151
|
Park HR, Ryoo IJ, Choo SJ, Hwang JH, Kim JY, Cha MR, Shin-Ya K, Yoo ID. Glucose-deprived HT-29 human colon carcinoma cells are sensitive to verrucosidin as a GRP78 down-regulator. Toxicology 2006; 229:253-61. [PMID: 17161515 DOI: 10.1016/j.tox.2006.11.049] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 10/24/2006] [Accepted: 11/06/2006] [Indexed: 11/28/2022]
Abstract
Glucose deprivation, a feature of poorly vascularized solid tumors, activates the unfolded protein response (UPR) which is a stress-signaling pathway in tumor cells that is associated with the molecular chaperone GRP78 and induction of GRP78 has been shown to protect them against programmed cell death. Thus, targeting glucose-deprived conditions may be a novel strategy in anticancer drug development. Based on that, we established a novel screening program for chaperone modulators that preferentially cytotoxic activity in cancer cells under glucose-deprived conditions. During the course of our screening system, we recently isolated an active compound, 326-2, from Penicillium verrucosum var. cyclopium and identified it as a down-regulator of the grp78 gene. As expected, 326-2 inhibited the expression of the GRP78 promoter under glucose-deprived conditions in a dose-dependent manner with an IC(50) value of 50nM. Furthermore, 326-2 was identified as verrucosidin, a pyrone-type polyketide, by ESI-MS analyses and various NMR spectroscopic methods. We found that verrucosidin prevents UPR-induced expression of protein, such as GRP78, whose expression is induced by glucose-deprived or by 2-deoxyglucose; this effect is not seen under normal growth conditions. The GRP78-inhibitory action of verrucosidin was dependent on strict hypoglycemic conditions and resulted in selective cell death of glucose-deprived HT-29 human colon cancer cells.
Collapse
Affiliation(s)
- Hae-Ryong Park
- Division of Food Science and Biotechnology, Kyungnam University, Masan 631-701, Republic of Korea
| | | | | | | | | | | | | | | |
Collapse
|
152
|
Pootrakul L, Datar RH, Shi SR, Cai J, Hawes D, Groshen SG, Lee AS, Cote RJ. Expression of stress response protein Grp78 is associated with the development of castration-resistant prostate cancer. Clin Cancer Res 2006; 12:5987-93. [PMID: 17062670 DOI: 10.1158/1078-0432.ccr-06-0133] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Induction of molecular chaperone Grp78 (78-kDa glucose-regulated protein) occurs in stress conditions that often characterize tumor microenvironments. We investigated the role of Grp78 in prostate cancer progression and the development of castration resistance, where cancer cells continue to survive despite the stress of an androgen-starved environment. EXPERIMENTAL DESIGN Immunohistochemistry was done to examine Grp78 expression in 219 prostate cancers from patients with pathologic stage T3N0M0 disease [androgen ablation naive (untreated) and androgen ablation exposed (treated)] and castration-resistant prostate cancer. Classification of tumors was based on intensity of Grp78 cytoplasmic immunoreactivity and percentage of immunoreactive tumor cells. The associations of Grp78 expression with prostate cancer recurrence (clinical and/or serum prostate-specific antigen) and survival were examined in the untreated stage T3N0M0 group. Grp78 expression was also analyzed in the androgen-dependent LNCaP and castration-resistant C42B cell lines. RESULTS The percentage of tumor cells expressing Grp78 was strongly associated with castration-resistant status (P = 0.005). Increased Grp78 expression was consistently associated with greater risk of prostate cancer recurrence and worse overall survival in patients who had not undergone prior hormonal manipulation. Grp78 expression was also increased in the castration-resistant LNCaP-derived cell line C42B and in LNCaP cells grown in androgen-deprived conditions compared with LNCaP cells grown in androgen-rich media. CONCLUSION Our findings show that up-regulation of Grp78 is associated with the development of castration resistance, possibly in part by augmenting cell survival as previously suggested, and may serve as an important prognostic indicator of recurrence in a subset of patients with T3N0M0 disease.
Collapse
Affiliation(s)
- Llana Pootrakul
- Department of Pathology, University of Southern California, Keck School of Medicine/USC Norris Comprehensive Cancer Center, Los Angeles, CA 90033, USA
| | | | | | | | | | | | | | | |
Collapse
|
153
|
Denoyelle C, Abou-Rjaily G, Bezrookove V, Verhaegen M, Johnson TM, Fullen DR, Pointer JN, Gruber SB, Su LD, Nikiforov MA, Kaufman RJ, Bastian BC, Soengas MS. Anti-oncogenic role of the endoplasmic reticulum differentially activated by mutations in the MAPK pathway. Nat Cell Biol 2006; 8:1053-63. [PMID: 16964246 DOI: 10.1038/ncb1471] [Citation(s) in RCA: 274] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2006] [Accepted: 08/08/2006] [Indexed: 12/30/2022]
Abstract
Dysfunction of the endoplasmic reticulum (ER) has been reported in a variety of human pathologies, including cancer. However, the contribution of the ER to the early stages of normal cell transformation is largely unknown. Using primary human melanocytes and biopsies of human naevi (moles), we show that the extent of ER stress induced by cellular oncogenes may define the mechanism of activation of premature senescence. Specifically, we found that oncogenic forms of HRAS (HRAS(G12V)) but not its downstream target BRAF (BRAF(V600E)), engaged a rapid cell-cycle arrest that was associated with massive vacuolization and expansion of the ER. However, neither p53, p16(INK4a) nor classical senescence markers--such as foci of heterochromatin or DNA damage--were able to account for the specific response of melanocytes to HRAS(G12V). Instead, HRAS(G12V)-driven senescence was mediated by the ER-associated unfolded protein response (UPR). The impact of HRAS on the UPR was selective, as it was poorly induced by activated NRAS (more frequently mutated in melanoma than HRAS). These results argue against premature senescence as a converging mechanism of response to activating oncogenes and support a direct role of the ER as a gatekeeper of tumour control.
Collapse
Affiliation(s)
- Christophe Denoyelle
- Department of Dermatology and Comprehensive Cancer Center, University of Michigan, 1500E Medical Center Drive, 4217 CCGC, Ann Arbor, MI 48109, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
154
|
Dall'Agnol M, Bernstein C, Bernstein H, Garewal H, Payne CM. Identification of S-nitrosylated proteins after chronic exposure of colon epithelial cells to deoxycholate. Proteomics 2006; 6:1654-62. [PMID: 16404723 DOI: 10.1002/pmic.200500240] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Apoptosis resistance, a condition favoring genomic instability, is associated with higher risk of colorectal cancer. Deoxycholate (DOC) is a hydrophobic bile salt found in high concentrations in colon cancer patients, and induces apoptosis in cultured colonic cells and ex vivo in colonic biopsies. We showed previously that the chronic exposure of colon cancer cells to increasing concentrations of DOC leads to apoptosis resistance, and the suggested mechanism involves oxidative/nitrosative stress. Nitric oxide (NO) is a key signaling molecule that regulates cell function in a variety of physiologic and pathophysiologic states. In part, NO exerts its actions by S-nitrosylation of target thiols, and several proteins are regulated through this PTM, including the caspases, the main effectors of apoptosis. Here, we performed a proteomics study in the DOC-induced apoptosis-resistant colon cell line, HCT-116RC. Its profile of S-nitrosylated proteins was compared to a control cell line not exposed to DOC. Eighteen differentially S-nitrosylated proteins were identified in the HCT-116RC cell line, 14 of these are novel targets of S-nitrosylation not previously reported. These proteins include cytoskeletal and signaling proteins, metabolic enzymes, chaperones, and redox- and differentiation-related proteins. These results broaden our knowledge of potential signal transduction pathways that may lead to the development of new biomarkers and therapy targets.
Collapse
Affiliation(s)
- Monique Dall'Agnol
- Department of Cell Biology and Anatomy, College of Medicine, University of Arizona, Tucson, AZ, USA
| | | | | | | | | |
Collapse
|
155
|
Ryoo IJ, Park HR, Choo SJ, Hwang JH, Park YM, Bae KH, Shin-Ya K, Yoo ID. Selective cytotoxic activity of valinomycin against HT-29 Human colon carcinoma cells via down-regulation of GRP78. Biol Pharm Bull 2006; 29:817-20. [PMID: 16595926 DOI: 10.1248/bpb.29.817] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glucose deprivation is a fundamental feature of poorly vascularized solid tumors and leads to activation of the molecular chaperone GRP78, which is associated with the unfolded protein response (UPR), a stress-signaling pathway, in tumor cells. We recently isolated an active compound, M126, that inhibits transcription from a GRP78 promoter reporter construct. M126 was identified as valinomycin by various spectroscopic methods. We found that valinomycin prevents UPR-induced protein expression, such as GRP78 and GRP94. The GRPs-inhibitory action of valinomycin severe hypoglycemic and results in selective cell death of the stressed cancer cells. Our findings demonstrate that GRP78 may be an excellent target for the use of cancer chemotherapy in the treatment of solid tumors.
Collapse
Affiliation(s)
- In-Ja Ryoo
- Laboratory of Antioxidant, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea
| | | | | | | | | | | | | | | |
Collapse
|
156
|
Luk JM, Lam CT, Siu AFM, Lam BY, Ng IOL, Hu MY, Che CM, Fan ST. Proteomic profiling of hepatocellular carcinoma in Chinese cohort reveals heat-shock proteins (Hsp27, Hsp70, GRP78) up-regulation and their associated prognostic values. Proteomics 2006; 6:1049-57. [PMID: 16400691 DOI: 10.1002/pmic.200500306] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
To facilitate the identification of candidate molecular biomarkers that are linked to the pathogenesis of hepatocellular carcinoma (HCC), we investigated protein-expression profiles of 146 tissue specimens including 67 pairs of tumors and adjacent non-tumors resected from HCC patients as well as 12 normal livers by 2-DE. Among the 1800 spots displayed in the liver proteome, a total of 90 protein species were found to be significantly different between the three groups (P < 0.05). Three of the top candidate markers up-regulated in HCC, with high receiver operating characteristic (ROC) curves, were identified by MS/MS analysis and belonged to the chaperone members: heat-shock protein (Hsp)27, Hsp70 and glucose-regulated protein (GRP)78. Over-expression of these chaperone proteins in HCC tissues was confirmed by Western blotting and immunohistochemistry. In correlation with clinico-pathological parameters, expression of Hsp27 was linked to alpha-fetoprotein level (P = 0.007) whereas up-regulation of GRP78 was associated with tumor venous infiltration (P = 0.035). No significant association of Hsp70 with any pathologic features was observed. The present HCC proteome analysis revealed that in response to the stressful cancerous microenvironment, tumor cells strived to increase the expression of chaperone proteins for cyto-protective function and to enhance tumor growth and metastasis.
Collapse
Affiliation(s)
- John M Luk
- Centre for the Study of Liver Disease and Department of Surgery, The University of Hong Kong, Hong Kong SAR, P. R. China.
| | | | | | | | | | | | | | | |
Collapse
|
157
|
Tsutsumi S, Namba T, Tanaka KI, Arai Y, Ishihara T, Aburaya M, Mima S, Hoshino T, Mizushima T. Celecoxib upregulates endoplasmic reticulum chaperones that inhibit celecoxib-induced apoptosis in human gastric cells. Oncogene 2006; 25:1018-29. [PMID: 16205636 DOI: 10.1038/sj.onc.1209139] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) induce apoptosis in cancer cells and this effect is involved in their antitumor activity. We recently demonstrated that NSAIDs upregulate GRP78, an endoplasmic reticulum (ER) chaperone, in gastric mucosal cells in primary culture. In the present study, induction of ER chaperones by NSAIDs and the effect of those chaperones on NSAID-induced apoptosis were examined in human gastric carcinoma cells. Celecoxib, an NSAID, upregulated ER chaperones (GRP78 and its cochaperones ERdj3 and ERdj4) but also C/EBP homologous transcription factor (CHOP), a transcription factor involved in apoptosis. Celecoxib also upregulated GRP78 in xenograft tumors, accompanying with the suppression of tumor growth in nude mice. Celecoxib caused phosphorylation of eukaryotic translation initiation factor 2 kinase (PERK) and eukaryotic initiation factor-2alpha (eIF2alpha) and production of activating transcription factor (ATF)4 mRNA. Suppression of ATF4 expression by small interfering RNA (siRNA) partially inhibited the celecoxib-dependent upregulation of GRP78. Celecoxib increased the intracellular Ca2+ concentration, while 1,2-bis(2-aminophenoxy)ethane-N,N,N'N'-tetraacetic acid, an intracellular Ca2+ chelator, inhibited the upregulation of GRP78 and ATF4. These results suggest that the Ca2+-dependent activation of the PERK-eIF2alpha-ATF4 pathway is involved in the upregulation of ER chaperones by celecoxib. Overexpression of GRP78 partially suppressed the apoptosis and induction of CHOP in the presence of celecoxib and this suppression was stimulated by coexpression of either ERdj3 or ERdj4. On the other hand, suppression of GRP78 expression by siRNA drastically stimulated cellular apoptosis and production of CHOP in the presence of celecoxib. These results show that upregulation of ER chaperones by celecoxib protects cancer cells from celecoxib-induced apoptosis, thus may decrease the potential antitumor activity of celecoxib.
Collapse
Affiliation(s)
- S Tsutsumi
- Graduate School of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
158
|
Mueller C, Emmrich J, Jaster R, Braun D, Liebe S, Sparmann G. Cis-hydroxyproline-induced inhibition of pancreatic cancer cell growth is mediated by endoplasmic reticulum stress. World J Gastroenterol 2006; 12:1569-76. [PMID: 16570349 PMCID: PMC4124289 DOI: 10.3748/wjg.v12.i10.1569] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the biological effects of cis-hydroxyproline (CHP) on the rat pancreatic carcinoma cell line DSL6A, and to examine the underlying molecular mechanisms.
METHODS: The effect of CHP on DSL6A cell proliferation was assessed by using BrdU incorporation. The expression of focal adhesion kinase (FAK) was characterized by Western blotting and immunofluorescence. Induction of endoplasmic reticulum (ER) stress was investigated by using RT-PCR and Western blotting for the glucose-related protein-78 (GRP78) and growth arrest and DNA inducible gene (GADD153). Cell viability was determined through measuring the metabolic activity based on the reduction potential of DSL6A cells. Apoptosis was analyzed by detection of caspase-3 activation and cleavage of poly(ADP-ribose) polymerase (PARP) as well as DNA laddering.
RESULTS: In addition to inhibition of proliferation, incubation with CHP induced proteolytic cleavage of FAK and a delocalisation of the enzyme from focal adhesions, followed by a loss of cell adherence. Simultaneously, we could show an increased expression of GRP78 and GADD153, indicating a CHP-mediated activation of the ER stress cascade in the DSL6A cell line. Prolonged incubation of DSL6A cells with CHP finally resulted in apoptotic cell death. Beside L-proline, the inhibition of intracellular proteolysis by addition of a broad spectrum protease inhibitor could abolish the effects of CHP on cellular functions and the molecular processes. In contrast, impeding the activity of apoptosis-executing caspases had no influence on CHP-mediated cell damage.
CONCLUSION: Our data suggest that the initiation of ER stress machinery by CHP leads to an activation of intracellular proteolytic processes, including caspase-independent FAK degradation, resulting in damaging pancreatic carcinoma cells.
Collapse
Affiliation(s)
- Christoph Mueller
- Department of Medicine, Division of Gastroenterology, University of Rostock, Ernst-Heydemann-Str. 6, D-18057 Rostock, Germany
| | | | | | | | | | | |
Collapse
|
159
|
Abstract
A number of lines of evidence, including nonhuman primate and human studies, suggest that regulatory pathways similar to those invoked by caloric restriction (CR) may be involved in determining human longevity. Thus, pharmaceuticals capable of mimicking the molecular mechanisms of life- and health-span extension by CR (CR mimetics) may have application to human health. CR acts rapidly, even in late adulthood, to begin to extend life- and health-span in mice. We have linked these effects with rapid changes in the levels of specific gene transcripts in the liver and the heart. Our results are consistent with the rapid effects of caloric intake on the lifespan and/or biochemistry and physiology of Drosophila, rodents, rhesus macaques and humans. To test the hypothesis that existing pharmaceuticals can mimic the physiologic effects of CR, we evaluated the effectiveness of glucoregulatory drugs and putative cancer chemo-preventatives in reproducing the hepatic gene-expression profiles produced by long-term CR (LTCR). We found that 8 weeks of metformin treatment was superior to 8 weeks of CR at reproducing the specific changes in transcript levels produced by LTCR. Consistent with these results, metformin reduces cancer incidence in diabetic humans and ameliorates the onset and severity of metabolic syndrome. Metformin extends the mean and maximum lifespans of female transgenic HER-2/neu mice by 8% and 13.1% in comparison with control mice. Phenformin, a close chemical relative of metformin, extends lifespan and reduces tumor incidence in C3H mice. These results indicate that gene-expression biomarkers can be used to identify promising candidate CR mimetics.
Collapse
Affiliation(s)
- Stephen R Spindler
- Department of Biochemistry, University of California, Riverside, CA 92521, USA.
| |
Collapse
|
160
|
Feldman DE, Chauhan V, Koong AC. The unfolded protein response: a novel component of the hypoxic stress response in tumors. Mol Cancer Res 2006; 3:597-605. [PMID: 16317085 DOI: 10.1158/1541-7786.mcr-05-0221] [Citation(s) in RCA: 233] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Hypoxia is a physiologically important endoplasmic reticulum (ER) stress that is present in all solid tumors. Numerous clinical studies have shown that tumor hypoxia predicts for decreased local control, increased distant metastases, and decreased overall survival in a variety of human tumors. Hypoxia selects for tumors with an increased malignant phenotype and increases the metastatic potential of tumor cells. Tumor cells respond to hypoxia and ER stress through the activation of the unfolded protein response (UPR). The UPR is an adaptive response to increase cell survival during ER stress. XBP-1 is a critical transcriptional regulator of this process and is required for tumor growth. Pancreatic ER kinase (PKR-like ER kinase) regulates the translational branch of the UPR and is also important in the growth of tumors. Although the exact mechanism has yet to be elucidated, recent data suggest that the UPR affects tumor growth through protection from apoptosis and may influence angiogenic signaling pathways. Targeting various components of the UPR is a promising therapeutic strategy. Understanding the relationship between hypoxia, the UPR, and tumor growth is crucial to improving current cancer therapies.
Collapse
Affiliation(s)
- Douglas E Feldman
- Department of Radiation Oncology, Stanford University Medical Center, Stanford, CA 94305-5152, USA
| | | | | |
Collapse
|
161
|
Krusekopf S, Roots I. St. John's wort and its constituent hyperforin concordantly regulate expression of genes encoding enzymes involved in basic cellular pathways. Pharmacogenet Genomics 2005; 15:817-29. [PMID: 16220113 DOI: 10.1097/01.fpc.0000175597.60066.3d] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES AND METHODS The effects of St. John's wort and hyperforin on gene expression were analysed in HepG2 cells by Affymetrix microarray hybridization and real time reverse transcription-PCR. RESULTS Both compounds increased mRNAs of the drug metabolizing enzymes CYP3A4, CYP1A1, CYP1A2 and the flavin containing monooxygenase FMO5, and of the multidrug resistance protein MRP2. CYP4F2 and the reduced nicotinamide adenine dinucleotide dehydrogenase NQO1 were downregulated. Expression of genes mediating cholesterol biosynthesis was decreased, while facilitated glucose transporters and glycolysis genes were induced, indicating increased glucose metabolism. Changes of a considerable number of additional transcripts corresponded to reports on gene regulation by hypoxia. Endoplasmic reticulum stress-regulated genes involved in unfolded protein response and in protection of cells from apoptosis were downregulated. Other calcium binding proteins were affected by both treatments, suggesting an increase in intracellular calcium. CONCLUSIONS St. John's wort and hyperforin concordantly affected expression of genes not only mediating metabolism and transport of exogenous and endogenous compounds, but also involved in energy metabolism, intracellular calcium regulation, cell proliferation and apoptosis.
Collapse
Affiliation(s)
- Solveigh Krusekopf
- Institute of Clinical Pharmacology, Charité Campus Mitte, Charité University Medical Center, Humboldt University of Berlin, Berlin, Germany.
| | | |
Collapse
|
162
|
Cullinan SB, Diehl JA. Coordination of ER and oxidative stress signaling: the PERK/Nrf2 signaling pathway. Int J Biochem Cell Biol 2005; 38:317-32. [PMID: 16290097 DOI: 10.1016/j.biocel.2005.09.018] [Citation(s) in RCA: 435] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2005] [Revised: 08/31/2005] [Accepted: 09/29/2005] [Indexed: 12/16/2022]
Abstract
In the broadest sense, cellular stress describes conditions wherein cells encounter and react to a 'non-normal' state. Perturbations may originate through both extracellular and intracellular means. Whereas transient levels of stress are expected to occur on a regular basis, a series of checks and balances ensures that cells are well equipped to maintain a homeostatic state. In the case of supra-physiological stress signaling, cellular challenges are more severe, and programmed cell death may be the best option for the organism. The ability of a cell, and by extension, an organism, to adequately manage cellular stress is fundamental--a question of life or death. The endoplasmic reticulum (ER) is exquisitely poised to sense and respond to cellular stresses including those that result from metabolic and/or protein folding imbalances. In response to stress originating from within the ER, the PERK and Ire1 protein kinases, along with other proximal signaling molecules, initiate a program of transcriptional and translational regulation termed the unfolded protein response. A consequence of ER stress is the accumulation of reactive oxygen species that promotes a state of oxidative stress. PERK signaling, via activation of the Nrf2 and ATF4 transcription factors, coordinates the convergence of ER stress with oxidative stress signaling. Here we discuss progress regarding the signaling pathways involved in these cellular stresses and the implications of the intersection between the two signaling pathways.
Collapse
Affiliation(s)
- Sara B Cullinan
- The Leonard and Madlyn Abramson Family Cancer Research Institute and Cancer Center, Philadelphia, PA 19104, USA
| | | |
Collapse
|
163
|
Dhahbi JM, Mote PL, Fahy GM, Spindler SR. Identification of potential caloric restriction mimetics by microarray profiling. Physiol Genomics 2005; 23:343-50. [PMID: 16189280 DOI: 10.1152/physiolgenomics.00069.2005] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To facilitate the development of assays for the discovery of pharmaceuticals capable of mimicking the effects of caloric restriction (CR) on life- and healthspan (CR mimetics), we evaluated the effectiveness of glucoregulatory and putative cancer chemopreventatives in reproducing the hepatic gene expression profile produced by long-term CR (LTCR), using Affymetrix microarrays. We have shown that CR initiated late in life begins to extend lifespan, reduce cancer as a cause of death, and reproduce approximately three-quarters of the genomic effects of LTCR in 8 wk (CR8). Eight weeks of metformin treatment was superior to CR8 at reproducing LTCR-like gene expression changes, maintaining a superior number of such changes over a broad range of statistical stringencies, and producing more Gene Ontology terms overlapping those produced by LTCR. Consistent with these results, metformin has been shown to reduce cancer incidence in mice and humans. Phenformin, a chemical cousin of metformin, extends lifespan and reduces tumor incidence in mice. Taken together, these results indicate that gene expression biomarkers can be used to identify promising candidate CR mimetics.
Collapse
Affiliation(s)
- Joseph M Dhahbi
- Department of Biochemistry, University of California, Riverside, California 92521, USA
| | | | | | | |
Collapse
|
164
|
Xing X, Lai M, Wang Y, Xu E, Huang Q. Overexpression of glucose-regulated protein 78 in colon cancer. Clin Chim Acta 2005; 364:308-15. [PMID: 16182273 DOI: 10.1016/j.cca.2005.07.016] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Revised: 07/24/2005] [Accepted: 07/26/2005] [Indexed: 11/16/2022]
Abstract
BACKGROUND The 78 kDa glucose-regulated protein (GRP78) has been implicated in the development of tumorigenicity, drug resistance, and cytotoxic immunology. We investigated the expression pattern of GRP78 at the protein and mRNA level in human colon carcinoma, colon adenoma and normal colon mucosa. METHODS Two-dimensional (2-D) gel electrophoresis, electrospray ionization tandem mass spectrometry, immunoblot analysis, reverse-transcriptase PCR and immunohistochemistry were used on colon normal and cancer tissues. RESULTS Comparative 2-D gel electrophoresis of individual-matched colon normal and cancer tissues revealed 15 protein spots with concordantly increased and 20 protein spots with concordantly decreased intensity in tumor tissue. Fourteen of these proteins were identified by tandem mass spectrometry. One of the identified proteins, GRP78, exhibited a marked up-regulation in colon cancer tissue. This result was further confirmed by Western blot and immunohistochemical analysis. Immunohistochemistry also revealed increased cytoplasmic GRP78 expression with progression along the normal tissue-adenoma-carcinoma sequence. However, to our surprise, there was essentially no difference in the relative mRNA expression levels of GRP78 between normal and colon tumors. CONCLUSIONS Our findings indicate that overexpression of GRP78 protein may be an important biomarker for malignant transformation, and increased expression might be related with the posttranscriptional regulation of GRP78 in tumor tissues.
Collapse
Affiliation(s)
- Xiaoming Xing
- Department of Pathology and Pathophysiology, Center for Environmental Genomics, School of Medicine, Zhejiang University, Hangzhou 310031, PR China
| | | | | | | | | |
Collapse
|
165
|
Papandreou I, Krishna C, Kaper F, Cai D, Giaccia AJ, Denko NC. Anoxia is necessary for tumor cell toxicity caused by a low-oxygen environment. Cancer Res 2005; 65:3171-8. [PMID: 15833847 DOI: 10.1158/0008-5472.can-04-3395] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cells exposed to oxygen deprivation in vitro have been shown to reduce proliferation and/or engage in programmed cell death. There is considerable controversy in the literature as to the role of hypoxia-inducible factor-1 (HIF-1) and HIF-1 target genes in initiating these responses. We therefore examined the oxygen dependence and the role of the hypoxia-responsive transcription factor HIF-1 in making the cellular death decision. Oxygen concentrations as low as 0.5% did not alter the growth of HIF-1-proficient or HIF-1-deficient murine fibroblasts, or human tumor cells, despite the appropriate induction of HIF-1 target genes. Severe hypoxia (<0.01% oxygen) did induced apoptosis, resulting in decreased colony formation, chromatin condensation, DNA fragmentation, and caspase activation but also independent of HIF1alpha status. Transcriptional induction of HIF-1-dependent genes putatively involved in cell death like BNip3 and BNip3L was therefore disassociated from hypoxia-dependent toxicity. Likewise, forced overexpression of a nondegradable form of HIF-1alpha in several human tumor cell lines was not sufficient to induce apoptosis under normoxic conditions. Taken together, these findings indicate that additional molecular events are triggered by anoxia in a HIF-1-independent manner, and these changes are necessary for cell death observed in low-oxygen environments.
Collapse
Affiliation(s)
- Ioanna Papandreou
- Department of Radiation Oncology, Division of Radiation and Cancer Biology, Stanford University School of Medicine, Stanford, California, USA
| | | | | | | | | | | |
Collapse
|
166
|
Ramsay RG, Ciznadija D, Mantamadiotis T, Anderson R, Pearson R. Expression of stress response protein glucose regulated protein-78 mediated by c-Myb. Int J Biochem Cell Biol 2005; 37:1254-68. [PMID: 15778089 DOI: 10.1016/j.biocel.2004.12.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2004] [Revised: 12/10/2004] [Accepted: 12/23/2004] [Indexed: 10/25/2022]
Abstract
Glucose regulated protein-78, GRP78 has been implicated in the protection of tumor cells from cytotoxic damage and apoptosis. When protein profiles of colon cell lines were investigated we found remarkably high GRP78 expression in two cell lines. These cell lines express elevated levels of the transcription factor c-Myb due to genomic amplification of the c-myb locus and we hypothesized that c-Myb regulates GRP78 expression in colon cancer cells. The promoters of human and murine GRP78 and the related family member GRP94 were examined and potential c-Myb binding sites were identified and characterized. DNA binding studies with recombinant c-Myb and nuclear extracts together with ChIP assays on colon cell lines validated these sites. Endogenous GRP78 expression was further induced in these colon cells in response to Thapsigargin treatment, a potent inducer of the unfolded protein response. Transactivation studies with the human GRP78 promoter in colon cell lines showed reporter activity was dependent upon the presence of a conserved c-Myb binding site independent of sequences associated with the unfolded protein response. Finally, over-expression of c-Myb induced the endogenous GRP78 gene. These data suggest that amplification of c-myb in tumor cells may lead to robust GRP78 gene induction, which may in turn assist cells in survival under conditions of oxygen deprivation and nutrient stress.
Collapse
Affiliation(s)
- Robert G Ramsay
- Differentiation and Transcription Laboratory, Trescowthick Research Laboratories, Peter MacCallum Cancer Centre, St. Andrews Place, East Melbourne 3002, Australia.
| | | | | | | | | |
Collapse
|
167
|
|
168
|
Wang Q, He Z, Zhang J, Wang Y, Wang T, Tong S, Wang L, Wang S, Chen Y. Overexpression of endoplasmic reticulum molecular chaperone GRP94 and GRP78 in human lung cancer tissues and its significance. ACTA ACUST UNITED AC 2005; 29:544-51. [PMID: 16297569 DOI: 10.1016/j.cdp.2005.09.010] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2005] [Indexed: 11/30/2022]
Abstract
BACKGROUND To investigate the relationship between the expression of glucose-regulated protein94 (GRP94) and GRP78 at the level of mRNA and protein in vivo and in human lung cancer. METHODS RT-PCR, real-time PCR, immunohistochemistry and/or Western blot were used in 54 cases of lung cancer and corresponding normal lung tissue. RESULTS The expression pattern of GRP94 and GRP78 was similar. There was a significant overexpression of GRP94 and GRP78 at both mRNA and protein levels in cancer tissues as compared to normal tissues. The relative levels of GRP94 and GRP78 mRNA evaluated by RT-PCR in cancer and normal lung tissue were: GRP94: 3.48+/-2.06 versus 2.01+/-1.83; GRP78: 3.64+/-1.87 versus 2.21+/-1.54; by real-time PCR were: GRP94: 2.89+/-0.64 versus 1.12+/-0.54; GRP78: 2.56+/-0.82 versus 0.96+/-0.42. The relative level of GRP94 and GRP78 protein by Western blot in cancer and normal lung tissue were: GRP94: 3.46+/-1.72 versus 1.81+/-0.92; GRP78: 4.84+/-2.55 versus 1.91+/-1.15, indicating an approximate 2-fold and a 3-fold increase in GRP94 and GRP78 protein in cancer tissue as compared with normal tissue. Immunohistochemistry result for GRP94 and GRP78 in cancer and normal tissue was similar, that is: a stronger stain was observed in cancer tissue (main intensity of staining ++ to +++) compared to normal tissue (main intensity of staining + to ++). All the difference for GRP94 and GRP78 between the two tissues were significant (p<0.05). Furthermore, the overexpression of GRP94 and GRP78 in the cancer tissue correlated with grade of differentiation and stage of tumors. There was stronger expression in poorly differentiated tumors than in well-moderately differentiated tumors (p<0.05). There was also stronger expression in stage III than in stages I and II tumors (p<0.05). No statistically significant differences were found among various pathologic types of tumors. Correlation analysis showed that there is a positive correlation between GRP94 and GRP78. CONCLUSION The expression pattern of GRP94 and GRP78 was similar in human lung cancer. They both were related with the differentiation and progression of the cancer. The expression at mRNA and protein level may be valuable in evaluating the grade of differentiation and clinical stage of human lung cancer.
Collapse
Affiliation(s)
- Qi Wang
- Department of Respiratory, the Second Hospital affiliated to Dalian Medical University, Dalian 116023, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
169
|
Ma Y, Hendershot LM. ER chaperone functions during normal and stress conditions. J Chem Neuroanat 2004; 28:51-65. [PMID: 15363491 DOI: 10.1016/j.jchemneu.2003.08.007] [Citation(s) in RCA: 323] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2003] [Revised: 12/21/2003] [Accepted: 12/21/2003] [Indexed: 12/25/2022]
Abstract
Nearly all resident proteins of the organelles along the secretory pathway, as well as proteins that are expressed at the cell surface or secreted from the cell, are first co-translationally translocated into the lumen of the endoplasmic reticulum (ER) as unfolded polypeptide chains. Immediately after entering the ER, they are often modified with N-linked glycans, are folded into the appropriate secondary and tertiary structures, which are stabilized by disulfide bonds, and finally in many cases are assembled into multimeric complexes. These processes are aided and monitored by ER chaperones and folding enzymes. When cells experience conditions that alter the ER environment, protein folding can be dramatically affected and can lead to the accumulation of unfolded proteins in this organelle. This in turn activates a signaling response, which is shared among all eukaryotic organisms, termed the unfolded protein response (UPR). The hallmark of this response is the coordinate transcriptional up-regulation of ER chaperones and folding enzymes. A major role for the increased levels of chaperones and folding enzymes during conditions of ER stress is to provide the same functions they carry out during normal physiological conditions. This includes preventing unfolded and incompletely folded proteins from aggregating and promoting the proper folding and assembly of proteins in the ER. During conditions of ER stress, many proteins are unable to fold properly and the requirements for chaperones are therefore increased. However, more recently it has become clear that some ER chaperones are also involved in signaling the ER stress response, targeting misfolded proteins for degradation and perhaps even shutting down the UPR when the stress subsides. In addition, during some normal physiological conditions, like plasma cell differentiation where there is an increased demand in the secretory capacity of B cells, the levels of various ER chaperones are also up-regulated via at least part of the UPR pathway. In order to discuss these various functions of ER chaperones, we will begin with the roles of ER chaperones and folding enzymes during normal physiological conditions and then discuss their roles during ER stress.
Collapse
Affiliation(s)
- Yanjun Ma
- Department of Genetics and Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | |
Collapse
|
170
|
Abstract
Having accumulated mutations that overcome cell-cycle and apoptotic checkpoints, the main obstacle to survival faced by a cancer cell is the restricted supply of nutrients and oxygen. These conditions impinge on protein folding in the endoplasmic reticulum and activate a largely cytoprotective signalling pathway called the unfolded protein response. Prolonged activation of this response can, however, terminate in apoptosis. Recent delineation of the components of this response, coupled with several clinical studies, indicate that it is uniquely poised to have a role in regulating the balance between cancer cell death, dormancy and aggressive growth, as well as altering the sensitivity of solid tumours to chemotherapeutic agents.
Collapse
Affiliation(s)
- Yanjun Ma
- Department of Genetics and Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
| | | |
Collapse
|
171
|
Bonnet R, Pavlovic S, Lehmann J, Rommelspacher H. The strong inhibition of triosephosphate isomerase by the natural beta-carbolines may explain their neurotoxic actions. Neuroscience 2004; 127:443-53. [PMID: 15262334 DOI: 10.1016/j.neuroscience.2004.05.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2004] [Accepted: 05/03/2004] [Indexed: 10/26/2022]
Abstract
The natural beta-carbolines (BC) closely resemble the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in structure. The N-methylated beta-carbolinium ions (BC+) are potent inhibitors of mitochondrial respiration and are nigrostriatal neurotoxins. Utilizing [3H]BC, we have identified several proteins to which BC binds with high affinity (e.g. the chaperone member glucose regulated protein 78, the enzyme carboxylesterase, the cytochrome P450 2E1, the enzyme monoamine oxidase B and a small G-protein of the Rho subfamily). In the present study we isolated a protein from bovine brain to which [3H]BC binds with high affinity and identified it being the enzyme triosephosphate isomerase (TPI; EC 5.3.1.1.). 2,9-Dimethyl-BC+ was the most potent inhibitor of TPI, clearly more potent than the known inhibitors. TPI deficiency is a rare disorder in humans characterized by a severe progressive extrapyramidal course. Thus, TPI inhibition could contribute to neurodegeneration observed after injection of BCs into substantia nigra. Furthermore, the findings fit into the hypothesis of BCs as endogenous toxins responsible for neurodegeneration.
Collapse
Affiliation(s)
- R Bonnet
- Section of Clinical Neurobiology, Clinic of Psychiatry and Psychotherapy, Charité, Campus Benjamin Franklin, Free University, Eschenallee 3, 14050 Berlin, Germany
| | | | | | | |
Collapse
|
172
|
Arap MA, Lahdenranta J, Mintz PJ, Hajitou A, Sarkis AS, Arap W, Pasqualini R. Cell surface expression of the stress response chaperone GRP78 enables tumor targeting by circulating ligands. Cancer Cell 2004; 6:275-84. [PMID: 15380518 DOI: 10.1016/j.ccr.2004.08.018] [Citation(s) in RCA: 326] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2004] [Revised: 07/07/2004] [Accepted: 08/18/2004] [Indexed: 11/16/2022]
Abstract
We have recently identified glucose-regulated protein-78 (GRP78) as a relevant molecular target expressed in metastatic tumors by fingerprinting the circulating repertoire of antibodies from cancer patients. Here we design and evaluate a ligand-receptor system based on the tumor cell membrane expression of GRP78. We show that GRP78 binding peptide motifs target tumor cells specifically in vivo and in human cancer specimens ex vivo. Moreover, synthetic chimeric peptides composed of GRP78 binding motifs fused to a programmed cell death-inducing sequence can suppress tumor growth in xenograft and isogenic mouse models of prostate and breast cancer. Together, these preclinical data validate GRP78 on the tumor cell surface as a functional molecular target that may prove useful for translation into clinical applications.
Collapse
Affiliation(s)
- Marco A Arap
- The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | | | | | | | | | | | | |
Collapse
|
173
|
Mayer MP. Recruitment of Hsp70 chaperones: a crucial part of viral survival strategies. Rev Physiol Biochem Pharmacol 2004; 153:1-46. [PMID: 15243813 DOI: 10.1007/s10254-004-0025-5] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Virus proliferation depends on the successful recruitment of host cellular components for their own replication, protein synthesis, and virion assembly. In the course of virus particle production a large number of proteins are synthesized in a relatively short time, whereby protein folding can become a limiting step. Most viruses therefore need cellular chaperones during their life cycle. In addition to their own protein folding problems viruses need to interfere with cellular processes such as signal transduction, cell cycle regulation and induction of apoptosis in order to create a favorable environment for their proliferation and to avoid premature cell death. Chaperones are involved in the control of these cellular processes and some viruses reprogram their host cell by interacting with them. Hsp70 chaperones, as central components of the cellular chaperone network, are frequently recruited by viruses. This review focuses on the function of Hsp70 chaperones at the different stages of the viral life cycle emphasizing mechanistic aspects.
Collapse
Affiliation(s)
- M P Mayer
- Zentrum für Molekulare Biologie, Universität Heidelberg, Im Neuenheimer Feld 282, 69120, Heidelberg, Germany.
| |
Collapse
|
174
|
Tsuchiya T, Dhahbi JM, Cui X, Mote PL, Bartke A, Spindler SR. Additive regulation of hepatic gene expression by dwarfism and caloric restriction. Physiol Genomics 2004; 17:307-15. [PMID: 15039484 DOI: 10.1152/physiolgenomics.00039.2004] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Disrupted growth hormone/insulin-like growth factor-1 signaling (DF) and caloric restriction (CR) extend life span and delay the onset of age-related diseases in rodents. In combination, these interventions additively extend life span. To investigate the molecular basis for these effects, we performed genome-wide, microarray expression analysis of liver from homozygous and heterozygous Ames dwarf mice fed ad libitum or CR. CR and DF additively affected a group of 95 genes. Individually and together, DF and CR independently affected the expression of 212 and 77 genes, respectively. These results indicate that DF and CR affect overlapping sets of genes and additively affect a subset of genes. Together, the interventions produced changes in gene expression consistent with increased insulin, glucagon and catecholamine sensitivity, gluconeogenesis, protein turnover, lipid β-oxidation, apoptosis, and xenobiotic and oxidant metabolism; and decreased cell proliferation, lipid and cholesterol synthesis, and chaperone expression. These data suggest that the additive effects of DF and CR on life span develop from their additive effects on the level of expression of some genes and from their independent effects on other genes. These results provide a novel and focused group of genes closely associated with the regulation of life span in mammals.
Collapse
Affiliation(s)
- Tomoshi Tsuchiya
- Department of Biochemistry, University of California, Riverside 92521, USA
| | | | | | | | | | | |
Collapse
|
175
|
Dhahbi JM, Kim HJ, Mote PL, Beaver RJ, Spindler SR. Temporal linkage between the phenotypic and genomic responses to caloric restriction. Proc Natl Acad Sci U S A 2004; 101:5524-9. [PMID: 15044709 PMCID: PMC397416 DOI: 10.1073/pnas.0305300101] [Citation(s) in RCA: 197] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2003] [Indexed: 12/20/2022] Open
Abstract
Caloric restriction (CR), the consumption of fewer calories while avoiding malnutrition, decelerates the rate of aging and the development of age-related diseases. CR has been viewed as less effective in older animals and as acting incrementally to slow or prevent age-related changes in gene expression. Here we demonstrate that CR initiated in 19-month-old mice begins within 2 months to increase the mean time to death by 42% and increase mean and maximum lifespans by 4.7 (P = 0.000017) and 6.0 months (P = 0.000056), respectively. The rate of age-associated mortality was decreased 3.1-fold. Between the first and second breakpoints in the CR survival curve (between 21 and 31 months of age), tumors as a cause of death decreased from 80% to 67% (P = 0.012). Genome-wide microarray analysis of hepatic RNA from old control mice switched to CR for 2, 4, and 8 weeks showed a rapid and progressive shift toward the gene expression profile produced by long-term CR. This shift took place in the time frame required to induce the health and longevity effects of CR. Shifting from long-term CR to a control diet, which returns animals to the control rate of aging, reversed 90% of the gene expression effects of long-term CR within 8 weeks. These results suggest a cause-and-effect relationship between the rate of aging and the CR-associated gene expression biomarkers. Therefore, therapeutics mimicking the gene-expression biomarkers of CR may reproduce its physiological effects.
Collapse
Affiliation(s)
- Joseph M Dhahbi
- BioMarker Pharmaceuticals, Incorporated, 900 East Hamilton Avenue, Campbell, CA 95008, USA
| | | | | | | | | |
Collapse
|
176
|
Flores-Diaz M, Higuita JC, Florin I, Okada T, Pollesello P, Bergman T, Thelestam M, Mori K, Alape-Giron A. A cellular UDP-glucose deficiency causes overexpression of glucose/oxygen-regulated proteins independent of the endoplasmic reticulum stress elements. J Biol Chem 2004; 279:21724-31. [PMID: 15020602 DOI: 10.1074/jbc.m312791200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
A low level of UDP-Glc occurs in cells exposed to hypoxia or glucose starvation. This work reveals that a 65% reduction in the cellular UDP-Glc level causes up-regulation of the mitochondrial chaperone GRP75 and the endoplasmic reticulum (ER) resident chaperones GRP58, ERp72, GRP78, GRP94, GRP170, and calreticulin. Conditions that cause misfolding of proteins within the ER activate the transcription factors ATF6alpha/beta and induce translation of the transcription factors XBP-1/TREB5 and ATF4/CREB2. These transcription factors induce the overexpression of ER chaperones and CHOP/GADD153. However, the 65% decrease in the cellular UDP-Glc level does not cause activation of ATF6alpha, splicing of XBP-1/TREB5, induction of ATF4/CREB2, or expression of CHOP/GADD153. The activity of the promoters of the ER chaperones is increased in UDP-Glc-deficient cells, but the activity of the CHOP/GADD153 promoter is not affected, in comparison with their respective activities in cells having compensated for the UDP-Glc deficiency. The results demonstrate that the unfolded protein response remains functionally intact in cells with a 65% decrease in the cellular UDP-Glc level and provide evidence that this decrease is a stress signal in mammalian cells, which triggers the coordinate overexpression of mitochondrial and ER chaperones, independently of the ER stress elements.
Collapse
Affiliation(s)
- Marietta Flores-Diaz
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | | | | | | | | | | | | | | | | |
Collapse
|
177
|
Massa C, Guiducci C, Arioli I, Parenza M, Colombo MP, Melani C. Enhanced Efficacy of Tumor Cell Vaccines Transfected with Secretable hsp70. Cancer Res 2004; 64:1502-8. [PMID: 14973071 DOI: 10.1158/0008-5472.can-03-2936] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tumor immunotherapy has exploited the ability of heat shock proteins to chaperone precursors of antigenic peptides to antigen-presenting cells and to activate efficiently an immune response against tumor-associated antigens. The most common strategy is based on the purification of heat shock protein-peptide complexes from tumor cell lines or from tumor surgical samples for in vivo administration. In this article, we have modified the murine-inducible hsp70 into a secreted protein and engineered tumor cells to secrete constitutively their antigenic repertoire associated with the hsp70 protein. In vitro studies showed that the relocalization of hsp70 from the cytoplasm to the secretory pathway did not modify the ability of hsp70 to interact with peptides derived either from natural tumor-associated antigens or model antigens, and that antigen-presenting cells specifically took up the secreted hsp70 and presented the chaperoned epitopes to T cells. In vivo studies showed that tumors secreting hsp70 displayed increased immunogenicity, with induction of a strong and specific CTL response. Mice injected with hsp70-secreting tumors showed increased survival and impaired tumor take compared with mice bearing parental tumors. More than 70% of mice rejected tumor cells secreting hsp70 through mechanisms that involve T lymphocytes and natural killer cells, with the induction of a memory response in the case of T lymphocytes. Moreover, hsp70 secretion increased the immunogenic potential of tumor cell vaccines.
Collapse
Affiliation(s)
- Chiara Massa
- Immunotherapy and Gene Therapy Unit, Department of Experimental Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori, via Venezian 1, 20133 Milan, Italy
| | | | | | | | | | | |
Collapse
|
178
|
Abstract
We identified a new gene, called p8, which showed a strong induction during the acute phase of pancreatitis. Further experiments have shown that p8 mRNA is activated in response to several stresses and that its activation is not restricted to pancreatic cells. p8 is a nuclear protein and biochemical and biophysical studies showed that p8 was in many structural aspects very similar to the HMG (high mobility group) proteins, although sharing with them low amino acid sequence homology. Also, p8 was found overexpressed in many human cancers. Therefore, we wondered whether the p8-mediated response to cellular stress was necessary for tumor establishment. Subcutaneous or intraperitoneal injections of transformed p8-expressing fibroblasts led to tumor formation in nude mice, but no tumor was observed with transformed p8-deficient cells. Restoring p8 expression in transformed p8-deficient fibroblasts led to tumor formation demonstrating that p8 expression is necessary for tumor development and suggesting that the stress-response mechanisms governed by p8 are required for tumor establishment.
Collapse
Affiliation(s)
- Sophie Vasseur
- Inserm EMI 0116, 163, avenue de Luminy, Parc Scientifique et Technologique de Luminy, BP 172, 13009 Marseille, France
| | | |
Collapse
|
179
|
Hung CC, Ichimura T, Stevens JL, Bonventre JV. Protection of renal epithelial cells against oxidative injury by endoplasmic reticulum stress preconditioning is mediated by ERK1/2 activation. J Biol Chem 2003; 278:29317-26. [PMID: 12738790 DOI: 10.1074/jbc.m302368200] [Citation(s) in RCA: 169] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We investigated the role of the endoplasmic reticulum (ER) stress response in intracellular Ca2+ regulation, MAPK activation, and cytoprotection in LLC-PK1 renal epithelial cells in an attempt to identify the mechanisms of protection afforded by ER stress. Cells preconditioned with trans-4,5-dihydroxy-1,2-dithiane, tunicamycin, thapsigargin, or A23187 expressed ER stress proteins and were resistant to subsequent H2O2-induced cell injury. In addition, ER stress preconditioning prevented the increase in intracellular Ca2+ concentration that normally follows H2O2 exposure. Stable transfection of cells with antisense RNA targeted against GRP78 (pkASgrp78 cells) prevented GRP78 induction, disabled the ER stress response, sensitized cells to H2O2-induced injury, and prevented the development of tolerance to H2O2 that normally occurs with preconditioning. ERK and JNK were transiently (30-60 min) phosphorylated in response to H2O2. ER stress-preconditioned cells had more ERK and less JNK phosphorylation than control cells in response to H2O2 exposure. Preincubation with a specific inhibitor of JNK activation or adenoviral infection with a construct that encodes constitutively active MEK1, the upstream activator of ERKs, also protected cells against H2O2 toxicity. In contrast, the pkASgrp78 cells had less ERK and more JNK phosphorylation upon H2O2 exposure. Expression of constitutively active ERK also conferred protection on native as well as pkAS-grp78 cells. These results indicate that GRP78 plays an important role in the ER stress response and cytoprotection. ER stress preconditioning attenuates H2O2-induced cell injury in LLC-PK1 cells by preventing an increase in intracellular Ca2+ concentration, potentiating ERK activation, and decreasing JNK activation. Thus, the ER stress response modulates the balance between ERK and JNK signaling pathways to prevent cell death after oxidative injury. Furthermore, ERK activation is an important downstream effector mechanism for cellular protection by ER stress.
Collapse
Affiliation(s)
- Cheng-Chieh Hung
- Medical Services, Massachusetts General Hospital and Brigham and Women's Hospital, and the Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | | | | |
Collapse
|
180
|
Chijiwa S, Park HR, Furihata K, Ogata M, Endo T, Kuzuyama T, Hayakawa Y, Shin-ya K. Biosynthetic studies of versipelostatin, a novel 17-membered α-tetronic acid involved macrocyclic compound isolated from Streptomyces versipellis. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)01389-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
181
|
Reddy RK, Mao C, Baumeister P, Austin RC, Kaufman RJ, Lee AS. Endoplasmic reticulum chaperone protein GRP78 protects cells from apoptosis induced by topoisomerase inhibitors: role of ATP binding site in suppression of caspase-7 activation. J Biol Chem 2003; 278:20915-24. [PMID: 12665508 DOI: 10.1074/jbc.m212328200] [Citation(s) in RCA: 572] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A large number of correlative studies have established that the activation of the unfolded protein response (UPR) alters the cell's sensitivity to chemotherapeutic agents. Although the induction of the glucose-regulated proteins (GRPs) is commonly used as an indicator for the UPR, the direct role of the GRPs in conferring resistance to DNA damaging agents has not been proven. We report here that without the use of endoplasmic reticulum (ER) stress inducers, specific overexpression of GRP78 results in reduced apoptosis and higher colony survival when challenged with topoisomerase II inhibitors, etoposide and doxorubicin, and topoisomerase I inhibitor, camptothecin. While investigating the mechanism for the GRP78 protective effect against etoposide-induced cell death, we discovered that in contrast to the UPR, GRP78 overexpression does not result in G1 arrest or depletion of topoisomerase II. Caspase-7, an executor caspase that is associated with the ER, is activated by etoposide. We show here that specific expression of GRP78 blocks caspase-7 activation by etoposide both in vivo and in vitro, and this effect can be reversed by addition of dATP in a cell-free system. Recently, it was reported that ectopically expressed GRP78 and caspases-7 and -12 form a complex, thus coupling ER stress to the cell death program. However, the mechanism of how GRP78, a presumably ER lumen protein, can regulate cytosolic effectors of apoptosis is not known. Here we provide evidence that a subpopulation of GRP78 can exist as an ER transmembrane protein, as well as co-localize with caspase-7, as confirmed by fluorescence microscopy. Co-immunoprecipitation studies further reveal endogenous GRP78 constitutively associates with procaspase-7 but not with procaspase-3. Lastly, a GRP78 mutant deleted of its ATP binding domain fails to bind procaspase-7 and loses its protective effect against etoposide-induced apoptosis.
Collapse
Affiliation(s)
- Ramachandra K Reddy
- Department of Biochemistry and Molecular Biology and the USC/Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, California 90089-9176, USA
| | | | | | | | | | | |
Collapse
|
182
|
Abstract
The recent elucidation of the mammalian unfolded protein response pathway has revealed a unique and transcriptionally complex signal transduction pathway that protects cells from a variety of physical and biochemical stresses that can occur during normal development and in disease states. Although the stress conditions are monitored in the endoplasmic reticulum, the beneficial effects of this pathway are extended to other cellular organelles and to the organism itself.
Collapse
Affiliation(s)
- Yanjun Ma
- Department of Tumor Cell Biology, St Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | |
Collapse
|
183
|
Greube A, Rommelspacher H. Isolation and identification of two [(3)H]norharman- ([(3)H]beta-carboline)-binding proteins from rat liver. J Chromatogr B Analyt Technol Biomed Life Sci 2003; 784:155-68. [PMID: 12504194 DOI: 10.1016/s1570-0232(02)00786-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Norharman (9H-pyrido-[3,4-b]indol) represents a member of the mammalian alkaloids with the group name beta-carbolines. In mammals, it exhibits psychotropic and co-mutagenic actions. Highly specific [(3)H]norharman binding sites have been detected in the liver of rats (B(max): 11 pmol mg(-1) protein; K(D): lower nanomolar range). Two [(3)H]norharman binding proteins with apparent molecular masses of 60 and 80 kDa (SDS-PAGE) were isolated from rat liver crude membrane fraction and identified as the enzyme carboxylesterase (EC 3.1.1.1; 60 kDa) and the stress protein glucose-regulated protein 78 (GRP78; 78 kDa). Possible functional consequences of the interaction of norharman with these two proteins are discussed.
Collapse
Affiliation(s)
- Alexa Greube
- Free University of Berlin, Department of Clinical Neurobiology, Ulmenallee 30, D-14050, Berlin, Germany
| | | |
Collapse
|
184
|
Ferrari D, Pinton P, Szabadkai G, Chami M, Campanella M, Pozzan T, Rizzuto R. Endoplasmic reticulum, Bcl-2 and Ca2+ handling in apoptosis. Cell Calcium 2002; 32:413-20. [PMID: 12543100 DOI: 10.1016/s0143416002002014] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the complex signalling interplay that allows extracellular signals to be decoded into activation of apoptotic cell death, Ca(2+) plays a significant role. This is supported not only by evidence linking alterations in Ca(2+) homeostasis to the triggering of apoptotic (and in some cases necrotic) cell death, but also by recent data indicating that a key anti-apoptotic protein, Bcl-2, has a direct effect on ER Ca(2+) handling. We will briefly summarise the first aspect, and describe in more detail these new data, demonstrating that (i) Bcl-2 reduces the state of filling of the ER Ca(2+) store and (ii) this Ca(2+) signalling alteration renders the cells less sensitive to apoptotic stimuli. Overall, these results suggest that calcium homeostasis may represent a pharmacological target in the fundamental pathological process of apoptosis.
Collapse
Affiliation(s)
- D Ferrari
- Department of Experimental Medicine, Section of General Pathology, Telethon Center for Cell Imaging, Interdisciplinary Center for the Study of Inflammation, University of Ferrara, Via Borsari 46, I-44100, Ferrara, Italy
| | | | | | | | | | | | | |
Collapse
|
185
|
Torres LF, Karam SM, Wendling C, Chenard MP, Kershenobich D, Tomasetto C, Rio MC. Trefoil factor 1 (TFF1/pS2) deficiency activates the unfolded protein response. Mol Med 2002; 8:273-282. [PMID: 12359958 DOI: 10.1007/bf03402153] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2002] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The trefoil factor 1 (TFF1/pS2) is a secreted gastrointestinal peptide that is often altered or lost in human gastric cancers. Consistently, mouse TFF1 deficiency leads to antropyloric tumors. MATERIALS AND METHODS To investigate the gene expression alterations in response to the lack of TFF1, we performed differential expression analyses of TFF1 null antropyloric tumors using an array containing 588 cDNAs. RESULTS Using total and enriched probes, 22 genes were found to be up-regulated. The identification of the genes for endoplasmic reticulum (ER)-resident GRP78, ERp72, and p58IPK proteins connected TFF1 deficiency to the unfolded protein response (UPR). Accordingly, CHOP10, a transcription factor induced early in response to ER stress, and the pleiotropic Clusterin, involved in protein folding, were also overexpressed. Northern blot analyses of 8 weeks and 1 year TFF1 null tumors confirmed that GRP78, ERp72, p58IPK, CHOP10, and Clusterin overexpression is a common and permanent feature shared by all TFF1 null antropyloric tumors. Finally, consistent with UPR, ultrastructural analyses showed that tumor rough ER was enlarged and contained dense material, supporting the hypothesis that TFF1 deficiency leads to the accumulation of misfolded proteins in the ER. CONCLUSION Together, our data provide the first evidence of a relationship between a member of the TFF family and the ER machinery. Whereas to date TFF1 is believed to act as an extracellular molecule, our results suggest a possible additional function for TFF1 in protein folding and/or secretion.
Collapse
Affiliation(s)
- Luis-Fernando Torres
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch Cedex, C.U. de Strasbourg, France
| | | | | | | | | | | | | |
Collapse
|
186
|
Ma Y, Hendershot LM. The mammalian endoplasmic reticulum as a sensor for cellular stress. Cell Stress Chaperones 2002; 7:222-9. [PMID: 12380691 PMCID: PMC514821 DOI: 10.1379/1466-1268(2002)007<0222:tmeraa>2.0.co;2] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2002] [Revised: 03/07/2002] [Accepted: 03/07/2002] [Indexed: 01/01/2023] Open
Abstract
The recent elucidation of the mammalian unfolded protein response pathway has revealed a unique and transcriptionally complex signal transduction pathway that protects cells from a variety of physical and biochemical stresses that can occur during normal development and in disease states. Although the stress conditions are monitored in the endoplasmic reticulum, the beneficial effects of this pathway are extended to other cellular organelles and to the organism itself.
Collapse
Affiliation(s)
- Yanjun Ma
- Department of Tumor Cell Biology, St Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | |
Collapse
|
187
|
Vasseur S, Hoffmeister A, Garcia S, Bagnis C, Dagorn JC, Iovanna JL. p8 is critical for tumour development induced by rasV12 mutated protein and E1A oncogene. EMBO Rep 2002; 3:165-70. [PMID: 11818333 PMCID: PMC1083964 DOI: 10.1093/embo-reports/kvf023] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The p8 protein is involved in the cellular stress response of many tissues. Because p8 is overexpressed in many cancers, we investigated whether its expression was required for tumour development. Mouse embryo fibroblasts (MEFs) from p8+/+ and p8-/- animals were transformed with the pBabe-rasV12/E1A retroviral vector, which expresses both the rasV12 mutated protein and the E1A oncogene. As expected, transformed p8+/+ MEFs could form colonies in soft agar. However, transformed p8-/- MEFs could not. In addition, subcutaneous or intraperitoneal injections of transformed p8+/+ MEFs always led to tumour formation in nude mice, but, again, no tumour was observed with transformed p8-/- MEFs. However, restoring p8 expression in transformed p8-/- MEFs before injection led to tumour formation. In the tumours, p8 expression was induced during tumour development. It was concluded that p8 expression in transformed MEFs is necessary for tumour formation, suggesting that the stress-response mechanisms governed by p8 are required for tumour establishment.
Collapse
Affiliation(s)
- Sophie Vasseur
- Centre de Recherche INSERM, EMI 0116, 163 avenue de Luminy, Campus de Luminy, BP 172, F-13009 Marseille, France
| | | | | | | | | | | |
Collapse
|
188
|
Suzuki T, Spitz DR, Gandhi P, Lin HY, Crawford DR. Mammalian resistance to oxidative stress: a comparative analysis. Gene Expr 2002; 10:179-91. [PMID: 12173744 PMCID: PMC5977517 DOI: 10.3727/000000002783992442] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/31/2001] [Indexed: 11/24/2022]
Abstract
Changes in gene expression represent a major protective mechanism, and enforced overexpression of individual genes has been shown to protect cells. However, no large-scale comparison of genes involved in mammalian oxidative stress protection has yet been described. Using filter microarray and restriction fragment differential display technology, hydrogen peroxide (H2O2)-resistant variants of hamster HA-1 fibroblasts and human HL-60 promyelocytes were found to possess a surprising lack of commonality in specific modulated genes with the single exception of catalase, supporting the hypothesis that catalase overexpression is critical for resistance to H2O2. Comparison of two cell lines from the same species (hamster) selected with an exogenous oxidative stressing agent (H2O2) and an endogenous metabolic oxidative stressing agent (95% O2) also revealed little commonality in modulation of specific mRNAs with the exception of glutathione S-transferase enzymes and catalase. Acute oxidative stress in HL-60 led to the modulation of a limited subset of the genes associated with chronic oxidative stress resistance. Overall, these results suggest that mammalian resistance to oxidative and perhaps other stress does not require a significant number of common genes but rather only a limited number of key genes (e.g., catalase in our model systems) in combination with others that are cell type and stress agent specific.
Collapse
Affiliation(s)
- Toshihide Suzuki
- *Laboratory of Forensic Chemistry, Faculty of Pharmaceutical Sciences, Teikyo University, 1091-1 Sagamiko-machi, Tsukui-gun, Kanagawa 199-01Japan
| | - Douglas R. Spitz
- †Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA 52242
| | - Purvee Gandhi
- ‡Center for Immunology and Microbial Disease, The Albany Medical College, Albany, NY 12208
| | - H. Y. Lin
- §Center for Cell Biology and Cancer Research, The Albany Medical College, Albany, NY 12208
| | - Dana R. Crawford
- ‡Center for Immunology and Microbial Disease, The Albany Medical College, Albany, NY 12208
- Address correspondence to Dana R. Crawford, Ph.D., Center for Immunology and Microbial Disease MC-151, The Albany Medical College, Albany, NY 12208. Tel: (518) 262-6652; Fax: (518) 262-6161; E-mail:
| |
Collapse
|
189
|
Dhahbi JM, Cao SX, Mote PL, Rowley BC, Wingo JE, Spindler SR. Postprandial induction of chaperone gene expression is rapid in mice. J Nutr 2002; 132:31-7. [PMID: 11773504 DOI: 10.1093/jn/132.1.31] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Molecular chaperones assist in the biosynthesis and processing of proteins. Most chaperones are induced by physiological stresses. We have shown that dietary energy restriction decreases the mRNA and protein levels of many endoplasmic reticulum chaperones in the livers of mice. Here, we have investigated the response of chaperone mRNA to feeding. Control and 50% energy-restricted C3B10RF1 mice were deprived of food for 24 h, fed, and killed 0, 1.5, 5 or 12 h after feeding. Chaperone mRNAs were strongly induced as early as 1.5 h after feeding in control and energy-restricted mice. The integrated levels of these mRNA over 24 h were significantly lower in energy-restricted mice. The mRNA response to energy intake was mirrored over the course of days in the level of chaperone protein. A similar but smaller response to feeding was found in kidney and muscle. Puromycin and cycloheximide failed to inhibit the feeding response, suggesting that feeding releases chaperone expression from an unstable inhibitor. Studies with dibutyryl-cAMP- and glucagon-supplemented, normal and streptozotocin-diabetic mice suggest that glucagon and insulin may be mediators of the feeding response. Adrenalectomy enhanced the feeding induction, but dexamethasone administration had no effect. Thus, postprandial changes in insulin and glucagon may link chaperone gene expression to feeding, possibly in several tissues including liver.
Collapse
Affiliation(s)
- Joseph M Dhahbi
- Department of Biochemistry, University of California, Riverside, Riverside, CA 92521, USA
| | | | | | | | | | | |
Collapse
|
190
|
Abstract
Nuclear DNA damage and ligation of plasma-membrane death receptors have long been recognized as initial triggers of apoptosis that induce mitochondrial membrane permeabilization (MMP) and/or the direct activation of caspases. Accumulating evidence suggests that other organelles, including the endoplasmic reticulum (ER), lysosomes and the Golgi apparatus, are also major points of integration of pro-apoptotic signalling or damage sensing. Each organelle possesses sensors that detect specific alterations, locally activates signal transduction pathways and emits signals that ensure inter-organellar cross-talk. The ER senses local stress through chaperones, Ca2+-binding proteins and Ca2+ release channels, which might transmit ER Ca2+ responses to mitochondria. The ER also contains several Bcl-2-binding proteins, and Bcl-2 has been reported to exert part of its cytoprotective effect within the ER. Upon membrane destabilization, lysosomes release cathepsins that are endowed with the capacity of triggering MMP. The Golgi apparatus constitutes a privileged site for the generation of the pro-apoptotic mediator ganglioside GD3, facilitates local caspase-2 activation and might serve as a storage organelle for latent death receptors. Intriguingly, most organelle-specific death responses finally lead to either MMP or caspase activation, both of which might function as central integrators of the death pathway, thereby streamlining lysosome-, Golgi- or ER-elicited responses into a common pathway.
Collapse
Affiliation(s)
- K F Ferri
- Centre National de la Recherche Scientifique, UMR 1599, Institut Gustave Roussy, Pavillon de Recherche 1, 39 rue Camille-Desmoulins, F-94805 Villejuif, France
| | | |
Collapse
|
191
|
Abstract
BiP (grp78) is a chaperone protein which can also regulate the unfolded protein response of the cell. Levels of BiP increased in cells infected by the small plaque producing, cell associated, neuroinvasive strains of HSV-1 (SP7, 490) but decreased in cells infected with KOS, a large plaque, attenuated strain. BiP protein synthesis continued early in infection and BiP was sequestered and its degradation was limited during SP7 infection. BiP protein synthesis stopped and the protein was degraded in KOS infected cells. These viral strain dependent differences in BiP concentration may influence other aspects of the viral interaction with the target cell and its host.
Collapse
Affiliation(s)
- H Mao
- Northeastern Ohio Universities College of Medicine, 4209 State Route 44, Box 95, Rootstown, OH 44272, USA
| | | | | |
Collapse
|
192
|
Abstract
A protective mechanism used by cells to adapt to stress of the endoplasmic reticulum (ER) is the induction of members of the glucose-regulated protein (Grp) family. The induction of mammalian Grp proteins in response to ER stress involves a complex network of regulators and novel mechanisms. The elucidation of Grp function and regulation opens up new therapeutic approaches to diseases associated with ER stress and cancer.
Collapse
Affiliation(s)
- A S Lee
- University of Southern California/Norris Comprehensive Cancer Center, Dept of Biochemistry and Molecular Biology, University of Southern California Keck School of Medicine, 1441 Eastlake Avenue, Los Angeles, CA 90089-9176, USA.
| |
Collapse
|
193
|
Bläss S, Union A, Raymackers J, Schumann F, Ungethüm U, Müller-Steinbach S, De Keyser F, Engel JM, Burmester GR. The stress protein BiP is overexpressed and is a major B and T cell target in rheumatoid arthritis. ARTHRITIS AND RHEUMATISM 2001; 44:761-71. [PMID: 11315915 DOI: 10.1002/1529-0131(200104)44:4<761::aid-anr132>3.0.co;2-s] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
OBJECTIVE The ubiquitously expressed intracellular protein formerly designated p68 has been identified as autoantigen at both the antibody and the T cell level in rheumatoid arthritis (RA). METHODS We used 2 independent approaches, Edman degradation and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry, to characterize p68, and we compared its features with those of the endoplasmic reticulum stress protein BiP. RESULTS In synovial sections from RA patients, BiP was highly overexpressed as compared with control sections. Under in vitro stress conditions, BiP was found to translocate to the nucleus and the cell surface. BiP-specific autoantibodies were present in 63% of 400 RA patients, in 7% of 200 patients with other rheumatic diseases, and in none of the healthy subjects. Thus, BiP-specific autoantibodies represent a new diagnostic marker in RA. Furthermore, we found that BiP-specific T cell reactivity was altered in RA. In healthy individuals and patients with other rheumatic diseases, BiP-reactive T cells were undetectable. In RA, overt T cell reactivity to BiP was observed or could be induced by specifically blocking antigen presentation to potentially regulatory T cells. CONCLUSION Since overexpression of BiP has been shown to decrease the sensitivity of cells to killing by cytotoxic T cells, BiP overexpression and BiP-specific autoimmunity may be involved in the pathogenesis of RA.
Collapse
Affiliation(s)
- S Bläss
- Department of Rheumatology and Clinical Immunology, Charité University Hospital, Berlin, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
194
|
Wisnewski AV, Srivastava R, Herick C, Xu L, Lemus R, Cain H, Magoski NM, Karol MH, Bottomly K, Redlich CA. Identification of human lung and skin proteins conjugated with hexamethylene diisocyanate in vitro and in vivo. Am J Respir Crit Care Med 2000; 162:2330-6. [PMID: 11112159 DOI: 10.1164/ajrccm.162.6.2002086] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Diisocyanates are asthma-causing chemicals used in the commercial production of polyurethane. We have previously shown that human lung epithelial cell proteins can become conjugated with hexamethylene diisocyanate (HDI) and may be biologically important in diisocyanate-induced asthma. The objective of this study was to identify specific human lung and skin proteins that become conjugated with diisocyanate after in vitro and in vivo exposure. Following in vitro exposure of human airway epithelial cells (A549), keratin 18, the 78-kD glucose-regulated protein, trans-1, 2-dihyrobenzene-1,2-diol dehydrogenase, and actin were identified as prominent diisocyanate-conjugated proteins through use of a combination of immunocytochemical and mass spectrometric techniques. Following in vivo inhalation of an HDI aerosol, keratin 18 was also identified as the predominant diisocyanate-conjugated protein in human endobronchial biopsy samples, whereas albumin was the predominant diisocyanate-conjugated protein in bronchoalveolar lavage fluid. Keratin was also identified as a predominant diisocyanate-conjugated protein in human skin biopsy samples after epicutaneous exposure to liquid-phase HDI, although the major skin diisocyanate-conjugated protein (56-kD) differed from the predominant lung diisocyanate-conjugated keratin (47-kD). The data from this study identify keratin and other proteins as potential "carriers" for diisocyanates in vivo, and suggest that HDI conjugation of these proteins may play a role in the pathogenesis of diisocyanate-induced asthma.
Collapse
Affiliation(s)
- A V Wisnewski
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
195
|
Abstract
Interferon plays a critical role in the host's natural defense against viral infections and in their treatment. It is the only therapy for hepatitis C virus (HCV) infection; however, many virus isolates are resistant. Several HCV proteins have been shown to possess properties that enable the virus to evade the interferon-mediated cellular antiviral responses.
Collapse
Affiliation(s)
- D R Taylor
- Department of Molecular Microbiology and Immunology, University of Southern California, School of Medicine, 2011 Zonal Avenue, Los Angeles, CA 90089, USA
| | | | | |
Collapse
|
196
|
Leahy KP, Crawford DR. adapt78 protects cells against stress damage and suppresses cell growth. Arch Biochem Biophys 2000; 379:221-8. [PMID: 10898938 DOI: 10.1006/abbi.2000.1897] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
We have previously identified several genes whose RNA products are induced in HA-1 hamster cells under conditions where a cytoprotective adaptive response is observed. One of these genes, designated adapt78, was found to have a human homolog with some homology to glucose-regulated protein 78 (Grp78). We subsequently determined that adapt78 and grp78 mRNAs are induced by the same stress agents and conclude that adapt78 is a stress-response gene and putative new member of the grp stress gene family. Here we extend these studies to assess the effect of overexpressing adapt78 on stress protection and growth arrest. HA-1 cells stably transfected with adapt78 cDNA were found to exhibit significantly reduced calcium- and hydrogen peroxide-mediated cytotoxicity as compared with control transfectants. In addition, adapt78 stable overexpressors exhibited significantly reduced cell growth. Both cytoprotection and growth arrest accompanied only modest overexpression of adapt78. Flow cytometry revealed that the growth arrest occurred in G(1)-phase. Immunoflourescent analysis revealed that Adapt78 protein exhibits significant perinuclear staining suggestive of endoplasmic reticulum localization in addition to cytoplasmic localization. These data indicate that adapt78 is both cytoprotective and growth suppressive and that these effects may be mediated by Adapt78 protein at the endoplasmic reticulum.
Collapse
Affiliation(s)
- K P Leahy
- Center for Immunology and Microbial Disease, The Albany Medical College, Albany, New York 12208, USA
| | | |
Collapse
|
197
|
Jackson KM, DeLeon M, Sistonen L, Verret CR. Heat-shocked A20 lymphoma cells fail to induce degranulation of cytotoxic T lymphocytes: possible mechanism of resistance. Cell Immunol 2000; 203:12-8. [PMID: 10915557 DOI: 10.1006/cimm.2000.1669] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A20 lymphoma cells were subjected to heat shock for 2 h at 42 and 43 +/- 0.1 degrees C and then evaluated at 37 degrees C for sensitivity to lysis by intact allo-specific cytotoxic T lymphocytes (CTLs), perforin-containing granules isolated from CTLs, and Fas-mediated apoptosis. Heat shock at 42 degrees C caused little change in sensitivity of the lymphoma cell line to lysis by intact CTLs or their isolated cytotoxic granules, but caused increased sensitivity to Fas-mediated apoptosis. However, A20 cells shocked at 43 degrees C declined significantly in sensitivity to lysis by intact CTLs, while remaining very sensitive to perforin granules and to Fas-mediated apoptosis. Expression of the inducible heat shock protein was observed in A20 cells incubated at 43 degrees C, but not in those incubated at 42 degrees C, suggesting a role for heat shock proteins. Furthermore, A20 cells shocked at 43 degrees C did not provoke degranulation and secretion of granzymes by antigen-specific CTLs, although formation of CTL-target conjugates and levels of MHC class I molecules remained unchanged. These observations demonstrate that hyperthermia or febrile conditions may reduce susceptibility of target cells to CTL attack due to failure of antigen presentation and the inability of CTLs to recognize heat stressed targets, thus enabling targets to escape CTL attack.
Collapse
Affiliation(s)
- K M Jackson
- Department of Chemistry, Clark Atlanta University, 223 James P. Brawley Drive, Atlanta, Georgia 30314, USA
| | | | | | | |
Collapse
|
198
|
Abstract
Preparations of stress protein gp96 from tumor cells are active as tumor vaccines by eliciting immune responses against mixtures of individual tumor peptide antigens which are complexed to gp96. Due to the individual antigenicity of tumors, a vaccine consisting of tumor-derived gp96 has to be prepared individually for each patient from autologous tumor tissue. So far, gp96 expression by human tumors has not been analyzed. Here, we report stable and mostly homogenous expression of gp96 by colorectal cancer, which was enhanced compared to surrounding tumor stroma in 70% to 80% of colorectal cancer specimens. Fewer non-metastatic than metastatic primary cancer specimens showed enhanced gp96 expression. Glucose deprivation increased gp96 protein and RNA expression in the human colon cancer cell line HT-29 in accordance with the role of gp96 as a glucose-regulated stress protein. Additionally, TNF-alpha, interferons and other cytokines induced an increase of gp96 RNA expression in HT-29 cells, suggesting that gp96 expression by colorectal cancer cells can be influenced by different methods of immunomodulation. The stable and homogenous expression of gp96 in 19 primary and metastatic colorectal cancer specimens and the up-regulation of gp96 in colon cancer cells by glucose deprivation point to an essential role of this stress protein in colorectal cancer, presumably by protecting against hostile conditions of the tumor micro-environment like glucose deprivation. In view of these results, loss of gp96 expression by colorectal cancer cells as an immune escape mechanism is unlikely.
Collapse
Affiliation(s)
- M Heike
- I. Medizinische Klinik und Poliklinik, Johannes Gutenberg-Universität Mainz, Germany.
| | | | | | | |
Collapse
|
199
|
Miyake H, Hara I, Arakawa S, Kamidono S. Stress protein GRP78 prevents apoptosis induced by calcium ionophore, ionomycin, but not by glycosylation inhibitor, tunicamycin, in human prostate cancer cells. J Cell Biochem 2000; 77:396-408. [PMID: 10760948 DOI: 10.1002/(sici)1097-4644(20000601)77:3<396::aid-jcb5>3.0.co;2-5] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
GRP78 induction has recently been shown to play a critical role in maintaining cell viability against several kinds of stress, including depletion of endoplasmic reticulum Ca(2+) and accumulation of unglycosylated proteins, under specific experimental conditions. However, the functional significance of GRP78 induction after stressful treatment has not been well defined. This article characterizes the different biological features associated with GRP78 induction by two kinds of stress agents, calcium ionophore, ionomycin (IM), and glycosylation inhibitor, tunicamycin (TM), focusing on the association with apoptosis in human prostate cancer cells. Both IM and TM treatment resulted in marked induction of GRP78 transcription in androgen-dependent prostate cancer LNCaP cells maintained in medium without androgen, but not in medium containing androgen, as measured by Northern blotting and nuclear run-off assays. After pretreatment with tumor necrosis factor-alpha, which has potent cytotoxic effects on LNCaP cells, both IM and TM could induce substantial increases in GRP78 transcription in LNCaP cells, even in medium containing androgen. Under both experimental conditions described, DNA fragmentation assays showed a direct correlation between the onset of apoptosis in LNCaP cells after IM treatment and the initiation of GRP78 transcript induction, while induction of GRP78 expression preceded TM-induced apoptosis. To elucidate the functional differences of GRP78 induction by IM and TM, an antisense oligodeoxynucleotide (ODN) targeted against the grp78 gene was designed to reduce GRP78 expression in a sequence-specific and dose-dependent manner. Antisense GRP78 ODN treatment substantially enhanced apoptosis of LNCaP cells induced by IM compared with mismatch control ODN treatment, whereas no marked differences were observed in apoptotic features induced by TM with antisense GRP78 and mismatch control ODN treatment. Studies of additional androgen-independent prostate cancer PC3 cells also demonstrated a correlation between GRP78 induction and resistance to apoptosis after IM treatment, but not after TM treatment. These findings suggest that there are at least two GRP78 signaling pathways, which play different roles in resistance against stress-induced apoptosis.
Collapse
Affiliation(s)
- H Miyake
- Department of Urology, Kobe University School of Medicine, Kobe 650-0017, Japan
| | | | | | | |
Collapse
|
200
|
Dressel R, Elsner L, Quentin T, Walter L, Günther E. Heat shock protein 70 is able to prevent heat shock-induced resistance of target cells to CTL. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:2362-71. [PMID: 10679071 DOI: 10.4049/jimmunol.164.5.2362] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Heat shock or transfection with heat shock protein 70 (Hsp70) genes has been shown to protect tumor cell lines against immune mechanisms of cytotoxicity. We have reported previously that heat shock confers resistance to CTL in the rat myeloma cell line Y3 that is Hsp70 defective. Evidence is now presented that Hsp70 is able to prevent the induction of the resistant phenotype. In Con A-stimulated lymphocytes and in lymphocyte x Y3 somatic cell hybrid clones a severe, non-Hsp70-inducing heat shock elicits resistance to CTL in contrast to a heat shock that results in Hsp70 expression. Thus, Hsp70 expression appears to be negatively associated with the development of resistance. Furthermore, loading of Y3 cells with recombinant Hsp70 protein before heat shock is able to prevent resistance. Because apoptosis induced in Y3 cells by heat shock is not affected, Hsp70 appears to interfere selectively with the CTL-induced lethal pathway that is found to be calcium but not caspase dependent. It is suggested that after heat shock Hsp70 enhances the CTL-induced apoptotic pathway by chaperoning certain proteins in the target cell that are involved in the execution of cell death. Thus, although shown to confer protection against many cytotoxic mechanisms, Hsp70 does not appear to be generally cytoprotective. This observation could also be of relevance when interpreting the effectiveness of tumor immunity.
Collapse
Affiliation(s)
- R Dressel
- Division of Immunogenetics, University of Göttingen, Göttingen, Germany
| | | | | | | | | |
Collapse
|