Publications by authors named "John C Hancock"

Background: Gliosarcoma, an isocitrate dehydrogenase wildtype (IDH-WT) variant of glioblastoma, is defined by clonal biphasic differentiation into gliomatous and sarcomatous components. While the transformation from a glioblastoma to gliosarcoma is uncommon, the subsequent transformation to osteosarcoma is rare but may provide additional insights into the biology of these typically distinct cancers. We observed a patient initially diagnosed with glioblastoma, that differentiated into gliosarcoma at recurrence, and further evolved to osteosarcoma at the second relapse.

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Cancer stem cells are thought to be the main drivers of tumorigenesis for malignancies such as glioblastoma (GBM). They are maintained through a close relationship with the tumor vasculature. Previous literature has well-characterized the components and signaling pathways for maintenance of this stem cell niche, but details on how the niche initially forms are limited.

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Metabolic function plays a key role in immune cell activation, destruction of foreign pathogens, and memory cell generation. As T cells are activated, their metabolic profile is significantly changed due to signaling cascades mediated by the T cell receptor (TCR) and co-receptors found on their surface. CD5 is a T cell co-receptor that regulates thymocyte selection and peripheral T cell activation.

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The use of immunotherapies for the treatment of brain tumors is a topic that has garnered considerable excitement in recent years. Discoveries such as the presence of a glymphatic system and immune surveillance in the central nervous system (CNS) have shattered the theory of immune privilege and opened up the possibility of treating CNS malignancies with immunotherapies. However, despite many immunotherapy clinical trials aimed at treating glioblastoma (GBM), very few have demonstrated a significant survival benefit.

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CD4 T cells are crucial for effective repression and elimination of cancer cells. Despite a paucity of CD4 T cell receptor (TCR) clinical studies, CD4 T cells are primed to become important therapeutics as they help circumvent tumor antigen escape and guide multifactorial immune responses. However, because CD8 T cells directly kill tumor cells, most research has focused on the attributes of CD8 TCRs.

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The metastasis-associated protein 1(MTA1)/histone deacetylase (HDAC) unit is a cancer progression-related epigenetic regulator, which is overexpressed in hormone-refractory and metastatic prostate cancer (PCa). In our previous studies, we found a significantly increased MTA1 expression in a prostate-specific Pten-null mouse model. We also demonstrated that stilbenes, namely resveratrol and pterostilbene (Pter), affect MTA1/HDAC signaling, including deacetylation of tumor suppressors p53 and PTEN.

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We have previously shown that metastasis-associated protein 1 (MTA1), a chromatin remodeler, plays an important role in prostate cancer invasiveness, likely through regulation of epithelial-to-mesenchymal transition. Here, we identified miR-22 as an epigenetic-microRNA (Epi-miR) directly induced by MTA1 and predicted to target E-cadherin. Loss-of-function and overexpression studies of MTA1 reinforced its regulatory role in miR-22 expression.

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The present study was done to characterize the effects of endogenous tachykinins on heart rate in urethane-anesthetized guinea pigs. Intravenous injection of capsaicin (32 nmol/kg) was used to evoke release of tachykinins and calcitonin gene-related peptide (CGRP) from cardiac sensory nerve fibers. Such injections caused a brief decrease in heart rate (-37+/-7 beats/min, n=6) that was followed by a more prolonged increase (+44+/-10 beats/min).

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Effects of substance P (SP) and selective tachykinin agonists on neurotransmission at guinea-pig intracardiac ganglia were studied in vitro. Voltage responses of neurons to superfused tachykinins and nerve stimulation were measured using intracellular microelectrodes. Predominant effects of SP (1 microM) were to cause slow depolarization and enable synaptic transmission at low intensities of nerve stimulation.

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This study was done to determine if pituitary adenylate cyclase-activating peptide (PACAP)-immunoreactive nerve fibers occur in cardiac muscle as well as intracardiac ganglia of rats and guinea pigs and to clarify the chronotropic actions of PACAP27 in the same species using isolated heart preparations. PACAP nerve fibers were not detected in atrial or ventricular muscle of rat or guinea pig but a few stained nerve fibers occurred in the atrioventricular bundle of the guinea pig. Stained nerve fibers were prominent in intracardiac ganglia of both species.

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This study investigated the cellular basis for the enhanced ganglionic responsiveness to NK1 agonists in the spontaneously hypertensive rat (SHR) in comparison to their normotensive counterpart, the Wistar-Kyoto (WKY) rat. Rats for in vivo studies were anesthetized with pentobarbital and treated with chlorisondamine (10.5 micromol/kg).

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