Search

Background & aims Primary Biliary Cholangitis (PBC) is a chronic autoimmune liver disease characterized by destruction of intrahepatic bile ducts, portal inflammation and cirrhosis. Although rare in most populations, it is prevalent and often familial in British Columbia First Nations. We hypothesized that major genetic factors increased the risk in First Nations. Methods In all, 44 individuals with Primary Biliary Cholangitis and 61 unaffected relatives from 32 First Nations families participated. Family history and co-morbidities were documented. Medical records were reviewed and available biopsies were re-reviewed by our team pathologist. Genotyping was performed on DNA from 36 affected persons and 27 unaffected relatives using the Affymetrix Human Mapping 500K Array Set. MERLIN software was used to carry out multipoint parametric and nonparametric linkage analysis. Candidate genes were identified and entered into InnateDB and KEGG software to identify potential pathways affecting pathogenesis. Results In all, 34% of families were multiplex. Fifty per cent of cases and 33% of unaffected relatives reported other autoimmune disease. Three genomic regions (9q21, 17p13 and 19p13) produced LOD scores of 2.3 or greater suggestive of linkage, but no single linkage peak reached statistical significance. Candidate genes identified in the three regions suggested involvement of IL17, NFκB, IL6, JAK-STAT, IFNγ and TGFβ immune signalling pathways. Specifically, four genes-ACT1, PIN1, DNMT1 and NTN1-emerged as having roles in these pathways that may influence Primary Biliary Cholangitis pathogenesis. Conclusions Our whole genome linkage study results reflect the multifactorial nature of Primary Biliary Cholangitis, support previous studies suggesting signalling pathway involvement and identify new candidate genes for consideration.

We studied the whole-genome point mutation and structural variation patterns of 133 tumors (59 high-grade serous (HGSC), 35 clear cell (CCOC), 29 endometrioid (ENOC), and 10 adult granulosa cell (GCT)) as a substrate for class discovery in ovarian cancer. Ab initio clustering of integrated point mutation and structural variation signatures identified seven subgroups both between and within histotypes. Prevalence of foldback inversions identified a prognostically significant HGSC group associated with inferior survival. This finding was recapitulated in two independent cohorts (n = 576 cases), transcending BRCA1 and BRCA2 mutation and gene expression features of HGSC. CCOC cancers grouped according to APOBEC deamination (26%) and age-related mutational signatures (40%). ENOCs were divided by cases with microsatellite instability (28%), with a distinct mismatch-repair mutation signature. Taken together, our work establishes the potency of the somatic genome, reflective of diverse DNA repair deficiencies, to stratify ovarian cancers into distinct biological strata within the major histotypes.

We performed phylogenetic analysis of high-grade serous ovarian cancers (68 samples from seven patients), identifying constituent clones and quantifying their relative abundances at multiple intraperitoneal sites. Through whole-genome and single-nucleus sequencing, we identified evolutionary features including mutation loss, convergence of the structural genome and temporal activation of mutational processes that patterned clonal progression. We then determined the precise clonal mixtures comprising each tumor sample. The majority of sites were clonally pure or composed of clones from a single phylogenetic clade. However, each patient contained at least one site composed of polyphyletic clones. Five patients exhibited monoclonal and unidirectional seeding from the ovary to intraperitoneal sites, and two patients demonstrated polyclonal spread and reseeding. Our findings indicate that at least two distinct modes of intraperitoneal spread operate in clonal dissemination and highlight the distribution of migratory potential over clonal populations comprising high-grade serous ovarian cancers.

We carried out whole genome and transcriptome sequencing on four tumour/normal pairs of epithelioid sarcoma. These index cases were supplemented with whole transcriptome sequencing of three additional tumours and three cell lines. Unlike rhabdoid tumour (the other major group of SMARCB1-negative cancers), epithelioid sarcoma shows a complex genome with a higher mutational rate, comparable to that of ovarian carcinoma. Despite this mutational burden, SMARCB1 mutations remain the most frequently recurring event and are probably critical drivers of tumour formation. Several cases show heterozygous SMARCB1 mutations without inactivation of the second allele, and we explore this further in vitro. Finding CDKN2A deletions in our discovery cohort, we evaluated CDKN2A protein expression in a tissue microarray. Six out of 16 cases had lost CDKN2A in greater than or equal to 90% of cells, while the remaining cases had retained the protein. Expression analysis of epithelioid sarcoma cell lines by transcriptome sequencing shows a unique profile that does not cluster with any particular tissue type or with other SWI/SNF-aberrant lines. Evaluation of the levels of members of the SWI/SNF complex other than SMARCB1 revealed that these proteins are expressed as part of a residual complex, similarly to previously studied rhabdoid tumour lines. This residual SWI/SNF is susceptible to synthetic lethality and may therefore indicate a therapeutic opportunity.

Characterization and quantification of tumour clonal populations over time via longitudinal sampling are essential components in understanding and predicting the response to therapeutic interventions. Computational methods for inferring tumour clonal composition from deep-targeted sequencing data are ubiquitous, however due to the lack of a ground truth biological data, evaluating their performance is difficult. In this work, we generate a benchmark data set that simulates tumour longitudinal growth and heterogeneity by in vitro mixing of cancer cell lines with known proportions. We apply four different algorithms to our ground truth data set and assess their performance in inferring clonal composition using different metrics. We also analyse the performance of these algorithms on breast tumour xenograft samples. We conclude that methods that can simultaneously analyse multiple samples while accounting for copy number alterations as a factor in allelic measurements exhibit the most accurate predictions. These results will inform future functional genomics oriented studies of model systems where time series measurements in the context of therapeutic interventions are becoming increasingly common. These studies will need computational models which accurately reflect the multi-factorial nature of allele measurement in cancer including, as we show here, segmental aneuploidies.

The evolution of cancer genomes within a single tumor creates mixed cell populations with divergent somatic mutational landscapes. Inference of tumor subpopulations has been disproportionately focused on the assessment of somatic point mutations, whereas computational methods targeting evolutionary dynamics of copy number alterations (CNA) and loss of heterozygosity (LOH) in whole-genome sequencing data remain underdeveloped. We present a novel probabilistic model, TITAN, to infer CNA and LOH events while accounting for mixtures of cell populations, thereby estimating the proportion of cells harboring each event. We evaluate TITAN on idealized mixtures, simulating clonal populations from whole-genome sequences taken from genomically heterogeneous ovarian tumor sites collected from the same patient. In addition, we show in 23 whole genomes of breast tumors that the inference of CNA and LOH using TITAN critically informs population structure and the nature of the evolving cancer genome. Finally, we experimentally validated subclonal predictions using fluorescence in situ hybridization (FISH) and single-cell sequencing from an ovarian cancer patient sample, thereby recapitulating the key modeling assumptions of TITAN.

Background Follicular lymphoma (FL) is an indolent, yet incurable B cell malignancy. A subset of patients experience an increased mortality rate driven by two distinct clinical end points: histological transformation and early progression after immunochemotherapy. The nature of tumor clonal dynamics leading to these clinical end points is poorly understood, and previously determined genetic alterations do not explain the majority of transformed cases or accurately predict early progressive disease. We contend that detailed knowledge of the expansion patterns of specific cell populations plus their associated mutations would provide insight into therapeutic strategies and disease biology over the time course of FL clinical histories. Methods and Findings Using a combination of whole genome sequencing, targeted deep sequencing, and digital droplet PCR on matched diagnostic and relapse specimens, we deciphered the constituent clonal populations in 15 transformation cases and 6 progression cases, and measured the change in clonal population abundance over time. We observed widely divergent patterns of clonal dynamics in transformed cases relative to progressed cases. Transformation specimens were generally composed of clones that were rare or absent in diagnostic specimens, consistent with dramatic clonal expansions that came to dominate the transformation specimens. This pattern was independent of time to transformation and treatment modality. By contrast, early progression specimens were composed of clones that were already present in the diagnostic specimens and exhibited only moderate clonal dynamics, even in the presence of immunochemotherapy. Analysis of somatic mutations impacting 94 genes was undertaken in an extension cohort consisting of 395 samples from 277 patients in order to decipher disrupted biology in the two clinical end points. We found 12 genes that were more commonly mutated in transformed samples than in the preceding FL tumors, including TP53, B2M, CCND3, GNA13, S1PR2, and P2RY8. Moreover, ten genes were more commonly mutated in diagnostic specimens of patients with early progression, including TP53, BTG1, MKI67, and XBP1. Conclusions Our results illuminate contrasting modes of evolution shaping the clinical histories of transformation and progression. They have implications for interpretation of evolutionary dynamics in the context of treatment-induced selective pressures, and indicate that transformation and progression will require different clinical management strategies., Sohrab Shah and colleagues explore the evolutionary histories that shape clinical and transformation dynamics in follicular lymphoma, Author Summary Why Was This Study Done? Follicular lymphoma (FL) is a largely incurable malignancy in which early progression and transformation have consistently been linked to lymphoma-related mortality. We contended that detailed characterization of clonal dynamics would reveal fundamental biological properties with implications for future patient management strategies relating to both transformation and progression. We also sought to identify recurrent gene mutations associated with transformation and/or early progression in a large patient cohort. What Did the Researchers Do and Find? Using whole genome sequencing, deep allelic sampling by amplicon sequencing, and digital droplet PCR, we found dramatic clonal expansions in transformed disease, whereby dominant clones in transformation samples emerged from extremely low prevalence clones or from clones that were not detected in the diagnostic samples. The dynamics of disease progression during treatment in the absence of transformation showed markedly different characteristics, with much of the clonal architecture preserved from diagnostic to relapse specimens. Targeted capture-based sequencing in a large extension cohort then established genetic variants associated with transformation and early progression in the broader patient population. What Do These Findings Mean? Taken together, our findings illuminate previously undescribed patterns of clonal expansion underpinning FL clinical histories suggesting that contrasting management strategies will be necessary across the FL patient population. We uncovered novel associations of gene mutations with early progression that could inform future prognostic assay development.

Cystic fibrosis (CF) is one of the most common life-shortening genetic disorders, and the CF transmembrane conductance regulator (CFTR) is the major causal gene. However, a substantial clinical variability among patients with identical CFTR genotypes suggests the presence of modifier genes. We tested the effect of four genes involved in Pseudomonas aeruginosa infection. Analysis of a primary cohort detected eight candidate polymorphisms that were genotyped in the secondary cohort of 1579 patients; lung function and age at first infection with P. aeruginosa were considered as the phenotypes. Both additive and codominant models were considered, adjusting for confounding variables but not for multiple comparisons. In the secondary cohort, heme oxygenase-1 (HMOX1) rs2071749 had the most significant effect on lung function in the pediatric group (P=0.01; P(corrected)=0.03), and complement factor 3 (C3) rs11569393 and HMOX1 rs2071746 in the adult groups (P=0.03 for both variants; P(corrected)=0.16, 0.09). No polymorphism of complement factor B (CFB) or toll-like receptor 4 (TLR4) had a significant modifying effect on lung function in either group. We have identified two genes that showed nominal association with disease severity among CF patients. However, because of the multiple comparisons made, further studies are required to confirm the interaction between these modifying genes and CFTR.

Background: Interleukin-6 (IL6) is a pleiotropic pro-inflammatory and immunomodulatory cytokine which probably plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). There is a functional single nucleotide polymorphism (SNP), -174G/C, in the promoter region of IL6 . It was hypothesised that IL6 SNPs influence susceptibility for impaired lung function and COPD in smokers. Methods: Seven and five SNPs in IL6 were genotyped in two nested case-control samples derived from the Lung Health Study (LHS) based on phenotypes of rate of decline of forced expiratory volume in 1 s (FEV1) over 5 years and baseline FEV1 at the beginning of the LHS. Serum IL6 concentrations were measured for all subjects. A partially overlapping panel of nine IL6 SNPs was genotyped in 389 cases of COPD from the National Emphysema Treatment Trial (NETT) and 420 controls from the Normative Aging Study (NAS). Results: In the LHS, three IL6 SNPs were associated with decline in FEV1 (0.023⩽p⩽0.041 in additive models). Among them, the IL6 \_-174C allele was associated with a rapid decline in lung function. The association was more significant in a genotype-based analysis (p = 0.006). In the NETT-NAS study, IL6 \_-174G/C and four other IL6 SNPs, all of which are in linkage disequilibrium with IL6 _-174G/C, were associated with susceptibility to COPD (0.01⩽p⩽0.04 in additive genetic models). Conclusion: The results suggest that the IL6 _-174G/C SNP is associated with a rapid decline in FEV1 and susceptibility to COPD in smokers.

Granulocyte-macrophage colony-stimulating factor (CSF), also known as CSF2, and granulocyte CSF, also known as CSF3, are important survival and proliferation factors for neutrophils and macrophages. The objective of the present study was to determine whether single nucleotide polymorphisms (SNPs) of CSF2 and CSF3 are associated with lung function in smoking-induced chronic obstructive pulmonary disease. In total, five SNPs of CSF2 and CSF3 were studied in 587 non-Hispanic white subjects with the fastest (n = 281) or the slowest (n = 306) decline of lung function selected from among continuous smokers in the National Heart, Lung, and Blood Institute Lung Health Study (LHS). These SNPs were also studied in 1,074 non-Hispanic white subjects with the lowest (n = 536) or the highest (n = 538) baseline lung function at the beginning of the LHS. An increase in the number of CSF3 -1719T alleles was significantly associated with protection against low lung function (odds ratio 0.73, 95% confidence interval 0.56-0.95), and was still significant after adjustment for multiple comparisons. There was also a significant association of a CSF3 haplotype with baseline levels of forced expiratory volume in one second. No association was found for CSF2 SNPs and lung function, nor was there evidence of epistasis. In conclusion, genetic variation in colony-stimulating factor 3 is associated with cross-sectionally measured lung function in smokers.

Non–Hodgkin lymphoma (NHL) comprises a group of lymphoid tumors that have in common somatic translocations. H2AFX encodes a key histone involved in the detection of the DNA double-stranded breaks that can lead to translocations. H2afx is a dosage-dependent gene that protects against B-cell lymphomas in mice, making its human orthologue an ideal candidate gene for susceptibility to lymphoma. We did a population-based genetic association study of H2AFX variants in 487 NHL cases and 531 controls. Complete resequencing of the human H2AFX gene in 95 NHL cases was done to establish the spectrum of variation in affected individuals; this was followed by both direct and indirect tests for association at the level of individual single nucleotide polymorphisms (SNP) and as haplotypes. Homozygosity for the AA genotype of a SNP 417 bp upstream of the translational start of H2AFX is strongly associated [odds ratio (OR), 0.54; P = 0.001] with protection from NHL. We find a strong association of this SNP with the follicular lymphoma subtype of NHL (AA genotype: OR, 0.40; P = 0.004) and with mantle cell lymphoma (AA genotype: OR, 0.20; P = 0.01) that remains significant after adjustment for the false discovery rate, but not with diffuse large B-cell lymphoma. These data support the hypothesis that genetic variation in the H2AFX gene influences genetic susceptibility or resistance to some subtypes of NHL by contributing to the maintenance of genome stability. (Cancer Epidemiol Biomarkers Prev 2007;16(6):1098–106)

Interleukin (IL)-10 is a type-2 T-helper cell cytokine with a broad spectrum of anti-inflammatory actions. Inflammation plays an important role in the pathogenesis of chronic obstructive pulmonary disease. It was hypothesised that single nucleotide polymorphisms (SNPs) of the genes encoding IL-10 ( IL10 ) and the α subunit of its receptor ( IL10RA ) are associated with changes in, or value of, forced expiratory volume in one second (FEV 1 ) in smoking-induced chronic obstructive pulmonary disease. In total, eleven SNPs of IL10 and IL10RA were studied in 586 White subjects, selected from continuous smokers followed for 5 yrs in the Lung Health Study, who showed the fastest (n = 280) and slowest (n = 306) decline in FEV 1 . These 11 SNPs were also studied in 1,072 participants exhibiting the lowest (n = 538) and highest (n = 534) baseline FEV 1 at the beginning of the Lung Health Study. No association was found in the primary analyses. Although a subgroup analysis showed that the IL-10 3368A allele was associated with a fast decline in FEV 1 , the association did not pass correction for multiple comparisons. No gene–gene interaction of IL10 with IL10RA was found. There was no association of polymorphisms of the genes encoding interleukin-10 and the α subunit of its receptor with the rate of decline in, or value of, forced expiratory volume in one second in smoking-induced chronic obstructive pulmonary disease.

Circulating tumour DNA analysis can be used to track tumour burden and analyse cancer genomes non-invasively but the extent to which it represents metastatic heterogeneity is unknown. Here we follow a patient with metastatic ER-positive and HER2-positive breast cancer receiving two lines of targeted therapy over 3 years. We characterize genomic architecture and infer clonal evolution in eight tumour biopsies and nine plasma samples collected over 1,193 days of clinical follow-up using exome and targeted amplicon sequencing. Mutation levels in the plasma samples reflect the clonal hierarchy inferred from sequencing of tumour biopsies. Serial changes in circulating levels of sub-clonal private mutations correlate with different treatment responses between metastatic sites. This comparison of biopsy and plasma samples in a single patient with metastatic breast cancer shows that circulating tumour DNA can allow real-time sampling of multifocal clonal evolution., Individual tumours are heterogeneous with regards to genetic mutations. In this study, the authors use sequencing to follow multiple tumour and plasma samples over 3 years from a breast cancer patient and show mutations detected in the plasma samples could partially reproduce the clonal nature of the primary tumour.

Importance E-cadherin ( CDH1 ) is a cancer predisposition gene mutated in families meeting clinically defined hereditary diffuse gastric cancer (HDGC). Reliable estimates of cancer risk and spectrum in germline mutation carriers are essential for management. For families without CDH1 mutations, genetic-based risk stratification has not been possible, resulting in limited clinical options. Objectives To derive accurate estimates of gastric and breast cancer risks in CDH1 mutation carriers and determine if germline mutations in other genes are associated with HDGC. Design, Setting, and Participants Testing for CDH1 germline mutations was performed on 183 index cases meeting clinical criteria for HDGC. Penetrance was derived from 75 mutation-positive families from within this and other cohorts, comprising 3858 probands (353 with gastric cancer and 89 with breast cancer). Germline DNA from 144 HDGC probands lacking CDH1 mutations was screened using multiplexed targeted sequencing for 55 cancer-associated genes. Main Outcomes and Measures Accurate estimates of gastric and breast cancer risks in CDH1 mutation carriers and the relative contribution of other cancer predisposition genes in familial gastric cancers. Results Thirty-one distinct pathogenic CDH1 mutations (14 novel) were identified in 34 of 183 index cases (19%). By the age of 80 years, the cumulative incidence of gastric cancer was 70% (95% CI, 59%-80%) for males and 56% (95% CI, 44%-69%) for females, and the risk of breast cancer for females was 42% (95% CI, 23%-68%). In CDH1 mutation–negative index cases, candidate mutations were identified in 16 of 144 probands (11%), including mutations within genes of high and moderate penetrance: CTNNA1 , BRCA2 , STK11 , SDHB , PRSS1 , ATM , MSR1 , and PALB2 . Conclusions and Relevance This is the largest reported series of CDH1 mutation carriers, providing more precise estimates of age-associated risks of gastric and breast cancer that will improve counseling of unaffected carriers. In HDGC families lacking CDH1 mutations, testing of CTNNA1 and other tumor suppressor genes should be considered. Clinically defined HDGC families can harbor mutations in genes (ie, BRCA2) with different clinical ramifications from CDH1 . Therefore, we propose that HDGC syndrome may be best defined by mutations in CDH1 and closely related genes, rather than through clinical criteria that capture families with heterogeneous susceptibility profiles.

The development of targeted anti-cancer therapies through the study of cancer genomes is intended to increase survival rates and decrease treatment-related toxicity. We treated a transposon-driven, functional genomic mouse model of medulloblastoma with 'humanized' in vivo therapy (microneurosurgical tumour resection followed by multi-fractionated, image-guided radiotherapy). Genetic events in recurrent murine medulloblastoma exhibit a very poor overlap with those in matched murine diagnostic samples (

We studied the role of multiple biomarkers in determining outcome in follicular lymphoma (FL), concentrating in particular on the role of benign macrophages. The study group consisted of uniformly staged and treated patients with FL enrolled in a phase 2 trial between 1987 and 1993. All patients were younger than 61 years of age, had advanced-stage FL, and were treated with a multiagent chemotherapy regimen, BP-VACOP (bleomycin, cisplatin, etoposide, doxorubicin, cyclophosphamide, vincristine, and prednisone), followed by involved region radiation. The median follow-up of living patients was 12.5 years, and the median survival was 16.3 years. The International Prognostic Index (IPI) was predictive of overall survival (OS) (P = .003). Biopsy specimens from all cases were stained with an anti-CD68 antibody. Of the 99 evaluable patients with FL, 87 had less than 15 CD68+ macrophages/high-power field (hpf) (median, 7; range, 1-14) and 12 had more than 15 CD68+ macrophages/hpf (median, 20; range, 16-25) with a median OS of 16.3 vs 5.0 years, respectively (P < .001). A multivariate Cox model that included the IPI score, the histologic grade, and the lymphoma-associated macrophage (LAM) score, showed IPI and LAM to be independent predictors of OS (P = .009 and P = .004, respectively). The LAM content of FL predicts survival, and these data support a prominent role for nonneoplastic immune cells in the biology of FL. (Blood. 2005;106:2169-2174)

Small cell carcinoma of the ovary of hypercalcemic type (SCCOHT) is an extremely rare, aggressive cancer affecting children and young women. We identified germline and somatic inactivating mutations in the SWI/SNF chromatin-remodeling gene SMARCA4 in 75% (9/12) of SCCOHT cases in addition to SMARCA4 protein loss in 82% (14/17) of SCCOHT tumors but in only 0.4% (2/485) of other primary ovarian tumors. These data implicate SMARCA4 in SCCOHT oncogenesis.

Deep-genome and single-cell sequencing analyses of patient-derived breast cancer xenografts reveal extensive, dynamic and reproducible changes in intra-tumoral mutational clonal composition on engraftment and serial propagation. Xenograft transplantation of primary human cancer cells into mice provides valuable models in which to study mechanisms underlying tumorigenesis, drug response and resistance. This study demonstrates that clonal evolution resembling that seen in human tumours also occurs on engraftment and during subsequent passaging of breast tumours in immunodeficient mice. In addition, similar clonal expansion patterns emerge in independent grafts of the same starting tumour population, indicating that genomic aberrations can be reproducible determinants of evolutionary trajectories. These findings suggest that patient-derived xenografts may be useful for studying patient-specific tumour characteristics such as the response to drugs tailored to specific genomic alterations. Human cancers, including breast cancers, comprise clones differing in mutation content. Clones evolve dynamically in space and time following principles of Darwinian evolution1,2, underpinning important emergent features such as drug resistance and metastasis3,4,5,6,7. Human breast cancer xenoengraftment is used as a means of capturing and studying tumour biology, and breast tumour xenografts are generally assumed to be reasonable models of the originating tumours8,9,10. However, the consequences and reproducibility of engraftment and propagation on the genomic clonal architecture of tumours have not been systematically examined at single-cell resolution. Here we show, using deep-genome and single-cell sequencing methods, the clonal dynamics of initial engraftment and subsequent serial propagation of primary and metastatic human breast cancers in immunodeficient mice. In all 15 cases examined, clonal selection on engraftment was observed in both primary and metastatic breast tumours, varying in degree from extreme selective engraftment of minor (

Alveolar macrophages play an important role in chronic obstructive pulmonary disease via production of matrix metalloproteinases (MMPs) and cathepsins as well as their inhibitors, tissue inhibitors of metalloproteinases and cystatin C. We hypothesised that expression levels of these molecules by alveolar macrophages at baseline and after stimulation would be influenced by genotype and associated with chronic obstructive pulmonary disease phenotypes. Quantitative PCR and ELISAs/gelatine zymography were used to investigate expression levels of mRNA and protein, respectively. The relationships of expression with genotype, pulmonary function and emphysema were analysed. The results showed that basal expression level of MMP12 mRNA was inversely related to the diffusing capacity of the lung for carbon monoxide/alveolar volume and to forced expiratory volume in 1 s/forced vital capacity after correction for multiple comparisons. The expression level of MMP12 protein stimulated with lipopolysaccharide was also inversely related to the diffusing capacity of the lung for carbon monoxide/alveolar volume and was positively related to the extent of emphysema. The basal expression of MMP1 mRNA was positively correlated with the extent of emphysema. Cathepsin L protein level was positively associated with forced expiratory volume in 1 s % predicted. We conclude that increased MMP12 and MMP1 expression may play a role in the pathogenesis of emphysema. Cathepsin L and MMP9 may be involved in the development of airflow limitation.

Background Ovarian carcinomas consist of at least five distinct diseases: high-grade serous, low-grade serous, clear cell, endometrioid, and mucinous. Biomarker and molecular characterization may represent a more biologically relevant basis for grouping and treating this family of tumors, rather than site of origin. Molecular characteristics have become the new standard for clinical pathology, however development of tailored type-specific therapies is hampered by a failure of basic research to recognize that model systems used to study these diseases must also be stratified. Unrelated model systems do offer value for study of biochemical processes but specific cellular context needs to be applied to assess relevant therapeutic strategies. Methods We have focused on the identification of clear cell carcinoma cell line models. A panel of 32 “ovarian cancer” cell lines has been classified into histotypes using a combination of mutation profiles, IHC mutation-surrogates, and a validated immunohistochemical model. All cell lines were identity verified using STR analysis. Results Many described ovarian clear cell lines have characteristic mutations (including ARID1A and PIK3CA) and an overall molecular/immuno-profile typical of primary tumors. Mutations in TP53 were present in the majority of high-grade serous cell lines. Advanced genomic analysis of bona-fide clear cell carcinoma cell lines also support copy number changes in typical biomarkers such at MET and HNF1B and a lack of any recurrent expressed re-arrangements. Conclusions: As with primary ovarian tumors, mutation status of cancer genes like ARID1A and TP53 and a general immuno-profile serve well for establishing histotype of ovarian cancer cell We describe specific biomarkers and molecular features to re-classify generic “ovarian carcinoma” cell lines into type specific categories. Our data supports the use of prototype clear cell lines, such as TOV21G and JHOC-5, and questions the use of SKOV3 and A2780 as models of high-grade serous carcinoma.

Introduction: Follicular lymphoma (FL) remains a significant clinical burden as it is an incurable disease and most patients will eventually suffer from disease progression. Two clinical events are associated with poor outcomes for patients with FL: (1) histological transformation (TFL) of their original FL into a high-grade, aggressive lymphoma subtype (2-3% of patients per year) and (2) early disease progression (PFL) where patients experience treatment failure within 2 years of receiving therapy (20% of patients). Despite recent high-throughput sequencing studies, the nature of tumor clonal dynamics leading to TFL or PFL is poorly understood and it is unknown if similar, or contrasting, modes of selection underpin these FL clinical events. Materials & Methods:We assembled a study cohort consisting of 21 patients: 15 experiencing TFL and 6 PFL. For each TFL and PFL patient, we obtained primary biopsies (T1; taken at the time of the initial FL diagnosis), biopsies at transformation/progression (T2) and matched normal samples. We performed whole genome sequencing on each specimen and identified single point mutations and copy number alterations using MutationSeq and TITAN, respectively. We compared T1 to T2 somatic mutation profiles and identified mutations associated with extinction of T1 clones and expansion of T2 clones. To validate these patterns, we selected 192 positions from each patient for deep-targeted sequencing validation (~10733X) in their T1, T2, and normal samples. We applied a statistical model (PyClone) to estimate cancer cell fraction (CCF) of each validated mutation. These CCF estimates were used to construct clonal phylogenies (Citup) and infer clonal dynamic patterns during their evolutionary histories. The Wright-Fisher model of genetic drift was used to model tumor evolution. Results: Temporal analysis of mutational burden revealed that mutational burden was significantly higher in T2 (8162 mutations ± 2146) than in T1 (6373 ± 2630) tumors for both TFL and PFL patients (Wilcox P < 0.001). This was independent of time interval between sampling (Spearman R2 = 0.029, P = 0.456). Mutation variant allelic fraction (VAF) distributions revealed that all distributions showed evidence of shared clonal ancestry between T1 and T2 tumors accompanied by substantial numbers of T1 and T2-specific mutations. We selected ≥ 192 mutations per patient from these distributions and performed deep-targeted amplicon sequencing, validating 96.3% of mutations and acquiring precise VAFs to infer clonal dynamics. In 13 of 15 TFL patients (87%), we observed dramatic clonal dynamics, characteristic of T2 tumors dominated by clones (or phylogenetic lineages) that were absent or extremely rare in T1 tumors (< 1% CCF). Digital droplet PCR was used to confirm the existence of both scenarios (confirming a clone as rare as 2 out of approximately 105 cells). Tumor evolution modeling demonstrated that this mode of evolution was driven through positive selection for mutations that confer fitness advantages and not by genetic drift. In contrast, PFL patients exhibited markedly different patterns of clonal dynamics compared to TFL patients. 4 of 6 PFL patients (67%) harbored readily detectable clones at T1, which expanded to full clonal prevalence during treatment with immuno-chemotherapy. Tumor evolution modeling demonstrated that this mode of evolution could be explained under neutral evolutionary dynamics (drift). Conclusions: We have shown that histological transformation and early progression manifest through divergent modes of tumor evolution. As the transformation phenotype may arise after diagnosis, more frequent monitoring of these patients will be required to determine the exact timing of the evolutionary inflection point that elicits transformation. In comparison, prediction of early treatment resistance should be achievable through comprehensive characterization of the genetic and clonal composition at diagnosis; this would ultimately identify patients who may benefit from upfront alternative therapies without the need to first endure predictable early treatment failure. Disclosures Sehn: roche/genentech: Consultancy, Honoraria; amgen: Consultancy, Honoraria; seattle genetics: Consultancy, Honoraria; abbvie: Consultancy, Honoraria; TG therapeutics: Consultancy, Honoraria; celgene: Consultancy, Honoraria; lundbeck: Consultancy, Honoraria; janssen: Consultancy, Honoraria. Connors:Millennium Takeda: Research Funding; Seattle Genetics: Research Funding; F Hoffmann-La Roche: Research Funding; Bristol Myers Squib: Research Funding; NanoString Technologies: Research Funding. Scott:Janssen: Consultancy; Celgene: Consultancy; Roche: Honoraria; BC Cancer Agency: Patents & Royalties: Inventor on a patent licensed to NanoString Technologies.

Primary triple negative breast cancers (TNBC) represent approximately 16% of all breast cancers1 and are a tumour type defined by exclusion, for which comprehensive landscapes of somatic mutation have not been determined. Here we show in 104 early TNBC cases, that at the time of diagnosis these cancers exhibit a wide and continuous spectrum of genomic evolution, with some exhibiting only a handful of somatic aberrations in a few pathways, whereas others contain hundreds of somatic events and multiple pathways implicated. Integration with matched whole transcriptome sequence data revealed that only ~36% of mutations are expressed. By examining single nucleotide variant (SNV) allelic abundance derived from deep re-sequencing (median >20,000 fold) measurements in 2414 somatic mutations, we determine for the first time in an epithelial tumour, the relative abundance of clonal genotypes among cases in the population. We show that TNBC vary widely and continuously in their clonal frequencies at the time of diagnosis, with basal subtype TNBC2,3 exhibiting more variation than non-basal TNBC. Although p53 and PIK3CA/PTEN somatic mutations appear clonally dominant compared with other pathways, in some tumours their clonal frequencies are incompatible with founder status. Mutations in cytoskeletal and cell shape/motility proteins occurred at lower clonal frequencies, suggesting they occurred later during tumour progression. Taken together our results show that future attempts to dissect the biology and therapeutic responses of TNBC will require the determination of individual tumour clonal genotypes.

Introduction: Small cell carcinoma of the ovary of hypercalcemic type (SCCOHT) is arguably the most aggressive ovarian cancer. Most patients are diagnosed at an advanced stage, do not respond to chemotherapy, and die of disease within 1-2 years. It affects children and young women and is reported to occur in families. The cause of the disease is poorly understood. Therefore, we used next generation sequencing technology to identify the genetic basis of the disease. Method: We performed whole genome, whole exome sequencing or targeted sequencing on tumours and germline samples from 17 SCCOHT patients and on the SCCOHT cell line BIN-67 and SCCOHT-1. Immunohistochemistry (IHC) was performed on formalin-fixed, paraffin-embedded tumors from 23 patients and on a tissue microarray of 485 primary ovarian tumours of other subtypes. BIN-67 cells harbouring biallelic inactivation of SMARCA4 were transduced with a lentivirus expressing wild type SMARCA4. Result: We identified inactivating germline and somatic mutations in the SWI/SNF chromatin-remodeling gene SMARCA4 in 79% (11/14) of SCCOHT patients, 2 of whom bore germline mutations, and in both cell lines. SMARCA4 protein was lost in 87% (20/23) of SCCOHT tumours but in only 0.4% (2/485) of other primary ovarian tumours. Reintroduction of wild-type SMARCA4 into BIN-67 cells resulted in altered cell morphology and growth arrest. Conclusions: The mutation spectrum, IHC profile and cell culture phenotype implicate SMARCA4 as a critical tumour suppressor in SCCOHT pathogenesis. Citation Format: Pilar Ramos, Anthony N. Karnezis, David W. Craig, Aleksandar Sekulic, Megan L. Russell, William P.D. Hendricks, Jason J. Corneveaux, Michael T. Barrett, Karey Shumansky, Yidong Yang, Sohrab P. Shah, Leah M. Prentice, Marco A. Marra, Jeffrey Kiefer, Victoria L. Zismann, Troy A. McEachron, Bodour Salhia, Jaime Prat, Blaise A. Clarke, Joseph G. Pressey, John H. Farley, Stephen P. Anthony, Richard B.S. Roden, Heather E. Cunliffe, David G. Huntsman, Jeffrey M. Trent. Small cell carcinoma of the ovary, hypercalcemic type displays frequent inactivating germline and somatic mutations in SMARCA4 [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1327.

Importance. Hereditary gastric cancer (HGC) is a rare, autosomal dominant susceptibility syndrome characterized either by early onset diffuse gastric cancer and lobular breast cancer or aggregates of intestinal gastric cancer. The genetic etiology of Objectives. 1) Determine whether pathogenic germline mutations in genes related to upper gastrointestinal disorders (UGI) are causative in HGC and 2) show that a targeted multiplexed next generation sequencing approach is effective and efficient for detecting such mutations. Methods & Participants. 115 probands from families who met clinical criteria for HDGC (n=108) or FIGC (n=7) were included. HDGC participants have all previously tested negative for CDH1 variants. A custom panel of 55 genes previously associated with heritable UGI disorders was designed through literature research and collaborative efforts. The germline DNA of probands from each family was sequenced for all targeted regions using the MiSeq platform. Candidate variants were selected based on likelihood of pathogenicity (protein truncating, rare/novel pathogenic missense variants) then validated via Sanger sequencing. Tumour materials from mutation-carriers were analyzed for loss of heterozygosity via immunohistochemistry and/or second hit analysis. When available, germline DNA of additional family members was collected for segregation analysis. Results. We have identified clearly pathogenic mutations in unrelated HGC families, including two protein truncating mutations each in CTNNA1 and BRCA2 genes and two rare, pathogenic missense mutations each in SDHB and STK11 genes. Additional protein truncating mutations were identified in moderately penetrant genes ATM (4 families), MSR1 (2 families), and PALB2 (1 family). Overall, 13% of families included in this study were found to have pathogenic (8) or likely pathogenic (7) mutations in genes included on our custom panel. Tumour material was available from probands with truncating CTNNA1 variants, revealing distinct loss of protein expression using immunohistochmistry. This further supports the likelihood of pathogenicity. Conclusion & Relevance. Using a targeted next generation sequencing approach that significantly reduced sequencing cost while simultaneously improving turn-around time, we show that HGC families can carry pathogenic mutations outside the CDH1-locus, including genes commonly associated with other UGI syndromes. The genetic basis of the remaining families likely lies in yet to be discovered susceptibility genes or, in the case of HDGC, additional abnormalities at the CDH1-locus. Citation Format: Samantha Hansford, Hector LiChang, Pardeep Kaurah, Michelle Woo, Karey Shumansky, David F. Schaeffer, Giovanni Corso, George Zogopoulos, Steven Gallinger, Hugo Pinheiro, Franco Roviello, Carla Oliveira, David Huntsman. Genetic basis of hereditary gastric cancer: Beyond the CDH1 locus. [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 1282. doi:10.1158/1538-7445.AM2014-1282

Small Cell Carcinoma of the Ovary Hypercalcemic Type (SCCOHT) is a rare and highly aggressive malignancy that affects children and young women at a mean age of 24 (range 14 months - 58 years). SCCOHT is refractory to standard of care therapy for ovarian cancer, with ∼75% mortality within 18 months of diagnosis. The early age of onset of SCCOHT and reports of familial occurrence in some cases, strongly suggest an underlying hereditary etiology. To understand the molecular pathogenesis of SCCOHT, we performed next-generation genomic sequencing on a series of tumor and germline samples from SCCOHT patients. This analysis revealed germline and somatic inactivating mutations in SMARCA4, a subunit of the SWI/SNF chromatin-remodeling complex, in 75% (9/12) of SCCOHT patients. Moreover, immunohistochemical (IHC) analysis of 15 tumors revealed that 87% (13/15) of tumors lacked SMARCA4 protein. The high prevalence of SMARCA4 mutations in SCCOHT has not been previously reported in other, more common ovarian carcinomas. We therefore examined the expression of SMARCA4 protein in 300 ovarian carcinomas of different histologies by IHC and found SMARCA4 protein loss in only 6 tumors. In addition, the BIN-67 SCCOHT cell line, which harbors 2 splice site mutations in SMARCA4, showed complete absence of SMARCA4 protein by Western blot while representative cell lines from 4 other ovarian carcinoma subtypes as well as immortalized granulosa cells (SVOG) and adult granulosa tumor cells (KGN) all maintained SMARCA4 expression. The prevalence of germline and sporadic SMARCA4 mutations as well as frequent SMARCA4 protein loss in SCCOHTs implicates this gene as a tumor suppressor in this cancer and more broadly suggests a role for the SWI/SNF complex in its pathogenesis. In addition to providing evidence to the pathogenesis of SCCOHT, this finding provides the opportunity to develop treatment approaches for SCCOHT based on targeting vulnerabilities of SMARCA4-deficient cells. Citation Format: Pilar Ramos, Anthony Karnezis, David Craig, Aleksandar Sekulic, Megan Russell, William Hendricks, Michael Barrett, Karey Shumansky, Yidong Yang, Sohrab Shah, Leah Prentice, Marco Marra, Jeffrey Kiefer, Victoria Zismann, Troy McEachron, Bodour Salhia, Joseph Pressey, John Farley, Stephen Anthony, Richard Roden, Heather Cunliffe, David Huntsman, Jeffrey Trent. The rare, highly malignant small cell carcinoma of the ovary displays common inactivating germline and somatic mutations in the tumor suppressor SMARCA4. [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 LB-202. doi:10.1158/1538-7445.AM2014-LB-202

Background: FL displays a diverse spectrum of clinical behavior as evidenced by marked variability in patient survival. Biological prognostic markers predictive of overall survival (OS) are mostly lacking. Recent work by the Leukemia Lymphoma Molecular Profiling Project (LLMPP) demonstrated that non-neoplastic cells in FL biopsy samples were important for determining outcome in FL and were integral to the design of a molecular gene expression survival predictor (Dave et al, Blood 102; #11: A617, ASH 2003, in press). We examined the role of immune cells as prognostic markers in FL. Methods: Between 1987 and 1993, the BC Cancer Agency enrolled 126 patients with FL on a phase II study of BP-VACOP and involved region radiotherapy. All patients were treatment naïve, < 61 y of age and had advanced-stage FL. Of these cases, paraffin blocks were available for tissue microarray (TMA) construction for 105 patients. The TMAs consisted of duplicate 1.0mm cores of diagnostic biopsies and were all screened with CD20 antibodies to ensure tumor cell content. The TMAs were immunostained for CD20, CD3, CD4, CD7, CD8, CD57, MIB1, CD21, TIA1 and CD68. Immuno-architectural patterns and numbers of cells per 1,000X field (hpf) were determined. OS was determined and a Cox multivariate model was constructed. Results: 99/105 cases were successfully arrayed and comprise the study group. The median follow-up of the 55 living patients was 12.5 y. The median OS was 16.5 y. Histologic FL grade (WHO): grade1 (n=77), grade 2 (n=15) and grade 3A (n=7). 15 patients had marginal zone differentiation. In univariate analysis the IPI was predictive of OS (p = 0.003). Of the 99 evaluable FL cases, 87 had < 15 CD68+ macrophages/hpf (median 7 [range 1–14]) and 12 had > 15 macrophages/hpf (median 20 [range 16–25]) with median OS being 16.3 y vs 5.0 y, respectively (p = 0.0003). None of the pathology variables were predictive of OS in univariate analysis with the exception of the CD68 score, equivalent to LAM. There was no relationship between proliferation and the LAM score. In accordance, the CD68+ cells did not appear to be predominantly phagocytic. The macrophages were both within and between neoplastic follicles. A Cox multivariate model showed that IPI and CD68/LAM score were independent variables (p = 0.009 and p = 0.001, respectively). Figure Figure Conclusions: The LAM score is an important independent prognostic factor in advanced-stage FL patients treated uniformly with an aggressive treatment regimen that included multi-agent chemotherapy and radiation. Numbers and distribution of T cell subsets and patterns of follicular dendritic cells were not predictive in this cohort. CD68+ macrophages/LAM may be a surrogate for an important component of the “immune response-2” gene expression signature, previously associated with inferior OS by the LLMPP consortium. LAM may allow improved stratification of FL for treatment purposes and importantly, understanding the role of macrophages in FL may provide insights into new targets for immune-based or other novel therapies.

Background Oxidative stress induced by smoking is considered to be important in the pathogenesis of Chronic Obstructive Pulmonary Disease (COPD). Heme oxygenase-1 (HMOX1) is an essential enzyme in heme catabolism that is induced by oxidative stress and may play a protective role as an antioxidant in the lung. We determined whether HMOX1 polymorphisms were associated with lung function in COPD patients and whether the variants had functional effects. Methods We genotyped five single nucleotide polymorphisms (SNPs) in the HMOX1 gene in Caucasians who had the fastest (n = 278) and the slowest (n = 304) decline of FEV1 % predicted, selected from smokers in the NHLBI Lung Health Study. These SNPs were also studied in Caucasians with the lowest (n = 535) or the highest (n = 533) baseline lung function. Reporter genes were constructed containing three HMOX1 promoter polymorphisms and the effect of these polymorphisms on H2O2 and hemin-stimulated gene expression was determined. The effect of the HMOX1 rs2071749 SNP on gene expression in alveolar macrophages was investigated. Results We found a nominal association (p = 0.015) between one intronic HMOX1 SNP (rs2071749) and lung function decline but this did not survive correction for multiple comparisons. This SNP was in perfect linkage disequilibrium with rs3761439, located in the promoter of HMOX1. We tested rs3761439 and two other putatively functional polymorphisms (rs2071746 and the (GT)n polymorphism) in reporter gene assays but no significant effects on gene expression were found. There was also no effect of rs2071749 on HMOX1 gene expression in alveolar macrophages. Conclusions We found no association of the five HMOX1 tag SNPs with lung function decline and no evidence that the three promoter polymorphisms affected the regulation of the HMOX1 gene.