Publications by authors named "William F Harrington"

Genetic and chemical perturbations impact diverse cellular phenotypes, including multiple indicators of cell health. These readouts reveal toxicity and antitumorigenic effects relevant to drug discovery and personalized medicine. We developed two customized microscopy assays, one using four targeted reagents and the other three targeted reagents, to collectively measure 70 specific cell health phenotypes including proliferation, apoptosis, reactive oxygen species, DNA damage, and cell cycle stage.

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The development of clinically viable delivery methods presents one of the greatest challenges in the therapeutic application of CRISPR/Cas9 mediated genome editing. Here, we report the development of a lipid nanoparticle (LNP)-mediated delivery system that, with a single administration, enabled significant editing of the mouse transthyretin (Ttr) gene in the liver, with a >97% reduction in serum protein levels that persisted for at least 12 months. These results were achieved with an LNP delivery system that was biodegradable and well tolerated.

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Article Synopsis
  • MYC transcription factors, such as MYCN, are challenging therapeutic targets in cancer, notably linked to high-risk neuroblastoma, which has poor outcomes.
  • Researchers used CRISPR-Cas9 screening to identify a key dependency on polycomb repressive complex 2 (PRC2) genes (EZH2, EED, SUZ12) in MYCN-amplified neuroblastoma, finding that EZH2 suppression inhibits tumor growth.
  • MYCN enhances EZH2 expression, which represses neuronal differentiation and tumor suppressor genes, suggesting that EZH2 inhibitors could be a promising treatment for patients with MYCN-amplified neuroblastoma, especially in combination with other therapies.
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The CRISPR-Cas9 system has revolutionized gene editing both at single genes and in multiplexed loss-of-function screens, thus enabling precise genome-scale identification of genes essential for proliferation and survival of cancer cells. However, previous studies have reported that a gene-independent antiproliferative effect of Cas9-mediated DNA cleavage confounds such measurement of genetic dependency, thereby leading to false-positive results in copy number-amplified regions. We developed CERES, a computational method to estimate gene-dependency levels from CRISPR-Cas9 essentiality screens while accounting for the copy number-specific effect.

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Most human epithelial tumors harbor numerous alterations, making it difficult to predict which genes are required for tumor survival. To systematically identify cancer dependencies, we analyzed 501 genome-scale loss-of-function screens performed in diverse human cancer cell lines. We developed DEMETER, an analytical framework that segregates on- from off-target effects of RNAi.

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Article Synopsis
  • The CRISPR/Cas9 system was used in a study involving 33 cancer cell lines to locate essential genes for cell growth and survival, revealing that increased gene copy number led to reduced cell viability when edited.
  • Targeting both expressed and unexpressed genes resulted in significant decreases in cell growth, causing G2 cell-cycle arrest, indicating a broader impact of CRISPR/Cas9 beyond specific gene edits.
  • The study emphasizes that the number of DNA breaks created by CRISPR/Cas9 triggers a gene-independent response, signaling a need for careful interpretation of screening data and potential new strategies for cancer treatment.
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Background: The authors have previously demonstrated that human herniated disc material contains high concentrations of free glutamate. In an experimental model, elevated epidural glutamate concentrations in the lumbar spine can cause a focal hyperesthetic state.

Methods: Rats underwent epidural glutamate infusion in the lumbar spine by a miniosmotic pump over a 72-hour period.

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Background Context: The authors have previously demonstrated that herniated human lumbar disc is rich in free glutamate from degradation of aggrecan. Prior data have suggested that free glutamate could contribute to a nociceptive state.

Purpose: Previous behavioral experiments suggested glutamate-related nociception by comparing pre- and postglutamate infusion responses only.

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