with PDAC carry germline mutations in predisposition genes associated with other cancers and that a better understanding of pancreatic cancer risk will depend on evaluation of families with broad constellations of tumors. These findings highlight the need for recommendations governing germline gene-panel testing of patients with pancreatic cancer. Cancer Epidemiol Biomarkers Prev; 25(1); 207–11. ©2015 AACR.

ABSTRACT We report on nine draft genomes of Pseudomonas aeruginosa isolates, assembled using a hybrid paired-end and Nextera mate-pair library approach. Eight are of clinical origin, and one is the ATCC 27853 strain. We also report their multilocus sequence types.

Background— The molecular underpinnings of hypoplastic left heart are poorly understood. Staged surgical palliation has dramatically improved survival, yet eventual failure of the systemic right ventricle necessitates cardiac transplantation in a subset of patients. We sought to identify genetic determinants of hypoplastic left heart with latent right ventricular dysfunction in individuals with a Fontan circulation. Methods and Results— Evaluation of cardiac structure and function by echocardiography in patients with hypoplastic left heart and their first-degree relatives identified 5 individuals with right ventricular ejection fraction ≤40% after Fontan operation. Whole genome sequencing was performed on DNA from 21 family members, filtering for genetic variants with allele frequency <1% predicted to alter protein structure or expression. Secondary family-based filtering for de novo and recessive variants revealed rare inherited missense mutations on both paternal and maternal alleles of MYH6 , encoding myosin heavy chain 6, in 2 patients who developed right ventricular dysfunction 3 to 11 years postoperatively. Parents and siblings who were heterozygous carriers had normal echocardiograms. Protein modeling of the 4 highly conserved amino acid substitutions, residing in both head and tail domains, predicted perturbation of protein structure and function. Conclusions— In contrast to dominant MYH6 mutations with variable penetrance identified in other congenital heart defects and dilated cardiomyopathy, this study reveals compound heterozygosity for recessive MYH6 mutations in patients with hypoplastic left heart and reduced systemic right ventricular ejection fraction. These findings implicate a shared molecular basis for the developmental arrest and latent myopathy of left and right ventricles, respectively.

Abstract Purpose: Primary central nervous system lymphoma (PCNSL) is an aggressive non-Hodgkin lymphoma confined to the central nervous system. Whether there is a PCNSL-specific genomic signature and, if so, how it differs from systemic diffuse large B-cell lymphoma (DLBCL) is uncertain. Experimental Design: We performed a comprehensive genomic study of tumor samples from 19 immunocompetent PCNSL patients. Testing comprised array-comparative genomic hybridization and whole exome sequencing. Results: Biallelic inactivation of TOX and PRKCD was recurrently found in PCNSL but not in systemic DLBCL, suggesting a specific role in PCNSL pathogenesis. In addition, we found a high prevalence of MYD88 mutations (79%) and CDKN2A biallelic loss (60%). Several genes recurrently affected in PCNSL were common with systemic DLBCL, including loss of TNFAIP3, PRDM1, GNA13, TMEM30A, TBL1XR1, B2M, CD58, activating mutations of CD79B, CARD11, and translocations IgH-BCL6. Overall, B-cell receptor/Toll-like receptor/NF-κB pathways were altered in &gt;90% of PNCSL, highlighting its value for targeted therapeutic approaches. Furthermore, integrated analysis showed enrichment of pathways associated with immune response, proliferation, apoptosis, and lymphocyte differentiation. Conclusions: In summary, genome-wide analysis uncovered novel recurrent alterations, including TOX and PRKCD, helping to differentiate PCNSL from systemic DLBCL and related lymphomas. Clin Cancer Res; 21(17); 3986–94. ©2015 AACR.

Abstract Background: Fusion genes, transcripts, and proteins are key drivers of hematopoietic oncogenesis and can serve as effective therapeutic targets. Among peripheral T-cell lymphomas (PTCLs), little is known about fusion genes except for those involving ALK. Discovery of fusion genes may provide therapeutic targets for PTCLs, which have poor outcomes with conventional therapy. We have developed methods for detecting candidate fusions using (1) mate-pair DNA sequencing (MPseq), an approach that spans the entire genome at a fraction of the cost of traditional whole-genome sequencing, and (2) RNA sequencing (RNAseq). Each technique has strengths, limitations, and false discovery rates. Here, we integrated results of both methods to discover and orthogonally validate expressed fusion genes in PTCLs. Methods: DNA and RNA were extracted from 49 frozen, OCT-embedded clinical PTCL specimens, including 25 anaplastic large cell lymphomas; 16 PTCLs, not otherwise specified; and 8 other PTCLs. MPseq and RNAseq were performed using Illumina library protocols and a HiSeq 2000. Detection of fusion genes and transcripts followed our published methods (Blood 2012;120:2280 and Nucleic Acids Res 2011;39:e100, respectively). Functional annotation of genes involved in fusions was performed using DAVID. Results: Of 2818 candidate chromosomal rearrangements identified by MPseq and 90 candidate fusion transcripts identified by RNAseq, 45 events were present in both datasets (mean/case, 0.9; range, 0-7). Fusions were inter-chromosomal in 16 and intra-chromosomal in 29. Annotation clusters with the highest enrichment scores related to SH2 domain-containing proteins and tyrosine kinases (including FER and MAP2K3). Seven genes were recurrently involved in fusions, including known fusion partners such as ALK and previously unreported fusion partners such as PPP1R8, a phosphatase inhibitor important for the activity of Polycomb group proteins such as EZH2. Detection of candidate events only by MPseq could be explained in part by breakpoints mapping to non-genic regions (79% of events). Detection only by RNAseq could be explained in part by unannotated transcripts spanning neighboring named genes (median intra-chromosomal distance, 0.09 MB vs. 12.7 MB for intra-chromosomal candidates identified by MPseq; p&lt;0.0001, Wilcoxon test). Conclusions: Integrated DNA/RNA sequencing is an effective, clinically feasible tool for simultaneous discovery and orthogonal validation of expressed fusion genes. This approach yielded fusions in PTCLs involving genes with key functions in lymphocytes, including novel and recurrent fusions, some of which might be targetable with compounds currently in clinical trial. Candidate intra-chromosomal fusion transcripts not identified by MPseq may represent unrecognized isoforms or the results of novel read-through mechanisms, and merit further study. Citation Format: Andrew L. Feldman, George Vasmatzis, Yan W. Asmann, Sarah H. Johnson, Bruce W. Eckloff, Sumit Middha, Jaime I. Davila, Paul J. Kurtin, Brian K. Link, Stephen M. Ansell, James R. Cerhan. Integrated DNA/RNA sequencing for discovery and orthogonal validation of expressed fusion genes in peripheral T-cell lymphomas. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5585. doi:10.1158/1538-7445.AM2014-5585

Background— Long-QT syndrome (LQTS) may result in syncope, seizures, or sudden cardiac arrest. Although 16 LQTS-susceptibility genes have been discovered, 20% to 25% of LQTS remains genetically elusive. Methods and Results— We performed whole-exome sequencing child–parent trio analysis followed by recessive and sporadic inheritance modeling and disease-network candidate analysis gene ranking to identify a novel underlying genetic mechanism for LQTS. Subsequent mutational analysis of the candidate gene was performed with polymerase chain reaction, denaturing high-performance liquid chromatography, and DNA sequencing on a cohort of 33 additional unrelated patients with genetically elusive LQTS. After whole-exome sequencing and variant filtration, a homozygous p.D18fs*13 TRDN -encoded triadin frameshift mutation was discovered in a 10-year-old female patient with LQTS with a QTc of 500 milliseconds who experienced recurrent exertion-induced syncope/cardiac arrest beginning at 1 year of age. Subsequent mutational analysis of TRDN revealed either homozygous or compound heterozygous frameshift mutations in 4 of 33 unrelated cases of LQTS (12%). All 5 TRDN-null patients displayed extensive T-wave inversions in precordial leads V 1 through V 4 , with either persistent or transient QT prolongation and severe disease expression of exercise-induced cardiac arrest in early childhood (≤3 years of age) and required aggressive therapy. The overall yield of TRDN mutations was significantly greater in patients ≤10 years of age (5 of 10, 50%) compared with older patients (0 of 24, 0%; P =0.0009). Conclusions— We identified TRDN as a novel underlying genetic basis for recessively inherited LQTS. All TRDN-null patients had strikingly similar phenotypes. Given the recurrent nature of potential lethal arrhythmias, patients fitting this phenotypic profile should undergo cardiac TRDN genetic testing.

Abstract Colorectal cancer (CRC) is estimated to be the third most common cancer in both men and women in the US in 2012, accounting for over 50,000 deaths. Familial CRC accounts for approximately 30% of all CRC, yet only 5% of familial CRCs can be attributed to mutations in known hereditary colon cancer (HCC) genes. Many families with a strong family history of CRC do not have mutations in known CRC genes. Finding the genes underpinning CRC in these families may improve screening for disease and allow the development of more targeted therapeutics. We completed targeted sequencing of over 2,000 genes and miRNAs in 1,500 cases of CRC from the Colon Cancer Family Registry (CCFR) in an effort to identify rare variants associated with CRC risk and to identify mutations in known CRC genes missed by conventional sequencing. Several categories of genes were included: 18 known HCC genes; 18 candidate HCC genes; 185 genes in previously reported CRC linkage peaks; 1,423 miRNAs; and 363 genes identified through whole exome sequencing of 40 affected cases in 16 families with hereditary CRC (n=2,007 total genes sequenced). Genomic DNA samples were indexed, then libraries were made using Agilent's SureSelect Targeted Enrichment kit. Samples were pooled (96 samples/pool), then each pool of samples was run on five lanes on an Illumina HiSeq2000 (average of 19.2 samples/lane). GenomeGPS, an in-house developed workflow, was used for read alignment, variant calling, and annotation. In early analyses of the first 161 cases, the mean number of mapped reads exceeded 20 million per sample and over 90% of the target region exceeded 40x coverage. A total of 26,484 SNPs were identified and passed quality filtering. Sequencing identified known mutations in MMR genes in positive control cases as well as mutations in HCC genes in previously untested cases. Analysis is currently on-going on the remaining samples and we will report results on the full set of 1500 cases at the meeting. Citation Format: Melissa S. DeRycke, Shanaka R. Gunawardena, Sumit Middha, Shannon K. McDonnell, Shaun M. Riska, Zachary C. Fogarty, Bruce W. Eckloff, Daniel J. Schaid, Ellen L. Goode, Stephen N. Thibodeau. Targeted sequencing to identify rare variants in colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2548. doi:10.1158/1538-7445.AM2013-2548

Abstract The FKBP5 gene encodes the FKBP51 immunophilin, a negative regulator of AKT. Variability in level of FKBP5 expression is a major factor contributing to variation in response to several classes of chemotherapeutic agents including gemcitabine, first line treatment for pancreatic cancer. Genetic variation of FKBP5 could influence its expression, function, and, ultimately, treatment response of pancreatic cancer. We set out to comprehensively study the role of genetic variation in FKBP5 identified by Next Generation DNA resequencing in response to gemcitabine treatment of pancreatic cancer by utilizing both tumor and germline DNA samples from 43 pancreatic cancer patients, including 19 paired tumor-normal samples. Genotype-phenotype association studies with overall survival (in tumor only) as well as with FKBP5 gene expression were performed using the same samples in which Next Generation DNA resequencing had been performed, followed by functional genomic studies of top selected single nucleotide polymorphisms (SNPs). In-depth resequencing identified 404 FKBP5 SNPs in both normal and tumor DNA patient samples. SNPs with the smallest p-values for association with FKBP5 survival or expression were subjected to functional genomic studies. Electromobility shift assay (EMSA) showed that the rs73748206 “T” allele altered DNA-protein binding patterns, consistent with a significantly increased reporter gene activity. The effect of rs73748206 was also confirmed by mRNA expression studies using lymphoblastoid cell lines (LCL) derived from the same patients from whom DNA used for resequencing had been obtained. This comprehensive FKBP5 resequencing study provides insight into the role of inheritance in variation in response to gemcitabine therapy of pancreatic cancer. Citation Format: Katarzyna A. Ellsworth, Bruce W. Eckloff, Liang Li, Irene Moon, Brooke L. Fridley, Greg D. Jenkins, Erin Carlson, Abra Brisbin, Ryan Abo, William Bamlet, Gloria Petersen, Eric D. Wieben, Liewei Wang. Contribution of FKBP5 genetic variation to gemcitabine treatment and survival in pancreatic cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2209. doi:10.1158/1538-7445.AM2013-2209