1
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Dickmann CGF, McDonald AF, Huynh N, Rigopoulos A, Liu Z, Guo N, Osellame LD, Gorman MA, Parker MW, Gan HK, Scott AM, Ackermann U, Burvenich IJG, White JM. Bromodomain and extraterminal protein-targeted probe enables tumour visualisation in vivo using positron emission tomography. Chem Commun (Camb) 2023; 59:3126-3129. [PMID: 36809538 DOI: 10.1039/d2cc04813b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Bromodomain and extraterminal (BET) proteins, a family of epigenetic regulators, have emerged as important oncology drug targets. BET proteins have not been targeted for molecular imaging of cancer. Here, we report the development of a novel molecule radiolabelled with positron emitting fluorine-18, [18F]BiPET-2, and its in vitro and preclinical evaluation in glioblastoma models.
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Affiliation(s)
- Catherine G Fitzgerald Dickmann
- Bio21 Institute, The University of Melbourne, Parkville, VIC 3010, Australia. .,Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, and School of Cancer Medicine, La Trobe University, Heidelberg, Australia. .,Department of Molecular Imaging and Therapy, Austin Hospital, Heidelberg, Australia
| | - Alexander F McDonald
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, and School of Cancer Medicine, La Trobe University, Heidelberg, Australia. .,Department of Molecular Imaging and Therapy, Austin Hospital, Heidelberg, Australia
| | - Nhi Huynh
- Department of Molecular Imaging and Therapy, Austin Hospital, Heidelberg, Australia
| | - Angela Rigopoulos
- Department of Molecular Imaging and Therapy, Austin Hospital, Heidelberg, Australia
| | - Zhanqi Liu
- Department of Molecular Imaging and Therapy, Austin Hospital, Heidelberg, Australia
| | - Nancy Guo
- Department of Molecular Imaging and Therapy, Austin Hospital, Heidelberg, Australia
| | - Laura D Osellame
- Department of Molecular Imaging and Therapy, Austin Hospital, Heidelberg, Australia
| | - Michael A Gorman
- Bio21 Institute, The University of Melbourne, Parkville, VIC 3010, Australia.
| | - Michael W Parker
- Bio21 Institute, The University of Melbourne, Parkville, VIC 3010, Australia. .,ACRF Facility for Innovative Cancer Drug Discovery, Bio21 Institute, The University of Melbourne, Parkville, VIC 3010, Australia.,ACRF Rational Drug Discovery Centre, St. Vincent's Institute of Medical Research, VIC 3065, Australia
| | - Hui K Gan
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, and School of Cancer Medicine, La Trobe University, Heidelberg, Australia.
| | - Andrew M Scott
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, and School of Cancer Medicine, La Trobe University, Heidelberg, Australia. .,Department of Molecular Imaging and Therapy, Austin Hospital, Heidelberg, Australia.,Faculty of Medicine, University of Melbourne, Parkville, Australia
| | - Uwe Ackermann
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, and School of Cancer Medicine, La Trobe University, Heidelberg, Australia. .,Department of Molecular Imaging and Therapy, Austin Hospital, Heidelberg, Australia
| | - Ingrid J G Burvenich
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, and School of Cancer Medicine, La Trobe University, Heidelberg, Australia.
| | - Jonathan M White
- Bio21 Institute, The University of Melbourne, Parkville, VIC 3010, Australia.
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2
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Chen H, Emami E, Kauffmann C, Rompré P, Almeida F, Schmittbuhl M, van der Stelt P, Ge S, Lavigne G, Huynh N. Airway Phenotypes and Nocturnal Wearing of Dentures in Elders with Sleep Apnea. J Dent Res 2023; 102:263-269. [PMID: 36333889 DOI: 10.1177/00220345221133278] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The objective of this study was to examine to what extent the anatomic characteristics of the upper airway can influence the effect of nocturnal wearing of dentures on the sleep of edentulous elders with untreated sleep apnea. This study used the data from a randomized crossover clinical trial and an exploratory approach to address its objectives. Cone beam computed tomography scans of 65 edentulous individuals (female, n = 37; male, n = 28; mean ± SD age, 74.54 ± 6.42 y) with untreated obstructive sleep apnea (OSA) were used to identify anatomic variables. Polysomnography data were collected by means of one portable overnight recording. The respiratory variable values, including apnea-hypopnea index (AHI), with and without denture worn during sleep were used to calculate the change. Statistical analyses included multiple linear regressions, cluster analysis, and binary logistic regressions. A receiver operator characteristic curve was used to illustrate the accuracy of the statistical model. The regression model explained 15.8% (R2) of AHI change. An increase in the lateral dimension of the minimum cross-sectional area was associated with a decrease in AHI, oxygen desaturation index, and respiratory arousal index changes (P ≤ 0.041). Furthermore, an increase in the length of the hypopharynx was associated with an increase in AHI and oxygen desaturation index changes (P ≤ 0.027). An increase in the lateral dimension of the minimum cross-sectional area of the upper airway was associated with a decreased likelihood of being in the group having a worsened AHI (odds ratio = 0.85; 95% CI, 0.76 to 0.95; P = 0.006). An increase in the length of the oropharynx was associated with an increased likelihood of having increased AHI (odds ratio = 1.10; 95% CI, 1.01 to 1.20; P = 0.026). The nocturnal aggravation of respiratory variables in edentulous individuals with OSA who wear dentures at night can be linked to certain anatomic characteristics of the upper airway. Replication of these findings may open novel avenues for personalized advice regarding nocturnal wearing of dentures in edentulous individuals with OSA (ClinicalTrials.gov: NCT01868295).
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Affiliation(s)
- H Chen
- Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China.,Faculty of Dental Medicine, Université de Montréal, Montreal, Canada
| | - E Emami
- Faculty of Dental Medicine and Oral Health Sciences, McGill University, Montreal, Canada
| | - C Kauffmann
- Centre hospitalier de l'Université de Montréal, Montreal, Canada
| | - P Rompré
- Faculty of Dental Medicine, Université de Montréal, Montreal, Canada
| | - F Almeida
- Faculty of Dentistry, University of British Columbia, Vancouver, Canada
| | - M Schmittbuhl
- Faculty of Dental Medicine, Université de Montréal, Montreal, Canada.,Centre hospitalier de l'Université de Montréal, Montreal, Canada
| | - P van der Stelt
- Academic Centre for Dentistry Amsterdam, Amsterdam, the Netherlands
| | - S Ge
- Department of Orthodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan, China
| | - G Lavigne
- Faculty of Dental Medicine, Université de Montréal, Montreal, Canada.,Centre hospitalier de l'Université de Montréal, Montreal, Canada
| | - N Huynh
- Faculty of Dental Medicine, Université de Montréal, Montreal, Canada.,Centre hospitalier de l'Université de Montréal, Montreal, Canada
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Lee NH, Ma Y, Ang CS, Dumesny C, Huynh N, Yang Y, Wang K, Nikfarjam M, He H. CXCL5 knockdown attenuated gemcitabine resistance of pancreatic cancer through regulation of cancer cells and tumour stroma. Am J Transl Res 2023; 15:2676-2689. [PMID: 37193135 PMCID: PMC10182491] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 12/28/2022] [Indexed: 05/18/2023]
Abstract
Chemoresistance is one of the major causes to the poor prognosis of pancreatic cancer (PC). Gemcitabine alone and gemcitabine-based therapies are mostly used for the treatment of PC. Gemcitabine resistance becomes the focus of chemotherapy. C-X-C motif chemokine 5 (CXCL5), a member of the C-X-C chemokine family, acts through C-X-C chemokine receptor type 2 (CXCR2). A high level of CXCL5 is associated with worse prognosis in PC patients and increased suppressive immune cell infiltration. Increased expression of CXCL5 is also found in gemcitabine-treated PC cells. To investigate the role of CXCL5 in PC response to gemcitabine, CXCL5 knockdown (KD) PC cells were generated and its effect on cancer cell response to gemcitabine in vitro and in vivo was studied. The mechanisms involved were also explored by determining the changes in the tumour microenvironment (TME) and protein profile of the CXCL5 KD cells using immune-staining and proteomic analysis. The results showed that CXCL5 expression were increased in all PC cell lines tested and in gemcitabine-resistant tumour tissue, that CXCL5 KD suppressed PC growth and sensitized PC cell response to gemcitabine and that CXCL5 KD stimulated the activation of stromal cells in TME. We conclude that CXCL5 promotes gemcitabine resistance by affecting TME and cancer cells.
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Affiliation(s)
- Nien-Hung Lee
- Department of Surgery, University of Melbourne, Austin HealthHeidelberg, Victoria, Australia
| | - Yi Ma
- Department of Surgery, University of Melbourne, Austin HealthHeidelberg, Victoria, Australia
| | - Ching-Seng Ang
- Bio-21 Institute, University of MelbourneParkville, Victoria, Australia
| | - Chelsea Dumesny
- Department of Surgery, University of Melbourne, Austin HealthHeidelberg, Victoria, Australia
| | - Nhi Huynh
- Department of Surgery, University of Melbourne, Austin HealthHeidelberg, Victoria, Australia
- Tumour Targeting Laboratory, Level 5, ONJCRIHeidelberg, Victoria, Australia
| | - Yang Yang
- Department of Surgery, University of Melbourne, Austin HealthHeidelberg, Victoria, Australia
| | - Kai Wang
- Department of Surgery, University of Melbourne, Austin HealthHeidelberg, Victoria, Australia
| | - Mehrdad Nikfarjam
- Department of Surgery, University of Melbourne, Austin HealthHeidelberg, Victoria, Australia
| | - Hong He
- Department of Surgery, University of Melbourne, Austin HealthHeidelberg, Victoria, Australia
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Gilbert C, Arcache P, Pliska B, Almeida F, Rompre P, Huynh N. The effectiveness of morning repositioning splints following mandibular advancement device use – a pilot study. Sleep Med 2022. [DOI: 10.1016/j.sleep.2022.05.176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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5
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Choi B, Lasica M, Huynh N, Sirdesai S, Nagarethinam M, Ting S, Cooke J, Hare J, Gibbs S. The Increasing Recognition of Transthyretin Cardiac Amyloidosis (ATTR-CA): Patient Characteristics and Survival in the Australian Context. Heart Lung Circ 2022. [DOI: 10.1016/j.hlc.2022.06.133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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6
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Burvenich IJG, Goh YW, Guo N, Gan HK, Rigopoulos A, Cao D, Liu Z, Ackermann U, Wichmann CW, McDonald AF, Huynh N, O'Keefe GJ, Gong SJ, Scott FE, Li L, Geng W, Zutshi A, Lan Y, Scott AM. Radiolabelling and preclinical characterization of 89Zr-Df-radiolabelled bispecific anti-PD-L1/TGF-βRII fusion protein bintrafusp alfa. Eur J Nucl Med Mol Imaging 2021; 48:3075-3088. [PMID: 33608805 DOI: 10.1007/s00259-021-05251-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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: 07/29/2020] [Accepted: 02/08/2021] [Indexed: 12/01/2022]
Abstract
PURPOSE Τhis study aimed to optimize the 89Zr-radiolabelling of bintrafusp alfa investigational drug product and controls, and perform the in vitro and in vivo characterization of 89Zr-Df-bintrafusp alfa and 89Zr-Df-control radioconjugates. METHODS Bintrafusp alfa (anti-PD-L1 human IgG1 antibody fused to TGF-β receptor II (TGF-βRII), avelumab (anti-PD-L1 human IgG1 control antibody), isotype control (mutated inactive anti-PD-L1 IgG1 control antibody), and trap control (mutated inactive anti-PD-L1 human IgG1 fused to active TGF-βRII) were chelated with p-isothiocyanatobenzyl-desferrioxamine (Df). After radiolabelling with zirconium-89 (89Zr), radioconjugates were assessed for radiochemical purity, immunoreactivity, antigen binding affinity, and serum stability in vitro. In vivo biodistribution and imaging studies were performed with PET/CT to identify and quantitate 89Zr-Df-bintrafusp alfa tumour uptake in a PD-L1/TGF-β-positive murine breast cancer model (EMT-6). Specificity of 89Zr-Df-bintrafusp alfa was assessed via a combined biodistribution and imaging experiment in the presence of competing cold bintrafusp alfa (1 mg/kg). RESULTS Nanomolar affinities for PD-L1 were achieved with 89Zr-Df-bintrafusp alfa and 89Zr-avelumab. Biodistribution and imaging studies in PD-L1- and TGF-β-positive EMT-6 tumour-bearing BALB/c mice demonstrated the biologic similarity of 89Zr-Df-bintrafusp alfa and 89Zr-avelumab indicating the in vivo distribution pattern of bintrafusp alfa is driven by its PD-L1 binding arm. Competition study with 1 mg of unlabelled bintrafusp alfa or avelumab co-administered with trace dose of 89Zr-labelled bintrafusp alfa demonstrated the impact of dose and specificity of PD-L1 targeting in vivo. CONCLUSION Molecular imaging of 89Zr-Df-bintrafusp alfa biodistribution was achievable and allows non-invasive quantitation of tumour uptake of 89Zr-Df-bintrafusp alfa, suitable for use in bioimaging clinical trials in cancer patients.
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Affiliation(s)
- Ingrid Julienne Georgette Burvenich
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia.,School of Cancer Medicine, La Trobe University, Melbourne, Australia
| | - Yit Wooi Goh
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia
| | - Nancy Guo
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia
| | - Hui Kong Gan
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia.,School of Cancer Medicine, La Trobe University, Melbourne, Australia
| | - Angela Rigopoulos
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia.,School of Cancer Medicine, La Trobe University, Melbourne, Australia
| | - Diana Cao
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia.,School of Cancer Medicine, La Trobe University, Melbourne, Australia
| | - Zhanqi Liu
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia.,School of Cancer Medicine, La Trobe University, Melbourne, Australia
| | - Uwe Ackermann
- School of Cancer Medicine, La Trobe University, Melbourne, Australia.,Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Australia.,Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Christian Werner Wichmann
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia.,School of Cancer Medicine, La Trobe University, Melbourne, Australia
| | - Alexander Franklin McDonald
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia.,School of Cancer Medicine, La Trobe University, Melbourne, Australia
| | - Nhi Huynh
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia
| | - Graeme Joseph O'Keefe
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Australia.,Department of Medicine, University of Melbourne, Melbourne, Australia
| | - Sylvia Jie Gong
- Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Australia.,School of Engineering and Mathematical Sciences, La Trobe University, Melbourne, Australia
| | - Fiona Elizabeth Scott
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia.,School of Cancer Medicine, La Trobe University, Melbourne, Australia
| | - Linghui Li
- EMD Serono Research & Development Institute, Inc., a business of Merck KGaA, Darmstadt, Germany, Billerica, MA, USA
| | - Wanping Geng
- EMD Serono Research & Development Institute, Inc., a business of Merck KGaA, Darmstadt, Germany, Billerica, MA, USA
| | - Anup Zutshi
- EMD Serono Research & Development Institute, Inc., a business of Merck KGaA, Darmstadt, Germany, Billerica, MA, USA
| | - Yan Lan
- EMD Serono Research & Development Institute, Inc., a business of Merck KGaA, Darmstadt, Germany, Billerica, MA, USA
| | - Andrew Mark Scott
- Tumour Targeting Laboratory, Olivia Newton-John Cancer Research Institute, 145 Studley Road, Heidelberg, Melbourne, Victoria, 3084, Australia. .,School of Cancer Medicine, La Trobe University, Melbourne, Australia. .,Department of Molecular Imaging and Therapy, Austin Health, Melbourne, Australia. .,Department of Medicine, University of Melbourne, Melbourne, Australia.
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7
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Povitz M, Bansback N, Fenton M, Almeida F, Ratycz D, Huynh N, Ayas N, Chiu J, Pendharkar S. Workplace and driving consequences of sleepiness in Canadians with obstructive sleep apnea: results of a market research survey. Sleep Med 2019. [DOI: 10.1016/j.sleep.2019.11.860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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8
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Lavigne G, Herrero Babiloni A, Beetz G, Dal Fabbro C, Sutherland K, Huynh N, Cistulli P. Critical Issues in Dental and Medical Management of Obstructive Sleep Apnea. J Dent Res 2019; 99:26-35. [DOI: 10.1177/0022034519885644] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
This critical review focuses on obstructive sleep apnea (OSA) and its management from a dental medicine perspective. OSA is characterized by ≥10-s cessation of breathing (apnea) or reduction in airflow (hypopnea) ≥5 times per hour with a drop in oxygen and/or rise in carbon dioxide. It can be associated with sleepiness and fatigue, impaired mood and cognition, cardiometabolic complications, and risk for transportation and work accidents. Although sleep apnea is diagnosed by a sleep physician, its management is interdisciplinary. The dentist’s role includes 1) screening patients for OSA risk factors (e.g., retrognathia, high arched palate, enlarged tonsils or tongue, enlarged tori, high Mallampati score, poor sleep, supine sleep position, obesity, hypertension, morning headache or orofacial pain, bruxism); 2) referring to an appropriate health professional as indicated; and 3) providing oral appliance therapy followed by regular dental and sleep medical follow-up. In addition to the device features and provider expertise, anatomic, behavioral, demographic, and neurophysiologic characteristics can influence oral appliance effectiveness in managing OSA. Therefore, OSA treatment should be tailored to each patient individually. This review highlights some of the putative action mechanisms related to oral appliance effectiveness and proposes future research directions.
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Affiliation(s)
- G.J. Lavigne
- Faculté de médicine dentaire, Université de Montréal, Montréal, Canada
- Research Center, CIUSSS du Nord-de-l’Île-de-Montréal, Montréal, Canada
- Division of Experimental Medicine, McGill University, Montréal, Canada
| | - A. Herrero Babiloni
- Faculté de médicine dentaire, Université de Montréal, Montréal, Canada
- Research Center, CIUSSS du Nord-de-l’Île-de-Montréal, Montréal, Canada
- Division of Experimental Medicine, McGill University, Montréal, Canada
| | - G. Beetz
- Research Center, CIUSSS du Nord-de-l’Île-de-Montréal, Montréal, Canada
| | | | - K. Sutherland
- Charles Perkins Centre and Sydney Medical School, University of Sydney, and Royal North Shore Hospital, Sydney, Australia
| | - N. Huynh
- Faculté de médicine dentaire, Université de Montréal, Montréal, Canada
| | - P.A. Cistulli
- Charles Perkins Centre and Sydney Medical School, University of Sydney, and Royal North Shore Hospital, Sydney, Australia
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9
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Wang K, Huynh N, Wang X, Pajic M, Parkin A, Man J, Baldwin GS, Nikfarjam M, He H. PAK inhibition by PF-3758309 enhanced the sensitivity of multiple chemotherapeutic reagents in patient-derived pancreatic cancer cell lines. Am J Transl Res 2019; 11:3353-3364. [PMID: 31312349 PMCID: PMC6614655] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/06/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND/OBJECTIVE Pancreatic ductal adenocarcinoma (PDA) remains the most lethal malignancy due to lack of an effective treatment. P21-activated kinases (PAKs) play a key role not only in cell proliferation and migration, but also in mediating chemo-resistance in PDA. The aim of this study was to investigate the combined effect of a PAK inhibitor PF-3758309 with multiple chemotherapeutic reagents on a panel of patient-derived PDA cell lines, and potential mechanisms involved. METHODS Cells were treated with PF-3758309 plus or minus gemcitabine, 5-fluorouracil (5-FU) or abraxane, and cell growth was determined using a cell proliferation assay kit. Protein expression profiles were measured by Western blot. PDA cells were subcutaneously injected into the flanks of SCID mice which were then treated with saline, gemcitabine, PF-3758309, gemcitabine plus PF-3758309 or abraxane. Tumour growth was measured by volume and weight. RESULTS PAK1 was correlated with CK19 expression, and PAK4 with α-SMA and palladin expression. Combination of PF-3758309 with 5-FU, gemcitabine or abraxane further suppressed cell growth of patient-derived PDA cell lines in vitro. The combination of PF-3758309 with gemcitabine maximally inhibited tumour growth in vivo by suppressing cell proliferation. PF-3758309 inhibited the expression of HIF-1α, palladin and α-SMA both in vitro and in vivo. CONCLUSIONS PAK inhibitor PF-3758309 can enhance anti-tumour effects of multiple chemotherapeutic reagents on a panel of patient-derived PDA cell lines. Combination of PF-3758309 with gemcitabine achieves comparable efficacy to combination of gemcitabine with abraxane, and thus provides a potential targeted therapy in the management of PDA.
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Affiliation(s)
- Kai Wang
- Department of Surgery, University of Melbourne, Austin HealthStudley Road, Heidelberg, Victoria 3084, Australia
| | - Nhi Huynh
- Department of Surgery, University of Melbourne, Austin HealthStudley Road, Heidelberg, Victoria 3084, Australia
| | - Xiao Wang
- Department of Surgery, University of Melbourne, Austin HealthStudley Road, Heidelberg, Victoria 3084, Australia
| | - Marina Pajic
- The Kinghorn Cancer Centre, The Garvan Institute of Medical Research384 Victoria St, Darlinghurst, Sydney, NSW 2010, Australia
- St Vincent’s Clinical School, Faculty of Medicine, University of NSWAustralia
| | - Ashleigh Parkin
- The Kinghorn Cancer Centre, The Garvan Institute of Medical Research384 Victoria St, Darlinghurst, Sydney, NSW 2010, Australia
| | - Jennifer Man
- The Kinghorn Cancer Centre, The Garvan Institute of Medical Research384 Victoria St, Darlinghurst, Sydney, NSW 2010, Australia
| | - Graham S Baldwin
- Department of Surgery, University of Melbourne, Austin HealthStudley Road, Heidelberg, Victoria 3084, Australia
| | - Mehrdad Nikfarjam
- Department of Surgery, University of Melbourne, Austin HealthStudley Road, Heidelberg, Victoria 3084, Australia
| | - Hong He
- Department of Surgery, University of Melbourne, Austin HealthStudley Road, Heidelberg, Victoria 3084, Australia
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Forehead H, Huynh N. Review of modelling air pollution from traffic at street-level - The state of the science. Environ Pollut 2018; 241:775-786. [PMID: 29908501 DOI: 10.1016/j.envpol.2018.06.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 06/05/2018] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
Traffic emissions are a complex and variable cocktail of toxic chemicals. They are the major source of atmospheric pollution in the parts of cities where people live, commute and work. Reducing exposure requires information about the distribution and nature of emissions. Spatially and temporally detailed data are required, because both the rate of production and the composition of emissions vary significantly with time of day and with local changes in wind, traffic composition and flow. Increasing computer processing power means that models can accept highly detailed inputs of fleet, fuels and road networks. The state of the science models can simulate the behaviour and emissions of all the individual vehicles on a road network, with resolution of a second and tens of metres. The chemistry of the simulated emissions is also highly resolved, due to consideration of multiple engine processes, fuel evaporation and tyre wear. Good results can be achieved with both commercially available and open source models. The extent of a simulation is usually limited by processing capacity; the accuracy by the quality of traffic data. Recent studies have generated real time, detailed emissions data by using inputs from novel traffic sensing technologies and data from intelligent traffic systems (ITS). Increasingly, detailed pollution data is being combined with spatially resolved demographic or epidemiological data for targeted risk analyses.
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Affiliation(s)
- H Forehead
- SMART Infrastructure Facility, University of Wollongong, Wollongong, NSW, Australia.
| | - N Huynh
- SMART Infrastructure Facility, University of Wollongong, Wollongong, NSW, Australia
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11
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Gomes T, Huynh N, Emami E. 0717 Comparaison Of Self-reported Objectives Sleep Measures In Elderly Population With Sleep Apnea. Sleep 2018. [DOI: 10.1093/sleep/zsy061.716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- T Gomes
- University of Montreal, Montréal, QC, CANADA
| | - N Huynh
- University of Montreal, Montréal, QC, CANADA
| | - E Emami
- University of Montreal, Montréal, QC, CANADA
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12
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De Blasio M, Huynh N, Dubrana L, Prakoso D, Qin C, Tate M, Deo M, Oseghale O, Kiriazis H, Du X, Ritchie R. Progression of Markers Contributing to Cardiomyopathy in a Mouse Model of Type 1 Diabetes. Heart Lung Circ 2018. [DOI: 10.1016/j.hlc.2018.06.179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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13
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Wang K, Huynh N, Wang X, Baldwin G, Nikfarjam M, He H. Inhibition of p21 activated kinase enhances tumour immune response and sensitizes pancreatic cancer to gemcitabine. Int J Oncol 2017; 52:261-269. [PMID: 29115428 DOI: 10.3892/ijo.2017.4193] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 10/18/2017] [Indexed: 12/17/2022] Open
Abstract
Pancreatic ductal adenocarcinoma (PDA) is one of the major types of cancer that exhibit high mortality worldwide because of the late diagnosis and the lack of effective treatment. Immunotherapy appears to be ineffective in PDA treatment due to the existence of a unique immune-suppressive microenvironment in PDA. Gemcitabine-based therapy is still the most commonly used chemotherapy to treat PDA patients with only marginal increased survival rates. This prompted us to continue the search for more effective therapy for PDA treatment. The effects of p21 activated kinases (PAKs) on tumour immune response and gemcitabine response were examined in PDA. An orthotopic murine PDA model, in which pancreatic cancer cells were injected to the tail of pancreas, was used. The mice were treated with PAK inhibitor, PF‑3758309, plus or minus gemcitabine. Tumour growth was measured by volume and weight. Tumour immune response was determined by flow cytometry analysis of splenic cells and immunohistochemical staining of intratumoural lymphocytes. Inhibition of PAKs by PF‑3758309, not only suppressed tumour growth, but also stimulated tumour immune response by increasing the numbers of splenic and intratumoural T lymphocytes. Furthermore, inhibition of PAKs decreased PDA cell growth synergistically with gemcitabine in vitro and in vivo. The dual effects of inhibition of PAKs make PAK-targeted therapy more potent for the treatment of PDA. The combination of PAK inhibitors with gemcitabine may be a more effective therapeutic approach in PDA treatment.
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Affiliation(s)
- Kai Wang
- Department of Surgery, University of Melbourne, Austin Health, Heidelberg, Victoria 3048, Australia
| | - Nhi Huynh
- Department of Surgery, University of Melbourne, Austin Health, Heidelberg, Victoria 3048, Australia
| | - Xiao Wang
- Department of Surgery, University of Melbourne, Austin Health, Heidelberg, Victoria 3048, Australia
| | - Graham Baldwin
- Department of Surgery, University of Melbourne, Austin Health, Heidelberg, Victoria 3048, Australia
| | - Mehrdad Nikfarjam
- Department of Surgery, University of Melbourne, Austin Health, Heidelberg, Victoria 3048, Australia
| | - Hong He
- Department of Surgery, University of Melbourne, Austin Health, Heidelberg, Victoria 3048, Australia
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Huynh N, Wang K, Yim M, Dumesny CJ, Sandrin MS, Baldwin GS, Nikfarjam M, He H. Depletion of p21-activated kinase 1 up-regulates the immune system of APC ∆14/+ mice and inhibits intestinal tumorigenesis. BMC Cancer 2017. [PMID: 28629331 PMCID: PMC5477105 DOI: 10.1186/s12885-017-3432-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [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] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND P21-activated kinase 1 (PAK1) stimulates growth and metastasis of colorectal cancer (CRC) through activation of multiple signalling pathways. Up-regulation of CRC stem cell markers by PAK1 also contributes to the resistance of CRC to 5-fluorouracil. The aim of this study was to investigate the effect of PAK1 depletion and inhibition on the immune system and on intestinal tumour formation in APC∆14/+ mice. METHODS The PAK1 KO APC∆14/+ mice were generated by cross-breeding of PAK1 KO mice with APC∆14/+ mice. Splenic lymphocytes were analysed by flow cytometry, and immunohistochemical staining. The numbers of intestinal tumours were counted. Blood cells were also counted. RESULTS Compared to APC+/+ mice, the numbers of both T- and B- lymphocytes were reduced in the spleen of APC∆14/+ mice. Depletion of PAK1 in APC∆14/+ mice increased the numbers of splenic T- and B- lymphocytes and decreased the numbers of intestinal tumours. Treatment of APC∆14/+ mice with PF-3758309, a PAK inhibitor reduced the numbers of intestinal tumours and increased the numbers of blood lymphocytes. CONCLUSION Depletion of active PAK1 up-regulates the immune system of APC∆14/+ mice and suppresses intestinal tumour development. These observations suggest an important role for PAK1 in the immune response to tumours.
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Affiliation(s)
- Nhi Huynh
- Department of Surgery, University of Melbourne, Austin Health, Studley Rd, Heidelberg, VIC, 3084, Australia
| | - Kai Wang
- Department of Surgery, University of Melbourne, Austin Health, Studley Rd, Heidelberg, VIC, 3084, Australia
| | - Mildred Yim
- Department of Surgery, University of Melbourne, Austin Health, Studley Rd, Heidelberg, VIC, 3084, Australia
| | - Chelsea J Dumesny
- Department of Surgery, University of Melbourne, Austin Health, Studley Rd, Heidelberg, VIC, 3084, Australia
| | - Mauro S Sandrin
- Department of Surgery, University of Melbourne, Austin Health, Studley Rd, Heidelberg, VIC, 3084, Australia
| | - Graham S Baldwin
- Department of Surgery, University of Melbourne, Austin Health, Studley Rd, Heidelberg, VIC, 3084, Australia
| | - Mehrdad Nikfarjam
- Department of Surgery, University of Melbourne, Austin Health, Studley Rd, Heidelberg, VIC, 3084, Australia
| | - Hong He
- Department of Surgery, University of Melbourne, Austin Health, Studley Rd, Heidelberg, VIC, 3084, Australia.
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15
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COHEN LEVY JM, Rompré P, Quintal M, Arcand P, Abela A, Almeida F, Huynh N. 0885 OROFACIAL MORPHOLOGY AND DYSFUNCTIONS IN CHILDREN WITH PERSISTANT SLEEP DISORDERED BREATHING LONG-TERM AFTER ADENOID AND/OR TONSILS REMOVAL. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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16
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Huynh N, Shulkes A, Baldwin G, He H. Up-regulation of stem cell markers by P21-activated kinase 1 contributes to 5-fluorouracil resistance of colorectal cancer. Cancer Biol Ther 2016; 17:813-23. [PMID: 27260988 DOI: 10.1080/15384047.2016.1195045] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cancer stem cells (CSC) are tumorigenic and resistant to chemotherapy. In colorectal cancer (CRC), CSCs have been identified by the expression of specific markers, including CD44, Bmi1 and Nanog. Although p21-activated kinase 1 (PAK1), acting downstream of Ras, stimulates Wnt/β-catenin signaling and is known to play an important role in CRC development and progression, the role of PAK1 in the expression of CSC markers has not previously been investigated. The effect of PAK1 over-expression, knockdown or inhibition on the expression or alteration (in the case of CD44) of CSC markers in human CRC cell lines was measured by immunofluorescence and Western blotting. The effect of PAK1 modulation on tumorigenesis, and on resistance to treatment with 5-fluorouracil (5-FU), was measured by sphere formation in vitro and by growth of xenografted tumors in vivo. The results show that PAK1 activity correlated with the expression of CSC markers and the CD44 isoform profile, and with tumor growth both in vitro and in vivo. Furthermore PAK overexpression partially overcame the inhibition of CRC growth by 5-FU, and PAK inhibition was synergistic with 5-FU treatment. Our findings lay the foundation for a combination therapy in which PAK1 inhibitors targeting CSCs may be combined with conventional 5-FU-based chemotherapy for the treatment of CRC.
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Affiliation(s)
- Nhi Huynh
- a Department of Surgery , University of Melbourne, Austin Health , Heidelberg , Victoria , Australia
| | - Arthur Shulkes
- a Department of Surgery , University of Melbourne, Austin Health , Heidelberg , Victoria , Australia
| | - Graham Baldwin
- a Department of Surgery , University of Melbourne, Austin Health , Heidelberg , Victoria , Australia
| | - Hong He
- a Department of Surgery , University of Melbourne, Austin Health , Heidelberg , Victoria , Australia
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17
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Yeo D, Huynh N, Beutler JA, Baldwin GS, He H, Nikfarjam M. Glaucarubinone Combined with Gemcitabine Improves Pancreatic Cancer Survival in an Immunocompetent Orthotopic Murine Model. J INVEST SURG 2016; 29:366-372. [PMID: 27027695 DOI: 10.3109/08941939.2016.1160167] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Pancreatic cancer continues to have a poor survival rate with an urgent need for improved treatments. Glaucarubinone, a natural product first isolated from the seeds of the tree Simarouba glauca, has recently been recognized as having anti-cancer properties that may be particularly applicable to pancreatic cancer. METHODS The effect of glaucarubinone on the growth and migration of murine pancreatic cancer cells was assessed by 3H-thymidine incorporation assay. The survival impact of glaucarubinone alone and in combination with gemcitabine chemotherapy was assessed using an immunocompetent orthotopic murine model of pancreatic cancer. RESULTS Glaucarubinone inhibited the growth of the murine pancreatic cancer cell lines LM-P and PAN02. Treatment with either glaucarubinone or gemcitabine reduced proliferation in vitro and the combination was synergistic. The combination treatment improved survival two-fold compared to gemcitabine treatment alone (p = 0.046) in PAN02 cells. CONCLUSIONS The synergistic inhibition by glaucarubinone and gemcitabine observed in vitro and the improved survival in vivo suggest that glaucarubinone may be a useful adjunct to current chemotherapy regimens.
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Affiliation(s)
- Dannel Yeo
- a Department of Surgery , University of Melbourne, Austin Health , Melbourne , Victoria , Australia
| | - Nhi Huynh
- a Department of Surgery , University of Melbourne, Austin Health , Melbourne , Victoria , Australia
| | - John A Beutler
- b Molecular Targets Laboratory, National Cancer Institute , Frederick , MD
| | - Graham S Baldwin
- a Department of Surgery , University of Melbourne, Austin Health , Melbourne , Victoria , Australia
| | - Hong He
- a Department of Surgery , University of Melbourne, Austin Health , Melbourne , Victoria , Australia
| | - Mehrdad Nikfarjam
- a Department of Surgery , University of Melbourne, Austin Health , Melbourne , Victoria , Australia
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18
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Huynh N, VonMoss L, Smith D, Rahman I, Felemban MF, Zuo J, Rody WJ, McHugh KP, Holliday LS. Characterization of Regulatory Extracellular Vesicles from Osteoclasts. J Dent Res 2016; 95:673-9. [PMID: 26908631 DOI: 10.1177/0022034516633189] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Extracellular vesicles (EVs), which include exosomes and ectosomes/microvesicles, have emerged as important intercellular regulators. EVs can interact with surface receptors of target cells and can transport luminal components, including messenger RNAs (mRNAs), microRNAs, and enzymes, to the cytosol of the target cell. Here, we show that hematopoietic cells grown in culture shed exosome-like EVs as they differentiate from preosteoclasts into osteoclasts. These EVs were between 25 and 120 nm (mean, 40 nm) in diameter determined by transmission electron microscopy. The exosome-associated markers CD63 and EpCAM were enriched in the isolated EVs while markers of Golgi and endoplasmic reticulum were not detected. Treatment of isolated hematopoietic cells with EVs did not affect their receptor activator of nuclear factor κB-ligand (RANKL)-stimulated differentiation into osteoclasts. However, EVs from osteoclast precursors promoted 1,25-dihydroxyvitamin D3-dependent osteoclast formation in whole mouse marrow cultures, and EVs from osteoclast-enriched cultures inhibited osteoclastogenesis in the same cultures. These data suggested that osteoclast-derived EVs are paracrine regulators of osteoclastogenesis. EVs from mature osteoclasts contained receptor activator of nuclear factor κB (RANK). Immunogold labeling showed RANK was enriched in 1 in every 32 EVs isolated from osteoclast-enriched cultures. Depletion of RANK-rich EVs relieved the ability of osteoclast-derived EVs to inhibit osteoclast formation in 1,25-dihydroxyvitamin D3-stimulated marrow cultures. In summary, we show for the first time that EVs released by osteoclasts are novel regulators of osteoclastogenesis. Our data suggest that RANK in EVs may be mechanistically linked to the inhibition of osteoclast formation. RANK present in EVs may function by competitively inhibiting the stimulation of RANK on osteoclast surfaces by RANKL similar to osteoprotegerin. RANK-rich EVs may also take advantage of the RANK/RANKL interaction to target RANK-rich EVs to RANKL-bearing cells for the delivery of other regulatory molecules.
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Affiliation(s)
- N Huynh
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - L VonMoss
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - D Smith
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - I Rahman
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - M F Felemban
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - J Zuo
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - W J Rody
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - K P McHugh
- Department of Periodontics, University of Florida College of Dentistry, Gainesville, FL, USA
| | - L S Holliday
- Department of Orthodontics, University of Florida College of Dentistry, Gainesville, FL, USA Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, FL, USA
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Huynh N, Liu KH, Yim M, Shulkes A, Baldwin GS, He H. Demonstration and biological significance of a gastrin-P21-activated kinase 1 feedback loop in colorectal cancer cells. Physiol Rep 2014; 2:2/6/e12048. [PMID: 24963032 PMCID: PMC4208650 DOI: 10.14814/phy2.12048] [Citation(s) in RCA: 3] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Gastrins, including amidated gastrin17 and glycine-extended gastrin17, are important growth factors in colorectal cancer (CRC). The p21-activated kinase 1 (PAK1) plays key roles in cellular processes including proliferation, survival, and motility, and in cell transformation and tumor progression. PAK1 expression increases with the progression of CRC, and knockdown of PAK1 blocks CRC cell growth and metastasis both in vitro and in vivo. The aim of this study was to determine the interaction between PAK1 and gastrins in CRC cells. PAK1 expression and activation were assayed by Western blots, and concentrations of gastrin mRNA and peptides by real-time PCR and radioimmunoassay, respectively. Proliferation of CRC cells was measured by (3)H-thymidine incorporation, and vascular endothelial growth factor : VEGF) secretion was measured by ELISA. Gastrins activated PAK1 via PI3K-dependent pathways. Activated PAK1 in turn mediated gastrin-stimulated activation of β-catenin and VEGF secretion in CRC cells, as knockdown of PAK1 blocked stimulation of these cellular processes by gastrins. Downregulation of gastrin reduced the expression and activity of PAK1, but in contrast there was a compensatory increase in gastrins either when PAK1 was downregulated, or after treatment with a PAK inhibitor. Our results indicate that PAK1 is required for the stimulation of CRC cells by gastrins, and suggest the existence of an inhibitory feedback loop by which PAK1 downregulates gastrin production in CRC cells.
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Affiliation(s)
- Nhi Huynh
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Kevin H Liu
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Mildred Yim
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Arthur Shulkes
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Graham S Baldwin
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
| | - Hong He
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia
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20
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Yeo D, Huynh N, Beutler JA, Christophi C, Shulkes A, Baldwin GS, Nikfarjam M, He H. Glaucarubinone and gemcitabine synergistically reduce pancreatic cancer growth via down-regulation of P21-activated kinases. Cancer Lett 2014; 346:264-72. [PMID: 24491405 DOI: 10.1016/j.canlet.2014.01.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [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: 11/06/2013] [Revised: 12/22/2013] [Accepted: 01/03/2014] [Indexed: 12/24/2022]
Abstract
Pancreatic cancer is one of the most lethal of human malignancies. Nearly 100% cases of pancreatic cancer carry mutations in KRas. P-21-activated kinases (PAKs) are activated by and act downstream of KRas. Glaucarubinone, a natural product first isolated from the seeds of the tree Simarouba glauca, was originally developed as an antimalarial drug, and has more recently been recognised as an anticancer agent. The aims of this study were to determine whether glaucarubinone, alone or in combination with the front-line chemotherapeutic agent gemcitabine, would inhibit the growth of pancreatic cancer cells in vitro or in vivo and the mechanism involved. Growth of the human pancreatic cancer cell lines PANC-1 and MiaPaCa-2 was measured by (3)H-thymidine incorporation in vitro, and by volume as xenografts in SCID mice. The expression and activities of the two serine/threonine kinases PAK1 and PAK4, which are key regulators of cancer progression, were measured by Western blotting. Here we report that glaucarubinone decreased proliferation and migration of pancreatic cancer cells in vitro, and reduced their growth as xenografts in vivo. Treatment with glaucarubinone and gemcitabine reduced proliferation in vitro and tumor growth in vivo more than treatment with either glaucarubinone or gemcitabine alone. Treatment with glaucarubinone reduced PAK1 and PAK4 activities, which were further decreased by the combination of glaucarubinone and gemcitabine. These results indicate that glaucarubinone reduced pancreatic cancer cell growth at least in part via inhibition of pathways involving PAK1 and PAK4. The synergistic inhibition by glaucarubinone and gemcitabine observed both in vitro and in vivo suggests that glaucarubinone may be a useful adjunct to current regimes of chemotherapy.
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Affiliation(s)
- Dannel Yeo
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria 3084, Australia
| | - Nhi Huynh
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria 3084, Australia
| | - John A Beutler
- Molecular Targets Laboratory, National Cancer Institute, Frederick, MD 21702, United States
| | - Christopher Christophi
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria 3084, Australia
| | - Arthur Shulkes
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria 3084, Australia
| | - Graham S Baldwin
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria 3084, Australia
| | - Mehrdad Nikfarjam
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria 3084, Australia
| | - Hong He
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria 3084, Australia.
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21
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Bach N, Tuomilehto H, Gauthier C, Papadakis A, Remise C, Lavigne F, Lavigne GJ, Huynh N. The effect of surgically assisted rapid maxillary expansion on sleep architecture: an exploratory risk study in healthy young adults. J Oral Rehabil 2013; 40:818-25. [DOI: 10.1111/joor.12102] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2013] [Indexed: 11/27/2022]
Affiliation(s)
- N. Bach
- Faculty of Dental Medicine; Université de Montréal; Montreal QC Canada
| | - H. Tuomilehto
- Faculty of Dental Medicine; Université de Montréal; Montreal QC Canada
- Kuopio University Hospital; Kuopio Finland
| | - C. Gauthier
- Faculty of Dental Medicine; Université de Montréal; Montreal QC Canada
| | - A. Papadakis
- Faculty of Dental Medicine; Université de Montréal; Montreal QC Canada
| | - C. Remise
- Faculty of Dental Medicine; Université de Montréal; Montreal QC Canada
| | - F. Lavigne
- Faculty of Medicine; Université de Montréal; Montreal QC Canada
- Institut ORL de Montréal; Montreal QC Canada
| | - G. J. Lavigne
- Faculties of Dental Medicine and Medicine; Université de Montréal; Montreal QC Canada
- Sacré Coeur Hospital; Montreal QC Canada
| | - N. Huynh
- Faculty of Dental Medicine and CHU Sainte-Justine; Université de Montréal; Montreal QC Canada
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22
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Liu KH, Huynh N, Patel O, Shulkes A, Baldwin G, He H. P21-activated kinase 1 promotes colorectal cancer survival by up-regulation of hypoxia-inducible factor-1α. Cancer Lett 2013; 340:22-9. [PMID: 23811286 DOI: 10.1016/j.canlet.2013.06.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [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: 05/21/2013] [Revised: 06/18/2013] [Accepted: 06/20/2013] [Indexed: 12/16/2022]
Abstract
P21 activated kinase 1 (PAK1) enhances colorectal cancer (CRC) progression by stimulating Wnt/β-catenin and Ras oncogene, which promote CRC survival via stimulation of hypoxia-inducible factor 1α (HIF-1α). The aim of this study was to assess the mechanism involved in the stimulation by PAK1 of CRC survival. PAK1 promoted CRC cell survival by up-regulation of HIF-1α. PAK1 was over-expressed and hyper-activated in tumors of ApcΔ(14/+) mice, which was correlated with over-expression of HIF-1α and β-catenin. Inhibition of PAK1 decreased tumor growth and the expression of HIF-1α and β-catenin in tumors of ApcΔ(14/+) mice, and suppressed xenograft tumor survival in SCID mice. These findings indicate that PAK1 stimulates CRC survival by up-regulation of HIF-1α.
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Affiliation(s)
- Kevin H Liu
- Department of Surgery, University of Melbourne, Austin Health, Heidelberg, Victoria 3084, Australia
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23
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Huynh N, Yim M, Chernoff J, Shulkes A, Baldwin GS, He H. p-21-Activated kinase 1 mediates gastrin-stimulated proliferation in the colorectal mucosa via multiple signaling pathways. Am J Physiol Gastrointest Liver Physiol 2013; 304:G561-7. [PMID: 23306081 PMCID: PMC3602683 DOI: 10.1152/ajpgi.00218.2012] [Citation(s) in RCA: 8] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gastrins, including amidated (Gamide) and glycine-extended (Ggly) forms, function as growth factors for the gastrointestinal mucosa. The p-21-activated kinase 1 (PAK1) plays important roles in growth factor signaling networks that control cell motility, proliferation, differentiation, and transformation. PAK1, activated by both Gamide and Ggly, mediates gastrin-stimulated proliferation and migration, and activation of β-catenin, in gastric epithelial cells. The aim of this study was to investigate the role of PAK1 in the regulation by gastrin of proliferation in the normal colorectal mucosa in vivo. Mucosal proliferation was measured in PAK1 knockout (PAK1 KO) mice by immunohistochemistry. The expression of phosphorylated and unphosphorylated forms of the signaling molecules PAK1, extracellular signal-regulated kinase (ERK), and protein kinase B (AKT), and the expression of β-catenin and its downstream targets c-Myc and cyclin D1, were measured in gastrin knockout (Gas KO) and PAK1 KO mice by Western blotting. The expression and activation of PAK1 are decreased in Gas KO mice, and these decreases are associated with reduced activation of ERK, AKT, and β-catenin. Proliferation in the colorectal mucosa of PAK1 KO mice is reduced, and the reduction is associated with reduced activation of ERK, AKT, and β-catenin. In compensation, antral gastrin mRNA and serum gastrin concentrations are increased in PAK1 KO mice. These results indicate that PAK1 mediates the stimulation of colorectal proliferation by gastrins via multiple signaling pathways involving activation of ERK, AKT, and β-catenin.
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Affiliation(s)
- Nhi Huynh
- 1Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia; and
| | - Mildred Yim
- 1Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia; and
| | | | - Arthur Shulkes
- 1Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia; and
| | - Graham S. Baldwin
- 1Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia; and
| | - Hong He
- 1Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria, Australia; and
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Broukhim M, Reeves A, Huynh N, Liu M. P04.31. Determining attitudes and use of complementary and alternative medicine and integrative medicine amongst undergraduates. Altern Ther Health Med 2012. [PMCID: PMC3373680 DOI: 10.1186/1472-6882-12-s1-p301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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25
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Huynh N, Sarma D, Huerter C. Erythema ab igne: a case report and review of the literature. Cutis 2011; 88:290-292. [PMID: 22372168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Erythema ab igne (EAI) is a rare condition since the advent of central heating. Its incidence has been rising as heating sources are being used to treat chronic pain. Multiple activities that chronically expose patients to heating sources also have been documented with this condition. We present a case of EAI induced by the use of an electric blanket.
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Affiliation(s)
- Nhi Huynh
- Creighton University Medical Center, Omaha, Nebraska 68131, USA
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26
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Neco P, Rose B, Huynh N, Zhang R, Bridge JHB, Philipson KD, Goldhaber JI. Sodium-calcium exchange is essential for effective triggering of calcium release in mouse heart. Biophys J 2010; 99:755-64. [PMID: 20682252 DOI: 10.1016/j.bpj.2010.04.071] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 03/26/2010] [Accepted: 04/30/2010] [Indexed: 11/30/2022] Open
Abstract
In cardiac myocytes, excitation-contraction coupling depends upon sarcoplasmic reticular Ca2+ release triggered by Ca2+ influx through L-type Ca2+ channels. Although Na+-Ca2+ exchange (NCX) is essential for Ca2+ extrusion, its participation in the trigger process of excitation-contraction coupling is controversial. To investigate the role of NCX in triggering, we examined Ca2+ sparks in ventricular cardiomyocytes isolated from wild-type (WT) and cardiac-specific NCX knockout (KO) mice. Myocytes from young NCX KO mice are known to exhibit normal resting cytosolic Ca2+ and normal Ca2+ transients despite reduced L-type Ca2+ current. We loaded myocytes with fluo-3 to image Ca2+ sparks using confocal microscopy in line-scan mode. The frequency of spontaneous Ca2+ sparks was reduced in KO myocytes compared with WT. However, spark amplitude and width were increased in KO mice. Permeabilizing the myocytes with saponin eliminated differences between spontaneous sparks in WT and KO mice. These results suggest that sarcolemmal processes are responsible for the reduced spark frequency and increased spark width and amplitude in KO mice. When myocytes were loaded with 1 mM fluo-3 and 3 mM EGTA via the patch pipette to buffer diadic cleft Ca2+, the number of sparks triggered by action potentials was reduced by 60% in KO cells compared to WT cells, despite similar SR Ca2+ content in both cell types. When EGTA was omitted from the pipette solution, the number of sparks triggered in KO and WT myocytes was similar. Although the number of sparks was restored in KO cells, Ca2+ release was asynchronous. These results suggest that high subsarcolemmal Ca2+ is required to ensure synchronous triggering with short spark latency in the absence of NCX. In WT mice, high subsarcolemmal Ca2+ is not required for synchronous triggering, because NCX is capable of priming the diadic cleft with sufficient Ca2+ for normal triggering, even when subsarcolemmal Ca(2+) is lowered by EGTA. Thus, reducing subsarcolemmal Ca2+ with EGTA in NCX KO mice reveals the dependence of Ca2+ release on NCX.
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Affiliation(s)
- Patricia Neco
- Departments of Medicine (Cardiology) and Physiology and the Cardiovascular Research Laboratories, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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Huynh N, Liu KH, Baldwin GS, He H. P21-activated kinase 1 stimulates colon cancer cell growth and migration/invasion via ERK- and AKT-dependent pathways. Biochim Biophys Acta 2010; 1803:1106-13. [PMID: 20595063 DOI: 10.1016/j.bbamcr.2010.05.007] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 05/20/2010] [Accepted: 05/24/2010] [Indexed: 12/22/2022]
Abstract
The p21-activated kinase (PAK) family of serine/threonine kinases plays an important role in cell proliferation, survival and motility, as well as in cell transformation and tumor progression. PAK1 promotes transformation through facilitating the ERK/MAPK pathway and enhances cell migration and survival by stimulating AKT. PAK1 expression increases with the progression of colorectal cancer (CRC). In this study, we have investigated the importance of PAK1 in the biology of colon cancer cells. Reduction of PAK1 expression decreased the activities of ERK and AKT leading to decreased cell proliferation, migration/invasion, and survival. Dual inhibition of ERK and AKT suppressed these cellular processes to levels comparable to those achieved by reduction of PAK1 expression, whereas inactivation of either the ERK or AKT pathway alone partially inhibited cell migration/invasion and survival and had no effect on proliferation. We conclude that PAK1 stimulates colon cancer cell proliferation, migration/invasion, and survival via ERK- and AKT-dependent pathways. These findings establish the central importance of PAK1 in CRC signal transduction and clarify the mechanism by which PAK1 regulates CRC growth and migration. Instead of simultaneously inhibiting both ERK and AKT, the PAK1 convergence point could be an alternative target for CRC therapy.
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Affiliation(s)
- Nhi Huynh
- Department of Surgery, University of Melbourne, Austin Health, Melbourne, Victoria 3084, Australia
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Klosowska K, Volin MV, Huynh N, Chong KK, Halloran MM, Woods JM. Fractalkine functions as a chemoattractant for osteoarthritis synovial fibroblasts and stimulates phosphorylation of mitogen-activated protein kinases and Akt. Clin Exp Immunol 2009; 156:312-9. [PMID: 19302240 DOI: 10.1111/j.1365-2249.2009.03903.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Fractalkine (FKN/CX3CL1) has been detected in synovial fluids from osteoarthritis (OA) patients. Additionally, low-level expression of the FKN receptor, CX3CR1, has been demonstrated in OA synovial lining. This study aimed to determine a biological function for this ligand/receptor pair in OA and to assess a potential signalling mechanism for FKN in this predominant synovial lining cell type, using chemotaxis assays, Western blotting and F-actin staining. Chemotaxis assays demonstrate that the chemokine domain of FKN effectively induces migration of OA fibroblasts. Consistent with this finding, visualization of F-actin demonstrates that 1 or 10 nM FKN induces noticeable reorganization of cytoskeletal structure in OA fibroblasts after 30 min stimulation with a maximal enhancement at approximately 2 h. In addition, Western blotting analysis demonstrates that FKN stimulates phosphorylation of the mitogen-activated protein (MAP) kinases p38, c-Jun N-terminal kinase (JNK) and extracellular-regulated kinase (ERK) 1/2 as well as the serine-threonine kinase Akt at Ser 473 and Thr 308. All these phosphorylation events occur in a time-dependent manner, with little or no activation within 1 min, and maximal activation occurring typically between 5 and 30 min. Moreover, inhibition of ERK 1/2 significantly reduces FKN-induced OA fibroblast migration. These results suggest that FKN is a novel chemoattractant for OA fibroblasts, consistent with FKN-induced alterations in cytoskeletal structure. In addition, FKN induces OA fibroblast signalling via the MAP kinases p38, JNK and ERK 1/2, as well as Akt.
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Affiliation(s)
- K Klosowska
- Department of Microbiology and Immunology, Chicago College of Osteopathic Medicine, Chicago, IL 60515, USA
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Huynh N, Duh Q, Clark O, Kebebew E. QS136. KIAA0101 is Overexpressed in Adrenocortical Carcinoma and Regulates Cell Growth. J Surg Res 2009. [DOI: 10.1016/j.jss.2008.11.433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
Fibroepithelioma of Pinkus (FEP) is a rare indolent variety of basal cell carcinoma that is typically polypoid and located on the trunk of adult males aged 40–60 years. Basal cell carcinoma (including FEP) is very rare in the pediatric population. We are reporting such a case occurring in a 9-year-old boy.
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Affiliation(s)
- Zenggang Pan
- Department of Pathology, Creighton University Medical Center, Omaha, NE 68131, USA.
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Huynh N, Kato T, Rompré PH, Okura K, Saber M, Lanfranchi PA, Montplaisir JY, Lavigne GJ. Sleep bruxism is associated to micro-arousals and an increase in cardiac sympathetic activity. J Sleep Res 2006; 15:339-46. [PMID: 16911037 DOI: 10.1111/j.1365-2869.2006.00536.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Sleep bruxism (SB) subjects show a higher incidence of rhythmic masticatory muscle activity (RMMA) than control subjects. RMMA is associated with sleep micro-arousals. This study aims to: (i) assess RMMA/SB episodes in relation to sleep cycles; (ii) establish if RMMA/SB and micro-arousals occur in relation to the slow wave activity (SWA) dynamics; (iii) analyze the association between RMMA/SB and autonomic cardiac activity across sleep cycles. Two nights of polygraphic recordings were made in three study groups (20 subjects each): moderate to high SB, low SB and control. RMMA episodes were considered to occur in clusters when several groups of RMMA or non-specific oromotor episodes were separated by less than 100 s. Correlations between sleep, RMMA/SB index and heart rate variability variables were assessed for the first four sleep cycles of each study group. Statistical analyses were done with SYSTAT and SPSS. It was observed that 75.8% of all RMMA/SB episodes occurred in clusters. Micro-arousal and SB indexes were highest during sleep cycles 2 and 3 (P < 0.001). Within each cycle, micro-arousal and RMMA/SB indexes showed an increase before each REM sleep (P <or= 0.02). The cross-correlation plot for micro-arousal index showed positive association from 4 min preceding SB onset in the moderate to high SB subjects (P <or= 0.06). The cross-correlation plot revealed that SWA decreases following SB onset (P <or= 0.05). Further cross-correlation analysis revealed that a shift in sympatho-vagal balance towards increased sympathetic activity started 8 min preceding SB onset (P <or= 0.03). In moderate to severe SB subjects, a clear increase in sympathetic activity precedes SB onset.
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Affiliation(s)
- N Huynh
- Facultés de médecine dentaire et de médecine, Université de Montréal, Montréal, QC, Canada
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Gray JD, Liu T, Huynh N, Horwitz DA. Transforming growth factor beta enhances the expression of CD154 (CD40L) and production of tumor necrosis factor alpha by human T lymphocytes. Immunol Lett 2001; 78:83-8. [PMID: 11672591 DOI: 10.1016/s0165-2478(01)00233-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Activation of lymphocytes in the presence of transforming growth factor beta (TGFbeta) can impair or enhance their functional activity. We have found that TGFbeta is important in the generation of lymphocytes, which are capable of suppressing antibody production. To better understand how this cytokine affects lymphocyte activity, we looked at the expression of early activation events of T cells stimulated in the presence or absence of TGFbeta. The results show that TGFbeta enhances the expression of CD154 (CD40L), TNFR2 and the production of TNFalpha. These findings clarify the co-stimulatory effects of TGFbeta that enhance T lymphocyte activation.
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Affiliation(s)
- J D Gray
- Division of Rheumatology and Immunology, Keck School of Medicine, University of Southern California, HMR 711, 2011 Zonal Avenue, Los Angeles, CA 90033, USA.
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Rich T, Chen P, Furman F, Huynh N, Israel MA. RTVP-1, a novel human gene with sequence similarity to genes of diverse species, is expressed in tumor cell lines of glial but not neuronal origin. Gene 1996; 180:125-30. [PMID: 8973356 DOI: 10.1016/s0378-1119(96)00431-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A novel gene, RTVP-1, which shows significant sequence identity to the mammalian testis-specific proteins, a family of plant pathogenesis-related proteins and the vespid venom allergen, antigen-5, has been isolated from a cDNA library of the human glioblastoma brain tumor cell line, U-251 MG. The highest degree of sequence identity was with the human testis-specific protein, TPX1 (38.7% over 119 amino acids). Northern hybridization analysis revealed that in fetal tissue RTVP-1 RNA was detected only in the kidney, but its expression was ubiquitous in adult tissues including brain. Multiple mRNAs encoded by RTVP-1 were highly expressed in a panel of cell lines from nervous system tumors arising from glia, although expression was low or absent in nonglial-derived nervous system tumor cell lines.
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Affiliation(s)
- T Rich
- Preuss Laboratory for Molecular Neuro-oncology, Department of Neurological Surgery, School of Medicine, University of California San Francisco 94143-0520, USA
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Garguilo MG, Huynh N, Proctor A, Michael AC. Amperometric sensors for peroxide, choline, and acetylcholine based on electron transfer between horseradish peroxidase and a redox polymer. Anal Chem 1993; 65:523-8. [PMID: 8452244 DOI: 10.1021/ac00053a007] [Citation(s) in RCA: 162] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Amperometric sensors have been developed for hydrogen peroxide, choline, and acetylcholine by immobilization of horseradish peroxidase, (HRP), choline oxidase, and acetylcholinesterase in a cross-linked redox polymer deposited on glassy carbon electrodes. Peroxide sensors, prepared by immobilization of HRP alone, gave detection limits of 10 nM and a linear response up to ca. 1 mM. Coimmobilization of HRP and glucose oxidase was used to establish the feasibility of highly efficient bienzyme sensors at low substrate levels. Replacing glucose oxidase with choline oxidase produced sensors with submicromolar detection limits and a linear response up to 0.8 mM. Addition of acetylcholinesterase to the sensors generated a relatively small response to acetylcholine that demonstrates the feasibility of trienzyme sensors. At low substrate concentrations, no loss in sensitivity during a 1-day experiment was observed. The response times of these sensors are all less than 30 s with 2-s response times achieved in some cases.
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Affiliation(s)
- M G Garguilo
- Department of Chemistry, University of Pittsburgh, Pennsylvania 15260
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