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• Exome sequencing of lung tissue conducted in SMC

  The data includes exome sequencing FASTQ files of 335 patients receiving immune checkpoint blockade therapy. The data only provides for WXS of tumor tissue.

  Dataset EGAD00001009101

• Epigenomic analysis of human dopaminergic neuron differentiation reveals LBX1, NHLH1 and NR2F1/2 as necessary for lineage specification

  Sample information: The 56 samples produced in this project come from the human iPSC line GM17602 (Coriell) where a tyrosine hydroxylase-T2A-mCherry reporter was inserted. A combination of epigenetic analysis (ATAC/ChIP) along transcriptomics.

  Dataset EGAD00001009288

• ctDNA whole exome genome sequencing dataset

  Dataset contains all available exome sequencing paired-end fastq files from our study "A generalizable machine learning framework for classifying DNA repair defects using ctDNA exomes"

  Dataset EGAD00001010069

• Dataset_for_linked_WES_and_WGS_data_from_EGAS00001004813 which belong also to EGAS00001005537 for germline controls of rare cancers

  WES/WGS sequencing data of 37 germline runs, which were uploaded to umbrella studies. The sequencing was always paired. The WGS sequencing was on HiSeq X Ten using the Illumina TruSeq DNA Nano Kit. The WES Sequencing was on HiSeq4000 with Agilent Sureselect V5+UTR.

  Dataset EGAD00001010046

• 47 urothelial cancer patients WES and 38 RNAseq

  We performed a global mutational landscape analysis using tumor samples from the 47 urothelial cancer patients included in MATCH-R or MOSCATO studies, with advanced metastatic disease and WES available (RNAseq is included for 38 patient samples).

  Dataset EGAD00001011063

• Single-cell RNA-Seq (Chromium Next GEM Single Cell 3' Reagent Kits v3.1 from 10X Genomics )

  Human data for transcriptome (scRNA-Seq) in CD34+ B cell precursors.

  Dataset EGAD00001010907

• MSC_busulfan_small_intestine_organoids

  This dataset represent the RNA-seq, which was done on untreated small intestinal organoids; small intestinal organoids treated with chemotherapeutic, busulfan; untreated small intestinal organoids co-cultured wth mesenchymak stromal/stem cells (MSCs; busulfan treated small intestinal organoids co-cultured with MSCs. The same set of samples was done for 3 different primary bone marrow MSC donors.

  Dataset EGAD00001011176

• DNA and RNAseq of serial biopsies from 75 DLBCL patients

  This data set includes serial biopsies from 75 patients with DLBCL. Tumour tissue was preserved either in FFPE or frozen. Each biopsy was sequenced with either whole genome or exome. A custom targeted sequencing data set is available to match most whole genome samples. RNAseq data were available for a subset of biopsies.

  Dataset EGAD00001011816

• WGS dataset for Unraveling mutagenic processes influencing the tumor mutational patterns of individuals with Constitutional Mismatch Repair Deficiency

  Molecular characterization of 41 tumors from 17 individuals with CMMRD to gain a better understandig of mutational processes driving subsequent tumor development. The molecular characterization includes the investigation of tumor mutational load and mutational signatures.

  Dataset EGAD00001015157

• Exome Atlas in HCC tumors

  The atlas provides a comprehensive exploration of genetic and transcriptomic landscapes within HCC, offering insights into key genomic alterations and gene expression patterns. The integration of exome sequencing and RNAseq data enhances our understanding of the molecular complexity underlying HCC, potentially paving the way for targeted therapeutic strategies and biomarker discovery in the context of hepatocellular carcinoma.

  Dataset EGAD00001015342

• STAMPEED: Whole Genome Association Analysis of Hematopoietic Cell Transplant (HCT) Outcomes

  This retrospective cohort study was designed to identify single nucleotide polymorphisms (SNPs) that are associated with complications after allogeneic hematopoietic cell transplantation (HCT). Validated discoveries provide information to improve risk assessment, counseling and treatment planning and to direct future mechanistic studies of the genes and pathways that influence outcomes, thereby providing insight and rationale for new targeted therapies. The study was conducted with the use of 3 different approaches. (1) We used GWAS discovery and replication analyses to identify SNPs variants associated with outcomes after HCT. (2) We tested SNP alleles in HLA-matched sibling donors and recipients to determine whether mismatching in the recipient is associated with graft-versus-host disease (GVHD) or the risk of recurrent malignancy after HCT. Such associations would suggest that the peptide encoded by the SNP allele functions as a minor histocompatibility antigen. (3) We performed in silico candidate SNP studies to determine the validity of previously published results showing associations with outcomes after HCT. The study population represents a large cohort from the Fred Hutchinson Cancer Research Center and consists of 4,471 recipients and 4,628 donors containing 4,258 recipient-donor pairs. Recipients suffered from a hematologic malignancy or myelodysplastic syndrome and were treated in a highly structured clinical research environment with comprehensive monitoring and systematic data recording. We used proportional hazards analyses to test for associations with acute and chronic GVHD, acute kidney injury, gram-negative bacteremia, invasive fungal disease, CMV infection and disease, recurrent malignancy, death not attributable to recurrent malignancy, and death after recurrent or progressive malignancy.

  Study phs001918

• Angelman, Rett, Prader-Willi Syndromes Consortium (ARP) Angelman Syndrome Natural History Protocol

  This study is a longitudinal multidisciplinary investigation on the natural history, morbidity and mortality of Angelman Syndrome (AS). We will collect detailed longitudinal data on a cohort of AS individuals to gain a better understanding of the disease progression, and to follow the natural history of the clinical features of this cohort including assessment of quality of life and longevity. The participants to be recruited for the study will include 1) patients who have a documented molecular diagnosis of AS and 2) patients with a clear clinical diagnosis of Angelman Syndrome as determined by the Principal Investigator (PI) and the Co-investigators in this study but who do not have a known molecular defect. One of the goals of the natural history study will be to characterize the phenotypic differences between patients with Class I deletions and those with Class II deletions, particularly with respect to the issue of autism. A blood sample may be collected on the participants in order to create a DNA repository, and in some cases, to establish cell lines if further material is required for molecular studies. Alternatively, DNA may be obtained by buccal mucosa swabs/brushing. In those AS patients with known deletions involving the 15q11-q13 regions, a blood sample will be collected to perform comparative genome hybridization (CGH) microarray studies to characterize the extent of the deletion. No drugs or treatments will be administered through this protocol. In rare instances, a skin biopsy to establish a fibroblast cell line may be requested (using separate consent).

  Study phs000576

• A Single Cell Transcriptomic Analysis of Human Neocortical Development

  Defining the number, proportion, or lineage of distinct cell types in the developing human brain is an important goal of modern brain research. We produced single cell transcriptomic profiles for 40,000 cells at mid-gestation to define deep expression profiles corresponding to all known major cell types at this developmental period and compare this with bulk tissue profiles. We identified multiple transcription factors (TFs) and co-factors expressed in specific cell types, including multiple new cell-type-specific relationships, providing an unprecedented resource for understanding human neocortical development and evolution. This includes the first single-cell characterization of human subplate neurons and subtypes of developing glutamatergic and GABAergic neurons. We also used these data to deconvolute single cell regulatory networks that connect regulatory elements and transcriptional drivers to single cell gene expression programs in the developing CNS. We characterized major developmental trajectories that tie cell cycle progression with early cell fate decisions during early neurogenesis. Remarkably, we found that differentiation occurs on a transcriptomic continuum, so that differentiating cells not only express the few key TFs that drive cell fates, but express broad, mixed cell-type transcriptomes prior to telophase. Finally, we mapped neuropsychiatric disease genes to specific cell types, implicating dysregulation of specific cell types in ASD, ID, and epilepsy, as the mechanistic underpinnings of several neurodevelopmental disorders. Together these results provide an extensive catalog of cell types in human neocortex and extend our understanding of early cortical development, human brain evolution and the cellular basis of neuropsychiatric disease.

  Study phs001836

• Somatic Genome Dynamics of Barrett's Esophagus Patients with Non-Cancer and Cancer Outcomes

  A case-control study was designed with 80 participants diagnosed with Barrett's Esophagus (BE) selected from a larger case-cohort study (Li et al., 2014, PMID: 24253313) within the Seattle Barrett's Esophagus Program (SBEP) at the Fred Hutchinson Cancer Research Center. The study included 40 cases with BE with non-cancer outcomes, "NCO", who did not progress to esophageal adenocarcinoma (EA), and 40 controls who progressed to an endoscopically detected, incident EA (cancer outcome, "CO"). For each patient, two timepoints were evaluated (T1 and T2). NCO were matched to CO based on age at T1 (T1=first endoscopy with sufficient sample availability), and time between T1 and T2 (T2 in CO=time of diagnosis of incident EA). In 10 NCO, a third time point (T3), a mean of 13.2 years after T1, was also sequenced. Mapped endoscopic biopsies, at 1/3 and 2/3 annotated distances from the gastroesophageal junction within the Barrett's segment, were sampled per patient at each timepoint. Each biopsy was purified to separate BE epithelium from stroma, and DNA was extracted from purified epithelium for 60X WGS and 2.5M SNP array; normal control blood (N=62) or normal gastric sample (N=18) were analyzed by 30X WGS and 2.5M SNP array. An additional seven normal gastric biopsy samples in seven patients with normal control blood were also sequenced at 60X as controls. All research participants contributing clinical data and esophageal samples to this study provided written informed consent, subject to oversight by the Fred Hutchinson Cancer Research Center IRB Committee D (Reg ID 5619).

  Study phs001912

• SLCO1B1 Variants and Methotrexate Clearance

  Methotrexate plasma concentration is related to its clinical effects. To identify the genetic basis of interindividual variability in methotrexate pharmacokinetics in children with newly diagnosed acute lymphoblastic leukemia (ALL), we performed a genome-wide analysis (GWAS) of 500,568 germline single-nucleotide polymorphisms (SNPs) in 434 children with ALL who received 3,014 courses of methotrexate at 2 to 5 g/m2. SNPs were validated in an independent cohort of 206 patients. Adjusting for age, race, sex, and methotrexate regimen, the most significant associations were with SNPs in the organic anion transporter polypeptide, SLCO1B1 (rs11045879 (P = 1.7 x 10-10) and rs4149081 (P = 1.7 x 10-9) (Trevino et al, PMID: 19901119). To test whether rare variants in SLCO1B1 could alter its function, we genotyped SLCO1B1 exons in a slightly larger group of 699 children with ALL who received methotrexate and identified 93 single nucleotide polymorphisms (SNPs). We found several common and rare non-synonymous (NS) SNPs associated with methotrexate clearance. NS SNPs predicted to be functionally damaging (common or rare) were more likely to be found among patients with the lowest adjusted methotrexate clearance (lowest 10%) than patients with high clearance (highest 10%). Four SLCO1B1 haplotypes were associated with reduced methotrexate clearance and we verified that these haplotypes have lower function with in vitro transport assays. We were able to quantitatively account for a third of the population variability in clearance of methotrexate with clinical and genetic covariates. This data set includes the dependent variable of methotrexate clearance and all of the SNP data available from arrays, sequencing, and genotyping.

  Study phs000426

• Investigation of the Causal Etiology in a Patient with T-B+NK+ Immunodeficiency

  We describe a male proband with normal B lymphocyte and natural killer (NK) cell numbers, but who had T lymphopenia beginning at 1 week of age. His peripheral blood contained very few T cell receptor excision circles (TREC), suggesting impaired thymic T cell development. He received an allogeneic hematopoietic stem cell marrow transplant, but despite engraftment, it did not fully correct the T lymphopenia. Sequencing excluded known immunodeficiency genes; however, whole exome sequencing revealed X-linked inheritance by the male proband of a missense mutation in MED14 (MED14V763A), a component of the mediator complex. Functional screening of the MED14V763A variant in zebrafish suggested that MED14 is essential for normal development, since morpholino (MO)-mediated loss of MED14 function attenuated T cell development, but it was rescued by ectopic expression of the wild type human MED14 but not by the MED14V763A variant. This defect in T cell repopulation is consistent with the incomplete T cell reconstitution observed upon transplantation of the proband with bone marrow from his healthy male sibling, who was found to have the same MED14V763A variant. However, the brother was normal, indicating that the altered MED14 could not by itself explain the disease. WES also revealed a mutation in the L1 cell adhesion molecule (L1CAMQ498H); however, introducing that mutation in vivo in mice did not disrupt T cell development. Consequently, the immunodeficiency in the patient is not fully elucidated. It is possible that MED14 contributes, but it is also possible that another gene is fully responsible for the disease.

  Study phs002990

• Common Variation in Candidate Genes in the Diabetes Prevention Program

  The Diabetes Prevention Program (DPP) was a multicenter controlled clinical trial examining the efficacy of an intensive lifestyle intervention or metformin to prevent or delay the development of diabetes in a population selected to be at high risk due to the presence of impaired glucose tolerance (IGT) and obesity. Development of diabetes, defined by 1997 American Diabetes Association (ADA) criteria, was the primary outcome while cardiovascular disease and its risk factors were important secondary outcomes. The pharmacological intervention was double blinded and placebo controlled. After randomization, participants had quarterly clinical evaluations and had, in addition, a fasting plasma glucose at semi-annual visits and a 75 gram oral glucose tolerance test at annual visits. Volunteers were recruited from populations known to be at particularly high risk for impaired glucose tolerance and type 2 diabetes including the following: persons with a family history of NIDDM, the elderly, overweight individuals, women with a history of diabetes during pregnancy ("gestational diabetes"), and minority populations including African Americans, Hispanic Americans, Asian and Pacific Island Americans, and Native Americans. The primary focus of the genetic investigations have been on candidate genes, including candidates derived from GWAS of diabetes, lipid and glycemia-related phenotypes. Please note more phenotype data for the DPPG cohort is available through the NIDDK Data Repository. Information on obtaining this phenotype data can be found by going to https://www.niddkrepository.org/studies/dppos/?query=DPP and https://www.niddkrepository.org/studies/dpp/?query=DPP. Data will need to be requested from both data sets. A linking file will be available to the NIDDK Data Repository.

  Study phs000681

• Strabismus, CCDD and other anomalies

  Strabismus is one of the most common ophthalmological diseases affecting our population. It has many detrimental effects for affected individuals, including functional visual loss from amblyopia, secondary psychosocial difficulties, and limited employment opportunities. Strabismus also imposes a significant economical burden on society from the cost of screening programs, surgical correction, and lost productivity. Congenital incomitant strabismus is a broad term that encompasses congenital ocular motility disorders with restricted movement in one or more directions of gaze, and includes various forms of Duane's retraction syndrome, horizontal gaze palsy, congenital fibrosis of extraocular muscles, and Moebius syndrome. Incomitant strabismus together with a group of related disorders such as congenital ptosis and congenital facial palsy have been collectively redefined as congenital cranial dysinnervation disorders (CCDDs). This redefinition stemmed from previous studies in the Engle lab showing that these disorders can be caused by mutations in genes encoding transcription factors critical to ocular cranial motor neuron development and by genes that encode proteins essential to the proper growth and guidance of developing axons. Thus, while these disorders account for only a small percent of strabismus, understanding their genetic etiology has led to our ability to provide genetic testing and counseling, and has provided the first insights into the molecular etiologies of strabismus. While the Engle lab has identified all seven CCDD genes published to date, our cohort still includes >100 familial CCDD pedigrees that are mutation-negative. We continue to utilize co-segregation analysis and whole exome or whole genome sequencing technologies to identify new disease genes in this mutation-negative cohort.

  Study phs000478

• Stand Up To Cancer East Coast Prostate Cancer Research Group

  Most prostate cancer deaths are caused by metastatic, castration resistant disease (mCRPC). To develop a precision medicine framework for mCRPC, we established a multi-institutional, international clinical sequencing infrastructure to enroll and carry out prospective whole exome and transcriptome sequencing of tumors from a cohort of mCRPC patients. We obtained high quality DNA and RNA sequence data from 150 bone or soft tissue biopsies. Central pathology revealed high-grade adenocarcinoma with only four cases (3.6%) showing neuroendocrine differentiation. Aberrations of AR, ETS genes, TP53 and PTEN were frequent (40-60% of cases), with TP53 and AR alterations being the most enriched in mCRPC compared to primary prostate cancer. We identified novel genomic alterations in PIK3CA/B (fusions and mutations); R-spondin, BRAF and RAF1 (fusions); APC (inactivating mutations); delta-catenin (missense mutations); and ZBTB16/PLZF (homozygous deletions). Aberrations of BRCA2, BRCA1 and ATM were observed at substantially higher frequencies (19.3% overall) than seen in primary prostate cancers, with 56% of these being exclusively somatic. Putative driver gene alterations were identified in nearly all patients, and over half also harbored driver gene fusions, homozygous deletions and/or amplifications. Moreover, 89% of patients harbored a clinically actionable aberration including 62.7% with aberrations in AR, 65% in other cancer-related genes, and 8% with actionable pathogenic germline alterations. Overall, integrative clinical sequencing analysis can be safely and efficiently performed in mCRPC, yields findings that may be actionable for enrolling patients in clinical trials of targeted therapies, and may inform the basis of individual clinical responses.

  Study phs000915

• Genetics of Mammographic Density in Ashkenazi Jews

  Mammographic density (MD) is a strong risk factor for breast cancer and is also a highly heritable trait with ~60-70% of the variance due to genetic factors, based on twin studies. MD is also higher in families with a strong history of breast cancer. Genome-wide association studies (GWAS), which focus on common genetic variants, have identified several single nucleotide polymorphisms (SNPs) associated with MD. However, these SNPs explain a very small fraction of the variance of MD, suggesting many other genes are involved. Thus, the vast majority of the heritability of mammographic density remains unexplained and may be explained, at least in part, by rare variants. Ashkenazi Jewish women are a founder population; founder populations frequently have alleles affecting phenotypes which may be unique and/or extremely rare in other populations. Prior reports have identified an association between higher mammographic density and Ashkenazi Jewish ancestry. Therefore, we developed a study of mammographic density in AJ women. We combined datasets from several different cohorts including (a) the California Pacific Medical Center Research Institute (b) the Athena Breast Health Cohort and (c) the Marin Women's study. In each study, we identified women who reported AJ ancestry (determined by self-report or by genetic analysis). We identified mammograms by linking the women to the San Francisco Mammography Registry. We retrieved digital mammographic results and used software to infer volumetric density and percent volumetric density for each woman. We then performed genome-wide genotyping of the samples using the Illumina MEGA array.

  Study phs001857

• Decoding Human Heart Morphogenesis through Single-cell Multi-modal Analyses

  The heart, which is the first organ to develop, is highly dependent on its form to function. However, how diverse cardiac cell types spatially coordinate to create complex morphological structures critical for heart function remains to be elucidated. Here, we show that integration of single cell RNA-sequencing with high-resolution multiplexed error-robust fluorescent in situ hybridization (MERFISH) not only resolves the identity of cardiac cell types developing the human heart but also provides a spatial mapping of individual cells that enables illumination of their organization into cellular communities forming distinct cardiac structures. We discovered that many of these cardiac cell types further specified into subpopulations exclusive to specific communities, supporting their specialization according to cellular ecosystem and anatomic region. In particular, ventricular cardiomyocyte subpopulations displayed an unexpected complex laminar organization across the ventricular wall and formed, with other cell subpopulations, several cellular communities. Interrogating cell-cell interactions within these communities revealed signaling pathways orchestrating the spatial organization of cardiac cell subpopulations during ventricular wall morphogenesis. In vivo conditional genetic mouse models and in vitro human pluripotent stem cell studies confirmed an intricate multicellular PLXN-SEMA crosstalk among specific ventricular cardiomyocyte, fibroblast and endothelial cell subpopulations that directs the compaction of the ventricular wall layers. Thus, these detailed findings into the cellular social interactions and specialization of cardiac cell types constructing and remodeling the human heart offer new insights into structural heart diseases as well as engineering complex multi-cellular tissues for human heart repair. Reprinted from Farah et al. (In press), with permission from Nature.

  Study phs002031

• Genetics of Mood Disorders: Aging and Emotion Regulation Brain Circuitry in Bipolar

  This single-site study is designed to investigate age-related changes in structure and function of a ventral prefrontal cortex (VPFC) neural system, that subserves emotion processing and regulation, during mid to later adulthood in individuals with bipolar disorder (BD), compared to healthy controls (HC). It is a 5-year study of age-related changes in mood, emotion regulation and related symptoms and behaviors using multimodality imaging measures [structural magnetic resonance imaging (MRI) of gray matter, diffusion tensor imaging (DTI) of white matter, and functional MRI measures of functional connectivity and of brain responses during implicit and explicit emotion regulation] comparing BD and HC groups ages 40-79 years, 50% female; a subgroup will be reassessed and rescanned after 2 years to study brain and associated behavioral changes over time. We will explore relationships between brain aging with risk factors implicated in progression. This will include genes, as well as adverse outcomes of progression such as suicide ideation and behavior. As there has been little study of effects of aging of the VPFC emotional circuitry in healthy individuals, findings could provide new insights into brain circuitry and emotional regulation in older adults. In addition to the importance of contributing to understanding BD, as BD is unique in having both elevated and depressive episodes, its study can provide a model for understanding progressive emotion dysregulation to both intervention and prevention that can be better targeted specifically for older individuals with BD. A de-identified blood sample will be sent to the Repository and Genomics Resource.

  Study phs001631

• Global Endometrial DNA Methylation Analysis Reveals Insights into mQTL Regulation and Associated Endometriosis Disease Risk and Endometrial Function

  Endometriosis is a common gynecological disorder affecting 11% of reproductive aged women and is a leading cause of pain and infertility. We investigated global DNA methylation (DNAm) profiles in endometrium associated with endometriosis, menstruation, and genetic variation. Endometrial samples were collected from 984 patients with confirmed endometriosis (n=637) and women without endometriosis (n=347). Patients were recruited through the University of California San Francisco, USA, University of Melbourne, Australia, Endometriosis CaRe Centre in Oxford, UK, and EXPPECT Centre, The University of Edinburgh, UK, using the World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonization Project (WERF EPHect) standardized protocols for tissue collection and processing, and participant characteristics and clinical annotation. DNA was extracted from samples and was use to generate DNAm data using the Illumina Infinium MethylationEPIC Beadchip and genotype data using the Axiom Precision Medicine Research array. Estimates from this study suggest that 15.4% of the variation in endometriosis is captured by DNAm. DNAm analysis identified significant differences in DNAm profiles and DNAm networks, associated with endometriosis, endometriosis sub-phenotypes, and menstrual cycle phases. Integration of DNAm and genetic data in a DNAm quantitative trait locus (mQTL) analysis identified 118,185 independent cis-mQTLs including 51 associated with risk of endometriosis highlighting target genes contributing to disease risk. This study identified novel factors affecting epigenetic regulation in endometrium associated with endometriosis risk and disease heterogeneity and provides an important data resource for reproductive medicine. Genotype data generated as part of this study are available on dbGaP and methylation data are available on GEO.

  Study phs003307

• Single Chromatin Fiber Profiling in the Human Brain

  We developed a human postmortem brain-applicable ‘Fiber-seq' protocol for genome-scale, PCR-free single molecule sequencing of on average 8-10kb long chromatin fibers, to map nucleosome positioning and nucleosome-depleted regions which include, for example, active promoters and enhancers. We generated two Fiber-seq reference sets, one from sorted non-neuronal NeuN- prefrontal cortex (PFC) nuclei from a 32 year old female donor, with total of 11,143,795 reads/fibers, and median of 30-fold genomic coverage. The other reference set was generated on sorted prefrontal NeuN+ neurons, from two 24 year old brain donors (1 female/1 male), with a combined total read/fiber count of 4,749,556 and median of 20-fold genomic coverage. Each of the peaks in the Fiber-seq libraries seq signal correlated with the ATAC peak levels in the neuronal and non-neuronal ATAC-seq libraries, respectively (promoters, clusters 1, 3; NeuN+, r = 0.574; NeuN-, r=0.683, PHowever, Fiber-seq detected 19,978 highly significant peaks which, while showing some non-significant/near-background ATAC-Seq alignments, lacked a corresponding site-specific enrichment in conventional short-read ATAC- and ChIP-seq datasets. However, 60% of these peaks were in repetitive DNA elements. Therefore, long read single chromatin fiber sequencing, which exceed the base pair length of conventional short-read libraries by two orders of magnitude, could capture many actively regulated repeat elements at the site of specific gene loci, that otherwise would remain unmappable by conventional ATAC-, and histone- ChiP-seq.

  Study phs003771

• Epigenetic Control of Topoisomerase 1 by MacroH2A1.1

  DNA transactions introduce torsional constraints that pose an inherent risk to genome integrity. While topoisomerase 1 (TOP1) activity is essential for removing DNA supercoiling, aberrant stabilization of TOP1:DNA cleavage complexes (TOP1ccs) can result in cytotoxic single-stranded DNA lesions (SSLs). What protects the genome from aberrant TOP1 activity remains unknown. Using a combination of CUT&RUN and TOP1 Covalent Adduct Detection (CAD) Seq in MDA-MB-231 breast cancer cells (American Type Culture Collection, ATCC), we identified chromatin context as an essential means to ensure TOP1cc resolution at TOP1 hot spots. Through its ability to bind poly(ADP-ribose) (PAR), a protein modification required for TOP1cc repair, the histone variant macroH2A1.1 establishes a TOP1-permissive chromatin environment, while the alternatively spliced macroH2A1.2 isoform is unable to bind PAR or protect from TOP1ccs. MacroH2A1 isoform-specific analyses were based on reconstitution of macroH2A1.1 knockout cells with wild-type or PAR binding-deficient FLAG-tagged macroH2A1.1 in human breast cancer cells. Mechanistically, we find that macroH2A1.1 facilitates the recruitment of the TOP1cc repair factor XRCC1 in response to both endogenous and drug-induced topological stress. Impaired macroH2A1.1 splicing, a frequent cancer feature, was predictive of increased sensitivity to TOP1 poisons in a pharmaco-genomic screen in breast cancer cells, and macroH2A1.1 inactivation mirrored this effect in breast and ovarian cancer cells. Consistent with this, low macroH2A1.1 expression correlated with improved survival in cancer patients treated with TOP1 inhibitors (TOP1i). We propose that macroH2A1 alternative splicing serves as an epigenetic modulator of TOP1-associated genome maintenance and a potential cancer vulnerability.

  Study phs003729