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"Freeman, Kevin"
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Loss of ARID1A leads to a cold tumor phenotype via suppression of IFNγ signaling
by
Freeman, Kevin W.
,
DeVaux, Chelsea A.
,
Watson, Pamela M.
in
631/67/2332
,
631/67/580
,
631/67/68/2486
2025
The collapse of inflammatory signaling that recruits cytotoxic immune cells to the tumor microenvironment contributes to the immunologically cold tumor phenotype in neuroblastoma (NB) and is a barrier to NB immunotherapy. Multiple studies have reported that
MYCN
amplification, a trait of high-risk NB, correlates with a loss of inflammatory signaling; but
MYCN
also correlates with 1p36 deletions in NB where the SWI/SNF chromatin remodeling complex subunit
ARID1A
(1p36.11) is located. ARID1A is known to support inflammatory signaling in adult cancers but its role in NB inflammatory signaling is unexplored. We find
MYCN
overexpression causes a stronger inflammatory response to interferon-gamma (IFNγ). ARID1A knockdown causes a weaker inflammatory response and reduces IFNγ induced gene signatures for the transcription factor interferon response factor 1 (
IRF1
). We found ARID1A is a functional interactor of IRF1 by co-immunoprecipitation studies, and ARID1A silencing causes loss of activating chromatin marks at the IRF1 target gene
CXCL10
. We model that IRF1 uses ARID1A containing SWI/SNF to promote CXCL10 in response to IFNγ. Our work clarifies that the loss of ARID1A, which tightly associates with
MYCN
amplification, causes reduced inflammatory signaling. This work finds that ARID1A is a critical regulator of inflammatory signaling in NB and provides rationale for testing immune therapies in
MYCN
amplified NB that are effective in adult ARID1A mutated cancers.
Journal Article
Transcription factor 4 is a key mediator of oncogenesis in neuroblastoma by promoting MYC activity
by
Freeman, Kevin W.
,
DeVaux, Chelsea
,
Olsen, Rachelle R.
in
Animals
,
Apoptosis
,
Basic Helix-Loop-Helix Leucine Zipper Transcription Factors - genetics
2025
Super‐enhancer‐associated transcription factor networks define cell identity in neuroblastoma (NB). Dysregulation of these transcription factors contributes to the initiation and maintenance of NB by enforcing early developmental identity states. We report that the class I basic helix–loop–helix (bHLH) transcription factor 4 (TCF4; also known as E2‐2) is a critical NB dependency gene that significantly contributes to these identity states through heterodimerization with cell‐identity‐specific bHLH transcription factors. Knockdown of TCF4 significantly induces apoptosis in vitro and inhibits tumorigenicity in vivo. We used genome‐wide expression profiling, TCF4 chromatin immunoprecipitation sequencing (ChIP‐seq) and TCF4 immunoprecipitation–mass spectrometry to determine the role of TCF4 in NB cells. Our results, along with recent findings in NB for the transcription factors T‐box transcription factor TBX2, heart‐ and neural crest derivatives‐expressed protein 2 (HAND2) and twist‐related protein 1 (TWIST1), propose a role for TCF4 in regulating forkhead box protein M1 (FOXM1)/transcription factor E2F‐driven gene regulatory networks that control cell cycle progression in cooperation with N‐myc proto‐oncogene protein (MYCN), TBX2, and the TCF4 dimerization partners HAND2 and TWIST1. Collectively, we showed that TCF4 promotes cell proliferation through direct transcriptional regulation of the c‐MYC/MYCN oncogenic program that drives high‐risk NB. Mechanistically, our data suggest the novel finding that TCF4 acts to support MYC activity by recruiting multiple factors known to regulate MYC function to sites of colocalization between critical NB transcription factors, TCF4 and MYC oncoproteins. Many of the TCF4‐recruited factors are druggable, giving insight into potential therapies for high‐risk NB. This study identifies a new function for class I bHLH transcription factors (e.g., TCF3, TCF4, and TCF12) that are important in cancer and development. Core regulatory circuitry (CRC) transcription factors (TFs), whose effects are increased by MYC, define cancer cell‐type identity and drive oncogenes in cancer. This study found that the TF TCF4 (E2‐2) heterodimerizes with key CRC TFs to recruit MYC cofactors that increase MYC DNA‐binding and activity. These findings better define the mechanistic relationship of CRC TFs with MYC.
Journal Article
Psychosis secondary to thyrotoxicosis that persisted post-thyroidectomy: a case report
2023
Background
This case report is of a patient with psychosis secondary to thyrotoxicosis that persisted and reemerged after definitive treatment of thyroidectomy, which is a unique occurrence in the literature.
Case presentation
This patient is a male between 30 and 35 years of age with a history of Graves Disease and no past psychiatric history who was admitted to the hospital due to psychosis secondary to thyrotoxicosis. The thyrotoxicosis was treated with surgical removal, but the psychotic symptoms persisted after surgery and normalization of standard thyroid functional measures. The symptoms were of sufficient significance for inpatient psychiatric hospitalization, a rare occurrence. Ultimately after an extended stay in the psychiatric unit, the patient’s symptoms stabilized with a second-generation antipsychotic, and the patient was discharged from the psychiatric unit.
Conclusion
This case is evidence that the link between psychosis and hyperthyroidism is still poorly understood due to the patient’s psychotic symptoms persisting after the definitive treatment of thyroidectomy and the fact that it required anti-psychotic medications for normalization.
Journal Article
The kappa-opioid receptor agonist, triazole 1.1, reduces oxycodone self-administration and enhances oxycodone-induced thermal antinociception in male rats
2021
RationaleTriazole 1.1 is a novel kappa-opioid receptor (KOR) agonist reported to produce antinociception without KOR-typical adverse effects. When combined with the mu-opioid receptor (MOR) agonist, oxycodone, triazole 1.1 blocks oxycodone-induced pruritis without producing sedation-like effects in nonhuman primates. However, it is unknown if triazole 1.1 can reduce the abuse-related effects or enhance the antinociceptive effects of oxycodone similarly to other KOR agonists.ObjectivesThe aim of the present study was to quantitatively compare the behavioral effects of triazole 1.1 to the KOR agonists, U50,488h and nalfurafine, on oxycodone self-administration and oxycodone-induced thermal antinociception when administered as mixtures with oxycodone.MethodsIn the self-administration study, male Sprague–Dawley (SD) rats (n = 6) self-administered intravenous (i.v.) oxycodone alone (0.056 mg/kg/inj) or combined with U50,488 h (0.032-0.32 mg/kg/inj), nalfurafine (0.00032–0.0032 mg/kg/inj), or triazole 1.1 (0.32–1.8 mg/kg/inj) under a progressive-ratio schedule of reinforcement. In a hot plate assay, male SD rats (n = 6) received i.v. injections of oxycodone (1.0-5.6 mg/kg), U50,488h (1.0-18.0 mg/kg), nalfurafine (0.01-1.0 mg/kg), or triazole 1.1 (3.2-32.0 mg/kg) alone or in combinations of fixed proportion with oxycodone based on the relative potencies of the single drugs. Each study concluded with administration of the KOR antagonist nor-BNI and some degree of retesting of the previous conditions to verify that the behavioral effects were mediated by KOR activation.ResultsAll KOR agonists reduced oxycodone self-administration in a dose-dependent manner. Moreover, all single drugs and drug combinations produced dose-dependent, fully efficacious thermal antinociception. All KOR agonist:oxycodone combinations produced either additive or super-additive thermal antinociception. Finally, each KOR agonist was blocked in effect by nor-BNI in both behavioral measures.ConclusionThis study demonstrates that triazole 1.1 reduces oxycodone’s reinforcing effects and enhances oxycodone-induced antinociception to degrees that are comparable to typical KOR agonists. Given triazole 1.1’s mild adverse-effect profile, developing MOR-KOR agonist combinations from the triazole 1.1 series may render new pain therapeutics with reduced abuse liability.
Journal Article
Kappa opioid agonists reduce oxycodone self-administration in male rhesus monkeys
2020
RationaleCombinations of mu and kappa opioid receptor (KOR) agonists have been proposed as potential analgesic formulations with reduced abuse liability. The current studies extend previous work by investigating the typical KOR agonist, salvinorin A, and the atypical KOR agonist, nalfurafine, as deterrents of oxycodone self-administration using a progressive ratio (PR) schedule of reinforcement.MethodsIn separate experiments, adult male rhesus monkeys (N = 4/experiment) were trained under a PR schedule of reinforcement to self-administer cocaine (0.1 mg/kg/injection) and saline on alternating days. Oxycodone (0.01–0.1 mg/kg/injection) alone and combined with salvinorin A (experiment 1; 0.006, 0.012 mg/kg/injection) or nalfurafine (experiment 2; 0.0001–0.00032 mg/kg/injection) were tested within the alternating cocaine and saline baseline. The mechanism of nalfurafine’s effects on oxycodone self-administration was investigated via pretreatment with the KOR antagonist, nor-binaltorphimine (nor-BNI; 10 mg/kg; i.m.).ResultsAll subjects self-administered oxycodone alone above saline levels at sufficiently large doses, and combining salvinorin A or nalfurafine with oxycodone reduced the mean number of injections per session to saline levels (experiment 1) or to levels that were significantly lower than oxycodone alone (experiment 2). The ability of nalfurafine to reduce oxycodone self-administration was reversed by pretreatment with nor-BNI.ConclusionsThese results demonstrate that KOR agonists, including the clinically used KOR agonist, nalfurafine, can punish self-administration of a prescription opioid analgesic, oxycodone, in rhesus monkeys and that nalfurafine’s punishing effect is KOR-dependent. Combinations of KOR agonists with prescription opioids may have reduced abuse liability.
Journal Article
Cross-Species evidence for hippocampal CACNA1C as a therapeutic target for alcohol use disorder
2026
Context-induced relapse is a major barrier to recovery from alcohol use disorder (AUD). Identifying molecular targets involved in contextual memories associated with alcohol use may serve as novel pharmacotherapies. Our RNAseq profiling study of the hippocampus from rhesus monkeys with chronic alcohol use identified the voltage-gated calcium channel CACNA1C as a promising therapeutic target. However, data regarding CACNA1C expression in AUD and whether inhibition of CACNA1C can attenuate ethanol contextual memories remains limited. We tested the hypothesis that hippocampal CACNA1C expression is increased in human and nonhuman primates (NHPs) with chronic alcohol use. Further, we used a mouse conditioned place preference (CPP) paradigm to test the hypothesis that Nifedipine, a CACNA1C-selective L-type calcium channel antagonist, can attenuate ethanol-induced CPP. CACNA1C mRNA expression was increased in the hippocampus of subjects with AUD (
p
< 0.03). Increased densities of CACNA1C neurons (
p
< 0.01) and glia (
p
< 0.02) were observed in rhesus monkeys with chronic alcohol use. Ethanol-treated mice spent more time in the ethanol-paired chamber compared to the vehicle animals (
p
< 0.04), demonstrating ethanol-induced CPP. This effect was attenuated by Nifedipine, as time spent in the ethanol-paired chamber in the ethanol + Nifedipine group was not significantly different from the vehicle group. These findings demonstrate that chronic alcohol use increases CACNA1C expression in the hippocampus across species and that a CACNA1C subtype-selective antagonist reduces ethanol-induced CPP. Together, these results support CACNA1C as a promising therapeutic target for memory dysfunction in AUD.
Journal Article
Contingent administration of typical and biased kappa opioid agonists reduces cocaine and oxycodone choice in a drug vs. food choice procedure in male rhesus monkeys
by
Huskinson, Sally L
,
Zamarripa, C. Austin
,
Townsend, E. Andrew
in
Agonists
,
Analgesics
,
Antifungal agents
2024
RationaleCombinations of mu and kappa-opioid receptor (KOR) agonists have been proposed as analgesic formulations with reduced abuse potential. The feasibility of this approach has been increased by the development of KOR agonists with biased signaling profiles that produce KOR-typical antinociception with fewer KOR-typical side effects.ObjectiveThe present study determined if the biased KOR agonists, nalfurafine and triazole 1.1, could reduce choice for oxycodone in rhesus monkeys as effectively as the typical KOR agonist, salvinorin A.MethodsAdult male rhesus monkeys (N = 5) responded under a concurrent schedule of food delivery and intravenous cocaine injections (0.018 mg/kg/injection). Once trained, cocaine (0.018 mg/kg/injection) or oxycodone (0.0056 mg/kg/injection) was tested alone or in combination with contingent injections of salvinorin A (0.1–3.2 µg/kg/injection), nalfurafine (0.0032–0.1 µg/kg/injection), triazole 1.1 (3.2–100.0 µg/kg/injection), or vehicle. In each condition, the cocaine or oxycodone dose, as well as the food amount, was held constant across choice components, while the dose of the KOR agonist was increased across choice components.ResultsCocaine and oxycodone were chosen over food on more than 80% of trials when administered alone or contingently with vehicle. When KOR agonists were administered contingently with either cocaine or oxycodone, drug choice decreased in a dose-dependent manner. Salvinorin A and triazole 1.1 decreased drug-reinforcer choice without altering total trials completed (i.e., choice allocation shifted to food), while nalfurafine dose dependently decreased total trials completed.ConclusionsThese results demonstrate that salvinorin A and triazole 1.1, but not nalfurafine, selectively reduce cocaine and oxycodone self-administration independent of nonspecific effects on behavior, suggesting that G-protein bias does not appear to be a moderating factor in this outcome. Triazole 1.1 represents an important prototypical compound for developing novel KOR agonists as deterrents for prescription opioid abuse.
Journal Article
Comparison of the reinforcing, antinociceptive, and respiratory depressant effects of prototypical and G-protein biased mu-opioid receptor agonists in male and female Sprague–Dawley rats
2024
RationaleG-protein biased mu-opioid receptor (MOR) agonists have been reported to exhibit superior therapeutic windows compared to prototypical MOR agonists when relating antinociception to respiratory depression. However, there is relatively little research on the abuse potential of G-protein biased MOR agonists in relation to other behavioral endpoints.ObjectivesThe aim of the present study was to quantitatively compare the reinforcing, antinociceptive, and respiratory-depressant effects of the prototypical MOR agonists, fentanyl and oxycodone, to the G-protein biased MOR agonists, SR14968 and SR17018, in male and female rats.MethodsIn the self-administration study, four separate groups of Sprague–Dawley (SD) rats self-administered intravenous (i.v.) fentanyl, oxycodone, SR14968, and SR17018 under a progressive-ratio schedule of reinforcement. Using a within-subjects design, separate cohorts of SD rats were tested with i.v. fentanyl, oxycodone, SR14968, and SR17018 using a hot-plate assay, assays of neuropathic and inflammatory antinociception, and whole-body plethysmography.ResultsAll MOR agonists functioned as reinforcers, but SR14968 and SR17018 were less efficacious relative to oxycodone and fentanyl. Moreover, all MOR agonists produced dose-dependent and fully efficacious antinociception across all nociception modalities. Oxycodone and fentanyl, but not SR14968 or SR17018, produced respiratory depression in a dose-dependent manner.ConclusionThe present results indicate that the G-protein biased MOR agonists tested herein produce MOR-typical antinociception, exhibit reduced but apparent abuse potential, and do not produce respiratory effects at doses that are above the antinociceptive range. Atypical MOR agonists within the SR series should be further studied as foundational molecules for the development of safter analgesics.
Journal Article
Effects of nalfurafine on the reinforcing, thermal antinociceptive, and respiratory-depressant effects of oxycodone: modeling an abuse-deterrent opioid analgesic in rats
by
McLendon, Hunter W.
,
Naylor, Jennifer E.
,
Freeman, Kevin B.
in
Abuse
,
Analgesics - pharmacology
,
Analgesics, Opioid - pharmacology
2017
Rationale
Strategies to reduce the misuse of mu opioid agonists are critically needed. Previous work has shown that kappa opioid agonists can diminish the abuse-related effects and augment the antinociceptive effects of mu agonists. However, use of traditional kappa agonists is limited by their dysphoric side effects.
Objectives
The current study examined the effects of nalfurafine, a clinically available atypical kappa agonist, on the reinforcing, thermal antinociceptive, and respiratory-depressant effects of oxycodone in male rats.
Methods
To determine oxycodone/nalfurafine mixture proportions to be examined intravenously across procedures, a progressive ratio (PR) self-administration procedure compared the reinforcing effects of oxycodone (56 μg/kg/inj) available alone or as a mixture with co-administered nalfurafine (0.32, 1, or 3.2 μg/kg/inj), corresponding to oxycodone/nalfurafine proportions of 175:1, 56:1, and 18:1, respectively. Next, PR and thermal antinociception dose-effect functions were each determined for oxycodone, nalfurafine, and the same oxycodone/nalfurafine mixture proportions. Finally, the respiratory-depressant effects of equi-antinociceptive doses of oxycodone, nalfurafine, and the mixtures were compared.
Results
Nalfurafine decreased the reinforcing effects of oxycodone, and the 18:1 mixture did not function as a reinforcer. Oxycodone and nalfurafine each produced dose-dependent antinociception, and the mixtures produced additive antinociception. In addition, antinociceptive doses of the 56:1 and 18:1 mixtures did not produce respiratory depression.
Conclusions
These results suggest that nalfurafine may augment the thermal antinociceptive effects while reducing the reinforcing and respiratory-depressant effects of oxycodone.
Journal Article
Antagonizing Bcl-2 Family Members Sensitizes Neuroblastoma and Ewing’s Sarcoma to an Inhibitor of Glutamine Metabolism
by
Freeman, Kevin W.
,
Yin, Zhirong
,
Olsen, Rachelle R.
in
Addictions
,
Amino acids
,
Aniline Compounds - administration & dosage
2015
Neuroblastomas (NBL) and Ewing's sarcomas (EWS) together cause 18% of all pediatric cancer deaths. Though there is growing interest in targeting the dysregulated metabolism of cancer as a therapeutic strategy, this approach has not been fully examined in NBL and EWS. In this study, we first tested a panel of metabolic inhibitors and identified the glutamine antagonist 6-diazo-5-oxo-L-norleucine (DON) as the most potent chemotherapeutic across all NBL and EWS cell lines tested. Myc, a master regulator of metabolism, is commonly overexpressed in both of these pediatric malignancies and recent studies have established that Myc causes cancer cells to become \"addicted\" to glutamine. We found DON strongly inhibited tumor growth of multiple tumor lines in mouse xenograft models. In vitro, inhibition of caspases partially reversed the effects of DON in high Myc expressing cell lines, but not in low Myc expressing lines. We further showed that induction of apoptosis by DON in Myc-overexpressing cancers is via the pro-apoptotic factor Bax. To relieve inhibition of Bax, we tested DON in combination with the Bcl-2 family antagonist navitoclax (ABT-263). In vitro, this combination caused an increase in DON activity across the entire panel of cell lines tested, with synergistic effects in two of the N-Myc amplified neuroblastoma cell lines. Our study supports targeting glutamine metabolism to treat Myc overexpressing cancers, such as NBL and EWS, particularly in combination with Bcl-2 family antagonists.
Journal Article