51
|
Natriuretic Peptides and Cardiovascular Regulation. Cardiovasc Endocrinol 2008. [DOI: 10.1007/978-1-59745-141-3_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
52
|
Grills C, Crawford N, Chacko A, Johnston PG, O'Rourke F, Fennell DA. Dynamical systems analysis of mitochondrial BAK activation kinetics predicts resistance to BH3 domains. PLoS One 2008; 3:e3038. [PMID: 18725943 PMCID: PMC2516175 DOI: 10.1371/journal.pone.0003038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Accepted: 08/04/2008] [Indexed: 11/23/2022] Open
Abstract
Introduction The molecular mechanism underlying mitochondrial BAK activation during apoptosis remains highly controversial. Two seemingly conflicting models have been proposed. In one, BAK requires so-called activating BH3 only proteins (aBH3) to initiate its conformation change. In the other, displacement from inhibitory pro-survival BCL-2 proteins (PBPs) and monomerization of BAK by PBP selective dissociator BH3-only proteins (dBH3) is sufficient. Methodology/Principal Findings To better understand the kinetic implications of these conflicting but highly evidence-based models, we have conducted a deterministic, dynamical systems analysis to explore the kinetics underlying the first step of BAK activation, as a non-linear reaction system. We show that dBH3 induced BAK activation is efficient, even in the absence of aBH3s, provided constitutive interaction of PBPs with open conformation BAK occurs in an adenoviral E1B 19K-like manner. The pattern of PBP expression robustly predicts the efficacy of dBH3s. Conclusion Our findings accommodate the prevailing BAK activation models as potentially coexisting mechanisms capable of initiating BAK activation, and supports a model based approach for predicting resistance to therapeutically relevant small molecule BH3 mimetics.
Collapse
Affiliation(s)
- Claire Grills
- School of Applied Mathematics and Theoretical Physics, Queens University Belfast, Belfast, Northern Ireland
| | - Nyree Crawford
- Centre for Cancer Research and Cell Biology, Queens University Belfast, Belfast, Northern Ireland
| | - Alex Chacko
- Centre for Cancer Research and Cell Biology, Queens University Belfast, Belfast, Northern Ireland
| | - Patrick G. Johnston
- Centre for Cancer Research and Cell Biology, Queens University Belfast, Belfast, Northern Ireland
- Northern Ireland Cancer Centre, Belfast, Northern Ireland
| | - Francesca O'Rourke
- School of Applied Mathematics and Theoretical Physics, Queens University Belfast, Belfast, Northern Ireland
- Centre for Cancer Research and Cell Biology, Queens University Belfast, Belfast, Northern Ireland
| | - Dean A. Fennell
- Centre for Cancer Research and Cell Biology, Queens University Belfast, Belfast, Northern Ireland
- Northern Ireland Cancer Centre, Belfast, Northern Ireland
- * E-mail:
| |
Collapse
|
53
|
TOMKOVÁ H, FUJIMOTO W, ARATA J. Expression of bcl-2 antagonist bak in inflammatory and neoplastic skin diseases. Br J Dermatol 2008. [DOI: 10.1046/j.1365-2133.1997.19392054.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
54
|
Abstract
It has been almost three decades since the term "apoptosis" was first coined to describe a unique form of cell death that involves orderly, gene-dependent cell disintegration. It is now well accepted that apoptosis is an essential life process for metazoan animals and is critical for the formation and function of tissues and organs. In the adult mammalian body, apoptosis is especially important for proper functioning of the immune system. In recent years, along with the rapid advancement of molecular and cellular biology, great progress has been made in understanding the mechanisms leading to apoptosis. It is generally accepted that there are two major pathways of apoptotic cell death induction: extrinsic signaling through death receptors that leads to the formation of the death-inducing signaling complex (DISC), and intrinsic signaling mainly through mitochondria which leads to the formation of the apoptosome. Formation of the DISC or apoptosome, respectively, activates initiator and common effector caspases that execute the apoptosis process. In the immune system, both pathways operate; however, it is not known whether they are sufficient to maintain lymphocyte homeostasis. Recently, new apoptotic mechanisms including caspase-independent pathways and granzyme-initiated pathways have been shown to exist in lymphocytes. This review will summarize our understanding of the mechanisms that control the homeostasis of various lymphocyte populations.
Collapse
Affiliation(s)
- Guangwu Xu
- Department of Molecular Genetics, Microbiology and Immunology, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854, USA
| | | |
Collapse
|
55
|
Spence P, Franco R, Wood A, Moyer JA. Section Review Central & Peripheral Nervous Systems: Mechanisms of apoptosis as drug targets in the central nervous system. Expert Opin Ther Pat 2008. [DOI: 10.1517/13543776.6.4.345] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
56
|
Torrecillas A, Martínez-Senac MM, Ausili A, Corbalán-García S, Gómez-Fernández JC. Interaction of the C-terminal domain of Bcl-2 family proteins with model membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2007; 1768:2931-9. [PMID: 17905195 DOI: 10.1016/j.bbamem.2007.08.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2007] [Revised: 07/23/2007] [Accepted: 08/13/2007] [Indexed: 11/19/2022]
Abstract
Bcl-2 family proteins are involved in the cell homeostasis by regulating programmed cell death. Some of these proteins promote apoptosis, while others inhibit the same process. The C-terminal hydrophobic domain of some of these proteins is predicted to be involved in anchoring them to a variety of cell membranes, such as mitochondrial, endoplasmic reticulum and nuclear membranes. We have used five synthetic peptides imitating the C-terminal domain from both anti-apoptotic (Bcl-2) and pro-apoptotic members (Bak, Bax, and two mutants of this last protein) of this family to study their interaction with model membranes. Some differences were detected in the interaction with these peptides. The addition of all the peptides to large unilamellar vesicles destabilized them and released encapsulated carboxyfluorescein to different degrees, so that fluidity and the increase in negative curvature favoured the extent in the release of carboxyfluorescein. Bcl-2-C and Bax-C peptides produced the highest release levels in most cases, while BaxS184K-C was the least efficient in this respect. These results indicate that these C-terminal domains are able to insert themselves in the membranes, each in a different way that is probably related with their different way which can be related to their differing locations within the cell and their different roles in regulating apoptosis.
Collapse
Affiliation(s)
- Alejandro Torrecillas
- Departamento de Bioquímica y Biología Molecular (A), Facultad de Veterinaria, Universidad de Murcia, Apartado de Correos 4021, E-30080, Murcia, Spain
| | | | | | | | | |
Collapse
|
57
|
Kim YA, Xiao D, Xiao H, Powolny AA, Lew KL, Reilly ML, Zeng Y, Wang Z, Singh SV. Mitochondria-mediated apoptosis by diallyl trisulfide in human prostate cancer cells is associated with generation of reactive oxygen species and regulated by Bax/Bak. Mol Cancer Ther 2007; 6:1599-609. [PMID: 17513609 PMCID: PMC2805823 DOI: 10.1158/1535-7163.mct-06-0754] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Garlic constituent diallyl trisulfide (DATS) inhibits growth of cancer cells in vitro and in vivo by causing apoptosis, but the sequence of events leading to cell death is not fully understood. We now show that DATS treatment triggers mitochondria-mediated apoptosis program in human prostate cancer cells (LNCaP, LNCaP-C81, LNCaP-C4-2) irrespective of their androgen responsiveness. Interestingly, a normal prostate epithelial cell line (PrEC) is significantly more resistant to apoptosis induction by DATS compared with prostate cancer cells. The DATS-induced apoptosis in LNCaP cells correlated with the collapse of mitochondrial membrane potential, modest increase in protein level of Bak, and down-regulation of Bcl-2 and Bcl-xL protein levels. The DATS-induced apoptosis was significantly attenuated by knockdown of Bax and Bak proteins, but not by ectopic expression of either Bcl-2 or Bcl-xL. The DATS treatment caused generation of reactive oxygen species (ROS) in LNCaP cells, but not in PrEC, which was attenuated by pretreatment with antioxidant N-acetylcysteine. The N-acetylcysteine pretreatment conferred significant protection against DATS-mediated disruption of the mitochondrial membrane potential and apoptosis. In conclusion, the present study reveals that the mitochondria-mediated cell death by DATS is associated with ROS generation and regulated by Bax/Bak but independent of Bcl-2 or Bcl-xL.
Collapse
Affiliation(s)
- Young-Ae Kim
- Department of Pharmacology and Urology, University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
58
|
Abstract
This overview presents curcumin as a significant chemosensitizer in cancer chemotherapy. Although the review focuses on curcumin and its analogues on multidrug resistance (MDR) reversal, the relevance of curcumin as a nuclear factor (NF)-KB blocker and sensitizer of many chemoresistant cancer cell lines to chemotherapeutic agents will also be discussed. One of the major mechanisms of MDR is the enhanced ability of tumor cells to actively efflux drugs, leading to a decrease in cellular drug accumulation below toxic levels. Active drug efflux is mediated by several members of the ATP-binding cassette (ABC) superfamily of membrane transporters, which have now been subdivided into seven families designated A through G. Among these ABC families, the classical MDR is attributed to the elevated expression of ABCB1 (Pgp), ABCC1 (MRP1), and ABCG2 (MXR). The clinical importance of Pgp, MRP1, and MXR for MDR and cancer treatment has led to the investigation of the inhibiting properties of several compounds on these transporters. At present, due in part to the disappointing results associated with the many side effects of synthetic modulators that have been used in clinical trials, current research efforts are directed toward the identification of novel compounds, with attention to dietary natural products. The advantage is that they exhibit little or virtually no side effects and do not further increase the patient's medication burden.
Collapse
MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/antagonists & inhibitors
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- ATP-Binding Cassette Transporters/genetics
- ATP-Binding Cassette Transporters/metabolism
- Animals
- Antineoplastic Agents/metabolism
- Antineoplastic Agents, Phytogenic/metabolism
- Apoptosis/drug effects
- Curcumin/analogs & derivatives
- Curcumin/chemistry
- Curcumin/pharmacology
- Drug Resistance, Multiple/drug effects
- Drug Resistance, Neoplasm/genetics
- Forecasting
- Gene Expression Regulation, Neoplastic
- Humans
- Mitoxantrone/metabolism
- Neoplasms/drug therapy
- Neoplasms/genetics
- Neoplasms/metabolism
- Neoplasms, Experimental/drug therapy
- Neoplasms, Experimental/genetics
- Neoplasms, Experimental/metabolism
Collapse
Affiliation(s)
- Pornngarm Limtrakul
- Department of Biochemistry, Faculty of Medicine, Chiang Mai University, Thailand.
| |
Collapse
|
59
|
Schmitt E, Paquet C, Beauchemin M, Bertrand R. DNA-damage response network at the crossroads of cell-cycle checkpoints, cellular senescence and apoptosis. J Zhejiang Univ Sci B 2007; 8:377-97. [PMID: 17565509 PMCID: PMC1879163 DOI: 10.1631/jzus.2007.b0377] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Tissue homeostasis requires a carefully-orchestrated balance between cell proliferation, cellular senescence and cell death. Cells proliferate through a cell cycle that is tightly regulated by cyclin-dependent kinase activities. Cellular senescence is a safeguard program limiting the proliferative competence of cells in living organisms. Apoptosis eliminates unwanted cells by the coordinated activity of gene products that regulate and effect cell death. The intimate link between the cell cycle, cellular senescence, apoptosis regulation, cancer development and tumor responses to cancer treatment has become eminently apparent. Extensive research on tumor suppressor genes, oncogenes, the cell cycle and apoptosis regulatory genes has revealed how the DNA damage-sensing and -signaling pathways, referred to as the DNA-damage response network, are tied to cell proliferation, cell-cycle arrest, cellular senescence and apoptosis. DNA-damage responses are complex, involving "sensor" proteins that sense the damage, and transmit signals to "transducer" proteins, which, in turn, convey the signals to numerous "effector" proteins implicated in specific cellular pathways, including DNA repair mechanisms, cell-cycle checkpoints, cellular senescence and apoptosis. The Bcl-2 family of proteins stands among the most crucial regulators of apoptosis and performs vital functions in deciding whether a cell will live or die after cancer chemotherapy and irradiation. In addition, several studies have now revealed that members of the Bcl-2 family also interface with the cell cycle, DNA repair/recombination and cellular senescence, effects that are generally distinct from their function in apoptosis. In this review, we report progress in understanding the molecular networks that regulate cell-cycle checkpoints, cellular senescence and apoptosis after DNA damage, and discuss the influence of some Bcl-2 family members on cell-cycle checkpoint regulation.
Collapse
Affiliation(s)
- Estelle Schmitt
- Notre Dame Hospital and Montreal Cancer Institute, Research Centre of University of Montreal Hospital Centre (CRCHUM), Montreal (Que) H2L 4M1, Canada
| | - Claudie Paquet
- Notre Dame Hospital and Montreal Cancer Institute, Research Centre of University of Montreal Hospital Centre (CRCHUM), Montreal (Que) H2L 4M1, Canada
| | - Myriam Beauchemin
- Notre Dame Hospital and Montreal Cancer Institute, Research Centre of University of Montreal Hospital Centre (CRCHUM), Montreal (Que) H2L 4M1, Canada
| | - Richard Bertrand
- Notre Dame Hospital and Montreal Cancer Institute, Research Centre of University of Montreal Hospital Centre (CRCHUM), Montreal (Que) H2L 4M1, Canada
- Medicine Department, University of Montreal, Montreal (Que) H3C 3J7, Canada
- †E-mail:
| |
Collapse
|
60
|
Mehta SL, Manhas N, Raghubir R. Molecular targets in cerebral ischemia for developing novel therapeutics. ACTA ACUST UNITED AC 2007; 54:34-66. [PMID: 17222914 DOI: 10.1016/j.brainresrev.2006.11.003] [Citation(s) in RCA: 532] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Revised: 11/09/2006] [Accepted: 11/10/2006] [Indexed: 11/20/2022]
Abstract
Cerebral ischemia (stroke) triggers a complex series of biochemical and molecular mechanisms that impairs the neurologic functions through breakdown of cellular integrity mediated by excitotoxic glutamatergic signalling, ionic imbalance, free-radical reactions, etc. These intricate processes lead to activation of signalling mechanisms involving calcium/calmodulin-dependent kinases (CaMKs) and mitogen-activated protein kinases (MAPKs) such as extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). The distribution of these transducers bring them in contact with appropriate molecular targets leading to altered gene expression, e.g. ERK and JNK mediated early gene induction, responsible for activation of cell survival/damaging mechanisms. Moreover, inflammatory reactions initiated at the neurovascular interface and alterations in the dynamic communication between the endothelial cells, astrocytes and neurons are thought to substantially contribute to the pathogenesis of the disease. The damaging mechanisms may proceed through rapid nonspecific cell lysis (necrosis) or by active form of cell demise (apoptosis or necroptosis), depending upon the severity and duration of the ischemic insult. A systematic understanding of these molecular mechanisms with prospect of modulating the chain of events leading to cellular survival/damage may help to generate the potential strategies for neuroprotection. This review briefly covers the current status on the molecular mechanisms of stroke pathophysiology with an endeavour to identify potential molecular targets such as targeting postsynaptic density-95 (PSD-95)/N-methyl-d-aspartate (NMDA) receptor interaction, certain key proteins involved in oxidative stress, CaMKs and MAPKs (ERK, p38 and JNK) signalling, inflammation (cytokines, adhesion molecules, etc.) and cell death pathways (caspases, Bcl-2 family proteins, poly (ADP-ribose) polymerase-1 (PARP-1), apoptosis-inducing factor (AIF), inhibitors of apoptosis proteins (IAPs), heat shock protein 70 (HSP70), receptor interacting protein (RIP), etc., besides targeting directly the genes itself. However, selecting promising targets from various signalling cascades, for drug discovery and development is very challenging, nevertheless such novel approaches may lead to the emergence of new avenues for therapeutic intervention in cerebral ischemia.
Collapse
Affiliation(s)
- Suresh L Mehta
- Division of Pharmacology, Central Drug Research Institute, Chatter Manzil Palace, POB-173, Lucknow-226001, India
| | | | | |
Collapse
|
61
|
Seo SK, Lee HC, Woo SH, Jin HO, Yoo DH, Lee SJ, An S, Choe TB, Park MJ, Hong SI, Park IC, Rhee CH. Sulindac-derived reactive oxygen species induce apoptosis of human multiple myeloma cells via p38 mitogen activated protein kinase-induced mitochondrial dysfunction. Apoptosis 2006; 12:195-209. [PMID: 17136320 DOI: 10.1007/s10495-006-0527-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Non-steroidal anti-inflammatory drugs are well known to induce apoptosis of cancer cells independent of their ability to inhibit cyclooxygenase-2, but the molecular mechanism for this effect has not yet been fully elucidated. The purpose of this study was to elucidate the potential signaling components underlying sulindac-induced apoptosis in human multiple myeloma (MM) cells. We found that sulindac induces apoptosis by promoting ROS generation, accompanied by opening of mitochondrial permeability transition pores, release of cytochrome c and apoptosis inducing factor from mitochondria, followed by caspase activation. Bcl-2 cleavage and down-regulation of the inhibitor of apoptosis proteins (IAPs) family including cIAP-1/2, XIAP, and survivin, occurred downstream of ROS production during sulindac-induced apoptosis. Forced expression of survivin and Bcl-2 blocked sulindac-induced apoptosis. Most importantly, sulindac-derived ROS activated p38 mitogen-activated protein kinase and p53. SB203580, a p38 mitogen-activated protein kinase inhibitor, and RNA inhibition of p53 inhibited the sulindac-induced apoptosis. Furthermore, p53, Bax, and Bak accumulated in mitochondria during sulindac-induced apoptosis. All of these events were significantly suppressed by SB203580. Our results demonstrate a novel mechanism of sulindac-induced apoptosis in human MM cells, namely, accumulation of p53, Bax, and Bak in mitochondria mediated by p38 MAPK activation downstream of ROS production.
Collapse
Affiliation(s)
- Sung-Keum Seo
- Laboratory of Functional Genomics, Korea Institute of Radiological & Medical Sciences, 215-4 Gongneung-Dong, Nowon-Ku, Seoul, 139-706, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
62
|
Xiao D, Lew KL, Kim YA, Zeng Y, Hahm ER, Dhir R, Singh SV. Diallyl trisulfide suppresses growth of PC-3 human prostate cancer xenograft in vivo in association with Bax and Bak induction. Clin Cancer Res 2006; 12:6836-43. [PMID: 17121905 DOI: 10.1158/1078-0432.ccr-06-1273] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE The present study was undertaken to determine the effect of garlic constituent diallyl trisulfide (DATS) on growth of PC-3 human prostate cancer xenograft in vivo. EXPERIMENTAL DESIGN DATS was given orally (6 micromoL, thrice weekly) to male athymic mice s.c. implanted with PC-3 cells. Tumor sections from control and DATS-treated mice were examined for apoptotic bodies by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. Protein levels of apoptosis and cell cycle regulating proteins in tumor tissues of control and DATS-treated mice were determined by immunoblotting. The effect of DATS treatment on in vivo angiogenesis was determined by immunohistochemical analysis of CD31 in tumors. RESULTS Oral gavage of DATS significantly retarded growth of PC-3 xenografts in athymic mice without causing weight loss. For instance, 20 days after starting therapy, the average tumor volume in control mice was approximately 3-fold higher compared with DATS-treated mice. Tumors from DATS-treated mice exhibited a markedly higher count of apoptotic bodies compared with control tumors. Consistent with the results in cultured PC-3 cells, the DATS-mediated suppression of PC-3 xenograft growth correlated with induction of proapoptotic proteins Bax and Bak. Although DATS treatment inhibited migration of cultured PC-3 cells in association with down-regulation of vascular endothelial growth factor receptor-2 protein, formation of new blood vessels was comparable in tumors of control and DATS-treated mice as judged by CD31 immunostaining. CONCLUSIONS The present study indicates that DATS administration inhibits growth of PC-3 xenografts in vivo in association with induction of Bax and Bak.
Collapse
Affiliation(s)
- Dong Xiao
- Department of Pharmacology and University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15213, USA
| | | | | | | | | | | | | |
Collapse
|
63
|
Lu Y, Xu YB, Yuan TT, Song MG, Lübbert M, Fliegauf M, Chen GQ. Inducible expression of AML1-ETO fusion protein endows leukemic cells with susceptibility to extrinsic and intrinsic apoptosis. Leukemia 2006; 20:987-93. [PMID: 16598301 DOI: 10.1038/sj.leu.2404218] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
AML1-ETO, a leukemia-associated fusion protein generated by the frequently occurred chromosome translocation t(8;21) in acute myeloid leukemia, was shown to exert dichotomous functions in leukemic cells, that is, growth arrest versus differentiation block. By the analysis of oligonucleotide microarray, AML1-ETO was shown to modulate the expressions of an impressive array of pro- and anti-apoptotic genes. Here, we investigate potential effects of the ecdysone inducible AML1-ETO expression on apoptosis of leukemic U937 cell line. We show that AML1-ETO significantly stabilizes death receptor Fas protein and increases proapoptotic Bak in addition to reducing Bcl-2 expression. Accordingly, inducible AML1-ETO expression is followed by apoptosis to a lower degree. Especially, AML1-ETO endows leukemic cells with the susceptibility to anti-Fas agonist antibody, ultraviolet light and camptothecin analog NSC606985-induced apoptosis with increased activation of caspase-3/8. Considering that apoptosis-enhancing effect of AML1-ETO would not be favorable to the leukemogenesis harboring the t(8;21) translocation, it must be overcome to fulfill their leukemogenic potential. Complementary to this prediction is that two AML1-ETO-carrying leukemic cells, Kasumi-1 and SKNO-1, present similar sensitivity to apoptosis induction with AML1-ETO-negative leukemic cells. Therefore, genetic and/or epigenetic screenings of apoptosis-related genes modulated by AML1-ETO deserve to be explored for understanding the mechanisms of AML1-ETO-induced leukemogenesis.
Collapse
Affiliation(s)
- Y Lu
- The Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Rui-Jin Hospital, Shanghai Jiao-Tong University School of Medicine, Shanghai, China
| | | | | | | | | | | | | |
Collapse
|
64
|
Lim SF, Chuan KH, Liu S, Loh SOH, Chung BYF, Ong CC, Song Z. RNAi suppression of Bax and Bak enhances viability in fed-batch cultures of CHO cells. Metab Eng 2006; 8:509-22. [PMID: 16860584 DOI: 10.1016/j.ymben.2006.05.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Revised: 05/11/2006] [Accepted: 05/31/2006] [Indexed: 11/17/2022]
Abstract
Bcl-2 family proteins play a crucial role in the regulation of the mitochondrial pathway that leads to apoptosis. Members of the Bcl-2 family can be divided into the anti-apoptotic proteins such as Bcl-2 and Bcl-X(L), and the pro-apoptotic proteins such as Bax and Bak and the BH3-only proteins. In this study, siRNA constructs to silence the Bax and Bak genes in Chinese hamster ovary (CHO) cells were generated. Stable CHO cell lines in which the expression of Bax and Bak were significantly knocked down were screened by Western blot analysis and confirmed by RT-PCR. CHO cells with both Bax and Bak knocked down showed a clear resistance against cytotoxic lectins and UV irradiation-induced apoptosis. Compared to original CHO-K1 cells, these cells also survived longer when cultured under extreme conditions such as complete nutrient depletion or in high-osmolality medium. CHO cells with both Bax and Bak genes knocked down displayed an extended lifespan as well as higher viable cell densities in fed-batch cultures, both in adherent form on microcarrier beads and in suspension. The IFN-gamma productivity by a rCHO IFN-gamma cell line in which both Bak and Bax were knocked down increased by 35% compared to the control cells. These results indicate that the genetic inactivation of Bax and Bak in recombinant CHO cells can be an effective strategy in delaying the onset of apoptosis in batch and fed-batch cultures.
Collapse
Affiliation(s)
- Sing Fee Lim
- Bioprocessing Technology Institute, Agency for Science, Technology and Research, 20 Biopolis Way, 06-01 Centros, Singapore 138668, Singapore
| | | | | | | | | | | | | |
Collapse
|
65
|
Thomadaki H, Scorilas A. BCL2 family of apoptosis-related genes: functions and clinical implications in cancer. Crit Rev Clin Lab Sci 2006; 43:1-67. [PMID: 16531274 DOI: 10.1080/10408360500295626] [Citation(s) in RCA: 174] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
One of the most effective ways to combat different types of cancer is through early diagnosis and administration of effective treatment, followed by efficient monitoring that will allow physicians to detect relapsing disease and treat it at the earliest possible time. Apoptosis, a normal physiological form of cell death, is critically involved in the regulation of cellular homeostasis. Dysregulation of programmed cell death mechanisms plays an important role in the pathogenesis and progression of cancer as well as in the responses of tumours to therapeutic interventions. Many members of the BCL2 (B-cell CLL/lymphoma 2; Bcl-2) family of apoptosis-related genes have been found to be differentially expressed in various malignancies, and some are useful prognostic cancer biomarkers. We have recently cloned a new member of this family, BCL2L12, which was found to be differentially expressed in many tumours. Most of the BCL2 family genes have been found to play a central regulatory role in apoptosis induction. Results have made it clear that a number of coordinating alterations in the BCL2 family of genes must occur to inhibit apoptosis and provoke carcinogenesis in a wide variety of cancers. However, more research is required to increase our understanding of the extent to which and the mechanisms by which they are involved in cancer development, providing the basis for earlier and more accurate cancer diagnosis, prognosis and therapeutic intervention that targets the apoptosis pathways. In the present review, we describe current knowledge of the function and molecular characteristics of a series of classic but also newly discovered genes of the BCL2 family as well as their implications in cancer development, prognosis and treatment.
Collapse
Affiliation(s)
- Hellinida Thomadaki
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Athens, Panepistimiopolis, 15701 Athens, Greece
| | | |
Collapse
|
66
|
White E. Mechanisms of apoptosis regulation by viral oncogenes in infection and tumorigenesis. Cell Death Differ 2006; 13:1371-7. [PMID: 16676007 DOI: 10.1038/sj.cdd.4401941] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Apoptosis mediated by the proapoptotic BCL-2 family members BCL-2-associated X-protein (BAX) and BCL-2 antagonist/killer (BAK) is part of the antiviral response at the cellular level to limit virus replication. Viruses, in turn, have evolved to encode antiapoptotic BCL-2 homologs (v-BCL-2s) to prevent the premature death of the infected host cell to sustain virus replication. These same v-BCL-2 proteins cooperate with loss of retinoblastoma protein and p53 tumor suppressor function, by inactivating the BAX and BAK apoptotic pathway to promote epithelial solid tumor growth and resistance to chemotherapy. Analogously to infected cells, failure of apoptosis in tumors permits the survival of abnormal, damaged cells displaying chromosome instability that may further promote tumor progression. Thus, both infected cells and tumor cells require inhibition of the apoptotic host defense mechanism, the insights from which can be exploited for therapy development.
Collapse
Affiliation(s)
- E White
- Department of Molecular Biology and Biochemistry, Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ 08854, USA.
| |
Collapse
|
67
|
Takebe N, Cheng X, Fandy TE, Srivastava RK, Wu S, Shankar S, Bauer K, Shaughnessy J, Tricot G. IMP dehydrogenase inhibitor mycophenolate mofetil induces caspase-dependent apoptosis and cell cycle inhibition in multiple myeloma cells. Mol Cancer Ther 2006; 5:457-66. [PMID: 16505121 DOI: 10.1158/1535-7163.mct-05-0340] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Multiple myeloma is an incurable disease for the majority of patients, therefore requiring new biological targeted therapies. In primary myeloma cells, IMP dehydrogenase (IMPDH) was shown to be consistently overexpressed. We therefore tested the IMPDH inhibitor mycophenolate mofetil (MMF) currently available as a clinical therapeutic agent for its antimyeloma activity in vitro. MMF depleted intracellular guanosine 5'-triphosphate (GTP) levels in myeloma cells. We showed apoptosis induction in myeloma cell lines and primary myeloma cells between 1 and 5 mumol/L MMF. MMF was also cytotoxic at this concentration in dexamethasone-resistant and Mcl-1-overexpressed myeloma cell lines shown by the tetrazolium salt XTT assay along with cell survival measured by a modified flow cytometric assay. Apoptosis was not inhibited by the presence of an antioxidant, suggesting that MMF-induced apoptosis is less likely to be associated with reactive oxygen species. However, apoptosis was abrogated by exogenously added guanosine, which activates an alternative pathway for GTP formation, implicating that this effect is directly mediated by IMPDH inhibition. MMF-induced G1-S phase cell cycle arrest and its apoptosis induction mechanism were associated with a caspase-dependent pathway as shown by alteration of mitochondrial membrane potential and cytochrome c release followed by activation of the caspases. MMF-induced apoptosis was also inhibited by a pan-caspase inhibitor Z-VAD-fmk. MMF-treated myeloma cells showed an up-regulation of Bak, which most likely together with Bax resulted in the release of cytochrome c. In summary, MMF attenuates G1-S phase cell cycle progression and activates the pathway of mitochondrial dysfunction, leading to cytochrome c release followed by activation of caspases.
Collapse
Affiliation(s)
- Naoko Takebe
- University of Maryland Greenebaum Cancer Center, 655 West Baltimore Street, BRB 7-029, Baltimore, MD 21201, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
68
|
Wiens M, Belikov SI, Kaluzhnaya OV, Schröder HC, Hamer B, Perovic-Ottstadt S, Borejko A, Luthringer B, Müller IM, Müller WEG. Axial (apical-basal) expression of pro-apoptotic and pro-survival genes in the lake baikal demosponge Lubomirskia baicalensis. DNA Cell Biol 2006; 25:152-64. [PMID: 16569194 DOI: 10.1089/dna.2006.25.152] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Like in all other Metazoa, also in sponges (Porifera) proliferation, differentiation, and death of cells are controlled by apoptotic processes, thus allowing the establishment of a Bauplan (body plan). The demosponge Lubomirskia baicalensis from the Lake Baikal is especially suitable to assess the role of the apoptotic molecules, since its grade of construction is highly elaborated into an encrusting base and branches composed of modules lined up along the apical-basal axis. The four cDNAs, ALG-2, BAK, MA-3, and Bcl-2, were isolated from this sponge species. The expression levels of these genes follow characteristic gradients. While the proapoptotic genes are highly expressed at the base of the branches and comparably low at the top, the pro-survival gene follows an opposite gradient. Parallel with the tuned expression of these genes, the activities of the apoptosis-executing enzymes caspase-8 (IETDase activity) and caspase-3 (DEVDase activity) are lowest at the top of the branch and highest at their base. This characteristic expression/activity pattern of the genes/enzymes, which had been determined in a few specimens, collected from an unpolluted, natural site, appears reversed in specimens collected from an anthropogenically polluted site. These findings indicate the involvement of apoptotic proteins in the axis formation (branches) in L. baicalensis.
Collapse
Affiliation(s)
- Matthias Wiens
- Institut für Physiologische Chemie, Abteilung Angewandte Molekularbiologie, Universität Mainz, Mainz, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
69
|
Singh SV, Zeng Y, Xiao D, Vogel VG, Nelson JB, Dhir R, Tripathi YB. Caspase-dependent apoptosis induction by guggulsterone, a constituent of Ayurvedic medicinal plant Commiphora mukul, in PC-3 human prostate cancer cells is mediated by Bax and Bak. Mol Cancer Ther 2006; 4:1747-54. [PMID: 16275996 DOI: 10.1158/1535-7163.mct-05-0223] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The present study was undertaken to gain insights into the molecular mechanism of cell death (apoptosis) by guggulsterone, a constituent of Ayurvedic medicinal plant Commiphora mukul, using PC-3 human prostate cancer cells as a model. The viability of PC-3 cells, but not a normal prostate epithelial cell line (PrEC), was reduced significantly on treatment with guggulsterone in a concentration-dependent manner. Guggulsterone-mediated suppression of PC-3 cell proliferation was not due to perturbation in cell cycle progression but caused by apoptosis induction characterized by appearance of subdiploid cells and cytoplasmic histone-associated DNA fragmentation. Guggulsterone-induced apoptosis was associated with induction of multidomain proapoptotic Bcl-2 family members Bax and Bak. Interestingly, the expression of antiapoptotic proteins Bcl-2 and Bcl-xL was initially increased in guggulsterone-treated PC-3 cells but declined markedly following a 16- to 24-hour treatment with guggulsterone. Ectopic expression of Bcl-2 in PC-3 cells failed to confer significant protection against guggulsterone-induced cell death. On the other hand, SV40 immortalized mouse embryonic fibroblasts derived from Bax-Bak double knockout mice were significantly more resistant to guggulsterone-induced cell killing compared with wild-type cells. Guggulsterone treatment resulted in cleavage (activation) of caspase-9, caspase-8, and caspase-3, and guggulsterone-induced cell death was significantly attenuated in the presence of general caspase inhibitor as well as specific inhibitors of caspase-9 and caspase-8. In conclusion, the present study indicates that caspase-dependent apoptosis by guggulsterone is mediated in part by Bax and Bak.
Collapse
Affiliation(s)
- Shivendra V Singh
- Department of Pharmacology and University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, 2.32A Hillman Cancer Center Research Pavilion, 5117 Centre Avenue, Pittsburgh, Pennsylvania 15213, USA.
| | | | | | | | | | | | | |
Collapse
|
70
|
Landgraeber S, Toetsch M, Wedemeyer C, Saxler G, Tsokos M, von Knoch F, Neuhäuser M, Löer F, von Knoch M. Over-expression of p53/BAK in aseptic loosening after total hip replacement. Biomaterials 2006; 27:3010-20. [PMID: 16445975 DOI: 10.1016/j.biomaterials.2006.01.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2005] [Accepted: 01/06/2006] [Indexed: 11/29/2022]
Abstract
Particle-induced osteolysis is a major cause of aseptic loosening after total joint replacement. The possible induction of apoptosis has not been addressed in great detail. Thus far, it has been shown that ceramic and polyethylene particles can induce apoptosis of macrophages in vitro. The purpose of this study was to test the hypothesis that wears debris generated from total hip arthroplasty could induce cellular damage and apoptosis in vivo. We therefore determined by immunohistochemical methods if increased expression of p53, an important transcription factor, and BAK and Bcl-2, two important regulators of apoptosis, can be found in interface membranes and capsules of hips with aseptically loose implants. Strongly positive immunohistochemical staining for p53 and BAK was found in peri-implant tissues from patients with aseptic hip implant loosening. Differentiation of various cell types showed that macrophages stained positive for p53 in all capsule and interface specimens. p53 was frequently detected in giant cells. Positive staining of BAK in macrophages and giant cells was seen in all specimens. Some positive reactions were observed in fibroblasts, only two of 19 cases stained for p53 and three cases for BAK within synovial cells. Positive macrophages and giant cells were localized around polyethylene particles. While T-lymphocytes showed a regular BAK-staining, the other leukocytes were negative. Statistical analyses showed significant positive correlations (p < 0.001) between the presence of polyethylene and metal debris and the expression of BAK and p53. Polyethylene particles were surrounded by more positive macrophages and giant cells than were metal particles, indicating that polyethylene debris may be a stronger inductor of cell cycle arrest and apoptosis than metal debris. In this study apoptosis of macrophages, giant cells and T-lymphocytes in capsules and interface membranes of patients with aseptic hip implant loosening has been demonstrated in vivo. It is possible that the apoptotic cascade could evolve as a novel therapeutic target to prevent particle-induced osteolysis.
Collapse
Affiliation(s)
- Stefan Landgraeber
- Department of Orthopaedics, University of Duisburg-Essen, Pattbergstrasse 1-3, 45239 Essen, Germany.
| | | | | | | | | | | | | | | | | |
Collapse
|
71
|
Yang WS, Ko JK, Park SO, Choi HY, Kim YN, Kim CW. C-terminal region of Bfl-1 induces cell death that accompanies caspase activation when fused with GFP. J Cell Biochem 2005; 94:1234-47. [PMID: 15696550 DOI: 10.1002/jcb.20381] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Previously, we reported that anti-apoptotic Bfl-1 is converted to a pro-apoptotic protein following fusion at its N-terminus with green fluorescent protein (GFP) (GFP-Bfl-1). In this study, we performed a Bfl-1 deletion study in order to elucidate the underlying mechanism of GFP-Bfl-1-induced cell death. We found that the Bcl-2 homology (BH) domains in Bfl-1 are dispensable with respect to cell death and that GFP fusion with the 29 amino acids of the C-terminal region of Bfl-1 (GFP-BC) is sufficient to induce cell death. Moreover, when BC was fused with other tagging partners like GST or MBP, little cell death was observed, implying that the GFP region is as important as the BC region for GFP-BC-induced cell death. Further deletion analysis defined a region of GFP as a determinant of GFP-BC-induced cell death. Confocal microscopic analysis showed that GFP-chimeras containing the BC region of Bfl-1 are located mainly in mitochondria. The GFP-BC-induced cell death accompanied cellular caspase activation, and treatment with the pan-caspase inhibitor, Boc-D-FMK, partially inhibited GFP-BC-induced cell death. However, the over-expression of anti-apoptotic molecules, such as Bcl-x(L) and CrmA, did not block GFP-BC-induced cell death. In summary, GFP-BC induces cell death with caspase activation through mitochondria dependent process.
Collapse
Affiliation(s)
- Wan Seok Yang
- Department of Pathology, Tumor Immunity Medical Research Center and Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | | | | | | | | | | |
Collapse
|
72
|
Fayad R, Sennello JA, Kim SH, Pini M, Dinarello CA, Fantuzzi G. Induction of thymocyte apoptosis by systemic administration of concanavalin A in mice: role of TNF-alpha, IFN-gamma and glucocorticoids. Eur J Immunol 2005; 35:2304-12. [PMID: 16047339 DOI: 10.1002/eji.200526062] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Administration of concanavalin A (Con A) is a well-established model of acute immune-mediated hepatitis. Here, we demonstrate that intravenous injection of Con A in mice induces profound thymic atrophy. Compared to liver damage, the kinetics of Con A-induced thymic atrophy is slower and more prolonged; the nadir in thymocyte number is reached 4 days after Con A injection, whereas peak transaminase levels are observed at 12-24 h. Marked alterations in the ratio of CD4+ and CD8+cells in the thymus and spleen and significantly increased rates of thymocyte and splenocyte apoptosis are observed. Neutralization of the cytokines TNF-alpha or IFN-gamma, which protects mice from Con A-induced hepatitis, prevents thymic atrophy as well as alterations in CD4+ and CD8+ cell numbers and apoptosis rates. However, neither TNF-alpha nor IFN-gamma are detectable in thymocyte lysates after Con A injection, whereas both cytokines are present in liver, spleen and serum. Administration of the glucocorticoid receptor antagonist mifepristone does not prevent thymic atrophy, thus ruling out a possible contribution of endogenous glucocorticoids. Con A-induced thymic atrophy is accompanied by down-regulation of Bcl-2 expression in the thymus, which is prevented by neutralization of TNF-alpha or IFN-gamma. These data demonstrate that the thymus is a critical target organ of Con A-induced inflammation; the effects of Con A on the thymus are mediated by extrathymic production of TNF-alpha and IFN-gamma, but not by glucocorticoids.
Collapse
Affiliation(s)
- Raja Fayad
- Department of Human Nutrition, University of Illinois at Chicago, Chicago, IL 60612, USA
| | | | | | | | | | | |
Collapse
|
73
|
Zhang N, Hartig H, Dzhagalov I, Draper D, He YW. The role of apoptosis in the development and function of T lymphocytes. Cell Res 2005; 15:749-69. [PMID: 16246265 DOI: 10.1038/sj.cr.7290345] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Apoptosis plays an essential role in T cell biology. Thymocytes expressing nonfunctional or autoreactive TCRs are eliminated by apoptosis during development. Apoptosis also leads to the deletion of expanded effector T cells during immune responses. The dysregulation of apoptosis in the immune system results in autoimmunity, tumorogenesis and immunodeficiency. Two major pathways lead to apoptosis: the intrinsic cell death pathway controlled by Bcl-2 family members and the extrinsic cell death pathway controlled by death receptor signaling. These two pathways work together to regulate T lymphocyte development and function.
Collapse
Affiliation(s)
- Nu Zhang
- Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
| | | | | | | | | |
Collapse
|
74
|
Roucou X, Giannopoulos PN, Zhang Y, Jodoin J, Goodyer CG, LeBlanc A. Cellular prion protein inhibits proapoptotic Bax conformational change in human neurons and in breast carcinoma MCF-7 cells. Cell Death Differ 2005; 12:783-95. [PMID: 15846375 DOI: 10.1038/sj.cdd.4401629] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Prion protein (PrP) prevents Bcl-2-associated protein X (Bax)-mediated cell death, but the step at which PrP inhibits is not known. We first show that PrP is very specific for Bax and cannot prevent Bak (Bcl-2 antagonist killer 1)-, tBid-, staurosporine- or thapsigargin-mediated cell death. As Bax activation involves Bax conformational change, mitochondrial translocation, cytochrome c release and caspase activation, we investigated which of these events was inhibited by PrP. PrP inhibits Bax conformational change, cytochrome c release and cell death in human primary neurons and MCF-7 cells. Serum deprivation-induced Bax conformational change is more rapid in PrP-null cells. PrP does not prevent active caspase-mediated cell death. PrP does not colocalize with Bax in normal or apoptotic primary neurons and cannot prevent Bax-mediated cytochrome c release in a mitochondrial cell-free system. We conclude that PrP protects against Bax-mediated cell death by preventing the Bax proapoptotic conformational change that occurs initially in Bax activation.
Collapse
Affiliation(s)
- X Roucou
- The Bloomfield Center for Research in Aging, Lady Davis Institute for Medical Research, The Sir Mortimer B Davis Jewish General Hospital, Montréal, Québec, Canada
| | | | | | | | | | | |
Collapse
|
75
|
Xiao D, Zeng Y, Choi S, Lew KL, Nelson JB, Singh SV. Caspase-dependent apoptosis induction by phenethyl isothiocyanate, a cruciferous vegetable-derived cancer chemopreventive agent, is mediated by Bak and Bax. Clin Cancer Res 2005; 11:2670-9. [PMID: 15814648 DOI: 10.1158/1078-0432.ccr-04-1545] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE The present study was undertaken to gain insights into the molecular mechanism of apoptosis induction by phenethyl isothiocyanate (PEITC) using prostate cancer cell lines derived from transgenic adenocarcinoma mouse prostate (TRAMP) mice (TRAMP-C1 and TRAMP-C2). EXPERIMENTAL DESIGN AND RESULTS The viability of TRAMP-C1 and TRAMP-C2 cells was reduced significantly in the presence of PEITC in a concentration-dependent manner as determined by sulforhodamine B and trypan blue dye exclusion assays. Treatment of TRAMP-derived cells with PEITC revealed features characteristic of apoptosis induction, including appearance of subdiploid cells (determined by flow cytometry), cytoplasmic histone-associated DNA fragmentation (determined by an ELISA assay), and cleavage of caspase-3 (determined by immunoblotting). The PEITC-induced apoptosis in TRAMP-derived cells was associated with a marked increase in the level of proapoptotic protein Bak and/or a decrease in the levels of antiapoptotic protein Mcl-1 or Bcl-xL and disruption of mitochondrial membrane potential. The SV40 immortalized mouse embryonic fibroblasts derived from Bak and Bax double knockout mice were significantly more resistant to PEITC-induced DNA fragmentation compared with wild-type or Bak-/- mouse embryonic fibroblasts. The PEITC-induced apoptosis in both cell lines was significantly attenuated in the presence of caspase inhibitors zVAD-fmk, zLEHD-fmk, and zIETD-fmk. Oral administration of PEITC (9 or 12 micromol PEITC/d, Monday-Friday) significantly retarded growth of TRAMP-C1 xenografts in nude mice without causing weight loss or any other side effects. CONCLUSION The results of the present study indicate that caspase-dependent apoptosis by PEITC is mediated by Bak and Bax proteins.
Collapse
Affiliation(s)
- Dong Xiao
- Department of Pharmacology, University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
| | | | | | | | | | | |
Collapse
|
76
|
Abstract
Increasing evidence suggests that natriuretic peptides (NPs) play diverse roles in mammals, including renal hemodynamics, neuroendocrine, and cardiovascular functions. Collectively, NPs are classified as hypotensive hormones; the main actions of NPs are implicated in eliciting natriuretic, diuretic, steroidogenic, antiproliferative, and vasorelaxant effects, important factors in the control of body fluid volume and blood pressure homeostasis. One of the principal loci involved in the regulatory actions of NPs is their cognate plasma membrane receptor molecules, which are activated by binding with specific NPs. Interaction of NPs with their receptors plays a central role in physiology and pathophysiology of hypertension and cardiovascular disorders. Gaining insight into the intricacies of NPs-specific receptor signaling pathways is of pivotal importance for understanding both hormone-receptor biology and the disease states arising from abnormal hormone receptor interplay. During the last decade there has been a surge in interest in NP receptors; consequently, a wealth of information has emerged concerning molecular structure and function, signaling mechanisms, and use of transgenics and gene-targeted mouse models. The objective of this present review is to summarize and document the previous findings and recent discoveries in the field of the natriuretic peptide hormone family and receptor systems with emphasis on the structure-function relationship, signaling mechanisms, and the physiological and pathophysiological significance in health and disease.
Collapse
Affiliation(s)
- Kailash N Pandey
- Department of Physiology, Tulane University Health Sciences Center and School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, USA.
| |
Collapse
|
77
|
Abstract
Apoptosis has been causally linked to the pathogenesis of myocardial infarction and heart failure in rodent models. This death process is mediated by two central pathways, an extrinsic pathway involving cell surface receptors and an intrinsic pathway using mitochondria and the endoplasmic reticulum. Each of these pathways has been implicated in myocardial pathology. In this review, we summarize recent advances in the understanding of the intrinsic pathway and how it relates to cardiac myocyte death and heart disease.
Collapse
Affiliation(s)
- Michael T Crow
- Department of Medicine, Johns Hopkins University School of Medicine, 5501 Hopkins Bayview Circle, Rm 5A.58, Baltimore, MD 21224, USA.
| | | | | | | |
Collapse
|
78
|
Abstract
Apoptosis is a genetically programmed cell death mechanism that appears to occur in all multicellular organisms. It is a normal process that serves to maintain cellular homeostasis. However, in many diseases there is a disruption in the equilibrium between cell proliferation and cell death that contributes directly to the disease. In these cases, a possible therapeutic intervention would be to restore the skewed equilibrium by pushing it in the desired direction through the use of pharmacological agents or genetic approaches. These observations have instigated substantial research in the field of apoptosis, resulting in an increasingly detailed analysis of the molecular mechanisms and the sequence of events that occur in this cell death pathway. In addition, by trying to understand this pathway, several potential therapeutic agents have arisen from those used in chemo-, radio-, and cytokine therapy. While these agents have been relatively successful, it is rare that their effect is complete. Thus, the search continues for a strategy to conquer those cells that are resistant to these regimens. Genetic approaches are novel and have been shown to be quite successful in several in vitro and animal models. They also tend to have low toxicity. It is believed that using a more traditional front-line approach of therapy, supplemented by appropriate genetic intervention, will allow substantial increases in the efficacy of treatment, while at the same time introducing little or no additional toxicity.
Collapse
Affiliation(s)
- S C Dixon
- Medicine Branch, Clinical Pharmacokinetics Unit, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| | | |
Collapse
|
79
|
Uo T, Kinoshita Y, Morrison RS. Neurons exclusively express N-Bak, a BH3 domain-only Bak isoform that promotes neuronal apoptosis. J Biol Chem 2004; 280:9065-73. [PMID: 15590665 DOI: 10.1074/jbc.m413030200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bak is generally recognized as a multidomain, pro-apoptotic member of the Bcl-2 family. Bak and Bax are functionally redundant in non-neuronal cells and represent a mitochondrial convergence point for cell death signaling pathways. This functional redundancy, however, may not exist in neurons in which the single deletion of Bax is sufficient to confer protection against a variety of cytotoxic insults. In the present study, we demonstrate that postnatal cortical and cerebellar granule neurons exclusively express an alternatively spliced, BH3 domain-only form of Bak (N-Bak), whereas astrocytes express only the full-length, multidomain form. Overexpression of N-Bak promotes Bax translocation in HeLa cells and induces neuronal cell death in cortical, hippocampal, and cerebellar granule neurons in a Bax-dependent manner. N-Bak interacts with Bcl-XL but not BAX, suggesting an indirect mechanism for promoting Bax translocation to the mitochondria. N-Bak message and protein levels are elevated in cortical neurons in response to DNA damage, and subsequent induction of neuronal death is significantly delayed by expressing a full-length Bak antisense plasmid. These results demonstrate that postnatal neurons solely express a BH3 domain-only form of Bak, which contributes to DNA damage-induced neuronal apoptosis. The absence of full-length Bak expression explains the near exclusive requirement for Bax in neuronal apoptosis.
Collapse
Affiliation(s)
- Takuma Uo
- Department of Neurological Surgery, University of Washington School of Medicine, Box 356470, Seattle, Washington 98195-6470, USA
| | | | | |
Collapse
|
80
|
Heiser D, Labi V, Erlacher M, Villunger A. The Bcl-2 protein family and its role in the development of neoplastic disease. Exp Gerontol 2004; 39:1125-35. [PMID: 15288687 DOI: 10.1016/j.exger.2004.04.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2004] [Revised: 04/28/2004] [Accepted: 04/30/2004] [Indexed: 01/09/2023]
Abstract
Programmed cell death is the physiological process responsible for shaping organs during embryogenesis, maintaining tissue homeostasis and allowing controlled deletion of potentially harmful cells within the adult organism. The genetics of apoptosis are well conserved in all metazoans and although the evolution of humans and worms separated more than 600 million years ago, basic signaling concepts in apoptosis are highly related in both species. More crucial to humans than worms is the fact that abnormalities in cell death control can contribute to the development of cancer. While C.elegans can easily survive with additional somatic cells that should normally be deleted during development humans may suffer pathological consequences, ranging from tumorigenesis to autoimmunity, as a result of mutations in cell death regulatory genes. Despite the high degree of evolutionary conservation in cell death control, apoptosis signaling in mammals is much more complex than in C.elegans. In mammalian cells, programmed cell death can be induced either by ligand-mediated activation of certain members of the tumor necrosis factor receptor family--so-called 'death receptors'--such as Fas (CD95/Apo-1) and TRAIL or it can be induced in a cell autonomous manner in response to certain stress signals by pro-apoptotic members of the Bcl-2 family. In this review, we focus on general concepts of how the Bcl-2 protein family regulates cell death and how deregulation of this 'intrinsic' apoptotic signaling pathway impinges on the pathogenesis of malignant disease, the major cause of death in the aging population.
Collapse
Affiliation(s)
- Dietmar Heiser
- Institute of Pathophysiology, University of Innsbruck Medical School, Fritz-Pregl-Str. 3, A-6020 Innsbruck, Austria
| | | | | | | |
Collapse
|
81
|
Tong QS, Zheng LD, Wang L, Liu J, Qian W. BAK overexpression mediates p53-independent apoptosis inducing effects on human gastric cancer cells. BMC Cancer 2004; 4:33. [PMID: 15248898 PMCID: PMC481072 DOI: 10.1186/1471-2407-4-33] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2004] [Accepted: 07/12/2004] [Indexed: 11/28/2022] Open
Abstract
Background BAK (Bcl-2 homologous antagonist/killer) is a novel pro-apoptotic gene of the Bcl-2 family. It has been reported that gastric tumors have reduced BAK levels when compared with the normal mucosa. Moreover, mutations of the BAK gene have been identified in human gastrointestinal cancers, suggesting that a perturbation of BAK-mediated apoptosis may contribute to the pathogenesis of gastric cancer. In this study, we explored the therapeutic effects of gene transfer mediated elevations in BAK expression on human gastric cancer cells in vitro. Methods Eukaryotic expression vector for the BAK gene was constructed and transferred into gastric cancer cell lines, MKN-45 (wild-type p53) and MKN-28 (mutant-type p53). RT-PCR and Western Blotting detected cellular BAK gene expression. Cell growth activities were detected by MTT colorimetry and flow cytometry, while apoptosis was assayed by electronic microscopy and TUNEL. Western Blotting and colorimetry investigated cellular caspase-3 activities. Results BAK gene transfer could result in significant BAK overexpression, decreased in vitro growth, cell cycle G0/G1 arrest, and induced apoptosis in gastric cancer cells. In transferred cells, inactive caspase-3 precursor was cleaved into the active subunits p20 and p17, during BAK overexpression-induced apoptosis. In addition, this process occurred equally well in p53 wild-type (MKN-45), or in p53 mutant-type (MKN-28) gastric cancer cells. Conclusions The data presented suggests that overexpression of the BAK gene can lead to apoptosis of gastric cancer cells in vitro, which does not appear to be dependent on p53 status. The action mechanism of BAK mediated apoptosis correlates with activation of caspase-3. This could be served as a potential strategy for further development of gastric cancer therapies.
Collapse
Affiliation(s)
- Qiang-Song Tong
- Department of Surgery, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Li-Duan Zheng
- Department of Pathology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Liang Wang
- Department of Surgery, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Jun Liu
- Department of Gastroenterology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Wei Qian
- Department of Gastroenterology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| |
Collapse
|
82
|
Kim JK, Kim KS, Ahn JY, Kim NK, Chung HM, Yun HJ, Cha KY. Enhanced apoptosis by a novel gene, Bak-like, that lacks the BH3 domain. Biochem Biophys Res Commun 2004; 316:18-23. [PMID: 15003505 DOI: 10.1016/j.bbrc.2004.01.173] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2004] [Indexed: 10/26/2022]
Abstract
In a variety of physiological settings, cells are eliminated by apoptosis-a genetically encoded process of cellular suicide. Bak, a member of the Bcl-2 protein family, accelerates apoptosis by an unknown mechanism. We have found a novel cDNA encoding a 101-amino acid protein that possesses a Bak-like sequence in our full-length cDNA bank and termed it Bak-like. This protein shares the conserved domains BH1 and BH2 with other pro-apoptotic proteins, but lacks the BH3 domain. Database searches identified this gene on chromosome 6, which could account for the cloned bak and bak-like transcripts by alternative splicing. Bak-like is expressed in a wide variety of tissues. Bak-like is different from bak by Southern blots using probes with or without homology to bak. Despite the loss of the BH3 sequence, bak-like did enhance apoptosis, but was less potent than bak. Confocal microscopy of HeLa cells revealed that EGFP-Bak-like was located diffusely throughout the cytosol. However, upon induction of apoptosis, EGFP-Bak-like redistributed into a punctuate pattern, colocalizing with mitochondria. Like bak, the bak-like gene product directly enhanced apoptotic cell death following an appropriate stimulus.
Collapse
Affiliation(s)
- Jin Kyeoung Kim
- Graduate School of Life science and Biotechnology, College of Medicine, Pochon CHA University, Seoul 135-081, Republic of Korea
| | | | | | | | | | | | | |
Collapse
|
83
|
Akhtar RS, Ness JM, Roth KA. Bcl-2 family regulation of neuronal development and neurodegeneration. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2004; 1644:189-203. [PMID: 14996503 DOI: 10.1016/j.bbamcr.2003.10.013] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2003] [Accepted: 10/27/2003] [Indexed: 01/03/2023]
Abstract
Neuronal cell death is a key feature of both normal nervous system development and neuropathological conditions. The Bcl-2 family, via its regulation of both caspase-dependent and caspase-independent cell death pathways, is uniquely positioned to critically control neuronal cell survival. Targeted gene disruptions of specific bcl-2 family members and the generation of transgenic mice overexpressing anti- or pro-apoptotic Bcl-2 family members have confirmed the importance of the Bcl-2 family in the nervous system. Data from studies of human brain tissue and experimental animal models of neuropathological conditions support the hypothesis that the Bcl-2 family regulates cell death in the mature nervous system and suggest that pharmacological manipulation of Bcl-2 family action could prove beneficial in the treatment of human neurological conditions such as stroke and neurodegenerative diseases.
Collapse
Affiliation(s)
- Rizwan S Akhtar
- Division of Pediatric Neurology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | | | | |
Collapse
|
84
|
Irusta PM, Hardwick JM. Neuronal apoptosis pathways in Sindbis virus encephalitis. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2004; 36:71-93. [PMID: 15171608 DOI: 10.1007/978-3-540-74264-7_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Sindbis virus infects neurons of the brain and spinal cord leading to neuronal apoptosis and encephalitis in mice. During postnatal development, neurons of mice remain susceptible to infection but become refractory to SV-induced programmed cell death. Failure to undergo programmed cell death results in a persistent infection. However, some neurovirulent strains of Sindbis virus overcome the age-dependent protective function in neurons, leading to enhanced apoptotic cell death in the central nervous system and higher mortality rates. Sindbis virus infections can also cause hind-limb paralysis due to the death of infected spinal cord motor neurons. However, spinal cord neuron death in older mice appears to occur by mechanisms that differ from classical apoptosis observed in newborn mice based on the morphology of dying neurons at these two sites. Sindbis virus infections of mosquitoes and some mosquito cell lines, on the other hand, do not induce cell death but persistent infections, a phenomenon also observed occasionally in cultured mammalian cells as well as in brains of infected mice surviving lethal infections. Thus, both viral and cellular factors contribute to the varied outcomes of infection. The molecular mechanisms that govern the susceptibility or resistance of particular cell types to SV-induced cell death are not well understood. Furthermore, the cellular execution machinery that produces the characteristic morphological distinctions between brain and spinal cord (i.e. apoptotic versus non-apoptotic) remain to be discovered.
Collapse
Affiliation(s)
- Pablo M Irusta
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, Maryland 21205, USA.
| | | |
Collapse
|
85
|
Fennell DA. Bcl-2 as a target for overcoming chemoresistance in small-cell lung cancer. Clin Lung Cancer 2003; 4:307-13. [PMID: 14609451 DOI: 10.3816/clc.2003.n.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Small-cell lung cancer (SCLC) is an aggressive malignancy that is frequently metastatic at presentation and has a poor prognosis. Although initially sensitive to primary therapy, acquisition of apoptosis resistance is typical, resulting in failure of secondary chemotherapy following relapse. Expression of the antiapoptosis protein Bcl-2 is prevalent in SCLC. The understanding of this oncoprotein's function has increased dramatically over the past decade. In vitro and in vivo evidence supports a role for overexpression of Bcl-2 in SCLC and supports the notion that it is a major factor contributing to apoptosis resistance. Targeting Bcl-2 may provide a novel therapeutic approach to overcoming chemoresistance in SCLC. This article discusses the relevance of Bcl-2 to apoptosis susceptibility in SCLC and its exploitation using gene silencing to improve the clinical outcome in this disease.
Collapse
Affiliation(s)
- Dean A Fennell
- Lung Cancer Section, Department of Medical Oncology, St Bartholomew's Hospital, London, United Kingdom.
| |
Collapse
|
86
|
Näpänkangas U, Lindqvist N, Lindholm D, Hallböök F. Rat retinal ganglion cells upregulate the pro-apoptotic BH3-only protein Bim after optic nerve transection. ACTA ACUST UNITED AC 2003; 120:30-7. [PMID: 14667574 DOI: 10.1016/j.molbrainres.2003.09.016] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Increased expression of Bim, a pro-apoptotic member of the Bcl-2 family, has been shown to be critical for neuronal apoptosis. To study the involvement of Bim in injury-induced cell death in retina, Bim expression was studied in normal rat retina and in retina after optic nerve transection using quantitative RT-PCR and immunohistochemistry. As a complement to this, the apoptotic regulators Bax, Bcl-2, caspase-3 and phosphorylated c-jun were studied. The relative levels of Bim mRNA in retina were significantly higher 4 days after optic nerve transection and below normal levels at 14 days after transection. A parallel increase in the number of Bim-immunoreactive cells in the retinal ganglion cell layer could be seen. Bim-immunoreactivity localized to retrogradely True Blue-labeled retinal ganglion cells. The relative mRNA levels for both Bax and Bcl-2 were higher at 4 days after transection when compared to normal. Immunoreactivity for Bax, Bcl-2 as well as for caspase-3 and phosphorylated c-jun, indicative of cell death, localized to True Blue-identified retinal ganglion cells 4 days after injury. Bcl-2 immunoreactivity was also seen on other cells, most likely Müller glia cells. In addition, optic nerve transection caused an increase in Bim, Bax, and Bcl-2 mRNA levels in optic nerve and superior colliculus. Our results suggest that Bim is involved in injury-induced retinal ganglion cell death and indicate that the increase in Bim and Bax expression promote cell death of axotomized retinal ganglion cells whereas the elevation in Bcl-2 in retina may contribute to the control of the extent of apoptosis after the optic nerve transection.
Collapse
Affiliation(s)
- Ulla Näpänkangas
- Department of Neuroscience, Units for Developmental Neuroscience, Uppsala University, S-75123 Uppsala, Sweden.
| | | | | | | |
Collapse
|
87
|
Lovell MA, Xie C, Xiong S, Markesbery WR. Wilms' tumor suppressor (WT1) is a mediator of neuronal degeneration associated with the pathogenesis of Alzheimer's disease. Brain Res 2003; 983:84-96. [PMID: 12914969 DOI: 10.1016/s0006-8993(03)03032-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Wilms' tumor suppressor (WT1), a 52- to 54-kda transcription factor, is the gene product of Wilms' tumor 1 (wt1), one of at least three genes involved in the development of a pediatric kidney cancer. Expression patterns of WT1 indicate that it is not restricted to the kidney but may play a role in the development and homeostasis of other tissues as well. WT1 has been implicated in various cellular processes including proliferation, differentiation, and apoptosis. High levels of WT1 induce apoptosis independent of p53, whereas low levels of WT1 inhibit apoptosis. Because apoptosis has been suggested to play a role in neurodegeneration in Alzheimer's disease (AD), immunohistochemistry of WT1 and paired helical filament (PHF) in serial sections was carried out. Immunohistochemical localization of WT1 and PHF showed the presence of WT1 in approximately 42% of PHF-positive neurofibrillary tangle containing-neurons. Laser confocal microscopy of hippocampal neuron cultures undergoing apoptosis induced by amyloid beta peptide (Abeta) or staurosporine demonstrated significant time-dependent elevations of WT1 correlating with increased levels of apoptosis. Blockade of WT1 transcription by antisense oligonucleotide reduced WT1 expression and prevented neuronal apoptosis in both Abeta- and staurosporine-treated cultures. Together, these data suggest a role for WT1 in the neurodegeneration observed in AD brain.
Collapse
Affiliation(s)
- Mark A Lovell
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA.
| | | | | | | |
Collapse
|
88
|
Regnström K, Ragnarsson EGE, Köping-Höggård M, Torstensson E, Nyblom H, Artursson P. PEI - a potent, but not harmless, mucosal immuno-stimulator of mixed T-helper cell response and FasL-mediated cell death in mice. Gene Ther 2003; 10:1575-83. [PMID: 12907949 DOI: 10.1038/sj.gt.3302054] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Polyethyleneimine (PEI) is one of the most effective gene delivery systems available today. However, very little is known about its ability to stimulate a systemic immune response and the molecular mechanisms thereof. However, this information is vital for the future development of new gene delivery systems. Here we address this issue by studying gene expression profiles from spleen lymphocytes after in vivo immunization of mice with PEI formulated with a reporter plasmid (PEI+) or the formulation alone (PEI-). PEI- was found to provoke the activation of genes with important immunostimulatory functions, but without the necessary costimulatory signals. PEI+ resulted in: a mixed Th1/Th2 response; activation of both CD8(+) and CD4(+) T cells, with a larger effect on CD4(+); and FasL-mediated antigen-induced cell death. A comparison of the immune responses of PEI+ with that of the clinically used tetanus toxoid-aluminum phosphate vaccine showed that the DNA vaccine provoked a stronger immune response as compared to the protein vaccine. However, many genes involved in other cellular responses such as apoptosis, stress responses and oncogenesis were activated in PEI+, supporting the theory of immunostimulation by danger genes, but also pointing toward possible adverse reactions such as Alzheimer's disease.
Collapse
Affiliation(s)
- K Regnström
- Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | | | | | | | | | | |
Collapse
|
89
|
Abstract
Apoptotic cell death plays a critical role in the development and functioning of the immune system. During differentiation, apoptosis weeds out lymphocytes lacking useful antigen receptors and those expressing dangerous ones. Lymphocyte death is also involved in limiting the magnitude and duration of immune responses to infection. In this review, we describe the role of the Bcl-2 protein family, and to a lesser extent that of death receptors (members of the tumor necrosis factor receptor family with a death domain), in the control of lymphoid and myeloid cell survival. We also consider the pathogenic consequences of failure of apoptosis in the immune system.
Collapse
Affiliation(s)
- Vanessa S Marsden
- Molecular Genetics of Cancer Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | | |
Collapse
|
90
|
Subramanian T, Chinnadurai G. Pro-apoptotic activity of transiently expressed BCL-2 occurs independent of BAX and BAK. J Cell Biochem 2003; 89:1102-14. [PMID: 12898509 DOI: 10.1002/jcb.10573] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BCL-2 suppresses apoptosis induced by a wide variety of stimuli in multiple cell types. Most of the in vitro studies that have examined the activity of BCL-2 have employed stable cell lines that ectopically express BCL-2. We have reported that BCL-2 is expressed at high levels in the absence of the 5'- and 3'-UTRs of the Bcl-2 gene and transient high level of expression results in potent cell death (Uhlmann et al., [1998]: JBC 278:17926-17932). Expression of BCL-2 under the transcriptional control of the cognate 5'- and 3'-UTRs express lower levels of BCL-2 and does not cause cell death. Our present results suggest that in contrast to BCL-2, transient expression of BCL-xL does not induce cell death and coexpression of BCL-xL with the pro-apoptotic BCL-2 does not suppress cell death. The pro-apoptotic activity of BCL-2 appears to involve activation of the cytochrome c/caspase 9/caspase 3 pathway. Elevated levels of BCL-2 expression results in N-terminal cleavage of BCL-2 at a novel site different from a previously identified caspase cleavage site at Asp 34 by a non-caspase protease. Transient expression of a BCL-2 mutant lacking aa 51-85 within the loop region induces efficient cell death and N-terminal cleavage of BCL-2 while a different deletion mutant lacking aa 30-91 induces reduced levels of cell death in the absence of BCL-2 cleavage suggesting that N-terminal processing of BCL-2 may be an amplification event in BCL-2-mediated cell death. Overexpression of BCL-2 in a Bax-null human colon cancer cell line (HCT116Bax-/-) induces efficient cell death. The pro-apoptotic activity of BCL-2 is also observed in a Bax-null cells in which BAK expression is inhibited by stable RNAi expression. Our results suggest that BCL-2 contains an intrinsic pro-apoptotic activity and can induce apoptosis independent of BAX and BAK under specific conditions.
Collapse
Affiliation(s)
- T Subramanian
- Institute for Molecular Virology, Saint Louis University School of Medicine, 3681 Park Ave., St. Louis, Missouri 63110, USA
| | | |
Collapse
|
91
|
Petit F, Arnoult D, Viollet L, Estaquier J. Intrinsic and extrinsic pathways signaling during HIV-1 mediated cell death. Biochimie 2003; 85:795-811. [PMID: 14585547 DOI: 10.1016/j.biochi.2003.09.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Infection with human immunodeficiency virus (HIV) is characterized by the gradual depletion of CD4+ T lymphocytes. The incorporation of the concept of apoptosis as a rationale to explain progressive T cell depletion has led to growing research in this field during the last 10 years. In parallel, the biochemical pathways implicated in programmed cell death have been extensively studied. Thus, the influence of mitochondrial control in the two major apoptotic pathways-the extrinsic and intrinsic pathways-is now well admitted. In this review, we summarized our current knowledge of the different pathways involved in the death of T cells in the course of HIV infection.
Collapse
Affiliation(s)
- Frédéric Petit
- Unité de Physiopathologie des Infections Lentivirales, Institut Pasteur, 28, rue du Dr Roux, 75724 Paris cedex 15, France
| | | | | | | |
Collapse
|
92
|
Hofmann ER, Milstein S, Hengartner MO. DNA-damage-induced checkpoint pathways in the nematode Caenorhabditis elegans. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2003; 65:467-73. [PMID: 12760063 DOI: 10.1101/sqb.2000.65.467] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- E R Hofmann
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | | | | |
Collapse
|
93
|
Wani KMY, Huilgol NG, Hongyo T, Shah HRK, Chatterjee N, Nair CKK, Nomura T. Genetic alterations in the coding region of the bak gene in uterine cervical carcinoma. Br J Cancer 2003; 88:1584-6. [PMID: 12771926 PMCID: PMC2377111 DOI: 10.1038/sj.bjc.6600944] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
A significant frequency of mutations (six missense and one silent) was found, for the first time, at the coding region of the bak gene (exons 3, 4 and 6) in 42 carcinomas of the uterine cervix, while no mutations were detected in 32 non-neoplastic cervix tissues. Bak mutations were observed more frequently in the advanced stage and mutated cancer tissues were more resistant to radiotherapy, although trends were not statistically significant because of small sample size.
Collapse
Affiliation(s)
- K M Y Wani
- Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
- Division of Radiation Oncology, Nanavati Hospital and Medical Research Centre, Mumbai 400056, India
- Biochemistry of Stress Response Section, Radiation Biology Division, BARC, Mumbai 400085, India
| | - N G Huilgol
- Division of Radiation Oncology, Nanavati Hospital and Medical Research Centre, Mumbai 400056, India
| | - T Hongyo
- Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - H Ryo K Shah
- Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
- Division of Radiation Oncology, Nanavati Hospital and Medical Research Centre, Mumbai 400056, India
| | - N Chatterjee
- Division of Radiation Oncology, Nanavati Hospital and Medical Research Centre, Mumbai 400056, India
| | - C K K Nair
- Biochemistry of Stress Response Section, Radiation Biology Division, BARC, Mumbai 400085, India
| | - T Nomura
- Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
- Department of Radiation Biology and Medical Genetics, Graduate School of Medicine, Osaka University, B4, 2-2 Yamada-Oka, Suita, Osaka 565-0871, Japan. E-mail:
| |
Collapse
|
94
|
Unoki M, Nakamura Y. EGR2 induces apoptosis in various cancer cell lines by direct transactivation of BNIP3L and BAK. Oncogene 2003; 22:2172-85. [PMID: 12687019 DOI: 10.1038/sj.onc.1206222] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
EGR2 plays a key role in the PTEN-induced apoptotic pathway. Using adenovirus-mediated gene transfer to 39 cancer cell lines, we found that EGR2 could induce apoptosis in a large proportion of these lines by altering the permeability of mitochondrial membranes, releasing cytochrome c and activating caspase-3, -8, and -9. Analysis by cDNA microarray and subsequent functional studies revealed that EGR2 directly transactivates expression of BNIP3L and BAK. Our results helped to clarify the molecular mechanism of the apoptotic pathway induced by PTEN-EGR2, and suggested that EGR2 may be an excellent target molecule for gene therapy to treat a variety of cancers.
Collapse
Affiliation(s)
- Motoko Unoki
- Laboratory of Molecular Medicine, Human Genome Center, Institute of Medical Science, The University of Tokyo, Japam
| | | |
Collapse
|
95
|
Fannjiang Y, Kim CH, Huganir RL, Zou S, Lindsten T, Thompson CB, Mito T, Traystman RJ, Larsen T, Griffin DE, Mandir AS, Dawson TM, Dike S, Sappington AL, Kerr DA, Jonas EA, Kaczmarek LK, Hardwick JM. BAK alters neuronal excitability and can switch from anti- to pro-death function during postnatal development. Dev Cell 2003; 4:575-85. [PMID: 12689595 DOI: 10.1016/s1534-5807(03)00091-1] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BAK is a pro-apoptotic BCL-2 family protein that localizes to mitochondria. Here we evaluate the function of BAK in several mouse models of neuronal injury including neuronotropic Sindbis virus infection, Parkinson's disease, ischemia/stroke, and seizure. BAK promotes or inhibits neuronal death depending on the specific death stimulus, neuron subtype, and stage of postnatal development. BAK protects neurons from excitotoxicity and virus infection in the hippocampus. As mice mature, BAK is converted from anti- to pro-death function in virus-infected spinal cord neurons. In addition to regulating cell death, BAK also protects mice from kainate-induced seizures, suggesting a possible role in regulating synaptic activity. BAK can alter neurotransmitter release in a direction consistent with its protective effects on neurons and mice. These findings suggest that BAK inhibits cell death by modifying neuronal excitability.
Collapse
Affiliation(s)
- Yihru Fannjiang
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
96
|
Kim HH, Kim K. Enhancement of TNF-alpha-mediated cell death in vascular smooth muscle cells through cytochrome c-independent pathway by the proteasome inhibitor. FEBS Lett 2003; 535:190-4. [PMID: 12560102 DOI: 10.1016/s0014-5793(02)03894-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
There is substantial evidence that cytokines induce apoptosis of vascular smooth muscle cells (VSMCs) in atherosclerosis. Its regulation, however, is not completely defined. The aim of this study is to investigate whether proteasome activity is related with apoptosis in VSMCs by tumor necrosis factor-alpha (TNF-alpha). Rat aorta smooth muscle cells were treated with TNF-alpha and proteasome inhibitor MG132 and then cell death was determined by morphology, viability, and DNA fragmentation. MG132 or TNF-alpha alone did not induce cell death. In contrast, co-treatment of TNF-alpha and proteasome inhibitor induced death and DNA degradation in VSMCs, suggesting proteasome inhibitor enhanced death activity of TNF-alpha. The death was not blocked by ascorbic acid but by nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine. Both caspase-3 and -8 were activated during the death by the proteasome inhibitor and TNF-alpha. The death was effectively blocked by the caspase-3 inhibitor z-DEVD-fmk, suggesting a role of caspase-3 in the death. Nonetheless, there were no significant alterations in the level of Bcl-2, Bcl-X(L), Bax and Bak by the proteasome inhibitor, nor any evidence of cytochrome (cyt) c release into cytosol from dying cells, suggesting that cyt c is not involved. These results suggest that proteasome inhibition potentiates TNF-mediated death in VSMCs in a cyt c-independent pathway. The present study proposes a new mechanism by which VSMCs undergo death by cytokines.
Collapse
Affiliation(s)
- Hak Hyung Kim
- College of Pharmacy, Chungbuk National University, Cheongju, Chungbuk, South Korea
| | | |
Collapse
|
97
|
Yang WL, Addona T, Nair DG, Qi L, Ravikumar TS. Apoptosis induced by cryo-injury in human colorectal cancer cells is associated with mitochondrial dysfunction. Int J Cancer 2003; 103:360-9. [PMID: 12471619 DOI: 10.1002/ijc.10822] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cryotherapy, a method of in situ ablation, is used in the treatment of colorectal liver metastases with variable results. During the treatment, the central area of treated tumor undergoes necrotic destruction by lethal cryo-injury; however, the cellular response of tumor exposed to sublethal cryo-injury at the peripheral zone is unclear. In our study, we have identified the induction of apoptosis by cryo-injury at -10 degrees C in 4 colorectal cancer cell lines (HT29, HCT116, KM12C and KM12SM). The apoptosis was characterized by chromatin condensation, transferase-mediated dUTP nick end-labeling (TUNEL) staining, proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) and cytokeratin 18, and activation of caspase-3. The occurrence and intensity of cryo-induced apoptosis did not correlate with the functional status of p53 in the cell lines studied. The expression of anti-apoptotic proteins (Bcl-2, Bcl-X(L)) and pro-apoptotic proteins (Bax, Bcl-X(S), Bad, and Bak) in response to cryo-injury varied in this cell line panel. The basal level of Bcl-2/Bax protein ratio correlated inversely to the apoptotic rate. We further demonstrated that Bax level decreased in cytosol and increased in mitochondria, followed by a loss of mitochondrial membrane potential after cryo-injury in HT29 cells. These findings indicate that cryo-injury induces apoptosis in colorectal cancer cells via disruption of mitochondrial integrity. The cryo-induced apoptosis was also identified in a nude mouse tumor xenograft model. Our elucidation of the apoptosis pathway induced by cryo-injury implies that synergistic combination of cryosurgery with pharmacological agents that augment of apoptosis induction may have clinical relevance in treating colorectal liver metastasis.
Collapse
Affiliation(s)
- Weng-Lang Yang
- Department of Surgery, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY 10467, USA
| | | | | | | | | |
Collapse
|
98
|
Abstract
Members of the Bcl-2 family are crucial integrators of survival and death signals in higher eukaryotes. Although recent studies have provided novel and quite unexpected insights into the mechanisms by which these proteins might issue life permits or death sentences in cells, we are still on the way to fully understand their modes of action. This review provides a snapshot on where we are on this journey and how we may exploit our knowledge on this family of proteins to unveil the mysteries of immune regulation.
Collapse
Affiliation(s)
- Christoph Borner
- Institute of Molecular Medicine and Cell Research, Albert-Ludwigs-University, Freiburg, Germany.
| |
Collapse
|
99
|
D'Agostino P, Ferlazzo V, Milano S, La Rosa M, Di Bella G, Caruso R, Barbera C, Grimaudo S, Tolomeo M, Feo S, Cillari E. Chemically modified tetracyclines induce cytotoxic effects against J774 tumour cell line by activating the apoptotic pathway. Int Immunopharmacol 2003; 3:63-73. [PMID: 12538035 DOI: 10.1016/s1567-5769(02)00213-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Here, we have studied the effects of chemically modified tetracyclines (CMTs) on apoptosis both at the level of the cytoplasmic proteolytic caspase cascade, and on Bcl-2 and c-myc mRNA expression in the J774 macrophage cell line. The results indicate that CMTs induce morphological changes consistent with apoptotic events, as clearly demonstrated both by the acridine orange and ethidium bromide staining, and by TUNEL and fragmentation ELISA assays. Furthermore, the analysis of the cell cycle by flow cytometry shows an evident apoptotic sub-G0G1 peak, without important modifications in the cell cycle distribution. CMTs induce programmed cell death (PCD) in a dose-dependent manner and CMT-8 is the strongest among them. CMT-1 and CMT-8 activate mainly caspase-8 as attested by the inhibitory effects of Z-VAD-fmk and Z-IEDT-fmk on CMT-induced apoptosis. Part of CMT-induced PCD is due to the activation of caspase-9, since it is reduced by the specific caspase-9 inhibitor, Z-LEHD-fmk. Besides, CMTs increase Bcl-2 and c-myc mRNA expression. Collectively, these data indicate that CMTs are potentially anti-tumour agents, since they strongly trigger apoptosis both activating the proteolytic system of the caspase family and modulating genes involved in PCD regulation.
Collapse
Affiliation(s)
- Pietro D'Agostino
- Department of Immuno-Haematology and Transfusion, University of Palermo, Palermo, Italy
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
100
|
Nasreen N, Mohammed KA, Sanders KL, Hardwick J, Van Horn RD, Sharma RK, Kilani M, Antony VB. Pleural mesothelial cells modulate polymorphonuclear leukocyte apoptosis in empyema. J Clin Immunol 2003; 23:1-10. [PMID: 12645855 DOI: 10.1023/a:1021958529763] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In bacterial empyema, the recruited polymorphonuclear leukocytes (PMN) represent important phagocytic cells involved in antibacterial defense. In this study we demonstrate that pleural fluids (PF) obtained from patients with empyema (EMP) contains significantly higher levels of granulocyte colony stimulating factor (GM-CSF), and PMN incubated in empyema (EMP) pleural fluid (PF) showed significantly less apoptosis than congestive heart failure (CHF) PF. Staphylococcus aureus-stimulated PMC released significantly (P < 0.001) higher levels of GM-CSF than resting PMC. Staphylococcus aureus-stimulated PMC (SPMC)-CM significantly (P < 0.001) inhibited PMN apoptosis. In SPMC-CM-incubated PMN the antiapoptotic gene Bcl-xL mRNA and protein expression was up-regulated; Bak mRNA and protein expression was down-regulated compared to control PMN. The active caspases activity significantly decreased. When SPMC-CM and EMP PF were immunodepleted with GM-CSF antibody, PMN apoptosis was significantly higher. The delay in apoptosis of PMN is in part attributable to the release of cytokine GM-CSF by activated PMC. These findings suggest that S. aureus-activated PMC extend PMN life span by modulating Bcl-xL and Bak gene expression and active caspases activity during acute inflammation and empyema.
Collapse
Affiliation(s)
- Najmunnisa Nasreen
- Division of Pulmonary and Critical Care Medicine, Veterans' Affairs Medical Center, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
| | | | | | | | | | | | | | | |
Collapse
|