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Lomeli N, Pearre DC, Cruz M, Di K, Ricks-Oddie JL, Bota DA. Cisplatin induces BDNF downregulation in middle-aged female rat model while BDNF enhancement attenuates cisplatin neurotoxicity. Exp Neurol 2024; 375:114717. [PMID: 38336286 PMCID: PMC11087041 DOI: 10.1016/j.expneurol.2024.114717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 01/04/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024]
Abstract
Cancer-related cognitive impairments (CRCI) are neurological complications associated with cancer treatment, and greatly affect cancer survivors' quality of life. Brain-derived neurotrophic factor (BDNF) plays an essential role in neurogenesis, learning and memory. The reduction of BDNF is associated with the decrease in cognitive function in various neurological disorders. Few pre-clinical studies have reported on the effects of chemotherapy and medical stress on BDNF levels and cognition. The present study aimed to compare the effects of medical stress and cisplatin on serum BDNF levels and cognitive function in 9-month-old female Sprague Dawley rats to age-matched controls. Serum BDNF levels were collected longitudinally during cisplatin treatment, and cognitive function was assessed by novel object recognition (NOR) 14 weeks post-cisplatin initiation. Terminal BDNF levels were collected 24 weeks after cisplatin initiation. In cultured hippocampal neurons, we screened three neuroprotective agents, riluzole (an approved treatment for amyotrophic lateral sclerosis), as well as the ampakines CX546 and CX1739. We assessed dendritic arborization by Sholl analysis and dendritic spine density by quantifying postsynaptic density-95 (PSD-95) puncta. Cisplatin and exposure to medical stress reduced serum BDNF levels and impaired object discrimination in NOR compared to age-matched controls. Pharmacological BDNF augmentation protected neurons against cisplatin-induced reductions in dendritic branching and PSD-95. Ampakines (CX546 and CX1739) and riluzole did not affect the antitumor efficacy of cisplatin in vitro. In conclusion, we established the first middle-aged rat model of cisplatin-induced CRCI, assessing the contribution of medical stress and longitudinal changes in BDNF levels on cognitive function, although future studies are warranted to assess the efficacy of BDNF enhancement in vivo on synaptic plasticity. Collectively, our results indicate that cancer treatment exerts long-lasting changes in BDNF levels, and support BDNF enhancement as a potential preventative approach to target CRCI with therapeutics that are FDA approved and/or in clinical study for other indications.
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Affiliation(s)
- Naomi Lomeli
- Department of Neurology, University of California Irvine, Irvine, CA, USA
| | - Diana C Pearre
- Gynecologic Oncology, Providence Specialty Medical Group, Burbank, CA, USA
| | - Maureen Cruz
- Department of Neurology, University of California Irvine, Irvine, CA, USA
| | - Kaijun Di
- Department of Neurology, University of California Irvine, Irvine, CA, USA
| | - Joni L Ricks-Oddie
- Center for Statistical Consulting, Department of Statistics, University of California Irvine, Irvine, CA, USA; Biostatistics, Epidemiology and Research Design Unit, Institute for Clinical and Translational Sciences, University of California Irvine, Irvine, CA, USA
| | - Daniela A Bota
- Department of Neurology, University of California Irvine, Irvine, CA, USA; Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, CA, USA.
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Scaramuzza L, De Rocco G, Desiato G, Cobolli Gigli C, Chiacchiaretta M, Mirabella F, Pozzi D, De Simone M, Conforti P, Pagani M, Benfenati F, Cesca F, Bedogni F, Landsberger N. The enhancement of activity rescues the establishment of Mecp2 null neuronal phenotypes. EMBO Mol Med 2021; 13:e12433. [PMID: 33665914 PMCID: PMC8033520 DOI: 10.15252/emmm.202012433] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 01/24/2021] [Accepted: 01/27/2021] [Indexed: 01/29/2023] Open
Abstract
MECP2 mutations cause Rett syndrome (RTT), a severe and progressive neurodevelopmental disorder mainly affecting females. Although RTT patients exhibit delayed onset of symptoms, several evidences demonstrate that MeCP2 deficiency alters early development of the brain. Indeed, during early maturation, Mecp2 null cortical neurons display widespread transcriptional changes, reduced activity, and defective morphology. It has been proposed that during brain development these elements are linked in a feed-forward cycle where neuronal activity drives transcriptional and morphological changes that further increase network maturity. We hypothesized that the enhancement of neuronal activity during early maturation might prevent the onset of RTT-typical molecular and cellular phenotypes. Accordingly, we show that the enhancement of excitability, obtained by adding to neuronal cultures Ampakine CX546, rescues transcription of several genes, neuronal morphology, and responsiveness to stimuli. Greater effects are achieved in response to earlier treatments. In vivo, short and early administration of CX546 to Mecp2 null mice prolongs lifespan, delays the disease progression, and rescues motor abilities and spatial memory, thus confirming the value for RTT of an early restoration of neuronal activity.
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Affiliation(s)
- Linda Scaramuzza
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Present address:
Department of Bioscience, University of Milan, Milan, Italy; Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
| | - Giuseppina De Rocco
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
| | - Genni Desiato
- IRCCS Humanitas Research HospitalMilanItaly
- CNR Institute of NeuroscienceMilanItaly
| | - Clementina Cobolli Gigli
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Present address:
Francis Crick InstituteLondonUK
| | - Martina Chiacchiaretta
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
- Present address:
Department of NeuroscienceTufts University School of MedicineBostonMAUSA
| | - Filippo Mirabella
- IRCCS Humanitas Research HospitalMilanItaly
- Department of Biomedical Sciences, Humanitas UniversityMilanItaly
| | - Davide Pozzi
- IRCCS Humanitas Research HospitalMilanItaly
- Department of Biomedical Sciences, Humanitas UniversityMilanItaly
| | - Marco De Simone
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
- Present address:
Department of Radiation Oncology, Cedars-Sinai Medical CenterLos Angeles, CAUSA
| | - Paola Conforti
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
- Department of BiosciencesUniversity of MilanMilanItaly
| | - Massimiliano Pagani
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
- Istituto Nazionale Genetica Molecolare “Romeo ed Enrica Invernizzi”MilanItaly
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
- IRCCS Ospedale Policlinico San MartinoGenovaItaly
- Present address:
Francis Crick InstituteLondonUK
| | - Fabrizia Cesca
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di TecnologiaGenovaItaly
- Department of Life SciencesUniversity of TriesteTriesteItaly
- Present address:
Department of Radiation Oncology, Cedars-Sinai Medical CenterLos Angeles, CAUSA
| | - Francesco Bedogni
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Present address:
Neuroscience and Mental Health Research Institute (NMHRI)Division of NeuroscienceSchool of BiosciencesCardiffUK
| | - Nicoletta Landsberger
- Division of NeuroscienceIRCCS San Raffaele Scientific InstituteMilanItaly
- Department of Medical Biotechnology and Translational MedicineUniversity of MilanMilanItaly
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Wollman LB, Streeter KA, Fusco AF, Gonzalez-Rothi EJ, Sandhu MS, Greer JJ, Fuller DD. Ampakines stimulate phrenic motor output after cervical spinal cord injury. Exp Neurol 2020; 334:113465. [PMID: 32949571 DOI: 10.1016/j.expneurol.2020.113465] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 08/31/2020] [Accepted: 09/14/2020] [Indexed: 12/21/2022]
Abstract
Activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors increases phrenic motor output. Ampakines are a class of drugs that are positive allosteric modulators of AMPA receptors. We hypothesized that 1) ampakines can stimulate phrenic activity after incomplete cervical spinal cord injury (SCI), and 2) pairing ampakines with brief hypoxia could enable sustained facilitation of phrenic bursting. Phrenic activity was recorded ipsilateral (IL) and contralateral (CL) to C2 spinal cord hemisection (C2Hx) in anesthetized adult rats. Two weeks after C2Hx, ampakine CX717 (15 mg/kg, i.v.) increased IL (61 ± 46% baseline, BL) and CL burst amplitude (47 ± 26%BL) in 8 of 8 rats. After 90 min, IL and CL bursting remained above baseline (BL) in 7 of 8 rats. Pairing ampakine with a single bout of acute hypoxia (5-min, arterial partial pressure of O2 ~ 50 mmHg) had a variable impact on phrenic bursting, with some rats showing a large facilitation that exceeded the response of the ampakine alone group. At 8 weeks post-C2Hx, 7 of 8 rats increased IL (115 ± 117%BL) and CL burst amplitude (45 ± 27%BL) after ampakine. The IL burst amplitude remained above BL for 90-min in 7 of 8 rats; CL bursting remained elevated in 6 of 8 rats. The sustained impact of ampakine at 8 weeks was not enhanced by hypoxia exposure. Intravenous vehicle (10% 2-Hydroxypropyl-β-cyclodextrin) did not increase phrenic bursting at either time point. We conclude that ampakines effectively stimulate neural drive to the diaphragm after cervical SCI. Pairing ampakines with a single hypoxic exposure did not consistently enhance phrenic motor facilitation.
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Affiliation(s)
- L B Wollman
- Department of Physical Therapy, University of Florida, Gainesville, FL 32610, United States of America; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL 32610, United States of America
| | - K A Streeter
- Department of Physical Therapy, University of Florida, Gainesville, FL 32610, United States of America; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL 32610, United States of America
| | - A F Fusco
- Department of Physical Therapy, University of Florida, Gainesville, FL 32610, United States of America
| | - E J Gonzalez-Rothi
- Department of Physical Therapy, University of Florida, Gainesville, FL 32610, United States of America; McKnight Brain Institute, University of Florida, Gainesville, Florida 32610, United States of America; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL 32610, United States of America
| | - M S Sandhu
- Department of Physical Therapy, University of Florida, Gainesville, FL 32610, United States of America
| | - J J Greer
- Department of Physiology, University of Alberta, Edmonton, AB T6G2SE, Canada
| | - D D Fuller
- Department of Physical Therapy, University of Florida, Gainesville, FL 32610, United States of America; McKnight Brain Institute, University of Florida, Gainesville, Florida 32610, United States of America; Breathing Research and Therapeutics Center, University of Florida, Gainesville, FL 32610, United States of America.
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Seese RR, Le AA, Wang K, Cox CD, Lynch G, Gall CM. A TrkB agonist and ampakine rescue synaptic plasticity and multiple forms of memory in a mouse model of intellectual disability. Neurobiol Dis 2020; 134:104604. [PMID: 31494285 PMCID: PMC7258745 DOI: 10.1016/j.nbd.2019.104604] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/26/2019] [Accepted: 09/04/2019] [Indexed: 12/20/2022] Open
Abstract
Fragile X syndrome (FXS) is associated with deficits in various types of learning, including those that require the hippocampus. Relatedly, hippocampal long-term potentiation (LTP) is impaired in the Fmr1 knockout (KO) mouse model of FXS. Prior research found that infusion of brain-derived neurotrophic factor (BDNF) rescues LTP in the KOs. Here, we tested if, in Fmr1 KO mice, up-regulating BDNF production or treatment with an agonist for BDNF's TrkB receptor restores synaptic plasticity and improves learning. In hippocampal slices, bath infusion of the TrkB agonist 7,8-dihydroxyflavone (7,8-DHF) completely restored otherwise impaired hippocampal field CA1 LTP of Fmr1 KOs without effect in wild types (WTs). Similarly, acute, semi-chronic, or chronic treatments with 7,8-DHF rescued a simple hippocampus-dependent form of spatial learning (object location memory: OLM) in Fmr1 KOs without effect in WTs. The agonist also restored object recognition memory, which depends on cortical regions. Semi-chronic, but not acute, treatment with the ampakine CX929, which up-regulates BDNF expression, lowered the training threshold for OLM in WT mice and rescued learning in the KOs. Positive results were also obtained in a test for social recognition. An mGluR5 antagonist did not improve learning. Quantification of synaptic immunolabeling demonstrated that 7,8-DHF and CX929 increase levels of activated TrkB at excitatory synapses. Moreover, CX929 induced a robust synaptic activation of the TrkB effector ERK1/2. These results suggest that enhanced synaptic BDNF signaling constitutes a plausible strategy for treating certain aspects of the cognitive disabilities associated with FXS.
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Affiliation(s)
- Ronald R Seese
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America
| | - Aliza A Le
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America
| | - Kathleen Wang
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America
| | - Conor D Cox
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America
| | - Gary Lynch
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America; Department of Psychiatry and Human Behavior, University of California, Irvine, CA, United States of America.
| | - Christine M Gall
- Department of Anatomy and Neurobiology, University of California, Irvine, CA, United States of America; Department of Neurobiology and Behavior, University of California, Irvine, CA, United States of America.
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Radin DP, Li YX, Rogers G, Purcell R, Lippa A. Tarps differentially affect the pharmacology of ampakines. Biochem Pharmacol 2018; 154:446-451. [PMID: 29906466 DOI: 10.1016/j.bcp.2018.06.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 06/11/2018] [Indexed: 12/29/2022]
Abstract
Transmembrane AMPA receptor regulatory proteins (TARPs) govern AMPA receptor cell surface expression and distinct physiological properties including agonist affinity, desensitization and deactivation kinetics. The prototypical TARP, STG or γ2 and TARPs γ3, γ4, γ7 and γ8 are all expressed to varying degrees in the mammalian brain and differentially regulate AMPAR gating parameters. Positive allosteric AMPA receptor modulators or ampakines alter receptor rates of agonist binding/unbinding, channel opening and can offset receptor desensitization and deactivation. The effects of the two ampakines, CX614 and cyclothiazide (CTZ) were evaluated on homomeric GluR1-flip receptors and GluR2-flop receptors expressed on HEK293 cells by transient transfection with or without different TARPs γ2, γ3, γ4 or γ8 genes. γ4 was the most robust TARP in increasing the affinities of CX614 and CTZ on GluR1-flip receptors, but had no such effect on GluR2-flop receptors. However, γ8 gave the most significant increases in affinities of CX614 and CTZ on GluR2-flop. These data show that TARPs differentially affect the surface expression and kinetics of the AMPA receptor, as well as the pharmacology of ampakines for the AMPA receptor. The modulatory effects of TARPs on ampakine pharmacology are complex, being dependent on both the TARP subtype and the AMPA receptor subtypes/isoforms.
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Affiliation(s)
- Daniel P Radin
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452,United States.
| | - Yong-Xin Li
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452,United States
| | - Gary Rogers
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452,United States
| | - Richard Purcell
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452,United States
| | - Arnold Lippa
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452,United States
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Radin DP, Rogers GA, Hewitt KE, Purcell R, Lippa A. Ampakines Attenuate Staurosporine-induced Cell Death in Primary Cortical Neurons: Implications in the 'Chemo-Brain' Phenomenon. Anticancer Res 2018; 38:3461-3465. [PMID: 29848697 DOI: 10.21873/anticanres.12615] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 04/23/2018] [Accepted: 04/30/2018] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM Mounting evidence suggests that trophic cell signaling can be mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) activation. It has been demonstrated that exogenous application of brain-derived neurotrophic factor (BDNF) is highly neuroprotective in vitro against neurotoxic insults such as standard chemotherapies. MATERIALS AND METHODS Because positive allosteric modulation of AMPARs with ampakines can increase both BDNF mRNA and protein in vitro and in vivo, we examined whether application of the ampakines CX614 and CX729 promoted neuroprotection against staurosporine-induced cell death in rat primary cortical neurons using propidium iodide to stain for dead cells. RESULTS A transient 2-h pretreatment with CX614 or CX729 performed 24 h prior to staurosporine produced significant, time-dependent neuroprotection that was resistant to the AMPAR antagonists NBQX or GYKI 52466, suggesting that this effect may be independent of ion flow. Furthermore, the pretreatment time requirements of CX729 matched the time course for increased BDNF expression previously reported to occur in hippocampal slices, suggesting that increased neurotrophin expression might be associated with the neuroprotective effects conferred by ampakines. CONCLUSION Our data demonstrate that ampakines may be able to perturb neuronal toxicity and peripheral neuropathy of front-line chemotherapies.
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Affiliation(s)
| | - Gary A Rogers
- RespireRx Pharmaceuticals, Inc., Glen Rock, NJ, U.S.A
| | | | | | - Arnold Lippa
- RespireRx Pharmaceuticals, Inc., Glen Rock, NJ, U.S.A
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Radin DP, Li YX, Rogers G, Purcell R, Lippa A. Stargazin differentially modulates ampakine gating kinetics and pharmacology. Biochem Pharmacol 2018; 148:308-314. [PMID: 29330065 DOI: 10.1016/j.bcp.2018.01.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/05/2018] [Indexed: 12/22/2022]
Abstract
It was previously reported that Stargazin (STG) enhances the surface expression of AMPA receptors, controls receptor gating and slows channel desensitization as an auxiliary subunit of the receptors. Ampakines are a class of AMPA receptor positive allosteric modulators that modify rates of transmitter binding, channel activity and desensitization parameters. As such, they have shown efficacy in animal models of neurodegenerative diseases, where excitatory synaptic transmission is compromised. Given the functional similarities between STG and ampakines, the current study sought to probe interactions between STG and ampakine gating properties. The effects of the high impact ampakines, CX614 and cyclothiazide (CTZ), were compared with homomeric GluR1-flip (Glur1i) and GluR2-flop (Glur2o) receptors expressed in HEK293 cells by transient transfection with or without STG gene. STG dramatically enhanced the surface expression of AMPA receptors and increased glutamate-induced steady-state currents during desensitization. STG also increased ratios of 500 μM kainate and 500 μM glutamate activated steady-state currents. STG reduced association rates of ampakines and differentially affected the dissociation rates for both CX614 and CTZ on desensitized receptors. The estimated Kd value for CX614 was lowered from 340 μM to 70 μM, whereas that for CTZ was lowered from 170 μM to 6 μM by STG. The data suggest that Stargazin can dramatically alter the conformation of the receptor dimer interface where CX614 and CTZ are known to bind. This work also demonstrates the importance of considering STG interactions when developing ampakines to treat neurodegenerative diseases in which AMPAergic signaling is compromised.
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Affiliation(s)
- Daniel P Radin
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452, United States.
| | - Yong-Xin Li
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452, United States
| | - Gary Rogers
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452, United States
| | - Richard Purcell
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452, United States
| | - Arnold Lippa
- RespireRx Pharmaceuticals Inc., 126 Valley Road, Glen Rock, NJ 07452, United States
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Radin DP, Purcell R, Lippa AS. Oncolytic Properties of Ampakines In Vitro. Anticancer Res 2018; 38:265-269. [PMID: 29277782 DOI: 10.21873/anticanres.12217] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM The 5-year survival rate of glioblastoma (GBM) is ~10%, demonstrating that a new therapeutic modality for this cancer is desperately needed. Complicating the search for such a modality is that most large molecules cannot pass through the blood brain barrier, so molecules demonstrating efficacy in vitro may not be useful in vivo because they never reach the brain. Recently, the selective serotonin reuptake inhibitor (SSRI) fluoxetine (FLX) was identified as an effective agent in targeting GBM in vitro and in vivo by agonizing AMPA-glutamate receptors (AMPARs), eliciting massive calcium influx and mitochondrial calcium overload and apoptosis. MATERIALS AND METHODS In the current study, we used a colorimetric cell viability assay to determine if we could enhance the oncolytic effect of FLX in vitro by pre-treating cells with an AMPAR-positive allosteric modulator (Ampakine). RESULTS Our results demonstrated for the first time that concentrations of the Class I ampakine CX614, which increase AMPAR agonist binding affinity, possess oncolytic activity as a sole agent and synergistically reduce GBM viability when paired with FLX. FLX also demonstrates a dose-dependent induction of apoptosis in cancer cells originating outside the CNS that overexpress calcium-permeable AMPARs. Likewise, CX614 inhibits cancer cell viability in a dose-dependent fashion and its combination with FLX synergistically reduces cell viability. These effects of CX614 were not seen with the Class II ampakines, CX717 and CX1739. CONCLUSION CX614 inhibits the growth of multiple cancers in vitro and bolsters the oncolytic activity of FLX in several cancers.
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