Publications by authors named "Amanda R Haltom"

Dysregulated Myc signaling is a key oncogenic pathway in glioblastoma multiforme (GBM). Yet, effective therapeutic targeting of Myc continues to be challenging. Here, we demonstrate that exosomes generated from human bone marrow mesenchymal stem cells (MSCs) engineered to encapsulate siRNAs targeting Myc (iExo-Myc) localize to orthotopic GBM tumors in mice.

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Expression of the RE1-silencing transcription factor (REST), a master regulator of neurogenesis, is elevated in medulloblastoma (MB) tumors. A cell-intrinsic function for REST in MB tumorigenesis is known. However, a role for REST in the regulation of MB tumor microenvironment has not been investigated.

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Introduction: In the last decade, a number of genomic and pharmacological studies have demonstrated the importance of epigenetic dysregulation in medulloblastoma initiation and progression. High throughput approaches including gene expression array, next-generation sequencing (NGS), and methylation profiling have now clearly identified at least four molecular subgroups within medulloblastoma, each with distinct clinical and prognostic characteristics. These studies have clearly shown that despite the overall paucity of mutations, clinically relevant events do occur within the cellular epigenetic machinery.

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Article Synopsis
  • The study focuses on medulloblastomas (MBs) driven by the sonic hedgehog (SHH) pathway, highlighting the increased expression of the RE1-silencing transcription factor (REST) in the SHH-α and SHH-β subgroups, which are associated with poor patient outcomes.
  • Using a transgenic mouse model, researchers found that REST interacts with GLI1, impacting tumor growth and neuronal maturation, notably showing a greater neuronal maturity in SHH-β tumors.
  • Results indicate that REST contributes to chromatin remodeling and AKT activation in MBs, suggesting potential subgroup-specific therapeutic strategies for treating patients with these tumors.
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Pancreatic cancer presents with a dismal mortality rate and is in urgent need of methods for early detection with potential for timely intervention. All living cells, including cancer cells, generate exosomes. We previously discovered double stranded genomic DNA in exosomes derived from the circulation of pancreatic cancer patients, which enabled the detection of prevalent mutations associated with the disease.

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The epidermal growth factor (EGF)-like repeat is a common, evolutionarily conserved motif found in secreted proteins and the extracellular domain of transmembrane proteins. EGF repeats harbor six cysteine residues which form three disulfide bonds and help generate the three-dimensional structure of the EGF repeat. A subset of EGF repeats harbor consensus sequences for the addition of one or more specific O-glycans, which are initiated by O-glucose, O-fucose or O-N-acetylglucosamine.

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The protein O-glucosyltransferase Rumi/POGLUT1 regulates Drosophila Notch signaling by adding O-glucose residues to the Notch extracellular domain. Rumi has other predicted targets including Crumbs (Crb) and Eyes shut (Eys), both of which are involved in photoreceptor development. However, whether Rumi is required for the function of Crb and Eys remains unknown.

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