Publications by authors named "Brenda O'Connell"

Background: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with a poor prognosis particularly in the metastatic setting. Treatments with anti-programmed cell death protein-1/programmed death-ligand 1 (PD-L1) immune checkpoint inhibitors (ICI) in combination with chemotherapies have demonstrated promising clinical benefit in metastatic TNBC (mTNBC) but there is still an unmet need, particularly for patients with PD-L1 negative tumors. Mechanisms of resistance to ICIs in mTNBC include the presence of immunosuppressive tumor-associated macrophages (TAMs) in the tumor microenvironment (TME).

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Virulent infectious agents such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and methicillin-resistant (MRSA) induce tissue damage that recruits neutrophils, monocyte, and macrophages, leading to T cell exhaustion, fibrosis, vascular leak, epithelial cell depletion, and fatal organ damage. Neutrophils, monocytes, and macrophages recruited to pathogen-infected lungs, including SARS-CoV-2-infected lungs, express phosphatidylinositol 3-kinase gamma (PI3Kγ), a signaling protein that coordinates both granulocyte and monocyte trafficking to diseased tissues and immune-suppressive, profibrotic transcription in myeloid cells. PI3Kγ deletion and inhibition with the clinical PI3Kγ inhibitor eganelisib promoted survival in models of infectious diseases, including SARS-CoV-2 and MRSA, by suppressing inflammation, vascular leak, organ damage, and cytokine storm.

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Objective: This study examines the relationship between trait gratitude and acute myocardial infarction. A burgeoning body of literature suggests that gratitude can play a role in regulating individual's cardiovascular responses to stress which in turn, may reduce the incidence of cardiovascular disease such as acute myocardial infarction. However, to date no research has examined these effects.

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Purpose: Eganelisib (IPI-549) is a first-in-class, orally administered, highly selective PI3Kγ inhibitor with antitumor activity alone and in combination with programmed cell death protein 1/ligand 1 (PD-1/PD-L1) inhibitors in preclinical studies. This phase 1/1b first-in-human, MAcrophage Reprogramming in Immuno-Oncology-1 (NCT02637531) study evaluated the safety and tolerability of once-daily eganelisib as monotherapy and in combination with nivolumab in patients with solid tumors.

Patients And Methods: Dose-escalation cohorts received eganelisib 10-60 mg as monotherapy (n = 39) and 20-40 mg when combined with nivolumab (n = 180).

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Previous research has indicated that gratitude and affect-balance play key stress-buffering roles. However, to date there is limited research on the impact of gratitude and affect balance on cardiovascular recovery from acute psychological stress, and whether affect balance moderates the relationship between gratitude and cardiovascular reactions to acute psychological stress. In this study, 68 adults completed measures of state gratitude, positive and negative affect, and completed a laboratory-based cardiovascular stress-testing protocol.

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There is increasing appreciation that group memberships can have both beneficial and damaging impacts on health. In collaboration with Nepal Leprosy Trust (NLT), this longitudinal study explores a group-based approach to stigma reduction among people affected by leprosy in rural Nepal (N = 71)-a hard to reach and underrepresented non-WEIRD population. Informed by the 'social cure' literature, and the progressive model of self-stigma, we use a longitudinal design.

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The Building Resources in Caregivers (BRiC) is a pilot feasibility trial that compared the effects of a 2-week benefit finding writing expressive intervention to a control intervention, who wrote about the weather. Caregivers completed primary (benefit finding) and secondary (quality of life, depression and anxiety) outcome measures at pre (t1), immediately post-test (t2) and 1 month later (t3). They also completed measures relating to trial feasibility, difficulty, and acceptance.

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There is now a growing body of research demonstrating the physical health benefits of being grateful. However, research has only just began to explore the mechanisms accounting for this gratitude-health relationship. This study examines the relationship between dispositional gratitude and self-reported physical health symptoms, and explores whether this relationship is explained through reduced levels of perceived loneliness and stress.

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Objective: This study examined the effect of a reflective interpersonal gratitude journal, a reflective-behavioral interpersonal gratitude journal and an active control journal, on primary qualities of well-being and depression.

Method: Participants (n = 192; 67.2% female) completed this 3-month longitudinal randomized controlled design.

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Caregivers may engage in benefit finding, that is, an increase in perceived positive growth, as a cognitive strategy for coping with stress. The Building Resources in Caregivers study will compare effects of a brief benefit finding writing intervention with a control intervention. Caregivers of people with mental and physical disabilities will be randomised into either a benefit-writing group or a neutral writing group.

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HSP90 inhibitors are currently undergoing clinical evaluation in combination with antimitotic drugs in non-small cell lung cancer (NSCLC), but little is known about the cellular effects of this novel drug combination. Therefore, we investigated the molecular mechanism of action of IPI-504 (retaspimycin HCl), a potent and selective inhibitor of HSP90, in combination with the microtubule targeting agent (MTA) docetaxel, in preclinical models of NSCLC. We identified a subset of NSCLC cell lines in which these drugs act in synergy to enhance cell death.

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The elaboration of dendrites in neurons requires secretory trafficking through the Golgi apparatus, but the mechanisms that govern Golgi function in neuronal morphogenesis in the brain have remained largely unexplored. Here, we report that the E3 ubiquitin ligase Cul7(Fbxw8) localizes to the Golgi complex in mammalian brain neurons. Inhibition of Cul7(Fbxw8) by independent approaches including Fbxw8 knockdown reveals that Cul7(Fbxw8) is selectively required for the growth and elaboration of dendrites but not axons in primary neurons and in the developing rat cerebellum in vivo.

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Replication stress involving collision of replisomes with camptothecin (CPT)-stabilized DNA-Topoisomerase I adducts activates an ATR-dependent pathway to promote repair by homologous recombination. To identify human genes that protect cells from such replication stress, we performed a genome-wide CPT sensitivity screen. Among numerous candidate genes are two previously unstudied proteins: the ankyrin repeat protein NFKBIL2 and C6ORF167 (MMS22L), distantly related to yeast replication stress regulator Mms22p.

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Structure-specific endonucleases mediate cleavage of DNA structures formed during repair of collapsed replication forks and double-strand breaks (DSBs). Here, we identify BTBD12 as the human ortholog of the budding yeast DNA repair factor Slx4p and D. melanogaster MUS312.

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Inhibition of differentiation has been proposed as an important mechanism for Myc-induced tumorigenesis, but the mechanisms involved are unclear. We have established a genetically defined differentiation model in human leukemia K562 cells by conditional expression of the cyclin-dependent kinase (Cdk) inhibitor p27 (inducible by Zn(2+)) and Myc (activatable by 4-hydroxy-tamoxifen). Induction of p27 resulted in erythroid differentiation, accompanied by Cdk inhibition and G(1) arrest.

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Cul4-Ddb1, a RING H2 ubiquitin ligase, plays an important role in many vital cellular processes including DNA replication, DNA repair and transcription. Recent research reveals strong links between Cul4-mediated signaling pathways and chromatin biology. Ubiquitylation of substrates by Cul4-Ddb1 occurs on chromatin and is initiated by chromatin-based signals that either recruit Cul4-Ddb1 to chromatin or alter the activity of the ligase.

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Definitive localization of c-Myc within the nucleus is important to fully understand the regulation and function of this oncoprotein. Studies of c-Myc distribution, however, have produced conflicting results. To overcome technical challenges inherent in c-Myc cytology, we use here three methods to visualize c-Myc and in addition examine the impact of proteasome inhibition.

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The myc proto-oncogenes encode transcriptional regulators whose inappropriate expression is correlated with a wide array of human malignancies. Up-regulation of Myc enforces growth, antagonizes cell cycle withdrawal and differentiation, and in some situations promotes apoptosis. How these phenotypes are elicited is not well understood, largely because we lack a clear picture of the biologically relevant downstream effectors.

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A cDNA library enriched with Myc-responsive cDNAs but depleted of myc cDNAs was used in a functional screen for growth enhancement in c-myc-null cells. A cDNA clone for mitochondrial serine hydroxymethyltransferase (mSHMT) that was capable of partial complementation of the growth defects of c-myc-null cells was identified. Expression analysis and chromatin immunoprecipitation demonstrated that mSHMT is a direct Myc target gene.

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