Publications by authors named "LOO P"

Optimizing prevention and early detection of cancer requires understanding the number, types and timing of driver mutations. To quantify this, we exploited the elevated cancer incidence and mutation rates in germline and carriers. Using novel statistical models, we identify genomic deletions as the likely rate-limiting mutational processes, with 1-3 deletions required to initiate breast and ovarian tumors.

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Disruption of the class I human leukocyte antigen (HLA) molecules has important implications for immune evasion and tumor evolution. We developed major histocompatibility complex loss of heterozygosity (LOH), allele-specific mutation and measurement of expression and repression (MHC Hammer). We identified extensive variability in HLA allelic expression and pervasive HLA alternative splicing in normal lung and breast tissue.

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  • Oral potentially malignant disorders (OPMDs) with genomic changes have a higher chance of turning into oral squamous cell carcinoma (OSCC), and while tissue biopsies provide genomic data, they are invasive.
  • This pilot study explores the effectiveness of non-invasive brush biopsies in profiling the genomic landscape of a patient with both OPMD and OSCC, revealing that brush biopsies accurately captured 90% of single nucleotide variants (SNVs) and matched copy number profiles with tissue biopsies.
  • The results suggest that brush biopsies can identify shared genomic alterations between OPMD and OSCC lesions, showcasing their potential for understanding tumor evolution and ancestry without the need for invasive procedures.
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  • Oncogenes can become activated through mechanisms like enhancer hijacking and mutations that generate new enhancers or promoters, helping researchers understand variations in noncoding cancer genomes.
  • A new mechanism is identified where the loss of an intronic element in the FTO gene causes abnormal expression of the IRX3 oncogene in T cell acute lymphoblastic leukemia (T-ALL).
  • The study suggests that 'promoter tethering' helps keep oncogenes inactive by linking them to non-functioning parts of the genome, which may act as a safeguard against tumor development.
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We discovered high-titer neutralizing autoantibodies against interleukin-10 in a child with infantile-onset inflammatory bowel disease (IBD), a phenocopy of inborn errors of interleukin-10 signaling. After B-cell-depletion therapy and an associated decrease in the anti-interleukin-10 titer, conventional IBD therapy could be withdrawn. A second child with neutralizing anti-interleukin-10 autoantibodies had a milder course of IBD and has been treated without B-cell depletion.

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Intra-tumor heterogeneity is an important driver of tumor evolution and therapy response. Advances in precision cancer treatment will require understanding of mutation clonality and subclonal architecture. Currently the slow computational speed of subclonal reconstruction hinders large cohort studies.

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Background: Lynch syndrome (LS) is under-diagnosed. UK National Institute for Health and Care Excellence guidelines recommend multistep molecular testing of all colorectal cancers (CRCs) to screen for LS. However, the complexity of the pathway has resulted in limited improvement in diagnosis.

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Tumors frequently display high chromosomal instability and contain multiple copies of genomic regions. Here, we describe Gain Route Identification and Timing In Cancer (GRITIC), a generic method for timing genomic gains leading to complex copy number states, using single-sample bulk whole-genome sequencing data. By applying GRITIC to 6,091 tumors, we found that non-parsimonious evolution is frequent in the formation of complex copy number states in genome-doubled tumors.

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Subclonal reconstruction algorithms use bulk DNA sequencing data to quantify parameters of tumor evolution, allowing an assessment of how cancers initiate, progress and respond to selective pressures. We launched the ICGC-TCGA (International Cancer Genome Consortium-The Cancer Genome Atlas) DREAM Somatic Mutation Calling Tumor Heterogeneity and Evolution Challenge to benchmark existing subclonal reconstruction algorithms. This 7-year community effort used cloud computing to benchmark 31 subclonal reconstruction algorithms on 51 simulated tumors.

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The investigation of the mechanisms behind p53 mutations in acute myeloid leukemia (AML) has been limited by the lack of suitable mouse models, which historically have resulted in lymphoma rather than leukemia. This study introduces two new AML mouse models. One model induces mutant p53 and Mdm2 haploinsufficiency in early development, showing the role of Mdm2 in myeloid-biased hematopoiesis and AML predisposition, independent of p53.

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In the evolution of species, the karyotype changes with a timescale of tens to hundreds of thousand years. In the development of cancer, the karyotype often is modified in cancerous cells over the lifetime of an individual. Characterizing these changes and understanding the mechanisms leading to them has been of interest in a broad range of disciplines including evolution, cytogenetics, and cancer genetics.

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  • Women have shown a long-standing commitment and intelligence in the field of animal behavior and welfare.
  • Their contributions have included innovative ideas and research that advance the understanding of these subjects.
  • Historically, despite facing challenges, their impact has been significant and noteworthy in the scientific community.
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Head and neck cancer radiotherapy often damages salivary glands and oral mucosa, severely negatively impacting patients' quality of life. The ability of FLASH proton radiotherapy (F-PRT) to decrease normal tissue toxicity while maintaining tumor control compared with standard proton radiotherapy (S-PRT) has been previously demonstrated for several tissues. However, its potential in ameliorating radiation-induced salivary gland dysfunction and oral mucositis and controlling orthotopic head and neck tumor growth has not been reported.

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The basal breast cancer subtype is enriched for triple-negative breast cancer (TNBC) and displays consistent large chromosomal deletions. Here, we characterize evolution and maintenance of chromosome 4p (chr4p) loss in basal breast cancer. Analysis of The Cancer Genome Atlas data shows recurrent deletion of chr4p in basal breast cancer.

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Mutations in proteasome β-subunits or their chaperone and regulatory proteins are associated with proteasome-associated autoinflammatory disorders (PRAAS). We studied six unrelated infants with three de novo heterozygous missense variants in PSMB10, encoding the proteasome β2i-subunit. Individuals presented with T-B-NK± severe combined immunodeficiency (SCID) and clinical features suggestive of Omenn syndrome, including diarrhea, alopecia, and desquamating erythematous rash.

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Health insurance is one of the main financing mechanisms currently being used in low and middle-income countries to improve access to quality services. Tanzania has been running its National Health Insurance Fund (NHIF) since 2001 and has recently undergone significant reforms. However, there is limited attention to the causal mechanisms through which NHIF improves service coverage and quality of care.

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The development of cancer is an evolutionary process involving the sequential acquisition of genetic alterations that disrupt normal biological processes, enabling tumor cells to rapidly proliferate and eventually invade and metastasize to other tissues. We investigated the genomic evolution of prostate cancer through the application of three separate classification methods, each designed to investigate a different aspect of tumor evolution. Integrating the results revealed the existence of two distinct types of prostate cancer that arise from divergent evolutionary trajectories, designated as the Canonical and Alternative evolutionary disease types.

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Mutational processes that alter large genomic regions occur frequently in developing tumors. They range from simple copy number gains and losses to the shattering and reassembly of entire chromosomes. These catastrophic events, such as chromothripsis, chromoplexy and the formation of extrachromosomal DNA, affect the expression of many genes and therefore have a substantial effect on the fitness of the cells in which they arise.

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Small cell lung cancer (SCLC) is an aggressive malignancy composed of distinct transcriptional subtypes, but implementing subtyping in the clinic has remained challenging, particularly due to limited tissue availability. Given the known epigenetic regulation of critical SCLC transcriptional programs, we hypothesized that subtype-specific patterns of DNA methylation could be detected in tumor or blood from SCLC patients. Using genomic-wide reduced-representation bisulfite sequencing (RRBS) in two cohorts totaling 179 SCLC patients and using machine learning approaches, we report a highly accurate DNA methylation-based classifier (SCLC-DMC) that can distinguish SCLC subtypes.

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  • The authors discuss how causal loop diagrams help illustrate the unexpected negative effects of COVID-19 policies on maternal health.
  • They emphasize that these diagrams can provide insights into past outcomes, allowing for a better understanding of the consequences.
  • Additionally, the authors suggest that these tools could be useful for future decision-making to avoid similar negative impacts.
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Intestinal metaplasia (IM) is a pre-malignant condition of the gastric mucosa associated with increased gastric cancer (GC) risk. Analyzing 1,256 gastric samples (1,152 IMs) across 692 subjects from a prospective 10-year study, we identify 26 IM driver genes in diverse pathways including chromatin regulation (ARID1A) and intestinal homeostasis (SOX9). Single-cell and spatial profiles highlight changes in tissue ecology and IM lineage heterogeneity, including an intestinal stem-cell dominant cellular compartment linked to early malignancy.

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Most computational methods that infer somatic copy number alterations (SCNAs) from bulk sequencing of DNA analyse tumour samples individually. However, the sequencing of multiple tumour samples from a patient's disease is an increasingly common practice. We introduce Refphase, an algorithm that leverages this multi-sampling approach to infer haplotype-specific copy numbers through multi-sample phasing.

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  • - The study examines the genomic heterogeneity of prostate cancer and its impact on treatment resistance, suggesting that incorporating evolutionary principles into clinical trials could provide valuable insights for therapy strategies.
  • - Researchers analyzed whole genome data and 3D anatomical structures from two patients with high-risk prostate cancer, using advanced tools to map tumor origins, genetic mutations, and metastasis patterns.
  • - Results indicate that specific mutations and evolutionary patterns significantly influence cancer progression and metastasis, highlighting the potential for evolutionary analysis to inform therapy choices in prostate cancer patients.
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The understanding of small cell lung cancer (SCLC) biology has increased dramatically in recent years, but the processes that allow SCLC to progress rapidly remain poorly understood. Here, we advocate the integration of rapid autopsies and preclinical models into SCLC research as a comprehensive strategy with the potential to revolutionize current treatment paradigms.

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