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Li C, Menoret A, Farragher C, Ouyang Z, Bonin C, Holvoet P, Vella AT, Zhou B. Single cell transcriptomics based-MacSpectrum reveals novel macrophage activation signatures in diseases. JCI Insight 2019; 5:126453. [PMID: 30990466 DOI: 10.1172/jci.insight.126453] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Adipose tissue macrophages (ATM) are crucial for maintaining adipose tissue homeostasis and mediating obesity-induced metabolic abnormalities, including prediabetic conditions and type 2 diabetes mellitus. Despite their key functions in regulating adipose tissue metabolic and immunologic homeostasis under normal and obese conditions, a high-resolution transcriptome annotation system that can capture ATM multifaceted activation profiles has not yet been developed. This is primarily attributed to the complexity of their differentiation/activation process in adipose tissue and their diverse activation profiles in response to microenvironmental cues. Although the concept of multifaceted macrophage action is well-accepted, no current model precisely depicts their dynamically regulated in vivo features. To address this knowledge gap, we generated single-cell transcriptome data from primary bone marrow-derived macrophages under polarizing and non-polarizing conditions to develop new high-resolution algorithms. The outcome was creation of a two-index platform, MacSpectrum (https://macspectrum.uconn.edu), that enables comprehensive high-resolution mapping of macrophage activation states from diverse mixed cell populations. MacSpectrum captured dynamic transitions of macrophage subpopulations under both in vitro and in vivo conditions. Importantly, MacSpectrum revealed unique "signature" gene sets in ATMs and circulating monocytes that displayed significant correlation with BMI and homeostasis model assessment of insulin resistance (HOMA-IR) in obese human patients. Thus, MacSpectrum provides unprecedented resolution to decode macrophage heterogeneity and will open new areas of clinical translation.
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Affiliation(s)
- Chuan Li
- Department of Immunology, School of Medicine, University of Connecticut, Farmington, Connecticut, USA
| | - Antoine Menoret
- Department of Immunology, School of Medicine, University of Connecticut, Farmington, Connecticut, USA.,Institute for Systems Genomics, University of Connecticut, Farmington, Connecticut, USA
| | - Cullen Farragher
- College of Liberal Arts and Sciences, University of Connecticut, Storrs, Connecticut, USA
| | - Zhengqing Ouyang
- Institute for Systems Genomics, University of Connecticut, Farmington, Connecticut, USA.,The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA.,Department of Biomedical Engineering, University of Connecticut, Storrs, Connecticut, USA.,Department of Genetics and Genome Sciences, University of Connecticut, Farmington, Connecticut, USA
| | - Christopher Bonin
- School of Medicine, University of Connecticut, Farmington, Connecticut, USA
| | - Paul Holvoet
- Experimental Cardiology, Department of Cardiovascular Sciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Anthony T Vella
- Department of Immunology, School of Medicine, University of Connecticut, Farmington, Connecticut, USA
| | - Beiyan Zhou
- Department of Immunology, School of Medicine, University of Connecticut, Farmington, Connecticut, USA.,Institute for Systems Genomics, University of Connecticut, Farmington, Connecticut, USA
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2
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Mizuno R, Chatterji P, Andres S, Hamilton K, Simon L, Foley SW, Jeganathan A, Gregory BD, Madison B, Rustgi AK. Differential Regulation of LET-7 by LIN28B Isoform-Specific Functions. Mol Cancer Res 2018; 16:403-416. [PMID: 29330293 DOI: 10.1158/1541-7786.mcr-17-0514] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/07/2017] [Accepted: 11/29/2017] [Indexed: 12/30/2022]
Abstract
The RNA-binding protein LIN28B plays an important role in development, stem cell biology, and tumorigenesis. LIN28B has two isoforms: the LIN28B-long and -short isoforms. Although studies have revealed the functions of the LIN28B-long isoform in tumorigenesis, the role of the LIN28B-short isoform remains unclear and represents a major gap in the field. The LIN28B-long and -short isoforms are expressed in a subset of human colorectal cancers and adjacent normal colonic mucosa, respectively. To elucidate the functional and mechanistic aspects of these isoforms, colorectal cancer cells (Caco-2 and LoVo) were generated to either express no LIN28B or the -short or -long isoform. Interestingly, the long isoform suppressed LET-7 expression and activated canonical RAS/ERK signaling, whereas the short isoform did not. The LIN28B-long isoform-expressing cells demonstrated increased drug resistance to 5-fluorouracil and cisplatin through the upregulation of ERCC1, a DNA repair gene, in a LET-7-dependent manner. The LIN28B-short isoform preserved its ability to bind pre-let-7, without inhibiting the maturation of LET-7, and competed with the LIN28B-long isoform for binding to pre-let-7 Coexpression of the short isoform in the LIN28B-long isoform-expressing cells rescued the phenotypes induced by the LIN28B-long isoform.Implications: This study demonstrates the differential antagonistic functions of the LIN28B-short isoform against the LIN28B-long isoform through an inability to degrade LET-7, which leads to the novel premise that the short isoform may serve to counterbalance the long isoform during normal colonic epithelial homeostasis, but its downregulation during colonic carcinogenesis may reveal the protumorigenic effects of the long isoform. Mol Cancer Res; 16(3); 403-16. ©2018 AACR.
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Affiliation(s)
- Rei Mizuno
- Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Priya Chatterji
- Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sarah Andres
- Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kathryn Hamilton
- Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Lauren Simon
- Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Shawn W Foley
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Arjun Jeganathan
- Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Brian D Gregory
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Blair Madison
- Division of Gastroenterology, Department of Medicine, Washington University, St. Louis, Missouri
| | - Anil K Rustgi
- Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. .,Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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Polymorphism in ERCC1 confers susceptibility of coronary artery disease and severity of coronary artery atherosclerosis in a Chinese Han population. Sci Rep 2017; 7:6407. [PMID: 28743890 PMCID: PMC5526898 DOI: 10.1038/s41598-017-06732-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 06/15/2017] [Indexed: 11/08/2022] Open
Abstract
Excision repair cross-complementing 1 (ERCC1) gene encodes ERCC1 protein, which is mainly responsible for the repair of DNA damage in different diseases including coronary artery atherosclerosis by acting as a rate-limiting element in nucleotide excision repair (NER). Using a three-stage case-control study with 3037 coronary artery disease (CAD) patients and 3002 controls, we investigated associations of three single nucleotide polymorphisms (SNPs) with CAD risk and severity of coronary artery atherosclerosis in Chinese Han population. In the discovery set, the variant allele T of rs11615 was significantly associated with higher CAD risk (adjusted OR = 1.27, P = 0.006) and severity of coronary artery atherosclerosis (adjusted OR = 1.54, P = 0.003). These associations were more remarkable in the merged set (adjusted OR = 1.23, P = 8 × 10-6 for CAD risk; adjusted OR = 1.36, P = 4.3 × 10-5 for severity of coronary artery atherosclerosis). And the expression level of ERCC1 was significantly higher in CAD cases than controls. Multiplicative interactions among SNP rs11615, alcohol drinking, history of T2DM, and history of hyperlipidemia could increase 5.06-fold risk of CAD (P = 1.59 × 10-9). No significant association of rs2298881 and rs3212986 with CAD risk was identified. Taken together, SNP rs11615 in ERCC1 gene might confer susceptibility to CAD and severity of coronary atherosclerosis in a Chinese Han population.
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Qiao Y, Tomonaga S, Matsui T, Funaba M. Modulation of the cellular content of metabolites in adipocytes by insulin. Mol Cell Endocrinol 2016; 424:71-80. [PMID: 26811873 DOI: 10.1016/j.mce.2016.01.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 01/18/2016] [Accepted: 01/19/2016] [Indexed: 12/29/2022]
Abstract
Although the insulin-mediated cell signaling pathway has been extensively examined, changes in the cellular content of metabolites currently remain unclear. We herein examined metabolite contents in 3T3-L1 adipocytes treated with insulin using a metabolomic analysis. Fifty-four compounds were detected, and the contents of metabolites from the citric acid cycle increased in response to the insulin treatment for 4 h, which was sensitive to U0126 and LY294002, inhibitors for mitogen-activated protein kinase kinase-1 and phosphoinositide 3-kinase, respectively. The cellular contents of fumaric acid and malic acid were increased more by insulin than those of citric acid and succinic acid. Time-course changes in metabolites from the citric acid cycle exhibited oscillations with a 2-h cycle. A metabolic pathway analysis also indicated that insulin affected the metabolism of alanine, aspartate and glutamate, as well as that of arginine and proline. The contents of free amino acids were slightly decreased by the insulin treatment, while the co-treatment with U0126 and LY294002 abrogated these insulin-mediated decreases. The present study revealed the unexpected accumulation of citric acid cycle metabolites in adipocytes by insulin. Our results indicate the usefulness of metabolomic analyses for obtaining a more comprehensive understanding of the regulation of metabolic pathways in cell-culture systems.
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Affiliation(s)
- Yuhang Qiao
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Shozo Tomonaga
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Tohru Matsui
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Masayuki Funaba
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
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Wu J, Starr S. Low-fidelity compensatory backup alternative DNA repair pathways may unify current carcinogenesis theories. Future Oncol 2015; 10:1239-53. [PMID: 24947263 DOI: 10.2217/fon.13.272] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The somatic mutation carcinogenesis theory has dominated for decades. The alternative theory, tissue organization field theory, argues that the development of cancer is determined by the surrounding microenvironment. However, neither theory can explain all features of cancer. As cancers share the features of uncontrolled proliferation and genomic instability, they are likely to have the same pathogenesis. It has been found that various DNA repair pathways within a cell crosstalk with one another, forming a DNA repair network. When one DNA repair pathways is defective, the others may work as compensatory backups. The latter pathways are explored for synthetic lethal anticancer therapy. In this article, we extend the concept of compensatory alternative DNA repair to unify the theories. We propose that the microenvironmental stress can activate low-fidelity compensatory alternative DNA repair, causing mutations. If the mutation occurs to a DNA repair gene, this secondarily mutated gene can lead to even more mutated genes, including those related to other DNA repair pathways, eventually destabilizing the genome. Therefore, the low-fidelity compensatory alternative DNA repair may mediate microenvironment-dependent carcinogenesis. The proposal seems consistent with the view of evolution: the environmental stress causes mutations to adapt to the changing environment.
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Affiliation(s)
- Jiaxi Wu
- Central Laboratories, Xuhui Central Hospital, Shanghai Clinical Research Center, Chinese Academy of Sciences, 966 Middle Huaihai Road, Shanghai 200031, China
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Jeong YH, Lee CK, Jo K, Hwang SH, Cha J, Lee JW, Yun M, Cho A. Correlation Analysis and Prognostic Impact of (18)F-FDG PET and Excision Repair Cross-Complementation Group 1 (ERCC-1) Expression in Non-Small Cell Lung Cancer. Nucl Med Mol Imaging 2014; 49:108-14. [PMID: 26085855 DOI: 10.1007/s13139-014-0304-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/20/2014] [Accepted: 10/22/2014] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The aim of this study was to determine the relationship between [(18)]-2-fluoro-2-deoxy-D-glucose (FDG) uptake and excision repair cross-complementation group 1 (ERCC-1) expression and to evaluate the prognostic effect of these two factors in resectable non-small cell lung cancer (NSCLC) patients. METHODS We retrospectively reviewed 212 patients with resectable NSCLC who underwent FDG positron emission tomography/computed tomography (PET/CT) scan for cancer staging and ERCC-1 expression analysis between January 2008 to December 2011. All patients were then followed-up for survival analysis. Semiquantitative evaluation of ERCC-1 was performed with the H-scoring system and was correlated with maximum standardized uptake value (SUVmax) of NSCLC. Univariate and multivariate analyses were performed to evaluate for FDG uptake and ERCC-1 expression predicting overall survival. RESULTS In 212 patients (139 male, median age 68 ± 9.11), 112 patients had ERCC-positive tumors and 100 patients had ERCC-negative tumors. There was no significant difference in SUVmax between ERCC-1-positive tumors (8.02 ± 5.40) and ERCC-1-negative tumors (7.57 ± 6.56, p = 0.584). All patients were followed-up for a median of 40.5 months (95 % confidence interval [CI], 38.5-42.2 months). Univariate analysis and multivariate analysis for all patients showed that both ERCC-1 expression (hazard ratio [HR], 2.78; 95 % CI, 1.20-6.47) and FDG uptake (HR, 4.50; 95 % CI, 2.07-9.77) independently predicted overall survival. CONCLUSIONS We have found no statistical correlation between FDG uptake and ERCC-1 expression in NSCLC. However, both higher FDG uptake and positive ERCC-1 expression are independent predictive markers of prognosis, suggesting that both should be obtained during patient workup.
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Affiliation(s)
- Yong Hyu Jeong
- Department of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, 120-752 Seoul South Korea
| | - Choong-Kun Lee
- Department of Internal Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, 120-752 Seoul South Korea
| | - Kwanhyeong Jo
- Department of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, 120-752 Seoul South Korea
| | - Sang Hyun Hwang
- Department of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, 120-752 Seoul South Korea
| | - Jongtae Cha
- Department of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, 120-752 Seoul South Korea
| | - Jeong Won Lee
- Department of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, 120-752 Seoul South Korea
| | - Mijin Yun
- Department of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, 120-752 Seoul South Korea
| | - Arthur Cho
- Department of Nuclear Medicine, Severance Hospital, Yonsei University College of Medicine, 50-1 Yonsei-Ro, Seodaemun-Gu, 120-752 Seoul South Korea
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Doubling down on the PI3K-AKT-mTOR pathway enhances the antitumor efficacy of PARP inhibitor in triple negative breast cancer model beyond BRCA-ness. Neoplasia 2014; 16:43-72. [PMID: 24563619 DOI: 10.1593/neo.131694] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 12/05/2013] [Accepted: 12/19/2013] [Indexed: 12/21/2022] Open
Abstract
Phosphoinositide 3-kinase (PI3K) pathway, in addition to its pro-proliferative and antiapoptotic effects on tumor cells, contributes to DNA damage repair (DDR). We hypothesized that GDC-0980, a dual PI3K-mammalian target of rapamycin (mTOR) inhibitor, would induce an efficient antitumor effect in BRCA-competent triple negative breast cancer (TNBC) model when combined with ABT888 and carboplatin. Mechanism-based in vitro studies demonstrated that GDC-0980 treatment alone or in combination led to DNA damage (increased pγH2AX(S139); Western blot, immunofluorescence), gain in poly ADP-ribose (PAR), and a subsequent sensitization of BRCA-competent TNBC cells to ABT888 plus carboplatin with a time-dependent 1) decrease in proliferation signals (pAKTT308/S473, pP70S6KT421/S424, pS6RPS235/236), PAR/poly(ADP-ribose) polymerase (PARP) ratios, PAR/pγH2AX ratios, live/dead cell ratios, cell cycle progression, and three-dimensional clonogenic growths and 2) increase in apoptosis markers (cleaved caspases 3 and 9, a pro-apoptotic BH3-only of Bcl-2 family (BIM), cleaved PARP, annexin V). The combination was effective in vitro in BRCA-wild-type PIK3CA-H1047R-mutated BT20 and PTEN-null HCC70 cells. The combination blocked the growth of established xenograft tumors by 80% to 90% with a concomitant decrease in tumor Ki67, CD31, phosphorylated vascular endothelial growth factor receptor, pS6RPS235/236, and p4EBP1T37/46 as well as an increase in cleaved caspase 3 immunohistochemistry (IHC) levels. Interestingly, a combination with GDC-0941, a pan-PI3K inhibitor, failed to block the tumor growth in MDA-MB231. Results demonstrate that the dual inhibition of PI3K and mTOR regulates DDR. In a BRCA-competent model, GDC-0980 enhanced the antitumor activity of ABT888 plus carboplatin by inhibiting both tumor cell proliferation and tumor-induced angiogenesis along with an increase in the tumor cell apoptosis. This is the first mechanism-based study to demonstrate the integral role of the PI3K-AKT-mTOR pathway in DDR-mediated antitumor action of PARP inhibitor in TNBC.
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Cisplatin regulates the MAPK kinase pathway to induce increased expression of DNA repair gene ERCC1 and increase melanoma chemoresistance. Oncogene 2011; 31:2412-22. [PMID: 21996734 DOI: 10.1038/onc.2011.426] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The incidence of malignant melanoma is growing rapidly worldwide and there is still no effective therapy for metastatic disease. Melanoma is the second most common cancer among young adults in the UK, where incidence rates have more than quadrupled since the 1970s. Increased expression of a number of DNA repair genes has been reported in melanoma and this likely contributes to its extreme resistance to conventional DNA-damaging chemotherapeutics. One such chemotherapeutic that is effective against a range of other cancers, but not melanoma, is cisplatin. The DNA repair proteins ERCC1 and XPF are needed to remove cisplatin-induced DNA damage and we have investigated the response of these proteins to cisplatin in melanoma. The expression of both genes is induced by cisplatin. Use of a MEK inhibitor showed that ERCC1, but not XPF induction was regulated by the mitogen-activated protein kinase (MAPK) pathway, with reduction in expression of DUSP6, the phosphatase that inactivates the extracellular signal-regulated kinase (ERK), being particularly important. DUSP6 overexpression prevented cisplatin induction of both ERCC1 and XPF, resulting in increased sensitivity to cisplatin. A novel ERCC1 mRNA was found that initiated upstream of the normal transcription initiation site, and was strongly regulated by both cisplatin and the MAPK pathway and its role in cisplatin resistance merits further study. The cisplatin induction of ERCC1 and XPF provides important insights into the resistance of melanoma to DNA-damaging chemotherapeutics, which is one of the major obstacles to melanoma treatment.
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Loriot Y, Mordant P, Deutsch E, Olaussen KA, Soria JC. Are RAS mutations predictive markers of resistance to standard chemotherapy? Nat Rev Clin Oncol 2009; 6:528-34. [DOI: 10.1038/nrclinonc.2009.106] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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10
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Cai BX, Luo D, Lin XF, Gao J. Compound K suppresses ultraviolet radiation-induced apoptosis by inducing DNA repair in human keratinocytes. Arch Pharm Res 2008; 31:1483-8. [DOI: 10.1007/s12272-001-2134-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2008] [Revised: 10/20/2008] [Accepted: 10/24/2008] [Indexed: 01/24/2023]
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Role of extracellular signal-regulated kinase (ERK) signaling in nucleotide excision repair and genotoxicity in response to As(III) and Pb(II). PURE APPL CHEM 2008. [DOI: 10.1351/pac200880122735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Arsenic and lead can induce genetic injuries and epigenetic signaling pathways in cultured mammalian cells. To test whether signaling pathways affect the extent of genetic injuries, we explored the impacts of extracellular signal-regulated kinase 1 and 2 (ERK) on nucleotide excision repair (NER), cytotoxicity, and genotoxicity following sodium arsenite [As(III)] and lead acetate [Pb(II)]. Sustained ERK activation was observed in human cells exposed to As(III) and Pb(II). As(III) inhibited the cellular NER synthesis capability; conversely, Pb(II) stimulated it. ERK activation contributed to the As(III)-induced NER inhibition and micronucleus formation. In contrast, this signal was required for inducing cellular NER activity and preventing mutagenesis following Pb(II). ERK activation by Pb(II) was dependent on protein kinase C (PKCα) that also exhibited anti-mutagenicity. Enforced expression of ERK signaling markedly elevated the cellular NER activity, which was suppressed by As(III). Nonetheless, ERK activation could counteract the cytotoxicity caused by these two metals. Together, the results indicate that pro-survival ERK signaling exhibits dual and opposing impacts on NER process following As(III) and Pb(II) exposures. The findings also suggest that ERK is an important epigenetic signaling in the determination of metal genotoxicity.
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Weidhaas JB, Eisenmann DM, Holub JM, Nallur SV. A Conserved RAS/Mitogen-Activated Protein Kinase Pathway Regulates DNA Damage–Induced Cell Death Postirradiation in Radelegans. Cancer Res 2006; 66:10434-8. [PMID: 17079464 DOI: 10.1158/0008-5472.can-06-2182] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although the epidermal growth factor receptor (EGFR) signaling pathway is overactive in more than half of human cancers and mediates resistance to cytotoxic therapy, the molecular mechanisms of EGFR pathway-mediated resistance have remained elusive in cancer research. This difficulty partly stems from the lack of tissue models enabling clear separation of the many forms of cell death that the downstream signaling pathways of EGFR affect. We have created a model in Caenorhabditis elegans of radiation-induced reproductive cell death ("Radelegans") in isolation of all other forms of cell death. We have employed Radelegans to genetically define the role of the EGFR signaling pathway in protection from reproductive cell death, the primary form of tumor stem or clonogen cell death postirradiation. We have found that the RAS/mitogen-activated protein kinase (MAPK) downstream signal transduction pathway of EGFR is critical for protection from reproductive cell death in Radelegans. In addition, we have shown that RAS/MAPK pathway signaling is genetically linear with the DNA damage response pathway and acts downstream of the DNA damage checkpoint in the radioresponse, implicating this pathway in DNA repair post-cytotoxic therapy. These findings support the hypothesis that enhanced repair is a mechanism of RAS/MAPK pathway-mediated resistance to cytotoxic therapy through its interaction with the DNA damage response pathway postirradiation. We postulate that these findings also help explain why current treatment strategies, based on the presumption that tumors have ineffective repair compared with normal tissues, are ineffective in EGFR/RAS/MAPK pathway-mediated tumors. Radelegans is a platform to further define the genetic basis of the radiation response in tissues.
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Affiliation(s)
- Joanne B Weidhaas
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520-8040, USA.
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Li JP, Lin JC, Yang JL. ERK activation in arsenite-treated G1-enriched CL3 cells contributes to survival, DNA repair inhibition, and micronucleus formation. Toxicol Sci 2005; 89:164-72. [PMID: 16207941 DOI: 10.1093/toxsci/kfj004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Arsenite is known to induce chromosomal damage and extracellular signal-regulated kinases 1/2 (ERK) signaling transduction pathway. Arsenite also perturbs mitotic spindle and induces G2/M prolongation, leading to genomic instability. However, little is known concerning whether G1 phase is susceptible to arsenite in causing genomic instability and ERK activation. In this study, we investigate the roles of ERK activation in survival, micronucleus formation, and nucleotide excision repair (NER) synthesis in arsenite-treated G1-enriched CL3 human non-small-cell lung carcinoma cells. We found that G1 was the most insensitive phase to arsenite cytotoxicity, yet it was highly susceptible to arsenite in micronucleus induction. After arsenite exposure, the G1 cells exhibited a marked retard in the formation of binucleated cells when they were cultured in cytochalasin B, an inhibitor of cytokinesis, suggesting that arsenite delays the cell cycle progression. Arsenite activated sustained-ERK signal in G1 cells whose suppression further decreased cell proliferation and survival and could lower the micronucleus induction. The NER synthesis activity of G1 cells was inhibited by arsenite as a function of the extent of ERK activation. Intriguingly, blockage of ERK activation recovered NER synthesis activity in the arsenite-treated G1 cells. Together, these results suggest that ERK activation in arsenite-treated G1 cells counteracts cytotoxicity and contributes to genomic instability via NER synthesis inhibition and micronucleus induction.
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Affiliation(s)
- Ju-Pi Li
- Molecular Carcinogenesis Laboratory, Institute of Biotechnology and Department of Life Sciences, National Tsing Hua University, Hsinchu 300, Taiwan
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Kang S, Song J, Kang J, Kang H, Lee D, Lee Y, Park D. Suppression of the alpha-isoform of class II phosphoinositide 3-kinase gene expression leads to apoptotic cell death. Biochem Biophys Res Commun 2005; 329:6-10. [PMID: 15721265 DOI: 10.1016/j.bbrc.2005.01.091] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2005] [Indexed: 11/24/2022]
Abstract
Phosphoinositide 3-kinases (PI3Ks) have known to be key enzymes activating intracellular signaling molecules when a number of growth factors bind to their cell surface receptors. PI3Ks are divided into three classes (I, II, and III) and enzymes of each class have different tissue-specificities and physiological functions. Class II PI3Ks consist of three isoforms (alpha,beta,gamma). Although the alpha-isoform (PI3K-C2alpha) is considered ubiquitous and preferentially activated by insulin rather than the beta-isoform, the physiological significance of PI3K-C2alpha is poorly understood. The present study aimed to determine whether PI3K-C2alpha is associated with the suppression of apoptotic cell death. Different sense- and antisense oligonucleotides (ODNs) were synthesized based on the sequence of C2 domain of PI3K-C2alpha gene. Transfection of CHO-IR cells with two different antisense ODNs clearly reduced the protein content as well as mRNA levels of PI3K-C2alpha whereas neither the nonspecific mock- nor sense ODNs affected. The decrease of PI3K-C2alpha gene expression was paralleled by cellular changes indicating apoptotic cell death such as nuclear condensation, formation of apoptotic bodies, and DNA fragmentation. PI3K-C2alpha mRNA levels were also reduced when cells were incubated in growth factor-deficient medium. Supplementing growth factors (serum or insulin) into medium lead to an increase of PI3K-C2alpha mRNA levels. This finding strongly suggests that PI3K-C2alpha is a crucial survival factor.
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Affiliation(s)
- Shinhae Kang
- Technology Innovation Center, Cheju National University, Jeju, Jeju 690-756, Republic of Korea
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15
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Fricke K, Heitland A, Maronde E. Cooperative activation of lipolysis by protein kinase A and protein kinase C pathways in 3T3-L1 adipocytes. Endocrinology 2004; 145:4940-7. [PMID: 15284193 DOI: 10.1210/en.2004-0803] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the present study, we investigate the coherence of signaling pathways leading to lipolysis in 3T3-L1 adipocytes. We observe two linear signaling pathways: one well known, acting via cAMP and protein kinase A (PKA) activation, and a second one induced by phorbol 12-myristate 13-acetate treatment involving protein kinase C (PKC) and MAPK. We demonstrate that both the PKA regulatory subunits RIalpha and RIIbeta are expressed in 3T3-L1 adipocytes and are responsible for the lipolytic effect mediated via the cAMP/PKA pathway. Inhibition of the PKA pathway by the selective PKA inhibitor Rp-8-CPT-cAMPS does not impair lipolysis induced by PKC activation, and neither PD98059 nor U0126, as known MAPK kinase inhibitors, changes the level of glycerol release caused by PKA activation, indicating no cross-talk between these two pathways when only one is activated. However, when both are activated, they act synergistically on glycerol release. Additional experiments focusing on this synergy show no involvement of MAPK phosphorylation and cAMP formation. Phosphorylation of hormone-sensitive lipase is similar upon stimulation of either pathway, but we demonstrate a difference in the ability of both PKA and the PKC pathway activation to phosphorylate perilipin, which in turn may be an explanation for the different maximal lipolytic effect of both pathways.
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Affiliation(s)
- Katrin Fricke
- IPF PharmaCeuticals GmbH, Feodor-Lynen-Strasse 31, D-30625 Hannover, Germany
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16
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Grant S, Fisher PB, Dent P. The role of signal transduction pathways in drug and radiation resistance. Cancer Treat Res 2003; 112:89-108. [PMID: 12481713 DOI: 10.1007/978-1-4615-1173-1_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Affiliation(s)
- Steven Grant
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia, USA
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17
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Pawelczyk T, Sakowicz M, Podgorska M, Szczepanska-Konkel M. Insulin induces expression of adenosine kinase gene in rat lymphocytes by signaling through the mitogen-activated protein kinase pathway. Exp Cell Res 2003; 286:152-63. [PMID: 12729803 DOI: 10.1016/s0014-4827(03)00090-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The activity of adenosine kinase (AK) was significantly impaired in splenocytes isolated from diabetic rats. Administration of insulin to diabetic animals restored AK activity, protein, and mRNA levels in diabetic splenocytes. Experiments performed on cultured rat lymphocytes demonstrated that insulin did not change the stability of AK mRNA. Insulin induced AK gene expression in a dose- and time-dependent manner. Maximal increases in AK mRNA (3.9-fold) and activity level (3.7-fold) were observed at the fourth and fifth hours of cell incubation with 10 nM insulin, respectively. The insulin effect on AK expression was not influenced by dibutyryl cAMP (dcAMP). On the other hand dcAMP weakly increased (1.7-fold) basal expression of AK. Exposure of rat lymphocytes to wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3K), or rapamycin, an inhibitor of mTOR, did not affect the ability of insulin to stimulate expression of AK. Prior treatment of the cells with 10 microM PD98059, an inhibitor of mitogen-activated protein kinase (MAPK) kinase (MEK) completely blocked insulin-stimulated expression of AK gene. Insulin produced a significant transient increase in the tyrosine phosphorylation of ERK1/2, and PD98059 inhibited this phosphorylation. Furthermore exposure of cells to insulin has resulted in transient phosphorylation of Elk-1 on Ser-383 and sustained elevation of c-Jun and c-Fos protein. The maximal phosphorylation of Elk-1 was observed at 15 min, and was blocked by PD98059. We concluded that insulin stimulates AK gene expression through a series of events occurring sequentially. This includes activation of the MAPK cascade and subsequent phosphorylation of Elk-1 followed by increased expression of c-fos and c-jun genes.
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Affiliation(s)
- Tadeusz Pawelczyk
- Department of Molecular Medicine, Medical University of Gdansk, ul. Debinki 7, paw. 29, 80-211 Gdansk, Poland.
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18
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Yacoub A, McKinstry R, Hinman D, Chung T, Dent P, Hagan MP. Epidermal growth factor and ionizing radiation up-regulate the DNA repair genes XRCC1 and ERCC1 in DU145 and LNCaP prostate carcinoma through MAPK signaling. Radiat Res 2003; 159:439-52. [PMID: 12643788 DOI: 10.1667/0033-7587(2003)159[0439:egfair]2.0.co;2] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This work examined the importance of radiation-induced and ligand-induced EGFR-ERK signaling for the regulation of DNA repair proteins XRCC1 and ERCC1 in prostate carcinoma cells, DU145 (TP53(mut)), displaying EGFR-TGFA-dependent autocrine growth and high MAPK (ERK1/2) activity, and LNCaP (TP53(wt)) cells expressing low constitutive levels of ERK1/2 activity. Using quantitative RT-PCR and Western analyses, we determined that ionizing radiation activated the DNA repair genes XRCC1 and ERCC1 in an ERK1/2-dependent fashion for each cell line. After irradiation, a rapid increase followed by a decrease in ERK1/2 activity preceded the increase in XRCC1/ERCC1 expression in DU145 cells, while only the rapid decrease in ERK1/2 preceded the increase in XRCC1/ERCC1 expression in LNCaP cells. Administration of EGF, however, markedly increased the up-regulation of phospho-ERK, ERCC1 and XRCC1 in both cell lines. Although the EGFR inhibitor tyrphostin (AG-1478) and the MEK inhibitor PD90859 both attenuated EGF-induced levels of the ERCC1 and XRCC1 protein, PD98059 blocked the induction of ERCC1 and XRCC1 by radiation more effectively in both cell lines. Inhibition of ERK at a level that reduced the up-regulation of DNA repair led to the persistence of apurinic/apyrimidinic (AP) sites of DNA damage and increased cell killing. Taken together, these data imply a complex control of DNA repair activation that may be more generally dependent on MAPK (ERK1/2) signaling than was previously noted. These data provide novel insights into the capacity of the EGFR-ERK signaling to modulate DNA repair in cancer cells and into the functional significance of this signaling.
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Affiliation(s)
- Adly Yacoub
- Department of Radiation Oncology, Medical College of Virginia, Virginia Commonwealth University, Richmond, Virginia 23298, USA
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19
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Cho HJ, Jeong HG, Lee JS, Woo ER, Hyun JW, Chung MH, You HJ. Oncogenic H-Ras enhances DNA repair through the Ras/phosphatidylinositol 3-kinase/Rac1 pathway in NIH3T3 cells. Evidence for association with reactive oxygen species. J Biol Chem 2002; 277:19358-66. [PMID: 11884408 DOI: 10.1074/jbc.m200933200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This study investigated the role of oncogenic H-Ras in DNA repair capacity in NIH3T3 cells. Expression of dominant-positive H-Ras (V12-H-Ras) enhanced the host cell reactivation of luciferase activity from UV-irradiated and cisplatin-treated plasmids and also increased the unscheduled DNA synthesis following cisplatin or UV treatment of cells. This observed enhancement of DNA repair capacity was inhibited by transient transfection with dominant-negative H-Ras (N17-H-Ras) or Rac1 (N17-Rac1) plasmids. Moreover, stable transfection of dominant-positive Rac1 (V12-Rac1) further enhanced DNA repair capacity. Because reactive oxygen species (ROS) are known to be a downstream effector of oncogenic Ras, we examined the role of ROS in DNA repair capacity. We found that ROS production by V12-H-Ras expression was mediated by the Ras/phosphatidylinositol 3-kinase (PI3K)/Rac1/NADPH oxidase-dependent pathway and that pretreatment of V12-H-Ras-transformed cells with an antioxidant (N-acetylcysteine) and an NADPH oxidase inhibitor (diphenyleneiodonium) decreased DNA repair capacity. Similarly, treatment with PI3K inhibitors (wortmannin and LY294002) inhibited the ability of oncogenic H-Ras to enhance DNA repair capacity. Furthermore, inhibition of the Ras/PI3K/Rac1/NADPH oxidase pathway resulted in increased sensitivity to cisplatin and UV in V12-H-Ras-expressing NIH3T3 cells. Taken together, these results provide evidence that oncogenic H-Ras activates DNA repair capacity through the Ras/PI3K/Rac1/NADPH oxidase-dependent pathway and that increased ROS production via this signaling pathway is required for enhancement of the DNA repair capacity induced by oncogenic H-Ras.
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Affiliation(s)
- Hyun-Ju Cho
- Department of Pharmacology, School of Medicine, the Research Center for Proteineous Materials, Chosun University, 375 Seosuk-dong, Kwangju 501-759, Korea.
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20
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Héron-Milhavet L, LeRoith D. Insulin-like growth factor I induces MDM2-dependent degradation of p53 via the p38 MAPK pathway in response to DNA damage. J Biol Chem 2002; 277:15600-6. [PMID: 11877395 DOI: 10.1074/jbc.m111142200] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In many tissues, the insulin-like growth factor I (IGF-I) receptor (IGF-IR) is known to functionally oppose apoptosis. Recently, we demonstrated a direct role for the IGF-IR in the rescue of DNA-damaged fibroblasts by activating a DNA repair pathway (Héron-Milhavet, L., Karas, M., Goldsmith, C. M., Baum, B. J., and LeRoith, D. (2001) J. Biol. Chem. 276, 18185-18192). p53 is a nuclear transcription factor that can block progression of the cell cycle, modulate DNA repair, and trigger apoptosis. In this work, we tested the effect of IGF-I on the regulation of the p53 signaling cascade. The DNA-damaging agent 4-nitroquinoline 1-oxide was applied to NIH-3T3 cells overexpressing normal IGF-IRs (NWTb3 cells). We showed that after 4-nitroquinoline 1-oxide-induced DNA damage, IGF-I induced exclusion of the p53 protein from the nucleus and led to its degradation in the cytoplasm, whereas p53 mRNA was unaffected. Degradation of the p53 protein was associated with an increase in MDM2, an upstream modulator of the half-life and activity of the p53 protein. p53 degradation was also associated with down-regulation of p21. We further showed that the effects of IGF-I on mdm2 transcription and on MDM2/p19 ARF association were mediated by the p38 MAPK pathway. In conclusion, we describe a novel role for IGF-I in the regulation of the MDM2/p53/p21 signaling pathway during DNA damage.
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Affiliation(s)
- Lisa Héron-Milhavet
- Section on Cellular and Molecular Physiology, Clinical Endocrinology Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-1758, USA
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21
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Scassa ME, Guberman AS, Varone CL, Cánepa ET. Phosphatidylinositol 3-kinase and Ras/mitogen-activated protein kinase signaling pathways are required for the regulation of 5-aminolevulinate synthase gene expression by insulin. Exp Cell Res 2001; 271:201-13. [PMID: 11716532 DOI: 10.1006/excr.2001.5386] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insulin regulates the expression of several hepatic genes. Although the general definition of insulin signaling has progressed dramatically, the elucidation of the complete signaling pathway from insulin receptor to transcription factors involved in the regulation of a specific gene remains to be established. In fact, recent works suggest that multiple divergent insulin signaling pathways regulate the expression of distinct genes. 5-Aminolevulinate synthase (ALAS) is a mitochondrial matrix enzyme that catalyzes the first and rate-limiting step of heme biosynthesis. It has been reported that insulin caused the rapid inhibition of housekeeping ALAS transcription, but the mechanism involved in this repression has not been explored. The present study investigates the role of phosphatidylinositol 3-kinase (PI3-kinase) and mitogen-activated protein kinase pathways in insulin signaling relevant to ALAS inhibition. To explore this, we combined the transient overexpression of regulatory proteins involved in these pathways and the use of small cell permeant inhibitors in rat hepatocytes and HepG2 cells. Wortmannin and LY294002, PI3-kinase inhibitors, as well as lovastatin and PD152440, Ras farnesylation inhibitors, and MEK inhibitor PD98059 abolished the insulin repression of ALAS transcription. The inhibitor of mTOR/p70(S6K) rapamycin had no effect whatsoever upon hormone action. The overexpression of vectors encoding constitutively active Ras, MEK, or p90(RSK) mimicked the inhibitory action of insulin. Conversely, negative mutants of PKB, Ras, or MEK impaired insulin inhibition of ALAS promoter activity. Furthermore, inhibition of one of the pathways blocks the inhibitory effect produced by the activation of the other. Our findings suggest that factors involved in two signaling pathways that are often considered to be functionally separate during insulin action, the Ras/ERK/p90(RSK) pathway and the PI3K/PKB pathway, are jointly required for insulin-mediated inhibition of ALAS gene expression in rat hepatocytes and human hepatoma cells.
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MESH Headings
- 5-Aminolevulinate Synthetase/genetics
- Androstadienes/pharmacology
- Animals
- Carcinoma, Hepatocellular
- Cells, Cultured
- Chromones/pharmacology
- Enzyme Inhibitors/pharmacology
- Gene Expression Regulation, Enzymologic/physiology
- Genetic Vectors
- Hepatocytes/drug effects
- Hepatocytes/enzymology
- Humans
- Insulin/metabolism
- Insulin/pharmacology
- Liver/drug effects
- Liver/enzymology
- MAP Kinase Signaling System/genetics
- Male
- Morpholines/pharmacology
- Phosphatidylinositol 3-Kinases/metabolism
- Promoter Regions, Genetic/physiology
- Protein Prenylation/drug effects
- Protein Prenylation/physiology
- Protein Serine-Threonine Kinases
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins c-akt
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Rats
- Rats, Inbred Strains
- Ribosomal Protein S6 Kinases/genetics
- Transcription, Genetic/drug effects
- Transcription, Genetic/physiology
- Tubulin/genetics
- Tumor Cells, Cultured
- Wortmannin
- ras Proteins/metabolism
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Affiliation(s)
- M E Scassa
- Laboratorio de Biología Molecular, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II Piso 4 Ciudad Universitaria, Buenos Aires, 1428, Argentina
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22
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Leszczyniecka M, Roberts T, Dent P, Grant S, Fisher PB. Differentiation therapy of human cancer: basic science and clinical applications. Pharmacol Ther 2001; 90:105-56. [PMID: 11578655 DOI: 10.1016/s0163-7258(01)00132-2] [Citation(s) in RCA: 228] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Current cancer therapies are highly toxic and often nonspecific. A potentially less toxic approach to treating this prevalent disease employs agents that modify cancer cell differentiation, termed 'differentiation therapy.' This approach is based on the tacit assumption that many neoplastic cell types exhibit reversible defects in differentiation, which upon appropriate treatment, results in tumor reprogramming and a concomitant loss in proliferative capacity and induction of terminal differentiation or apoptosis (programmed cell death). Laboratory studies that focus on elucidating mechanisms of action are demonstrating the effectiveness of 'differentiation therapy,' which is now beginning to show translational promise in the clinical setting.
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Affiliation(s)
- M Leszczyniecka
- Department of Urology, Herbert Irving Comprehensive Cancer Center, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA
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23
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Reyes-Reyes M, Mora N, Zentella A, Rosales C. Phosphatidylinositol 3-kinase mediates integrin-dependent NF-(κ)B and MAPK activation through separate signaling pathways. J Cell Sci 2001; 114:1579-89. [PMID: 11282033 DOI: 10.1242/jcs.114.8.1579] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Integrin-mediated signals play an important but poorly understood role in regulating many leukocyte functions. In monocytes and monocytic leukemia cells, (β)1 integrin-mediated adhesion results in a strong induction of immediate-early genes that are important in inflammation. To investigate the signaling pathways from integrins in monocytic cells, THP-1 cells were stimulated via (β)1 integrins by binding to fibronectin and by crosslinking the integrins with specific monoclonal antibodies. The involvement of MAPK and PI 3-K on nuclear factor (κ)B (NF-(κ)B) activation was then analyzed. We found that integrins activated both NF-(κ)B and MAPK in a PI 3-K-dependent manner, as wortmannin and LY294002 blocked these responses. However, the specific MEK inhibitor PD98059 did not prevent integrin-mediated NF-(κ)B activation. In contrast, a dominant negative mutant of Rac completely prevented NF-(κ)B activation, but it did not affect MAPK activation. These results indicate that integrin signaling to NF-(κ)B is not mediated by the MAPK pathway, but rather by the small GTPase Rac. In addition, a dominant negative form of Ρ augmented NF-(κ)B activation and blocked MAPK activation, implying that these two pathways are in competition with each other. These data suggest that integrins activate different signaling pathways in monocytic cells. One uses PI 3-K and Rac to activate NF-(κ)B, while the other uses PI 3-K, MEK, and MAPK to activate other nuclear factors, such as Elk-1.
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Affiliation(s)
- M Reyes-Reyes
- Immunology Department at Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
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24
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Asplin IR, Misra UK, Gawdi G, Gonzalez-Gronow M, Pizzo SV. Selective upregulated expression of the alpha2-macroglobulin signaling receptor in highly metastatic 1-LN prostate carcinoma cells. Arch Biochem Biophys 2000; 383:135-41. [PMID: 11097186 DOI: 10.1006/abbi.2000.2052] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cellular binding of receptor-recognized forms of alpha2-macroglobulin (alpha2M*) is mediated by the low-density lipoprotein receptor related protein (LRP) and the alpha2M signaling receptor (alpha2MSR). In nonmalignant cells, ligation of alpha2MSR promotes DNA synthesis and cellular proliferation. Here, we report that insulin treatment of highly metastatic 1-LN human prostate carcinoma selectively increases alpha2MSR expression and binding of alpha2M* to 1-LN cells. alpha2M* induces transient increases in intracellular calcium and inositol 1,4,5-trisphosphate in insulin-treated 1-LN cells, consistent with activation of alpha2MSR. Inhibition of signaling cascades activated by insulin blocks upregulation of alpha2MSR. By contrast, alpha2M* does not bind to nor induce intracellular signaling in PC-3 cells, even though 1-LN cells were subcloned from PC-3 cells. We suggest that alpha2M* behaves like a growth factor in these highly malignant cells. The 1-LN metastatic phenotype may result, in part, from aberrant expression of alpha2MSR, indicating the possible involvement of alpha2M* in tumor progression.
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Affiliation(s)
- I R Asplin
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA
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25
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Shin I, Han JS. Ras GTPase is essential for fas-mediated activation of phospholipase D in A20 cells. Biochem Biophys Res Commun 2000; 271:328-33. [PMID: 10799296 DOI: 10.1006/bbrc.2000.2637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously reported that Fas cross-linking resulted in an increase in phospholipase D activity in A20 murine cells (J.-S. Han et al., Arch. Biochem. Biophys. 367, 233-239, 1999). In an attempt to explore the Fas downstream factor contributing to the activation of phospholipase D, we have investigated the possible involvement of a small GTP biding protein Ras in signaling events that were triggered by Fas cross-linking. Upon adenoviral expression of dominant negative mutant of Ras (N17Ras), an increase in phospholipase D activity by anti-Fas monoclonal antibody was diminished. Also, the Fas downstream signaling events triggered by Fas cross-linking such as the activation of phosphatidylcholine-specific phospholipase C, the increase in diacylglycerol level, and the translocation of protein kinase C to membrane fraction were all reduced by N17Ras expression. When parallel experiments were performed with manumycin-A, a Ras farnensyltransferase inhibitor, almost identical inhibitory effects on Fas downstream signaling were exhibited. These data suggest that Ras GTPase is essential in transmitting phospholipase D activation signal induced by Fas cross-linking and is located at phosphatidylcholine-specific phospholipase C upstream in Fas signaling cascades.
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Affiliation(s)
- I Shin
- Institute of Biomedical Science, Hanyang University, Seoul, 133-791, Korea
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26
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Ali BR, Pal A, Croft SL, Taylor RJ, Field MC. The farnesyltransferase inhibitor manumycin A is a novel trypanocide with a complex mode of action including major effects on mitochondria. Mol Biochem Parasitol 1999; 104:67-80. [PMID: 10589982 DOI: 10.1016/s0166-6851(99)00131-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Eukaryotes modify numerous proteins, including small GTPases of the ras superfamily, with isoprenes as a mechanism for membrane attachment. Inhibition of farnesylation of ras has been successfully exploited to control cell growth, with promise in the clinic for treatment of human tumours. Using an in vitro screen of mammalian farnesyltransferase inhibitors, we have identified manumycin A as potently active against growth of both bloodstream and procyclic forms of Trypanosoma brucei. Other structural classes of farnesyltransferase inhibitors were far less effective. Exposure of T. brucei for brief periods to lethal concentrations of manumycin A resulted in subsequent cell death whilst the concentration required to achieve killing was dependent on serum concentration, suggesting partitioning of manumycin A into hydrophobic cellular sites. Manumycin A did not affect trypanosomal protein and DNA synthesis or cell cycle progression but altered incorporation of prenyl groups into several polypeptides indicating a specific effect on the prenylation without effect on other mevalonate pathway products, most importantly prenyl pyrophosphate levels. Morphological analysis indicated that manumycin A caused significant mitochondrial damage suggesting an additional site of action. Structural analogues of manumycin A containing a quinone were also highly trypanocidal and altered mitochondrial morphology, suggesting interference with electron/proton transport systems. Furthermore, manumycin A also elicited mitochondrial alterations in mammalian cells indicating that the effect is not confined to lower eukaryotes. Manumycin A is well tolerated in vivo but failed to cure experimental trypanosomiasis in mice.
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Affiliation(s)
- B R Ali
- Wellcome Trust Laboratories for Molecular Parasitology, Imperial College of Science, Technology and Medicine, Department of Biochemistry, London, UK
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27
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Misra UK, Gawdi G, Gonzalez-Gronow M, Pizzo SV. Coordinate regulation of the alpha(2)-macroglobulin signaling receptor and the low density lipoprotein receptor-related protein/alpha(2)-macroglobulin receptor by insulin. J Biol Chem 1999; 274:25785-91. [PMID: 10464317 DOI: 10.1074/jbc.274.36.25785] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have studied insulin-dependent regulation of macrophage alpha(2)-macroglobulin signaling receptors (alpha(2)MSR) and low density lipoprotein receptor-related protein/alpha(2)M receptors (LRP/alpha(2)MR) employing cell binding of (125)I-alpha(2)M*, inhibition of binding by receptor-associated protein (RAP) or Ni(2+), LRP/alpha(2)MR mRNA levels, and generation of second messengers. Insulin treatment increased the number of alpha(2)M* high (alpha(2)MSR) and low (LRP/alpha(2)MR) affinity binding sites from 1, 600 and 67,000 to 2,900 and 115,200 sites per cell, respectively. Neither RAP nor Ni(2+) blocked the binding of (125)I-alpha(2)M* to alpha(2)MSR on insulin- or buffer-treated cells, but they both blocked binding to LRP/alpha(2)MR. Insulin significantly increased LRP/alpha(2)MR mRNA levels in a dose- and time-dependent manner. Insulin-augmented (125)I-alpha(2)M* binding to macrophages was severely reduced by wortmannin, LY294002, PD98059, SB203580, or rapamycin. The increase in alpha(2)MSR receptor synthesis was reflected by augmented generation of IP(3) and increased [Ca(2+)](i) levels upon receptor ligation. Incubation of macrophages with wortmannin, LY294002, PD98059, SB203580, rapamycin, or antibodies against insulin receptors before insulin treatment and alpha(2)M* stimulation significantly reduced the insulin-augmented increase in IP(3) and [Ca(2+)](i) levels. Pretreatment of cells with actinomycin D or cycloheximide blocked the synthesis of new alpha(2)MSR. In conclusion, we show here that insulin coordinately regulates macrophage alpha(2)MSR and LRP/alpha(2)MR, utilizing both the PI 3-kinase and Ras signaling pathways to induce new synthesis of these receptors.
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Affiliation(s)
- U K Misra
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA
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28
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Lee-Kwon W, Park D, Baskar PV, Kole S, Bernier M. Antiapoptotic signaling by the insulin receptor in Chinese hamster ovary cells. Biochemistry 1998; 37:15747-57. [PMID: 9843380 DOI: 10.1021/bi9805947] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have sought to determine whether insulin can promote cell survival and protect Chinese hamster ovary (CHO) cells from apoptosis induced by serum starvation. Low concentrations of insulin were antiapoptotic for cells overexpressing wild-type insulin receptors but not in cells transfected with kinase-defective insulin receptor mutants that lacked a functional ATP binding site. However, treatment with orthovanadate (50 microM), a widely used tyrosine phosphatase inhibitor, led a dramatic reduction in internucleosomal DNA fragmentation in both cell lines. Cells transfected with truncated receptor mutants in either the juxtamembrane or C-terminal domain were as responsive as cells overexpressing wild-type receptors in mediating insulin antiapoptotic protection. The mechanisms underlying insulin antiapoptotic protection were investigated using a variety of pharmacological tools known to inhibit distinct signaling pathways. The phosphatidylinositol-3' kinase inhibitors wortmannin and LY294002 had only a modest influence whereas blocking protein farnesylation with manumycin severely disrupted the antiapoptotic capacity of the insulin receptor. Of interest, cells gained antiapoptotic potential following inhibition of extracellular signal-regulated kinase activation with the pharmacological agent PD98059. Insulin induced MKK3/MKK6 phosphorylation and activation of p38 MAP kinase whose activity was inhibited with SB203580. However, the inhibition of p38 MAP kinase had no effect on the protection offered by insulin. We conclude that the antiapoptotic function of the insulin receptor requires intact receptor kinase activity and implicates a farnesylation-dependent pathway. Increase in cellular phosphotyrosine content, however, triggers antiapoptotic signal that may converge downstream of the insulin receptor.
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Affiliation(s)
- W Lee-Kwon
- Diabetes Section, Laboratory of Clinical Investigation, National Institute on Aging, Baltimore, Maryland 21224, USA
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