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Jayaprasad AG, Chandrasekharan A, Arun Jyothi SP, John Sam SM, Santhoshkumar TR, Pillai MR. Telomerase inhibitors induce mitochondrial oxidation and DNA damage-dependent cell death rescued by Bcl-2/Bcl-xL. Int J Biol Macromol 2024; 264:130151. [PMID: 38403227 DOI: 10.1016/j.ijbiomac.2024.130151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/05/2024] [Accepted: 02/11/2024] [Indexed: 02/27/2024]
Abstract
BACKGROUND Reactivation of telomerase is a hallmark of cancer and the majority of cancers over-express telomerase. Telomerase-dependent telomere length maintenance confers immortality to cancer cells. However, telomere length-independent cell survival functions of telomerase also play a critical role in tumorigenesis. Multiple telomerase inhibitors have been developed as therapeutics and include anti-sense oligonucleotides, telomerase RNA component targeting agents, chemical inhibitors of telomerase, small molecule inhibitors of hTERT, and telomerase vaccine. In general, telomerase inhibitors affect cell proliferation and survival of cells depending on the telomere length reduction, culminating in replicative senescence or cell death by crisis. However, most telomerase inhibitors kill cancer cells prior to significant reduction in telomere length, suggesting telomere length independent role of telomerase in early telomere dysfunction-dependent cell death. METHODS In this study, we explored the mechanism of cell death induced by three prominent telomerase inhibitors utilizing a series of genetically encoded sensor cells including redox and DNA damage sensor cells. RESULTS We report that telomerase inhibitors induce early cell cycle inhibition, followed by redox alterations at cytosol and mitochondria. Massive mitochondrial oxidation and DNA damage induce classical cell death involving mitochondrial transmembrane potential loss and mitochondrial permeabilization. Real-time imaging of the progression of mitochondrial oxidation revealed that treated cells undergo a biphasic mitochondrial redox alteration during telomerase inhibition, emphasizing the potential role of telomerase in the redox regulation at mitochondria. Additionally, silencing of hTERT confirmed its predominant role in maintaining mitochondrial redox homeostasis. Interestingly, the study also demonstrated that anti-apoptotic Bcl-2 family proteins still confer protection against cell death induced by telomerase inhibitors. CONCLUSION The study demonstrates that redox alterations and DNA damage contribute to early cell death by telomerase inhibitors and anti-apoptotic Bcl-2 family proteins confer protection from cell death by their ability to safeguard mitochondria from oxidation damage.
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Affiliation(s)
- Aparna Geetha Jayaprasad
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India; PhD Program, Manipal Academy of Higher Education (MAHE), Madhav Nagar, Manipal, Karnataka 576104, India
| | - Aneesh Chandrasekharan
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India
| | - S P Arun Jyothi
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India
| | - S M John Sam
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India
| | - T R Santhoshkumar
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India.
| | - M Radhakrishna Pillai
- Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Poojappura, Thycaud, Thiruvananthapuram 695014, Kerala, India.
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2
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Kok CY, MacLean LM, Rao R, Tsurusaki S, Kizana E. Promoter Optimization Circumvents Bcl-2 Transgene-Mediated Suppression of Lentiviral Vector Production. Biomolecules 2023; 13:1397. [PMID: 37759797 PMCID: PMC10526134 DOI: 10.3390/biom13091397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/13/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
Lentiviral vectors are a robust gene delivery tool for inducing transgene expression in a variety of cells. They are well suited to facilitate the testing of therapeutic candidate genes in vitro, due to relative ease of packaging and ability to transduce dividing and non-dividing cells. Our goal was to identify a gene that could be delivered to the heart to protect against cancer-therapy-induced cardiotoxicity. We sought to generate a lentivirus construct with a ubiquitous CMV promoter driving expression of B-cell lymphocyte/leukemia 2 gene (Bcl-2), a potent anti-apoptotic gene. Contrary to our aim, overexpression of Bcl-2 induced cell death in the producer HEK293T cells, resulting in failure to produce usable vector titre. This was circumvented by exchanging the CMV promoter to the cardiac-specific NCX1 promoter, leading to the successful production of a lentiviral vector which could induce cardioprotective expression of Bcl-2. In conclusion, reduced expression of Bcl-2 driven by a weaker promoter improved vector yield, and led to the production of functional cardioprotective Bcl-2 in primary cardiomyocytes.
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Affiliation(s)
- Cindy Y. Kok
- Centre for Heart Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (C.Y.K.); (L.M.M.); (R.R.); (S.T.)
- Westmead Clinical School, The University of Sydney, Westmead, NSW 2145, Australia
| | - Lauren M. MacLean
- Centre for Heart Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (C.Y.K.); (L.M.M.); (R.R.); (S.T.)
| | - Renuka Rao
- Centre for Heart Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (C.Y.K.); (L.M.M.); (R.R.); (S.T.)
| | - Shinya Tsurusaki
- Centre for Heart Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (C.Y.K.); (L.M.M.); (R.R.); (S.T.)
- Westmead Clinical School, The University of Sydney, Westmead, NSW 2145, Australia
| | - Eddy Kizana
- Centre for Heart Research, The Westmead Institute for Medical Research, Westmead, NSW 2145, Australia; (C.Y.K.); (L.M.M.); (R.R.); (S.T.)
- Westmead Clinical School, The University of Sydney, Westmead, NSW 2145, Australia
- Department of Cardiology, Westmead Hospital, Westmead, NSW 2145, Australia
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3
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Bandla AC, Sheth AS, Zarate SM, Uskamalla S, Hager EC, Villarreal VA, González-García M, Ballestero RP. Enhancing structural plasticity of PC12 neurons during differentiation and neurite regeneration with a catalytically inactive mutant version of the zRICH protein. BMC Neurosci 2023; 24:43. [PMID: 37612637 PMCID: PMC10463786 DOI: 10.1186/s12868-023-00808-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 06/23/2023] [Indexed: 08/25/2023] Open
Abstract
BACKGROUND Studies of the molecular mechanisms of nerve regeneration have led to the discovery of several proteins that are induced during successful nerve regeneration. RICH proteins were identified as proteins induced during the regeneration of the optic nerve of teleost fish. These proteins are 2',3'-cyclic nucleotide, 3'-phosphodiesterases that can bind to cellular membranes through a carboxy-terminal membrane localization domain. They interact with the tubulin cytoskeleton and are able to enhance neuronal structural plasticity by promoting the formation of neurite branches. RESULTS PC12 stable transfectant cells expressing a fusion protein combining a red fluorescent protein with a catalytically inactive mutant version of zebrafish RICH protein were generated. These cells were used as a model to analyze effects of the protein on neuritogenesis. Differentiation experiments showed a 2.9 fold increase in formation of secondary neurites and a 2.4 fold increase in branching points. A 2.2 fold increase in formation of secondary neurites was observed in neurite regeneration assays. CONCLUSIONS The use of a fluorescent fusion protein facilitated detection of expression levels. Two computer-assisted morphometric analysis methods indicated that the catalytically inactive RICH protein induced the formation of branching points and secondary neurites both during differentiation and neurite regeneration. A procedure based on analysis of random field images provided comparable results to classic neurite tracing methods.
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Affiliation(s)
- Ashoka C Bandla
- Department of Biological and Health Sciences, Texas A&M University-Kingsville, 700 University Blvd, Kingsville, TX, 78363, USA
| | - Aditya S Sheth
- Department of Biological and Health Sciences, Texas A&M University-Kingsville, 700 University Blvd, Kingsville, TX, 78363, USA
| | - Sara M Zarate
- Department of Biological and Health Sciences, Texas A&M University-Kingsville, 700 University Blvd, Kingsville, TX, 78363, USA
| | - Suraj Uskamalla
- Department of Biological and Health Sciences, Texas A&M University-Kingsville, 700 University Blvd, Kingsville, TX, 78363, USA
| | - Elizabeth C Hager
- Department of Biological and Health Sciences, Texas A&M University-Kingsville, 700 University Blvd, Kingsville, TX, 78363, USA
| | - Victor A Villarreal
- Department of Chemistry, Texas A&M University-Kingsville, Kingsville, TX, 78363, USA
| | | | - Rafael P Ballestero
- Department of Biological and Health Sciences, Texas A&M University-Kingsville, 700 University Blvd, Kingsville, TX, 78363, USA.
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4
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Fan X, Zhao B, Zhang W, Li N, Mi K, Wang B. Coevolution of furA-Regulated Hyper-Inflammation and Mycobacterial Resistance to Oxidative Killing through Adaptation to Hydrogen Peroxide. Microbiol Spectr 2023; 11:e0536722. [PMID: 37358434 PMCID: PMC10433983 DOI: 10.1128/spectrum.05367-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 05/25/2023] [Indexed: 06/27/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is highly resistant to host oxidative killing. We hypothesized that the evolutionary adaptation of M. smegmatis to hydrogen peroxide (H2O2) would endow the nonpathogenic Mycobacterium persistent in a host. In the study, we screened a highly H2O2-resistant strain (mc2114) via evolutionary H2O2 adaptation in vitro. The MIC of mc2114 to H2O2 is 320 times that of wild-type mc2155. Mouse infection experiments showed that mc2114, similar to Mtb, was persistent in the lungs and caused high lethality in mice with restricted responses of NOX2, ROS, IFN-γ, decreased macrophage apoptosis, and overexpressed inflammatory cytokines in the lungs. Whole-genome sequencing analysis revealed that mc2114 harbored 29 single nucleotide polymorphisms in multiple genes; one of them was on the furA gene that caused FurA deficiency-mediated overexpression of KatG, a catalase-peroxidase to detoxify ROS. Complementation of mc2114 with a wild-type furA gene reversed lethality and hyper-inflammatory response in mice with rescued overexpression of KatG and inflammatory cytokines, whereas NOX2, ROS, IFN-γ, and macrophage apoptosis remained reduced. The results indicate that although FurA regulates KatG expression, it does not contribute significantly to the restriction of ROS response. Instead, FurA deficiency is responsible for the detrimental pulmonary inflammation that contributes to the severity of the infection, a previously nonrecognized function of FurA in mycobacterial pathogenesis. The study also indicates that mycobacterial resistance to oxidative burst results from complex mechanisms involving adaptive genetic changes in multiple genes. IMPORTANCE Mycobacterium tuberculosis (Mtb) causes human tuberculosis (TB), which has killed more people in human history than any other microorganism. However, the mechanisms underlying Mtb pathogenesis and related genes have not yet been fully elucidated, which impedes the development of effective strategies for containing and eradicating TB. In the study, we generated a mutant of M. smegmatis (mc2114) with multiple mutations by an adaptive evolutionary screen with H2O2. One of the mutations in furA caused a deficiency of FurA, which mediated severe inflammatory lung injury and higher lethality in mice by overexpression of inflammatory cytokines. Our results indicate that FurA-regulated pulmonary inflammation plays a critical role in mycobacterial pathogenesis in addition to the known downregulation of NOX2, ROS, IFN-γ responses, and macrophage apoptosis. Further analysis of the mutations in mc2114 would identify more genes related to the increased pathogenicity and help in devising new strategies for containing and eradicating TB.
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Affiliation(s)
- Xin Fan
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Bei Zhao
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Weishan Zhang
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Ning Li
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Kaixia Mi
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
| | - Beinan Wang
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China
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5
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Paradise BD, Gainullin VG, Almada LL, Sigafoos AN, Sen S, Vera RE, Raja Arul GL, Toruner M, Pease DR, Gonzalez AL, Mentucci FM, Grasso DH, Fernandez-Zapico ME. SUFU promotes GLI activity in a Hedgehog-independent manner in pancreatic cancer. Biochem J 2023; 480:1199-1216. [PMID: 37477952 DOI: 10.1042/bcj20220439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/22/2023]
Abstract
Aberrant activation of the Hedgehog (Hh) signaling pathway, through which the GLI family of transcription factors (TF) is stimulated, is commonly observed in cancer cells. One well-established mechanism of this increased activity is through the inactivation of Suppressor of Fused (SUFU), a negative regulator of the Hh pathway. Relief from negative regulation by SUFU facilitates GLI activity and induction of target gene expression. Here, we demonstrate a novel role for SUFU as a promoter of GLI activity in pancreatic ductal adenocarcinoma (PDAC). In non-ciliated PDAC cells unresponsive to Smoothened agonism, SUFU overexpression increases GLI transcriptional activity. Conversely, knockdown (KD) of SUFU reduces the activity of GLI in PDAC cells. Through array PCR analysis of GLI target genes, we identified B-cell lymphoma 2 (BCL2) among the top candidates down-regulated by SUFU KD. We demonstrate that SUFU KD results in reduced PDAC cell viability, and overexpression of BCL2 partially rescues the effect of reduced cell viability by SUFU KD. Further analysis using as a model GLI1, a major TF activator of the GLI family in PDAC cells, shows the interaction of SUFU and GLI1 in the nucleus through previously characterized domains. Chromatin immunoprecipitation (ChIP) assay shows the binding of both SUFU and GLI1 at the promoter of BCL2 in PDAC cells. Finally, we demonstrate that SUFU promotes GLI1 activity without affecting its protein stability. Through our findings, we propose a novel role of SUFU as a positive regulator of GLI1 in PDAC, adding a new mechanism of Hh/GLI signaling pathway regulation in cancer cells.
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Affiliation(s)
- Brooke D Paradise
- Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN 55905, U.S.A
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN 55905, U.S.A
| | | | - Luciana L Almada
- Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN 55905, U.S.A
| | - Ashley N Sigafoos
- Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN 55905, U.S.A
| | - Sandhya Sen
- Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN 55905, U.S.A
| | - Renzo E Vera
- Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN 55905, U.S.A
| | - Glancis Luzeena Raja Arul
- Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN 55905, U.S.A
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN 55905, U.S.A
| | - Murat Toruner
- Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN 55905, U.S.A
| | - David R Pease
- Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN 55905, U.S.A
- Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN 55905, U.S.A
| | - Alina L Gonzalez
- Facultad de Ciencias Exactas y Naturales, Instituto de Ciencias de la Tierra y Ambientales de La Pampa (INCITAP), Universidad Nacional de La Pampa - Consejo Nacional de Investigaciones Científicas y Técnicas (UNLPam-CONICET), La Pampa 6300, Argentina
| | | | - Daniel H Grasso
- Instituto de Estudios de la Inmunidad Humoral (IDEHU), Escuela de Farmacia y Bioquimica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires 1113, Argentina
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6
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Kumari A, Gesumaria L, Liu YJ, Hughitt VK, Zhang X, Ceribelli M, Wilson KM, Klumpp-Thomas C, Chen L, McKnight C, Itkin Z, Thomas CJ, Mock BA, Schrump DS, Chen H. mTOR inhibition overcomes RSK3-mediated resistance to BET inhibitors in small cell lung cancer. JCI Insight 2023; 8:156657. [PMID: 36883564 PMCID: PMC10077471 DOI: 10.1172/jci.insight.156657] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/23/2023] [Indexed: 03/09/2023] Open
Abstract
Small cell lung cancer (SCLC) is a recalcitrant malignancy with limited treatment options. Bromodomain and extraterminal domain inhibitors (BETis) have shown promising preclinical activity in SCLC, but the broad sensitivity spectrum limits their clinical prospects. Here, we performed unbiased high-throughput drug combination screens to identify therapeutics that could augment the antitumor activities of BETis in SCLC. We found that multiple drugs targeting the PI-3K-AKT-mTOR pathway synergize with BETis, among which mTOR inhibitors (mTORis) show the highest synergy. Using various molecular subtypes of the xenograft models derived from patients with SCLC, we confirmed that mTOR inhibition potentiates the antitumor activities of BETis in vivo without substantially increasing toxicity. Furthermore, BETis induce apoptosis in both in vitro and in vivo SCLC models, and this antitumor effect is further amplified by combining mTOR inhibition. Mechanistically, BETis induce apoptosis in SCLC by activating the intrinsic apoptotic pathway. However, BET inhibition leads to RSK3 upregulation, which promotes survival by activating the TSC2-mTOR-p70S6K1-BAD cascade. mTORis block this protective signaling and augment the apoptosis induced by BET inhibition. Our findings reveal a critical role of RSK3 induction in tumor survival upon BET inhibition and warrant further evaluation of the combination of mTORis and BETis in patients with SCLC.
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Affiliation(s)
| | | | | | - V Keith Hughitt
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Xiaohu Zhang
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland, USA
| | - Michele Ceribelli
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland, USA
| | - Kelli M Wilson
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland, USA
| | - Carleen Klumpp-Thomas
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland, USA
| | - Lu Chen
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland, USA
| | - Crystal McKnight
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland, USA
| | - Zina Itkin
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland, USA
| | - Craig J Thomas
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, Maryland, USA.,Lymphoid Malignancies Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
| | - Beverly A Mock
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland, USA
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7
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Chen H, Gesumaria L, Park YK, Oliver TG, Singer DS, Ge K, Schrump DS. BET Inhibitors Target the SCLC-N Subtype of Small-Cell Lung Cancer by Blocking NEUROD1 Transactivation. Mol Cancer Res 2023; 21:91-101. [PMID: 36378541 PMCID: PMC9898120 DOI: 10.1158/1541-7786.mcr-22-0594] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/27/2022] [Accepted: 11/04/2022] [Indexed: 11/16/2022]
Abstract
Small-cell lung cancer (SCLC) is a recalcitrant malignancy that urgently needs new therapies. Four master transcription factors (ASCL1, NEUROD1, POU2F3, and YAP1) have been identified in SCLC, and each defines the transcriptome landscape of one molecular subtype. However, these master transcription factors have not been found directly druggable. We hypothesized that blocking their transcriptional coactivator(s) could provide an alternative approach to target these master transcription factors. Here, we identify that BET proteins physically interact with NEUROD1 and function as transcriptional coactivators. Using CRISPR knockout and ChIP-seq, we demonstrate that NEUROD1 plays a critical role in defining the landscapes of BET proteins in the SCLC genome. Blocking BET proteins by inhibitors led to broad suppression of the NEUROD1-target genes, especially those associated with superenhancers, resulting in the inhibition of SCLC growth in vitro and in vivo. LSAMP, a membrane protein in the IgLON family, was identified as one of the NEUROD1-target genes mediating BET inhibitor sensitivity in SCLC. Altogether, our study reveals that BET proteins are essential in regulating NEUROD1 transactivation and are promising targets in SCLC-N subtype tumors. IMPLICATIONS Our findings suggest that targeting transcriptional coactivators could be a novel approach to blocking the master transcription factors in SCLC for therapeutic purposes.
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Affiliation(s)
- Haobin Chen
- Thoracic Surgery Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Corresponding author: Address: 660 S. Euclid Avenue, Campus Box 8069, St. Louis, MO 63110, Tel: 314-273-5244;
| | - Lisa Gesumaria
- Thoracic Surgery Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Young-Kwon Park
- Adipocyte Biology and Gene Regulation Section, Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Trudy G. Oliver
- Department of Pharmacology & Cancer Biology, School of Medicine, Duke University, Durham, NC 27708, USA
| | - Dinah S. Singer
- Experimental Immunology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kai Ge
- Adipocyte Biology and Gene Regulation Section, Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - David S. Schrump
- Thoracic Surgery Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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8
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iRhom pseudoproteases regulate ER stress-induced cell death through IP 3 receptors and BCL-2. Nat Commun 2022; 13:1257. [PMID: 35273168 PMCID: PMC8913617 DOI: 10.1038/s41467-022-28930-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/17/2022] [Indexed: 12/13/2022] Open
Abstract
The folding capacity of membrane and secretory proteins in the endoplasmic reticulum (ER) can be challenged by physiological and pathological perturbations, causing ER stress. If unresolved, this leads to cell death. We report a role for iRhom pseudoproteases in controlling apoptosis due to persistent ER stress. Loss of iRhoms causes cells to be resistant to ER stress-induced apoptosis. iRhom1 and iRhom2 interact with IP3 receptors, critical mediators of intracellular Ca2+ signalling, and regulate ER stress-induced transport of Ca2+ into mitochondria, a primary trigger of mitochondrial membrane depolarisation and cell death. iRhoms also bind to the anti-apoptotic regulator BCL-2, attenuating the inhibitory interaction between BCL-2 and IP3 receptors, which promotes ER Ca2+ release. The discovery of the participation of iRhoms in the control of ER stress-induced cell death further extends their potential pathological significance to include diseases dependent on protein misfolding and aggregation. Cells that cannot cope with persistent endoplasmic reticulum stress will die. Here, the authors show that iRhom pseudoproteases regulate cell death by modulating the ability of BCL-2 to inhibit calcium flow through IP3R channels.
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9
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Tian T, Cao X, Kim SE, Lin YL, Steele JW, Cabrera RM, Karki M, Yang W, Marini NJ, Hoffman EN, Han X, Hu C, Wang L, Wlodarczyk BJ, Shaw GM, Ren A, Finnell RH, Lei Y. FKBP8 variants are risk factors for spina bifida. Hum Mol Genet 2021; 29:3132-3144. [PMID: 32969478 DOI: 10.1093/hmg/ddaa211] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 09/13/2020] [Accepted: 09/17/2020] [Indexed: 12/17/2022] Open
Abstract
Neural tube defects (NTDs) are a group of severe congenital malformations caused by a failure of neural tube closure during early embryonic development. Although extensively investigated, the genetic etiology of NTDs remains poorly understood. FKBP8 is critical for proper mammalian neural tube closure. Fkbp8-/- mouse embryos showed posterior NTDs consistent with a diagnosis of spina bifida (SB). To date, no publication has reported any association between FKBP8 and human NTDs. Using Sanger sequencing on genomic DNA samples from 472 SB and 565 control samples, we identified five rare (MAF ≤ 0.001) deleterious variants in SB patients, while no rare deleterious variant was identified in the controls (P = 0.0191). p.Glu140* affected FKBP8 localization to the mitochondria and created a truncated form of the FKBP8 protein, thus impairing its interaction with BCL2 and ultimately leading to an increase in cellular apoptosis. p.Ser3Leu, p.Lys315Asn and p.Ala292Ser variants decreased FKBP8 protein level. p.Lys315Asn further increased the cellular apoptosis. RNA sequencing on anterior and posterior tissues isolated from Fkbp8-/- and wildtype mice at E9.5 and E10.5 showed that Fkbp8-/- embryos have an abnormal expression profile within tissues harvested at posterior sites, thus leading to a posterior NTD. Moreover, we found that Fkbp8 knockout mouse embryos have abnormal expression of Wnt3a and Nkx2.9 during the early stage of neural tube development, perhaps also contributing to caudal specific NTDs. These findings provide evidence that functional variants of FKBP8 are risk factors for SB, which may involve a novel mechanism by which Fkbp8 mutations specifically cause SB in mice.
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Affiliation(s)
- Tian Tian
- Institute of Reproductive and Child Health, National Health Commission Key Laboratory of Reproductive Health, Peking University, Beijing 100191, China.,Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA
| | - Xuanye Cao
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA
| | - Sung-Eun Kim
- Department of Pediatrics, The University of Texas at Austin Dell Medical School, Austin, TX 78723, USA
| | - Ying Linda Lin
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA
| | - John W Steele
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA
| | - Robert M Cabrera
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA
| | - Menuka Karki
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA
| | - Wei Yang
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nicholas J Marini
- Department of Molecular and Cellular Biology, California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA
| | - Ethan N Hoffman
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA
| | - Xiao Han
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA
| | - Cindy Hu
- Department of Pediatrics, The University of Texas at Austin Dell Medical School, Austin, TX 78723, USA
| | - Linlin Wang
- Institute of Reproductive and Child Health, National Health Commission Key Laboratory of Reproductive Health, Peking University, Beijing 100191, China
| | - Bogdan J Wlodarczyk
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA
| | - Gary M Shaw
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Aiguo Ren
- Institute of Reproductive and Child Health, National Health Commission Key Laboratory of Reproductive Health, Peking University, Beijing 100191, China
| | - Richard H Finnell
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA.,Departments of Molecular and Human Genetics and Medicine, Baylor College of Medicine, Houston, TX 77031, USA
| | - Yunping Lei
- Center for Precision Environmental Health, Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77031, USA
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10
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Li Y, Li Z. Potential Mechanism Underlying the Role of Mitochondria in Breast Cancer Drug Resistance and Its Related Treatment Prospects. Front Oncol 2021; 11:629614. [PMID: 33816265 PMCID: PMC8013997 DOI: 10.3389/fonc.2021.629614] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 03/03/2021] [Indexed: 12/22/2022] Open
Abstract
Breast cancer incidence and mortality rates have been consistently high among women. The use of diverse therapeutic strategies, including chemotherapy, endocrine therapy, targeted therapy, and immunotherapy, has improved breast cancer prognosis. However, drug resistance has become a tremendous obstacle in overcoming breast cancer recurrence and metastasis. It is known that mitochondria play an important role in carcinoma cell growth, invasion and apoptosis. Recent studies have explored the involvement of mitochondrial metabolism in breast cancer prognosis. Here, we will provide an overview of studies that investigated mitochondrial metabolism pathways in breast cancer treatment resistance, and discuss the application prospects of agents targeting mitochondrial pathways against drug-resistant breast cancer.
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Affiliation(s)
- Yuefeng Li
- Department of Oncological Surgery, Shaoxing Second Hospital, Shaoxing, China
| | - Zhian Li
- Department of Oncological Surgery, Shaoxing Second Hospital, Shaoxing, China
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11
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Lalier L, Mignard V, Joalland MP, Lanoé D, Cartron PF, Manon S, Vallette FM. TOM20-mediated transfer of Bcl2 from ER to MAM and mitochondria upon induction of apoptosis. Cell Death Dis 2021; 12:182. [PMID: 33589622 PMCID: PMC7884705 DOI: 10.1038/s41419-021-03471-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 01/11/2021] [Accepted: 01/21/2021] [Indexed: 12/20/2022]
Abstract
In this work, we have explored the subcellular localization of Bcl2, a major antiapoptotic protein. In U251 glioma cells, we found that Bcl2 is localized mainly in the ER and is translocated to MAM and mitochondria upon induction of apoptosis; this mitochondrial transfer was not restricted to the demonstrator cell line, even if cell-specific modulations exist. We found that the Bcl2/mitochondria interaction is controlled by TOM20, a protein that belongs to the protein import machinery of the mitochondrial outer membrane. The expression of a small domain of interaction of TOM20 with Bcl2 potentiates its anti-apoptotic properties, which suggests that the Bcl2–TOM20 interaction is proapoptotic. The role of MAM and TOM20 in Bcl2 apoptotic mitochondrial localization and function has been confirmed in a yeast model in which the ER–mitochondria encounter structure (ERMES) complex (required for MAM stability in yeast) has been disrupted. Bcl2–TOM20 interaction is thus an additional player in the control of apoptosis.
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Affiliation(s)
- Lisenn Lalier
- CRCINA, INSERM, Université d'Angers, Université de Nantes, Nantes, France.,LaBCT, ICO, Saint Herblain, France
| | - Vincent Mignard
- CRCINA, INSERM, Université d'Angers, Université de Nantes, Nantes, France.,LaBCT, ICO, Saint Herblain, France
| | - Marie-Pierre Joalland
- CRCINA, INSERM, Université d'Angers, Université de Nantes, Nantes, France.,LaBCT, ICO, Saint Herblain, France
| | - Didier Lanoé
- CRCINA, INSERM, Université d'Angers, Université de Nantes, Nantes, France.,LaBCT, ICO, Saint Herblain, France
| | - Pierre-François Cartron
- CRCINA, INSERM, Université d'Angers, Université de Nantes, Nantes, France.,LaBCT, ICO, Saint Herblain, France
| | - Stéphen Manon
- Institut de Biochimie et de Génétique Cellulaires, UMR 5095 CNRS & Université de Bordeaux, Bordeaux, France
| | - François M Vallette
- CRCINA, INSERM, Université d'Angers, Université de Nantes, Nantes, France. .,LaBCT, ICO, Saint Herblain, France.
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12
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Castro-Gonzalez S, Shi Y, Colomer-Lluch M, Song Y, Mowery K, Almodovar S, Bansal A, Kirchhoff F, Sparrer K, Liang C, Serra-Moreno R. HIV-1 Nef counteracts autophagy restriction by enhancing the association between BECN1 and its inhibitor BCL2 in a PRKN-dependent manner. Autophagy 2021; 17:553-577. [PMID: 32097085 PMCID: PMC8007141 DOI: 10.1080/15548627.2020.1725401] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 01/20/2020] [Accepted: 01/24/2020] [Indexed: 12/20/2022] Open
Abstract
Macroautophagy/autophagy is an auto-digestive pro-survival pathway activated in response to stress to target cargo for lysosomal degradation. In recent years, autophagy has become prominent as an innate antiviral defense mechanism through multiple processes, such as targeting virions and viral components for elimination. These exciting findings have encouraged studies on the ability of autophagy to restrict HIV. However, the role of autophagy in HIV infection remains unclear. Whereas some reports indicate that autophagy is detrimental for HIV, others have claimed that HIV deliberately activates this pathway to increase its infectivity. Moreover, these contrasting findings seem to depend on the cell type investigated. Here, we show that autophagy poses a hurdle for HIV replication, significantly reducing virion production. However, HIV-1 uses its accessory protein Nef to counteract this restriction. Previous studies have indicated that Nef affects autophagy maturation by preventing the fusion between autophagosomes and lysosomes. Here, we uncover that Nef additionally blocks autophagy initiation by enhancing the association between BECN1 and its inhibitor BCL2, and this activity depends on the cellular E3 ligase PRKN. Remarkably, the ability of Nef to counteract the autophagy block is more frequently observed in pandemic HIV-1 and its simian precursor SIVcpz infecting chimpanzees than in HIV-2 and its precursor SIVsmm infecting sooty mangabeys. In summary, our findings demonstrate that HIV-1 is susceptible to autophagy restriction and define Nef as the primary autophagy antagonist of this antiviral process.Abbreviations: 3-MA: 3-methyladenine; ACTB: actin, beta; ATG16L1: autophagy related 16 like 1; BCL2: bcl2 apoptosis regulator; BECN1: beclin 1; cDNA: complementary DNA; EGFP: enhanced green fluorescence protein; ER: endoplasmic reticulum; Gag/p55: group-specific antigen; GFP: green fluorescence protein; GST: glutathione S transferase; HA: hemagglutinin; HIV: human immunodeficiency virus; IP: immunoprecipitation; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; Nef: negative factor; PRKN: parkin RBR E3 ubiquitin ligase; PtdIns3K: phosphatidylinositol 3 kinase; PtdIns3P: phosphatidylinositol 3 phosphate; PTM: post-translational modification; RT-qPCR: reverse transcription followed by quantitative PCR; RUBCN: rubicon autophagy regulator; SEM: standard error of the mean; SERINC3: serine incorporator 3; SERINC5: serine incorporator 5; SIV: simian immunodeficiency virus; SQSTM1/p62: sequestosome 1; TFEB: transcription factor EB; UVRAG: UV radiation resistance associated gene; VSV: vesicular stomatitis virus; ZFYVE1/DFCP1: zinc finger FYVE-type containing 1.
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Affiliation(s)
- Sergio Castro-Gonzalez
- Biological Sciences, College of Arts and Sciences, Texas Tech University, Lubbock, TX, USA
| | - Yuhang Shi
- Biological Sciences, College of Arts and Sciences, Texas Tech University, Lubbock, TX, USA
| | - Marta Colomer-Lluch
- IrsiCaixa AIDS Research Institute, Germans Trias i Pujol Research Institute, Badalona, Spain
| | - Ying Song
- Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Kaitlyn Mowery
- Biological Sciences, College of Arts and Sciences, Texas Tech University, Lubbock, TX, USA
| | - Sharilyn Almodovar
- Immunology and Molecular Microbiology, Texas Tech Health Sciences Center, Lubbock, TX, USA
| | - Anju Bansal
- Medicine, Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Frank Kirchhoff
- Institute of Molecular Virology, University of Ulm, Ulm, Germany
| | | | - Chengyu Liang
- Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Ruth Serra-Moreno
- Biological Sciences, College of Arts and Sciences, Texas Tech University, Lubbock, TX, USA
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13
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Gu Y, Ren K, Wang L, Jiang C, Yao Q. Rg1 in combination with mannitol protects neurons against glutamate-induced ER stress via the PERK-eIF2 α-ATF4 signaling pathway. Life Sci 2020; 263:118559. [PMID: 33038374 DOI: 10.1016/j.lfs.2020.118559] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 09/14/2020] [Accepted: 09/29/2020] [Indexed: 12/14/2022]
Abstract
AIMS Ginseng and ginsenosides are known for their remarkable effects on the central nervous system. However, pharmacokinetic studies have suggested that the Ginsenoside Rg1 (Rg1) cannot be efficiently transported through the blood-brain barrier. To investigate the effects of Rg1 in combination with mannitol protects neurons against glutamate-induced ER stress via the PERK-eIF2 -ATF4 signaling pathway. MAIN METHODS Rg1, along with the BBB permeabilizer mannitol, exhibited a potent neuroprotective effect by significantly reducing the neurological scores and infarct volume in rats exposed to middle cerebral artery occlusion. We evaluated the effect of Rg1 on neuroprotection after MCAO, and also explored its potential mechanism of action. KEY FINDINGS Our results show that Rg1 reduced the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive neurons. This neuroprotection may be dependent, at least in part, on the preservation of the endoplasmic reticulum and mitochondrial function. Ischemia-induced brain injury is largely caused by the excessive release of glutamate, which results in excitotoxicity and cell death. Neurons were pretreated with Rg1 before inducing endoplasmic reticulum stress with glutamate. A reduction in the expression of Bax and a concomitant increase in Bcl2 expression prevented the induction of apoptosis. Furthermore, Rg1 downregulated the expression of endoplasmic reticulum stress genes. SIGNIFICANCE Our results indicate that Rg1 modulation of stress-responsive genes helps prevent glutamate-induced endoplasmic reticulum stress in neurons through the PERK-eIF2-α-ATF4 signaling pathway.
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Affiliation(s)
- Yanqing Gu
- Department of Orthopedics, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Kewei Ren
- Department of Orthopedics, the Affiliated Jiangyin Hospital of Southeast University Medical School, Jiangyin, China
| | - Liming Wang
- Department of Orthopedics, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China; Cartilage Regeneration Center, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China; Digital Medicine Institute, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Chunzhi Jiang
- Department of Orthopedics, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China.
| | - Qingqiang Yao
- Department of Orthopedics, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China; Cartilage Regeneration Center, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China; Digital Medicine Institute, Nanjing Medical University, Nanjing, Jiangsu, China.
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14
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Orozco SL, Daniels BP, Yatim N, Messmer MN, Quarato G, Chen-Harris H, Cullen SP, Snyder AG, Ralli-Jain P, Frase S, Tait SWG, Green DR, Albert ML, Oberst A. RIPK3 Activation Leads to Cytokine Synthesis that Continues after Loss of Cell Membrane Integrity. Cell Rep 2020; 28:2275-2287.e5. [PMID: 31461645 DOI: 10.1016/j.celrep.2019.07.077] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 05/10/2019] [Accepted: 07/22/2019] [Indexed: 11/26/2022] Open
Abstract
Necroptosis is a form of programmed cell death that is defined by activation of the kinase RIPK3 and subsequent cell membrane permeabilization by the effector MLKL. RIPK3 activation can also promote immune responses via production of cytokines and chemokines. How active cytokine production is coordinated with the terminal process of necroptosis is unclear. Here, we report that cytokine production continues within necroptotic cells even after they have lost cell membrane integrity and irreversibly committed to death. This continued cytokine production is dependent on mRNA translation and requires maintenance of endoplasmic reticulum integrity that remains after plasma membrane integrity is lost. The continued translation of cytokines by cellular corpses contributes to necroptotic cell uptake by innate immune cells and priming of adaptive immune responses to antigens associated with necroptotic corpses. These findings imply that cell death and production of inflammatory mediators are coordinated to optimize the immunogenicity of necroptotic cells.
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Affiliation(s)
- Susana L Orozco
- Department of Immunology, University of Washington, Seattle, WA 98109, USA; Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98109, USA
| | - Brian P Daniels
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Nader Yatim
- Department of Immunology, Pasteur Institute, 75724 Paris, France
| | - Michelle N Messmer
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Giovanni Quarato
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Haiyin Chen-Harris
- Department of Cancer Immunology, Genentech, Inc., South San Francisco, CA 94080, USA
| | - Sean P Cullen
- Department of Cancer Immunology, Genentech, Inc., South San Francisco, CA 94080, USA
| | - Annelise G Snyder
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Pooja Ralli-Jain
- Department of Immunology, University of Washington, Seattle, WA 98109, USA
| | - Sharon Frase
- Cell and Tissue Imaging Center, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Stephen W G Tait
- Cancer Research UK Beatson Institute, Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1BD, UK
| | - Douglas R Green
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Matthew L Albert
- Department of Cancer Immunology, Genentech, Inc., South San Francisco, CA 94080, USA
| | - Andrew Oberst
- Department of Immunology, University of Washington, Seattle, WA 98109, USA.
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15
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Lunova M, Smolková B, Uzhytchak M, Janoušková KŽ, Jirsa M, Egorova D, Kulikov A, Kubinová Š, Dejneka A, Lunov O. Light-induced modulation of the mitochondrial respiratory chain activity: possibilities and limitations. Cell Mol Life Sci 2020; 77:2815-2838. [PMID: 31583425 PMCID: PMC11104903 DOI: 10.1007/s00018-019-03321-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/11/2019] [Accepted: 09/23/2019] [Indexed: 12/17/2022]
Abstract
Biological effects of high fluence low-power (HFLP) lasers have been reported for some time, yet the molecular mechanisms procuring cellular responses remain obscure. A better understanding of the effects of HFLP lasers on living cells will be instrumental for the development of new experimental and therapeutic strategies. Therefore, we investigated sub-cellular mechanisms involved in the laser interaction with human hepatic cell lines. We show that mitochondria serve as sub-cellular "sensor" and "effector" of laser light non-specific interactions with cells. We demonstrated that despite blue and red laser irradiation results in similar apoptotic death, cellular signaling and kinetic of biochemical responses are distinct. Based on our data, we concluded that blue laser irradiation inhibited cytochrome c oxidase activity in electron transport chain of mitochondria. Contrary, red laser triggered cytochrome c oxidase excessive activation. Moreover, we showed that Bcl-2 protein inhibited laser-induced toxicity by stabilizing mitochondria membrane potential. Thus, cells that either overexpress or have elevated levels of Bcl-2 are protected from laser-induced cytotoxicity. Our findings reveal the mechanism how HFLP laser irradiation interfere with cell homeostasis and underscore that such laser irradiation permits remote control of mitochondrial function in the absence of chemical or biological agents.
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Affiliation(s)
- Mariia Lunova
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic
- Institute for Clinical and Experimental Medicine (IKEM), 14021, Prague, Czech Republic
| | - Barbora Smolková
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic
| | - Mariia Uzhytchak
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic
| | - Klára Žofie Janoušková
- Institute for Clinical and Experimental Medicine (IKEM), 14021, Prague, Czech Republic
- First Faculty of Medicine, Charles University, 12108, Prague, Czech Republic
| | - Milan Jirsa
- Institute for Clinical and Experimental Medicine (IKEM), 14021, Prague, Czech Republic
| | | | | | - Šárka Kubinová
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic
- Institute of Experimental Medicine, Czech Academy of Sciences, 14220, Prague, Czech Republic
| | - Alexandr Dejneka
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic
| | - Oleg Lunov
- Institute of Physics, Czech Academy of Sciences, 18221, Prague, Czech Republic.
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16
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Bogner C, Kale J, Pogmore J, Chi X, Shamas-Din A, Fradin C, Leber B, Andrews DW. Allosteric Regulation of BH3 Proteins in Bcl-x L Complexes Enables Switch-like Activation of Bax. Mol Cell 2020; 77:901-912.e9. [PMID: 32001105 DOI: 10.1016/j.molcel.2019.12.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 09/17/2019] [Accepted: 12/20/2019] [Indexed: 01/01/2023]
Abstract
Current models of apoptosis regulation by the Bcl-2 family of proteins postulate that heterodimeric interactions between family members determine whether Bax and Bak are activated to trigger cell death. Thus, the relative abundance and binding affinities between pro- and anti-apoptotic proteins determines the outcome of these interactions. Examination of these interactions using purified mitochondria and liposomes with full-length recombinant proteins revealed that Bcl-xL inhibits apoptosis as a higher-order complex that binds multiple BH3 proteins. Allosteric regulation of this complex by the BH3 sensitizer Bad confers switch-like activity to the indirect activation of Bax. The BH3 activator cBid sequestered by Bcl-xL complexes changes from an inactive to an active form while bound to a Bcl-xL complex only when Bad is also bound. Bcl-xL complexes enable Bad to function as a non-competitive inhibitor of Bcl-xL and allosterically activate cBid, dramatically enhancing the pro-apoptotic potency of Bad.
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Affiliation(s)
- Christian Bogner
- Sunnybrook Research Institute, University of Toronto, Toronto, ON M5S 1A1, Canada; Third Department of Medicine, Klinikum Rechts der Isar, Technische Universität München, München 80333, Germany
| | - Justin Kale
- Sunnybrook Research Institute, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Justin Pogmore
- Sunnybrook Research Institute, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Xiaoke Chi
- Sunnybrook Research Institute, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Aisha Shamas-Din
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2C1, Canada
| | - Cécile Fradin
- Departments of Biomedical Sciences and Biochemistry, McMaster University, Hamilton, ON L8S 4L8, Canada; Departments of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Brian Leber
- Departments of Biomedical Sciences and Biochemistry, McMaster University, Hamilton, ON L8S 4L8, Canada; Department of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - David W Andrews
- Sunnybrook Research Institute, University of Toronto, Toronto, ON M5S 1A1, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5S 1A1, Canada; Departments of Biomedical Sciences and Biochemistry, McMaster University, Hamilton, ON L8S 4L8, Canada.
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17
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Henry MN, MacDonald MA, Orellana CA, Gray PP, Gillard M, Baker K, Nielsen LK, Marcellin E, Mahler S, Martínez VS. Attenuating apoptosis in Chinese hamster ovary cells for improved biopharmaceutical production. Biotechnol Bioeng 2020; 117:1187-1203. [DOI: 10.1002/bit.27269] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 11/25/2019] [Accepted: 01/04/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Matthew N. Henry
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
| | - Michael A. MacDonald
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
| | - Camila A. Orellana
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
| | - Peter P. Gray
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
| | - Marianne Gillard
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
| | - Kym Baker
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
- Patheon Biologics—A Part of Thermo Fisher Scientific Brisbane Queensland Australia
| | - Lars K. Nielsen
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
- Metabolomics Australia The University of Queensland Brisbane Queensland Australia
- The Novo Nordisk Foundation Center for Biosustainability Technical University of Denmark Kgs. Lyngby Denmark
| | - Esteban Marcellin
- Australian Institute for Bioengineering and Nanotechnology (AIBN) The University of Queensland Brisbane Queensland Australia
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
- Metabolomics Australia The University of Queensland Brisbane Queensland Australia
| | - Stephen Mahler
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
| | - Verónica S. Martínez
- ARC Training Centre for Biopharmaceutical Innovation (CBI) Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland Brisbane Queensland Australia
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18
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Sun X, Angelastro JM, Merino D, Zhou Q, Siegelin MD, Greene LA. Dominant-negative ATF5 rapidly depletes survivin in tumor cells. Cell Death Dis 2019; 10:709. [PMID: 31551409 PMCID: PMC6760124 DOI: 10.1038/s41419-019-1872-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 07/22/2019] [Accepted: 08/08/2019] [Indexed: 12/12/2022]
Abstract
Survivin (BIRC5, product of the BIRC5 gene) is highly expressed in many tumor types and has been widely identified as a potential target for cancer therapy. However, effective anti-survivin drugs remain to be developed. Here we report that both vector-delivered and cell-penetrating dominant-negative (dn) forms of the transcription factor ATF5 that promote selective death of cancer cells in vitro and in vivo cause survivin depletion in tumor cell lines of varying origins. dn-ATF5 decreases levels of both survivin mRNA and protein. The depletion of survivin protein appears to be driven at least in part by enhanced proteasomal turnover and depletion of the deubiquitinase USP9X. Survivin loss is rapid and precedes the onset of cell death triggered by dn-ATF5. Although survivin downregulation is sufficient to drive tumor cell death, survivin over-expression does not rescue cancer cells from dn-ATF5-promoted apoptosis. This indicates that dn-ATF5 kills malignant cells by multiple mechanisms that include, but are not limited to, survivin depletion. Cell-penetrating forms of dn-ATF5 are currently being developed for potential therapeutic use and the present findings suggest that they may pose an advantage over treatments that target only survivin.
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Affiliation(s)
- Xiaotian Sun
- Department of Pathology and Cell Biology, Columbia University, New York, NY, 10032, USA
| | - James M Angelastro
- Department of Molecular Biosciences, University of California, Davis School of Veterinary Medicine, Davis, CA, 95616, USA
| | - David Merino
- Department of Pathology and Cell Biology, Columbia University, New York, NY, 10032, USA.,CMI Strategies, Boulogne-Billancourt, 80 rue Gallieni, cedex, France
| | - Qing Zhou
- Department of Pathology and Cell Biology, Columbia University, New York, NY, 10032, USA
| | - Markus D Siegelin
- Department of Pathology and Cell Biology, Columbia University, New York, NY, 10032, USA
| | - Lloyd A Greene
- Department of Pathology and Cell Biology, Columbia University, New York, NY, 10032, USA.
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19
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Distelhorst CW, Bootman MD. Creating a New Cancer Therapeutic Agent by Targeting the Interaction between Bcl-2 and IP 3 Receptors. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a035196. [PMID: 31110129 DOI: 10.1101/cshperspect.a035196] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Bcl-2 is a member of a family of proteins that regulate cell survival. Expression of Bcl-2 is aberrantly elevated in many types of cancer. Within cells of the immune system, Bcl-2 has a physiological role in regulating immune responses. However, in cancers arising from cells of the immune system Bcl-2 promotes cell survival and proliferation. This review summarizes discoveries over the past 30 years that have elucidated Bcl-2's role in the normal immune system, including its actions in regulating calcium (Ca2+) signals necessary for the immune response, and for Ca2+-mediated apoptosis at the end of an immune response. How Bcl-2 modulates the release of Ca2+ from intracellular stores via inositol 1,4,5-trisphosphate receptors (IP3R) is discussed, and in particular, the role of Bcl-2/IP3R interactions in promoting the survival of cancer cells by preventing Ca2+-mediated cell death. The development and usage of a peptide, referred to as TAT-Pep8, or more recently, BIRD-2, that induces death of cancer cells by inhibiting Bcl-2's control over IP3R-mediated Ca2+ elevation is discussed. Studies aimed at discovering a small molecule that mimics BIRD-2's anticancer mechanism of action are summarized, along with the prospect of such a compound becoming a novel therapeutic option for cancer.
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Affiliation(s)
- Clark W Distelhorst
- Departments of Medicine and Pharmacology, Case Western Reserve University School of Medicine, University Hospitals Cleveland Medical Center, Cleveland, Ohio 44106, USA
| | - Martin D Bootman
- School of Life, Health, and Chemical Science, The Open University, Milton Keynes MK7 6AA, United Kingdom
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20
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Simpson JD, Ediriweera GR, Howard CB, Fletcher NL, Bell CA, Thurecht KJ. Polymer design and component selection contribute to uptake, distribution & trafficking behaviours of polyethylene glycol hyperbranched polymers in live MDA-MB-468 breast cancer cells. Biomater Sci 2019; 7:4661-4674. [PMID: 31469127 DOI: 10.1039/c9bm00957d] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
As polymeric nanomedicines grow increasingly complex in design, an effective therapeutic release is often inherently tied to localisation to specific intracellular compartments or microenvironments. The inclusion of environmentally-sensitive moieties links the functionality of such materials to the trafficking behaviours exhibited once materials have obtained access to the cellular milieu. In order to perform their designed function, such materials often need to encounter specific biological cues or stimuli. As such, there is an increased need to improve our understanding of how the physicochemical properties of nanomaterials influence post-internalisation behaviours. Amongst the unknown factors that may contribute to the trafficking behaviours and distribution of polymers within the cellular environment, is the influence of the components selected in the development of such materials. To examine whether composition and arrangement of components within small polymeric nanomaterials contribute to their ability to navigate the intracellular space, here we utilise fluorophores to model component selection, varying the fluorescent handle selected and its method of incorporation. We explore the intracellular behaviours of well-characterised hyperbranched polymers in live MDA-MB-468 breast cancer cells in vitro. Changes in distribution as a function of both fluorophore selection and placement are reported, and our data suggest that the individual components used to produce potential nanomedicines are critical to their overall functioning and efficacy. Further to this, through the use of a novel non-conjugated targeting ligand, we demonstrate that there is inherent competition between component-directing factors and cellular influences on the ultimate fate of the polymers. The behaviours reported here suggest that not only does component selection contribute to intracellular processing, but these factors could potentially be harnessed when designing polymers to ensure improved functionality of future materials for therapeutic delivery.
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Affiliation(s)
- Joshua D Simpson
- Centre for Advanced Imaging (CAI), The University of Queensland, Brisbane, QLD 4072, Australia. and Australian Institute for Bioengineering & Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia and ARC Centre of Excellence for Convergent Bio-Nano Science & Technology and ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Gayathri R Ediriweera
- Centre for Advanced Imaging (CAI), The University of Queensland, Brisbane, QLD 4072, Australia. and Australian Institute for Bioengineering & Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia and ARC Centre of Excellence for Convergent Bio-Nano Science & Technology and ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Christopher B Howard
- Centre for Advanced Imaging (CAI), The University of Queensland, Brisbane, QLD 4072, Australia. and Australian Institute for Bioengineering & Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia and ARC Centre of Excellence for Convergent Bio-Nano Science & Technology and ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Nicholas L Fletcher
- Centre for Advanced Imaging (CAI), The University of Queensland, Brisbane, QLD 4072, Australia. and Australian Institute for Bioengineering & Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia and ARC Centre of Excellence for Convergent Bio-Nano Science & Technology and ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Craig A Bell
- Centre for Advanced Imaging (CAI), The University of Queensland, Brisbane, QLD 4072, Australia. and Australian Institute for Bioengineering & Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia and ARC Centre of Excellence for Convergent Bio-Nano Science & Technology and ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Kristofer J Thurecht
- Centre for Advanced Imaging (CAI), The University of Queensland, Brisbane, QLD 4072, Australia. and Australian Institute for Bioengineering & Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia and ARC Centre of Excellence for Convergent Bio-Nano Science & Technology and ARC Training Centre for Innovation in Biomedical Imaging Technology, The University of Queensland, Brisbane, QLD 4072, Australia
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21
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Gayle SS, Sahni JM, Webb BM, Weber-Bonk KL, Shively MS, Spina R, Bar EE, Summers MK, Keri RA. Targeting BCL-xL improves the efficacy of bromodomain and extra-terminal protein inhibitors in triple-negative breast cancer by eliciting the death of senescent cells. J Biol Chem 2018; 294:875-886. [PMID: 30482844 DOI: 10.1074/jbc.ra118.004712] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 10/24/2018] [Indexed: 12/13/2022] Open
Abstract
Inhibitors of bromodomain and extra-terminal proteins (BETi) suppress oncogenic gene expression and have been shown to be efficacious in many in vitro and murine models of cancer, including triple-negative breast cancer (TNBC), a highly aggressive disease. However, in most cancer models, responses to BETi can be highly variable. We previously reported that TNBC cells either undergo senescence or apoptosis in response to BETi, but the specific mechanisms dictating these two cell fates remain unknown. Using six human TNBC cell lines, we show that the terminal response of TNBC cells to BETi is dictated by the intrinsic expression levels of the anti-apoptotic protein B-cell lymphoma-extra large (BCL-xL). BCL-xL levels were higher in cell lines that senesce in response to BETi compared with lines that primarily die in response to these drugs. Moreover, BCL-xL expression was further reduced in cells that undergo BETi-mediated apoptosis. Forced BCL-xL overexpression in cells that normally undergo apoptosis following BETi treatment shifted them to senescence without affecting the reported mechanism of action of BETi in TNBC, that is, mitotic catastrophe. Most importantly, pharmacological or genetic inhibition of BCL-xL induced apoptosis in response to BETi, and inhibiting BCL-xL, even after BETi-induced senescence had already occurred, still induced cell death. These results indicate that BCL-xL provides a senescent cell death-inducing or senolytic target that may be exploited to improve therapeutic outcomes of TNBC in response to BETi. They also suggest that the basal levels of BCL-xL should be predictive of tumor responses to BETi in current clinical trials.
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Affiliation(s)
| | | | | | | | | | | | | | - Mathew K Summers
- Department of Radiation Oncology and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210
| | - Ruth A Keri
- From the Departments of Pharmacology, .,Genetics and Genome Sciences and Division of General Medical Sciences-Oncology, Case Western Reserve University, Cleveland, Ohio 44106 and
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22
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Misoprostol regulates Bnip3 repression and alternative splicing to control cellular calcium homeostasis during hypoxic stress. Cell Death Discov 2018; 4:37. [PMID: 30275982 PMCID: PMC6155004 DOI: 10.1038/s41420-018-0104-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 08/05/2018] [Accepted: 08/05/2018] [Indexed: 12/15/2022] Open
Abstract
The cellular response to hypoxia involves the activation of a conserved pathway for gene expression regulated by the transcription factor complex called hypoxia-inducible factor (HIF). This pathway has been implicated in both the adaptive response to hypoxia and in several hypoxic-ischemic-related pathologies. Perinatal hypoxic injury, often associated with prematurity, leads to multi-organ dysfunction resulting in significant morbidity and mortality. Using a rodent model of neonatal hypoxia and several representative cell lines, we observed HIF1α activation and down-stream induction of the cell death gene Bnip3 in brain, large intestine, and heart which was mitigated by administration of the prostaglandin E1 analog misoprostol. Mechanistically, we determined that misoprostol inhibits full-length Bnip3 (Bnip3-FL) expression through PKA-mediated NF-κB (P65) nuclear retention, and the induction of pro-survival splice variants. We observed that the dominant small pro-survival variant of Bnip3 in mouse cells lacks the third exon (Bnip3ΔExon3), whereas human cells produce a pro-survival BNIP3 variant lacking exon 2 (BNIP3ΔExon2). In addition, these small Bnip3 splice variants prevent mitochondrial dysfunction, permeability transition, and necrosis triggered by Bnip3-FL by blocking calcium transfer from the sarco/endoplasmic reticulum to the mitochondria. Furthermore, misoprostol and Bnip3ΔExon3 promote nuclear calcium accumulation, resulting in HDAC5 nuclear export, NFAT activation, and adaptive changes in cell morphology and gene expression. Collectively, our data suggests that misoprostol can mitigate the potential damaging effects of hypoxia on multiple cell types by activating adaptive cell survival pathways through Bnip3 repression and alternative splicing.
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23
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Navarro SD, Pessatto LR, Meza A, de Oliveira EJT, Auharek SA, Vilela LC, de Lima DP, de Azevedo RB, Kassuya CAL, Cáceres OIA, da Silva Gomes R, Beatriz A, Oliveira RJ, Martines MAU. Resorcinolic lipid 3-heptyl-3,4,6-trimethoxy-3H-isobenzofuran-1-one is a strategy for melanoma treatment. Life Sci 2018; 209:300-312. [PMID: 30102904 DOI: 10.1016/j.lfs.2018.08.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 08/02/2018] [Accepted: 08/08/2018] [Indexed: 12/12/2022]
Abstract
AIMS Previous studies performed by our research group indicated that cytosporone analogues are capable of prevent or repair DNA damages. This work presents the evaluation of the activity of AMS35AA for metastatic murine melanoma cells (B16F10) in experimental model in vitro and, in pre-clinic assay of metastatic melanoma in vivo, using mice lineage C57BL/6. MAIN METHODS In vitro assays were performed: MTT and comet assay, flow cytometry evaluation, gene expression assay by RT-PCR, qualitative evaluation of cell death using B16F10 cells. In vivo assays: micronucleus and comet assay, splenic phagocytosis, melanoma murine model and histopathological analysis, using mice lineage C57BL/6 (n = 20). KEY FINDINGS In vitro results performed by MTT assay showed that AMS35AA is cytotoxic for B16F10 cells (p < 0.05). Based on comet assay the genotoxicity of the IC50 was determined (95.83 μg/mL) (p < 0.05). These data were corroborated by flow cytometry analysis after the treatment with AMS35AA, which indicates the cellular death by apoptosis (p < 0.05) and increasing of ATR, p53, p21 and GADD45 gene expressions verified using RT-PCR. With respect to in vivo results, it was observed that AMS35AA did not show genotoxic activity. Data of tumor volume ex vivo indicate reduction of tumor for the treated animals with AMS35AA up to 15.84×, which is superior to Dacarbazina (50 mg/Kg, p.c.; i.p.). SIGNIFICANCE In summary, the study showed that AMS35AA reveals relevant results regarding to cytotoxicity of B16F10 murine melanoma cells, inducing death by apoptosis via mitochondrial and/or mediated by DNA damages.
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Affiliation(s)
- Stephanie Dynczuki Navarro
- Graduate Program in Biotechnology and Biodiversity, Pro Midwest Network, Faculty of Pharmaceutical Sciences, Food and Nutrition, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Lucas Roberto Pessatto
- Research Center in Stem Cells, Cell Therapy and Genetic Toxicology (CeTroGen), "Maria Aparecida Pedrossian" University Hospital, Campo Grande, Mato Grosso do Sul, Brazil; Graduate Program in Genetics and Molecular Biology, General Biology Department, Biological Sciences Center, State University of Londrina, Londrina, Paraná, Brazil
| | - Alisson Meza
- Graduate Program in Chemistry, Chemistry Institute, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Edwin José Torres de Oliveira
- Research Center in Stem Cells, Cell Therapy and Genetic Toxicology (CeTroGen), "Maria Aparecida Pedrossian" University Hospital, Campo Grande, Mato Grosso do Sul, Brazil; Graduate Program in Genetics and Molecular Biology, General Biology Department, Biological Sciences Center, State University of Londrina, Londrina, Paraná, Brazil
| | - Sarah Alves Auharek
- Faculty of Medicine, Federal University of Jequitinhonha and Mucuri Valleys, Teófilo Otoni, Minas Gerais, Brazil
| | - Lizia Colares Vilela
- Faculty of Medicine, Federal University of Jequitinhonha and Mucuri Valleys, Teófilo Otoni, Minas Gerais, Brazil
| | - Dênis Pires de Lima
- Graduate Program in Chemistry, Chemistry Institute, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Ricardo Bentes de Azevedo
- Genetics and Morphology Department, Biosciences Institute, Brasilia University, Brasilia, Federal District, Brazil
| | | | - Osmar Ignacio Ayala Cáceres
- Graduate Program in Chemistry, Chemistry Institute, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Roberto da Silva Gomes
- Graduate Program in Chemistry, Chemistry Institute, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil; Synthesis and Molecular Modification Laboratory, Faculty of Exact Sciences and Technology, Federal University of Grande Dourados, Dourados, Mato Grosso do Sul, Brazil
| | - Adilson Beatriz
- Graduate Program in Chemistry, Chemistry Institute, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil
| | - Rodrigo Juliano Oliveira
- Research Center in Stem Cells, Cell Therapy and Genetic Toxicology (CeTroGen), "Maria Aparecida Pedrossian" University Hospital, Campo Grande, Mato Grosso do Sul, Brazil; Graduate Program in Genetics and Molecular Biology, General Biology Department, Biological Sciences Center, State University of Londrina, Londrina, Paraná, Brazil; Graduate Program in Health and Development of Midwest Region, Faculty of Medicine "Dr Hélio Mandetta", Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil.
| | - Marco Antonio Utrera Martines
- Graduate Program in Biotechnology and Biodiversity, Pro Midwest Network, Faculty of Pharmaceutical Sciences, Food and Nutrition, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil; Graduate Program in Chemistry, Chemistry Institute, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil.
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24
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Distelhorst CW. Targeting Bcl-2-IP 3 receptor interaction to treat cancer: A novel approach inspired by nearly a century treating cancer with adrenal corticosteroid hormones. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1795-1804. [PMID: 30053503 DOI: 10.1016/j.bbamcr.2018.07.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 07/18/2018] [Accepted: 07/19/2018] [Indexed: 12/12/2022]
Abstract
Bcl-2 inhibits cell death by at least two different mechanisms. On the one hand, its BH3 domain binds to pro-apoptotic proteins such as Bim and prevents apoptosis induction. On the other hand, the BH4 domain of Bcl-2 binds to the inositol 1,4,5-trisphosphate receptor (IP3R), preventing Ca2+ signals that mediate cell death. In normal T-cells, Bcl-2 levels increase during the immune response, protecting against cell death, and then decline as apoptosis ensues and the immune response dissipates. But in many cancers Bcl-2 is aberrantly expressed and exploited to prevent cell death by inhibiting IP3R-mediated Ca2+ elevation. This review summarizes what is known about the mechanism of Bcl-2's control over IP3R-mediated Ca2+ release and cell death induction. Early insights into the role of Ca2+ elevation in corticosteroid-mediated cell death serves as a model for how targeting IP3R-mediated Ca2+ elevation can be a highly effective therapeutic approach for different types of cancer. Moreover, the successful development of ABT-199 (Venetoclax), a small molecule targeting the BH3 domain of Bcl-2 but without effects on Ca2+, serves as proof of principle that targeting Bcl-2 can be an effective therapeutic approach. BIRD-2, a synthetic peptide that inhibits Bcl-2-IP3R interaction, induces cell death induction in ABT-199 (Venetoclax)-resistant cancer models, attesting to the value of developing therapeutic agents that selectively target Bcl-2-IP3R interaction, inducing Ca2+-mediated cell death.
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Affiliation(s)
- Clark W Distelhorst
- Case Western University School of Medicine, Case Comprehensive Cancer Center, University Hospitals Cleveland Medical Center, Cleveland, OH 44106, United States of America.
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25
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Oing C, Tennstedt P, Simon R, Volquardsen J, Borgmann K, Bokemeyer C, Petersen C, Dikomey E, Rothkamm K, Mansour WY. BCL2-overexpressing prostate cancer cells rely on PARP1-dependent end-joining and are sensitive to combined PARP inhibitor and radiation therapy. Cancer Lett 2018. [PMID: 29526801 DOI: 10.1016/j.canlet.2018.03.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Here we report that BCL2 blocks DNA double strand break (DSB) repair via nonhomologous end-joining (NHEJ), through sequestration of KU80 protein outside the nucleus. We find that this effect is associated with a repair switch to the error-prone PARP1-dependent end-joining (PARP1-EJ). We present in-vitro proof-of-concept for therapeutic targeting of this switch using PARP inhibitor to specifically enhance the radiosensitivity of BCL2-overexpressing cells. Given its erroneous behavior, PARP1-EJ might allow for the accumulation of genetic alterations and tumor progression. Consistently, we report an inverse correlation between BCL2 expression and biochemical recurrence-free survival of 10.259 prostate cancer (PCa) patients who underwent primary radical-prostatectomy for localized disease. Further, we evaluated retrospectively the impact of BCL2 expression on clinical outcome of 1.426 PCa patients, who had been given salvage radiotherapy at relapse after radical prostatectomy. In line with its role in blocking NHEJ, BCL2 over-expressers showed significantly better response to salvage radiotherapy compared to low-expressers. Collectively, our findings identify BCL2 status in PCa as a putative predictor of (i) radiotherapy response and (ii) response to treatment with PARP inhibitor olaparib as a radiosensitizing agent.
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Affiliation(s)
- Christoph Oing
- Laboratory of Radiobiology and Experimental Radiation Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Oncology, Hematology and Bone Marrow Transplantation with Section of Pneumology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Pierre Tennstedt
- Martini-Clinic, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Ronald Simon
- Department of Pathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jennifer Volquardsen
- Laboratory of Radiobiology and Experimental Radiation Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kerstin Borgmann
- Laboratory of Radiobiology and Experimental Radiation Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carsten Bokemeyer
- Department of Oncology, Hematology and Bone Marrow Transplantation with Section of Pneumology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Cordula Petersen
- Department of Radiotherapy and Radiooncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ekkehard Dikomey
- Laboratory of Radiobiology and Experimental Radiation Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kai Rothkamm
- Laboratory of Radiobiology and Experimental Radiation Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Wael Y Mansour
- Laboratory of Radiobiology and Experimental Radiation Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Tumor Biology, National Cancer Center, Cairo University, Cairo, Egypt.
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26
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Mughal W, Martens M, Field J, Chapman D, Huang J, Rattan S, Hai Y, Cheung KG, Kereliuk S, West AR, Cole LK, Hatch GM, Diehl-Jones W, Keijzer R, Dolinsky VW, Dixon IM, Parmacek MS, Gordon JW. Myocardin regulates mitochondrial calcium homeostasis and prevents permeability transition. Cell Death Differ 2018; 25:1732-1748. [PMID: 29511336 PMCID: PMC6180099 DOI: 10.1038/s41418-018-0073-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 12/17/2017] [Accepted: 01/15/2018] [Indexed: 01/20/2023] Open
Abstract
Myocardin is a transcriptional co-activator required for cardiovascular development, but also promotes cardiomyocyte survival through an unclear molecular mechanism. Mitochondrial permeability transition is implicated in necrosis, while pore closure is required for mitochondrial maturation during cardiac development. We show that loss of myocardin function leads to subendocardial necrosis at E9.5, concurrent with elevated expression of the death gene Nix. Mechanistically, we demonstrate that myocardin knockdown reduces microRNA-133a levels to allow Nix accumulation, leading to mitochondrial permeability transition, reduced mitochondrial respiration, and necrosis. Myocardin knockdown elicits calcium release from the endo/sarcoplasmic reticulum with mitochondrial calcium accumulation, while restoration of microRNA-133a function, or knockdown of Nix rescues calcium perturbations. We observed reduced myocardin and elevated Nix expression within the infarct border-zone following coronary ligation. These findings identify a myocardin-regulated pathway that maintains calcium homeostasis and mitochondrial function during development, and is attenuated during ischemic heart disease. Given the diverse role of Nix and microRNA-133a, these findings may have broader implications to metabolic disease and cancer.
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Affiliation(s)
- Wajihah Mughal
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada.,Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Matthew Martens
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada.,Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Jared Field
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada.,Department of Biological Science, University of Manitoba, Winnipeg, MB, Canada
| | - Donald Chapman
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada.,Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Jianhe Huang
- Department of Medicine, Penn Cardiovascular Institute, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Sunil Rattan
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada.,Institute of Cardiovascular Sciences, St. Boniface Research Centre, Winnipeg, MB, Canada
| | - Yan Hai
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada.,College of Nursing, University of Manitoba, Winnipeg, MB, Canada
| | - Kyle G Cheung
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada.,Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Stephanie Kereliuk
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada.,Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Adrian R West
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada.,The Biology of Breathing Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Laura K Cole
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada.,Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Grant M Hatch
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada.,Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - William Diehl-Jones
- Department of Biological Science, University of Manitoba, Winnipeg, MB, Canada.,Faculty of Health Disciplines, Athabasca University, Edmonton, MB, Canada
| | - Richard Keijzer
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada.,The Biology of Breathing Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada.,Department of Surgery, University of Manitoba, Winnipeg, MB, Canada
| | - Vernon W Dolinsky
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada.,Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Ian M Dixon
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada.,Institute of Cardiovascular Sciences, St. Boniface Research Centre, Winnipeg, MB, Canada
| | - Michael S Parmacek
- Department of Medicine, Penn Cardiovascular Institute, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Joseph W Gordon
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, MB, Canada. .,Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, MB, Canada. .,College of Nursing, University of Manitoba, Winnipeg, MB, Canada.
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27
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Chiu WT, Chang HA, Lin YH, Lin YS, Chang HT, Lin HH, Huang SC, Tang MJ, Shen MR. Bcl -2 regulates store-operated Ca 2+ entry to modulate ER stress-induced apoptosis. Cell Death Discov 2018. [PMID: 29531834 PMCID: PMC5841437 DOI: 10.1038/s41420-018-0039-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Ca2+ plays a significant role in linking the induction of apoptosis. The key anti-apoptotic protein, Bcl-2, has been reported to regulate the movement of Ca2+ across the ER membrane, but the exact effect of Bcl-2 on Ca2+ levels remains controversial. Store-operated Ca2+ entry (SOCE), a major mode of Ca2+ uptake in non-excitable cells, is activated by depletion of Ca2+ in the ER. Depletion of Ca2+ in the ER causes translocation of the SOC channel activator, STIM1, to the plasma membrane. Thereafter, STIM1 binds to Orai1 or/and TRPC1 channels, forcing them to open and thereby allow Ca2+ entry. In addition, several anti-cancer drugs have been reported to induce apoptosis of cancer cells via the SOCE pathway. However, the detailed mechanism underlying the regulation of SOCE by Bcl-2 is not well understood. In this study, a three-amino acid mutation within the Bcl-2 BH1 domain was generated to verify the role of Bcl-2 in Ca2+ handling during ER stress. The subcellular localization of the Bcl-2 mutant (mt) is similar to that in the wild-type Bcl-2 (WT) in the ER and mitochondria. We found that mt enhanced thapsigargin and tunicamycin-induced apoptosis through ER stress-mediated apoptosis but not through the death receptor- and mitochondria-dependent apoptosis, while WT prevented thapsigargin- and tunicamycin-induced apoptosis. In addition, mt depleted Ca2+ in the ER lumen and also increased the expression of SOCE-related molecules. Therefore, a massive Ca2+ influx via SOCE contributed to caspase activation and apoptosis. Furthermore, inhibiting SOCE or chelating either extracellular or intracellular Ca2+ inhibited mt-mediated apoptosis. In brief, our results explored the critical role of Bcl-2 in Ca2+ homeostasis and the modulation of ER stress.
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Affiliation(s)
- Wen-Tai Chiu
- 1Department of Biomedical Engineering, National Cheng Kung University, Tainan, 701 Taiwan.,2Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, 701 Taiwan
| | - Heng-Ai Chang
- 2Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, 701 Taiwan
| | - Yi-Hsin Lin
- 1Department of Biomedical Engineering, National Cheng Kung University, Tainan, 701 Taiwan
| | - Yu-Shan Lin
- 2Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, 701 Taiwan
| | - Hsiao-Tzu Chang
- 3Department of Pharmacology, National Cheng Kung University, Tainan, 701 Taiwan
| | - Hsi-Hui Lin
- 4Department of Physiology, National Cheng Kung University, Tainan, 701 Taiwan
| | - Soon-Cen Huang
- 5Department of Obstetrics and Gynecology, Chi Mei Medical Center, Liouying Campus, Tainan, 736 Taiwan
| | - Ming-Jer Tang
- 2Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, 701 Taiwan.,4Department of Physiology, National Cheng Kung University, Tainan, 701 Taiwan
| | - Meng-Ru Shen
- 2Institute of Basic Medical Sciences, National Cheng Kung University, Tainan, 701 Taiwan.,3Department of Pharmacology, National Cheng Kung University, Tainan, 701 Taiwan
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28
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The La protein counteracts cisplatin-induced cell death by stimulating protein synthesis of anti-apoptotic factor Bcl2. Oncotarget 2018; 7:29664-76. [PMID: 27105491 PMCID: PMC5045424 DOI: 10.18632/oncotarget.8819] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/28/2016] [Indexed: 02/06/2023] Open
Abstract
Up-regulation of anti-apoptotic factors is a critical mechanism of cancer cell resistance and often counteracts the success of chemotherapeutic treatment. Herein, we identified the cancer-associated RNA-binding protein La as novel factor contributing to cisplatin resistance. Our data demonstrate that depletion of the RNA-binding protein La in head and neck squamous cell carcinoma cells (HNSCC) increases the sensitivity toward cisplatin-induced cell death paralleled by reduced expression of the anti-apoptotic factor Bcl2. Furthermore, it is shown that transient expression of Bcl2 in La-depleted cells protects against cisplatin-induced cell death. By dissecting the underlying mechanism we report herein, that the La protein is required for Bcl2 protein synthesis in cisplatin-treated cells. The RNA chaperone La binds in close proximity to the authentic translation start site and unwinds a secondary structure embedding the authentic AUG. Altogether, our data support a novel model, whereby cancer-associated La protein contributes to cisplatin resistance by stimulating the translation of anti-apoptotic factor Bcl2 in HNSCC cells.
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Schweich LDC, Oliveira EJTD, Pesarini JR, Hermeto LC, Camassola M, Nardi NB, Brochado TMM, Antoniolli-Silva ACMB, Oliveira RJ. All-trans retinoic acid induces mitochondria-mediated apoptosis of human adipose-derived stem cells and affects the balance of the adipogenic differentiation. Biomed Pharmacother 2017; 96:1267-1274. [PMID: 29239820 DOI: 10.1016/j.biopha.2017.11.087] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 11/14/2017] [Accepted: 11/17/2017] [Indexed: 12/20/2022] Open
Abstract
The all-trans-retinoic acid (ATRA) is the most active form of vitamin A that helps to regulate the proliferation, differentiation and apoptosis of several types of cells, mainly the adipocytes, and causes weight loss through the reduction of adipogenesis and lipogenesis. In this present study we demonstrated that ATRA concentrations of 20.75, 50 and 100 μM decreased the cell viability in vitro of human adipose-derived stem cells (ADSCs), and in ADSCs during adipogenic differentiation. The cells cycle assessment showed that ATRA increased the cell frequency in Sub-G1 at 4.02x and decreased it in G1 in 2.54x. Moreover, the membrane integrity loss increased by 4.66x and apoptosis increased by 33.56x in ATRA-treated cultures. The gene expression assay suggested that the treatment using ATRA leads to mitochondrial membrane permeabilization and to consequent release of proapoptotic BAK and BAX molecules (increased expression 5.5 and 5.4x respectively); in addition, it increased CASP3 expression (by 8.8x). These events may activate the Bcl-2 (4.1x increase), GADD45 (increase 3.14x) and PPAR-γ (16x increase) expressions, as well as, to reduce the p53 (by -1.38x) expression; therefore, these events should be further mediated by increased RARα expression (by 3.8x). The results evidenced that ATRA may be a good proposal for mesotherapy strategies in order to control the development of subcutaneous adipose tissue; as this tissue have a higher development in some specific areas and ATRA interferes not only in the ADSCs differentiation but also in the apoptosis of ADSCs, preadipocytes and adipocytes.
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Affiliation(s)
- Laynna de Carvalho Schweich
- Stem Cell, Cell Therapy and Toxicological Genetics Research Centre (CeTroGen), "Maria Aparecida Pedrossian" University Hospital, Brazilian Hospital Services Company (EBSERH), Campo Grande, Mato Grosso do Sul, Brazil; Federal University of Mato Grosso do Sul (UFMS), Graduate Programme in Health and Development in the Central-West Region, School of Medicine (FAMED), Campo Grande, Mato Grosso do Sul, Brazil
| | - Edwin José Torres de Oliveira
- Stem Cell, Cell Therapy and Toxicological Genetics Research Centre (CeTroGen), "Maria Aparecida Pedrossian" University Hospital, Brazilian Hospital Services Company (EBSERH), Campo Grande, Mato Grosso do Sul, Brazil; State University of Londrina (UEL), Graduate Programme in Genetics and Molecular Biology, Department of General Biology, Londrina, Paraná, Brazil
| | - João Renato Pesarini
- Stem Cell, Cell Therapy and Toxicological Genetics Research Centre (CeTroGen), "Maria Aparecida Pedrossian" University Hospital, Brazilian Hospital Services Company (EBSERH), Campo Grande, Mato Grosso do Sul, Brazil; Federal University of Mato Grosso do Sul (UFMS), Graduate Programme in Health and Development in the Central-West Region, School of Medicine (FAMED), Campo Grande, Mato Grosso do Sul, Brazil
| | - Larissa Corrêa Hermeto
- Stem Cell, Cell Therapy and Toxicological Genetics Research Centre (CeTroGen), "Maria Aparecida Pedrossian" University Hospital, Brazilian Hospital Services Company (EBSERH), Campo Grande, Mato Grosso do Sul, Brazil; Federal University of Mato Grosso do Sul (UFMS), Graduate Programme in Veterinary Science, School of Veterinary Medicine and Zootechny, Campo Grande, Mato Grosso do Sul, Brazil
| | - Melissa Camassola
- Lutheran University of Brazil (ULBRA), Laboratory of Stem Cell and Tissue Engineering, Canoas, Rio Grande do Sul, Brazil
| | - Nance Beyer Nardi
- Lutheran University of Brazil (ULBRA), Laboratory of Stem Cell and Tissue Engineering, Canoas, Rio Grande do Sul, Brazil
| | - Themis Maria Milan Brochado
- Brazilian Institute of Therapies and Education (IBRATE), Graduate Programme in Dermatofunctional Physiotherapy, Campo Grande, Mato Grosso do Sul, Brazil
| | - Andréia Conceição Milan Brochado Antoniolli-Silva
- Coordinator of CeTroGen, "Maria Aparecida Pedrossian" University Hospital, Brazilian Hospital Services Company (EBSERH), Campo Grande, Mato Grosso do Sul, Brazil; Associate Professor of Federal University of Mato Grosso do Sul (UFMS) in Graduate Programme in Health and Development in the Central-West Region and School of Medicine (FAMED), Campo Grande, Mato Grosso do Sul, Brazil
| | - Rodrigo Juliano Oliveira
- Stem Cell, Cell Therapy and Toxicological Genetics Research Centre (CeTroGen), "Maria Aparecida Pedrossian" University Hospital, Brazilian Hospital Services Company (EBSERH), Campo Grande, Mato Grosso do Sul, Brazil; Federal University of Mato Grosso do Sul (UFMS), Graduate Programme in Health and Development in the Central-West Region, School of Medicine (FAMED), Campo Grande, Mato Grosso do Sul, Brazil; State University of Londrina (UEL), Graduate Programme in Genetics and Molecular Biology, Department of General Biology, Londrina, Paraná, Brazil.
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Cardamonin inhibits colonic neoplasia through modulation of MicroRNA expression. Sci Rep 2017; 7:13945. [PMID: 29066742 PMCID: PMC5655681 DOI: 10.1038/s41598-017-14253-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 10/09/2017] [Indexed: 12/19/2022] Open
Abstract
Colorectal cancer is currently the third leading cause of cancer related deaths. There is considerable interest in using dietary intervention strategies to prevent chronic diseases including cancer. Cardamonin is a spice derived nutraceutical and herein, for the first time we evaluated the therapeutic benefits of cardamonin in Azoxymethane (AOM) induced mouse model of colorectal cancer. Mice were divided into 4 groups of which three groups were given six weekly injections of AOM. One group served as untreated control and remaining groups were treated with either vehicle or Cardamonin starting from the same day or 16 weeks after the first AOM injection. Cardamonin treatment inhibited the tumor incidence, tumor multiplicity, Ki-67 and β-catenin positive cells. The activation of NF-kB signaling was also abrogated after cardamonin treatment. To elucidate the mechanism of action a global microRNA profiling of colon samples was performed. Computational analysis revealed that there is a differential expression of miRNAs between these groups. Subsequently, we extend our findings to human colorectal cancer and found that cardamonin inhibited the growth, induces cell cycle arrest and apoptosis in human colorectal cancer cell lines. Taken together, our study provides a better understanding of chemopreventive potential of cardamonin in colorectal cancer.
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Lin ML, Chen SS. Activation of Casein Kinase II by Gallic Acid Induces BIK-BAX/BAK-Mediated ER Ca ++-ROS-Dependent Apoptosis of Human Oral Cancer Cells. Front Physiol 2017; 8:761. [PMID: 29033852 PMCID: PMC5627504 DOI: 10.3389/fphys.2017.00761] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 09/19/2017] [Indexed: 01/18/2023] Open
Abstract
Induction of the generation of endoplasmic reticulum (ER) calcium (Ca++)-mediated reactive oxygen species (ROS) by gallic acid (GA) has been implicated in the mitochondrial apoptotic death of human oral cancer (OC) cells, but the molecular mechanism by which GA causes ER Ca++ release of OC cells to undergo cell death remains unclear. Here, we report that GA-induced phosphorylation of B-cell lymphoma 2 (BCL-2)-interacting killer (BIK) (threonine (Thr) 33/Serine (Ser) 35) and p53 (Ser 15 and Ser 392), Bcl-2-associated x protein (BAX)/BCL-2 antagonist killer 1 (BAK) oligomerization on the ER and mitochondria, rising of cytosolic Ca++ and ROS, cytochrome c (Cyt c) release from the mitochondria, Ψm loss, and apoptosis were suppressed in cells co-treated with a specific inhibitor of casein kinase II (CK II) (4,5,6,7-tetrabromobenzotriazole). Small interfering RNA (siRNA)-mediated suppression of BIK inhibited GA-induced oligomeric complex of BAX/BAK in the ER and mitochondria, increase of cytosolic Ca++ and ROS, and apoptosis, but did not attenuate the increase in the level of Ser 15-phosphated p53 induced by GA. Blockade of p53 expression by short hairpin RNA suppressed BAX/BAK oligomerization and ER Ca++–ROS-associated apoptosis induced by GA but did not affect GA-induced phospho-BIK (Thr 33/Ser 35) levels. Induction of mitochondrial Cyt c release and ROS generation, increased cytosolic Ca++ level, and apoptosis by GA was attenuated by expression of the BAX or BAK siRNA. Over-expression of BCL-2 (but not BCL-XL) inhibited formation of ER oligomeric BAX/BAK by GA. Our results demonstrated that activation of the CK II by GA is required for the BIK-mediated ROS-dependent apoptotic activity of ER-associated BAX/BAK.
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Affiliation(s)
- Meng-Liang Lin
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan
| | - Shih-Shun Chen
- Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan
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Guzman RE, Bungert-Plümke S, Franzen A, Fahlke C. Preferential association with ClC-3 permits sorting of ClC-4 into endosomal compartments. J Biol Chem 2017; 292:19055-19065. [PMID: 28972156 DOI: 10.1074/jbc.m117.801951] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/15/2017] [Indexed: 11/06/2022] Open
Abstract
ClC-4 is an intracellular Cl-/H+ exchanger that is highly expressed in the brain and whose dysfunction has been linked to intellectual disability and epilepsy. Here we studied the subcellular localization of human ClC-4 in heterologous expression systems. ClC-4 is retained in the endoplasmic reticulum (ER) upon overexpression in HEK293T cells. Co-expression with distinct ClC-3 splice variants targets ClC-4 to late endosome/lysosomes (ClC-3a and ClC-3b) or recycling endosome (ClC-3c). When expressed in cultured astrocytes, ClC-4 sorted to endocytic compartments in WT cells but was retained in the ER in Clcn3-/- cells. To understand the virtual absence of ER-localized ClC-4 in WT astrocytes, we performed association studies by high-resolution clear native gel electrophoresis. Although other CLC channels and transporters form stable dimers, ClC-4 was mostly observed as monomer, with ClC-3-ClC-4 heterodimers being more stable than ClC-4 homodimers. We conclude that unique oligomerization properties of ClC-4 permit regulated targeting of ClC-4 to various endosomal compartment systems via expression of different ClC-3 splice variants.
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Affiliation(s)
- Raul E Guzman
- From the Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52425 Jülich, Germany
| | | | | | - Christoph Fahlke
- From the Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52425 Jülich, Germany
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Anjum K, Shagufta BI, Abbas SQ, Patel S, Khan I, Shah SAA, Akhter N, Hassan SSU. Current status and future therapeutic perspectives of glioblastoma multiforme (GBM) therapy: A review. Biomed Pharmacother 2017; 92:681-689. [PMID: 28582760 DOI: 10.1016/j.biopha.2017.05.125] [Citation(s) in RCA: 161] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 05/19/2017] [Accepted: 05/25/2017] [Indexed: 12/16/2022] Open
Abstract
Glioblastoma multiforme (GBM) is the deadliest form of heterogeneous brain cancer. It affects an enormous number of patients every year and the survival is approximately 8 to 15 months. GBM has driven by complex signaling pathways and considered as a most challenging to treat. Standard treatment of GBM includes surgery, radiation therapy, chemotherapy and also the combined treatment. This review article described inter and intra- tumor heterogeneity of GMB. In addition, recent chemotherapeutic agents, with their mechanism of action have been defined. FDA-approved drugs also been focused over here and most importantly highlighting some natural and synthetic and novel anti- glioma agents, that are the main focus of researchers nowadays.
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Affiliation(s)
- Komal Anjum
- Ocean College, Zhejiang University, Hangzhou, 310058, China
| | - Bibi Ibtesam Shagufta
- Department of Zoology, Kohat University of Science and Technology (KUST), K.P.K 26000, Pakistan
| | - Syed Qamar Abbas
- Faculty of Pharmacy, Gomal University D.I.Khan, K.P.K 29050, Pakistan
| | - Seema Patel
- Bioinformatics and Medical Informatics Research Center, San Diego State University, San Diego-92182, USA
| | - Ishrat Khan
- Ocean College, Zhejiang University, Hangzhou, 310058, China
| | | | - Najeeb Akhter
- Ocean College, Zhejiang University, Hangzhou, 310058, China
| | - Syed Shams Ul Hassan
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China.
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D'Orsi B, Mateyka J, Prehn JHM. Control of mitochondrial physiology and cell death by the Bcl-2 family proteins Bax and Bok. Neurochem Int 2017; 109:162-170. [PMID: 28315370 DOI: 10.1016/j.neuint.2017.03.010] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/07/2017] [Accepted: 03/09/2017] [Indexed: 01/14/2023]
Abstract
Neuronal cell death is often triggered by events that involve intracellular increases in Ca2+. Under resting conditions, the intracellular Ca2+ concentration is tightly controlled by a number of extrusion and sequestering mechanisms involving the plasma membrane, mitochondria, and ER. These mechanisms act to prevent a disruption of neuronal ion homeostasis. As these processes require ATP, excessive Ca2+ overloading may cause energy depletion, mitochondrial dysfunction, and may eventually lead to Ca2+-dependent cell death. Excessive Ca2+ entry though glutamate receptors (excitotoxicity) has been implicated in several neurologic and chronic neurodegenerative diseases, including ischemic stroke, epilepsy, and Alzheimer's disease. Recent evidence has revealed that excitotoxic cell death is regulated by the B-cell lymphoma-2 (Bcl-2) family of proteins. Bcl-2 proteins, comprising of both pro-apoptotic and anti-apoptotic members, have been shown to not only mediate the intrinsic apoptosis pathway by controlling mitochondrial outer membrane (MOM) integrity, but to also control neuronal Ca2+ homeostasis and energetics. In this review, the role of Bcl-2 family proteins in the regulation of apoptosis, their expression in the central nervous system and how they control Ca2+-dependent neuronal injury are summarized. We review the current knowledge on Bcl-2 family proteins in the regulation of mitochondrial function and bioenergetics, including the fusion and fission machinery, and their role in Ca2+ homeostasis regulation at the mitochondria and ER. Specifically, we discuss how the 'pro-apoptotic' Bcl-2 family proteins, Bax and Bok, physiologically expressed in the nervous system, regulate such 'non-apoptotic/daytime' functions.
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Affiliation(s)
- Beatrice D'Orsi
- Department of Physiology & Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Julia Mateyka
- Department of Physiology & Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Jochen H M Prehn
- Department of Physiology & Medical Physics, Centre for the Study of Neurological Disorders, Royal College of Surgeons in Ireland, Dublin 2, Ireland.
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Xiong L, Tang Y, Liu Z, Dai J, Wang X. BCL-2 inhibition impairs mitochondrial function and targets oral tongue squamous cell carcinoma. SPRINGERPLUS 2016; 5:1626. [PMID: 27722045 PMCID: PMC5031576 DOI: 10.1186/s40064-016-3310-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 09/12/2016] [Indexed: 01/07/2023]
Abstract
Purpose To understand the role of Bcl-2 overexpression in oral tongue squamous cell carcinoma (OTSCC) patients and investigate the efficacy of targeting Bcl-2 in OTSCC. Methods The expression level of Bcl-2 on normal tongue cells and OTSCC cells were measured by real-time PCR and western blotting. The functional roles of Bcl-2 were examined by MTS, flow cytometry and xenograft cancer mouse model. Mechanism studies were performed by analyzing mitochondrial functions in a panel of OTSCC cell lines. Results Bcl-2 is up-regulated at mRNA and protein levels in a panel of OTSCC cell lines compared to normal tongue epithelial cells (NTEC). Importantly, overexpression of Bcl-2 confers resistance of OTSCC cells to chemotherapeutic drug cisplatin treatment. Overexpression of Bcl-2 in NTEC significantly increased cell growth. In contrast, inhibition of Bcl-2 by genetic and pharmacological approaches inhibits proliferation and induces apoptosis in OTSCC cells. Mechanistically, Bcl-2 inhibitor ABT-199 impairs mitochondrial functions as shown by the decreased levels of mitochondrial membrane potential, mitochondrial respiration and ATP, and the increased levels of ROS in OTSCC cells. In addition, ABT-199 inhibits proliferation and induces apoptosis and mitochondrial dysfunctions in NTEC cells, but to a less extent than in OTSCC cells. We further show that ABT-199 augments the effects of cisplatin in eliminating OTSCC cells in in vitro tongue cancer cellular system and in vivo tongue cancer xenograft mouse model. Conclusions Inhibition of Bcl-2 effectively targets OTSCC cells through inhibiting proliferation and inducing apoptosis. Inhibition of Bcl-2 also augments the inhibitory effects of cisplatin in vitro and in vivo. Electronic supplementary material The online version of this article (doi:10.1186/s40064-016-3310-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lei Xiong
- Department of Oral Medicine, The Second Clinical Medical College, Yangtze University, Jingzhou Central Hospital, Jingzhou, People's Republic of China
| | - Yi Tang
- Department of Oral Medicine, The Second Clinical Medical College, Yangtze University, Jingzhou Central Hospital, Jingzhou, People's Republic of China
| | - Zhaoyang Liu
- Department of Oral Medicine, The Second Clinical Medical College, Yangtze University, Jingzhou Central Hospital, Jingzhou, People's Republic of China
| | - Jing Dai
- Department of Oral Medicine, The Second Clinical Medical College, Yangtze University, Jingzhou Central Hospital, Jingzhou, People's Republic of China
| | - Xiaozhou Wang
- Department of Clinical Medicine, Hubei College of Chinese Medicine, Academy Road 87, Jingzhou, 434020 People's Republic of China
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Inhibition and conformational change of SERCA3b induced by Bcl-2. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1865:121-131. [PMID: 27639965 DOI: 10.1016/j.bbapap.2016.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 09/10/2016] [Accepted: 09/13/2016] [Indexed: 02/04/2023]
Abstract
An interaction of Bcl-2 with SERCA had been documented in vitro using the SERCA1a isoform isolated from rat skeletal muscle [Dremina, E. S., Sharov, V. S., Kumar, K., Azidi, A., Michaelis, E. K., Schöneich, C. (2004) Biochem. J. 383 (361-370)]. Here, we demonstrate the interaction of Bcl-2 with the SERCA3b isoform both in vitro and in cell culture. In vitro, the interaction of Bcl-2 with SERCA3b was studied using Bcl-2∆21, a truncated form of human Bcl-2, and microsomes isolated from SERCA3b-overexpressing HEK-293 cells. For these experiments, SERCA3b was quantified by a combination of amino acid analysis and Western blotting. We observed that Bcl-2∆21 both inactivates SERCA3b and co-immunoprecipitates with SERCA3b. The incubation with Bcl-2∆21 changes the distribution of SERCA3b during sucrose density gradient centrifugation, likely as the result of Bcl-2∆21-induced conformational change of SERCA3b. When SERCA3b-overexpressing HEK-293 cells were co-transfected with Bcl-2, Bcl-2-dependent SERCA3b inactivation was observed. In these cells, Bcl-2 interaction with SERCA3b was demonstrated by co-immunoprecipitation. Furthermore, overexpression of Bcl-2 reduced fluorescein isothiocyanate (FITC) labeling of SERCA3b. Together, our data provide evidence for the interaction of Bcl-2 with SERCA3b in vitro and in cell culture, and for Bcl-2-dependent conformational and functional changes of SERCA3b.
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ER functions of oncogenes and tumor suppressors: Modulators of intracellular Ca(2+) signaling. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1364-78. [PMID: 26772784 DOI: 10.1016/j.bbamcr.2016.01.002] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 01/04/2016] [Accepted: 01/05/2016] [Indexed: 12/20/2022]
Abstract
Intracellular Ca(2+) signals that arise from the endoplasmic reticulum (ER), the major intracellular Ca(2+)-storage organelle, impact several mitochondrial functions and dictate cell survival and cell death processes. Furthermore, alterations in Ca(2+) signaling in cancer cells promote survival and establish a high tolerance towards cell stress and damage, so that the on-going oncogenic stress does not result in the activation of cell death. Over the last years, the mechanisms underlying these oncogenic alterations in Ca(2+) signaling have started to emerge. An important aspect of this is the identification of several major oncogenes, including Bcl-2, Bcl-XL, Mcl-1, PKB/Akt, and Ras, and tumor suppressors, such as p53, PTEN, PML, BRCA1, and Beclin 1, as direct and critical regulators of Ca(2+)-transport systems located at the ER membranes, including IP3 receptors and SERCA Ca(2+) pumps. In this way, these proteins execute part of their function by controlling the ER-mitochondrial Ca(2+) fluxes, favoring either survival (oncogenes) or cell death (tumor suppressors). Oncogenic mutations, gene deletions or amplifications alter the expression and/or function of these proteins, thereby changing the delicate balance between oncogenes and tumor suppressors, impacting oncogenesis and favoring malignant cell function and behavior. In this review, we provided an integrated overview of the impact of the major oncogenes and tumor suppressors, often altered in cancer cells, on Ca(2+) signaling from the ER Ca(2+) stores. This article is part of a Special Issue entitled: Calcium and Cell Fate. Guest Editors: Jacques Haiech, Claus Heizmann, Joachim Krebs, Thierry Capiod and Olivier Mignen.
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A conserved MADS-box phosphorylation motif regulates differentiation and mitochondrial function in skeletal, cardiac, and smooth muscle cells. Cell Death Dis 2015; 6:e1944. [PMID: 26512955 PMCID: PMC5399178 DOI: 10.1038/cddis.2015.306] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 09/07/2015] [Accepted: 09/14/2015] [Indexed: 12/19/2022]
Abstract
Exposure to metabolic disease during fetal development alters cellular differentiation and perturbs metabolic homeostasis, but the underlying molecular regulators of this phenomenon in muscle cells are not completely understood. To address this, we undertook a computational approach to identify cooperating partners of the myocyte enhancer factor-2 (MEF2) family of transcription factors, known regulators of muscle differentiation and metabolic function. We demonstrate that MEF2 and the serum response factor (SRF) collaboratively regulate the expression of numerous muscle-specific genes, including microRNA-133a (miR-133a). Using tandem mass spectrometry techniques, we identify a conserved phosphorylation motif within the MEF2 and SRF Mcm1 Agamous Deficiens SRF (MADS)-box that regulates miR-133a expression and mitochondrial function in response to a lipotoxic signal. Furthermore, reconstitution of MEF2 function by expression of a neutralizing mutation in this identified phosphorylation motif restores miR-133a expression and mitochondrial membrane potential during lipotoxicity. Mechanistically, we demonstrate that miR-133a regulates mitochondrial function through translational inhibition of a mitophagy and cell death modulating protein, called Nix. Finally, we show that rodents exposed to gestational diabetes during fetal development display muscle diacylglycerol accumulation, concurrent with insulin resistance, reduced miR-133a, and elevated Nix expression, as young adult rats. Given the diverse roles of miR-133a and Nix in regulating mitochondrial function, and proliferation in certain cancers, dysregulation of this genetic pathway may have broad implications involving insulin resistance, cardiovascular disease, and cancer biology.
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Harmse L, Dahan-Farkas N, Panayides JL, van Otterlo W, Penny C. Aberrant Apoptotic Response of Colorectal Cancer Cells to Novel Nucleoside Analogues. PLoS One 2015; 10:e0138607. [PMID: 26390405 PMCID: PMC4577089 DOI: 10.1371/journal.pone.0138607] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 09/01/2015] [Indexed: 12/19/2022] Open
Abstract
Despite the increased understanding of colorectal cancer and the introduction of targeted drug therapy, the metastatic phase of the disease remains refractory to treatment. Since the deregulation of normal apoptosis contributes to the pathogenesis of colorectal cancer, novel nucleoside analogues were synthesized here and evaluated for their ability to induce apoptosis and cause cell death in two colorectal adeno-carcinoma cell lines, Caco-2 and HT-29. Three novel nucleoside analogues assessed here showed cytotoxic activity, as measured by the MTT assay against both cell lines: the IC50 values ranged between 3 and 37 μM, with Caco-2 cells being more sensitive than HT-29 cells. Compared to camptothecin, the positive control, the nucleoside analogues were significantly less toxic to normal unstimulated leukocytes (p>0.05). Moreover, the nucleosides were able to induce apoptosis as measured by an increase in caspase 8 and caspase 3 activity above that of the control. This was additionally supported by data derived from Annexin V-FITC assays. Despite marginal changes to the mitochondrial membrane potential, all three nucleosides caused a significant increase in cytosolic cytochrome c (p>0.05), with a corresponding decrease in mitochondrial cytochrome c. Morphological analysis of both cell lines showed the rapid appearance of vacuoles following exposure to two of the nucleosides, while a third caused cellular detachment, delayed cytoplasmic vacuolisation and nuclear abnormalities. Preliminary investigations, using the autophagic indicator monodansylcadaverine and chloroquine as positive control, showed that two of the nucleosides induced the formation of autophagic vacuoles. In summary, the novel nucleoside analogues showed selective cytotoxicity towards both cancer cell lines and are effective initiators of an unusual apoptotic response, demonstrating their potential to serve as structural scaffolds for more potent analogues.
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Affiliation(s)
- Leonie Harmse
- Division of Pharmacology, Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, South Africa
- * E-mail:
| | - Nurit Dahan-Farkas
- Division of Pharmacology, Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, 2193, South Africa
| | - Jenny-Lee Panayides
- Molecular Sciences Institute, School of Chemistry, Faculty of Science, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa
| | - Willem van Otterlo
- Molecular Sciences Institute, School of Chemistry, Faculty of Science, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa
- Department of Chemistry and Polymer Sciences, Stellenbosch University, Private Bag XI, Matieland 7602, South Africa
| | - Clement Penny
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown 2193, South Africa
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Abstract
Excessive Ca(2+) entry during glutamate receptor overactivation ("excitotoxicity") induces acute or delayed neuronal death. We report here that deficiency in bax exerted broad neuroprotection against excitotoxic injury and oxygen/glucose deprivation in mouse neocortical neuron cultures and reduced infarct size, necrotic injury, and cerebral edema formation after middle cerebral artery occlusion in mice. Neuronal Ca(2+) and mitochondrial membrane potential (Δψm) analysis during excitotoxic injury revealed that bax-deficient neurons showed significantly reduced Ca(2+) transients during the NMDA excitation period and did not exhibit the deregulation of Δψm that was observed in their wild-type (WT) counterparts. Reintroduction of bax or a bax mutant incapable of proapoptotic oligomerization equally restored neuronal Ca(2+) dynamics during NMDA excitation, suggesting that Bax controlled Ca(2+) signaling independently of its role in apoptosis execution. Quantitative confocal imaging of intracellular ATP or mitochondrial Ca(2+) levels using FRET-based sensors indicated that the effects of bax deficiency on Ca(2+) handling were not due to enhanced cellular bioenergetics or increased Ca(2+) uptake into mitochondria. We also observed that mitochondria isolated from WT or bax-deficient cells similarly underwent Ca(2+)-induced permeability transition. However, when Ca(2+) uptake into the sarco/endoplasmic reticulum was blocked with the Ca(2+)-ATPase inhibitor thapsigargin, bax-deficient neurons showed strongly elevated cytosolic Ca(2+) levels during NMDA excitation, suggesting that the ability of Bax to support dynamic ER Ca(2+) handling is critical for cell death signaling during periods of neuronal overexcitation.
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41
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Chen F, Wu R, Zhu Z, Yin W, Xiong M, Sun J, Ni M, Cai G, Zhang X. Wogonin protects rat dorsal root ganglion neurons against tunicamycin-induced ER stress through the PERK-eIF2α-ATF4 signaling pathway. J Mol Neurosci 2014; 55:995-1005. [PMID: 25417142 DOI: 10.1007/s12031-014-0456-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 10/08/2014] [Indexed: 02/07/2023]
Abstract
Endoplasmic reticulum (ER) stress has been demonstrated to contribute to neurodegeneration in multiple nervous system diseases. Wogonin is a flavonoid isolated from Scutellaria baicalensis root and has multiple pharmacological effects, including anti-inflammatory, antioxidant, and anticancer effects. It has a protective role in nervous system diseases; however, the pharmacological function of wogonin in the spinal cord is still with limited acquaintance. In the present study, rat dorsal root ganglion (DRG) neurons were pretreated with different concentrations of wogonin (0-100 μM) before inducing ER stress using tunicamycin (TUN) (0.75 μg/ml). Wogonin pretreatment at 75 and 100 μM had a cytoprotective effect on cells against TUN-induced toxicity. Wogonin also decreased the number of the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive DRG neurons and increased expression of superoxide dismutase (SOD), which was accompanied by decreased malondialdehyde (MDA) level. The induction of apoptosis was prevented with reduction in expression level of Bax and concomitant increase in B cell lymphoma 2 (Bcl-2) level. Furthermore, wogonin downregulated expression level of ER stress genes coding for glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), active caspase 12, transcription factor 4 (ATF4), and phosphorylation of pancreatic ER stress kinase (PERK) and eukaryotic initiation factor 2 alpha (eIF2α). The current study indicated that wogonin modulated stress-responsive genes, helping DRG neurons prevent TUN-induced ER stress through the PERK-eIF2α-ATF4 signaling pathway.
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Affiliation(s)
- Fangyi Chen
- Department of Orthopedics, Affiliated Jinshan Hospital, Fudan University, Shanghai, 201508, People's Republic of China
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42
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Su YC, Guo X, Qi X. Threonine 56 phosphorylation of Bcl-2 is required for LRRK2 G2019S-induced mitochondrial depolarization and autophagy. Biochim Biophys Acta Mol Basis Dis 2014; 1852:12-21. [PMID: 25446991 DOI: 10.1016/j.bbadis.2014.11.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 11/05/2014] [Accepted: 11/10/2014] [Indexed: 12/18/2022]
Abstract
The G2019S leucine-rich repeat kinase 2 (LRRK2) mutation is the most common cause of genetic Parkinson's disease (PD). However, the molecular mechanism underlying LRRK2 G2019S-induced cellular pathology is poorly understood. Here, we demonstrated that LRRK2 G2019S bound to and phosphorylated Bcl-2, a mitochondrial anti-apoptotic protein, at Threonine 56. Either stable expression of Bcl-2 or transient expression of a Bcl-2 phosphor mutant (Bcl-2(T56A)) abolished LRRK2 G2019S-induced mitochondrial depolarization and autophagy. Together, our findings reveal a previously unidentified target of LRRK2 G2019S, showing that Bcl-2 serves as a point of crosstalk between LRRK2 G2019S-mediated mitochondrial disorder and dysregulation of autophagy.
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Affiliation(s)
- Yu-Chin Su
- Department of Physiology and Biophysics Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Xing Guo
- Department of Physiology and Biophysics Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Xin Qi
- Department of Physiology and Biophysics Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.,Center for Mitochondrial Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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43
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Bcl-2 family in inter-organelle modulation of calcium signaling; roles in bioenergetics and cell survival. J Bioenerg Biomembr 2014; 46:1-15. [PMID: 24078116 DOI: 10.1007/s10863-013-9527-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 08/27/2013] [Indexed: 01/01/2023]
Abstract
Bcl-2 family proteins, known for their apoptosis functioning at the mitochondria, have been shown to localize to other cellular compartments to mediate calcium (Ca2+) signals. Since the proper supply of Ca2+ in cells serves as an important mechanism for cellular survival and bioenergetics, we propose an integrating role for Bcl-2 family proteins in modulating Ca2+ signaling. The endoplasmic reticulum (ER) is the main Ca2+ storage for the cell and Bcl-2 family proteins competitively regulate its Ca2+ concentration. Bcl-2 family proteins also regulate the flux of Ca2+ from the ER by physically interacting with inositol 1,4,5-trisphosphate receptors (IP3Rs) to mediate their opening. Type 1 IP3Rs reside at the bulk ER to coordinate cytosolic Ca2+ signals, while type 3 IP3Rs reside at mitochondria-associated ER membrane (MAM) to facilitate mitochondrial Ca2+ uptake. In healthy cells, mitochondrial Ca2+ drives pyruvate into the citric acid (TCA) cycle to facilitate ATP production, while a continuous accumulation of Ca2+ can trigger the release of cytochrome c, thus initiating apoptosis. Since multiple organelles and Bcl-2 family proteins are involved in Ca2+ signaling, we aim to clarify the role that Bcl-2 family proteins play in facilitating Ca2+ signaling and how mitochondrial Ca2+ is relevant in both bioenergetics and apoptosis. We also explore how these insights could be useful in controlling bioenergetics in apoptosis-resistant cell lines.
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44
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Suppression of PI3K/Akt signaling by synthetic bichalcone analog TSWU-CD4 induces ER stress- and Bax/Bak-mediated apoptosis of cancer cells. Apoptosis 2014; 19:1637-53. [DOI: 10.1007/s10495-014-1031-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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45
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Kleemann B, Loos B, Scriba TJ, Lang D, Davids LM. St John's Wort (Hypericum perforatum L.) photomedicine: hypericin-photodynamic therapy induces metastatic melanoma cell death. PLoS One 2014; 9:e103762. [PMID: 25076130 PMCID: PMC4116257 DOI: 10.1371/journal.pone.0103762] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 07/01/2014] [Indexed: 12/24/2022] Open
Abstract
Hypericin, an extract from St John's Wort (Hypericum perforatum L.), is a promising photosensitizer in the context of clinical photodynamic therapy due to its excellent photosensitizing properties and tumoritropic characteristics. Hypericin-PDT induced cytotoxicity elicits tumor cell death by various mechanisms including apoptosis, necrosis and autophagy-related cell death. However, limited reports on the efficacy of this photomedicine for the treatment of melanoma have been published. Melanoma is a highly aggressive tumor due to its metastasizing potential and resistance to conventional cancer therapies. The aim of this study was to investigate the response mechanisms of melanoma cells to hypericin-PDT in an in vitro tissue culture model. Hypericin was taken up by all melanoma cells and partially co-localized to the endoplasmic reticulum, mitochondria, lysosomes and melanosomes, but not the nucleus. Light activation of hypericin induced a rapid, extensive modification of the tubular mitochondrial network into a beaded appearance, loss of structural details of the endoplasmic reticulum and concomitant loss of hypericin co-localization. Surprisingly the opposite was found for lysosomal-related organelles, suggesting that the melanoma cells may be using these intracellular organelles for hypericin-PDT resistance. In line with this speculation we found an increase in cellular granularity, suggesting an increase in pigmentation levels in response to hypericin-PDT. Pigmentation in melanoma is related to a melanocyte-specific organelle, the melanosome, which has recently been implicated in drug trapping, chemotherapy and hypericin-PDT resistance. However, hypericin-PDT was effective in killing both unpigmented (A375 and 501mel) and pigmented (UCT Mel-1) melanoma cells by specific mechanisms involving the externalization of phosphatidylserines, cell shrinkage and loss of cell membrane integrity. In addition, this treatment resulted in extrinsic (A375) and intrinsic (UCT Mel-1) caspase-dependent apoptotic modes of cell death, as well as a caspase-independent apoptotic mode that did not involve apoptosis-inducing factor (501 mel). Further research is needed to shed more light on these mechanisms.
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Affiliation(s)
- Britta Kleemann
- Redox Laboratory and Confocal and Light Microscope Imaging Facility, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Benjamin Loos
- Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Thomas J. Scriba
- South African TB Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine and School of Child and Adolescent Health, University of Cape Town, Cape Town, South Africa
| | - Dirk Lang
- Redox Laboratory and Confocal and Light Microscope Imaging Facility, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Lester M. Davids
- Redox Laboratory and Confocal and Light Microscope Imaging Facility, Department of Human Biology, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- * E-mail:
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46
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Pan Z, Avila A, Gollahon L. Paclitaxel induces apoptosis in breast cancer cells through different calcium--regulating mechanisms depending on external calcium conditions. Int J Mol Sci 2014; 15:2672-94. [PMID: 24549172 PMCID: PMC3958875 DOI: 10.3390/ijms15022672] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 02/10/2014] [Accepted: 02/11/2014] [Indexed: 12/19/2022] Open
Abstract
Previously, we reported that endoplasmic reticulum calcium stores were a direct target for paclitaxel initiation of apoptosis. Furthermore, the actions of paclitaxel attenuated Bcl-2 resistance to apoptosis through endoplasmic reticulum-mediated calcium release. To better understand the calcium-regulated mechanisms of paclitaxel-induced apoptosis in breast cancer cells, we investigated the role of extracellular calcium, specifically; whether influx of extracellular calcium contributed to and/or was necessary for paclitaxel-induced apoptosis. Our results demonstrated that paclitaxel induced extracellular calcium influx. This mobilization of extracellular calcium contributed to subsequent cytosolic calcium elevation differently, depending on dosage. Under normal extracellular calcium conditions, high dose paclitaxel induced apoptosis-promoting calcium influx, which did not occur in calcium-free conditions. In the absence of extracellular calcium an “Enhanced Calcium Efflux” mechanism in which high dose paclitaxel stimulated calcium efflux immediately, leading to dramatic cytosolic calcium decrease, was observed. In the absence of extracellular calcium, high dose paclitaxel’s stimulatory effects on capacitative calcium entry and apoptosis could not be completely restored. Thus, normal extracellular calcium concentrations are critical for high dose paclitaxel-induced apoptosis. In contrast, low dose paclitaxel mirrored controls, indicating that it occurs independent of extracellular calcium. Thus, extracellular calcium conditions only affect efficacy of high dose paclitaxel-induced apoptosis.
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Affiliation(s)
- Zhi Pan
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
| | - Andrew Avila
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
| | - Lauren Gollahon
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
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47
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Wu LF, Guo YT, Zhang QH, Xiang MQ, Deng W, Ye YQ, Pu ZJ, Feng JL, Huang GY. Enhanced antitumor effects of adenoviral-mediated siRNA against GRP78 gene on adenosine-induced apoptosis in human hepatoma HepG2 cells. Int J Mol Sci 2014; 15:525-44. [PMID: 24394318 PMCID: PMC3907823 DOI: 10.3390/ijms15010525] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 12/19/2013] [Accepted: 12/23/2013] [Indexed: 02/05/2023] Open
Abstract
Our previous studies show that adenosine-induced apoptosis is involved in endoplasmic reticulum stress in HepG2 cells. In this study, we have investigated whether knockdown of GRP78 by short hairpin RNA (shRNA) increases the cytotoxic effects of adenosine in HepG2 cells. The adenovirus vector-delivered shRNA targeting GRP78 (Ad-shGRP78) was constructed and transfected into HepG2 cells. RT-PCR assay was used to determine RNA interference efficiency. Effects of knockdown of GRP78 on adenosine-induced cell viabilities, cell-cycle distribution and apoptosis, as well as relative protein expressions were determined by flow cytometry and/or Western blot analysis. The intracellular Ca2+ concentration was detected by laser scanning confocal microscope. Mitochondrial membrane potential (ΔΨm) was measured by a fluorospectrophotometer. The results revealed that GRP78 mRNA was significantly downregulated by Ad-shGRP78 transfection. Knockdown of GRP78 enhanced HepG2 cell sensitivity to adenosine by modulating G0/G1 arrest and stimulating Bax, Bak, m-calpain, caspase-4 and CHOP protein levels. Knockdown of GRP78 worsened cytosolic Ca2+ overload and ΔΨm loss. Knockdown of caspase-4 by shRNA decreased caspase-3 mRNA expression and cell apoptosis. These findings indicate that GRP 78 plays a protective role in ER stress-induced apoptosis and show that the combination of chemotherapy drug and RNA interference adenoviruses provides a new treatment strategy against malignant tumors.
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Affiliation(s)
- Ling-Fei Wu
- Department of Gastroenterology and Information, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China.
| | - Yi-Tian Guo
- Department of Gastroenterology and Information, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China.
| | - Qing-Hua Zhang
- Department of Gastroenterology and Information, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China.
| | - Meng-Qi Xiang
- Department of Gastroenterology and Information, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China.
| | - Wei Deng
- Department of Gastroenterology and Information, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China.
| | - Yan-Qing Ye
- Department of Gastroenterology and Information, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China.
| | - Ze-Jin Pu
- Department of Gastroenterology and Information, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China.
| | - Jia-Lin Feng
- Department of Gastroenterology and Information, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China.
| | - Guan-You Huang
- Department of Gastroenterology and Information, Second Affiliated Hospital, Shantou University Medical College, Shantou 515041, China.
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48
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Cao Y, Li X, Shi P, Wang LX, Sui ZG. Effects of L-Carnitine on High Glucose-Induced Oxidative Stress in Retinal Ganglion Cells. Pharmacology 2014; 94:123-30. [DOI: 10.1159/000363062] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 04/22/2014] [Indexed: 11/19/2022]
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49
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ERO1α-dependent endoplasmic reticulum-mitochondrial calcium flux contributes to ER stress and mitochondrial permeabilization by procaspase-activating compound-1 (PAC-1). Cell Death Dis 2013; 4:e968. [PMID: 24357799 PMCID: PMC3877569 DOI: 10.1038/cddis.2013.502] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 10/10/2013] [Indexed: 12/18/2022]
Abstract
Procaspase-activating compound-1 (PAC-1) is the first direct caspase-activating compound discovered; using an in vitro cell-free system of caspase activation. Subsequently, this compound was shown to induce apoptosis in a variety of cancer cells with promising in vivo antitumor activity in canine lymphoma model. Recently, we have reported its ability to kill drug-resistant, Bcl-2/Bcl-xL overexpressing and Bax/Bak-deficient cells despite the essential requirement of mitochondrial cytochrome c (cyt. c) release for caspase activation, indicating that the key molecular targets of PAC-1 in cancer cells are yet to be identified. Here, we have identified Ero1α-dependent endoplasmic reticulum (ER) calcium leakage to mitochondria through mitochondria-associated ER membranes (MAM) and ER luminal hyper-oxidation as the critical events of PAC-1-mediated cell death. PAC-1 treatment upregulated Ero1α in multiple cell lines, whereas silencing of Ero1α significantly inhibited calcium release from ER and cell death. Loss of ER calcium and hyper-oxidation of ER lumen by Ero1α collectively triggered ER stress. Upregulation of GRP78 and splicing of X-box-binding protein 1 (XBP1) mRNA in multiple cancer cells suggested ER stress as the general event triggered by PAC-1. XBP1 mRNA splicing and GRP78 upregulation confirmed ER stress even in Bax/Bak double knockout and PAC-1-resistant Apaf-1-knockout cells, indicating an induction of ER stress-mediated mitochondrial apoptosis by PAC-1. Furthermore, we identified BH3-only protein p53 upregulated modulator of apoptosis (PUMA) as the key molecular link that orchestrates overwhelmed ER stress to mitochondria-mediated apoptosis, involving mitochondrial reactive oxygen species, in a p53-independent manner. Silencing of PUMA in cancer cells effectively reduced cyt. c release and cell death by PAC-1.
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50
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Ma P, Schwarten M, Schneider L, Boeske A, Henke N, Lisak D, Weber S, Mohrlüder J, Stoldt M, Strodel B, Methner A, Hoffmann S, Weiergräber OH, Willbold D. Interaction of Bcl-2 with the autophagy-related GABAA receptor-associated protein (GABARAP): biophysical characterization and functional implications. J Biol Chem 2013; 288:37204-15. [PMID: 24240096 DOI: 10.1074/jbc.m113.528067] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Apoptosis and autophagy are fundamental homeostatic processes in eukaryotic organisms fulfilling essential roles in development and adaptation. Recently, the anti-apoptotic factor Bcl-2 has been reported to also inhibit autophagy, thus establishing a potential link between these pathways, but the mechanistic details are only beginning to emerge. Here we show that Bcl-2 directly binds to the phagophore-associated protein GABARAP. NMR experiments revealed that the interaction critically depends on a three-residue segment (EWD) of Bcl-2 adjacent to the BH4 region, which is anchored to one of the two hydrophobic pockets on the GABARAP molecule. This is at variance with the majority of GABARAP interaction partners identified previously, which occupy both hydrophobic pockets simultaneously. Bcl-2 affinity could also be detected for GEC1, but not for other mammalian Atg8 homologs. Finally, we provide evidence that overexpression of Bcl-2 inhibits lipidation of GABARAP, a key step in autophagosome formation, possibly via competition with the lipid conjugation machinery. These results support the regulatory role of Bcl-2 in autophagy and define GABARAP as a novel interaction partner involved in this intricate connection.
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Affiliation(s)
- Peixiang Ma
- From the Institute of Complex Systems (ICS-6: Structural Biochemistry), Forschungszentrum Jülich, 52425 Jülich and
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