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result(s) for
"Jameson, Nathan"
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PTEN regulates glioblastoma oncogenesis through chromatin-associated complexes of DAXX and histone H3.3
2017
Glioblastoma (GBM) is the most lethal type of human brain cancer, where deletions and mutations in the tumour suppressor gene
PTEN
(phosphatase and tensin homolog) are frequent events and are associated with therapeutic resistance. Herein, we report a novel chromatin-associated function of PTEN in complex with the histone chaperone DAXX and the histone variant H3.3. We show that PTEN interacts with DAXX and, in turn PTEN directly regulates oncogene expression by modulating DAXX-H3.3 association on the chromatin, independently of PTEN enzymatic activity. Furthermore,
DAXX
inhibition specifically suppresses tumour growth and improves the survival of orthotopically engrafted mice implanted with human PTEN-deficient glioma samples, associated with global H3.3 genomic distribution changes leading to upregulation of tumour suppressor genes and downregulation of oncogenes. Moreover,
DAXX
expression anti-correlates with
PTEN
expression in GBM patient samples. Since loss of chromosome 10 and
PTEN
are common events in cancer, this synthetic growth defect mediated by
DAXX
suppression represents a therapeutic opportunity to inhibit tumorigenesis specifically in the context of PTEN deletion.
PTEN
mutations are frequent in glioblastoma and often are associated with therapeutic resistance. Here, the authors demonstrate that PTEN regulates gene expression at the chromatin level by interacting with the histone chaperone DAXX and H3.3, and that
DAXX
inhibition inhibits
PTEN
-deficient GBM growth
in vivo
.
Journal Article
Cyclin E1/CDK2 activation defines a key vulnerability to WEE1 kinase inhibition in gynecological cancers
by
Ma, Jianhui
,
Harford, Laurie
,
Charles, Vincent J.
in
631/154/53/2423
,
631/67/1059/602
,
Cancer Research
2025
Upregulation of Cyclin E1 and subsequent activation of CDK2 accelerates cell cycle progression from G1 to S phase and is a common oncogenic driver in gynecological malignancies. WEE1 kinase counteracts the effects of Cyclin E1/CDK2 activation by regulating multiple cell cycle checkpoints. Here we characterized the relationship between Cyclin E1/CDK2 activation and sensitivity to the selective WEE1 inhibitor azenosertib. We found that ovarian cancer cell lines with high levels of endogenous Cyclin E1 expression or forced overexpression were exquisitely sensitive to azenosertib and these results extended to in vivo models of ovarian and uterine serous carcinoma. Models with high Cyclin E1 expression showed higher baseline levels of replication stress and enhanced cellular responses to azenosertib treatment. We found azenosertib synergized with different classes of chemotherapy and described distinct underlying mechanisms. Finally, we provided early evidence from an ongoing phase I study demonstrating the clinical activity of monotherapy azenosertib in patients with Cyclin E1/CDK2-activated ovarian and uterine serous carcinomas.
Journal Article
Publisher Correction: PTEN regulates glioblastoma oncogenesis through chromatin-associated complexes of DAXX and histone H3.3
2018
This corrects the article DOI: 10.1038/ncomms15223.
Journal Article
Correction: Publisher Correction: PTEN regulates glioblastoma oncogenesis through chromatin-associated complexes of DAXX and histone H3.3
2018
Nature Communications 8:15223 doi: (2017); Published 12 May 2017; Updated 25 May 2018 The originally published version of this Article contained an error in Fig. 1. In panel d, the uppermost western blot was inadvertently inverted during typesetting of the figure. This has now been corrected in boththe PDF and HTML versions of the Article.
Journal Article
Circular ecDNA promotes accessible chromatin and high oncogene expression
2019
Oncogenes are commonly amplified on particles of extrachromosomal DNA (ecDNA) in cancer
1
,
2
, but our understanding of the structure of ecDNA and its effect on gene regulation is limited. Here, by integrating ultrastructural imaging, long-range optical mapping and computational analysis of whole-genome sequencing, we demonstrate the structure of circular ecDNA. Pan-cancer analyses reveal that oncogenes encoded on ecDNA are among the most highly expressed genes in the transcriptome of the tumours, linking increased copy number with high transcription levels. Quantitative assessment of the chromatin state reveals that although ecDNA is packaged into chromatin with intact domain structure, it lacks higher-order compaction that is typical of chromosomes and displays significantly enhanced chromatin accessibility. Furthermore, ecDNA is shown to have a significantly greater number of ultra-long-range interactions with active chromatin, which provides insight into how the structure of circular ecDNA affects oncogene function, and connects ecDNA biology with modern cancer genomics and epigenetics.
Imaging and sequencing approaches are combined to show that extrachromosomal DNA (ecDNA) in cancer is circular and has unique chromatin structure that amplifies oncogene output.
Journal Article
Bach and the Beauty of Christ: A Study in Theological Aesthetics
2020
This dissertation attempts to shed explanatory light on the work of Johann Sebastian Bach by situating it within the broader framework of Lutheran theological aesthetics. Although Bach has long been considered one of the most influential musicians in European history, he wrote very little about himself and the personal convictions that inspired his music. This vacuum has prompted theologians and musicologists to explore – and speculate about – the nature of those convictions and the historical sources that shaped them. Here I argue that Bach was a sophisticated interpreter of Lutheran aesthetics, who used music to make the beauty of Christ’s cosmic redemption more audible to his listeners.In order to defend this thesis, I adopt the following methodology: in chapter one, I present a conception of Bachian aesthetics from both theoretical and practical perspectives. In chapter two, I open up a historical vantage point for understanding that aesthetic conception: the thought of Martin Luther and his followers. Although Luther has typically been considered an anti-aesthetic figure, I follow the recent Luther scholarship of Mark C. Mattes and Miikka E. Anttila, who argue that Luther held to a radically Christocentric conception of beauty. After presenting my condensed rendering of Lutheran aesthetics, in chapter three I seek to situate music within that theo-dramatic framework. For Luther, music is one of the most beautiful gifts of God, which was created through Christ and can help Christians gain a foretaste of the heavenly beauty achieved by Christ’s crucifixion. In chapter four, then, I re-read chapter one in light of chapters two and three, with the goal of presenting Bach as a sophisticated interpreter of Lutheran aesthetics. In chapter five, I pivot to consider the implications of this study for the modern academy and church, two locales that are critical for both Bach and this dissertation. In particular, I suggest that neither the modern academy nor the modern church offer an entirely hospitable locale for studying and understanding Bach’s music. The dissertation closes by offering several alternative cultural locales for understanding Bachian aesthetics, to which both the contemporary academy and church should pay more attention.
Dissertation
Intron 1-Mediated Regulation of EGFR Expression in EGFR-dependent Malignancies
2019
The epidermal growth factor receptor is known to be overexpressed in numerous solid tumor types and has been the subject of extensive therapeutic development efforts. Much of the research on EGFR is focused on protein dynamics and downstream signaling, however few studies have explored how the gene is regulated transcriptionally. Here, we identified two novel enhancers (CE1 and CE2) present within the first intron of the EGFR gene in models of glioblastoma (GBM) and head and neck squamous cell carcinoma (HNSCC). CE1 and CE2 contain open chromatin and H3K27Ac histone marks, functionally enhance transcription in reporter assays, and interact with the EGFR promoter. Genetic deletion of CE1 and CE2 by CRISPR/Cas9 editing significantly reduces EGFR transcript levels, with double deletion exercising an additive effect. Similarly, targeted repression of CE1 and CE2 by dCas9-KRAB targeting demonstrates repression of transcription similar to that of genomic deletion. We identify AP-1 transcription factor family members in concert with BET bromodomain proteins as candidate modulators of CE1 and CE2 activity in HNSCC and GBM through de novo motif identification and validate their presence in these enhancers. Genetic inhibition of AP-1 or pharmacologic disruption of BET/AP-1 binding results in downregulated EGFR protein and transcript levels, further confirming a role for these factors in CE1 and CE2. Our results identify and characterize these novel enhancers, shedding light on the role that epigenetic mechanisms play in regulating EGFR transcription in EGFR-dependent cancer types.
Dissertation
Severe COVID-19 infection: An institutional review and literature overview
by
Mirza, Wasique
,
Akpoviroro, Ogheneyoma
,
Akpoviroro, Oghenetejiro Princess
in
Aged
,
Biology and Life Sciences
,
Body mass index
2024
Our study aimed to describe the group of severe COVID-19 patients at an institutional level, and determine factors associated with different outcomes.
A retrospective chart review of patients admitted with severe acute hypoxic respiratory failure due to COVID-19 infection. Based on outcomes, we categorized 3 groups of severe COVID-19: (1) Favorable outcome: progressive care unit admission and discharge (2) Intermediate outcome: ICU care (3) Poor outcome: in-hospital mortality.
Eighty-nine patients met our inclusion criteria; 42.7% were female. The average age was 59.7 (standard deviation (SD):13.7). Most of the population were Caucasian (95.5%) and non-Hispanic (91.0%). Age, sex, race, and ethnicity were similar between outcome groups. Medicare and Medicaid patients accounted for 62.9%. The average BMI was 33.5 (SD:8.2). Moderate comorbidity was observed, with an average Charlson Comorbidity index (CCI) of 3.8 (SD:2.6). There were no differences in the average CCI between groups(p = 0.291). Many patients (67.4%) had hypertension, diabetes (42.7%) and chronic lung disease (32.6%). A statistical difference was found when chronic lung disease was evaluated; p = 0.002. The prevalence of chronic lung disease was 19.6%, 27.8%, and 40% in the favorable, intermediate, and poor outcome groups, respectively. Smoking history was associated with poor outcomes (p = 0.04). Only 7.9% were fully vaccinated. Almost half (46.1%) were intubated and mechanically ventilated. Patients spent an average of 12.1 days ventilated (SD:8.5), with an average of 6.0 days from admission to ventilation (SD:5.1). The intermediate group had a shorter average interval from admission to ventilator (77.2 hours, SD:67.6), than the poor group (212.8 hours, SD:126.8); (p = 0.001). The presence of bacterial pneumonia was greatest in the intermediate group (72.2%), compared to the favorable group (17.4%), and the poor group (56%); this was significant (p<0.0001). In-hospital mortality was seen in 28.1%.
Most patients were male, obese, had moderate-level comorbidity, a history of tobacco abuse, and government-funded insurance. Nearly 50% required mechanical ventilation, and about 28% died during hospitalization. Bacterial pneumonia was most prevalent in intubated groups. Patients who were intubated with a good outcome were intubated earlier during their hospital course, with an average difference of 135.6 hours. A history of cigarette smoking and chronic lung disease were associated with poor outcomes.
Journal Article
Dynamic remodeling of a basolateral-to-central amygdala glutamatergic circuit across fear states
2019
Acquisition and extinction of learned fear responses utilize conserved but flexible neural circuits. Here we show that acquisition of conditioned freezing behavior is associated with dynamic remodeling of relative excitatory drive from the basolateral amygdala (BLA) away from corticotropin releasing factor-expressing (CRF+) centrolateral amygdala neurons, and toward non-CRF+ (CRF−) and somatostatin-expressing (SOM+) neurons, while fear extinction training remodels this circuit back toward favoring CRF+ neurons. Importantly, BLA activity is required for this experience-dependent remodeling, while directed inhibition of the BLA–centrolateral amygdala circuit impairs both fear memory acquisition and extinction memory retrieval. Additionally, ectopic excitation of CRF+ neurons impairs fear memory acquisition and facilities extinction, whereas CRF+ neuron inhibition impairs extinction memory retrieval, supporting the notion that CRF+ neurons serve to inhibit learned freezing behavior. These data suggest that afferent-specific dynamic remodeling of relative excitatory drive to functionally distinct subcortical neuronal output populations represents an important mechanism underlying experience-dependent modification of behavioral selection.
Journal Article
Multiphoton imaging of neural structure and activity in Drosophila through the intact cuticle
by
Mok, Aaron T
,
Shea, Jamien
,
Aragon, Max Jameson
in
Adipose tissues
,
Animal Scales - physiology
,
Animals
2022
We developed a multiphoton imaging method to capture neural structure and activity in behaving flies through the intact cuticle. Our measurements showed that the fly head cuticle has surprisingly high transmission at wavelengths >900nm, and the difficulty of through-cuticle imaging is due to the air sacs and/or fat tissue underneath the head cuticle. By compressing or removing the air sacs, we performed multiphoton imaging of the fly brain through the intact cuticle. Our anatomical and functional imaging results show that 2- and 3-photon imaging are comparable in superficial regions such as the mushroom body, but 3-photon imaging is superior in deeper regions such as the central complex and beyond. We further demonstrated 2-photon through-cuticle functional imaging of odor-evoked calcium responses from the mushroom body γ-lobes in behaving flies short term and long term. The through-cuticle imaging method developed here extends the time limits of in vivo imaging in flies and opens new ways to capture neural structure and activity from the fly brain.
Journal Article