Publications by authors named "Burkett S"

Article Synopsis
  • * The newly developed PAMless Cas enzyme, SpRY, allows for higher efficiency and specificity in correcting X-CGD mutations, particularly through the use of the adenine base editor ABE8e-SpRY, which achieved up to 70% mutation correction in hematopoietic stem and progenitor cells (HSPCs).
  • * Investigations into potential off-target effects showed minimal unintended edits, and the success of these techniques in mouse models supports the initiation of first-in-human
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Primary fibroblasts from six individuals with CLN3-related conditions were used to generate induced pluripotent stem cell (iPSC) lines CHDTRi001-B, CHDTRi002-B, CHDTRi003-A, CHDTRi004-B, CHDTRi005-A, and CHDTRi006-E through the expression of four reprogramming factors: human OCT3/4, KLF4, SOX2, and c-MYC. The iPSC lines were characterized to confirm their pluripotency via immunocytochemistry, flow cytometry, and teratoma formation. Genomic stability, cell line identity, and CLN3 genotype were confirmed.

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Introduction: We examined the association of clinical, microbiological, and host response features of periodontitis with MRI markers of atrophy/cerebrovascular disease in the Washington Heights Inwood Columbia Aging Project (WHICAP) Ancillary Study of Oral Health.

Methods: We analyzed 468 participants with clinical periodontal data, microbial plaque and serum samples, and brain MRIs. We tested the association of periodontitis features with MRI features, after adjusting for multiple risk factors for Alzheimer's disease/Alzheimer's disease-related dementia (AD/ADRD).

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Loss of BRCA2 (breast cancer 2) is lethal for normal cells. Yet it remains poorly understood how, in BRCA2 mutation carriers, cells undergoing loss of heterozygosity overcome the lethality and undergo tissue-specific neoplastic transformation. Here, we identified mismatch repair gene mutL homolog 1 (MLH1) as a genetic interactor of BRCA2 whose overexpression supports the viability of Brca2-null cells.

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Ectodermal appendages, such as the mammary gland (MG), are thought to have evolved from hair-associated apocrine glands to serve the function of milk secretion. Through the directed differentiation of mouse embryonic stem cells (mESCs), here, we report the generation of multilineage ESC-derived mammary organoids (MEMOs). We adapted the skin organoid model, inducing the dermal mesenchyme to transform into mammary-specific mesenchyme via the sequential activation of Bone Morphogenetic Protein 4 (BMP4) and Parathyroid Hormone-related Protein (PTHrP) and inhibition of hedgehog (HH) signaling.

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Pathogenic variants in BRCA2 are known to significantly increase the lifetime risk of developing breast and ovarian cancers. Sequencing-based genetic testing has resulted in the identification of thousands of BRCA2 variants that are considered to be variants of uncertain significance (VUS) because the disease risk associated with them is unknown. One such variant is p.

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Background: Genome integrity is essential for the survival of an organism. DNA mismatch repair (MMR) genes (e.g.

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Article Synopsis
  • - The high number of variants of uncertain significance (VUS) in cancer-related genes, particularly BRCA2, is due to insufficient epidemiological data, prompting the need for advanced functional assessments.
  • - This study introduces a CRISPR-Cas9-based high-throughput functional assay using humanized-mouse embryonic stem cells to evaluate the functional significance of 599 BRCA2 variants, including responses to DNA-damaging medications like cisplatin and olaparib.
  • - By leveraging this approach, researchers successfully categorized 252 single-nucleotide variants from BRCA2 exon 13 into functional and non-functional groups, highlighting the potential of saturation genome editing combined with drug sensitivity tests in clarifying the roles of BRCA
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We previously showed that elevated TYMS exhibits oncogenic properties and promotes tumorigenesis after a long latency, suggesting cooperation with sequential somatic mutations. Here we report the cooperation of ectopic expression of human TYMS with loss of Ink4a/Arf, one of the most commonly mutated somatic events in human cancer. Using an hTS/Ink4a/Arf genetically engineered mouse model we showed that deregulated TYMS expression in Ink4a/Arf null background accelerates tumorigenesis and metastasis.

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The small endogenous signaling molecule nitric oxide (NO) has been linked with chronic inflammation and cancer. The effects of NO are both concentration and temporally dependent; under some conditions, NO protects against damage caused by reactive oxygen species and activates P53 signaling. During chronic inflammation, NO causes DNA damage and inhibits repair proteins.

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Unlabelled: Small-cell lung cancer (SCLC) is an aggressive neuroendocrine lung cancer. Oncogenic MYC amplifications drive SCLC heterogeneity, but the genetic mechanisms of MYC amplification and phenotypic plasticity, characterized by neuroendocrine and nonneuroendocrine cell states, are not known. Here, we integrate whole-genome sequencing, long-range optical mapping, single-cell DNA sequencing, and fluorescence in situ hybridization to find extrachromosomal DNA (ecDNA) as a primary source of SCLC oncogene amplifications and driver fusions.

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Introduction: gene therapy for treatment of Inborn errors of Immunity (IEIs) have demonstrated significant clinical benefit in multiple Phase I/II clinical trials. Current approaches rely on engineered retroviral vectors to randomly integrate copy(s) of gene-of-interest in autologous hematopoietic stem/progenitor cells (HSPCs) genome permanently to provide gene function in transduced HSPCs and their progenies. To circumvent concerns related to potential genotoxicities due to the random vector integrations in HSPCs, targeted correction with CRISPR-Cas9-based genome editing offers improved precision for functional correction of multiple IEIs.

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Drug resistance is a long-standing impediment to effective systemic cancer therapy and acquired drug resistance is a growing problem for molecularly-targeted therapeutics that otherwise have shown unprecedented successes in disease control. The hepatocyte growth factor (HGF)/Met receptor pathway signaling is frequently involved in cancer and has been a subject of targeted drug development for nearly 30 years. To anticipate and study specific resistance mechanisms associated with targeting this pathway, we engineered resistance to the HGF-neutralizing antibody rilotumumab in glioblastoma cells harboring autocrine HGF/Met signaling, a frequent abnormality of this brain cancer in humans.

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Background: Breast cancer is a heterogenous disease with several histological and molecular subtypes. Models that represent these subtypes are essential for translational research aimed at improving clinical strategy for targeted therapeutics.

Methods: Different combinations of genetic aberrations (Brca1 and Trp53 loss, and inhibition of proteins of the Rb family) were induced in the mammary gland by injection of adenovirus expressing Cre recombinase into the mammary ducts of adult genetically engineered mice.

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Poly (ADP-ribose) polymerase inhibitors (PARPis) represent a major advance in ovarian cancer, now as a treatment and as a maintenance therapy in the upfront and recurrent settings. However, patients often develop resistance to PARPis, underlining the importance of dissecting resistance mechanisms. Here, we report different dosing/timing schemes of PARPi treatment in BRCA2-mutant PEO1 cells, resulting in the simultaneous development of distinct resistance mechanisms.

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Clinical studies of cancer patients have shown that overexpression or amplification of thymidylate synthase (TS) correlates with a worse clinical outcome. We previously showed that elevated TS exhibits properties of an oncogene and promotes pancreatic neuroendocrine tumors (PanNETs) with a long latency. To study the causal impact of elevated TS levels in PanNETs, we generated a mouse model with elevated human TS (hTS) and conditional inactivation of the Men1 gene in pancreatic islet cells (hTS/Men1-/-).

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Malignant mesothelioma (MMe) is a rare malignancy originating from the linings of the pleural, peritoneal and pericardial cavities. The best-defined risk factor is exposure to carcinogenic mineral fibers (e.g.

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The interaction between tumor suppressor BRCA2 and DSS1 is essential for RAD51 recruitment and repair of DNA double stand breaks (DSBs) by homologous recombination (HR). We have generated mice with a leucine to proline substitution at position 2431 of BRCA2, which disrupts this interaction. Although a significant number of mutant mice die during embryogenesis, some homozygous and hemizygous mutant mice undergo normal postnatal development.

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Mechanical signals from the extracellular microenvironment have been implicated in tumor and metastatic progression. Here, we identify nucleoporin NUP210 as a metastasis susceptibility gene for human estrogen receptor positive (ER+) breast cancer and a cellular mechanosensor. Nup210 depletion suppresses lung metastasis in mouse models of breast cancer.

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Article Synopsis
  • Lynch syndrome (LS) is a hereditary cancer predisposition syndrome linked to harmful genetic variants in DNA mismatch repair (MMR) genes, with a specific variant prevalent in the Canadian Inuit population.
  • A common founder variant in the PMS2 gene causes both a benign missense change and a significant splicing defect, leading to a truncated protein and increased risk of cancer in homozygous individuals.
  • Researchers developed a mouse model with a similar genetic mutation, which shows similar splicing defects and several cancer characteristics, thus providing a useful tool for studying potential treatments for this condition, particularly in the Canadian Inuit community.
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The Immunodeficiency Centromeric Instability Facial Anomalies (ICF) 4 syndrome is caused by mutations in LSH/HELLS, a chromatin remodeler promoting incorporation of histone variant macroH2A. Here, we demonstrate that LSH depletion results in degradation of nascent DNA at stalled replication forks and the generation of genomic instability. The protection of stalled forks is mediated by macroH2A, whose knockdown mimics LSH depletion and whose overexpression rescues nascent DNA degradation.

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Background: Chromosomal inversions involving anaplastic lymphoma kinase (ALK) and echinoderm microtubule associated protein like 4 (EML4) generate a fusion protein EML4-ALK in non-small cell lung cancer (NSCLC). The understanding of EML4-ALK function can be improved by a functional study using normal human cells.

Methods: Here we for the first time conduct such study to examine the effects of EML4-ALK on cell proliferation, cellular senescence, DNA damage, gene expression profiles and transformed phenotypes.

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Article Synopsis
  • * A previous approach using Cas9 mRNA and an oligodeoxynucleotide donor had the potential to repair genetic mutations but wasn't efficient enough in inactive CD34+ hematopoietic cells for use in patients.
  • * This study found that temporarily blocking the protein 53BP1 boosted the efficiency of gene repair by 2.3 times, resulting in a successful correction in 80% of X-CGD CD34+ cells, offering a promising pathway for clinical treatment.
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Jacobsen syndrome (MIM #147791) is a rare multisystem genomic disorder involving craniofacial abnormalities, intellectual disability, other neurodevelopmental defects, and terminal truncation of chromosome 11q, typically deleting ~170 to >340 genes. We describe the first case of Jacobsen syndrome caused by congenital chromoanasynthesis, an extreme form of complex chromosomal rearrangement. Six duplications and five deletions occurred on one copy of chromosome 11q with microhomology signatures in the breakpoint junctions, indicating an all-at-once replication-based rearrangement mechanism in a gametocyte or early post-zygotic cell.

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Synthetic lethality between poly(ADP-ribose) polymerase (PARP) inhibition and deficiency is exploited to treat breast and ovarian tumors. However, resistance to PARP inhibitors (PARPis) is common. To identify potential resistance mechanisms, we performed a genome-wide RNAi screen in BRCA2-deficient mouse embryonic stem cells and validation in KB2P1.

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