151
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Kovacs GG, Adle-Biassette H, Milenkovic I, Cipriani S, van Scheppingen J, Aronica E. Linking pathways in the developing and aging brain with neurodegeneration. Neuroscience 2014; 269:152-72. [PMID: 24699227 DOI: 10.1016/j.neuroscience.2014.03.045] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 03/21/2014] [Accepted: 03/21/2014] [Indexed: 12/12/2022]
Abstract
The molecular and cellular mechanisms, which coordinate the critical stages of brain development to reach a normal structural organization with appropriate networks, are progressively being elucidated. Experimental and clinical studies provide evidence of the occurrence of developmental alterations induced by genetic or environmental factors leading to the formation of aberrant networks associated with learning disabilities. Moreover, evidence is accumulating that suggests that also late-onset neurological disorders, even Alzheimer's disease, might be considered disorders of aberrant neural development with pathological changes that are set up at early stages of development before the appearance of the symptoms. Thus, evaluating proteins and pathways that are important in age-related neurodegeneration in the developing brain together with the characterization of mechanisms important during brain development with relevance to brain aging are of crucial importance. In the present review we focus on (1) aspects of neurogenesis with relevance to aging; (2) neurodegenerative disease (NDD)-associated proteins/pathways in the developing brain; and (3) further pathways of the developing or neurodegenerating brains that show commonalities. Elucidation of complex pathogenetic routes characterizing the earliest stage of the detrimental processes that result in pathological aging represents an essential first step toward a therapeutic intervention which is able to reverse these pathological processes and prevent the onset of the disease. Based on the shared features between pathways, we conclude that prevention of NDDs of the elderly might begin during the fetal and childhood life by providing the mothers and their children a healthy environment for the fetal and childhood development.
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Affiliation(s)
- G G Kovacs
- Institute of Neurology, Medical University of Vienna, Austria.
| | - H Adle-Biassette
- Inserm U1141, F-75019 Paris, France; Univ Paris Diderot, Sorbonne Paris Cité, UMRS 676, F-75019 Paris, France; Department of Pathology, Lariboisière Hospital, APHP, Paris, France
| | - I Milenkovic
- Institute of Neurology, Medical University of Vienna, Austria
| | | | - J van Scheppingen
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, The Netherlands
| | - E Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, The Netherlands; SEIN - Stichting Epilepsie Instellingen Nederland, Heemstede, The Netherlands; Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, The Netherlands
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152
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Heavey S, O’Byrne KJ, Gately K. Strategies for co-targeting the PI3K/AKT/mTOR pathway in NSCLC. Cancer Treat Rev 2014; 40:445-56. [DOI: 10.1016/j.ctrv.2013.08.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 08/11/2013] [Accepted: 08/16/2013] [Indexed: 12/20/2022]
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153
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Uzdensky AB, Rudkovskii MV, Fedorenko GM, Berezhnaya EV, Ischenko IA, Kovaleva VD, Komandirov MA, Neginskaya MA, Khaitin AM, Sharifulina SA. Responses of crayfish neurons and glial cells to photodynamic impact: Intracellular signaling, ultrastructural changes, and neuroglial interactions. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2014. [DOI: 10.1134/s1990747813050218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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154
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Li G, Liu L, Shan C, Cheng Q, Budhraja A, Zhou T, Cui H, Gao N. RhoA/ROCK/PTEN signaling is involved in AT-101-mediated apoptosis in human leukemia cells in vitro and in vivo. Cell Death Dis 2014; 5:e998. [PMID: 24434521 PMCID: PMC4040709 DOI: 10.1038/cddis.2013.519] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 11/11/2013] [Accepted: 11/25/2013] [Indexed: 12/22/2022]
Abstract
R-(-)-gossypol acetic acid (AT-101) is a natural cottonseed product that exhibits anticancer activity. However, the molecular mechanism behind the antileukemic activity of AT-101 has not been well characterized. In this study, we investigated how AT-101 induces apoptosis in human leukemia cells. Exposure to AT-101 significantly increased apoptosis in both human leukemia cell lines and primary human leukemia cells. This increase was accompanied by the activation of caspases, cytochrome c release, Bcl2-associated X protein (Bax) translocation, myeloid cell leukemia-1 (Mcl-1) downregulation, Bcl-2-associated death promoter (Bad) dephosphorylation, Akt inactivation, and RhoA/Rho-associated coiled-coil containing protein kinase 1/phosphatase and tensin homolog (RhoA/ROCK1/PTEN) activation. RhoA, rather than caspase-3 cleavage, mediated the cleavage/activation of ROCK1 that AT-101 induced. Inhibiting RhoA and ROCK1 activation by C3 exoenzyme (C3) and Y27632, respectively, attenuated the ROCK1 cleavage/activation, PTEN activity, Akt inactivation, Mcl-1 downregulation, Bad dephosphorylation, and apoptosis mediated by AT-101. Knocking down ROCK1 expression using a ROCK1-specific siRNA also significantly abrogated AT-101-mediated apoptosis. Constitutively active Akt prevented the AT-101-induced Mcl-1 downregulation, Bad dephosphorylation, and apoptosis. Conversely, AT-101 lethality was potentiated by the phosphatidylinositol 3-kinase inhibitor LY294002. In vivo, the tumor growth inhibition caused by AT-101 was also associated with RhoA/ROCK1/PTEN activation and Akt inactivation in a mouse leukemia xenograft model. Collectively, these findings suggest that AT-101 may preferentially induce apoptosis in leukemia cells by interrupting the RhoA/ROCK1/PTEN pathway, leading to Akt inactivation, Mcl-1 downregulation, Bad dephosphorylation, and Bax translocation, which culminate in mitochondrial injury and apoptosis.
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Affiliation(s)
- G Li
- Department of Pharmacognosy, College of Pharmacy, Third Military Medical University, Chongqing, China
| | - L Liu
- Department of Pharmacognosy, College of Pharmacy, Third Military Medical University, Chongqing, China
| | - C Shan
- Department of Pharmacognosy, College of Pharmacy, Third Military Medical University, Chongqing, China
| | - Q Cheng
- Department of Pharmacognosy, College of Pharmacy, Third Military Medical University, Chongqing, China
| | - A Budhraja
- Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - T Zhou
- Department of Pharmacognosy, College of Pharmacy, Third Military Medical University, Chongqing, China
| | - H Cui
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - N Gao
- Department of Pharmacognosy, College of Pharmacy, Third Military Medical University, Chongqing, China
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155
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Son D, Na YR, Hwang ES, Seok SH. Platelet-derived growth factor-C (PDGF-C) induces anti-apoptotic effects on macrophages through Akt and Bad phosphorylation. J Biol Chem 2014; 289:6225-35. [PMID: 24421315 DOI: 10.1074/jbc.m113.508994] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PDGF-C, which is abundant in the malignant breast tumor microenvironment, plays an important role in cell growth and survival. Because tumor-associated macrophages (TAMs) contribute to cancer malignancy, macrophage survival mechanisms are an attractive area of research into controlling tumor progression. In this study, we investigated PDGF-C-mediated signaling pathways involved in anti-apoptotic effects in macrophages. We found that the human malignant breast cancer cell line MDA-MB-231 produced high quantities of PDGF-C, whereas benign MCF-7 cells did not. Recombinant PDGF-C induced PDGF receptor α chain phosphorylation, followed by Akt and Bad phosphorylation in THP-1-derived macrophages. MDA-MB-231 culture supernatants also activated macrophage PDGF-Rα. PDGF-C prevented staurosporine-induced macrophage apoptosis by inhibiting the activation of caspase-3, -7, -8, and -9 and cleavage of poly(ADP-ribose) polymerase. Finally, TAMs isolated from the PDGF-C knockdown murine breast cancer cell line 4T1 and PDGF-C knockdown MDA-MB-231-derived tumor mass showed higher rates of apoptosis than the respective WT controls. Collectively, our results suggest that tumor cell-derived PDGF-C enhances TAM survival, promoting tumor malignancy.
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Affiliation(s)
- Dain Son
- From the Department of Microbiology and Immunology, and Institute of Endemic Disease, College of Medicine, Seoul National University, Seoul 110-799, Korea
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156
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Takahashi A, Ma H, Nakagawa A, Yoshida Y, Kanai T, Ohno T, Kuwahara Y, Fukumoto M, Nakano T. Carbon-Ion Beams Efficiently Induce Cell Killing in X-Ray Resistant Human Squamous Tongue Cancer Cells. ACTA ACUST UNITED AC 2014. [DOI: 10.4236/ijmpcero.2014.33019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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157
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PI3K. Mol Oncol 2013. [DOI: 10.1017/cbo9781139046947.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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158
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Diehl N, Schaal H. Make yourself at home: viral hijacking of the PI3K/Akt signaling pathway. Viruses 2013; 5:3192-212. [PMID: 24351799 PMCID: PMC3967167 DOI: 10.3390/v5123192] [Citation(s) in RCA: 149] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/03/2013] [Accepted: 12/05/2013] [Indexed: 01/04/2023] Open
Abstract
As viruses do not possess genes encoding for proteins required for translation, energy metabolism or membrane biosynthesis, they are classified as obligatory intracellular parasites that depend on a host cell to replicate. This genome limitation forces them to gain control over cellular processes to ensure their successful propagation. A diverse spectrum of virally encoded proteins tackling a broad spectrum of cellular pathways during most steps of the viral life cycle ranging from the host cell entry to viral protein translation has evolved. Since the host cell PI3K/Akt signaling pathway plays a critical regulatory role in many cellular processes including RNA processing, translation, autophagy and apoptosis, many viruses, in widely varying ways, target it. This review focuses on a number of remarkable examples of viral strategies, which exploit the PI3K/Akt signaling pathway for effective viral replication.
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Affiliation(s)
| | - Heiner Schaal
- Universitätsklinikum Düsseldorf, Institut für Virologie, Universitätsstraße 1, Düsseldorf 40225, Germany.
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159
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Hsu YH, Chen TH, Chen YC, Cheng CY, Sue YM, Chen JR, Chen CH. Urotensin II exerts antiapoptotic effect on NRK-52E cells through prostacyclin-mediated peroxisome proliferator-activated receptor alpha and Akt activation. Mol Cell Endocrinol 2013; 381:168-74. [PMID: 23933501 DOI: 10.1016/j.mce.2013.07.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 07/11/2013] [Accepted: 07/28/2013] [Indexed: 12/21/2022]
Abstract
Urotensin II (UII) is a cyclic vasoactive peptide which is mainly expressed in kidneys. Although elevated plasma UII levels are associated with renal impairment, the influence of UII on renal injury is unclear. In this study, we monitored the influence of UII on gentamicin-induced apoptosis in rat tubular cells (NRK-52E). We found that UII significantly reduced gentamicin-induced apoptosis and apoptotic signals. Blocking endogenous UII secretion caused cells to be more susceptible to gentamicin. In gentamicin-treated mice, UII also expressed protective effect on renal tubular cells. UII was also found to induce prostacyclin (PGI2) production, which caused peroxisomal proliferator-activated receptor α (PPARα) activation as revealed by both PGI2 synthase siRNA transfection and piroxicam treatment. Blockage of PPARα by siRNA transfection inhibited UII-induced Akt phosphorylation and the antiapoptotic effect of UII. Our results suggest that UII can protect renal tubular cells from gentamicin-induced apoptosis through PGI2-mediated PPARα and Akt activation.
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Affiliation(s)
- Yung-Ho Hsu
- Division of Nephrology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
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160
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Akinleye A, Avvaru P, Furqan M, Song Y, Liu D. Phosphatidylinositol 3-kinase (PI3K) inhibitors as cancer therapeutics. J Hematol Oncol 2013; 6:88. [PMID: 24261963 PMCID: PMC3843585 DOI: 10.1186/1756-8722-6-88] [Citation(s) in RCA: 192] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 11/12/2013] [Indexed: 02/08/2023] Open
Abstract
Phosphatidylinositol 3-kinases (PI3Ks) are lipid kinases that regulate diverse cellular processes including proliferation, adhesion, survival, and motility. Dysregulated PI3K pathway signaling occurs in one-third of human tumors. Aberrantly activated PI3K signaling also confers sensitivity and resistance to conventional therapies. PI3K has been recognized as an attractive molecular target for novel anti-cancer molecules. In the last few years, several classes of potent and selective small molecule PI3K inhibitors have been developed, and at least fifteen compounds have progressed into clinical trials as new anticancer drugs. Among these, idelalisib has advanced to phase III trials in patients with advanced indolent non-Hodgkin's lymphoma and mantle cell lymphoma. In this review, we summarized the major molecules of PI3K signaling pathway, and discussed the preclinical models and clinical trials of potent small-molecule PI3K inhibitors.
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Affiliation(s)
| | | | | | | | - Delong Liu
- Division of Hematology/Oncology, Department of Medicine, New York Medical College and Westchester Medical Center, Valhalla, NY 10595, USA.
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161
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Yang C, Fan J, Zhuang Z, Fang Y, Zhang Y, Wang S. The role of NAD(+)-dependent isocitrate dehydrogenase 3 subunit α in AFB1 induced liver lesion. Toxicol Lett 2013; 224:371-9. [PMID: 24211421 DOI: 10.1016/j.toxlet.2013.10.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 10/25/2013] [Accepted: 10/28/2013] [Indexed: 01/24/2023]
Abstract
Aflatoxin B1 (AFB1) is a potent hepatocarcinogen that causes carcinogenesis in many animal species. In previous study, we found that isocitrate dehydrogenase 3α subunit (IDH3α) was upregulated in AFB1-induced carcinogenesis process. In this study, the sequences of IDH3α from various species were compared and the protein expression levels in different organs were examined, and the results showed that IDH3α was a widely distributed protein and shared highly conserved sequence in various species. In the same time, IDH3α was demonstrated to accumulate in a dose-dependent manner induced by AFB1 in cells, and was also up-regulated in the process of AFB1-induced liver lesion. Similar results were observed when H2O2 was used to replace AFB1. Over-expression of IDH3α increased the phosphorylation level of Akt (Protein kinase B) and neutralized the cellular toxicity induced by AFB1 or H2O2 and apoptosis induced by AFB1, while the reduced expression of IDH3α by siRNA decreased the phosphorylation, indicating that IDH3α played important roles in oxidative stress-induced PI3K/Akt pathway. Overall, the results suggested that AFB1 treatment could increase the expression of IDH3α, and the activated PI3K/Akt pathway by IDH3α eventually neutralized the apoptosis induced by AFB1.
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Affiliation(s)
- Chi Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, The Ministry of Education Key Laboratory of Biopesticide and Chemical Biology, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jue Fan
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, The Ministry of Education Key Laboratory of Biopesticide and Chemical Biology, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhenhong Zhuang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, The Ministry of Education Key Laboratory of Biopesticide and Chemical Biology, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yi Fang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, The Ministry of Education Key Laboratory of Biopesticide and Chemical Biology, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yanfeng Zhang
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, The Ministry of Education Key Laboratory of Biopesticide and Chemical Biology, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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162
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Fuchs CS, Ogino S. Aspirin therapy for colorectal cancer with PIK3CA mutation: simply complex! J Clin Oncol 2013; 31:4358-61. [PMID: 24166520 DOI: 10.1200/jco.2013.52.0080] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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163
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Abstract
Hsp90 is a major molecular chaperone that is expressed abundantly and plays a pivotal role in assisting correct folding and functionality of its client proteins in cells. The Hsp90 client proteins include a wide variety of signal transducing molecules such as protein kinases and steroid hormone receptors. Cancer is a complex disease, but most types of human cancer share common hallmarks, including self-sufficiency in growth signals, insensitivity to growth-inhibitory mechanism, evasion of programmed cell death, limitless replicative potential, sustained angiogenesis, and tissue invasion and metastasis. A surprisingly large number of Hsp90-client proteins play crucial roles in establishing cancer cell hallmarks. We start the review by describing the structure and function of Hsp90 since conformational changes during the ATPase cycle of Hsp90 are closely related to its function. Many co-chaperones, including Hop, p23, Cdc37, Aha1, and PP5, work together with Hsp90 by modulating the chaperone machinery. Post-translational modifications of Hsp90 and its cochaperones are vital for their function. Many tumor-related Hsp90-client proteins, including signaling kinases, steroid hormone receptors, p53, and telomerase, are described. Hsp90 and its co-chaperones are required for the function of these tumor-promoting client proteins; therefore, inhibition of Hsp90 by specific inhibitors such as geldanamycin and its derivatives attenuates the tumor progression. Hsp90 inhibitors can be potential and effective cancer chemotherapeutic drugs with a unique profile and have been examined in clinical trials. We describe possible mechanisms why Hsp90 inhibitors show selectivity to cancer cells even though Hsp90 is essential also for normal cells. Finally, we discuss the "Hsp90-addiction" of cancer cells, and suggest a role for Hsp90 in tumor evolution.
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Affiliation(s)
- Yoshihiko Miyata
- Department of Cell & Developmental Biology, Graduate School of Biostudies, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
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164
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Miyata Y, Nakamoto H, Neckers L. The therapeutic target Hsp90 and cancer hallmarks. Curr Pharm Des 2013; 19:347-65. [PMID: 22920906 DOI: 10.2174/138161213804143725] [Citation(s) in RCA: 244] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 08/15/2012] [Indexed: 01/22/2023]
Abstract
Hsp90 is a major molecular chaperone that is expressed abundantly and plays a pivotal role in assisting correct folding and functionality of its client proteins in cells. The Hsp90 client proteins include a wide variety of signal transducing molecules such as protein kinases and steroid hormone receptors. Cancer is a complex disease, but most types of human cancer share common hallmarks, including self-sufficiency in growth signals, insensitivity to growth-inhibitory mechanism, evasion of programmed cell death, limitless replicative potential, sustained angiogenesis, and tissue invasion and metastasis. A surprisingly large number of Hsp90-client proteins play crucial roles in establishing cancer cell hallmarks. We start the review by describing the structure and function of Hsp90 since conformational changes during the ATPase cycle of Hsp90 are closely related to its function. Many co-chaperones, including Hop, p23, Cdc37, Aha1, and PP5, work together with Hsp90 by modulating the chaperone machinery. Post-translational modifications of Hsp90 and its cochaperones are vital for their function. Many tumor-related Hsp90-client proteins, including signaling kinases, steroid hormone receptors, p53, and telomerase, are described. Hsp90 and its co-chaperones are required for the function of these tumor-promoting client proteins; therefore, inhibition of Hsp90 by specific inhibitors such as geldanamycin and its derivatives attenuates the tumor progression. Hsp90 inhibitors can be potential and effective cancer chemotherapeutic drugs with a unique profile and have been examined in clinical trials. We describe possible mechanisms why Hsp90 inhibitors show selectivity to cancer cells even though Hsp90 is essential also for normal cells. Finally, we discuss the "Hsp90-addiction" of cancer cells, and suggest a role for Hsp90 in tumor evolution.
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Affiliation(s)
- Yoshihiko Miyata
- Department of Cell & Developmental Biology, Graduate School of Biostudies, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
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165
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Hwabejire JO, Lu J, Liu B, Li Y, Halaweish I, Alam HB. Valproic acid for the treatment of hemorrhagic shock: a dose-optimization study. J Surg Res 2013; 186:363-70. [PMID: 24135375 DOI: 10.1016/j.jss.2013.09.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 09/11/2013] [Accepted: 09/12/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND Valproic acid (VPA) has been shown to improve survival in animal models of hemorrhagic shock at a dose of 300 mg/kg. Our aim was to identify the ideal dose through dose-escalation, split-dosing, and dose de-escalation regimens. MATERIALS AND METHODS Rats were subjected to sublethal 40% hemorrhage and treated with vehicle or VPA (dose of 300, 400, or 450 mg/kg) after 30 min of shock. Acetylated histones and activated proteins from the PI3K-Akt-GSK-3β survival pathway at different time points were quantified by Western blot analysis. In a similar model, a VPA dose of 200 mg/kg followed 2 h later by another dose of 100 mg/kg was administered. Finally, animals were subjected to a lethal 50% hemorrhage and VPA was administered in a dose de-escalation manner (starting at dose of 300 mg/kg) until a significant drop in percent survival was observed. RESULTS Larger doses of VPA resulted in greater acetylation of histone 3 and increased activation of PI3K pathway proteins. Dose-dependent differences were significant in histone acetylation but not in the activation of the survival pathway proteins. Split-dose administration of VPA resulted in similar results to a single full dose. Survival was as follows: 87.5% with 300 and 250 mg/kg of VPA, 50% with 200 mg/kg of VPA, and 14% with vehicle-treated animals. CONCLUSIONS Although higher doses of VPA result in greater histone acetylation and activation of prosurvival protein signaling, doses as low as 250 mg/kg of VPA confer the same survival advantage in lethal hemorrhagic shock. Also, VPA can be given in a split-dose fashion without a reduction in its cytoprotective effectiveness.
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Affiliation(s)
- John O Hwabejire
- Division of Trauma, Emergency Surgery and Surgical Critical Care, Department of Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts
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166
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Hernandez VJ, Weng J, Ly P, Pompey S, Dong H, Mishra L, Schwarz M, Anderson RGW, Michaely P. Cavin-3 dictates the balance between ERK and Akt signaling. eLife 2013; 2:e00905. [PMID: 24069528 PMCID: PMC3780650 DOI: 10.7554/elife.00905] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Accepted: 08/14/2013] [Indexed: 12/22/2022] Open
Abstract
Cavin-3 is a tumor suppressor protein of unknown function. Using both in vivo and in vitro approaches, we show that cavin-3 dictates the balance between ERK and Akt signaling. Loss of cavin-3 increases Akt signaling at the expense of ERK, while gain of cavin-3 increases ERK signaling at the expense Akt. Cavin-3 facilitates signal transduction to ERK by anchoring caveolae to the membrane skeleton of the plasma membrane via myosin-1c. Caveolae are lipid raft specializations that contain an ERK activation module and loss of the cavin-3 linkage reduces the abundance of caveolae, thereby separating this ERK activation module from signaling receptors. Loss of cavin-3 promotes Akt signaling through suppression of EGR1 and PTEN. The in vitro consequences of the loss of cavin-3 include induction of Warburg metabolism (aerobic glycolysis), accelerated cell proliferation, and resistance to apoptosis. The in vivo consequences of cavin-3 knockout are increased lactate production and cachexia. DOI:http://dx.doi.org/10.7554/eLife.00905.001.
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Affiliation(s)
- Victor J Hernandez
- Department of Cell Biology , University of Texas Southwestern Medical Center , Dallas , United States
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167
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Sarosiek KA, Ni Chonghaile T, Letai A. Mitochondria: gatekeepers of response to chemotherapy. Trends Cell Biol 2013; 23:612-9. [PMID: 24060597 DOI: 10.1016/j.tcb.2013.08.003] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 08/05/2013] [Accepted: 08/06/2013] [Indexed: 11/18/2022]
Abstract
Mitochondria are cellular organelles that regulate commitment to and execution of apoptosis. The intrinsic apoptotic pathway culminates in the permeabilization of the mitochondrial outer membrane and dismantling of the cell. Apoptosis of cancer cells is a favorable outcome when administering chemotherapeutic treatment, yet the basis for why some cancers are sensitive to chemotherapy whereas others are not has historically been poorly understood. In this review, we present recent work that has demonstrated the importance of mitochondrial apoptotic priming, or how close a cell is to the threshold of apoptosis, in determining whether a cell will undergo apoptosis after chemotherapy treatment. Differential levels of apoptotic priming in tumors create bona fide opportunities and challenges for effective use of targeted and cytotoxic chemotherapies.
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Affiliation(s)
- Kristopher A Sarosiek
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Harvard Medical School, Boston, MA 02115, USA
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168
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Berglund F, Weerasinghe NR, Davidson L, Lim JC, Eickholt BJ, Leslie NR. Disruption of epithelial architecture caused by loss of PTEN or by oncogenic mutant p110α/PIK3CA but not by HER2 or mutant AKT1. Oncogene 2013; 32:4417-26. [PMID: 23085752 PMCID: PMC3648380 DOI: 10.1038/onc.2012.459] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 08/17/2012] [Accepted: 08/19/2012] [Indexed: 12/15/2022]
Abstract
Genetic changes in HER2, PTEN, PIK3CA and AKT1 are all common in breast cancer and lead to the elevated phosphorylation of downstream targets of the PI3K/AKT signalling pathway. Changes in HER2, PTEN, PIK3CA and AKT have all been reported to lead to both enhanced proliferation and failures in hollow lumen formation in three dimensional epithelial culture models, but it is not clear whether these failures in lumen formation are caused by any failure in the spatial coordination of lumen formation (hollowing) or purely a failure in the apoptosis and clearance of luminal cells (cavitation). Here, we use normal murine mammary gland (NMuMG) epithelial cells, which form a hollow lumen without significant apoptosis, to compare the transformation by these four genetic changes. We find that either mutant PIK3CA expression or PTEN loss, but not mutant AKT1 E17K, cause disrupted epithelial architecture, whereas HER2 overexpression drives strong proliferation without affecting lumen formation in these cells. We also show that PTEN requires both lipid and protein phosphatase activity, its extreme C-terminal PDZ binding sequence and probably Myosin 5A to control lumen formation through a mechanism that does not correlate with its ability to control AKT, but which is selectively lost through mutation in some tumours. These findings correlate AKT-independent signalling activated by mutant PIK3CA or PTEN loss, but not strongly by HER2, with disrupted epithelial architecture and tumour formation.
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Affiliation(s)
- Fredrik Berglund
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Nimmi R. Weerasinghe
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Lindsay Davidson
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Joseph C. Lim
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Britta J. Eickholt
- Charité – Universitätsmedizin Berlin, Cluster of Excellence NeuroCure and Institute of Biochemistry, 10115 Berlin, Germany
| | - Nick R. Leslie
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
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169
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Shimura T, Fukumoto M, Kunugita N. The role of cyclin D1 in response to long-term exposure to ionizing radiation. Cell Cycle 2013; 12:2738-43. [PMID: 23974042 DOI: 10.4161/cc.25746] [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: 01/11/2023] Open
Abstract
The health-related hazards resulting from long-term exposure to radiation remain unknown. Thus, an appropriate molecular marker is needed to clarify these effects. Cyclin D1 regulates the cell cycle transition from the G 1 phase to the S phase. Cyclin D1 is degraded as a G1/S checkpoint after 10 Gy of single acute radiation exposure, whereas conversely, cyclin D1 is stabilized when human tumor cells are exposed to fractionated radiation (FR) with 0.5 Gy of x-rays for 31 d. In this article, we review new findings regarding cyclin D1 overexpression in response to long-term exposure to FR. Cyclin D1 overexpression is associated with induction of genomic instability in irradiated cells. Therefore, repression of cyclin D1 expression is likely to cancel the harmful effects of long-term exposure to FR. Thus cyclin D1 may be a marker of long-term exposure to radiation and is a putative molecular radioprotection target for radiation safety.
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Affiliation(s)
- Tsutomu Shimura
- Department of Environmental Health; National Institute of Public Health 2-3-6 Minami; Wako, Saitama, Japan
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170
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171
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Suppression of apoptosis by pseudorabies virus Us3 protein kinase through the activation of PI3-K/Akt and NF-κB pathways. Res Vet Sci 2013; 95:764-74. [PMID: 23835241 DOI: 10.1016/j.rvsc.2013.06.003] [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] [Received: 01/29/2013] [Revised: 05/29/2013] [Accepted: 06/02/2013] [Indexed: 12/22/2022]
Abstract
The pseudorabies virus (PRV) is a major viral disease that causes huge economic loss in the pig industry globally. Most viruses have been found to generate anti-apoptotic factors that facilitate cell survival in the early stages of infection. This study aimed to investigate the anti-apoptotic effects of PRV and study the underlying mechanisms in the early stage of infection. We investigated and compared whether the two PRV Us3 isoforms, Us3a and Us3b, could block apoptosis induced by virus infection, and further identified molecules involved in the signaling pathways. Our results demonstrated that PRV elicits 3-phosphoinositide dependent protein kinase-1/phosphatidylinositide 3-kinases/Akt (PDK-1/PI3-K/Akt)- and nuclear factor-κB (NF-κB)-dependent signaling in the early stage of infection. Inhibition of the PI3-K/Akt or NF-κB pathway enhanced cell death but no effect was observed on virus replication or PRV gene expression. Transiently-expressed GFP- or His-tagged PRV Us3a and Us3b cDNA protect cells against PRV-, avian reovirus- or bovine ephemeral fever virus-induced apoptosis in the cell lines. Us3a and Us3b transient over-expression upregulated several anti-apopototic signaling events, and the anti-apoptosis activity of Us3a is greater than that of Us3b. Kinase activity-deficient point or double point mutated Us3a lost the kinase activity of Us3a, which showed that kinase activity is required for the anti-apoptosis effect of Us3. Akt and NF-κB activation still occurred in UV-inactivated PRV- and cycloheximide-treated cells. In vivo study showed that PRV-infected trigeminal ganglion increases the expression of anti-apoptosis signaling molecules, including Akt, PDK-1 and IκBα, which is a similar result to that seen in the in vitro experiments. Our study suggests that signaling mechanisms may play important roles in PRV pathogenesis.
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172
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Raimondi C, Falasca M. Phosphoinositides signalling in cancer: focus on PI3K and PLC. Adv Biol Regul 2013; 52:166-82. [PMID: 22019900 DOI: 10.1016/j.advenzreg.2011.09.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Accepted: 09/13/2011] [Indexed: 12/19/2022]
Affiliation(s)
- Claudio Raimondi
- Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Blizard Institute, Centre for Diabetes, Inositide Signalling Group, London E1 2AT, UK
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173
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Bonsignore A, Warburton D. The mechanisms responsible for exercise intolerance in early-stage breast cancer: What role does chemotherapy play? Hong Kong Physiother J 2013. [DOI: 10.1016/j.hkpj.2013.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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174
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Abstract
Recent evidence shows that lipid raft membrane domains modulate both cell survival and death. Here, we have found that the phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway is present in the lipid rafts of mantle cell lymphoma (MCL) cells, and this location seems to be critical for full activation and MCL cell survival. The antitumor lipids (ATLs) edelfosine and perifosine target rafts, and we found that ATLs exerted in vitro and in vivo antitumor activity against MCL cells by displacing Akt as well as key regulatory kinases p-PDK1 (phosphatidylinositol-dependent protein kinase 1), PI3K and mTOR (mammalian TOR) from lipid rafts. This raft reorganization led to Akt dephosphorylation, while proapoptotic Fas/CD95 death receptor was recruited into rafts. Raft integrity was critical for Ser473 Akt phosphorylation. ATL-induced apoptosis appeared to correlate with the basal Akt phosphorylation status in MCL cell lines and primary cultures, and could be potentiated by the PI3K inhibitor wortmannin, or inhibited by the Akt activator pervanadate. Classical Akt inhibitors induced apoptosis in MCL cells. Microenvironmental stimuli, such as CD40 ligation or stromal cell contact, did not prevent ATL-induced apoptosis in MCL cell lines and patient-derived cells. These results highlight the role of raft-mediated PI3K/Akt signaling in MCL cell survival and chemotherapy, thus becoming a new target for MCL treatment.
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175
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Zhang J, Shemezis JR, McQuinn ER, Wang J, Sverdlov M, Chenn A. AKT activation by N-cadherin regulates beta-catenin signaling and neuronal differentiation during cortical development. Neural Dev 2013; 8:7. [PMID: 23618343 PMCID: PMC3658902 DOI: 10.1186/1749-8104-8-7] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 04/05/2013] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND During cerebral cortical development, neural precursor-precursor interactions in the ventricular zone neurogenic niche coordinate signaling pathways that regulate proliferation and differentiation. Previous studies with shRNA knockdown approaches indicated that N-cadherin adhesion between cortical precursors regulates β-catenin signaling, but the underlying mechanisms remained poorly understood. RESULTS Here, with conditional knockout approaches, we find further supporting evidence that N-cadherin maintains β-catenin signaling during cortical development. Using shRNA to N-cadherin and dominant negative N-cadherin overexpression in cell culture, we find that N-cadherin regulates Wnt-stimulated β-catenin signaling in a cell-autonomous fashion. Knockdown or inhibition of N-cadherin with function-blocking antibodies leads to reduced activation of the Wnt co-receptor LRP6. We also find that N-cadherin regulates β-catenin via AKT, as reduction of N-cadherin causes decreased AKT activation and reduced phosphorylation of AKT targets GSK3β and β-catenin. Inhibition of AKT signaling in neural precursors in vivo leads to reduced β-catenin-dependent transcriptional activation, increased migration from the ventricular zone, premature neuronal differentiation, and increased apoptotic cell death. CONCLUSIONS These results show that N-cadherin regulates β-catenin signaling through both Wnt and AKT, and suggest a previously unrecognized role for AKT in neuronal differentiation and cell survival during cortical development.
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Affiliation(s)
- Jianing Zhang
- Department of Pathology, University of Illinois, 909 S, Wolcott Ave., Chicago, IL 60612, USA
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176
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Gonzalez OA, Novak MJ, Kirakodu S, Stromberg AJ, Shen S, Orraca L, Gonzalez-Martinez J, Ebersole JL. Effects of aging on apoptosis gene expression in oral mucosal tissues. Apoptosis 2013; 18:249-59. [PMID: 23334583 PMCID: PMC3592930 DOI: 10.1007/s10495-013-0806-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Apoptotic processes are important for physiologic renewal of an intact epithelial barrier and contribute some antimicrobial resistance for bacteria and viruses, as well as anti-inflammatory effects that benefits the mucosa. The oral cavity presents a model of host-bacterial interactions at mucosal surfaces, in which a panoply of microorganisms colonizes various niches in the oral cavity and creates complex multispecies biofilms that challenge the gingival tissues. This report details gene expression in apoptotic pathways that occur in oral mucosal tissues across the lifespan, using a nonhuman primate model. Macaca mulatta primates from 2 to 23 years of age (n = 23) were used in a cross-sectional study to obtain clinical healthy gingival tissues specimens. Further, mRNA was prepared and evaluated using the Affymetrix Rhesus GeneChip and 88 apoptotic pathway genes were evaluated. The results identified significant positive correlations with age in 12 genes and negative correlations with an additional five genes. The gene effects were predicted to alter apoptosis receptor levels, extrinsic apoptotic pathways through caspases, cytokine effects on apoptotic events, Ca(+2)-induced death signaling, cell cycle checkpoints, and potential effects of survival factors. Both the positively and negatively correlated genes within the apoptotic pathways provided evidence that healthy tissues in aging animals exhibit decreased apoptotic potential compared to younger animals. The results suggested that decreased physiologic apoptotic process in the dynamic septic environment of the oral mucosal tissues could increase the risk of aging tissues to undergo destructive disease processes through dysregulated inflammatory responses to the oral microbial burden.
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Affiliation(s)
- Octavio A Gonzalez
- Center for Oral Health Research, College of Dentistry, University of Kentucky, 1095 VA Drive, HSRB 414, Lexington, KY 40536-0305, USA.
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177
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Leblanc F, Zhang D, Liu X, Loughran TP. Large granular lymphocyte leukemia: from dysregulated pathways to therapeutic targets. Future Oncol 2013; 8:787-801. [PMID: 22830400 DOI: 10.2217/fon.12.75] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Large granular lymphocyte (LGL) leukemia is a clonal lymphoproliferative disorder of cytotoxic lymphocytes characterized by an expansion of CD3(+) cytotoxic T lymphocytes or CD3(-) natural killer cells. Patients present with various cytopenias including neutropenia, anemia and thrombocytopenia. In addition, there is an association of T-cell large granular lymphocytic leukemia with rheumatoid arthritis. It is believed that LGL leukemia begins as an antigen-driven immune response with subsequent constitutive activation of cytotoxic T lymphocytes or natural killer cells through PDGF and IL-15 contributing to their survival. Consequently, this leads to a dysregulation of apoptosis and dysfunction of the activation-induced cell death pathway. Treatment of LGL leukemia is based on a low-dose immunosuppressive regimen using methotrexate or cyclophosphamide. However, no standard of therapy has been established, as large prospective trials have not been conducted. In addition, some patients are refractory to treatment. The lack of a curative therapy for LGL leukemia means that new treatment options are needed. Insight into the various dysregulated signaling pathways in LGL leukemia may provide novel therapeutic treatment modalities.
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Affiliation(s)
- Francis Leblanc
- Penn State Hershey Cancer Institute, Experimental Therapeutics, Room 4427, 500 University Drive, PO Box 850, Hershey, PA 17033-0850, USA
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178
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Abstract
A recently discovered protein phosphatase PHLPP (PH domain Leucine-rich repeat Protein Phosphatase) has been shown to dephosphorylate Akt on its hydrophobic motif (Ser473) thereby decreasing Akt kinase activity. We generated PHLPP1 knockout (KO) mice and used them to explore the ability of enhanced in vivo Akt signaling to protect the brain against ischemic insult. Brains from KO mice subjected to middle cerebral artery occlusion (MCAO) for 2 hours showed significantly greater increases in Akt activity and less neurovascular damage after reperfusion than wild-type (WT) mice. Remarkably, infarct volume in the PHLPP1 KO was significantly reduced compared with WT (12.7±2.7% versus 22.9±3.1%) and this was prevented by Akt inhibition. Astrocytes from KO mice and neurons in which PHLPP1 was downregulated showed enhanced Akt activation and diminished cell death in response to oxygen-glucose deprivation. Thus, deletion of PHLPP1 can enhance Akt activation in neurons and astrocytes, and can significantly increase cell survival and diminish infarct size after MCAO. Inhibition of PHLPP could be a therapeutic approach to minimize damage after focal ischemia.
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179
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Kalvelyte A, Krestnikova N, Stulpinas A, Bukelskiene V, Bironaite D, Baltriukiene D, Imbrasaite A. Long-term muscle-derived cell culture: multipotency and susceptibility to cell death stimuli. Cell Biol Int 2013; 37:292-304. [PMID: 23359426 DOI: 10.1002/cbin.10036] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Accepted: 12/03/2012] [Indexed: 11/06/2022]
Abstract
Improvement in the yield of adult organism stem cells, and the ability to manage their differentiation and survival potential are the major goals in their application in regenerative medicine and in the adult stem cell research. We have demonstrated that adult rabbit muscle-derived cell lines with an unlimited proliferative potential in vitro can differentiate into myogenic, osteogenic, adipogenic and neurogenic lineages. Studies of cell survival in vitro showed that differentiated cells, except neurogenic ones, are more resistant to apoptosis inducers compared to proliferating cells. Resistance to death signals correlated with the level of protein kinase AKT phosphorylation. Skeletal muscle-derived cell lines can be multipurpose tools in therapy. Enhanced resistance of differentiated cells to certain types of damage shows their potential for long-term survival and maintenance in an organism. This article was published online on 29 January 2013. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 6 March 2013.
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Affiliation(s)
- Audrone Kalvelyte
- Vilnius University Institute of Biochemistry Mokslininku str. 12, LT-08662, Vilnius, Lithuania
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180
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Brassesco MS, Pezuk JA, Morales AG, de Oliveira JC, Valera ET, da Silva GN, de Oliveira HF, Scrideli CA, Umezawa K, Tone LG. Cytostatic in vitro effects of DTCM-glutarimide on bladder carcinoma cells. Asian Pac J Cancer Prev 2013; 13:1957-62. [PMID: 22901154 DOI: 10.7314/apjcp.2012.13.5.1957] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Bladder cancer is a common malignancy worldwide. Despite the increased use of cisplatin-based combination therapy, the outcomes for patients with advanced disease remain poor. Recently, altered activation of the PI3K/ Akt/mTOR pathway has been associated with reduced patient survival and advanced stage of bladder cancer, making its upstream or downstream components attractive targets for therapeutic intervention. In the present study, we showed that treatment with DTCM-glutaramide, a piperidine that targets PDK1, results in reduced proliferation, diminished cell migration and G1 arrest in 5637 and T24 bladder carcinoma cells. Conversely, no apoptosis, necrosis or autophagy were detected after treatment, suggesting that reduced cell numbers in vitro are a result of diminished proliferation rather than cell death. Furthermore previous exposure to 10 μg/ml DTCM- glutarimide sensitized both cell lines to ionizing radiation. Although more studies are needed to corroborate our findings, our results indicate that PDK1 may be useful as a therapeutic target to prevent progression and abnormal tissue dissemination of urothelial carcinomas.
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Affiliation(s)
- María S Brassesco
- Division of Pediatric Oncology, Department of Pediatrics, Faculty of Medicine of Ribeirao Preto, University of São Paulo-USP, Brazil.
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181
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Quan JH, Cha GH, Zhou W, Chu JQ, Nishikawa Y, Lee YH. Involvement of PI 3 kinase/Akt-dependent Bad phosphorylation in Toxoplasma gondii-mediated inhibition of host cell apoptosis. Exp Parasitol 2013; 133:462-71. [PMID: 23333591 DOI: 10.1016/j.exppara.2013.01.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 12/17/2012] [Accepted: 01/03/2013] [Indexed: 11/25/2022]
Abstract
Toxoplasma gondii-infected cells are resistant to various apoptotic stimuli, however, the role of the pro-apoptotic BH3-only Bad protein in T. gondii-imposed inhibition of host cell apoptosis in connection with the phosphoinositide 3-kinase (PI3K)-PKB/Akt pathway was not well delineated. Here, we investigated the signaling patterns of Bad, Bax and PKB/Akt in T. gondii-infected and uninfected THP-1 cells treated with staurosporine (STS) or PI3K inhibitors. STS treatment, without T. gondii infection, reduced the viability of THP-1 cells in proportion to STS concentration and triggered many cellular death events such as caspase-3 and -9 activation, Bax translocation, cytochrome c release from host cell mitochondria into cytosol, and PARP cleavage in the host cell. However, T. gondii infection eliminated the STS-triggered mitochondrial apoptotic events described above. Additionally, T. gondii infection in vitro and in vivo induced the phosphorylation of PKB/Akt and Bad in a parasite-load-dependent manner which subsequently inhibited Bax translocation. The PI3K inhibitors, LY294002 and Wortmannin, both blocked parasite-induced phosphorylation of PKB/Akt and Bad. Furthermore, THP-1 cells pretreated with these PI3K inhibitors showed reduced phosphorylation of Bad in a dose-dependent manner and subsequently failed to inhibit the Bax translocation, also these cells also failed to overcome the T. gondii-imposed inhibition of host cell apoptosis. These data demonstrate that the PI3K-PKB/Akt pathway may be one of the major route for T. gondii in the prevention of host cell apoptosis and T. gondii phosphorylates the pro-apoptotic Bad protein to prevent apoptosis.
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Affiliation(s)
- Juan-Hua Quan
- Department of Infection Biology and Research Institute for Medical Sciences, Chungnam National University School of Medicine, Daejeon 301-131, South Korea
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182
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Goldsmith JR, Perez-Chanona E, Yadav PN, Whistler J, Roth B, Jobin C. Intestinal epithelial cell-derived μ-opioid signaling protects against ischemia reperfusion injury through PI3K signaling. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 182:776-85. [PMID: 23291213 DOI: 10.1016/j.ajpath.2012.11.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 09/28/2012] [Accepted: 11/12/2012] [Indexed: 12/30/2022]
Abstract
Intestinal ischemia has a wide variety of causes, including, but not limited to, atherosclerosis, thrombosis, hypotension, and chronic inflammation. In severe cases, ischemic injury can result in death. μ-Opioid receptor (MOR) signaling has previously been shown to protect against chemically induced colitis, but the cellular origin of this effect remains unknown. Herein, we evaluated the role of intestinal epithelial cell (IEC)-derived MOR signaling in host responses to ischemia/reperfusion-induced injury. Ileal ischemia was accomplished through obstruction of the distal branches of the superior mesenteric artery (60 minutes) and reperfusion for 90 minutes (ischemia-reperfusion). Floxed-MOR mice were crossed to Villin-cre transgenic mice to selectively delete the MOR gene in IECs (MOR(IEC-/-)). Radio-ligand binding assays demonstrated selective loss of MOR signaling in IECs of MOR(IEC-/-) mice. The s.c. administration of the MOR agonist, [D-Arg2, Lys4] dermorphin (1-4) amide (DALDA), 10 minutes before surgery protected against both ischemic and reperfusion phases of intestinal injury, an effect abolished in MOR(IEC-/-) mice. This cytoprotective effect was associated with enterocyte-mediated phosphoinositide 3-kinase (PI3K)/glycogen synthase kinase 3β signaling and decreased apoptosis, as determined by IHC and caspase-3 processing. PI3K blockade with Ly294002 resulted in loss of MOR-mediated cytoprotective function. Together, these data show that IEC-derived μ-opioid signaling uses the PI3K pathway to protect cells against the damaging effect of ischemia-reperfusion. Targeting MOR signaling may represent a novel mean to alleviate intestinal injury and promote the wound-healing response.
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Affiliation(s)
- Jason R Goldsmith
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599, USA
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183
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Riese A, Eilert Y, Meyer Y, Arin M, Baron JM, Eming S, Krieg T, Kurschat P. Epidermal expression of neuropilin 1 protects murine keratinocytes from UVB-induced apoptosis. PLoS One 2012; 7:e50944. [PMID: 23251405 PMCID: PMC3518474 DOI: 10.1371/journal.pone.0050944] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 10/29/2012] [Indexed: 01/13/2023] Open
Abstract
Background Neuropilin 1 (NRP1) is expressed on several cell types including neurons and endothelial cells, where it functions as an important regulator in development and during angiogenesis. As a cell surface receptor, NRP1 is able to bind to members of the VEGF family of growth factors and to secreted class 3 semaphorins. Neuropilin 1 is also highly expressed in keratinocytes, but the function of NRP1 in epidermal physiology and pathology is still unclear. Methods and Results To elucidate the role of NRP1 in skin in vivo we generated an epidermis-specific neuropilin 1 knock out mouse model by using the Cre-LoxP-System. Mice were viable and fertile and did not display any obvious skin or hair defects. After challenge with UVB irradiation, we found that deletion of epidermal NRP1 leads to increased rates of apoptosis both in vitro and in vivo. NRP1-deficient primary keratinocytes cultured in vitro showed significantly higher rates of apoptosis 24 hours after UVB. Likewise, there is a significant increase of active caspase 3 positive cells in the epidermis of Keratin 14-Cre-NRP1 (−/−) mice 24 hours after UVB irradiation. By Western Blot analysis we could show that NRP1 influences the cytosolic levels of Bcl-2, a pro-survival member of the Bcl-2 family. After UVB irradiation the amounts of Bcl-2 decrease in both protein extracts from murine epidermis and in NRP1-deficient keratinocytes in vitro, whereas wild type cells retain their Bcl-2 levels. Likewise, levels of phospho-Erk and Rac1 were lower in NRP1-knock out keratinocytes, whereas levels of pro-apoptotic p53 were higher. Conclusion NRP1 expression in keratinocytes is dispensable for normal skin development. Upon UVB challenge, NRP1 contributes to the prevention of keratinocyte apoptosis. This pro-survival function of NRP1 is accompanied by the maintenance of high levels of the antiapoptotic regulator Bcl-2 and by lower levels of pro-apoptotic p53.
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Affiliation(s)
- Anna Riese
- Department of Dermatology and Venerology, University Hospital of Cologne, Cologne, Germany
| | - Yvonne Eilert
- Department of Dermatology and Venerology, University Hospital of Cologne, Cologne, Germany
| | - Yvonne Meyer
- Department of Dermatology and Venerology, University Hospital of Cologne, Cologne, Germany
| | - Meral Arin
- Department of Dermatology and Venerology, University Hospital of Cologne, Cologne, Germany
| | - Jens M. Baron
- Department of Dermatology and Allergology, RWTH Aachen, Aachen, Germany
| | - Sabine Eming
- Department of Dermatology and Venerology, University Hospital of Cologne, Cologne, Germany
| | - Thomas Krieg
- Department of Dermatology and Venerology, University Hospital of Cologne, Cologne, Germany
| | - Peter Kurschat
- Department of Dermatology and Venerology, University Hospital of Cologne, Cologne, Germany
- * E-mail:
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184
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Pérez-Schindler J, Philp A, Hernandez-Cascales J. Pathophysiological relevance of the cardiac β2-adrenergic receptor and its potential as a therapeutic target to improve cardiac function. Eur J Pharmacol 2012. [PMID: 23183106 DOI: 10.1016/j.ejphar.2012.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
β-adrenoceptors are members of the G protein-coupled receptor superfamily which play a key role in the regulation of myocardial function. Their activation increases cardiac performance but can also induce deleterious effects such as cardiac arrhythmias or myocardial apoptosis. In fact, inhibition of β-adrenoceptors exerts a protective effect in patients with sympathetic over-stimulation during heart failure. Although β(2)-adrenoceptor is not the predominant subtype in the heart, it seems to importantly contribute to the cardiac effects of adrenergic stimulation; however, the mechanism by which this occurs is not fully understood. This review summarizes the current knowledge on the role of β(2)-adrenoceptors in the regulation of cardiac contractility, metabolism, cardiomyocyte survival and cardiac arrhythmias. In addition, therapeutic considerations relating to stimulation of the β(2)-adrenoceptor such as an increase in cardiac contractility with low arrythmogenic effect, protection of the myocardium again apoptosis or positive regulation of heart metabolism are discussed.
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185
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Sarris EG, Saif MW, Syrigos KN. The Biological Role of PI3K Pathway in Lung Cancer. Pharmaceuticals (Basel) 2012; 5:1236-64. [PMID: 24281308 PMCID: PMC3816662 DOI: 10.3390/ph5111236] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Revised: 11/07/2012] [Accepted: 11/14/2012] [Indexed: 12/31/2022] Open
Abstract
Lung cancer is the primary cause of cancer-related mortality worldwide and although improvements in treatment have been achieved over the last few years, long-term survival rates for lung cancer patients remain poor. Therefore, there is an imperative need for molecularly targeted agents that will achieve long-term disease control. Numerous downstream molecular pathways, such as EGF/RAS/RAF/MEK/ERK and PI3K/AKT/mTOR are identified as having a key role in the pathogenesis of various forms of human cancer, including lung cancer. PI3K/AKT/mTOR signal pathway is an important intracellular signal transduction pathway with a significant role in cell proliferation, growth, survival, vesicle trafficking, glucose transport, and cytoskeletal organization. Aberrations in many primary and secondary messenger molecules of this pathway, including mutations and amplifications, are accounted for tumor cell proliferation, inhibition of apoptosis, angiogenesis, metastasis and resistance to chemotherapy-radiotherapy. In this review article, we investigate thoroughly the biological role of PI3K pathway in lung cancer and its contribution in the development of future therapeutic strategies.
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Affiliation(s)
- Evangelos G. Sarris
- Oncology Unit GPP, 3rd Dept of Medicine, Sotiria General Hospital, University of Athens, Athens 11527, Greece;
| | - Muhammad W. Saif
- Experimental Therapeutics Program, Division of Hematology/Oncology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA 02111, USA;
| | - Kostas N. Syrigos
- Oncology Unit GPP, 3rd Dept of Medicine, Sotiria General Hospital, University of Athens, Athens 11527, Greece;
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186
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Beauséjour M, Noël D, Thibodeau S, Bouchard V, Harnois C, Beaulieu JF, Demers MJ, Vachon PH. Integrin/Fak/Src-mediated regulation of cell survival and anoikis in human intestinal epithelial crypt cells: selective engagement and roles of PI3-K isoform complexes. Apoptosis 2012; 17:566-78. [PMID: 22402981 PMCID: PMC3345181 DOI: 10.1007/s10495-012-0713-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In human intestinal epithelial crypt (HIEC) cells, the PI3-K/Akt-1 pathway is crucial for the promotion of cell survival and suppression of anoikis. Class I PI3-K consists of a complex formed by a catalytic (C) and regulatory (R) subunit. Three R (p85α, β, and p55γ) and four C (p110α, β, γ and δ) isoforms are known. Herein, we analyzed the expression of PI3-K isoforms in HIEC cells and determined their roles in cell survival, as well as in the β1 integrin/Fak/Src-mediated suppression of anoikis. We report that: (1) the predominant PI3-K complexes expressed by HIEC cells are p110α/p85β and p110α/p55γ; (2) the inhibition and/or siRNA-mediated expression silencing of p110α, but not that of p110β, γ or δ, results in Akt-1 down-activation and consequent apoptosis; (3) the expression silencing of p85β or p55γ, but not that of p85α, likewise induces Akt-1 down-activation and apoptosis; however, the impact of a loss of p55γ on both Akt-1 activation and cell survival is significantly greater than that from the loss of p85β; and (4) both the p110α/p85β and p110α/p55γ complexes are engaged by β1 integrin/Fak/Src signaling; however, the engagement of p110α/p85β is primarily Src-dependent, whereas that of p110α/p55γ is primarily Fak-dependent (but Src-independent). Hence, HIEC cells selectively express PI3-K isoform complexes, translating into distinct roles in Akt-1 activation and cell survival, as well as in a selective engagement by Fak and/or Src within the context of β1 integrin/Fak/Src-mediated suppression of anoikis.
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Affiliation(s)
- Marco Beauséjour
- Département d'anatomie et de Biologie Cellulaire, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
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187
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HSP70 increases extracellular matrix production by human vascular smooth muscle through TGF-β1 up-regulation. Int J Biochem Cell Biol 2012; 45:232-42. [PMID: 23084979 DOI: 10.1016/j.biocel.2012.10.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 09/04/2012] [Accepted: 10/09/2012] [Indexed: 01/01/2023]
Abstract
The circulating levels of heat shock proteins (HSP) are increased in cardiovascular diseases; however, the implication of this for the fibrotic process typical of such diseases remains unclear. HSP70 can interact with the vascular smooth muscle cells (SMC), the major producer of extracellular matrix (ECM) proteins, through the Toll-like receptors 4 (TLR4). The transforming growth factor type-β1 (TGF-β1) is a well known vascular pro-fibrotic cytokine that is regulated in part by AP-1-dependent transcriptional mechanisms. We hypothesized that extracellular HSP70 could interact with SMCs, inducing TGF-β1 synthesis and subsequent changes in the vascular ECM. We demonstrate that extracellular HSP70 binds to human aorta SMC TLR4, which up-regulates the AP-1-dependent transcriptional activity of the TGF-β1 promoter. This is achieved through the mitogen activated protein kinases JNK and ERK, as demonstrated by the use of specific blockers and the knockdown of TLR4 with specific small interfering RNAs. The TGF-β1 upregulation increase the expression of the ECM proteins type I collagen and fibronectin. This novel observation may elucidate the mechanisms by which HSP70 contributes in the inflammation and fibrosis present in atherosclerosis and other fibrosis-related diseases.
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188
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p53 is a major component of the transcriptional and apoptotic program regulated by PI 3-kinase/Akt/GSK3 signaling. Cell Death Dis 2012; 3:e400. [PMID: 23059819 PMCID: PMC3481126 DOI: 10.1038/cddis.2012.138] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The phosphatidylinositol (PI) 3-kinase/Akt signaling pathway has a prominent role in cell survival and proliferation, in part, by regulating gene expression at the transcriptional level. Previous work using global expression profiling identified FOXOs and the E-box-binding transcription factors MITF and USF1 as key targets of PI 3-kinase signaling that lead to the induction of proapoptotic and cell cycle arrest genes in response to inhibition of PI 3-kinase. In this study, we investigated the role of p53 downstream of PI 3-kinase signaling by analyzing the effects of inhibition of PI 3-kinase in Rat-1 cells, which have wild-type p53, compared with Rat-1 cells expressing a dominant-negative p53 mutant. Expression of dominant-negative p53 conferred partial resistance to apoptosis induced by inhibition of PI 3-kinase. Global gene expression profiling combined with computational and experimental analysis of transcription factor binding sites demonstrated that p53, along with FOXO, MITF and USF1, contributed to gene induction in response to PI 3-kinase inhibition. Activation of p53 was mediated by phosphorylation of the histone acetyltransferase Tip60 by glycogen synthase kinase (GSK) 3, leading to activation of p53 by acetylation. Many of the genes targeted by p53 were also targeted by FOXO and E-box-binding transcription factors, indicating that p53 functions coordinately with these factors to regulate gene expression downstream of PI 3-kinase/Akt/GSK3 signaling.
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189
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Sacco E, Spinelli M, Vanoni M. Approaches to Ras signaling modulation and treatment of Ras-dependent disorders: a patent review (2007--present). Expert Opin Ther Pat 2012; 22:1263-87. [PMID: 23009088 DOI: 10.1517/13543776.2012.728586] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
INTRODUCTION Ras proteins are small GTPases molecular switches that cycle through two alternative conformational states, a GDP-bound inactive state and a GTP-bound active state. In the active state, Ras proteins interact with and modulate the activity of several downstream effectors regulating key cellular processes including proliferation, differentiation, survival, senescence, migration and metabolism. Activating mutations of RAS genes and of genes encoding Ras signaling members have a great incidence in proliferative disorders, such as cancer, immune and inflammatory diseases and developmental syndromes. Therefore, Ras and Ras signaling represent important clinical targets for the design and development of pharmaceutically active agents, including anticancer agents. AREAS COVERED The authors summarize methods available to down-regulate the Ras pathway and review recent patents covering Ras signaling modulators, as well as methods designed to kill specifically cancer cells bearing activated RAS oncogene. EXPERT OPINION Targeted therapy approach based on direct targeting of molecules specifically altered in Ras-dependent diseases is pursued with molecules that down-regulate expression or inhibit the biological function of mutant Ras or Ras signaling members. The low success rate in a clinical setting of molecules targeting activated members of the Ras pathway may require development of novel approaches, including combined and synthetic lethal therapies.
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Affiliation(s)
- Elena Sacco
- University of Milano-Bicocca, Department of Biotechnology and Biosciences, Milano, Italy
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190
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Wei K, Wang P, Miao CY. A double-edged sword with therapeutic potential: an updated role of autophagy in ischemic cerebral injury. CNS Neurosci Ther 2012; 18:879-86. [PMID: 22998350 DOI: 10.1111/cns.12005] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 08/22/2012] [Accepted: 08/24/2012] [Indexed: 12/15/2022] Open
Abstract
Cerebral ischemia is a severe outcome that could cause cognitive and motor dysfunction, neurodegenerative diseases and even acute death. Although the existence of autophagy in cerebral ischemia is undisputable, the consensus has not yet been reached regarding the exact functions and influence of autophagy in cerebral ischemia. Whether the activation of autophagy is beneficial or harmful in cerebral ischemia injury largely depends on the balance between the burden of intracellular substrate targeted for autophagy and the capacity of the cellular autophagic machinery. Furthermore, the mechanisms underlying the autophagy in cerebral ischemia are far from clear yet. This brief review focuses on not only the current understanding of biological effects of autophagy, but also the therapeutic potentials of autophagy in ischemic stroke. There are disputes over the exact role of autophagy in cerebral ischemia. Application of chemical autophagy inhibitor (e.g., 3-methyladenine) or inducer (e.g., rapamycin) in vitro and in vivo was reported to protect or harm neuronal cell. Knockdown of autophagic protein, such as Beclin 1, was also reported to modulate the cerebral ischemia-induced injury. Moreover, autophagy inhibitor abolished the neuroprotection of ischemic preconditioning, implying a neuroprotective effect of autophagy. To clarify these issues on autophagy in cerebral ischemia, future investigations are warranted.
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Affiliation(s)
- Kai Wei
- Department of Pharmacology, Second Military Medical University, Shanghai, China
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191
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LY294002 and metformin cooperatively enhance the inhibition of growth and the induction of apoptosis of ovarian cancer cells. Int J Gynecol Cancer 2012; 22:15-22. [PMID: 22080879 DOI: 10.1097/igc.0b013e3182322834] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND The phosphoinositide 3 kinase (PI3K)/v-akt murine thymoma viral oncogene homolog (AKT)/mammalian target of rapamycin (mTOR) pathway is frequently aberrantly activated in ovarian cancer and confers the chemoresistant phenotype of ovarian cancer cells. LY294002 (PI3K inhibitor) and metformin (5'-adenosine monophosphate [AMP]-activated protein kinase [AMPK] activator) are 2 drugs that were known to inhibit mTOR expression through the AKT-dependent and AKT-independent pathways, respectively. In this study, we explored the effectiveness of LY294002 and metformin in combination on inhibition of ovarian cancer cell growth. METHODS Western blotting was used to detect the changes of PI3K/AKT/mTOR and AMPK/acetyl-CoA carboxylase (ACC) signaling activities, cell cycle control, and apoptosis. Cell growth was evaluated by cell proliferation, colony formation, and soft agar assays. Flow cytometry was used to study cell cycle distribution and cell death upon drug treatment. RESULTS Our study showed that LY294002 and metformin in combination could simultaneously enhance the repression of the PI3K/AKT/mTOR pathway and the activation of the AMPK/ACC pathway. The downstream target of AKT and AMPK, mTOR, was cooperatively repressed when the drugs were used together. The cell cycle regulatory factors, p53, p27, and p21, were up-regulated. On the other hand, caspase 3 and poly (ADP-ribose) polymerase activities involved in apoptosis were also activated. Cell growth assays indicated that LY294002 and metformin could effectively inhibit ovarian cancer cell growth. Flow cytometry analysis showed that the treatment of the 2 drugs mentioned above induced cell cycle arrest at G1 phase and increased sub-G1 apoptotic cells. CONCLUSION The combinational use of LY294002 and metformin can enhance inhibition of the growth and induction of the apoptosis of ovarian cancer cells. Our results may provide significant insight into the future therapeutic regimens in ovarian cancer.
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192
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Protein kinases of the Hippo pathway: regulation and substrates. Semin Cell Dev Biol 2012; 23:770-84. [PMID: 22898666 DOI: 10.1016/j.semcdb.2012.07.002] [Citation(s) in RCA: 185] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 07/31/2012] [Indexed: 01/30/2023]
Abstract
The "Hippo" signaling pathway has emerged as a major regulator of cell proliferation and survival in metazoans. The pathway, as delineated by genetic and biochemical studies in Drosophila, consists of a kinase cascade regulated by cell-cell contact and cell polarity that inhibits the transcriptional coactivator Yorkie and its proliferative, anti-differentiation, antiapoptotic transcriptional program. The core pathway components are the GC kinase Hippo, which phosphorylates the noncatalytic polypeptide Mats/Mob1 and, with the assistance of the scaffold protein Salvador, phosphorylates the ndr-family kinase Lats. In turn phospho-Lats, after binding to phospho-Mats, autoactivates and phosphorylates Yorkie, resulting in its nuclear exit. Hippo also uses the scaffold protein Furry and a different Mob protein to control another ndr-like kinase, the morphogenetic regulator Tricornered. Architecturally homologous kinase cascades consisting of a GC kinase, a Mob protein, a scaffolding polypeptide and an ndr-like kinase are well described in yeast; in Saccharomyces cerevisiae, e.g., the MEN pathway promotes mitotic exit whereas the RAM network, using a different GC kinase, Mob protein, scaffold and ndr-like kinase, regulates cell polarity and morphogenesis. In mammals, the Hippo orthologs Mst1 and Mst2 utilize the Salvador ortholog WW45/Sav1 and other scaffolds to regulate the kinases Lats1/Lats2 and ndr1/ndr2. As in Drosophila, murine Mst1/Mst2, in a redundant manner, negatively regulate the Yorkie ortholog YAP in the epithelial cells of the liver and gut; loss of both Mst1 and Mst2 results in hyperproliferation and tumorigenesis that can be largely negated by reduction or elimination of YAP. Despite this conservation, considerable diversification in pathway composition and regulation is already evident; in skin, e.g., YAP phosphorylation is independent of Mst1Mst2 and Lats1Lats2. Moreover, in lymphoid cells, Mst1/Mst2, under the control of the Rap1 GTPase and independent of YAP, promotes integrin clustering, actin remodeling and motility while restraining the proliferation of naïve T cells. This review will summarize current knowledge of the structure and regulation of the kinases Hippo/Mst1&2, their noncatalytic binding partners, Salvador and the Rassf polypeptides, and their major substrates Warts/Lats1&2, Trc/ndr1&2, Mats/Mob1 and FOXO.
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193
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Zhang Y, Liu X, Zhang J, Li L, Liu C. The expression and clinical significance of PI3K, pAkt and VEGF in colon cancer. Oncol Lett 2012. [PMID: 23205098 DOI: 10.3892/ol.2012.822] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Background PI3K/Akt signaling has been shown to be activated in a variety of cancers. However, the correlation between Akt activation and VEGF expression is unclear in colon cancer tissues. This study aimed to investigate the expression and predictive value of phosphorylated Akt (pAkt) and VEGF in colon cancer tissues. The expression of PI3K, pAkt and VEGF was detected by immunohistochemical staining in 60 samples of colon cancer tissues and their corresponding adjacent normal colon tissues. In addition, the correlations between the expression levels of the 3 proteins and the clinicopathological parameters of the colon cancer cases were analyzed. The positive rates of PI3K, pAkt and VEGF expression were 71.7% (43/60), 68.3% (41/60) and 61.7% (37/60) in colon cancer, respectively, which were significantly higher than in adjacent normal colon tissues (P<0.001). Correlation analyses showed that PI3K expression was not significantly associated with the gender or age of the patients, tumor size or differentiation (P>0.05), but was closely associated with serous coat infiltration and lymphatic metastasis of colon cancer (P<0.05). Neither pAkt nor VEGF expression were significantly associated with the gender or age of the patients, or tumor differentiation (P>0.05), but were closely associated with tumor size, serous coat infiltration and lymphatic metastasis of colon cancer (P<0.05). In addition, the expression levels of Pl3K and pAkt were positively correlated with that of VEGF in colon cancer tissues (P<0.05). Our data show a positive correlation between PI3K/Akt activation and VEGF expression in colon cancer tissues and indicate that pAkt is an independent prognostic marker for colon cancer patients.
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Affiliation(s)
- Yinxu Zhang
- Department of Pathology, Liaoning University of Traditional Chinese Medicine, Shenyang 110032; ; Department of Surgery, The First Affiliated Hospital of Liaoning Medical University, Jinzhou, Liaoning 121001, P.R. China
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194
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Regan PM, Dave RS, Datta PK, Khalili K. Epigenetics of µ-opioid receptors: intersection with HIV-1 infection of the central nervous system. J Cell Physiol 2012; 227:2832-41. [PMID: 22034138 DOI: 10.1002/jcp.24004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The abuse of intravenous drugs, such as heroin, has become a major public health concern due to the increased risk of HIV-1 infection. Opioids such as heroin were originally identified and subsequently abused for their analgesic effects. However, many investigations have found additional effects of opioids, including regulation of the immune system. As such, chronic opioid abuse has been shown to promote HIV-1 pathogenesis and facilitate HIV-1-associated neurocognitive dysfunction. Clinical opioids, such as morphine and methadone, as well as illicit opioids, such as heroin, exert their effects primarily through interactions with the µ-opioid receptor (MOR). However, the mechanisms by which opioids enhance neurocognitive dysfunction through MOR-mediated signaling pathways are not completely understood. New findings in the regulation of MOR expression, particularly epigenetic and transcriptional regulation as well as alternative splicing, sheds new insights into possible mechanisms of HIV-1 and opiate synergy. In this review, we identify mechanisms regulating MOR expression and propose novel mechanisms by which opioids and HIV-1 may modulate this regulation. Additionally, we suggest that differential regulation of newly identified MOR isoforms by opioids and HIV-1 has functional consequence in enhancing HIV-1 neurocognitive dysfunction.
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Affiliation(s)
- Patrick M Regan
- Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Philadelphia, PA, USA
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195
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COX-2-independent induction of apoptosis by celecoxib and polyamine naphthalimide conjugate mediated by polyamine depression in colorectal cancer cell lines. Int J Colorectal Dis 2012; 27:861-8. [PMID: 22159752 DOI: 10.1007/s00384-011-1379-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/24/2011] [Indexed: 02/04/2023]
Abstract
BACKGROUND Polyamine metabolism is an intriguing tumor therapeutic target. The present study was designed to assess the synergistic antitumor effects of NPC-16, a novel polyamine naphthalimide conjugate, with celecoxib and to elucidate the mechanism of these effects on human colorectal cancer cells. METHODS Cell proliferation was assessed by the MTT assay. Cell apoptosis and mitochondria membrane potential were evaluated by high content screening analysis. Intracellular polyamine content was detected by HPLC. Protein expression was detected by western blot analysis. RESULTS The co-treatment with celecoxib enhanced NPC-16-induced apoptosis in HCT116 (COX-2 no expression), HT29 (COX-2 higher expression) and Caco-2 (COX-2 higher expression) colorectal cancer cells, which was mediated by the elevated NPC-16 uptake via the effect of celecoxib on polyamine metabolism, including the up-regulated spermidine/spermine N(1)-acetyltransferase (SSAT) activity and reduced intracellular polyamine levels. The presence of celecoxib does not result in obviously different effect on the NPC-16-triggered apoptosis in diverse COX-2 expressed colorectal cell lines, suggesting that COX-2 was not one vital factor in the apoptotic mechanism. Furthermore, this synergistic apoptosis was involved in the PKB/AKT signal pathway, Bcl-2 and caspase family members. Z-VAD-FMK, a cell permeable pan caspase inhibitor, almost completely inhibited celecoxib and NPC-16 co-induced apoptosis, indicating that this apoptosis was caspase dependent. CONCLUSIONS Co-treatment of celecoxib and NPC-16 could induce colorectal cancer cell apoptosis via COX-2-independent and caspase-dependent mechanisms. The combination therapy with these agents might provide a novel therapeutic model for colorectal cancer.
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Abstract
The PI3K pathway plays an important role in key cellular functions such as cell growth, proliferation and survival. Genetic and epigenetic alterations in different pathway components lead to aberrant pathway activation and have been observed in high frequencies in various tumor types. Consequently, significant effort has been made to develop antineoplastic agents targeting different nodes in this pathway. Additionally, PI3K pathway status may have predictive and prognostic implications, and may contribute to drug resistance in tumor cells. This article provides an overview of our current knowledge of the PI3K pathway with an emphasis on its application in cancer treatment.
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Affiliation(s)
- Navid Sadeghi
- Division of Hematology & Oncology, Harold C Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - David E Gerber
- Division of Hematology & Oncology, Harold C Simmons Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
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197
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Tabassam FH, Graham DY, Yamaoka Y. Helicobacter pylori-associated regulation of forkhead transcription factors FoxO1/3a in human gastric cells. Helicobacter 2012; 17:193-202. [PMID: 22515357 PMCID: PMC3335761 DOI: 10.1111/j.1523-5378.2012.00939.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Interaction of Helicobacter pylori with gastric mucosa leads to marked cellular and humoral host immunologic responses. The signaling pathways initiated by bacteria-host interaction that result in perturbations in cell structure and function remain unclear. Forkhead transcription factors of class O (FoxO) are implicated in the regulation of apoptosis, cell survival, and pathogenesis. H. pylori infection of gastric epithelial cells induces phosphoinositide-3 kinase (PI3K)-dependent Akt activation and cell survival signaling. We investigated the role of H. pylori-activated PI3K/Akt in the regulation of FoxO1/3a in gastric cells. METHODS Immunoblot, immunoprecipitation, and fluorescence microscopy were used to assess the effect of infection of gastric epithelial cells with wild-type H. pylori and their isogenic cag pathogenicity island (PAI) or oipA mutants on the FoxO1/3a signaling pathways. Interleukin-8 release was determined by enzyme-linked immunosorbent assays. RESULTS H. pylori infection resulted in activation of the PI3K p85 subunit and inactivation of FoxO1 and FoxO3a by their phosphorylation and translocation of from the nucleus to the cytoplasm. Inhibition of PI3K or Akt kinase activity reduced FoxO1/3a phosphorylation. Akt, FoxO1, or FoxO3a siRNA reduced H. pylori-induced interleukin-8 production. Infection with oipA mutants reduced PI3K/Akt activation and inhibited FoxO1/3a phosphorylation, whereas infection with cag PAI mutants reduced PI3K/Akt activity but did not inhibit FoxO1/3a activation. CONCLUSIONS FoxO1 and FoxO3a are novel nuclear substrates of H. pylori-induced PI3K/Akt cell survival signaling pathways that partially control interleukin-8 production. OipA-regulated interleukin-8 release through PI3K/Akt is dependent on FoxO1/3a inactivation, whereas cag PAI-mediated interleukin-8 production employs FoxO1/3-independent signaling.
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Affiliation(s)
- Fazal H. Tabassam
- Department of Medicine/Gastroenterology, Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, TX 77030 USA
| | - David Y. Graham
- Department of Medicine/Gastroenterology, Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, TX 77030 USA
| | - Yoshio Yamaoka
- Department of Medicine/Gastroenterology, Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, TX 77030 USA,Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Yufu, Oita 879-5593, JAPAN
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Côté N, El Husseini D, Pépin A, Bouvet C, Gilbert LA, Audet A, Fournier D, Pibarot P, Moreau P, Mathieu P. Inhibition of ectonucleotidase with ARL67156 prevents the development of calcific aortic valve disease in warfarin-treated rats. Eur J Pharmacol 2012; 689:139-46. [PMID: 22659116 DOI: 10.1016/j.ejphar.2012.05.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 04/23/2012] [Accepted: 05/15/2012] [Indexed: 02/04/2023]
Abstract
Calcific aortic valve disease is the most common heart valve disorder. So far, there is no medical treatment for calcific aortic valve disease. The expression of ectonucleotidases, which metabolize nucleotides into phosphate products, may influence the calcification of the aortic valve. In this study, we investigated if the administration of an ectonucleotidase inhibitor, ARL67156 (6-N,N-Diethyl-D-β,γ-dibromomethyleneATP trisodium salt), may prevent the calcification of the aortic valve in the warfarin-induced mineralization rat model. Male Wistar rats were treated with warfarin or warfarin+ARL67156 for 28 days. All rats had comprehensive Doppler-echocardiographic studies at 28 day. A gene profiling of ectonucleotidases expressed in aortas of rats was documented by quantitative real-time PCR. The amount of calcium was determined by quantitative method and von Kossa staining. Ex vivo cultures of rat aortas were also used to further assess the effect of ARL67156 on the calcifying process and Akt signaling. Mineralization of the aorta/aortic valve was documented in warfarin-treated rats and was accompanied by the development of aortic stenosis. These changes were paralleled by an increased of ectonucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1). Administration of the ectonucleotidase inhibitor, ARL67156 prevented the development of aortic stenosis by lowering the level of apoptosis and mineralization of the aortic valve/aorta. In addition, ARL67156 normalized the level of pAkt, an important kinase involved in the survival pathway. Inhibition of ectonucleotidase activity prevented the development of calcific aortic valve disease in a rat model. On that account, ectonucleotidase may represent a novel target in the treatment of calcific aortic valve disease.
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Affiliation(s)
- Nancy Côté
- Laboratoire d'Études Moléculaires des Valvulopathies (LEMV), Groupe de Recherche en Valvulopathies (GRV), Quebec Heart and Lung Institute/Research Center, Department of Surgery, Laval University, Quebec, Canada
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Leng H, Zang WQ, Wang T, Wang YY, Ma J, Zhao GQ. Overexpression of miR-451 inhibits cell proliferation and invasion and promotes apoptosis in human esophageal carcinoma cell line EC9706. Shijie Huaren Xiaohua Zazhi 2012; 20:1323-1327. [DOI: 10.11569/wcjd.v20.i15.1323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To explore the effect of overexpression of miR-451 on cell proliferation, apoptosis and invasion in human esophageal carcinoma cell line EC9706.
METHODS: MiR-451 mimics were constructed and transfected into EC9706 cells using LipofectamineTM2000. EC9706 cells transfected with Scramble-miR, empty liposomes or negative miR-451 were used as controls. Forty-eight hours after transfection, the expression of miR-451 was detected by RT-PCR, and the expression of Bcl-2, AKT and phosphorylated AKT proteins were detected by Western blot. Cell apoptosis, invasion and proliferation were assessed by flow cytometry, transwell assay and MTT assay, respectively.
RESULTS: Compared to control cells, the expression of miR-451 was significantly up-regulated (P < 0.01, F = 69.26); the expression of Bcl-2, AKT and phosphorylated AKT proteins was significantly down-regulated (P < 0.05, F = 5.83); cell apoptosis rate significantly increased (P < 0.01, F = 26.72); the average number of cells penetrating Matrigel membrane significantly decreased (P < 0.01, F = 34.55); and cell proliferation was significantly suppressed in a time-dependent manner (P < 0.05, F = 5.95) in EC9706 cells transfected with miR-451 mimics.
CONCLUSION: Over-expression of miR-451 induces apoptosis and suppresses cell proliferation and invasion in human esophageal carcinoma cell line EC9706.
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Mueller A, Bachmann E, Linnig M, Khillimberger K, Schimanski CC, Galle PR, Moehler M. Selective PI3K inhibition by BKM120 and BEZ235 alone or in combination with chemotherapy in wild-type and mutated human gastrointestinal cancer cell lines. Cancer Chemother Pharmacol 2012; 69:1601-15. [PMID: 22543857 DOI: 10.1007/s00280-012-1869-z] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 04/12/2012] [Indexed: 01/09/2023]
Abstract
PURPOSE New targeted agents like antibodies or small molecules against tyrosine and lipid kinases clearly expand the standard therapy options in oncology. However, tumour resistance is still a challenge, often induced by mutations in growth-related signalling cascades. Twenty and ten percentage of all patients with colorectal and gastric cancers, respectively, carry phosphatidyl-3-kinase (PI3K) mutations and do not respond to receptor-blocking therapies. Recently, selective kinase inhibitors have been generated, which block the PI3K signalling pathway in tumour cells. So far, their therapeutic role for the treatment of mutated versus wild-type human gastrointestinal cancers has not been clarified in detail. METHODS To define the inhibitory and pro-apoptotic effects of the two PI3K inhibitors BEZ235 and BKM120 in three human colon cancer (HT-29, HCT-116 and DLD-1) and three gastric cancer (NCI-n87, AGS and MKN-45), cell lines with different PIK3CA gene mutation status were used. Firstly, viability, apoptosis and caspase assays were performed during incubation with either the inhibitors alone or combined with different cytotoxic agents. Secondly, the molecular consequences for the cell cycle and signalling pathways were analysed by defining the protein levels by FACS and Western blot analysis. RESULTS Both the PI3K inhibitors BEZ235 and BKM120 induced a clear concentration-dependent reduction in cell viability and an increase in apoptotic cell death, with the mutated cells being more sensitive to treatment. However, single-agent BEZ235 caused a G1 arrest in tumour cells, whilst BKM120 induced a G2 shift in a half of the gastrointestinal cancer cell lines. There was a clear downregulation in the protein levels of the PI3K-AKT pathway at the concentrations of 100 nM for both agents and for BEZ235 the additional inhibition of the mTOR pathway. Furthermore, BEZ235 caused synergistic induction of apoptosis when combined with irinotecan in colon cancer cell lines. Human gastric cancer cells were less sensitive to both BEZ235 and BKM120. CONCLUSIONS BEZ235 and BKM120 induced pro-apoptotic effects in all cell lines and especially with an increased response in the PI3KCA mutated cells. Our data support the clinical development of these PI3K inhibitors for patients with wild-type or mutated colon cancers.
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Affiliation(s)
- Annett Mueller
- First Department of Internal Medicine, University Medical Centre of the Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55101, Mainz, Germany.
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