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Mrowka P, Glodkowska-Mrowka E. PPARγ Agonists in Combination Cancer Therapies. Curr Cancer Drug Targets 2019; 20:197-215. [PMID: 31814555 DOI: 10.2174/1568009619666191209102015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/03/2019] [Accepted: 11/01/2019] [Indexed: 12/15/2022]
Abstract
Peroxisome proliferator-activated receptor-gamma (PPARγ) is a nuclear receptor acting as a transcription factor involved in the regulation of energy metabolism, cell cycle, cell differentiation, and apoptosis. These unique properties constitute a strong therapeutic potential that place PPARγ agonists as one of the most interesting and widely studied anticancer molecules. Although PPARγ agonists exert significant, antiproliferative and tumoricidal activity in vitro, their anticancer efficacy in animal models is ambiguous, and their effectiveness in clinical trials in monotherapy is unsatisfactory. However, due to pleiotropic effects of PPARγ activation in normal and tumor cells, PPARγ ligands interact with many antitumor treatment modalities and synergistically potentiate their effectiveness. The most spectacular example is a combination of PPARγ ligands with tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML). In this setting, PPARγ activation sensitizes leukemic stem cells, resistant to any previous form of treatment, to targeted therapy. Thus, this combination is believed to be the first pharmacological therapy able to cure CML patients. Within the last decade, a significant body of data confirming the benefits of the addition of PPARγ ligands to various antitumor therapies, including chemotherapy, hormonotherapy, targeted therapy, and immunotherapy, has been published. Although the majority of these studies have been carried out in vitro or animal tumor models, a few successful attempts to introduce PPARγ ligands into anticancer therapy in humans have been recently made. In this review, we aim to summarize shines and shadows of targeting PPARγ in antitumor therapies.
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Affiliation(s)
- Piotr Mrowka
- Department of Biophysics and Human Physiology, Medical University of Warsaw, Warsaw, Poland
| | - Eliza Glodkowska-Mrowka
- Department of Laboratory Diagnostics and Clinical Immunology of Developmental Age, Medical University of Warsaw, Warsaw, Poland.,Department of Experimental Hematology, Institute of Hematology and Transfusion Medicine, Warsaw, Poland
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15-Deoxy-∆- 12,14-Prostaglandin J2 (15d-PGJ2), an Endogenous Ligand of PPAR- γ: Function and Mechanism. PPAR Res 2019; 2019:7242030. [PMID: 31467514 PMCID: PMC6699332 DOI: 10.1155/2019/7242030] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 07/14/2019] [Indexed: 02/06/2023] Open
Abstract
15-Deoxy-∆-12,14-prostaglandin J2 (15d-PGJ2), a natural peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist, has been explored in some detail over the last 20 years. By triggering the PPAR-γ signalling pathway, it plays many roles and exerts antitumour, anti-inflammatory, antioxidation, antifibrosis, and antiangiogenesis effects. Although many synthetic PPAR-γ receptor agonists have been developed, as an endogenous product of PPAR-γ receptors, 15d-PGJ2 has beneficial characteristics including rapid expression and the ability to contribute to a natural defence mechanism. In this review, we discuss the latest advances in our knowledge of the biological role of 15d-PGJ2 mediated through PPAR-γ. It is important to understand its structure, synthesis, and functional mechanisms to develop preventive agents and limit the progression of associated diseases.
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Fattahi S, Kosari‐Monfared M, Ghadami E, Golpour M, Khodadadi P, Ghasemiyan M, Akhavan‐Niaki H. Infection‐associated epigenetic alterations in gastric cancer: New insight in cancer therapy. J Cell Physiol 2018; 233:9261-9270. [DOI: 10.1002/jcp.27030] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 06/25/2018] [Indexed: 12/11/2022]
Affiliation(s)
- Sadegh Fattahi
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences Babol Iran
- North Research Center, Pasteur Institute Amol Iran
| | | | - Elham Ghadami
- Department of Genetics Faculty of Medicine, Babol University of Medical Sciences Babol Iran
| | - Monireh Golpour
- Molecular and Cell Biology Research Center, Student Research Committee, Faculty of Medicine, Mazandaran University of Medical Science Sari Iran
| | - Parastoo Khodadadi
- Department of Genetics Faculty of Medicine, Babol University of Medical Sciences Babol Iran
| | - Mohammad Ghasemiyan
- Department of Genetics Faculty of Medicine, Babol University of Medical Sciences Babol Iran
| | - Haleh Akhavan‐Niaki
- Department of Genetics Faculty of Medicine, Babol University of Medical Sciences Babol Iran
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Suh J, Kim DH, Kim EH, Park SA, Park JM, Jang JH, Kim SJ, Na HK, Kim ND, Kim NJ, Suh YG, Surh YJ. 15-Deoxy-Δ 12,14-prostaglandin J 2 activates PI3K-Akt signaling in human breast cancer cells through covalent modification of the tumor suppressor PTEN at cysteine 136. Cancer Lett 2018; 424:30-45. [PMID: 29550515 DOI: 10.1016/j.canlet.2018.03.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 03/09/2018] [Accepted: 03/09/2018] [Indexed: 12/11/2022]
Abstract
15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2), one of the terminal products of cyclooxygenase-2-catalized arachidonic acid metabolism, has been shown to stimulate breast cancer cell proliferation and migration through Akt activation, but the underlying mechanisms remain poorly understood. In the present study, we investigated the effects of 15d-PGJ2 on the activity of PTEN, the inhibitor of the phosphoinositide 3-kinase (PI3K)-Akt axis, in human breast cancer (MCF-7) cells. Since the α,β-unsaturated carbonyl moiety in the cyclopentenone ring of 15d-PGJ2 is electrophilic, we hypothesized that 15d-PGJ2-induced Akt phosphorylation might result from the covalent modification and subsequent inactivation of PTEN that has several critical cysteine residues. When treated to MCF-7 cells, 15d-PGJ2 bound to PTEN, and this was abolished in the presence of the thiol-reducing agent dithiothreitol. A mass spectrometric analysis by using recombinant and endogenous PTEN protein revealed that the cysteine 136 residue (Cys136) of PTEN is covalently modified upon treatment with 15d-PGJ2. Notably, the ability of 15d-PGJ2 to covalently bind to PTEN as well as to induce Akt phosphorylation was abolished in the cells expressing a mutant form of PTEN in which Cys136 was replaced by serine (C136S-PTEN). The present study demonstrates for the first time that electrophilic 15d-PGJ2 directly binds to cysteine 136 of PTEN and provides new insight into PTEN loss in cancer progression associated with chronic inflammation. These observations suggest that 15d-PGJ2 can undergo nucleophilic addition to PTEN, presumably at Cys136, thereby inactivating this tumor suppressor protein with concomitant Akt activation.
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Affiliation(s)
- Jinyoung Suh
- Tumor Microenvironment Global Core Research Center and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, South Korea
| | - Do-Hee Kim
- Tumor Microenvironment Global Core Research Center and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, South Korea
| | - Eun-Hee Kim
- College of Pharmacy, CHA University, Pocheon-si 11160, Gyeonggi-do, South Korea
| | - Sin-Aye Park
- Tumor Microenvironment Global Core Research Center and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, South Korea
| | - Jong-Min Park
- College of Pharmacy, CHA University, Pocheon-si 11160, Gyeonggi-do, South Korea
| | - Jeong-Hoon Jang
- Tumor Microenvironment Global Core Research Center and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, South Korea
| | - Su-Jung Kim
- Tumor Microenvironment Global Core Research Center and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, South Korea
| | - Hye-Kyung Na
- Department of Food Science and Biotechnology, College of Knowedge-Based Services Engineering, Sungshin Women's University, Seoul 02844, South Korea
| | - Nam-Doo Kim
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, South Korea
| | - Nam-Jung Kim
- Department of Pharmacy, Kyung Hee University, Seoul 02453, South Korea
| | - Young Ger Suh
- College of Pharmacy, CHA University, Pocheon-si 11160, Gyeonggi-do, South Korea
| | - Young-Joon Surh
- Tumor Microenvironment Global Core Research Center and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, South Korea.
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Ordonez P, Nandakumar A, Koriyama C, Yamomoto M, Akiba S. Cytotoxic effects of NF-κB inhibitors in combination with anti-herpes agents on Epstein-Barr virus-positive gastric carcinoma in vitro. Mol Med Rep 2016; 14:2359-67. [DOI: 10.3892/mmr.2016.5496] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 06/13/2016] [Indexed: 11/06/2022] Open
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Patel K, Doddapaneni R, Sekar V, Chowdhury N, Singh M. Combination Approach of YSA Peptide Anchored Docetaxel Stealth Liposomes with Oral Antifibrotic Agent for the Treatment of Lung Cancer. Mol Pharm 2016; 13:2049-58. [PMID: 27070720 DOI: 10.1021/acs.molpharmaceut.6b00187] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Therapeutic efficacy of nanocarriers can be amplified by active targeting and overcoming the extracellular matrix associated barriers of tumors. The aim of the present study was to investigate the effect of oral antifibrotic agent (telmisartan) on tumor uptake and anticancer efficacy of EphA2 receptor targeted liposomes. Docetaxel loaded PEGylated liposomes (DPL) functionalized with nickel chelated phospholipid were prepared using a modified hydration method. DPL were incubated with various concentrations of histidine tagged EphA2 receptor specific peptide (YSA) to optimize particle size, zeta potential, and percentage YSA binding. Cellular uptake studies using various endocytosis blockers revealed that a caveolae dependent pathway was the major route for internalization of YSA anchored liposomes of docetaxel (YDPL) in A549 lung cancer cell line. Hydrodynamic diameter and zeta potential of optimized YDPL were 157.3 ± 11.8 nm and -3.64 mV, respectively. Orthotopic lung tumor xenograft (A549) bearing athymic nude mice treated with oral telmisartan (5 mg/kg) for 2 days showed significantly (p < 0.05) higher uptake of YDPL in tumor tissues compared to healthy tissue. Average lung tumor weight of the YDPL + telmisartan treated group was 4.8- and 3.8-fold lower than that of the DPL and YDPL treated groups (p < 0.05). Substantially lower expression (p < 0.05) of EphA2 receptor protein, proliferating cell nuclear antigen (PCNA), MMP-9, and collagen 1A level with increased E-cadherin and TIMP-1 levels in immunohistochemistry and Western blot analysis of lung tumor samples of the combination group confirmed antifibrotic effect with enhanced anticancer activity. Active targeting and ECM remodeling synergistically contributed to anticancer efficacy of YDPL in orthotopic lung cancer.
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Affiliation(s)
- Ketan Patel
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University , Tallahassee, Florida 32307, United States
| | - Ravi Doddapaneni
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University , Tallahassee, Florida 32307, United States
| | - Vasanthakumar Sekar
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University , Tallahassee, Florida 32307, United States
| | - Nusrat Chowdhury
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University , Tallahassee, Florida 32307, United States
| | - Mandip Singh
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University , Tallahassee, Florida 32307, United States
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Inhibition of Prostaglandin Reductase 2, a Putative Oncogene Overexpressed in Human Pancreatic Adenocarcinoma, Induces Oxidative Stress-Mediated Cell Death Involving xCT and CTH Gene Expressions through 15-Keto-PGE2. PLoS One 2016; 11:e0147390. [PMID: 26820738 PMCID: PMC4731085 DOI: 10.1371/journal.pone.0147390] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 01/04/2016] [Indexed: 01/17/2023] Open
Abstract
Prostaglandin reductase 2 (PTGR2) is the enzyme that catalyzes 15-keto-PGE2, an endogenous PPARγ ligand, into 13,14-dihydro-15-keto-PGE2. Previously, we have reported a novel oncogenic role of PTGR2 in gastric cancer, where PTGR2 was discovered to modulate ROS-mediated cell death and tumor transformation. In the present study, we demonstrated the oncogenic potency of PTGR2 in pancreatic cancer. First, we observed that the majority of the human pancreatic ductal adenocarcinoma tissues was stained positive for PTGR2 expression but not in the adjacent normal parts. In vitro analyses showed that silencing of PTGR2 expression enhanced ROS production, suppressed pancreatic cell proliferation, and promoted cell death through increasing 15-keto-PGE2. Mechanistically, silencing of PTGR2 or addition of 15-keto-PGE2 suppressed the expressions of solute carrier family 7 member 11 (xCT) and cystathionine gamma-lyase (CTH), two important providers of intracellular cysteine for the generation of glutathione (GSH), which is widely accepted as the first-line antioxidative defense. The oxidative stress-mediated cell death after silencing of PTGR2 or addition of 15-keto-PGE2 was further abolished after restoring intracellular GSH concentrations and cysteine supply by N-acetyl-L-cysteine and 2-Mercaptomethanol. Our data highlight the therapeutic potential of targeting PTGR2/15-keto-PGE2 for pancreatic cancer.
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Patel K, Chowdhury N, Doddapaneni R, Boakye CHA, Godugu C, Singh M. Piperlongumine for Enhancing Oral Bioavailability and Cytotoxicity of Docetaxel in Triple-Negative Breast Cancer. J Pharm Sci 2015; 104:4417-4426. [PMID: 26372815 PMCID: PMC4706797 DOI: 10.1002/jps.24637] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/15/2015] [Accepted: 08/17/2015] [Indexed: 01/15/2023]
Abstract
Very low oral bioavailability due to extensive pre-systemic metabolism and P-gp efflux has constrained the oral metronomic chemotherapy of docetaxel (DTX). There is tremendous need of compounds facilitating oral delivery of DTX. The research was aimed to investigate the effect of piperlongumine (PPL) on human liver microsomal metabolism, Caco-2 permeability, and cytotoxicity of DTX in triple-negative breast cancer cell lines. Reduction in testosterone and DTX metabolism (twofold increase in half-life) by PPL was comparable to the standard CYP3A4 inhibitor, cyclosporine A. P-gp efflux ratio of DTX across caco-2 monolayer was reduced from 2.37 to 1.52 on co-incubation with PPL. The IC50 value of DTX was reduced three to five times and combination index values in all the cell lines were below 0.6. PPL at non-cytotoxic concentration showed significant enhancement of the antimigration effect of DTX. Expression of tumor markers such as survivin, bcl2, C-myc, and cyclin D1 were downregulated to a great extent with enhanced p53 expression when treated with combination instead of individual drug. Co-treatment with PPL led to 1.68-fold enhancement in DTX bioavailability in SD rats. PPL could be a potential candidate in overcoming the obstacles associated with oral DTX delivery with synergistic anticancer activity.
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Affiliation(s)
- Ketan Patel
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, Florida 32307
| | - Nusrat Chowdhury
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, Florida 32307
| | - Ravi Doddapaneni
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, Florida 32307
| | - Cedar H A Boakye
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, Florida 32307
| | - Chandraiah Godugu
- Department of Regulatory Toxicology, National Institute of Pharmaceutical Education & Research [NIPER], Bala Nagar, Hyderabad, India
| | - Mandip Singh
- College of Pharmacy and Pharmaceutical Sciences, Florida A&M University, Tallahassee, Florida 32307.
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Evaluation of self-emulsified DIM-14 in dogs for oral bioavailability and in Nu/nu mice bearing stem cell lung tumor models for anticancer activity. J Control Release 2015; 213:18-26. [PMID: 26079185 DOI: 10.1016/j.jconrel.2015.06.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 06/11/2015] [Indexed: 12/29/2022]
Abstract
3, 3-Diindolylmethane-14 (DIM-14), a novel lipophilic derivative of DIM, has demonstrated anticancer activity in different types of cancers. However, poor solubility and low oral bioavailability of DIM-14 limit its translational benefits in vivo. This study was carried out to improve the oral bioavailability of DIM-14 via self-emulsifying drug (SED) delivery system in dogs and to evaluate pharmacodynamic characteristics of SED against H1650 stem cell tumor models. DIM-14 was incorporated into an oil, surfactant, and co-surfactant mixture using labrafil and tween-80 to obtain SED. SED were characterized by droplet size, polydispersitiy index (PDI), zeta potential, entrapment efficiency (EE), in vitro permeability and drug release (investigated with Caco-2 monolayers and dissolution apparatus respectively). Pharmacokinetic parameters in dogs were evaluated and analyzed using Winonlin. Anti-tumor activity was carried out in H1650 lung tumor model. Particle size of SED was between 230 and 246 nm and surface charge was negative and ranged from 26.50 to 28.69 mV. Entrapment efficiency of SED was 85%. Pharmacokinetic evaluation in dogs showed increased Cmax (39.18 ± 7.34 vs 21.68 ± 6.3 μg·dL-1), higher AUC0-t (34,481.34 ± 1125.46 vs 14,159.53 ± 702.20 μg·min·dL-1) and improved absorption with 3 times more bioavailability of SED compared to DIM-14 solution. SED showed ~30-59% tumor volume/weight reduction in H1650 tumor model compared to DIM-P solution. Our studies demonstrate the potential application of self-emulsifying drug delivery system (SEDDS), that enhances oral absorption of DIM-14 and increased anti-tumor activity against lung tumor models.
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Ramer R, Walther U, Borchert P, Laufer S, Linnebacher M, Hinz B. Induction but not inhibition of COX-2 confers human lung cancer cell apoptosis by celecoxib. J Lipid Res 2013; 54:3116-29. [PMID: 23943857 DOI: 10.1194/jlr.m042283] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The antitumorigenic mechanism of the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib is still a matter of debate. Among different structurally related COX-2 inhibitors, only celecoxib was found to cause apoptosis and cell death of human lung cancer cells (IC₅₀ values of 19.96 µM [A549], 12.48 µM [H460], and 41.39 µM [H358]) that was paralleled by a time- and concentration-dependent upregulation of COX-2 and peroxisome proliferator-activated receptor γ (PPARγ) at mRNA and protein levels. Apoptotic death of celecoxib-treated cancer cells was suppressed by the PPARγ antagonist GW9662 and by siRNA targeting PPARγ and, surprisingly, also by the selective COX-2 inhibitor NS-398 and siRNA targeting COX-2. NS-398 (1 µM) was shown to suppress celecoxib-induced COX-2 activity. Among the COX-2-dependent prostaglandins (PG) induced upon celecoxib treatment, PGD₂ and 15-deoxy-Δ¹²,¹⁴-PGJ₂ were found to induce a cytosol-to-nucleus translocation of PPARγ as well as a PPARγ-dependent apoptosis. Celecoxib-elicited PPARγ translocation was inhibited by NS-398. Finally, a COX-2- and PPARγ-dependent cytotoxic action of celecoxib was proven for primary human lung tumor cells. Together, our data demonstrate a proapoptotic mechanism of celecoxib involving initial upregulation of COX-2 and PPARγ and a subsequent nuclear translocation of PPARγ by COX-2-dependent PGs.
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Affiliation(s)
- Robert Ramer
- Institute of Toxicology and Pharmacology, University of Rostock, Schillingallee 70, D-18057 Rostock, Germany
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Skelhorne-Gross G, Nicol CJB. The Key to Unlocking the Chemotherapeutic Potential of PPARγ Ligands: Having the Right Combination. PPAR Res 2012; 2012:946943. [PMID: 22966225 PMCID: PMC3395155 DOI: 10.1155/2012/946943] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 03/14/2012] [Indexed: 01/03/2023] Open
Abstract
Despite extensive preclinical evidence that peroxisome proliferator-activated receptor (PPAR)γ activation protects against tumourigenesis, results from a few clinical trials using PPARγ ligands as monotherapy show modest success. In spite of this, several groups reported exciting results with therapeutic regimens that combine PPARγ ligands with other compounds: chemotherapeutic agents, retinoid x receptor (RXR)α agonists, statins, or cell-to-cell signaling molecules in preclinical cancer models and human trials. Here we have compiled an extensive review, consolidating the existing literature, which overwhelmingly supports a beneficial effect of treating with PPARγ ligands in combination with existing chemotherapies versus their monotherapy in cancer. There are many examples in which combination therapy resulted in synergistic/additive effects on apoptosis, differentiation, and the ability to reduce cell growth and tumour burden. There are also studies that indicate that PPARγ ligand pretreatment overcomes resistance and reduces toxicities. Several mechanisms are explored to explain these protective effects. This paper highlights each of these studies that, collectively, make a very strong case for the use of PPARγ ligands in combination with other agents in the treatment and management of several cancers.
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Affiliation(s)
- Graham Skelhorne-Gross
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, Canada K7L 3N6
- Cancer Biology and Genetics Division, Cancer Research Institute, Queen's University, Kingston, ON, Canada K7L 3N6
| | - Christopher J. B. Nicol
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, Canada K7L 3N6
- Cancer Biology and Genetics Division, Cancer Research Institute, Queen's University, Kingston, ON, Canada K7L 3N6
- Department of Biomedical and Molecular Sciences (Pharmacology and Toxicology), Queen's University, Kingston, ON, Canada K7L 3N6
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Emerging PPARγ-Independent Role of PPARγ Ligands in Lung Diseases. PPAR Res 2012; 2012:705352. [PMID: 22778711 PMCID: PMC3385049 DOI: 10.1155/2012/705352] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 03/28/2012] [Accepted: 04/12/2012] [Indexed: 02/06/2023] Open
Abstract
Peroxisome proliferator activated receptor (PPAR)-γ is a nuclear hormone receptor that is activated by multiple agonists including thiazolidinediones, prostaglandins, and synthetic oleanolic acids. Many PPARγ ligands are under investigation as potential therapies for human diseases. These ligands modulate multiple cellular pathways via both PPARγ-dependent and PPARγ-independent mechanisms. Here, we review the role of PPARγ and PPARγ ligands in lung disease, with emphasis on PPARγ-independent effects. PPARγ ligands show great promise in moderating lung inflammation, as antiproliferative agents in combination to enhance standard chemotherapy in lung cancer and as treatments for pulmonary fibrosis, a progressive fatal disease with no effective therapy. Some of these effects occur when PPARγ is pharmaceutically antagonized or genetically PPARγ and are thus independent of classical PPARγ-dependent transcriptional control. Many PPARγ ligands demonstrate direct binding to transcription factors and other proteins, altering their function and contributing to PPARγ-independent inhibition of disease phenotypes. These PPARγ-independent mechanisms are of significant interest because they suggest new therapeutic uses for currently approved drugs and because they can be used as probes to identify novel proteins and pathways involved in the pathogenesis or treatment of disease, which can then be targeted for further investigation and drug development.
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Giaginis C, Politi E, Alexandrou P, Sfiniadakis J, Kouraklis G, Theocharis S. Expression of peroxisome proliferator activated receptor-gamma (PPAR-γ) in human non-small cell lung carcinoma: correlation with clinicopathological parameters, proliferation and apoptosis related molecules and patients' survival. Pathol Oncol Res 2012; 18:875-83. [PMID: 22426809 DOI: 10.1007/s12253-012-9517-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 03/06/2012] [Indexed: 01/02/2023]
Abstract
Peroxisome proliferator-activated receptor-γ (PPAR-γ) has currently been considered as molecular target for the treatment of human metabolic disorders. PPAR-γ has also been implicated in the pathogenesis and progression of several types of cancer, being associated with cell differentiation, growth and apoptosis. The present study aimed to evaluate the clinical significance of PPAR-γ expression in non-small cell lung carcinoma (NSCLC). PPAR-γ protein expression was assessed immunohistochemically in tumoral samples of 67 NSCLC patients and was statistically analyzed in relation to clinicopathological parameters, proliferation and apoptosis related molecules and patients' survival. Positive PPAR-γ expression was prominent in 30 (45 %) out of 67 NSCLC cases. PPAR-γ positivity was more frequently observed in squamous cell lung carcinoma cases compared to lung adenocarcinoma ones (p = 0.048). PPAR-γ positivity was significantly associated with bcl-2 positivity (p = 0.016) and borderline with c-myc positivity (p = 0.052), whereas non associations with grade of differentiation, TNM stage, Ki-67, p53, bax proteins' expression and patients' survival were noted. In the subgroup of squamous cell lung carcinoma cases, PPAR-γ positivity was significantly associated with tumor size (p = 0.038), while in lung adenocarcinoma ones with histopathological grade of differentiation (p = 0.026). The present study supported evidence for possible participation of PPAR-γ in the biological mechanisms underlying the carcinogenic evolution of the lung. Although the survival prediction using PPAR-γ expression as a marker seems uncertain, the observed correlation with apoptosis related proteins reinforces the potential utility of PPAR-γ ligands as cell cycle modulators in future therapeutic approaches in lung cancer.
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Affiliation(s)
- Costantinos Giaginis
- Department of Forensic Medicine and Toxicology, Medical School, University of Athens, 75 Mikras Asias Street, Athens, 11527, Greece.
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Abstract
In this article we review the evolution of cancer research involving PPARgamma, including mechanisms, target genes, and clinical applications. For the last thirteen years, the effects of PPARgamma activity on tumor biology have been studied intensely. Most of this research has focused upon the potential for employing agonists of this nuclear receptor in cancer treatment. As a monotherapy such agonists have shown little success in clinical trials, while they have shown promise as components of combination treatments both in culture and in animal models. Other investigations have explored a possible role for PPARgamma as a tumor suppressor, and as an inducer of differentiation of cancer stem cells. Whereas early studies have yielded variable conclusions regarding the prevalence of PPARgamma mutations in cancer, the protein level of this receptor has been more recently identified as a significant prognostic marker. We predict that indicators of PPARgamma activity may also serve as predictive markers for tailoring treatments.
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Affiliation(s)
- Gregory T Robbins
- Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine
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Jang BG, Jung EJ, Kim WH. Expression of BamHI-A Rightward Transcripts in Epstein-Barr Virus-Associated Gastric Cancers. Cancer Res Treat 2011; 43:250-4. [PMID: 22247711 PMCID: PMC3253868 DOI: 10.4143/crt.2011.43.4.250] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 09/28/2011] [Indexed: 11/22/2022] Open
Abstract
Purpose About 10% of all gastric cancers (GCs) are Epstein-Barr virus (EBV)-associated. However, the oncogene of EBV in gastric carcinogenesis has not yet been established. In the present study, we investigated the virus-derived transcripts in the EBV-infected GC cell line to explore the viral oncogene of EBV-positive GCs. Materials and Methods We used the SNU719 cell line, a naturally derived EBV-infected GC cell line. The individual expressed sequence tags from the cDNA libraries of SNU719 were searched against the mRNA subset extracted from the GenBank data base. Sequence reaction was carried out for the EBV-associated clones. Reverse transcription-polymerase chain reaction was performed after cells were partitioned into nuclear and cytoplasmic fractions. Results Using bioinformatic tools, we selected 13 EBV-associated clones from cDNA libraries of SNU719. By sequencing analysis, we revealed that they were all associated with RPMS1, one of the BamHI-A rightward transcripts (BART) of EBV. Some BART cDNAs such as RPMS1 and A73 are known to be translated into protein in vitro, and have been shown to have some biochemical functions relevant to tumorigenesis. But, presently, the BART transcripts were expressed only in the nucleus and not in the cytoplasm, arguing against their role as messenger RNAs. Some other BART transcripts expressed in GCs (BARF0, CST, vIL, BARF1, BLLF1, and BcLF1) were also extensively detected in the nucleus. Conclusion BART transcripts are the predominant viral transcripts expressed in EBV-associated GCs, and they are located only in the nucleus. Therefore, it seems less likely that BART transcripts produce functional proteins to play a role in carcinogenesis of EBV-associated GCs.
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Affiliation(s)
- Bo-Gun Jang
- Department of Pathology, Seoul National University College of Medicine, Seoul, Korea
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Surh YJ, Na HK, Park JM, Lee HN, Kim W, Yoon IS, Kim DD. 15-Deoxy-Δ¹²,¹⁴-prostaglandin J₂, an electrophilic lipid mediator of anti-inflammatory and pro-resolving signaling. Biochem Pharmacol 2011; 82:1335-51. [PMID: 21843512 DOI: 10.1016/j.bcp.2011.07.100] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 07/28/2011] [Accepted: 07/29/2011] [Indexed: 01/22/2023]
Abstract
15-deoxy-Δ(12,14)-prostagandin J(2) (15d-PGJ2) is produced in the inflamed cells and tissues as a consequence of upregulation of cyclooxygenase-2 (COX-2). 15d-PGJ2 is known to be the endogenous ligand of peroxisome proliferator-activated receptor gamma (PPARγ) with multiple physiological properties. Though one of the terminal products of the COX-2-catalyzed reactions, this cyclopentenone prostaglandin exerts potent anti-inflammatory actions, in part, by antagonizing the activities of pro-inflammatory transcription factors, such as NF-κB, STAT3, and AP-1, while stimulating the anti-inflammatory transcription factor Nrf2. These effects are not necessarily dependent on its activation of PPARγ, but often involves direct interaction with the above signaling molecules and their regulators. The locally produced 15d-PGJ2 is also involved in the resolution of inflammatory responses. Thus, 15d-PGJ2, especially formed during the late phase of inflammation, might inhibit cytokine secretion and other events by antigen-presenting cells like dendritic cells or macrophages. 15d-PGJ2 can also affect the priming and effector functions of T lymphocytes and induce their apoptotic cell death. These represent a negative feedback explaining how once-initiated immunologic and inflammatory responses are switched off and terminated. In this context, 15d-PGJ2 and its synthetic derivatives have therapeutic potential for the treatment of inflammatory disorders.
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Affiliation(s)
- Young-Joon Surh
- WCU Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul 151-742, South Korea.
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Shin HJ, Kim DN, Lee SK. Association between Epstein-Barr virus infection and chemoresistance to docetaxel in gastric carcinoma. Mol Cells 2011; 32:173-9. [PMID: 21626300 PMCID: PMC3887666 DOI: 10.1007/s10059-011-0066-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 05/20/2011] [Accepted: 05/23/2011] [Indexed: 12/13/2022] Open
Abstract
Epstein-Barr virus (EBV) is associated with human cancers such as nasopharyngeal carcinoma, Burkitt's lymphoma, Hodgkin's disease, and gastric carcinoma (GC). EBV is associated with about 10% of all GC cases globally. EBV-associated GC has distinct features from EBV-negative GC. However, it is still unclear if EBV infection has any effect on GC chemoresistance. Cell proliferation assay, cell cycle analysis, and active caspase Western blot revealed that the EBV-positive GC cell line (AGS-EBV) showed chemoresistance to docetaxel compared to the EBV-negative GC cell line (AGS). Docetaxel treatment increased expression of Bax similarly in AGS and AGS-EBV cell lines. However, Bcl-2 induction was markedly higher in AGS-EBV cells, after docetaxel treatment. Although docetaxel increased the expression of p53 to a similar extent in both cell lines, induction of p21 in AGS-EBV cells was lower than in AGS cells. Furthermore, expression of survivin was higher in AGS-EBV cells than in AGS cells following docetaxel treatment as well as at basal state. EBVlytic gene expression was induced by docetaxel treatment in AGS-EBV cells. The results suggest that EBV infection and lytic induction confers chemoresistance to GC, possibly by regulating cellular and EBV latent and lytic gene expression.
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Affiliation(s)
| | | | - Suk Kyeong Lee
- Research Institute of Immunobiology, Department of Medical Lifescience, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
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Peroxisome proliferator-activated receptors in lung cancer. PPAR Res 2011; 2007:90289. [PMID: 18274632 PMCID: PMC2220082 DOI: 10.1155/2007/90289] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Accepted: 07/03/2007] [Indexed: 01/11/2023] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Their discovery in the 1990s provided insights into the cellular mechanisms involved in the control of energy homeostasis; the regulation of cell differentiation, proliferation, and apoptosis; and the modulation of important biological and pathological processes related to inflammation, among others. Since then, PPARs have become an exciting therapeutic target for several diseases. PPARs are expressed by many tumors including lung carcinoma cells, and their function has been linked to the process of carcinogenesis in lung. Consequently, intense research is being conducted in this area with the hope of discovering new PPAR-related therapeutic targets for the treatment of lung cancer. This review summarizes the research being conducted in this area and focuses on the mechanisms by which PPARs are believed to affect lung tumor cell biology.
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Activated PPARgamma Targets Surface and Intracellular Signals That Inhibit the Proliferation of Lung Carcinoma Cells. PPAR Res 2011; 2008:254108. [PMID: 18704200 PMCID: PMC2515882 DOI: 10.1155/2008/254108] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Accepted: 06/24/2008] [Indexed: 11/17/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors belonging to the nuclear hormone receptor superfamily. Their discovery in the 1990s provided insights into the cellular mechanisms involved in the control of energy homeostasis, the regulation of cell differentiation, proliferation, and apoptosis, and the modulation of important biological and pathological processes related to inflammation and cancer biology, among others. Since then, PPARs have become an exciting target for the development of therapies directed at many disorders including cancer. PPARs are expressed in many tumors including lung cancer, and their function has been linked to the process of carcinogenesis. Consequently, intense research is being conducted in this area with the hope of discovering new PPAR-related therapeutic targets for the treatment of lung cancer. This review summarizes the research being conducted in this area, and focuses on the mechanisms by which a member of this family (PPARγ) is believed to affect lung tumor cell biology.
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20
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PPARgamma and Apoptosis in Cancer. PPAR Res 2011; 2008:704165. [PMID: 18615184 PMCID: PMC2442903 DOI: 10.1155/2008/704165] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 04/21/2008] [Accepted: 06/11/2008] [Indexed: 12/22/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand binding transcription factors which function in many physiological roles including lipid metabolism, cell growth, differentiation, and apoptosis. PPARs and their ligands have been shown to play a role in cancer. In particular, PPARγ ligands including endogenous prostaglandins and the synthetic thiazolidinediones (TZDs) can induce apoptosis of cancer cells with antitumor activity. Thus, PPARγ ligands have a potential in both chemoprevention and therapy of several types of cancer either as single agents or in combination with other antitumor agents. Accordingly, the involvement of PPARγ and its ligands in regulation of apoptosis of cancer cells have been extensively studied. Depending on cell types or ligands, induction of apoptosis in cancer cells by PPARγ ligands can be either PPARγ-dependent or -independent. Through increasing our understanding of the mechanisms of PPARγ ligand-induced apoptosis, we can develop better strategies which may include combining other antitumor agents for PPARγ-targeted cancer chemoprevention and therapy. This review will highlight recent research advances on PPARγ and apoptosis in cancer.
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Yokoyama Y, Xin B, Shigeto T, Mizunuma H. Combination of ciglitazone, a peroxisome proliferator-activated receptor gamma ligand, and cisplatin enhances the inhibition of growth of human ovarian cancers. J Cancer Res Clin Oncol 2011; 137:1219-28. [DOI: 10.1007/s00432-011-0993-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 06/06/2011] [Indexed: 11/30/2022]
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Contribution of Epstein-Barr virus infection to chemoresistance of gastric carcinoma cells to 5-fluorouracil. Arch Pharm Res 2011; 34:635-43. [PMID: 21544729 DOI: 10.1007/s12272-011-0414-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 01/06/2011] [Accepted: 01/06/2011] [Indexed: 12/26/2022]
Abstract
Although Epstein-Barr virus (EBV) is associated with 6-16% of the gastric carcinoma (GC) cases, the effect of EBV infection on the tumorigenesis process and the responsiveness to chemotherapy remain unclear. We compared chemosensitivity of the EBV-positive GC (AGSEBV) and EBV-negative GC (AGS) cells to 5-fluorouracil (5-FU). Although 5-FU inhibited the growth of both cell lines in a dose- and time-dependent manner, the sensitivity of EBV-positive GC cells to 5-FU was lower than that of EBV-negative GC cells. The cleavage of PARP and caspase-3 was also lower in AGS-EBV cells than in AGS cells following 5-FU treatment. Both the level of Bcl-2 expression and the ratio of Bcl-2/Bax were higher in AGS-EBV than in AGS cells not only at basal state but also following 5-FU treatment. Moreover, p53 and p21 expression was enhanced further by 5-FU in AGS than in AGS-EBV cells. Immunofluorescence assay and Western blot showed that 5-FU induced the expression of EBV-lytic genes including BZLF1, BRLF1, BMRF1 and BHRF1. Our results suggest that latent and lytic EBV infection contributes to the chemoresistance to 5-FU in gastric carcinoma by modulating apoptosis related cellular genes.
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Bortezomib induction of C/EBPβ mediates Epstein-Barr virus lytic activation in Burkitt lymphoma. Blood 2011; 117:6297-303. [PMID: 21447826 DOI: 10.1182/blood-2011-01-332379] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Epstein-Barr virus (EBV) is associated with a variety of lymphoid malignancies. Bortezomib activates EBV lytic gene expression. Bortezomib, a proteasome inhibitor, leads to increased levels of CCAAT/enhancer-binding proteinβ (C/EBPβ) in a variety of tumor cell lines. C/EBPβ activates the promoter of the EBV lytic switch gene ZTA. Bortezomib treatment leads to increased binding of C/EBP to previously recognized binding sites in the ZTA promoter. Knockdown of C/EBPβ inhibits bortezomib activation of EBV lytic gene expression. Bortezomib also induces the unfolded protein response (UPR), as evidenced by increases in ATF4, CHOP10, and XBP1s and cleavage of ATF6. Thapsigargin, an inducer of the UPR that does not interfere with proteasome function, also induces EBV lytic gene expression. The effects of thapsigargin on EBV lytic gene expression are also inhibited by C/EBPβ knock-down. Therefore, C/EBPβ mediates the activation of EBV lytic gene expression associated with bortezomib and another UPR inducer.
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Diminished lipocalin-type prostaglandin D2 synthase expression in human lung tumors. Lung Cancer 2010; 70:103-9. [DOI: 10.1016/j.lungcan.2010.01.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 01/06/2010] [Accepted: 01/17/2010] [Indexed: 01/08/2023]
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Shin JY, Kim JO, Lee SK, Chae HS, Kang JH. LY294002 may overcome 5-FU resistance via down-regulation of activated p-AKT in Epstein-Barr virus-positive gastric cancer cells. BMC Cancer 2010; 10:425. [PMID: 20704765 PMCID: PMC3087326 DOI: 10.1186/1471-2407-10-425] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 08/13/2010] [Indexed: 12/16/2022] Open
Abstract
Background As EBV-associated gastric cancer has unique features that are different from EBV (-) gastric cancer, EBV is considered to have a key role in gastric carcinogenesis. It has been reported that viral latent membrane protein 2A (LMP2A) in EBV-transformed tumor cells activates the phosphatidylinositol 3-kinase (PI3K)/AKT pathway, which provides a survival signal and chemo-resistance to cytotoxic anti-cancer drugs. This study was to evaluate anti-proliferative effect and cell cycle change when 5-FU and LY294002 (LY), a selective inhibitor of PI3K, were treated separately or combined with different schedules in EBV positive gastric cancer cell line, SNU-719. Methods After single treatment and sequential combination of 5-FU and LY, cytotoxic activity was measured by MTS assay. When 5-FU and LY were treated in single and sequential combinations, the expression of p-AKT, p-NFkB, p-p53 and bcl-2 was observed on different concentrations by Western blot analysis. We also investigated the effect on apoptosis and cell cycle distribution using flow cytometry. The LMP2A siRNA inhibition was done to confirm the reversal of decreased 5-FU activity and p-AKT. Results When 5-FU was sequentially combined with LY, the combination index (CI) value indicated synergistic anti-proliferative effect. The expression of p-AKT and p-NFκB was upregulated by 5-FU alone but sequential treatment of 5-FU and LY decreased the expression of both p-AKT and p-NFκB. When 5-FU was combined with LY, G0/G1 and sub G1 cell population (%) increased. When 5-FU was added to the cells transfected with LMP2A siRNA, its anti-proliferative effect increased and the expression of p-AKT decreased. In sequential combination of 5-FU and LY, the expression of p-p53 was increased and bcl-2 expression was diminished compared to 5-FU alone. Conclusion These data suggest that sequential combination of 5-FU and LY induce synergistic cytotoxicity and overcome intrinsic and acquired resistance of 5-FU via downregulation of activated p-AKT and mitochondria-dependent apoptosis in EBV gastric cancer cell line, SNU-719.
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Affiliation(s)
- Jung-Young Shin
- Department of Biomedical Sciences, The Catholic University of Korea, Seoul, Korea.
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Albumin-binding and tumor vasculature determine the antitumor effect of 15-deoxy-Delta-(12,14)-prostaglandin-J(2) in vivo. Neoplasia 2010; 11:1348-58. [PMID: 20019843 DOI: 10.1593/neo.91188] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 09/11/2009] [Accepted: 09/14/2009] [Indexed: 12/14/2022] Open
Abstract
15-Deoxy-Delta(12,14)-prostaglandin-J(2) (15d-PGJ(2)), a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, induces cell death in tumor cells in vitro; however, no study showed its in vivo effect on tumors. Here, we report that 15d-PGJ(2) shows antitumor effects in vivo in mice. However, its effects correlate with tumor uptake of albumin, to which it reversibly binds. 15d-PGJ(2) induces cell death in B16F10 melanoma and C26 colon carcinoma cells in vitro. These effects were not elicited through PPARgamma-dependent pathways because an irreversible PPARgamma antagonist GW9662 did not inhibit these effects. Caspase- and nuclear factor kappaB- (NF-kappaB) dependent pathways were found to be involved as determined with caspase-3/7 fluorescent assay and NF-kappaB containing plasmid transfection assay, respectively. Noticeably, 15d-PGJ(2) had significantly stronger effects in C26 cells compared with B16 cells in all assays. However, in vivo, there was no effect on C26 tumors, yet it significantly inhibited the B16 tumor growth in mice by 75%. We found that 15d-PGJ(2) rapidly bound to albumin and in vivo albumin greatly distributed to B16 tumors compared with C26 tumors, shown with gamma-camera imaging and immunohistochemical staining. Albumin accumulation can be attributed to the large blood vessel diameter in B16 tumors and an enhanced permeability and retention effect. These findings suggest that 15d-PGJ(2) can be an effective therapeutic agent for cancer, although its effects seem to be limited to the tumors allowing albumin penetration.
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Han SW, Roman J. Anticancer actions of PPARγ ligands: Current state and future perspectives in human lung cancer. World J Biol Chem 2010; 1:31-40. [PMID: 21537367 PMCID: PMC3083946 DOI: 10.4331/wjbc.v1.i3.31] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 03/23/2010] [Accepted: 03/24/2010] [Indexed: 02/05/2023] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand-dependent nuclear transcription factors and members of the nuclear receptor superfamily. Of the three PPARs identified to date (PPARγ, PPARβ/δ, and PPARα), PPARγ has been studied the most, in part because of the availability of PPARγ agonists (also known as PPARγ ligands) and its significant effects on the management of several human diseases including type 2 diabetes, metabolic syndrome, cardiovascular disease and cancers. PPARγ is expressed in many tumors including lung cancer, and its function has been linked to the process of lung cancer development, progression and metastasis. Studies performed in gynogenic and xenograft models of lung cancer showed decreased tumor growth and metastasis in animals treated with PPARγ ligands. Furthermore, data are emerging from retrospective clinical studies that suggest a protective role for PPARγ ligands on the incidence of lung cancer. This review summarizes the research being conducted in this area and focuses on the mechanisms and potential therapeutic effects of PPARγ ligands as a novel anti-lung cancer treatment strategy.
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Affiliation(s)
- Shou Wei Han
- Shou Wei Han, Jesse Roman, Division of Pulmonary, Critical Care and Sleep Disorders Medicine, Department of Medicine, University of Louisville School of Medicine, Louisville, KY 40202, United States
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Ichite N, Chougule MB, Jackson T, Fulzele SV, Safe S, Singh M. Enhancement of docetaxel anticancer activity by a novel diindolylmethane compound in human non-small cell lung cancer. Clin Cancer Res 2009; 15:543-52. [PMID: 19147759 DOI: 10.1158/1078-0432.ccr-08-1558] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE This study was conducted to examine the cytotoxic effects of a peroxisome proliferator-activated receptor gamma (PPARgamma) agonist, 1,1-bis (3'-indolyl)-1-(p-biphenyl) methane (DIM-C-pPhC(6)H(5)), alone and in combination with docetaxel in vitro in A549 lung cancer cells and in vivo in nude mice bearing A549 orthotopic lung tumors. EXPERIMENTAL DESIGN Isobolographic method was used to calculate combination index values from cell viability data. Apoptosis was evaluated in A549 cells by terminal deoxynucleotidyl transferase-mediated nick end labeling assay and measurement of cleaved poly(ADP-ribose) polymerase level. Expression of proteins was studied by Western blotting. A549 cells were implanted to induce orthotopic lung tumors in nude mice and the efficacy of docetaxel, DIM-C-pPhC(6)H(5), or combination was determined. Apoptosis and cleaved caspase-3 expression in the harvested tissues were studied by terminal deoxynucleotidyl transferase-mediated nick end labeling and immunohistochemistry, respectively. RESULTS The combination index values (0.36-0.9) suggested synergistic to additive effects of docetaxel + DIM-C-pPhC(6)H(5) and resulted in the highest increase in percentage of apoptotic cells and expression of cleaved poly(ADP-ribose) polymerase, Bax, and N-cadherin compared with treatment with either agent. The combination also enhanced procaspase-3 and -9 cleavage. In vivo, docetaxel + DIM-C-pPhC(6)H(5) reduced lung weights by 57% compared with 39% by docetaxel or 22% by DIM-C-pPhC(6)H(5) alone, induced apoptosis in 43% of the tumor cells compared with 29% and 22% in tumors treated with docetaxel and DIM-C-pPhC(6)H(5), respectively, and increased procaspase-3 cleavage compared with either agent alone. CONCLUSIONS These findings suggest potential benefit for use of docetaxel and DIM-C-pPhC(6)H(5) combination in lung cancer treatment.
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Affiliation(s)
- Nkechi Ichite
- College of Pharmacy and Pharmaceutical Sciences. Florida A&M University, Tallahassee, Florida 32307, USA
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Sun X, Ritzenthaler JD, Zheng Y, Roman J, Han S. Rosiglitazone inhibits alpha4 nicotinic acetylcholine receptor expression in human lung carcinoma cells through peroxisome proliferator-activated receptor gamma-independent signals. Mol Cancer Ther 2009; 8:110-8. [PMID: 19139119 DOI: 10.1158/1535-7163.mct-08-0719] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We and others have shown previously that nicotine, a major component of tobacco, stimulates non-small cell lung carcinoma (NSCLC) proliferation through nicotinic acetylcholine receptor (nAChR)-mediated signals. Activation of peroxisome proliferator-activated receptor gamma (PPARgamma) has been shown to inhibit NSCLC cell growth, but the exact mechanisms responsible for this effect remain incompletely defined. Herein, we show that nicotine induces NSCLC cell proliferation in part through alpha4 nAChR, prompting us to explore the effects of rosiglitazone, a synthetic PPARgamma ligand, on the expression of this receptor. Rosiglitazone inhibited the expression of alpha4 nAChR, but this effect was through a PPARgamma-independent pathway, because GW9662, an antagonist of PPARgamma, and the transfection of cells with PPARgamma small interfering RNA failed to abolish the response. The inhibitory effect of rosiglitazone on alpha4 nAChR expression was accompanied by phosphorylation of p38 mitogen-activated protein kinase and extracellular signal-regulated kinase 1/2 and down-regulation of Akt phosphorylation. These signals mediated the inhibitory effects of rosiglitazone on alpha4 nAChR expression because chemical inhibitors prevented the effect. Rosiglitazone was also found to stimulate p53, a tumor suppressor known to mediate some of the effects of nicotine. Interestingly, p53 up-regulation was needed for rosiglitazone-induced inhibition of alpha4 nAChR. Thus, rosiglitazone inhibits alpha4 nAChR expression in NSCLC cells through activation of extracellular signal-regulated kinase and p38 mitogen-activated protein kinase, which triggers induction of p53. Finally, like others, we found that nicotine stimulated the expression of alpha4 nAChR. This process was also inhibited by rosiglitazone through similar pathways.
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Affiliation(s)
- Xiaojuan Sun
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, Emory University School of Medicine, Whitehead Bioresearch Building, 615 Michael Street, Suite 205-M, Atlanta, GA 30322, USA
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PPARgamma and Agonists against Cancer: Rational Design of Complementation Treatments. PPAR Res 2008; 2008:945275. [PMID: 19043603 PMCID: PMC2586323 DOI: 10.1155/2008/945275] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Accepted: 08/21/2008] [Indexed: 01/22/2023] Open
Abstract
PPARγ is a member of the ligand-activated nuclear receptor superfamily: its ligands act as insulin sensitizers and some are approved for the treatment of metabolic disorders in humans. PPARγ has pleiotropic effects on survival and proliferation of multiple cell types, including cancer cells, and is now subject of intensive preclinical cancer research. Studies of the recent decade highlighted PPARγ role as a potential modulator of angiogenesis in vitro and in vivo. These observations provide an additional facet to the PPARγ image as potential anticancer drug. Currently PPARγ is regarded as an important target for the therapies against angiogenesis-dependent pathological states including cancer and vascular complications of diabetes. Some of the studies, however, identify pro-angiogenic and tumor-promoting effects of PPARγ and its ligands pointing out the need for further studies. Below, we summarize current knowledge of PPARγ regulatory mechanisms and molecular targets, and discuss ways to maximize the beneficial activity of the PPARγ agonists.
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Nagata D, Yoshihiro H, Nakanishi M, Naruyama H, Okada S, Ando R, Tozawa K, Kohri K. Peroxisome proliferator-activated receptor-gamma and growth inhibition by its ligands in prostate cancer. ACTA ACUST UNITED AC 2008; 32:259-66. [PMID: 18789607 DOI: 10.1016/j.cdp.2008.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2008] [Indexed: 01/02/2023]
Abstract
BACKGROUND Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is expressed in certain human cancers. Ligand-induced PPAR-gamma activation can result in growth inhibition and differentiation in these cancer cells; however, the precise mechanism for the anti-proliferative effect of PPAR-gamma ligands is not clear. METHODS In this study, we examined the expression of PPAR-gamma in human prostate cancer and the effect of two PPAR-gamma ligands, 15 deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2) and troglitazone, on prostate cancer cell growth. RESULTS PPAR-gamma is frequently over-expressed in androgen independent prostate cancer cell lines and human prostate cancer tissues (22 of 47; 47%). Both 15d-PGJ2 and troglitazone inhibited proliferation and DNA synthesis of prostate cancer cell lines in a dose-dependent manner, and slightly increased the proportion of cells with S-phase DNA content. Prostate specific antigen (PSA) promoter reporter assays showed that troglitazone and 15d-PGJ2 down-regulated androgen stimulated reporter gene activity in prostate cancer cell lines LNCaP. Interestingly, LNCaP with troglitazone dramatically suppressed PSA protein expression without suppressing AR expression. CONCLUSIONS Taken together, these results suggest that PPAR-gamma ligands may be a useful therapeutic agent for the treatment of prostate cancer.
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Affiliation(s)
- Daisuke Nagata
- Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Japan
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Chemotherapeutic drugs induce PPAR-gamma expression and show sequence-specific synergy with PPAR-gamma ligands in inhibition of non-small cell lung cancer. Neoplasia 2008; 10:597-603. [PMID: 18516296 DOI: 10.1593/neo.08134] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 03/14/2008] [Accepted: 03/17/2008] [Indexed: 12/19/2022] Open
Abstract
Preclinical studies have shown that peroxisome proliferator-activated receptor gamma (PPAR-gamma) ligands can exert antitumor effects against non-small cell lung cancer (NSCLC) and a variety of other cancers. In this study, we investigate the potential use of a PPAR-gamma ligand, troglitazone (Tro), in combination with either of two chemotherapeutic agents, cisplatin (Cis) or paclitaxel (Pac), for the treatment of NSCLC. In vitro, treatment of NSCLC cell lines with Tro potentiated Cis- or Pac-induced growth inhibition. The potentiation of growth inhibition was observed only when Cis or Pac treatment was followed by Tro and not vice versa, demonstrating a sequence-specific effect. Median effect analysis revealed a synergistic interaction between Tro and Cis in the inhibition of NSCLC cell growth and confirmed the sequence-specific effect. We also found that Cis or Pac up-regulated the expression of PPAR-gamma protein, accounting for the observed sequence-specific synergy. Similarly, experiments performed using a NSCLC xenograft model demonstrated enhanced effectiveness of combined treatment with Cis and PPAR-gamma ligands, Tro or pioglitazone. Tumors from Cis-treated mice also demonstrated enhanced PPAR-gamma expression. Together, our data demonstrate a novel sequence-specific synergy between PPAR-gamma ligands and chemotherapeutic agents for lung cancer treatment.
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Ho TC, Chen SL, Yang YC, Chen CY, Feng FP, Hsieh JW, Cheng HC, Tsao YP. 15-deoxy-Delta(12,14)-prostaglandin J2 induces vascular endothelial cell apoptosis through the sequential activation of MAPKS and p53. J Biol Chem 2008; 283:30273-88. [PMID: 18718914 DOI: 10.1074/jbc.m804196200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
15-Deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) is a potent anti-angiogenic factor and induces endothelial cell apoptosis, although the mechanism remains unclear. In this study, 15d-PGJ(2) was found to increase p53 levels of the human umbilical vein endothelial cells by stabilizing p53. Both 15d-PGJ(2)-induced apoptosis and the induction of p21(Waf1) and Bax can be abolished by p53 small interfering RNA but not by peroxisome proliferator-activated receptor gamma inhibitors. Moreover, 15d-PGJ(2) activated JNK and p38 MAPK while inducing p53 phosphorylation at sites responsible for p53 activity. JNK inhibitor (SP600125) or p38 MAPK inhibitor (SB203580) pretreatment attenuated 15d-PGJ(2)-mediated apoptosis and suppressed the p21(Waf1) and Bax expressions without affecting p53 protein accumulation. Pretreatment with SP600125 partially prevented the phosphorylation of p53 at serines 33 and 392 induced by 15d-PGJ(2). 15d-PGJ(2) was also found to induce reactive oxygen species generation and partially blocked nuclear factor-kappaB activity. Pretreatment with antioxidant N-acetylcysteine prevented the p53 accumulation, the phosphorylations of JNK and p38 MAPK, the inhibition of NF-kappaB activity, as well as the apoptosis induced by 15d-PGJ(2). Using a mouse model of corneal neovascularization, it was demonstrated in vivo that 15d-PGJ(2) induced reactive oxygen species generation, activated JNK and p38 MAPK, induced p53 accumulation/phosphorylation, and induced vascular endothelial cell apoptosis, which could be abolished by N-acetylcysteine, SP600125, SB203580, or a virus-derived amphipathic peptides-based p53 small interfering RNA. This is the first study that 15d-PGJ(2) induces vascular endothelial cell apoptosis through the signaling of JNK and p38 MAPK-mediated p53 activation both in vitro and in vivo, further establishing the potential of 15d-PGJ(2) as an anti-angiogenesis agent.
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Affiliation(s)
- Tsung-Chuan Ho
- Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan
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Jackson T, Chougule MB, Ichite N, Patlolla RR, Singh M. Antitumor activity of noscapine in human non-small cell lung cancer xenograft model. Cancer Chemother Pharmacol 2008; 63:117-26. [PMID: 18338172 DOI: 10.1007/s00280-008-0720-z] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 02/22/2008] [Indexed: 12/12/2022]
Abstract
PURPOSE An antitussive plant alkaloid, Noscapine HCl (Nos) displays anticancer activity and has a safe pharmacological profile in humans. The current study was aimed to investigate the in vitro and in vivo anti tumor activity of Nos to determine possible mechanisms of anti tumor activity for treatment of non-small cell lung cancer (NSCLC). METHODS In vitro cytotoxicity of Nos was studied in H460 cells treated with different doses of Nos (10-160 microM) for 72 h and cell viability was determined using crystal violet assay. Apoptosis in H460 cells was evaluated by TUNEL assay after treatment of cells for 72 h with 30 and 40 microM doses of Nos. For in vivo studies, female athymic Nu/nu mice were xenografted with H460 tumors and on day 4 onwards Nos was administered orally at dose of 300, 450 and 550 mg/kg/day for 24 days. As a control, xenografted tumors were separately treated with Docetaxel (10 mg/kg i.v. bolus on day 5, 11, 17, 23). The tumor volumes were measured every five days. Expression of PARP, Bcl(2, )Bax, and caspase-3 families of proteins was measured by Western Blotting (WB), while TUNEL and Immunohistochemical methods were utilized to determine DNA fragmentation and cleaved caspase-3 levels respectively. RESULTS Nos inhibited growth of H460 cells with the IC50 values of 34.7 +/- 2.5 microM. Nos at 30 and 40 microM doses caused apoptosis as evidenced by nuclear condensation in treated H460 cells. Nos caused 49, 65 and 86% reduction in the xenografted tumor volumes at a dose of 300 (P < 0.05), 450 (P < 0.01), 550 mg/kg/day (P < 0.01), respectively, when compared to controls. Nos-dependent suppression of xenografted tumor growth involved up regulation of PARP, Bax, caspase-3 and repression of Bcl(2) expression. An increase in Bax/Bcl(2) ratio suggests involvement of a mitochondrial mediated apoptotic processes. Our studies revealed a non significant (P > 0.05) increase in Bax/Bcl(2) ratio with Nos at a dose of 300 mg/kg/day, while a significant (P < 0.001) increase in Bax/Bcl(2) ratio was observed with Nos doses of 450 and 550 mg/kg/day. Further, Nos caused elevated apoptosis in tumor xenografts as evidenced by enhanced expression of caspase-3 and positive TUNEL staining in regressed tumor tissues, thus suggesting induction of apoptosis by mitochondrial pathway. CONCLUSION Our studies suggest that potent antitumor activity of Nos against NSCLC cells. Oral administration of Nos showed significant reduction in tumor volume in human non-small cell lung tumor xenograft in nude mice in a dose dependant manner. Thus, Nos is a promising novel chemotherapeutic agent for the treatment of human lung cancer.
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Affiliation(s)
- Tanise Jackson
- College of Pharmacy, Florida A&M University, Tallahassee, FL, 32307, USA
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Shimizu M, Moriwaki H. Synergistic Effects of PPARgamma Ligands and Retinoids in Cancer Treatment. PPAR Res 2008; 2008:181047. [PMID: 18528526 PMCID: PMC2408709 DOI: 10.1155/2008/181047] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Revised: 04/21/2008] [Accepted: 05/01/2008] [Indexed: 01/04/2023] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily. The activation of PPARs by their specific ligands is regarded as one of the promising strategies to inhibit cancer cell growth. However, recent clinical trials targeting several common cancers showed no beneficial effect when PPAR ligands are used as a monotherapy. Retinoid X receptors (RXRs), which play a critical role in normal cell proliferation as a master regulator for nuclear receptors, preferentially form heterodimers with PPARs. A malfunction of RXRalpha due to phosphorylation by the Ras/MAPK signaling pathway is associated with the development of certain types of human malignancies. The activation of PPARgamma/RXR heterodimer by their respective ligands synergistically inhibits cell growth, while inducing apoptosis in human colon cancer cells when the phosphorylation of RXRalpha was inhibited. We herein review the synergistic antitumor effects produced by the combination of the PPAR, especially PPARgamma, ligands plus other agents, especially retinoids, in a variety of human cancers. We also focus on the phosphorylation of RXRalpha because the inhibition of RXRalpha phosphorylation and the restoration of its physiological function may activate PPAR/RXR heterodimer and, therefore, be a potentially effective and critical strategy for the inhibition of cancer cell growth.
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Affiliation(s)
- Masahito Shimizu
- Department of Medicine, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan
| | - Hisataka Moriwaki
- Department of Medicine, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan
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