Publications by authors named "Jane E Cavanaugh"

26 Publications

  • Page 1 of 1

Constitutive activation of MEK5 promotes a mesenchymal and migratory cell phenotype in triple negative breast cancer.

Oncoscience 2021 18;8:64-71. Epub 2021 May 18.

Department of Medicine, Division of Hematology and Oncology, Tulane University, New Orleans, LA 70118, USA.

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited targeted therapeutic options. A defining feature of TNBC is the propensity to metastasize and acquire resistance to cytotoxic agents. Mitogen activated protein kinase (MAPK) and extracellular regulated kinase (ERK) signaling pathways have integral roles in cancer development and progression. While MEK5/ERK5 signaling drives mesenchymal and migratory cell phenotypes in breast cancer, the specific mechanisms underlying these actions remain under-characterized. To elucidate the mechanisms through which MEK5 regulates the mesenchymal and migratory phenotype, we generated stably transfected constitutively active MEK5 (MEK5-ca) TNBC cells. Downstream signaling pathways and candidate targets of MEK5-ca cells were based on RNA sequencing and confirmed using qPCR and Western blot analyses. MEK5 activation drove a mesenchymal cell phenotype independent of cell proliferation effects. Transwell migration assays demonstrated MEK5 activation significantly increased breast cancer cell migration. In this study, we provide supporting evidence that MEK5 functions through FRA-1 to regulate the mesenchymal and migratory phenotype in TNBC.
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http://dx.doi.org/10.18632/oncoscience.535DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8131078PMC
May 2021

Dual inhibition of MEK1/2 and MEK5 suppresses the EMT/migration axis in triple-negative breast cancer through FRA-1 regulation.

J Cell Biochem 2021 08 20;122(8):835-850. Epub 2021 Apr 20.

Department of Medicine, Section of Hematology and Oncology, Tulane University School of Medicine, New Orleans, Louisiana, USA.

Triple-negative breast cancer (TNBC) presents a clinical challenge due to the aggressive nature of the disease and a lack of targeted therapies. Constitutive activation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway has been linked to chemoresistance and metastatic progression through distinct mechanisms, including activation of epithelial-to-mesenchymal transition (EMT) when cells adopt a motile and invasive phenotype through loss of epithelial markers (CDH1), and acquisition of mesenchymal markers (VIM, CDH2). Although MAPK/ERK1/2 kinase inhibitors (MEKi) are useful antitumor agents in a clinical setting, including the Food and Drug Administration (FDA)-approved MEK1,2 dual inhibitors cobimetinib and trametinib, there are limitations to their clinical utility, primarily adaptation of the BRAF pathway and ocular toxicities. The MEK5 (HGNC: MAP2K5) pathway has important roles in metastatic progression of various cancer types, including those of the prostate, colon, bone and breast, and elevated levels of ERK5 expression in breast carcinomas are linked to a worse prognoses in TNBC patients. The purpose of this study is to explore MEK5 regulation of the EMT axis and to evaluate a novel pan-MEK inhibitor on clinically aggressive TNBC cells. Our results show a distinction between the MEK1/2 and MEK5 cascades in maintenance of the mesenchymal phenotype, suggesting that the MEK5 pathway may be necessary and sufficient in EMT regulation while MEK1/2 signaling further sustains the mesenchymal state of TNBC cells. Furthermore, additive effects on MET induction are evident through the inhibition of both MEK1/2 and MEK5. Taken together, these data demonstrate the need for a better understanding of the individual roles of MEK1/2 and MEK5 signaling in breast cancer and provide a rationale for the combined targeting of these pathways to circumvent compensatory signaling and subsequent therapeutic resistance.
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http://dx.doi.org/10.1002/jcb.29916DOI Listing
August 2021

Diverse and converging roles of ERK1/2 and ERK5 pathways on mesenchymal to epithelial transition in breast cancer.

Transl Oncol 2021 Jun 21;14(6):101046. Epub 2021 Mar 21.

Department of Pharmacology, School of Pharmacy, Duquesne University, Pittsburgh, PA 15219, USA. Electronic address:

The epithelial to mesenchymal transition (EMT) is characterized by a loss of cell polarity, a decrease in the epithelial cell marker E-cadherin, and an increase in mesenchymal markers including the zinc-finger E-box binding homeobox (ZEB1). The EMT is also associated with an increase in cell migration and anchorage-independent growth. Induction of a reversal of the EMT, a mesenchymal to epithelial transition (MET), is an emerging strategy being explored to attenuate the metastatic potential of aggressive cancer types, such as triple-negative breast cancers (TNBCs) and tamoxifen-resistant (TAMR) ER-positive breast cancers, which have a mesenchymal phenotype. Patients with these aggressive cancers have poor prognoses, quick relapse, and resistance to most chemotherapeutic drugs. Overexpression of extracellular signal-regulated kinase (ERK) 1/2 and ERK5 is associated with poor patient survival in breast cancer. Moreover, TNBC and tamoxifen resistant cancers are unresponsive to most targeted clinical therapies and there is a dire need for alternative therapies. In the current study, we found that MAPK3, MAPK1, and MAPK7 gene expression correlated with EMT markers and poor overall survival in breast cancer patients using publicly available datasets. The effect of ERK1/2 and ERK5 pathway inhibition on MET was evaluated in MDA-MB-231, BT-549 TNBC cells, and tamoxifen-resistant MCF-7 breast cancer cells. Moreover, TU-BcX-4IC patient-derived primary TNBC cells were included to enhance the translational relevance of our study. We evaluated the effect of pharmacological inhibitors and lentivirus-induced activation or inhibition of the MEK1/2-ERK1/2 and MEK5-ERK5 pathways on cell morphology, E-cadherin, vimentin and ZEB1 expression. Additionally, the effects of pharmacological inhibition of trametinib and XMD8-92 on nuclear localization of ERK1/2 and ERK5, cell migration, proliferation, and spheroid formation were evaluated. Novel compounds that target the MEK1/2 and MEK5 pathways were used in combination with the AKT inhibitor ipatasertib to understand cell-specific responses to kinase inhibition. The results from this study will aid in the design of innovative therapeutic strategies that target cancer metastases.
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http://dx.doi.org/10.1016/j.tranon.2021.101046DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8020482PMC
June 2021

Molecular Mechanisms of Epithelial to Mesenchymal Transition Regulated by ERK5 Signaling.

Biomolecules 2021 01 29;11(2). Epub 2021 Jan 29.

Department of Pharmacology, School of Pharmacy, Duquesne University, Pittsburgh, PA 15282, USA.

Extracellular signal-regulated kinase (ERK5) is an essential regulator of cancer progression, tumor relapse, and poor patient survival. Epithelial to mesenchymal transition (EMT) is a complex oncogenic process, which drives cell invasion, stemness, and metastases. Activators of ERK5, including mitogen-activated protein kinase 5 (MEK5), tumor necrosis factor α (TNF-α), and transforming growth factor-β (TGF-β), are known to induce EMT and metastases in breast, lung, colorectal, and other cancers. Several downstream targets of the ERK5 pathway, such as myocyte-specific enhancer factor 2c (MEF2C), activator protein-1 (AP-1), focal adhesion kinase (FAK), and c-Myc, play a critical role in the regulation of EMT transcription factors SNAIL, SLUG, and β-catenin. Moreover, ERK5 activation increases the release of extracellular matrix metalloproteinases (MMPs), facilitating breakdown of the extracellular matrix (ECM) and local tumor invasion. Targeting the ERK5 signaling pathway using small molecule inhibitors, microRNAs, and knockdown approaches decreases EMT, cell invasion, and metastases via several mechanisms. The focus of the current review is to highlight the mechanisms which are known to mediate cancer EMT via ERK5 signaling. Several therapeutic approaches that can be undertaken to target the ERK5 pathway and inhibit or reverse EMT and metastases are discussed.
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http://dx.doi.org/10.3390/biom11020183DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7911413PMC
January 2021

ERK5 Is Required for Tumor Growth and Maintenance Through Regulation of the Extracellular Matrix in Triple Negative Breast Cancer.

Front Oncol 2020 3;10:1164. Epub 2020 Aug 3.

Section of Hematology & Medical Oncology, Department of Medicine, Tulane University School of Medicine, New Orleans, LA, United States.

Conventional mitogen-activated protein kinase (MAPK) family members regulate diverse cellular processes involved in tumor initiation and progression, yet the role of ERK5 in cancer biology is not fully understood. Triple-negative breast cancer (TNBC) presents a clinical challenge due to the aggressive nature of the disease and a lack of targeted therapies. ERK5 signaling contributes to drug resistance and metastatic progression through distinct mechanisms, including activation of epithelial-to-mesenchymal transition (EMT). More recently a role for ERK5 in regulation of the extracellular matrix (ECM) has been proposed, and here we investigated the necessity of ERK5 in TNBC tumor formation. Depletion of ERK5 expression using the CRISPR/Cas9 system in MDA-MB-231 and Hs-578T cells resulted in loss of mesenchymal features, as observed through gene expression profile and cell morphology, and suppressed TNBC cell migration. xenograft experiments revealed ERK5 knockout disrupted tumor growth kinetics, which was restored using high concentration Matrigel™ and ERK5-ko reduced expression of the angiogenesis marker CD31. These findings implicated a role for ERK5 in the extracellular matrix (ECM) and matrix integrity. RNA-sequencing analyses demonstrated downregulation of matrix-associated genes, integrins, and pro-angiogenic factors in ERK5-ko cells. Tissue decellularization combined with cryo-SEM and interrogation of biomechanical properties revealed that ERK5-ko resulted in loss of key ECM fiber alignment and mechanosensing capabilities in breast cancer xenografts compared to parental wild-type cells. In this study, we identified a novel role for ERK5 in tumor growth kinetics through modulation of the ECM and angiogenesis axis in breast cancer.
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http://dx.doi.org/10.3389/fonc.2020.01164DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7416559PMC
August 2020

Pharmacological inhibition of the MEK5/ERK5 and PI3K/Akt signaling pathways synergistically reduces viability in triple-negative breast cancer.

J Cell Biochem 2020 02 28;121(2):1156-1168. Epub 2019 Aug 28.

Department of Pharmacology and Toxicology, Duquesne University, Pittsburgh, Pennsylvania.

Triple-negative breast cancers (TNBCs) represent 15% to 20% of all breast cancers and are often associated with poor prognosis. The lack of targeted therapies for TNBCs contributes to higher mortality rates. Aberrations in the phosphoinositide-3-kinase (PI3K) and mitogen-activated protein kinase pathways have been linked to increased breast cancer proliferation and survival. It has been proposed that these survival characteristics are enhanced through compensatory signaling and crosstalk mechanisms. While the crosstalk between PI3K and extracellular signal-regulated kinase 1/2 (ERK1/2) pathways has been characterized in several systems, new evidence suggests that MEK5/ERK5 signaling is a key component in the proliferation and survival of several aggressive cancers. In this study, we examined the effects of dual inhibition of PI3K/protein kinase B (Akt) and MEK5/ERK5 in the MDA-MB-231, BT-549, and MDA-MB-468 TNBC cell lines. We used the Akt inhibitor ipatasertib, ERK5 inhibitors XMD8-92 and AX15836, and the novel MEK5 inhibitor SC-1-181 to investigate the effects of dual inhibition. Our results indicated that dual inhibition of PI3K/Akt and MEK5/ERK5 signaling was more effective at reducing the proliferation and survival of TNBCs than single inhibition of either pathway alone. In particular, a loss of Bad phosphorylation at two distinct sites was observed with dual inhibition. Furthermore, the inhibition of both pathways led to p21 restoration, decreased cell proliferation, and induced apoptosis. In addition, the dual inhibition strategy was determined to be synergistic in MDA-MB-231 and BT-549 cells and was relatively nontoxic in the nonneoplastic MCF-10 cell line. In summary, the results from this study provide a unique prospective into the utility of a novel dual inhibition strategy for targeting TNBCs.
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http://dx.doi.org/10.1002/jcb.29350DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6923606PMC
February 2020

Novel Diphenylamine Analogs Induce Mesenchymal to Epithelial Transition in Triple Negative Breast Cancer.

Front Oncol 2019 30;9:672. Epub 2019 Jul 30.

Division of Medicinal Chemistry, School of Pharmacy, Duquesne University, Pittsburgh, PA, United States.

Epithelial to mesenchymal transition (EMT) is a cellular program that converts non-motile epithelial cells into invasive mesenchymal cells. EMT is implicated in cancer metastasis, chemo-resistance, cancer progression, and generation of cancer stem cells (CSCs). Inducing mesenchymal to epithelial transition (MET), the reverse phenomenon of EMT, is proposed as a novel strategy to target triple negative and tamoxifen-resistant breast cancer. Triple negative breast cancer (TNBC) is characterized by the loss of hormone receptors, a highly invasive mesenchymal phenotype, and a lack of targeted therapy. Estrogen receptor-positive breast cancer can be targeted by tamoxifen, an ER antagonist. However, these cells undergo EMT over the course of treatment and develop resistance. Thus, there is an urgent need to develop therapeutic interventions to target these aggressive cancers. In this study, we examined the role of novel diphenylamine analogs in converting the mesenchymal phenotype of MDA-MB-231 TNBC cells to a lesser aggressive epithelial phenotype. Using analog-based drug design, a series of diphenylamine analogs were synthesized and initially evaluated for their effect on E-cadherin protein expression and changes incell morphology, which was quantified by measuring the spindle index (SI) value. Selected compound from this series increases the expression of E-cadherin, a primary marker for epithelial cells, and decreases the mesenchymal markers SOX2, ZEB1, Snail, and vimentin. The increase in epithelial markers and the decrease in mesenchymal markers are consistent with a phenotypic switch from spindle-like morphology to cobblestone-like morphology. Furthermore, Compound decreases spheroid viability, cell migration, and cell proliferation in triple negative BT-549 and tamoxifen-resistant MCF-7 breast cancer cells.
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http://dx.doi.org/10.3389/fonc.2019.00672DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6682674PMC
July 2019

Breaking Down Barriers to Pharmacy Graduate Education: The Report of the 2017-2018 Research and Graduate Affairs Committee.

Am J Pharm Educ 2018 09;82(7):7147

American Association of Colleges of Pharmacy, Arlington, Virginia.

The 2017-2018 Research and Graduate Affairs Committee (RGAC) was given three charges aimed at helping academic pharmacy address barriers that must be overcome by both students and schools to attract, retain, and support the development of a diverse, well-rounded, and successful graduate student population. These charges were (1) identifying teaching methodologies, tools and opportunities that graduate programs can introduce into curriculum to overcome barriers to success of today's and tomorrow's learners; (2) developing a strategy for achieving member support of the 2016-2017 recommended graduate competencies by identifying gaps in and existing examples of courses or opportunities that achieve competency-based pharmacy graduate education; and (3) identifying potential strategies to address identified barriers to pursuing graduate education, especially among under-represented student populations. This report describes attitudes toward and opportunities related to competency-based education in graduation education in colleges and schools of pharmacy, identifies types of tools schools could use to enhance training towards the competency framework developed by the 2016-2017 RGAC, particularly with regards to the so-called power skills, and outlines a role for AACP in facilitating this training. This report also considers a number of barriers, both perceived and real, that potential students encounter when considering graduate training and suggests strategies to understand the impact of and mitigate these barriers. To strengthen competency-based graduate education, the RGAC puts forth two recommendations that AACP develop a toolkit supporting the training of power skills and that AACP should develop or curate programs or tools to support the use of individual development plans (IDPs). The RGAC also puts forth a suggestion to schools that IDPs be implemented for all students. In considering the barriers to pursuing graduate education, the Committee proposes one policy statement that AACP supports the training and development of an increasingly diverse population of researchers at pharmacy schools through active efforts to promote M.S. and Ph.D. education along with Pharm.D. education. Additionally, the Committee provides recommendations that AACP should expand its efforts in career tracking of graduate students to include collection and/or analysis of data that could inform the Academy's understanding of barriers to pursuing graduate education in pharmacy schools, the AACP Office of Institutional Research and Effectiveness should expand upon graduate program data described in the annual Profile of Pharmacy Students report, and finally that AACP should include graduate programs in efforts to increase diversity of students at pharmacy schools.
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http://dx.doi.org/10.5688/ajpe7147DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6181166PMC
September 2018

Structure activity relationships of anthranilic acid-based compounds on cellular and in vivo mitogen activated protein kinase-5 signaling pathways.

Bioorg Med Chem Lett 2018 07 20;28(13):2294-2301. Epub 2018 May 20.

Department of Pharmacology, School of Pharmacy, Duquesne University, 410A Mellon Hall, 600 Forbes Ave., Pittsburgh, PA 15282, United States.

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http://dx.doi.org/10.1016/j.bmcl.2018.05.029DOI Listing
July 2018

Resveratrol and pinostilbene confer neuroprotection against aging-related deficits through an ERK1/2-dependent mechanism.

J Nutr Biochem 2018 04 4;54:77-86. Epub 2017 Nov 4.

Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282, United States. Electronic address:

Age-related declines in motor function may be due, in part, to an increase in oxidative stress in the aging brain leading to dopamine (DA) neuronal cell death. In this study, we examined the neuroprotective effects of natural antioxidants resveratrol and pinostilbene against age-related DAergic cell death and motor dysfunction using SH-SY5Y neuroblastoma cells and young, middle-aged, and old male C57BL/6 mice. Resveratrol and pinostilbene protected SH-SY5Y cells from a DA-induced decrease in cell viability. Dietary supplementation with resveratrol and pinostilbene inhibited the decline of motor function observed with age. While DA and its metabolites (DOPAC and HVA), dopamine transporter, and tyrosine hydroxylase levels remain unchanged during aging or treatment, resveratrol and pinostilbene increased ERK1/2 activation in vitro and in vivo in an age-dependent manner. Inhibition of ERK1/2 in SH-SY5Y cells decreased the protective effects of both compounds. These data suggest that resveratrol and pinostilbene alleviate age-related motor decline via the promotion of DA neuronal survival and activation of the ERK1/2 pathways.
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http://dx.doi.org/10.1016/j.jnutbio.2017.10.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5866762PMC
April 2018

Competency, Programming, and Emerging Innovation in Graduate Education within Schools of Pharmacy: The Report of the 2016-2017 Research and Graduate Affairs Committee.

Am J Pharm Educ 2017 Oct;81(8):S11

University of Illinois at Chicago College of Pharmacy, Chicago, Illinois.

Graduate education in the pharmaceutical sciences is a cornerstone of research within pharmacy schools. Pharmaceutical scientists are critical contributors to addressing the challenges of new drug discovery, delivery, and optimal care in order to ensure improved therapeutic outcomes in populations of patients. The American Association of Colleges of Pharmacy (AACP) charged the 2016-2017 Research and Graduate Affairs Committee (RGAC) to define the competencies necessary for graduate education in the pharmaceutical sciences (Charge 1), recommend collaborative curricular development across schools of pharmacy (Charge 2), recommend AACP programing for graduate education (Charge 3), and provide guidance on emerging areas for innovation in graduate education (Charge 4). With respect to Charges 1 and 2, the RGAC committee developed six domains of core competencies for graduate education in the pharmaceutical sciences as well as recommendations for shared programming. For Charge 3, the committee made 3 specific programming recommendations that include AACP sponsored regional research symposia, a professional development forum at the AACP INterim Meeting, and the addition of a graduate research and education poster session at the AACP Annual Meeting. For Charge 4, the committee recommended that AACP develop a standing committee of graduate program deans and directors to provide guidance to member schools in support of graduate program representation at AACP meetings, develop skills for interprofessional teamwork and augment research through integration of Pharm.D., Ph.D., postdoctoral associates, resident, and fellow experiences. Two proposed policy statements by the committee are that AACP believes core competencies are essential components of graduate education and AACP supports the inclusion of research and graduate education focuses in its portfolio of meetings and programs.
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http://dx.doi.org/10.5688/ajpeS11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5701334PMC
October 2017

Protective effects of the resveratrol analog piceid in dopaminergic SH-SY5Y cells.

Arch Toxicol 2018 Feb 4;92(2):669-677. Epub 2017 Oct 4.

Division of Pharmaceutical Sciences, Department of Pharmacology, Mylan School of Pharmacy, Duquesne University, Pittsburgh, PA, USA.

Age-related motor deficits, such as loss of balance and coordination, are caused, in part, by loss of dopaminergic neurons. Oxidative stress is known to play a role in this neuronal loss. Resveratrol, a natural antioxidant with anticancer and anti-inflammatory potential, has been shown to protect dopaminergic-like cells (SH-SY5Y) against oxidative stress. However, the low bioavailability of resveratrol makes it worthwhile to explore newer compounds with similar properties. Piceid (RV8), an analog of resveratrol, has greater bioavailability than resveratrol, and our studies found that piceid (10, 20, 30 µM) protects SH-SY5Y cells against oxidative stress. Our investigations also found that the neuroprotection afforded by piceid was decreased when the MAP kinases, ERK1/2 and ERK5, were independently inhibited. Since oxidative stress is considered a master operator of apoptosis, our study also scrutinized dopamine-induced apoptosis and whether caspase-3/7 and Bcl-2 are involved, following piceid pretreatment followed by dopamine exposure. Our findings suggested that piceid pretreatment inhibited the dopamine-induced increase in caspase-3/7 activity and dopamine-induced loss of Bcl-2 expression. Overall, these findings suggest that the neuroprotective effects of piceid are mediated via the activation of ERK1/2, ERK5, and inhibition of apoptosis caused by oxidative stress.
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http://dx.doi.org/10.1007/s00204-017-2073-zDOI Listing
February 2018

Central amygdala activation of extracellular signal-regulated kinase 1 and age-dependent changes in inflammatory pain sensitivity in mice.

Neurobiol Aging 2017 08 26;56:100-107. Epub 2017 Apr 26.

Department of Biological Sciences, Duquesne University, Pittsburgh, PA, USA; Chronic Pain Research Consortium, Duquesne University, Pittsburgh, PA, USA; Aging Research and Teaching Consortium, Duquesne University, Pittsburgh, PA, USA. Electronic address:

Aging populations are more sensitive to noxious stimuli as a result of altered somatosensory systems. In these experiments, we examined pain-like behaviors in young, middle-aged, and old mice during peripheral inflammation to determine if the same sensitivity exists in preclinical animal models. Immediately following injury, middle-aged and old mice exhibited more spontaneous pain-like behaviors than young mice, matching pain prevalence in clinical populations. Middle-aged and old mice also developed persistent mechanical hypersensitivity in the injured paw. Furthermore, old mice developed mechanical hypersensitivity in the noninjured paw suggesting age-dependent changes in central nociceptive systems. To address this end, pain-related protein expression was examined in the central nucleus of the amygdala, a limbic brain region that modulates somatic pain. Following injury, increased phosphorylation of extracellular signal-regulated kinase 1, a protein with known nociceptive functions, was observed in the right central nucleus of the amygdala of old mice and not middle-aged or young animals. These findings suggest that age-dependent changes in supraspinal nociceptive systems may account for increased pain-like behaviors in aging populations.
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http://dx.doi.org/10.1016/j.neurobiolaging.2017.04.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5497765PMC
August 2017

Oncogenic signaling of MEK5-ERK5.

Cancer Lett 2017 04 30;392:51-59. Epub 2017 Jan 30.

Department of Medicine-Section of Hematology and Medical Oncology, Tulane University, New Orleans, LA, USA; Department of Pharmacology, Tulane University, New Orleans, LA, USA; Tulane Cancer Center, Tulane University, New Orleans, LA, USA. Electronic address:

Mitogen-activated protein kinases (MAPKs) regulate diverse cellular processes including proliferation, cell survival, differentiation, and apoptosis. While conventional MAPK constituents have well-defined roles in oncogenesis, the MEK5 pathway has only recently emerged in cancer research. In this review, we consider the MEK5 signaling cascade, focusing specifically on its involvement in drug resistance and regulation of aggressive cancer phenotypes. Moreover, we explore the role of MEK5/ERK5 in tumorigenesis and metastatic progression, discussing the discrepancies in preclinical studies and assessing its viability as a therapeutic target for anti-cancer agents.
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http://dx.doi.org/10.1016/j.canlet.2017.01.034DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5901897PMC
April 2017

Development and characterization of resveratrol nanoemulsions carrying dual-imaging agents.

Ther Deliv 2016 12 11;7(12):795-808. Epub 2016 Nov 11.

Graduate School of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, Pittsburgh, PA 15282, USA.

Aim: Delivery of the natural anti-inflammatory compound resveratrol with nanoemulsions can dramatically improve its tissue targeting, bioavailability and efficacy. Current assessment of resveratrol delivery efficacy is limited to indirect pharmacological measures. Molecular imaging solves this problem. Results/methodology: Nanoemulsions containing two complementary imaging agents, near-infrared dye and perfluoropolyether (PFPE), were developed and evaluated. Nanoemulsion effects on macrophage uptake, toxicity and NO production were also evaluated. The presence of PFPE did not affect nanoemulsion size, zeta potential, colloidal stability, drug loading or drug release.

Conclusion: PFPE nanoemulsions can be used in future studies to evaluate nanoemulsion biodistribution without interfering with resveratrol delivery and pharmacological outcomes. Developed nanoemulsions show promise as a versatile treatment strategy for cancer and other inflammatory diseases. [Formula: see text].
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http://dx.doi.org/10.4155/tde-2016-0050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5239992PMC
December 2016

Improved Flux of Levodopa via Direct Deposition of Solid Microparticles on Nasal Tissue.

AAPS PharmSciTech 2017 Apr 5;18(3):904-912. Epub 2016 Jul 5.

Graduate School of Pharmaceutical Sciences, Duquesne University, 600 Forbes Avenue, Pittsburgh, Pennsylvania, 15282, USA.

Epithelial flux and permeability across bovine olfactory tissue were compared when levodopa (L-DOPA) was loaded in different physical states. Aqueous solution of L-DOPA was prepared in Krebs-Ringer buffer (KRB), at a concentration (0.75 mg/mL) verified to be less than the saturation solubility at both 25 and 37°C. Sodium metabisulfite was added to solution to minimize L-DOPA oxidation; chemical stability of aqueous L-DOPA was evaluated using HPLC-UV. Solid-state characterization of unprocessed, dry, crystalline L-DOPA powder was performed using TGA, DSC, PXRD, and optical microscopy to ensure that preparation of L-DOPA microparticles used for diffusion experiments did not elicit a phase change. Measurements of in vitro flux were made for all preparations, using freshly excised bovine olfactory mucosal membrane. Samples obtained from transport studies were analyzed by HPLC-UV. Tissue viability was measured before and after experiments using transdermal epithelial electrical resistance (TEER). The average steady-state flux (J ) of L-DOPA from solid microparticles directly deposited on nasal epithelial tissue was 6.08 ± 0.69 μg/cm/min, approximately three times greater than the J measured for L-DOPA from solution (2.13 ± 0.97 μg/cm/min). The average apparent permeability coefficient (P ) of L-DOPA was calculated to be 4.73 × 10 cm/s. These findings suggest that nasal delivery of L-DOPA by administration of solid microparticles not only benefits from improved chemical and microbiological stability by avoiding the use of aqueous formulation vehicle but also does not compromise cumulative mass transport across the olfactory membrane.
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http://dx.doi.org/10.1208/s12249-016-0581-4DOI Listing
April 2017

ERK1, 2, and 5 expression and activation in dopaminergic brain regions during postnatal development.

Int J Dev Neurosci 2015 Nov 7;46:44-50. Epub 2015 Aug 7.

Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University 600 Forbes Avenue, Pittsburgh, PA 15282, United States. Electronic address:

Degeneration and dysfunctioning of dopaminergic neurons in the midbrain have been associated with serious neurodegenerative and neuropsychiatric disorders. Elucidating the underlying neurobiology of these neurons during early postnatal development may provide important information regarding the etiology of these disorders. Cellular signaling pathways have been shown to regulate postnatal neuronal development. Among several signaling pathways, extracellular-regulated mitogen kinases (ERK) 1, 2, and 5 have been shown to be crucial for the survival and function of dopaminergic neurons. In this study, the basal expression and activation of ERK1, 2, and 5 were studied during postnatal development in regions rich in DA cells and terminals. In the striatum (STR) and ventral mesencephalon regions of the substantia nigra (SN) and ventral tegmental area (VTA), ERK5 expression and activation were high during early postnatal days and declined with aging. Interestingly, sharp increases in phosphorylated or activated ERK1 and ERK2 were observed at postnatal day (PND) 7 in the SN and VTA. In contrast, in the STR, the levels of phosphorylated ERK1 and 2 were significantly higher at PND0 than at any other PND examined. Overall, the understanding of alterations in ERK signaling in regions rich in DA cells and DA terminals during postnatal neuronal development may provide information about their role in regulation of dopamine neuronal development which may ultimately provide insight into the underlying mechanisms of dopamine neurodegeneration.
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http://dx.doi.org/10.1016/j.ijdevneu.2015.06.009DOI Listing
November 2015

Dietary supplementation with resveratrol protects against striatal dopaminergic deficits produced by in utero LPS exposure.

Brain Res 2014 Jul 23;1573:37-43. Epub 2014 May 23.

Division of Pharmacology, Graduate School of Pharmaceutical Sciences, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282, USA. Electronic address:

The purpose of this study was to determine the effect of dietary supplementation with the anti-inflammatory compound resveratrol in pregnant dams on lipopolysaccharide (LPS)-induced dopaminergic deficits in pups exposed to LPS in utero. Gravid female rats were fed with a resveratrol-enriched diet during gestational days 3-22.5 (E3-E22.5) and received an intraperitoneal (i.p.) injection of 1mg/kg LPS at E10.5. The striata were isolated from the pups at postnatal days 10 (P10) and P21. LPS-induced dopaminergic deficits were noted at P21, but not P10. These DA deficits at P21 were exhibited by a loss of DA and DA metabolite [3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA)] levels and tyrosine hydroxylase (TH) expression in the striatum. The LPS-induced loss of DA, DA metabolites, and TH expression were attenuated in the striata of pups from the dams fed with the resveratrol-supplemented diet. These data suggest that a resveratrol-supplemented diet may restore homeostasis of the striatal DA neuronal system following disruption by LPS.
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http://dx.doi.org/10.1016/j.brainres.2014.05.028DOI Listing
July 2014

Loss of motor coordination in an aging mouse model.

Behav Brain Res 2014 Jul 25;267:119-25. Epub 2014 Mar 25.

Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, 600 Forbes Avenue, Pittsburgh, PA 15282, United States. Electronic address:

With age, there is an increase in motor deficits that leads to an increased incidence of slips and falls. As the elderly population continues to grow, there is a need for aging models and research that focus on behavioral deficits that occur with normal, non-diseased aging. The present study was designed to examine the appropriateness of C57Bl/6 male mice as aging animal models using the challenging beam and cylinder tests to measure motor coordination and spontaneous activity, respectively. Using young (2-4 mo), middle-aged (10-12 mo), and aged (22-24 mo) mice, we observed that aged C57Bl/6 male mice make more errors on the challenging beam task and take fewer hind limb steps as compared to young and middle-aged mice. Body weight and food intake were also measured to determine if these parameters were confounding factors in the interpretation of the behavioral data. Increases in body weight and food consumption were not observed in the oldest group that made the most errors. Together these data indicate that aged C57BL/6 mice display age-related motor deficits similar to those seen in humans and are an appropriate model of motor deficits that occur with age.
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http://dx.doi.org/10.1016/j.bbr.2014.03.032DOI Listing
July 2014

Role of ERK1, 2, and 5 in dopamine neuron survival during aging.

Neurobiol Aging 2014 Mar 23;35(3):669-79. Epub 2013 Oct 23.

Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, Pittsburgh, PA, USA. Electronic address:

Extracellular signal-regulated kinases (ERKs) 1, 2, and 5 have been shown to play distinct roles in proliferation, differentiation, and neuronal viability. In this study, we examined ERK1, 2, and 5 expression and activation in the substantia nigra (SN), striatum (STR), and ventral tegmental area (VTA) during aging. An age-related decrease in phosphorylated ERK5 was observed in the SN and STR, whereas an increase in total ERK1 was observed in all 3 regions. In primary cultures of the SN and VTA, inhibition of ERK5 but not ERK1 and 2 decreased dopamine neuronal viability significantly. These data suggest that ERK5 is essential for the basal survival of SN and VTA dopaminergic neurons. This is the first study to examine ERK1, 2, and 5 expression and activation in the SN, STR, and VTA during aging, and the relative roles of ERK1, 2, and 5 in basal survival of SN and VTA dopaminergic neurons. These data raise the possibility that a decline in ERK5 signaling may play a role in age-related impairments in dopaminergic function.
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http://dx.doi.org/10.1016/j.neurobiolaging.2013.09.031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3896870PMC
March 2014

L-DOPA reverses motor deficits associated with normal aging in mice.

Neurosci Lett 2011 Feb 25;489(1):1-4. Epub 2010 Nov 25.

Department of Pharmacology, Duquesne University, Pittsburgh, PA 15282, USA.

We wished to determine whether L-DOPA, a common treatment for the motor deficits in Parkinson's disease, could also reverse the motor deficits that occur during aging. We assessed motor performance in young (2-3 months) and old (20-21 months) male C57BL/6 mice using the challenge beam and cylinder tests. Prior to testing, mice were treated with L-DOPA or vehicle. Following testing, striatal tissue was analyzed for phenotypic markers of dopamine neurons: dopamine, dopamine transporter, and tyrosine hydroxylase. Although the dopaminergic markers were unchanged with age or L-DOPA treatment, L-DOPA reversed the motor deficits in the old animals such that their motor coordination was that of a young mice. These findings suggest that some of the locomotor deficits that accompany normal aging are responsive to L-DOPA treatment and may be due to subtle alterations in dopaminergic signaling.
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http://dx.doi.org/10.1016/j.neulet.2010.11.054DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3019282PMC
February 2011

Rapid activation of ERK by 6-hydroxydopamine promotes survival of dopaminergic cells.

J Neurosci Res 2008 Jan;86(1):108-17

Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.

Isoforms of the mitogen-activated protein kinase ERK have been implicated in both cell survival and cell death. In the present study we explored their role in cell viability in response to oxidative stress. Using the dopaminergic MN9D cell line, we determined that cell death occurred in a concentration-dependent manner after exposure to 6-hydroxydopamine (6-OHDA). The toxicity of 6-OHDA was mediated through generation of reactive oxygen species and was accompanied by a large increase in phosphorylated ERK1/2 but no significant increase in phosphorylated ERK5. 6-OHDA produced a distinct temporal pattern of ERK1/2 activation, with phosphorylated ERK1/2 peaks occurring after 10-15 min (25-fold increase) and 6-24 hr (13-fold increase). Inhibition of the early phosphorylated ERK1/2 peak with U0126 increased the generation of reactive oxygen species by 6-OHDA as well as 6-OHDA-induced toxicity, whereas inhibition of the late peak did not affect 6-OHDA-induced cell death. The time course of phosphorylation of the prosurvival protein CREB mimicked the temporal profile of ERK1/2 activation after 6-OHDA, and blocking the early phospho-ERK1/2 peak also abolished CREB activation. In contrast, activation of caspase-3 by 6-OHDA was delayed, occurring after about 6 hr, and this activation was increased by inhibition of the first phosphorylated ERK1/2 peak. These results suggest that the rapid activation of ERK1/2 in dopaminergic cells by oxidative stress serves as a self-protective response, reducing the content of reactive oxygen species and caspase-3 activity and increasing downstream ERK1/2 substrates.
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http://dx.doi.org/10.1002/jnr.21478DOI Listing
January 2008

Neuroprotective role of ERK1/2 and ERK5 in a dopaminergic cell line under basal conditions and in response to oxidative stress.

J Neurosci Res 2006 Nov;84(6):1367-75

Department of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15221, USA.

Loss of motor function in Parkinson's disease is due in part to degeneration of dopamine (DA) neurons. Pharmacological evidence suggests that the mitogen-activated protein kinase signaling pathways involving extracellular signal-regulated kinases (ERKs) play important roles in neuroprotection of DA neurons. However, the relative roles of the several ERK isoforms in the viability of DA neurons have not yet been determined. In the present study, we investigated the contributions of ERK5, as well as ERK1/2, to MN9D cell survival under basal conditions and in response to 6-hydroxydopamine (6-OHDA). We observed that U0126, an inhibitor of ERK activation, decreased basal survival of these cells. To differentiate between ERK1/2 and ERK5, cells were transfected with a dominant negative form of either ERK5 or MEK1, the upstream activator of ERK1/2. Transfection of MN9D cells with either dominant negative construct mimicked U0126, reducing cell survival. Moreover, transfection of the cells in such a way as to increase ERK5 or ERK1/2 activity inhibited 6-OHDA-induced cell death, although this effect was significant only in the case of ERK1/2 activation. These studies suggest that activations of ERK5 and ERK1/2 both promote basal DA cell survival and that ERK1/2 also protects DA cells from oxidative stress. These are the first studies to demonstrate a role for ERK5 in DA neuronal survival and to investigate the relative roles of ERK1/2 and ERK5 in basal DA survival and neuroprotection from oxidative stress.
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http://dx.doi.org/10.1002/jnr.21024DOI Listing
November 2006

Role of extracellular signal regulated kinase 5 in neuronal survival.

Authors:
Jane E Cavanaugh

Eur J Biochem 2004 Jun;271(11):2056-9

Department of Pharmacology, University of Pittsburgh, 13th Floor Biomedical Science Tower, 200 Lothrop Street, Pittsburgh, PA 15261, USA.

The newest member of the mitogen activated protein (MAP) kinase family of proteins, extracellular signal regulated kinase 5 (ERK5; also known as big-mitogen activated kinase 1 or BMK1) is widely expressed in many tissues including the brain. Although growth factor activation of ERK5 in non-neuronal cells has been shown to contribute to cell proliferation, differentiation and transformation, until recently no information was available on the role of ERK5 in neuronal survival. Recent data suggests that ERK5 is activated by neurotrophic factors in primary neuronal cells and plays an important role in neurotrophin mediated neuronal survival. These data also suggest that the mechanism of ERK5-mediated survival involves transcriptional regulation.
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http://dx.doi.org/10.1111/j.1432-1033.2004.04131.xDOI Listing
June 2004

ERK5 activation of MEF2-mediated gene expression plays a critical role in BDNF-promoted survival of developing but not mature cortical neurons.

Proc Natl Acad Sci U S A 2003 Jul 25;100(14):8532-7. Epub 2003 Jun 25.

Department of Environmental Health, University of Washington, Seattle, WA 98195-7234, USA.

Extracellular signal-regulated kinase 5 (ERK5) is a member of the mitogen-activated protein kinase family whose biological function in the CNS has not been defined. In contrast to ERK1 and ERK2, which are activated by neurotrophins (NTs), cAMP, and neuronal activity in cortical neurons, ERK5 is activated only by NTs. Here, we report that ERK5 expression is high in the brain during early embryonic development but declines as the brain matures to almost undetectable levels by postnatal day (P) 49. Interestingly, expression of a dominant-negative ERK5 blocked brain-derived neurotrophic factor protection against trophic withdrawal in primary cortical neurons cultured from embryonic day (E) 17 but not P0. Furthermore, expression of a dominant-negative ERK5 induced apoptosis in E17 but not P0 cortical neurons maintained in the presence of serum. We also present evidence that ERK5 protection of E17 cortical neurons may be mediated through myocyte enhancer factor 2-induced gene expression. These data suggest that ERK5 activation of myocyte enhancer factor 2-induced gene expression may play an important and novel role in the development of the CNS by mediating NT-promoted survival of embryonic neurons.
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http://dx.doi.org/10.1073/pnas.1332804100DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC166263PMC
July 2003

Duloxetine pharmacology: profile of a dual monoamine modulator.

CNS Drug Rev 2002 ;8(4):361-76

Departments of Pharmacology and Anesthesiology, Pennsylvania State College of Medicine, MC H078, 500 University Drive, Hershey, PA 17033-2390, USA.

Dysregulation within central monoaminergic systems is believed to underlie the pathology of depression. Drugs that selectively inhibit the reuptake of central monoamines have been used clinically to alleviate symptoms of depressive illnesses. Duloxetine, a novel compound currently under investigation for the treatment of depression, binds selectively with high affinity to both norepinephrine (NE) and serotonin (5-HT) transporters and lacks affinity for monoamine receptors within the central nervous system. It has been suggested that dual inhibition of monoamine reuptake processes may offer advantages over other antidepressants currently in use. In preclinical studies, duloxetine mimics many physiologic effects of antidepressants. Consistent with other antidepressants, duloxetine, by acute administration, elevates extracellular monoamine levels, while by chronic administration it does not alter basal monoamine levels. Like the selective serotonin reuptake inhibitor, fluoxetine, by microiontophoretic application, duloxetine inhibits neuronal cell firing. However, in comparison with fluoxetine, duloxetine is a more potent serotonin reuptake inhibitor. Furthermore, in behavioral experiments, duloxetine attenuates immobility in forced swim tests in animal models of depression to a greater extent than several other commonly used antidepressants. In a six-week open label uncontrolled study, duloxetine was evaluated in patients with a history of depression. Duloxetine was effective in treating depression as determined by marked reduction in Hamilton Depression Rating scores. Adverse effects reported during duloxetine treatment were minor and similar to those of other antidepressants. In an eight-week multicenter, double-blind, placebo-controlled study in patients with a major depressive disorder, duloxetine was effective as an antidepressant, particularly in patients with greater symptom severity. Only limited data are available regarding the pharmacokinetic profile of duloxetine in humans, although a half-life of 10 to 15 h has been reported. Studies conducted in healthy human subjects confirm the preclinical profile of duloxetine as an inhibitor of 5-HT and NE reuptake. Taken together, existing data suggest that duloxetine is a novel and effective antidepressant.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6741700PMC
http://dx.doi.org/10.1111/j.1527-3458.2002.tb00234.xDOI Listing
March 2003
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