Search Results - EGA European Genome-phenome Archive

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).

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Improved Detection and Identification of Microsatellite Instability Features in Colorectal Cancer

In this study, we analyzed a series of colorectal cancers using a new sequencing technology that sequences more than 200 microsatellite regions in parallel. With this technology, we evaluated mono-, di- , tri- and tetranucleotide repeats to provide a broad spectrum of microsatellite instability (MSI) events. This deep sequencing technology provides greater than 2000X coverage and eliminates the need for PCR amplification. Because every read corresponds to a single DNA molecule, we eliminated artifacts introduced by PCR that obscured true MSI events. Also included in our analysis is a new method for detection of somatic copy number changes in 83 cancer genes, with which we can infer chromosomal instability (CIN) status.

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DNA Methylation Markers and Pancreatic Cancer Risk in 3 Cohort Studies (NHS, PHS, HPFS)

Pancreatic cancer is the 4th leading cause of cancer deaths in the US. Due to the lack of early symptoms, pancreatic cancer is difficult to identify at early stages and no screening is available for the general population. Identifying pancreatic cancer at earlier stages could significantly improve survival with increased opportunities for surgery. New high-dimensional arrays designed to measure DNA methylation levels at hundreds of thousands of CpG sites throughout the genome have opened opportunities to examine the role of DNA methylation in cancer risk using blood samples. Using this method, archived samples from prospective studies can be used to examine early changes in the DNA methylation levels in individuals who develop cancer months or years later, providing new opportunities to better understand biological mechanisms and, perhaps, identify biomarkers for early detection. Pancreatic cancer cases and matched controls were obtained from 3 large cohort studies, the Nurses' Health Study (NHS), the Physician's Health Study (PHS), and the Health Professionals Follow-up Study (HPFS), to measure DNA methylation in stored buffy coats using a nested case-control study design.

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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.

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PAK4 inhibition improves PD-1 blockade immunotherapy

Introduction with rationale and aims for study Immune checkpoint blockade therapies have significantly altered the current landscape of cancer treatment. However, this immunotherapy still fails more often than it succeeds. There are now evidences that the lack of tumour infiltration by immune cells is the main mechanism of primary resistance to PD‐1 blockade therapies for cancer. It has been postulated that cancer cell‐intrinsic mechanisms may actively exclude T cells from tumours, suggesting that the finding of actionable molecules that could be inhibited to increase T cell infiltration may synergize with checkpoint inhibitor immunotherapy. With the idea of finding potential drivers of immune exclusion, we performed RNA sequencing analysis of biopsies from melanoma patients and compared the transcriptomic differences of samples that where infiltrated with those that did not have immune infiltration. Methods RNAseq analysis of gene expressions on biopsies from melanoma patients treated with checkpoint blockade were analysed. We focused on the variable of "infiltration: yes or no,", e.g. tumors that were well infiltrated by immune cells with those that kept immune cells out. Sequencing revealed a list of genes whose expression differed between the infiltrated and noninfiltrated tumors. The kinase PAK4 stood out as a good candidate for inhibition treatment in the future as it was consistently enriched in the samples without immune infiltration. To test whether immunotherapy would work better if we deleted PAK4, we first knocked out PAK4, using CRISPR‐Cas9, in the ‐resistant melanoma cell line, B16. Then they injected the melanoma cells into mice and observed that PAK4 KO tumours now responded to PD‐1 blockade. In order to elucidate whether pharmacological inhibition of PAK4 could recapitulate the results observed in the B16 PAK4 KO tumours, we obtained the PAK4 inhibitor, KPT-9274, from Karyopharm Therapeutics. Indeed, inhibiting PAK4 in combination with anti‐PD‐1 immunotherapy significantly slowed the growth of the B16 melanomas more than either drug alone. Results and Conclusions Transcriptomic analysis of melanoma tumors that were well infiltrated by immune cells with those that kept immune cells out revealed a list of genes whose expression differed between the infiltrated and non-infiltrated tumours. The result suggests that p21 activated kinase 4 (PAK4) is enriched in non-responding tumour biopsies with low T cell and dendritic cell infiltration. In addition, PAK4 decreased WNT activity, a signalling pathway that has previously been involved in immune exclusion. In mouse models, genetic deletion of PAK4 increased T cell infiltration and reversed resistance to PD‐1 blockade in a CD8 T cell-dependent manner. Furthermore, combination of with the PAK4 inhibitor, KPT-9274, improved anti‐tumour responses compared to anti‐PD‐1 alone. Therefore, high PAK4 expression is correlated with low T cell and dendritic cell infiltration and lack of response to PD‐1 blockade, which could be reversed with PAK4 inhibition. The data establish a rationale for targeting this kinase with inhibitors in combination with immune checkpoint inhibitors for patients. Future work and data that we can anticipate for this study Oncogenic signalling pathways and specially the WNT signalling pathway, have been associated with lack of immune infiltration and resistance to PD‐1 blockade therapies. Here, we show that PAK4 overcome resistance to PD‐1 blockade while significantly decreases WNT signalling activity. Therefore, it constitutes the first potential druggable target that is able to reverse oncogenic driven immune cell exclusion. However, the fully mechanism whereby PAK4 sensitizes tumours to immunotherapy remains to be fully elucidated. It is necessary to address whether PAK4 inhibition overcomes resistance through WNT signalling inhibition or if other signalling pathways are involved in the observed phenotype.

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Genomic Characterization of Brain Metastases from Lung Cancer

Metastatic disease to the brain is associated with a poor prognosis. Our understanding of the genetic drivers of metastasis remain limited. Whole-exome sequencing was performed from brain metastases from lung adenocarcinoma to identify putative drivers of metastatic progression.

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Primary Prostate Tumor Tissue DNA Methylation Profiles

The study cohort includes 525 Caucasian and African American prostate cancer (PCa) patients who underwent radical prostatectomy (RP) as primary therapy for clinically localized adenocarcinoma of the prostate. These patients were previously enrolled in one of two population-based studies: 1) men 40-64 years of age, diagnosed between January 1993 and December 1996; and, 2) men 35-74 years of age, diagnosed between January 2002 and December 2005. Gleason grade and sum, diagnostic PSA, and pathological tumor stage were obtained from the SEER cancer registry. Formalin-fixed paraffin-embedded prostate tumor tissue blocks were obtained from RP specimens and used to make hematoxalin and eosin stained slides, which were reviewed by pathologists to confirm the presence/location of adenocarcinoma. For each patient two 1-mm tumor tissue cores from the dominant lesion that were enriched with >=75% tumor cells were taken for DNA purification. The RecoverAll Total Nucleic Acid Isolation Kit (Ambion/Applied Biosciences, Austin, TX) was used to extract DNA, which was then quantified (PicoGreen), aliquoted onto 96-well plates and shipped to Illumina for DNA methylation profiling using the Infinium® HumanMethylation450 BeadChip.

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Characterization of Clonal Evolution in Microsatellite Unstable Metastatic Cancers through Multi-Regional Tumor Sequencing

Whole exome sequencing was performed on blood and multiple tumor samples from six patients with known microsatellite unstable tumors. Subclones within each tumor site were identified and within each subclone, differing microsatellite instability was characterized.

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National Institutes of Health H3Africa African Collaborative Center for Microbiome and Genomics Research (ACCME)

The African Collaborative Center for Microbiome and Genomics Research is a multi-institutional collaborative research project. The objectives of the project are to collaborate and implement high impact integrative epidemiology and genomics research into discovery of biomarkers associated with cervical carcinogenesis. Specifically ACCME links and leverages existing funded research and program activities at the collaborating institutions to study the interaction between vaginal microbiome, host genetic factors and molecular variants of Human Papilloma Virus (HPV) to determine correlates of viral persistence in the causal pathway of cervical cancer, a major cause of preventable mortality in Nigeria and other parts of sub-Saharan Africa. This research offers several opportunities to advance understanding of cervical carcinogenesis, viral oncogenesis, new biomarker discovery and risk stratification by genotype in a cohort of African women. Sponsorship: This project is sponsored by the National Institutes of Health (NIH)

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Count Me In (CMI): The Angiosarcoma (ASC) Project (CMI-ASCproject)

Count Me In - The Angiosarcoma Project: A Patient-Partnered Research Initiative to Accelerate Research in a Rare Sarcoma The Angiosarcoma Project (ASCproject) is a research study that directly engages angiosarcoma patients online and empowers them to accelerate cancer research by sharing medical information and clinical samples. Angiosarcoma is an exceedingly rare soft tissue sarcoma with an incidence of ~300 newly diagnosed cases per year in the United States. This low incidence has impeded large-scale research efforts in this disease that are strongly needed to catalyze research and improve clinical outcomes. The Angiosarcoma Project, launched in March 2017, has demonstrated the feasibility of directly engaging geographically dispersed patients to democratize research and establish a large patient cohort to characterize the genomic and clinical landscape of a rare disease. Angiosarcoma patients living in the US or Canada can access the study and consent online through an online portal (ASCproject.org). Enrolled patients are mailed saliva and blood draw kits, which can be used to extract germline DNA and cell-free DNA (cfDNA), respectively. The study team contacts participants' healthcare institutions to obtain medical records and a portion of archived tumor samples. All received tumor samples are subjected to centralized histological re-review by an expert pathologist to confirm a diagnosis of angiosarcoma. Whole exome sequencing is performed on tumor DNA, germline DNA, and cfDNA; transcriptome sequencing is performed on tumor RNA. De-identified data, including linked genomic, clinical, and patient-reported data, are shared via public databases on a recurring pre-publication basis. Participants are regularly provided updates on the study.

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National Cancer Institute Clinical and Laboratory Analysis of Familial Cancer

The purpose of this study is to continue the analysis begun on 09C0079 which was focused on identification of the genetic mutation associated with a new gastric polyposis syndrome, Gastric Adenocarcinoma and Proximal Polyposis of the Stomach (GAPPS). GAPPS, first described in 2012, is an autosomal dominant gastric polyposis syndrome that confers a substantial risk for gastric adenocarcinoma. The GAPPS phenotype consists of a carpeting of greater than 100 fundic gland polyps (FGPs) in the oxyntic mucosa of the gastric body and fundus, with antral sparing with some FGPs displaying high-grade dysplasia. This is in contrast to sporadic FGPs that are benign, most often are not associated with high-grade dysplasia though low-grade dysplasia has been reported, and are fewer in number. Gastric FGPs have been found to be associated with Familial Adenomatous Polyposis (FAP) and attenuated FAP, which is an autosomal dominant condition associated with germ line mutations in APC which confers a phenotype consisting of multiple (>100) adenomatous polyps in the colon and rectum developing after the first decade of life. FGPs are reported to occur in 12-84% of patients with FAP, whereas sporadic FGPs are identified in ~5% of patients undergoing upper gastrointestinal endoscopy. Gastric adenocarcinoma arising from FGPs in individuals with FAP have been reported. Other manifestations of FAP and AFAP include polyps in the upper gastrointestinal tract, congenital hypertrophy of retinal pigment epithelium, osteomas and epidermoid cysts, supernumerary teeth, desmoid formation, and other malignancies such as thyroid, small bowel cancer, hepatoblastoma, and medulloblastoma. Thus far there are no reports in GAPPS of polyposis arising in the esophagus, gastric antrum, pylorus, small intestine, or colon.

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Extent and Significance of Bacterial DNA Integrations in the Human Cancer Genome

The integration of exogenous DNA into the human genome can cause somatic mutations associated with oncogenesis. For example, the insertion of HPV DNA into human chromosomes is the single most important event leading to tumorigenesis in cervical cancer. It is also now preventable with vaccines against HPV. In contrast to viral DNA integrations, the instances and repercussions of bacterial DNA integration into the somatic human genome are less clear. Yet bacterial DNA integrations (BDI) found to be associated with tumorigenesis could also be prevented using therapeutics like vaccines that limit exposure to the bacteria. Previous analysis of publicly available sequencing data from the Cancer Genome Atlas (TCGA) showed BDIs from Pseudomonas spp. rRNA into the 5'-UTR of four proto-oncogenes as well as in Ig (the immunoglobulin gene) of gastric cancer samples. The original samples from TCGA were not available to validate these findings. Therefore, a different cohort of gastric cancer patients was identified in order to establish the presence BDIs. Whole exome sequencing was completed on seven tumor samples and six adjacent gastric samples, as well as one intestinal metaplasia sample and one non-atrophic gastritis sample. Four of those samples were also investigated with transcriptomics and whole genome sequencing. Given that 15-20% of cancers worldwide are linked to infections, more work is needed to understand the role of infectious agents in oncogenesis and the mechanisms underlying that role.

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Genomic and Genetic Characterization of Prostate Tumors Treated with Neoadjuvant Intense Androgen Deprivation Therapy

The purpose of this study was to develop better ways of detecting prostate cancer before and after pre-operative treatment, and to test the feasibility of multi parametric magnetic resonance imaging (mpMRI) for the localization and detection of focal prostate cancer both before and after pre-operative treatment with ADT and enzalutamide. In this study, patients with intermediate and high risk prostate cancer received six months of neoadjuvant intense androgen deprivation therapy prior to radical prostatectomy. Biopsies were acquired prior to treatment. Tissue from biopsy and radical prostatectomy were subjected to sequencing and analysis for determination of features associated with response or resistance to treatment.

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Count Me In (CMI): The Metastatic Prostate Cancer (MPC) Project (CMI-MPCproject)

Count Me In - The Metastatic Prostate Cancer Project: A Patient-Driven Research Initiative to Accelerate Metastatic Prostate Cancer Research The Metastatic Prostate Cancer Project (MPCproject; http://mpcproject.org/) is a research study that empowers men with metastatic and advanced prostate cancer to partner directly with researchers by sharing their samples and clinical information, with the ultimate goal of accelerating scientific discoveries that have clinical impact. The MPCproject enables any man with metastatic or advanced prostate cancer in the US and Canada to participate in cutting-edge genomic and molecular research, regardless of where they live. Metastatic or advanced prostate cancer patients visit the project website and complete an online questionnaire of basic information about themselves and their cancer. Enrolled patients are mailed saliva and blood draw kits, which can be used to extract germline DNA and cell-free DNA (cfDNA), respectively. The study team contacts participants' healthcare institutions to obtain medical records and a portion of archived tumor samples. Whole exome sequencing is performed on tumor DNA, germline DNA, and cfDNA, and transcriptome sequencing is performed on tumor RNA. De-identified data, including linked genomic, clinical, and patient-reported data, are shared via public databases on a recurring pre-publication basis. Participants are regularly provided with updates on the study.

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Multimodal Genomic Features Predict Outcome of Immune Checkpoint Blockade in Non-small Cell Lung Cancer

This study evaluates integrated genomic models of response to immune checkpoint blockade for lung cancer patients. A computationally adjusted tumor mutation burden was combined with HLA class I genetic variation, mutational smoking signature and activating mutations in receptor tyrosine kinase genes to generate a prognostic classifier that outperforms tumor mutation burden.

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Hereditary Cancer Predisposition Syndromes and Uveal Melanoma

Uveal melanoma (UM) is a subtype of melanoma characterized by the strong contribution of genetic rather than environmental factors in the pathogenesis of the disease, making it an ideal model disease to study the genetic basis of cancer. The long-term goal of our laboratory is to determine the genes and mechanisms responsible for hereditary cancer predisposition associated with UM. BAP1 has been identified as a candidate gene with definitive association with predisposition to UM. However, pathogenic variants in BAP1 are detected in only a small subset of UM patients even those with strong personal and family history of cancer suggesting the existence of other candidate genes. The goal of this project is to identify novel candidate genes contributing to hereditary predisposition to UM in patients with no detectable germline pathogenic variant in BAP1.

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Genomic Characterization CS-MATCH-0007 Arm W

The CS-MATCH-0007 protocol is part of a collaboration between the Center for Cancer Genomics (CCG) and the Division of Cancer Treatment and Diagnosis (DCTD) to perform whole-exome sequencing and RNA sequencing using pre-and post-treatment tumor biopsy specimens from patients enrolled on a treatment arm of the NCI-MATCH Clinical Trial (EAY131). The goal of this study is to identify the molecular basis for response and resistance to targeted therapies that are matched to specific genomic alterations found in their cancers. Arm W is one of the treatment sub-protocols within the NCI-MATCH Clinical Trial (EAY131) where patients with FGFR fusions, mutations, amplifications are treated with AZD4547. This subprotocol is one of the treatment arms included in the CS-MATCH-0007 protocol and will provide specimens for the program including tumor tissue and whole blood.

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Women's Health Study Accelerometry Dataset

Background The Women's Health Study (WHS) was a randomized trial testing low-dose aspirin and vitamin E for preventing cancer and CVD among 39,876 women aged ≥45 years throughout the US from 1992-2004. When the trial ended as planned, women who were willing to participate continued in an observational follow-up study. Participants in Accelerometer Study From 2011-2015, an ancillary study collected data on physical activity and sedentary behavior using accelerometers. Women were mailed a triaxial accelerometer (ActiGraph GT3X+, ActiGraph Corp) with a wear log, and asked to wear this on their hip for seven consecutive days, removing it only during sleep and water-based activities. Further details have previously been published (PMID: 30666321). A total of 17,708 women wore and returned their devices, and data were downloaded from the devices of 17,466 women; no data were available from the other 242 (device failure). By convention, a "valid day" of wear has data on at least 10 hours (PMID: 22698174). Among these 17,466 women, 17,062 had at least one valid day of wear. The data are provided for all 17,062 women. Additionally, "compliant wear" is conventionally defined for participants wearing the device for at least 10 hours, on at least 4 days (PMID: 22698174). Of the 17,062 women, 16,741 had compliant wear (PMID: 29109088). Self-reported Physical Activity and Sedentary Behavior After we received the accelerometer from a WHS participant, she was sent a questionnaire asking her to report the time she spent in different physical activities during the week that the accelerometer was worn (see questionnaire below). A total of 15,514 women (91% of participants in the Accelerometer Study) returned their physical activity questionnaires. In addition, beginning in October 2012, we included questions on sedentary behavior; a total of 9,430 women returned questionnaires that included questions on both physical activity and sedentary behavior.

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MP2PRT: Identification of Genetic Changes Associated with Relapse and/or Adaptive Resistance in Patients Registered as Favorable Histology Wilms Tumor on AREN03B2

The Molecular Profiling to Predict Response to Treatment (MP2PRT) program is part of the NCI's Cancer Moonshot Initiative. The aim of this program is the retrospective characterization and analysis of biospecimens collected from completed NCI-sponsored trials of the National Clinical Trials Network and the NCI Community Oncology Research Program. This study, titled "Identification of Genetic Changes Associated with Relapse and/or Adaptive Resistance in Patients Registered as Favorable Histology Wilms Tumor on AREN03B2", performs genomic characterization (WGS 30X, Total RNAseq, miRNAseq) on a discovery set of 70 trio cases (normal tissue, tumor tissue at time of diagnosis, tumor tissue at time of relapse) from patients who relapsed with Favorable Histology Wilms Tumor. Prioritized findings from the discovery set will be validated using Targeted Sequencing in an independent validation set of 47 relapse samples.

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Cellular Origins and Genetic Landscape of Cutaneous GD T Cell Lymphoma

Cutaneous gamma-delta T cell lymphomas are a rare and aggressive subtype of cutaneous lymphoma. In the present study, we analyzed these cancers by DNA and RNA sequencing in order to illuminate the genetic landscape for this rare disease. We obtained tumor samples from multiple institutions, including Northwestern University (Chicago, IL), University of Chicago (Chicago, IL), University of Virginia (Charlottesville, VA), and Massachusetts General Hospital (Boston, MA).

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Kidney Two-Hit Mapping

Germ-line genetic variants identified thus far generally account for only part of the genetic risk predicted for most cancers. A component of the remaining risk may be explained by functionally consequent genetic variants that are individually very rare (or private to that individual's family). While their identification may be highly informative for cancer etiology and biological knowledge, strategies that allow for agnostic (genome-wide) identification of such genes are not straight forward. This is particularly true for rare cancers where sufficient numbers of patients may simply not be available for appropriate statistically powered studies. In this project we have explored a study design based around the concept of "two-hit mapping" using the co-occurrence of germ-line and somatic mutations in the same gene to assist in the identification of susceptibility genes. The dataset includes 54 kidney cancer patients selected for enrichment of genetic disease, that is patients with: early age of onset and/or family history and/or bilateral disease. Germ-line and somatic (kidney cancer) tumor sequencing was carried out. These data may improve our understanding of kidney cancer.

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Genomic Characterization CS-MATCH-0007 Arm Z1A

The CS-MATCH-0007 protocol is part of a collaboration between the Center for Cancer Genomics (CCG) and the Division of Cancer Treatment and Diagnosis (DCTD) to perform whole-exome sequencing and RNA sequencing using pre-and post-treatment tumor biopsy specimens from patients enrolled on a treatment arm of the NCI-MATCH Clinical Trial (EAY131). The goal of this study is to identify the molecular basis for response and resistance to targeted therapies that are matched to specific genomic alterations found in their cancers. Arm Z1A is one of the treatment sub-protocols within the NCI-MATCH Clinical Trial (EAY131) where patients with NRAS mutations are treated with Binimetinib. This subprotocol is one of the treatment arms included in the CS-MATCH-0007 protocol and will provide specimens for the program including DNA from tumor tissue and whole blood.

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Large Cancer Fingerprint Screening for Detection of Minimal Residual Disease.

We describe an approach for large cancer fingerprint screening and its application to cell-free DNA from patients with cancer. Our approach involves tracking somatic mutations identified from patients' tumor biopsies, in the cell-free DNA from a blood draw.

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Genomic Landscape of Human Skin at a Single-Cell Resolution

Every cell in the human body has a unique set of somatic mutations, yet it remains difficult to comprehensively genotype an individual cell. Here, we developed solutions to overcome this obstacle in the context of normal human skin, thus offering the first glimpse into the genomic landscapes of melanocytes at single-cell resolution. We comprehensively genotyped 133 melanocytes from 19 sites across 6 donors. As expected, sun-shielded melanocytes had fewer mutations than sun-exposed melanocytes. However, within sun-exposed sites, melanocytes on chronically sun-exposed skin (e.g. the face) displayed a lower mutation burden than melanocytes on intermittently sun-exposed skin (e.g. the back). Melanocytes from donors with a history of skin cancer had higher mutation burdens than melanocytes from donors without skin cancer, implying that the mutation burden of normal skin can be harnessed to measure cumulative sun damage and skin cancer risk. Moreover, melanocytes from healthy skin commonly harbor pathogenic mutations, likely explaining the origins of the melanomas that arise in the absence of a pre-existing nevus. Phylogenetic analyses identified groups of related melanocytes, suggesting that melanocytes spread throughout skin as fields of clonally related cells, invisible to the naked eye. Overall, our study offers an unprecedented view into the genomic landscapes of individual melanocytes, revealing key insights into the causes and origins of melanoma.

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University of Texas PDX Development and Trial Center Grant

The goal for the University Texas PDX Development and Trial Center (UTPDTC) is to optimize personalized biomarker-based cancer therapy and identify effective targeted drugs based on the molecular characteristics of each tumor. Our short-term goals are to establish a biobank of clinically, and molecularly-annotated Patient-Derived Xenografts (PDXs) and to use PDXs as a platform for preclinical drug development and biomarker discovery. The primary goal for UTPDTC investigators will be to develop PDX trial strategies for preclinical testing of single agents and drug combinations. These models will allow the determination of the optimal treatments (single drugs or combinations) that should be tested in clinical trials in increasingly individualized, molecularly defined subsets of tumors. The goal of the Patient-Derived Xenograft Core is to provide high-quality clinically relevant and molecularly annotated PDX models for the research projects proposed in the University of Texas PDX Development and Trial Center (UTPDTC) grant application and to the research activity of the NCI PDX Development and Trial Centers Research Network (PDXNet) by leveraging PDX resources at our institutions and developing new PDX models from human cancer specimens using rigorous quality standards so that the models can be used to guide clinical trial development. The PDX models developed and/or characterized by the PDX Core will be available to other cancer researchers through the PDXNet and NCI Patient-Derived Models Repository (PDMR).

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