14666 results for "PLOS+ONE+Pennsylvania+German+ACS+language+code+pdc+open+access+study"

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• Analysis of mutational and proteomic heterogeneity of gastric cancer to monitor post-treatment tumor burden using circulating tumor DNA

  It remains unclear whether complete spectrum of tumor heterogeneity is reflected in circulating tumor DNA (ctDNA). Here, we performed multi-regional target sequencing of primary tumors from 10 patients who underwent surgical resection for gastric cancer. A total of 126 non-synonymous mutations were identified from 30 samples from 10 tumors. Of these, 16 (12.7%) were likely mutations that occurred early in tumor development (i.e., present in all three regions) and were designated founder mutations. Among those validated with highly sensitive digital PCR (dPCR), 93% of non-founder mutations were found in all three regions. Variant allele frequencies (VAFs) of founder mutations were significantly higher than those of non-founder mutations. Phylogenetic analysis demonstrated that five of eight tumors (62.5%, excluding two hypermutator) had at least one identifiable truncal/founder mutation. These findings led us to prioritize founder mutations for ctDNA detection with individually-designed primer/probe sets for dPCR. Marked proteomic diversity was present across the tumor regions both within and between patients independent of mutational status. In preoperative plasma, the average ctDNA VAF of founder mutations was significantly higher than that of non-founder mutations (p = 0.039). Our present data demonstrated that high VAF mutations in the tumor likely represent founder or truncal mutations. However, mutation patterns alone appear insufficient to predict protein heterogeneity. These results suggest that, in practice, mutations having high VAF identified without multi-regional sequencing may be useful for ctDNA monitoring but are inadequate to fully predict proteomic heterogeneity of the tumor.

  Study JGAS000231

• Gene expression of human Th17 cells before and after activation

  Although gene expression of human Th17 clones has been studies, to date, molecular mechanisms for human Th17 development remain unclear. We have analyzed gene expression of human Th17 cells before and after activation. Th17-cell clones from peripheral blood CD4 T cells cultured with LPS-stimulated dendritic cells derived from monocytes stimulated by TNF were established by a limited dilution method. One of the Th17 clones was proliferated significantly, and high percentages (>70%) of Th17 cells in the cultured cells were maintained by addition of monocytes, IL-1b, and IL-15. CD161+CXCR3- cells (CD161+Th17) in the cultures were sorted and purified up to approximately 97% of IL-17-producing cells after treatment with PMA/ionomycin. Furthermore, these cells were treated with TCR-stimuli, IL-1b, and IL-23 for 2 days, and IL-17-producing Th17 cells (active-Th17) detected by IL-17-catch-up antibodies were sorted. Total RNA sampled from 1x 106 CD161+Th17, active-Th17, na?ve CD4 T cells, or CXCR3+ Th1 cells from combined CD4 T and dendritic cell cultures was used for SAGE. SAGE was performed by using SOLID TM SAGETM kit with barcoding adaptor molecules (Applied Biosystems). DNA sequence was analyzed by using AB5500 Genetic Analyzer (Applied Biosystems), and gene expression was analyzed by using SOLID? SAGETM software (Applied Biosystems). Our data shows high levels of IL-17A-mRNA expression by active-Th17; however, but only slight expression by CD161+Th17. Therefore, the data could provide alteration of gene expression by Th17 cells before and after stimulation.

  Study JGAS000005

• Identification of driver oncogenes in scirrhous-type gastric cancer cell lines

  Scirrhous type gastric cancer (SGC) is one of the most intractable cancer subtypes in human, and its therapeutic targets have been rarely identified to date. Exploration of somatic mutations in the SGC genome with the next generation sequencers has been hampered by low tumor contents by the markedly increased fibrous tissues. Thus, SGC cell lines may be useful resources to search for novel oncogenes in. Here we have conducted whole exome sequencing and RNA sequencing on two SGC cell lines, OCUM-8 and OCUM-9. Interestingly, most of the mutations thus identified have not been reported. In OCUM-8 cells, a novel CD44-IGF1R fusion gene is discovered, the protein product of which ligates the amino-terminus of CD44 to the transmembrane and the tyrosine-kinase domains of IGF1R. Further, both of CD44 and IGF1R are markedly amplified in the OCUM-8 genome and abundantly expressed. CD44-IGF1R has a transforming ability, and the suppression of its kinase activity leads to rapid cell death of OCUM-8. On the other hand, OCUM-9 seems to possess multiple oncogenic events in its genome. The MET gene is highly amplified, and the treatment of OCUM-9 with crizotinib, a MET inhibitor, results in cell death. Further, a novel BORCS5-ETV6 fusion gene is identified in the OCUM-9 genome. BORCS5-ETV6 possesses oncogenic activity, and suppression of its message partially inhibits cell growth. Prevalence of these novel fusion genes among SGC awaits further investigation, but we validate the significance of cell lines as appropriate reagents for detailed genomic analyses of SGC.

  Study JGAS000179

• WES analysis of a mixed cohort of pituitary tumors

  BACKGROUND: Sporadic pituitary adenomas are the second most common primary brain tumor, but their genetics remains incompletely understood. We performed deep DNA sequencing of 42 pituitary macroadenomas, including hormonally active and atypical adenomas. METHODS: Pituitary adenomas representative of a spectrum of histopathologic subtypes, primary and recurrent tumors, and MIB-1 proliferative indices were profiled. Whole-exome sequencing was performed on tumors and paired blood followed by analysis of somatic copy number alteration and mutation. RESULTS: On the whole, the tumors harbored a low rate of mutations, similar to other benign brain tumors. However, almost one-third (29%) exhibited somatic copy-number alterations across large fractions of the genome (up to 99%). Despite such widespread genomic disruption, these tumors had few focal events, which is atypical among highly-disrupted cancers. The other 71% of tumors formed a distinct molecular class, with somatic copy-number alterations involving less than 6% of the genome. Among the highly-disrupted group, 92% were functional or atypical null-cell adenomas, whereas 87% of the less-disrupted group were clinically non-functional adenomas. The only significantly recurrent events were arm-level losses of chromosomes 1, 2, 11, and 18. No significantly recurrent mutations or insertion/deletion events were identified, suggesting no genes are altered by exomic mutations in >15% of pituitary tumors. CONCLUSIONS: Genomic characterization of a large series of sporadic pituitary adenomas reveals two classes of tumor, based on genomic disruption from arm-level copy-number alterations, which associate with hormonal and histologic subtypes.

  Study EGAS00001001714

• Microsatellite data show recent demographic expansions in sedentary but not in nomadic human populations in Africa and Eurasia.

  The transition from hunting and gathering to plant and animal domestication was one of the most important cultural and technological revolutions in human history. According to archeologists and paleoanthropologists, this transition triggered major demographic expansions. However, few genetic studies have found traces of Neolithic expansions in the current repartition of genetic polymorphism, pointing rather toward Paleolithic expansions. Here, we used microsatellite autosomal data to investigate the past demographic history of 87 African and Eurasian human populations with contrasted lifestyles (nomadic hunter-gatherers, semi-nomadic herders and sedentary farmers). Likely due to the combination of a higher mutation rate and the possibility to analyze several loci as independent replicates of the coalescent process, the analysis of microsatellite data allowed us to infer more recent expansions than previous genetic studies, potentially resulting from the Neolithic transition. Despite the variability in their location and environment, we found consistent expansions for all sedentary farmers, while we inferred constant population sizes for all hunter-gatherers and most herders, which could result from constraints linked to a nomadic or semi-nomadic lifestyle and/or competition for land between herders and farmers. As an exception, we inferred expansions for Central Asian herders. This might be linked with the arid environment of this area, which may have been more favorable to nomadic herders than to sedentary farmers. Alternatively, current Central Asian herders may descent from populations who have first experienced a transition from hunter-gathering to sedentary agropastoralism, and then a second transition to nomadic herding.

  Study EGAS00001000652

• Exome sequencing of uterine leiomyosarcomas

  Uterine leiomyosarcomas (ULMSs) are aggressive smooth muscle tumors associated with poor clinical outcome. Despite previous cytogenetic and molecular studies, their molecular background has remained elusive. To examine somatic variation in ULMS, we performed exome sequencing on 19 tumors. Altogether 43 genes were mutated in at least two ULMSs. Most frequently mutated genes included tumor protein P53 (TP53; 6/19; 33%), alpha thalassemia/mental retardation syndrome X-linked (ATRX; 5/19; 26%), and mediator complex subunit 12 (MED12; 4/19; 21%). Unlike ATRX mutations, both TP53 and MED12 alterations have repeatedly been associated with ULMSs. All the observed ATRX alterations were either nonsense or frameshift mutations. ATRX protein levels were reliably analyzed by immunohistochemistry in altogether 44 ULMSs, and the majority of tumors (23/44; 52%) showed clearly reduced expression. Loss of ATRX expression has been associated with alternative lengthening of telomeres (ALT), and thus the telomere length was analyzed with telomere-specific fluorescence in situ hybridization. The ALT phenotype was confirmed in all ULMSs showing diminished ATRX expression. Exome data also revealed one nonsense mutation in death-domain associated protein (DAXX), another gene previously associated with ALT, and the tumor showed ALT positivity. Aberrant expression of both TP53 and ATRX were associated with poor overall survival. In conclusion, exome sequencing revealed that TP53, ATRX, and MED12 are frequently mutated in ULMSs. ALT phenotype was commonly seen in tumors, indicating that ATR inhibitors, which were recently suggested as possible new drugs for ATRX-deficient tumors, could provide a potential novel therapeutic option for ULMS.

  Study EGAS00001001612

• Recurrent epimutations activate gene body promoters in primary glioblastoma

  Aberrant DNA hypomethylation may play an important role in the growth rate of glioblastoma (GBM), but the functional impact on transcription remains poorly understood. We assayed the GBM methylome with MeDIP-seq and MRE-seq, adjusting for copy number differences, in a small set of non-glioma CpG island methylator phenotype (non-G-CIMP) primary tumors. Recurrent hypomethylated loci were enriched within a region of chromosome 5p15 that is specified as a cancer amplicon and also encompasses TERT, encoding telomerase reverse transcriptase, which plays a critical role in tumorigenesis. Overall, 76 gene body promoters were recurrently hypomethylated, including TERT and the oncogenes GLI3 and TP73. Recurring hypomethylation also affected previously unannotated alternative promoters, and luciferase reporter assays for three of four of these promoters confirmed strong promoter activity in GBM cells. Histone H3 lysine 4 trimethylation (H3K4me3) ChIP-seq on tissue from the GBMs uncovered peaks that coincide precisely with tumor-specific decrease of DNA methylation at 200 loci, 133 of which are in gene bodies. Detailed investigation of TP73 and TERT gene body hypomethylation demonstrated increased expression of corresponding alternate transcripts, which in TP73 encodes a truncated p73 protein with oncogenic function and in TERT encodes a putative reverse transcriptase-null protein. Our findings suggest that recurring gene body promoter hypomethylation events, along with histone H3K4 trimethylation, alter the transcriptional landscape of GBM through the activation of a limited number of normally silenced promoters within gene bodies, in at least one case leading to expression of an oncogenic protein.

  Study EGAS00001000685

• RB Loss in Resistant EGFR Mutant Lung Adenocarcinomas that Transform to Small Cell Lung Cancer

  Tyrosine kinase inhibitors (TKIs) are effective treatments for non-small cell lung cancers (NSCLCs) with epidermal growth factor receptor (EGFR) mutations. However, they do not lead to cures, and, on average, relapse occurs typically occurs afterafter an average of one year of continuous treatment. In a subset of patients, aA fundamental histological transformation from NSCLC to small cell lung cancer (SCLC) is observed in a subset of the resistant cancers, but the molecular changes associated with this transformation remain unknown. Analysis of a cohort of tumor samples and cell lines derived from resistant EGFR mutant patients with SCLC transformation revealed that RB is lost in 100% of these SCLC transformed cases, but rarely in those that remain NSCLC. Global changes in gene expression, including increased neuroendocrine marker expression and absence of EGFR expression, are observed in resistant EGFR mutant cancers that transformed to SCLC. Consistent Further, with their similarities to classical SCLC at the genetic and gene expression levelincreased neuroendocrine marker and decreased EGFR expression as well as greater sensitivity to BCL2 family inhibition are observed in resistant SCLC transformed cancers compared to resistant NSCLCs. , cell lines derived from resistant EGFR mutant SCLC biopsies are substantially more sensitive to Bcl-2 family inhibition with ABT-263 compared to those derived from resistant EGFR mutant NSCLCs. Together, these findings suggest that despite developing initially as EGFR mutant adenocarcinomas, this subset of resistant cancers ultimately adopt many of the molecular and phenotypic characteristics of classical SCLC.

  Study EGAS00001001102

• Confirmation of a founder effect in a Northern European population (FRL) of a new beta-globin variant: HBB:c.23_26dup (codons 8/9 (+AGAA))

  Beta-thalassemia is a genetic disease caused by a defect in the production of the beta-like globin chain. More than 200 known different variants can lead to the disease and are mainly found in populations that have been exposed to malaria parasites. We recently described a duplication of 4 nucleotides in the first exon of beta-globin gene in several families of patients living in Nord-Pas-de-Calais (France). Using the genotypes at 12 microsatellite markers surrounding the beta-globin gene of four unrelated variant carriers plus an additional one recently discovered, we found that they shared a common haplotype indicating a founder effect that was estimated to have taken place 225 years ago (9 generations). In order to determine whether this variant arose in this region of Northern-Europe or was introduced by migrants from regions of the world where thalassemia is endemic, we genotyped the first 4 unrelated variant carriers and 32 controls from Nord-Pas-de-Calais for 97 European ancestry informative markers (EAIMs). Using these EAIMs and comparing with population reference panels, we demonstrated that the variant carriers were very similar to the controls and were closer to North European populations than to South European or Middle-East populations. Rare beta-thalassemia variants have already been described in patients sampled in non-endemic regions but it is the first proof of a founder effect in Northern Europe. The new genetic panel FRL is under registration in EGA.

  Study EGAS00001000980

• Somatic mutations predict an aggressive phenotype in meningioma but do not drive grade progression

  A subset of meningiomas progress in histopathological grade and drivers of progression are poorly understood. We aimed to identify somatic mutations and copy number alterations (CNAs) associated with grade progression in a unique matched tumour dataset. Utilising a prospective database, we identified 10 patients with meningiomas that had undergone grade progression and for whom matched pre- and post-progression tissue (n=50 samples) was available for targeted next-generation sequencing. Mutations in NF2 were identified in 4/10 patients, 94% were non-skull base tumours. In one patient, three different NF2 mutations were identified in four tumours. NF2 mutated tumours showed large scale CNAs, with highly recurrent losses in 1p, 10, 22q, and frequent CNAs on chromosomes 2, 3 and 4. There was a correlation between grade and CNAs in a subset of patients. In two patients with sphenoid wing Grade III tumours without detected NF2 mutations, a STAT6-NAB2 inversion was identified. Two patients with tumours without detected NF2 mutations showed a combination of loss and high gain on chromosome 17q. Mutations in SETD2, TP53, TERT promoter and NF2 were not uniform across recurrent tumours and did not correspond with grade progression. Meningiomas that progress in grade generally have a mutational profile already detectable in the pre-progressed tumour, suggesting an aggressive phenotype . CNA profiling shows frequent alterations in NF2 mutated tumours compared to non NF2 mutated tumours and the pattern of CNAs may be associated with grade progression in a subset of cases.

  Study EGAS00001006585

• Genomic consequences of aberrant DNA repair mechanisms stratify ovarian cancer histotypes

  Aberrant DNA repair processes are a hallmark of human tumours. How these deficiencies variously impact the genomes of ovarian cancer between and within histotypes remains unknown. We studied the whole genome pointmutation and structural variation patterns of 133 tumours (59 high grade serous (HGSC), 35 clear cell (CCOC), 29 endometrioid (ENOC), and 10 adult granulosa cell tumours (GCT)) as a substrate for class discovery in ovarian cancer. Ab-initio clustering of integrated point mutation and structural variation signatures revealed seven novel subgroups, comprising between and within histotype stratification. Prevalence of fold-back inversions (FBI) co-localised with high level amplification events divided HGSC into two prognostically significant subgroups. This finding was recapitulated in two additional independent cohorts (total n=576 cases), and transcended gene based mutation status and gene expression as prognostically relevant features of HGSC. CCOC were divided into one group harbouring a signature reflective of active genome editing via APOBEC enzymes (26%) and a complementary group with an age-relatedmutational signature. ENOC were divided intomicrosatellite instable (MSI) cases (28%) with a distinctmismatch repairmutation signature and an outlying mutation rate, with the remainder of cases distributed amongst the remaining six groups. We suggest the FBI, MSI, and APOBEC groups represent biologic strata that could direct treatment strategies. Taken together, our work establishes the efficacy of the somatic genome as a biomarker to stratify ovarian cancers, simultaneously identifying patients that may benefit from emerging therapeutics and distinct subgroups within classic ovarian cancer histotypes.

  Study EGAS00001002390

• Circumventing intratumoral heterogeneity to identify potential therapeutic targets in hepatocellular carcinoma. Details please contact lifuqiang@genomics and zhaoxin@genomics.cn.

  Background and aims: Intratumoral heterogeneity (ITH) challenges identifying mutations with target therapy potential whereas circulating cell-free DNAs (cfDNAs) could reflect nearly the entire mutation spectrum in given tumors. We investigated how to minimize the limit of ITH for profiling hepatocellular carcinoma (HCC).Methods: Thirty-two multi-regional HCC samples from five patients were subjected to whole exome sequencing (WES) and targeted deep sequencing (TDS). ITH extent was measured by the average percentage of non-ubiquitous mutations (present in parts of tumor regions). Matched cfDNAs were also analyzed by WES and TDS. Profiling efficiencies of single tumor specimen and cfDNA were compared and the one better depicted mutational landscape was selected to screen therapeutic targets.Results: We found variable extents of ITH in HCCs and observed branched and parallel evolution patterns. ITH level decreased at higher sequencing depth of TDS than that measured by WES (28.1% vs 34.9%, P < 0.01) but it remained unchanged upon additional samples analyzed. TDS of single tumor specimen detected an average of 70% the total mutations in HCC. Although more mutations were detected in cfDNA under TDS than WES, an average of 47.2% total HCC mutations uncovered by cfDNA suggested tissue outperform cfDNA and the latter may serve as alternative in profiling HCC genome. Consequently, TDS of single tumor tissue in 66 patients and cfDNAs in four unresectable HCCs identified 38.6% (26/66 and 1/4) patients bearing therapeutic targets.Conclusions: TDS of single tumor specimen could largely circumvent ITH to uncover mutations indicative of target therapy in HCC.

  Study EGAS00001002207

• The genomic landscape of pediatric acute lymphoblastic leukemia

  Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer and arises from B- or T-lineage lymphocyte precursors. ALL comprises dozens of subtypes, and genomic analyses have largely been performed within these subtypes. Here we analyze pediatric ALL genomes across all subtypes, including 768 whole genomes, 1,729 exomes, and 1,889 transcriptomes in 2,754 patients. Most ALL subtypes harbor 4 or more driver alterations per sample, similar to adult cancers, despite low mutation burdens. Hyperdiploid B-ALL copy gains are likely acquired early and synchronously, with copy gains occurring before ultraviolet-induced mutations. By contrast, ultraviolet-induced mutations precede copy gains in iAMP21 B-ALL. Overall, we identified 378 putative ALL driver genes. Most driver alterations vary in prevalence across ALL subtypes, with B-ALL enriched for Ras and B-lineage-related alterations, and T-ALL enriched for PI3K, JAK, and cell cycle alterations. Most B-ALL (54.3%) and T-ALL (51.2%) samples bear at least one rare driver gene alteration (present in less than 2% of samples), including 30 putative novel cancer driver genes associated with ubiquitination, SUMOylation, non-coding, and other functions. Known or novel alterations associated with poor outcomes in specific subtypes include TBL1XR1 alterations in ETV6-RUNX1 patients, CREBBP in Ph-like-CRLF2, SETD2 in hyperdiploid, and PTEN in TAL1 patients. Intriguingly, DUX4 and KMT2A subtypes separate into CEBPA/FLT3- or NFATC4-expressing subgroups with potential clinical implications. Together, these results deepen understanding of ALL etiology and outcomes, and facilitate ALL model development.

  Study EGAS00001005250

• Structure and evolution of double minutes in diagnosis and relapse brain tumors

  Double minute chromosomes are extrachromosomal circular DNA fragments frequently found in brain tumors. To understand their evolution, we characterized the double minutes in paired diagnosis and relapse tumors from a pediatric high-grade glioma and four adult glioblastoma patients. We determined the full structures of the major double minutes using a novel approach combining multiple types of supporting genomic evidence. Among the double minutes identified in the pediatric tumor, only one carrying EGFR was maintained at high abundance in both samples, whereas two others were resent in only trace amounts at diagnosis but abundant at relapse, and the rest were found either in the relapse sample only or in the diagnosis sample only. For the EGFR-carrying double minutes, we found a secondary somatic deletion in all copies at relapse, after erlotinib treatment, but this was rare at diagnosis, suggesting potential resistance to the EGFR inhibitor. This mutation caused an in-frame RNA transcript to skip exon 16, a novel transcript absent in EST database and in about 700 brain tumors that we reviewed. We observed similar patterns involving longitudinal copy number shift of double minutes in another four pairs (diagnosis / relapse) of adult glioblastoma. Overall, in three of five paired tumor samples, we found that although the same oncogenes were amplified at diagnosis and relapse, they were amplified on different double minutes. Our results suggest that double minutes readily evolve, increasing tumor heterogeneity rapidly. Understanding patterns of double minute evolution can shed light on future therapeutic solutions to brain tumors carrying such variants.

  Study EGAS00001003212

• C3 SNPs and outcome after lung transplantation

  Background: Development of chronic rejection is still a severe problem and causes high mortality rates after lung transplantation (LTx). Complement activation is important in the development of acute rejection (AR) and bronchiolitis obliterans syndrome, with C3 as a key complement factor. Methods: Since a single nucleotide polymorphism (SNP) in the C3 gene (rs2230199) is associated with long-term outcome after solid organ transplantation, we investigated this SNP in relation to LTx. In addition, we looked at local production of C3 by analyzing bronchoalveolar lavage fluid (BALF) of LTx patients using isoelectric focusing (IEF). Results: We demonstrated the presence of C3 in BALF and showed that this is produced by the donor lung based on the genotype of SNP rs2230199. We also analyzed donor and patient SNP configurations and observed a significant association between the SNP configuration in patients and episodes of AR during 4-years follow-up. Survival analysis showed a lower AR-free survival in homozygous C3 slow patients (p=0.005). Furthermore, we found a significant association between the SNP configuration in donors and BOS development. Patients receiving a graft from a donor with at least one C3 fast variant for rs2230199 had an inferior BOS-free survival (p=0.044). Conclusions: In conclusion, our data indicate local C3 production by donor lung cells. In addition, a single C3 SNP present in recipients affects short-term outcome after LTx, while this SNP in donors has an opposite effect on long-term outcome after LTx. These results could contribute to an improved risk stratification after transplantation.

  Study EGAS00001003843

• Molecular classification improves risk assessment in adult B-lineage ALL: Patients on the international UKALLXII-ECOG2993 trial.

  Acute lymphoblastic leukemia (ALL) in adults is a rare disease with outcomes that remain significantly inferior to those of children with ALL. While genomic classification of pediatric B-lineage ALL (B-ALL) has led to improved risk assignment and therapeutic paradigms, similar advances in adults have been lacking. The international UKALLXII/E2993 (NCT00002514) trial accrued over 2000 adult (17-64 years old) patients over 13 years, including 1229 BCR/ABL negative B-ALLs. While 93% of B-ALL achieved a remission, 41% relapsed at a median time of 13 months (Range) and overall survival (OS) at 5 years was 42% (CI). Older age and higher white blood cell (WBC) count at presentation negatively affected OS. Patients with a sibling donor assigned to allogeneic transplantation had superior OS compared to patients without donor. Randomization of patients without a donor showed an advantage of chemotherapy over autologous transplantation in first remission. Transcriptome sequencing of 94% of E2993 patients enabled genomic subtyping. We found that one-third of patients belonged to favorable genotypes (DUX4-rearranged, ETV6-RUNX1, TCF3-PBX1, PAX5 P80R, high hyperdiploidy). Of 63.4% of patients classified as high-risk based age and WBC count at diagnosis, almost 40% harbored subtype-defining genetic associations associated with favorable- or intermediate outcomes. These patients did significantly better than expected from their protocol-defined risk assignment. Our data in a large adult B-ALL cohort treated on a single international trial show the important prognostic value of genomic analysis and the potential benefit for many of the novel genotypes.

  Study EGAS00001004638

• Colorectal adenomas, carcinomas and adjacent normal NKI-AvL TGO series NGS-ProToCol

  Cancer is caused by changes in the genome of cells, resulting in aberrant transcripts and proteins. In order to understand why normal cells become cancer cells and how we can identify and destroy them, the CTMM-NGS-ProToCol project aimed to understand prostate and colorectal cancer through DNA and RNA molecular profiling, to further improve diagnosis, prognosis and treatment.The state-of-the-art within the field of genome sequencing makes it possible to identify all the modifications in our genome that encode for RNA and of the transcripts themselves. The latest development in RNA sequencing is that if one does not select for polyA RNA, but first removes rRNA from the total RNA and then performs ‘random’ RNA sequencing, 30-60% of the reads are intronic. Since about 40% of the genome consists of genes (and only 1.6% is exonic), deep RNA sequencing will cover not only the exons, but also a large portion of the introns and therefore much of the genome. The power of the combined sequencing of genome and transcriptome is the full view of copy number aberrations (CNA), exon mutations and the consequence and relevance of the mutations at the RNA level in the form of differential gene expression, alternative splicing, alternative promoter usage, novel transcripts, fusion transcripts, read-through transcripts and mutations. For the colorectal (tumor) tissue dataset, we applied molecular profiling to 30 colorectal adenomas, 30 colorectal carcinomas and 18 normal adjacent colon tissues.

  Study EGAS00001002854

• Efficacy of nivolumab in pediatric cancers with high mutation burden and mismatch-repair deficiency

  Purpose: Checkpoint-inhibitors have limited efficacy for children with unselected solid and brain tumors. We report the first prospective pediatric trial (NCT02992964) using nivolumab exclusively for refractory non-hematological cancers harboring tumor mutation burden (TMB) ≥5 mutations/megabase (mut/Mb) and/or mismatch-repair deficiency (MMRD). Patients and methods: Twenty patients were screened, and ten ultimately included in the response cohort of whom nine had TMB >10mut/Mb (three initially eligible based on MMRD) and one patient had TMB between 5-10 mut/Mb. Results: Delayed immune responses contributed to best overall response of 50%, improving on initial objective responses (20%) and leading to 2-year overall survival (OS) of 50% (95% CI; 27, 93). Four children, including three with refractory malignant gliomas are in complete remission at a median follow-up of 37-months (range: 32.4-60), culminating in 2-year OS of 43% (95% CI; 18.2, 100). Biomarker analyses confirmed benefit in children with germline MMRD, microsatellite instability, higher activated and lower regulatory circulating T-cells. Stochastic mutation accumulation driven by underlying germline MMRD impacted the tumor microenvironment, contributing to delayed responses. No benefit was observed in the single patient with a MMR-proficient tumour and TMB 7.4 mut/Mb. Conclusions: Nivolumab resulted in durable responses and prolonged survival for the first time in a pediatric trial of refractory hypermutated cancers including malignant gliomas. Novel biomarkers identified here need to be translated rapidly to clinical care to identify children who can benefit from checkpoint-inhibitors, including for upfront management of their cancers.

  Study EGAS00001007393

• Immunodeficiency syndrome caused by LCP1 mutations

  Severe congenital neutropenia (SCN) is characterized by neutropenia, recurrent infections and an increased leukemia risk. Multiple genetic defects underlying SCN have been identified, but a genetic diagnosis is still lacking in a significant proportion of patients. Here, we report three independent pedigrees with autosomal dominant variants in LCP1. Variants c.740-1G>T and c.740-20_744del resulted in the same alternatively spliced RNA product, causing an in-frame deletion (p.A247_E254del). Variant c.509C>T in the third pedigree resulted in p.S170L. Variant carriers suffer from neutropenia, poor or complete lack of response to G-CSF treatment, and variable degrees of lymphopenia. Patients with A247_E254del presented with tetraploid cells in the bone marrow, indicative of disturbed cytokinesis. In one of these kindreds, two individuals developed acute leukemia. G-CSF non-responsiveness and defective cell cycling were repaired upon correction of the LCP1 A247_E254del variant in patient-derived induced pluripotent stem cells, supporting the monogenic origin of the disease. Indicative of their gain-of-function, both A247_E254del and S170L variants increased F-actin bundling and formation of abnormal protrusions. Single-cell transcriptome analysis of A247_E254del bone marrow-derived hematopoietic stem and progenitor cells (HSPCs) showed deregulation of signaling pathways controlling mitosis in multi-lineage and lymphoid-primed HSPC subsets. We conclude that activating LCP1 variants cause a new autosomal dominant hematopoietic disorder. Depending on the consequences of the LCP1 variants for protein structure, patients may suffer from G-CSF refractory severe neutropenia, lymphopenia, defective cytokinesis and predisposition to leukemia.

  Study EGAS00001008293

• Combination of ribociclib and gemcitabine for the treatment of medulloblastoma

  Group 3 (G3) medulloblastoma (MB) is one of the deadliest forms of the disease for which novel treatment is desperately needed. Here we evaluate ribociclib, a highly selective CDK4/6 inhibitor, with gemcitabine in mouse and human G3 MBs. Ribociclib CNS penetration was assessed by in vivo microdialysis and by immunohistochemistry and gene expression studies. Survival studies to determine the efficacy of ribociclib and gemcitabine combination were performed on mice orthotopically implanted with luciferase labelled mouse and human G3 MB. Pharmacokinetic-pharmacodynamic outcomes and univariable survival models were analyzed to estimate survival. Gene activity inference using NetBID and tumor differentiation analysis investigated the effects of the combination after short and long-term treatments. Tumors from mice treated with oral ribociclib displayed inhibited RB phosphorylation, downregulated E2F target genes, and decreased proliferation. Treatment of mice with the combination of ribociclib and gemcitabine was well tolerated, slowed tumor progression and metastatic spread, and increased survival. Molecular analysis of treated versus untreated tumors showed a significant decrease in the activity and expression of genes involved in cell cycle progression and DNA damage response, and an increase in activity and expression of genes implicated in neuronal identity and neuronal differentiation. Ribociclib is CNS-penetrant. When administered/combined with gemcitabine in orthotopic G3 MB models resulted in improved survival. Our findings, with both mouse and human patient-derived-orthotopic xenograft models, suggest that this combination therapy has promise for children with G3 MB and may represent an effective treatment strategy for other CNS malignancies.

  Study EGAS00001006001

• NIDA Genetic Epidemiology of Opioid Dependence in Bulgaria (GEODB)

  The study was conducted in Bulgaria as a collaboration between the Molecular Medicine Center (Medical University, Sofia), the Bulgarian Addictions Institute (Sofia), the Initiative for Health Foundation (Sofia) and Washington University School of Medicine (Saint Louis, MO, USA). This is a case-population control study. Participants (N=2,499 interviews; N=1,995 with GWAS data) in our study are primarily active heroin users (78%) aged 18 and over, with a median 8.9 years of daily heroin use (minimum of 12 months). Virtually all participants (99.1%) qualified for a lifetime DSM-IV diagnosis of dependence, symptom endorsement probabilities ranging from 77% to 99.3%; and 61% endorsing all symptoms. 85% were heroin injectors and 97% reported using (or having used) heroin daily. Anonymized, population-representative control samples (no phenotypic data, N = 1,062 with GWAS data) were drawn from the MMC repository. Unlike other studies, where samples are clinically ascertained (e.g., from ORT programs), our participants are primarily untreated. PTSD, major depression, suicidality, mania, alcohol, nicotine and substance dependence (separating heroin and opioids) were assessed using the MAGIC (Todd et al., 2003, PMID: 14627881), a broad semi-structured psychiatric assessment tool with good reliability and prospective stability. The onset of (any) illicit drug use in this sample is not particularly remarkable (age~16), but the age of onset of heroin use is much lower than in the USA: 25% by age 16; 50% by age 19, with no differences between ethnicities or gender. This is consistent with findings from other studies in Bulgaria. In contrast, in 2008, SAMHSA estimated an average age of 23.4 for new heroin initiates in the USA. Further, progression from first use to regular use appears to be more rapid, with the majority of participants reporting onset of dependence problems within one year of initiation. Another unique aspect of this study population are the comparatively low levels of polysubstance use (outside of nicotine and alcohol). This early-use, fast-transition and monosubstance heroin pattern stands in sharp contrast to what is reported in many studies in the Western World. In our study, 47% of Ethnic Bulgarians and 66% of Roma used only opioids, even years after the onset of drug use. 15.4% of Ethnic Bulgarians and 66.2% of Roma reported heroin as the very first illicit drug used. Lifetime, 12.5% of Ethnic Bulgarians and 52.8% of Roma report never having used another illicit drug other than heroin more than five times. While both Roma and Ethnic Bulgarians certainly experiment with other drugs, abuse/dependence rates for these drugs are low in Ethnic Bulgarians (from 8.4% for inhalants to 28% for stimulants) and in the Roma population (from 1.3% for hallucinogens to 11.2% for stimulants).

  Study phs001804

• The International Consortium for Prostate Cancer Genetics Genome Wide Association Study of Familial Prostate Cancer

  Initially, the ICPCG focused largely on high-risk prostate cancer pedigrees using linkage analysis. However, association studies have also been informative to find prostate cancer susceptibility variants in the genome. We hypothesize that genome-wide (GW) association studies of familial cases of prostate cancer will have the power to identify rarer and perhaps less penetrant risk variants associated with prostate cancer than have been identified to date. Our approach will be to examine evidence for association in selected, independent cases from high-risk pedigrees; we hypothesize that they represent a more homogeneous set of cases with potentially different associations. Use of the 5M plus exome SNP platform will allow us to include in our search more rare variants in our search than have ever been investigated for prostate cancer. Aim 1. Identify a set of independent prostate cancer cases selected from ICPCG high-risk prostate cancer pedigrees that have 3 or more related prostate cancer cases and have an average age at diagnosis ≤ 75 years. Identify appropriate matched controls from participating ICPCG groups/ populations. Aim 2. Perform GW SNP genotyping with the Illumina 5M plus exome SNP set on the set of independent prostate cancer cases and controls described in Aim 1. Aim 3. Perform association analyses appropriately matching controls for different ICPCG populations and groups. There will be a two-stage design for confirmation. Aim 4. Test reported associations using the extensive sample set available to us by collaboration with the PRACTICAL consortium that has access to 50 000 DNA samples from 34 groups internationally (over 7,000 of whom are positive for prostate cancer family history).

  Study phs000733

• Nala TAS-LRS PGx Study

  Sequencing was performed on the PromethION Flow Cell R10 (M version) using the P2 Solo Sequencer (MinION release 24.02.16). The library was divided into three portions and loaded in a tapered manner across three time points. At the first time point, the initial portion of the library was loaded, and sequencing began in whole-genome mode (without adaptive sampling), to monitor QC (N50 within the expected range). After one hour, adaptive sampling was activated. A custom BED file was used to define the target regions (N=326). Each region was extended by 20 kb upstream and downstream, and overlapping regions were merged into non-redundant intervals using bedtools43, covering a total of 1.3% of the human genome. At the second time point (20–24 hours after sequencing began, or when fewer than 2000 pores remained active), the flow cell was washed following ONT’s Flow Cell Wash Kit protocol, and the second portion of the library was loaded. At the third time point (40–48 hours), the second portion of the library was retrieved, and merged with the third portion. The flow cell was washed and reloaded with the mixed library. POD5 files were basecalled using Dorado v0.8.1 in super-accuracy (SUP) mode with the dna_r10.4.1_e8.2_400bps_SUP@v5.0.0. Reads from the initial 1 h Whole Genome Sequencing (WGS) and subsequent 72 h adaptive sampling were filtered for Q-scores >10. Passing reads were demultiplexed using Dorado’s demux function, then combined per sample and mapped to the GRCh38 reference genome using Minimap2 v2.22. Files were converted to CRAM using samtools.

  Dataset EGAD50000001609

• Reference Standards for Mosaic Variant Detection

  After conception, postzygotic mutations continuously occur throughout life in humans, causing somatic mosaicism in an individual. The variant type, time of origination, and locations of the mosaic mutations result in unique mosaic patterns in a combinatorial manner and further affect phenotypes, including various noncancerous diseases. Several efforts have, thus, been made to identify the mutational landscape and mechanisms underlying the mosaic mutations. From a technical aspect, the accurate detection of mutations is at the core of the mosaicism research, and the construction of a standard reference is a critical first step to serve as the basis for analytical validation and benchmarks for germline and somatic mutation detection. Furthermore, a reference standard for mosaic mutations is urgently needed to enable more advanced research.Herein, we generated robust, large-scale, and cell line mixture-based reference standards that contain abundant mosaic SNVs and INDELs along with wild-type sites and germ line variants. Moreover, the whole reference standard set mimics the cumulative aspect of mosaic variant acquisition in the early developmental stage through a progressive cell line mixing with confirmed genotypes. It can be used for optimizing the current use of mosaic variant detection strategies, as well as developing algorithms for future improvements.We previously generated an NCBI BioProject (PRJNA758606) to release much of these data. Only the data that are subject to authorized access constraints have been included in this submission to dbGaP. The two data sources are thus, complementary to each other.

  Study phs003399

• Genome-Wide Association Study of Celiac Disease

  Celiac disease (gluten-sensitive enteropathy, celiac sprue) is a common disease with significant morbidity and mortality. It is caused by sensitivity to the dietary protein gluten, resulting in a chronic enteropathy in the small intestine. Celiac disease is now recognized to be a common disease, with reports that the disease frequency is 1:133 in the United States, similar to European estimates. There is recent evidence to suggest that the incidence of the disease is rising. Occult disease is frequently present with minimal classic symptoms or signs. The ratio of symptomatic to asymptomatic celiac disease is estimated to be 1:7. Some complications of celiac disease include lymphoma, osteoporosis, anemia, miscarriages, seizures, vitamin deficiencies, and co-occurrence of other autoimmune diseases. The only treatment is a gluten-free diet, so that recurrence of symptoms and complications may occur after minor dietary indiscretions. Identifying the underlying genetic causes of celiac disease may allow us to identify susceptible individuals, as well as advance new ways to prevent the disease and to treat it once it occurs. Several genome-wide linkage studies and one genome-wide association study of celiac disease have been conducted. Other than the common locus at HLA, few putative celiac disease loci have been replicated between studies, suggesting that the disease is heterogeneous and complex. A portion of the genetic predisposition can be attributed to HLA, but the etiology is likely due to a number of rare, high penetrant genes (as would be identified in linkage analysis) and to more common, low penetrant genes (as would be identified in association studies). The objective of this study is to identify new loci that increase risk to develop celiac disease. We will capitalize on existing North American resources, including three large collections of celiac cases and controls (Aim 1) and an independent set of celiac cases and their families (Aim 3). We propose a comprehensive multi-stage approach, with the following specific aims. In Aim 1, we will conduct a genome-wide association (GWA) study of single nucleotide polymorphisms (SNPs) and copy number variants (CNVs). The GWA will include1900 disease cases and 3400 matched controls, genotyped using the Illumina Human 610-quad chip. Statistical analyses will be performed to test for associations with celiac disease. In Aim 2, we will conduct a combined analysis of our GWA dataset from Aim 1 and a previous GWA dataset to identify additional low-penetrance loci. In Aim 3, we will attempt to replicate significant findings from the GWA study in two independent sample sets. At the conclusion of this study, we expect to have validated a number of SNPs and CNPs from regions in the genome that alter the risk of developing celiac disease. These SNPs may prove useful at both the clinical and research level. The data from the study will be shared with the scientific community.

  Study phs000274