13415 results for ""pdc"+"heritage+language"+census+study"

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• GENOMIC MUTATION LANDSCAPE OF SKIN CANCERS FROM DNA REPAIR-DEFICIENT XERODERMA PIGMENTOSUM PATIENTS

  Xeroderma pigmentosum (XP) is a genetic disorder caused by mutations in genes of the Nucleotide Excision Repair (NER) pathway (groups A-G) or in Translesion Synthesis (TLS) DNA polymerase η (group V). XP is associated with an increased skin cancer risk, reaching, for some groups, several thousand-fold compared to the general population. Here, we analyzed 38 skin cancer genomes from five XP groups. We found that the activity of NER determines heterogeneity of the mutation rates across skin cancer genomes and that transcription-coupled NER extends beyond the gene boundaries reducing the intergenic mutation rate. Mutational profile in XP-V tumors revealed the role of polymerase η in the error-free bypass of (i) rare TpG and TpA DNA lesions, (ii) 3’ nucleotides in pyrimidine dimers, and (iii) TpT photodimers. Our study unravels the genetic basis of skin cancer risk in XP and provides insights into the mechanisms reducing UV-induced mutagenesis in the general population.

  Study EGAS00001006732

• Comprehensive epigenomic profiling reveals the extent of disease-specific chromatin states and informs drug target discovery in ankylosing spondylitis

  Ankylosing spondylitis (AS) is a common, highly heritable inflammatory arthritis characterised by enthesitis of the spine and sacroiliac joints. Genome-wide association studies have revealed >100 genetic associations but their functional effects remain largely unresolved. Here, we present a comprehensive transcriptomic and epigenomic map of disease-relevant blood immune cell subsets from AS patients and healthy controls. We report differential disease signatures for specific genomic regions from individual -omic modalities and multi-omic integration, showing enrichment at genetically associated loci and evidence for altered monocyte function in AS. We link putative functional SNPs with cognate genes using high-resolution Capture-C at 10 loci, including PTGER4 and ETS1. We also show how disease-specific functional genomic data can be integrated with GWAS evidence to enhance therapeutic target discovery. This study combines multiple epigenetic and transcriptional analysis with GWAS to identify cell types, candidate drug target genes and transcriptional regulation of likely pathogenic relevance.

  Study EGAS00001006945

• The chromatin accessibility signature of human immune aging stems from CD8+ T cells

  Aging is linked to deficiencies in immune responses and increased systemic inflammation. To unravel the regulatory programsbehind these changes, we applied systems immunology approaches and profiled chromatin accessibility and the transcriptomein PBMCs, purified monocytes, and B and T cells. Analysis of samples from 77 young and elderly donors revealed a novel androbust aging signature in PBMCs, with simultaneous systematic chromatin closing at promoters and enhancers associated withT cell signaling and a potentially stochastic chromatin opening mostly found at quiescent and repressed sites. Combined analysesof chromatin accessibility and the transcriptome uncovered immune molecules activated/inactivated with aging andidentified the silencing of the IL7R gene and the IL-7 signaling pathway genes as potential biomarkers. This signature is borneby memory CD8+ T cells, which exhibited an aging-related loss in binding of NF-κB and STAT factors. Thus, our study providesa unique and comprehensive approach to identifying candidate biomarkers and provides mechanistic insights into aging-associatedimmunodeficiency.

  Study EGAS00001002605

• An isogenic human iPSC model unravels neurodevelopmental abnormalities in SMA

  Whether neurodevelopmental defects underlie the selective neuronal death that characterizes neurodegenerative diseases is becoming an intriguing question. To address it, we focused on the motor neuron (MN) disease Spinal Muscular Atrophy (SMA), caused by reduced levels of the ubiquitous protein SMN. Taking advantage of the first isogenic human induced pluripotent stem cell-derived SMA model that we have generated and a spinal cord organoid system, here we report that the relative and temporal expression of early neural progenitor and MN markers is altered in SMA. Furthermore, the corrected isogenic controls only partially reverse these abnormalities. These findings raise the relevant clinical implication that SMN-increasing treatments might not fully amend SMA pathological phenotypes. The approach we have taken demonstrates that the discovery of new disease mechanisms is greatly improved by using human isogenic models. Moreover, our study implies that SMA has a developmental component that might trigger the MN degeneration.

  Study EGAS00001007259

• Pediatric Patient-Derived-Xenograft development in MAPPYACTS – international pediatric cancer precision medicine trial in relapsed and refractory tumors

  Pediatric patients with recurrent and refractory cancers are in most need for new treatments. This study developed patient-derived-xenograft (PDX) models within the European MAPPYACTS cancer precision medicine trial (NCT02613962). To date, 131 PDX models were established following heterotopical and/or orthotopical implantation in immunocompromised mice: 76 sarcomas, 25 other solid tumors, 12 central nervous system tumors, 15 acute leukemias, and 3 lymphomas. PDX establishment rate was 43%. Histology, whole exome and RNA sequencing revealed a high concordance with the primary patient’s tumor profile, human leukocyte-antigen characteristics and specific metabolic pathway signatures. A detailed patient molecular characterization, including specific mutations prioritized in the clinical molecular tumor boards are provided. Ninety models were shared with the IMI2 ITCC Paediatric Preclinical Proof-of-concept Platform (IMI2 ITCC-P4) for further exploitation. This new PDX biobank of unique recurrent childhood cancers provides an essential support for basic and translational research and new treatments development in advanced pediatric malignancies.

  Study EGAS00001007327

• Drug screening reveals new insight for chemoresistant hepatoblastoma

  Hepatoblastoma (HB) is the most prevalent form of pediatric liver cancer. Although the standard treatment, primarily based on cisplatin, is effective in 80% of patients, it falls short in high-risk cases due to the development of chemoresistance. To identify new therapies overcoming this resistance, we screened 101 individual therapeutic compounds and 58 combinations, across 8 pediatric liver cancer cell lines. We identified ATR as a critical target to reverse cisplatin resistance. The ATR inhibitor elimusertib demonstrated the greatest synergy with cisplatin in 2D and 3D cultures and in subcutaneous xenograft models of cisplatin-resistant HB. This combination was found to enhance DNA damage and induces apoptosis through strong p53 activation. In conclusion, our study underscores the crucial role of ATR in cisplatin resistance and highlights the promising anti-proliferative effects of the Elimusertib/Cisplatin combination in cisplatin-resistant HB models, offering a potential new therapeutic option for treating high-risk and refractory HB.

  Study EGAS00001007916

• The genomic landscape of relapsed infant and childhood KMT2A-rearranged acute leukemia

  To study the mechanisms of relapse in KMT2A-rearranged (KMT2A-r) acute lymphoblastic (ALL) and acute myeloid leukemia (AML), we performed whole-genome and exome sequencing of infants and children with relapsed ALL/AML (n=36), and longitudinal deep-sequencing of 257 samples in 30 patients. Somatic alterations in drug-response genes, most commonly in TP53 and IKZF1 (64%), were highly enriched in early relapse ALL (79%, 9-36 months after diagnosis), but rare in very early relapse ALL (<9 months, 9%). A marked chemotherapy-exposure signature was detected for mutations in early relapse ALL but not in very early ALL or AML relapse, in line with different mechanisms of relapse. Longitudinal analyses could track residual leukemia cells, clonal drug responses, and the upcoming relapse. These results highlight that KMT2A-r ALL and AML evade therapy differently and provide new insights into the mechanisms of relapse in this highly lethal form of pediatric acute leukemia.

  Study EGAS00001008197

• Atypical tetrasomy 18 in a hepatoblastoma patient

  Constitutive aneuploidy often underlies developmental defects, while copy-number alterations are recurrent somatic events in cancers. Rarely, mosaic aneuploidy links developmental defects and cancer development, yet its molecular basis remains elusive. We report the first cancer case in a tetrasomy 18 patient—a female who developed hepatoblastoma at age two and remains recurrence-free 24 months post-surgery and chemotherapy. Whole-genome sequencing and Fluorescent in situ hybridization (FISH) uncovered a complex rearrangement with eight breakpoints between 18p11.32 to 18q12.1, present in 10% of liver and blood cells. Haplotype analysis revealed a pre-zygotic origin, with mosaicism arising from early rescue by loss of the rearranged chromosome. Strikingly, all tumor cells retained this rearranged chromosome. Single-nucleus RNA-seq of liver and hepatoblastoma tissue traced the aneuploidy’s evolution during gametogenesis, organogenesis, and tumorigenesis. This study provides insights into mechanisms of aneuploidy-driven cancer, highlighting the interplay of mosaicism, developmental defects, and tumor evolution in a rare genetic syndrome.

  Study EGAS00001008072

• Single molecule genome-wide mutation profiles of cell-free DNA for non-invasive detection of cancer

  Somatic mutations are a hallmark of tumorigenesis and may be useful for non-invasive diagnosis of cancer. We analyzed whole-genome sequencing (WGS) data from 2,511 individuals in the Pan-Cancer Analysis of Whole Genomes (PCAWG) study as well as 489 individuals from four prospective cohorts and found distinct regional and mutation type specific frequencies in tissue and cell-free DNA (cfDNA) of cancer patients that were associated with replication timing and other chromatin features. A machine learning model using genome-wide mutational profiles combined with other features and followed by CT imaging detected >90% of lung cancer patients, including those with stage I and II disease. The fixed model was validated in an independent cohort, detected patients with cancer earlier than standard approaches, and could be used to monitor response to therapy. This approach lays the groundwork for non-invasive cancer detection using genome-wide mutation features that may facilitate cancer screening and monitoring.

  Study EGAS00001007248

• White blood cell and cell-free DNA analyses for detection of residual disease in gastric cancer

  Liquid biopsies are providing new opportunities for detection of residual disease in cell-free DNA (cfDNA) after surgery but may be confounded through identification of alterations arising from clonal hematopoiesis. Here, we identify circulating tumor-derived DNA alterations (ctDNA) through ultrasensitive targeted sequencing analyses of matched cfDNA and white blood cells from the same patient. We apply this approach to analyze samples from patients in the CRITICS trial, a phase III randomized controlled study of perioperative chemotherapy in patients with operable gastric cancer. After filtering alterations derived from matched white-blood cells, the presence of ctDNA predicts recurrence when analyzed within nine weeks after preoperative treatment and after surgery in patients eligible for multimodal treatment. These analyses provide a facile method for distinguishing ctDNA from other cfDNA alterations and highlight the utility of ctDNA as a predictive biomarker of patient outcome to perioperative cancer therapy and surgical resection in patients with gastric cancer.

  Study EGAS00001004114