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Targeting Nuclear Receptors in Lung Cancer—Novel Therapeutic Prospects. Pharmaceuticals (Basel) 2022; 15:ph15050624. [PMID: 35631448 PMCID: PMC9145966 DOI: 10.3390/ph15050624] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/10/2022] [Accepted: 05/13/2022] [Indexed: 01/27/2023] Open
Abstract
Lung cancer, the second most commonly diagnosed cancer, is the major cause of fatalities worldwide for both men and women, with an estimated 2.2 million new incidences and 1.8 million deaths, according to GLOBOCAN 2020. Although various risk factors for lung cancer pathogenesis have been reported, controlling smoking alone has a significant value as a preventive measure. In spite of decades of extensive research, mechanistic cues and targets need to be profoundly explored to develop potential diagnostics, treatments, and reliable therapies for this disease. Nuclear receptors (NRs) function as transcription factors that control diverse biological processes such as cell growth, differentiation, development, and metabolism. The aberrant expression of NRs has been involved in a variety of disorders, including cancer. Deregulation of distinct NRs in lung cancer has been associated with numerous events, including mutations, epigenetic modifications, and different signaling cascades. Substantial efforts have been made to develop several small molecules as agonists or antagonists directed to target specific NRs for inhibiting tumor cell growth, migration, and invasion and inducing apoptosis in lung cancer, which makes NRs promising candidates for reliable lung cancer therapeutics. The current work focuses on the importance of various NRs in the development and progression of lung cancer and highlights the different small molecules (e.g., agonist or antagonist) that influence NR expression, with the goal of establishing them as viable therapeutics to combat lung cancer.
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Tsujiya Y, Hasegawa A, Yamamori M, Okamura N. Troglitazone-Induced Autophagic Cytotoxicity in Lung Adenocarcinoma Cell Lines. Biol Pharm Bull 2022; 45:276-283. [PMID: 35228393 DOI: 10.1248/bpb.b21-00785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Lung cancer is the leading cause of cancer-related deaths worldwide. Troglitazone (TGZ), a peroxisome proliferator-activated receptor gamma (PPARγ) ligand, is a potential antitumor agent. However, the action mechanism of TGZ in lung adenocarcinoma cells has not been completely elucidated. To assess this mechanism and the anticancer effects of TGZ in human lung adenocarcinoma cell lines (A549 and H1975), we investigated the involvement of PPARγ, apoptosis, the mitogen-activated protein kinase (MAPK) pathway, protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway, and autophagy. Cell viability was measured using fluorescence-based assays. Apoptotic cells were detected by Hoechst 33342 and Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) double staining; protein expression was detected by Western blotting. TGZ inhibited cell proliferation in a dose-dependent manner in both cell lines, and the effect was not suppressed by a PPARγ inhibitor. Additionally, TGZ increased apoptotic cell number and upregulated p38 and c-Jun N-terminal kinase (JNK) phosphorylation; however, p38 and JNK inhibitors did not block TGZ-mediated inhibition of cell proliferation in either cell line. TGZ also upregulated extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation, whereas an ERK1/2 inhibitor enhanced TGZ-mediated cytotoxicity in A549 cells. Additionally, TGZ increased LC3-II expression, and chloroquine (an autophagy inhibitor) attenuated TGZ-mediated inhibition of cell proliferation. These findings suggest that TGZ-induced inhibition of cell proliferation is PPARγ independent. TGZ-mediated inhibition of cell proliferation was accompanied by apoptosis and independent of the MAPK signaling pathway. These results suggest that TGZ inhibits cell proliferation through autophagy-induced cytotoxicity. This study demonstrated that chemotherapy using TGZ may be effective for lung adenocarcinoma.
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Affiliation(s)
- Yoshie Tsujiya
- Department of Clinical Pharmacy, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University
| | - Ai Hasegawa
- Department of Clinical Pharmacy, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University
| | - Motohiro Yamamori
- Department of Clinical Pharmacy, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University
| | - Noboru Okamura
- Department of Clinical Pharmacy, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University
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3
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Xu R, Luo X, Ye X, Li H, Liu H, Du Q, Zhai Q. SIRT1/PGC-1α/PPAR-γ Correlate With Hypoxia-Induced Chemoresistance in Non-Small Cell Lung Cancer. Front Oncol 2021; 11:682762. [PMID: 34381712 PMCID: PMC8351465 DOI: 10.3389/fonc.2021.682762] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 06/30/2021] [Indexed: 12/18/2022] Open
Abstract
Resistance is the major cause of treatment failure and disease progression in non-small cell lung cancer (NSCLC). There is evidence that hypoxia is a key microenvironmental stress associated with resistance to cisplatin, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), and immunotherapy in solid NSCLCs. Numerous studies have contributed to delineating the mechanisms underlying drug resistance in NSCLC; nevertheless, the mechanisms involved in the resistance associated with hypoxia-induced molecular metabolic adaptations in the microenvironment of NSCLC remain unclear. Studies have highlighted the importance of posttranslational regulation of molecular mediators in the control of mitochondrial function in response to hypoxia-induced metabolic adaptations. Hypoxia can upregulate the expression of sirtuin 1 (SIRT1) in a hypoxia-inducible factor (HIF)-dependent manner. SIRT1 is a stress-dependent metabolic sensor that can deacetylate some key transcriptional factors in both metabolism dependent and independent metabolic pathways such as HIF-1α, peroxisome proliferator-activated receptor gamma (PPAR-γ), and PPAR-gamma coactivator 1-alpha (PGC-1α) to affect mitochondrial function and biogenesis, which has a role in hypoxia-induced chemoresistance in NSCLC. Moreover, SIRT1 and HIF-1α can regulate both innate and adaptive immune responses through metabolism-dependent and -independent ways. The objective of this review is to delineate a possible SIRT1/PGC-1α/PPAR-γ signaling-related molecular metabolic mechanism underlying hypoxia-induced chemotherapy resistance in the NSCLC microenvironment. Targeting hypoxia-related metabolic adaptation may be an attractive therapeutic strategy for overcoming chemoresistance in NSCLC.
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Affiliation(s)
- Rui Xu
- Department of Pharmacy, Fudan University Shanghai Cancer Center, Minhang Branch, Shanghai, China
| | - Xin Luo
- Department of Pharmacy, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Xuan Ye
- Department of Pharmacy, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Huan Li
- Department of Pharmacy, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Hongyue Liu
- Department of Pharmacy, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Qiong Du
- Department of Pharmacy, Fudan University Shanghai Cancer Center, Minhang Branch, Shanghai, China.,Department of Pharmacy, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Qing Zhai
- Department of Pharmacy, Fudan University Shanghai Cancer Center, Minhang Branch, Shanghai, China.,Department of Pharmacy, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
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Exploring conformational changes of PPAR-Ɣ complexed with novel kaempferol, quercetin, and resveratrol derivatives to understand binding mode assessment: a small-molecule checkmate to cancer therapy. J Mol Model 2020; 26:242. [DOI: 10.1007/s00894-020-04488-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 07/27/2020] [Indexed: 12/11/2022]
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5
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Ory V, Kietzman WB, Boeckelman J, Kallakury BV, Wellstein A, Furth PA, Riegel AT. The PPARγ agonist efatutazone delays invasive progression and induces differentiation of ductal carcinoma in situ. Breast Cancer Res Treat 2018; 169:47-57. [PMID: 29350308 DOI: 10.1007/s10549-017-4649-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 12/26/2017] [Indexed: 02/06/2023]
Abstract
PURPOSE Ductal carcinoma in situ (DCIS) is a pre-invasive lesion of the breast considered a precursor of invasive ductal carcinoma. This study aimed to determine whether activated PPARγ acts as a tumor suppressor in human DCIS progression. METHODS We utilized the high-affinity PPARγ agonist, efatutazone, to activate endogenous PPARγ in a well-defined model for the progression of basal (triple negative) DCIS, MCFDCIS cells, cultured under 2D and 3D conditions. We studied the effects of activated PPARγ on DCIS progression in MCFDCIS xenograft and C3(1)/Tag transgenic mice treated with 30 mg/kg of efatutazone. RESULTS In vitro, efatutazone did not alter the MCFDCIS cell proliferation but induced phenotypic and gene expression changes, indicating that activated PPARγ is able to differentiate MCFDCIS cells into more luminal and lactational-like cells. In addition, MCFDCIS tumorsphere formation in 3D was reduced by PPARγ activation. In vivo, efatutazone-treated MCFDCIS tumors exhibited fat deposition along with upregulation of PPARγ responsive genes in both epithelial and stromal compartments, suggesting features of milk-producing mammary epithelial cell differentiation. The efatutazone-treated lesions were less invasive with fewer CD44+/p63+ basal progenitor cells. PPARγ activation downregulated Akt phosphorylation in these tumors, although the ERK pathway remained unchanged. Similar trends in gene expression changes consistent with lactational and luminal cell differentiation were observed in the C3(1)/Tag mouse model after efatutazone treatment. CONCLUSIONS Our data suggest that activation of the PPARγ pathway differentiates DCIS lesions and may be a useful approach to delay DCIS progression.
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Affiliation(s)
- Virginie Ory
- Department of Oncology, Georgetown University, Washington, DC, USA.
| | | | - Jacob Boeckelman
- Department of Oncology, Georgetown University, Washington, DC, USA
| | - Bhaskar V Kallakury
- Department of Pathology, Georgetown University, Washington, DC, USA.,The Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA
| | - Anton Wellstein
- Department of Oncology, Georgetown University, Washington, DC, USA.,The Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA
| | - Priscilla A Furth
- Department of Oncology, Georgetown University, Washington, DC, USA.,Department of Medicine, Georgetown University, Washington, DC, USA.,The Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA
| | - Anna T Riegel
- Department of Oncology, Georgetown University, Washington, DC, USA.,The Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC, USA
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6
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Jin Z, Jia B, Fu Y, Tan L, Chen Q, Jiang P, Liu Y. Ligands of the peroxisome proliferator-activated receptor γ inhibit hepatoce llular carcinoma cell proliferation. Oncol Lett 2017; 14:4767-4771. [PMID: 28943966 PMCID: PMC5594240 DOI: 10.3892/ol.2017.6731] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 07/05/2017] [Indexed: 01/05/2023] Open
Abstract
This study was designed to investigate the regulatory role of the peroxisome proliferator-activated receptor γ (PPARγ) in the growth of hepatocellular carcinoma cells under the hypothesis that the levels of the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) mRNA and the phosphorylated Akt (pAkt) protein would be affected by the presence of different receptor ligand concentrations. SMMC-7721 hepatocellular carcinoma cells were cultured in the presence of different concentrations of either 15-deoxyprostaglandin J2 (15-d-PGJ2) or pioglitazone and experiments were conducted in order to determine cell growth changes and measure levels of PTEN mRNA and pAkt protein. Our results after treatment with MTT showed the addition of ligands to the cultured cells inhibited their proliferation in a time- and dose-dependent manner. Also, flow cytometry after PI treatment showed the presence of ligands in the growth media could increase the proportion of G0/G1 phase cells, and decrease the proportion of S phase cells. Finally, the same cells exhibited increased levels of the PTEN mRNA by RT-PCR and pAkt protein by western blot analysis. Taken together, our results support the notion that PPARγ ligands can inhibit the proliferation of hepatocellular carcinoma cells in a time- and dose-dependent manner, and that this is at least in part due to the resulting upregulation of PTEN expression.
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Affiliation(s)
- Zhe Jin
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Baoxing Jia
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yu Fu
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Ludong Tan
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Qingmin Chen
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Peiqiang Jiang
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
| | - Yahui Liu
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China
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7
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PPAR γ as a Novel Therapeutic Target in Lung Cancer. PPAR Res 2016; 2016:8972570. [PMID: 27698657 PMCID: PMC5028876 DOI: 10.1155/2016/8972570] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 08/07/2016] [Indexed: 02/08/2023] Open
Abstract
Lung cancer is the leading cause of cancer-related death, with more than half the patients having advanced-stage disease at the time of initial diagnosis and thus facing a poor prognosis. This dire situation poses a need for new approaches in prevention and treatment. Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily. Its involvement in adipocyte differentiation and glucose and lipid homeostasis is well-recognized, but accumulating evidence now suggests that PPARγ may also function as a tumor suppressor, inhibiting development of primary tumors and metastases in lung cancer and other malignancies. Besides having prodifferentiation, antiproliferative, and proapoptotic effects, PPARγ agonists have been shown to prevent cancer cells from acquiring the migratory and invasive capabilities essential for successful metastasis. Angiogenesis and secretion of certain matrix metalloproteinases and extracellular matrix proteins within the tumor microenvironment are also regulated by PPARγ. This review of the current literature highlights the potential of PPARγ agonists as novel therapeutic modalities in lung cancer, either as monotherapy or in combination with standard cytotoxic chemotherapy.
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8
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Li MY, Yuan HL, Ko FWS, Wu B, Long X, Du J, Wu J, Ng CSH, Wan IYP, Mok TSK, Hui DSC, Underwood MJ, Chen GG. Antineoplastic effects of 15(S)-hydroxyeicosatetraenoic acid and 13-S-hydroxyoctadecadienoic acid in non-small cell lung cancer. Cancer 2015; 121 Suppl 17:3130-45. [PMID: 26331820 DOI: 10.1002/cncr.29547] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 05/22/2015] [Accepted: 05/26/2015] [Indexed: 12/28/2022]
Abstract
BACKGROUND Previous studies have shown that the levels of 15-lipoxygenase 1 (15-LOX-1) and 15-LOX-2 as well as their metabolites 13-S-hydroxyoctadecadienoic acid (13(S)-HODE) and 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE) are significantly reduced in smokers with non-small cell lung carcinoma (NSCLC). Furthermore, animal model experiments have indicated that the reduction of these molecules occurs before the establishment of cigarette smoking carcinogen-induced lung tumors, and this suggests roles in lung tumorigenesis. However, the functions of these molecules remain unknown in NSCLC. METHODS NSCLC cells were treated with exogenous 13(S)-HODE and 15(S)-HETE, and then the ways in which they affected cell function were examined. 15-LOX-1 and 15-LOX-2 were also overexpressed in tumor cells to restore these 2 enzymes to generate endogenous 13(S)-HODE and 15(S)-HETE before cell function was assessed. RESULTS The application of exogenous 13(S)-HODE and 15(S)-HETE significantly enhanced the activity of peroxisome proliferator-activated receptor γ (PPARγ), inhibited cell proliferation, induced apoptosis, and activated caspases 9 and 3. The overexpression of 15-LOX-1 and 15-LOX-2 obviously promoted the endogenous levels of 13(S)-HODE and 15(S)-HETE, which were demonstrated to be more effective in the inhibition of NSCLC. CONCLUSIONS This study has demonstrated that exogenous or endogenous 13(S)-HODE and 15(S)-HETE can functionally inhibit NSCLC, likely by activating PPARγ. The restoration of 15-LOX activity to increase the production of endogenous 15(S)-HETE and 13(S)-HODE may offer a novel research direction for molecular targeting treatment of smoking-related NSCLC. This strategy can potentially avoid side effects associated with the application of synthetic PPARγ ligands.
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Affiliation(s)
- Ming-Yue Li
- Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Hui-Ling Yuan
- Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, People's Republic of China.,Department of Breast Surgery, Dongguan People's Hospital, Dongguan, People's Republic of China
| | - Fanny W S Ko
- Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Bin Wu
- Department of Respiratory Medicine, Affiliated Hospital of Guang Dong Medical College, Zhanjiang, People's Republic of China
| | - Xiang Long
- Shenzhen Hospital, Peking University, Shenzhen, People's Republic of China
| | - Jing Du
- Shenzhen Hospital, Peking University, Shenzhen, People's Republic of China
| | - Jun Wu
- Department of Respiratory Medicine, Affiliated Hospital of Guang Dong Medical College, Zhanjiang, People's Republic of China
| | - Calvin S H Ng
- Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Innes Y P Wan
- Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Tony S K Mok
- Department of Clinical Oncology, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - David S C Hui
- Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Malcolm J Underwood
- Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - George G Chen
- Department of Surgery, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, People's Republic of China
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Hou G, Yin Y, Han D, Wang QY, Kang J. Rosiglitazone attenuates the metalloprotease/anti-metalloprotease imbalance in emphysema induced by cigarette smoke: involvement of extracellular signal-regulated kinase and NFκB signaling. Int J Chron Obstruct Pulmon Dis 2015; 10:715-24. [PMID: 25897215 PMCID: PMC4396520 DOI: 10.2147/copd.s77514] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Objective We investigated how rosiglitazone attenuated cigarette smoke (CS)-induced emphysema in a rat model. In particular, we focused on its possible effects on the imbalance between metalloprotease (MMP) and anti-MMP activity, mitogen-activated protein kinase (MAPK) phosphorylation, and nuclear factor kappa-light-chain-enhancer of activated B cell (NFκB) signaling pathway over-activation. Methods A total of 36 Wistar rats were divided into three groups (n=12 each): animals were exposed to CS for 12 weeks in the absence (the CS group) or presence of 30 mg/kg rosiglitazone (the rosiglitazone-CS [RCS] group); a control group was treated with the rosiglitazone vehicle only, without any CS exposure. Histopathology of lung tissue in all groups was evaluated to grade severity of the disease. Expression levels of peroxisome proliferator-activated receptor γ (PPARγ), MMP2, and MMP9 in lung tissue were determined and compared using Western blotting and immunohistochemistry. Activation of MAPKs, NFκB, and the nuclear factor of kappa light polypeptide gene enhancer in B-cell inhibitor, alpha (IκBα) phosphorylation in lung tissue was examined by Western blotting. Results Emphysema-related pathology, based on inter-alveolar wall distance and alveolar density, was less severe in the RCS group than in the CS group. Compared with the CS group, levels of PPARγ were higher in the RCS group, and levels of MMP2 and MMP9 proteins were lower in the RCS rats. Levels of activated MAPKs and NFκB were also lower, while the IκBαphosphorylation was increased in the lung tissue of RCS rats. Conclusion Our findings suggest that oral administration of rosiglitazone attenuates the metalloprotease activity induced by CS, and the underlying mechanism might involve the activation of signaling pathways dependent on MAPKs or NFκB. Our results further suggest that PPARγ contributes to the pathogenesis of emphysema as well as airway inflammation induced by CS.
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Affiliation(s)
- Gang Hou
- Department of Respiratory Medicine, the First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Yan Yin
- Department of Respiratory Medicine, the First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Dan Han
- Department of Respiratory Medicine, the First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Qiu-Yue Wang
- Department of Respiratory Medicine, the First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Jian Kang
- Department of Respiratory Medicine, the First Hospital of China Medical University, Shenyang, People's Republic of China
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10
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Kasala ER, Bodduluru LN, Madana RM, V AK, Gogoi R, Barua CC. Chemopreventive and therapeutic potential of chrysin in cancer: mechanistic perspectives. Toxicol Lett 2015; 233:214-25. [DOI: 10.1016/j.toxlet.2015.01.008] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 01/08/2015] [Accepted: 01/13/2015] [Indexed: 02/07/2023]
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12
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Chen HM, Zhang DG, Wu JX, Pei DS, Zheng JN. Ubiquitination of p53 is involved in troglitazone induced apoptosis in cervical cancer cells. Asian Pac J Cancer Prev 2014; 15:2313-8. [PMID: 24716976 DOI: 10.7314/apjcp.2014.15.5.2313] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Peroxisome proliferator-activated receptor gamma (PPAR-γ), a ligand-dependent nuclear transcription factor, has been found to widely exist in tumor tissues and plays an important role in affecting tumor cell growth. In this study, we investigated the effect of PPAR-γ on aspects of the cervical cancer malignant phenotype, such as cell proliferation and apoptosis. Cell growth assay, Western blotting, Annexin V and flow cytometry analysis consistently showed that treatment with troglitazone (TGZ, a PPAR-γ agonist) led to dose-dependent inhibition of cervical cancer cell growth through apoptosis, whereas T0070907 (another PPAR-γ antagonist???) had no effect on Hela cell proliferation and apoptosis. Furthermore, we also detected the protein expression of p53, p21 and Mdm2 to explain the underlying mechanism of PPAR-γ on cellular apoptosis. Our work, finally, demonstrated the existence of the TGZ-PPAR-γ-p53 signaling pathway to be a critical regulator of cell apoptosis. These results suggested that PPAR-γ may be a potential therapeutic target for cervical cancer.
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Affiliation(s)
- Hui-Min Chen
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, Xuzhou, China E-mail : ;
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13
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Nikhil K, Sharan S, Singh AK, Chakraborty A, Roy P. Anticancer activities of pterostilbene-isothiocyanate conjugate in breast cancer cells: involvement of PPARγ. PLoS One 2014; 9:e104592. [PMID: 25119466 PMCID: PMC4131888 DOI: 10.1371/journal.pone.0104592] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 07/15/2014] [Indexed: 01/17/2023] Open
Abstract
Trans-3,5-dimethoxy-4'-hydroxystilbene (PTER), a natural dimethylated analog of resveratrol, preferentially induces certain cancer cells to undergo apoptosis and could thus have a role in cancer chemoprevention. Peroxisome proliferator-activated receptor γ (PPARγ), a member of the nuclear receptor superfamily, is a ligand-dependent transcription factor whose activation results in growth arrest and/or apoptosis in a variety of cancer cells. Here we investigated the potential of PTER-isothiocyanate (ITC) conjugate, a novel class of hybrid compound (PTER-ITC) synthesized by appending an ITC moiety to the PTER backbone, to induce apoptotic cell death in hormone-dependent (MCF-7) and -independent (MDA-MB-231) breast cancer cell lines and to elucidate PPARγ involvement in PTER-ITC action. Our results showed that when pre-treated with PPARγ antagonists or PPARγ siRNA, both breast cancer cell lines suppressed PTER-ITC-induced apoptosis, as determined by annexin V/propidium iodide staining and cleaved caspase-9 expression. Furthermore, PTER-ITC significantly increased PPARγ mRNA and protein levels in a dose-dependent manner and modulated expression of PPARγ-related genes in both breast cancer cell lines. This increase in PPARγ activity was prevented by a PPARγ-specific inhibitor, in support of our hypothesis that PTER-ITC can act as a PPARγ activator. PTER-ITC-mediated upregulation of PPARγ was counteracted by co-incubation with p38 MAPK or JNK inhibitors, suggesting involvement of these pathways in PTER-ITC action. Molecular docking analysis further suggested that PTER-ITC interacted with 5 polar and 8 non-polar residues within the PPARγ ligand-binding pocket, which are reported to be critical for its activity. Collectively, our observations suggest potential applications for PTER-ITC in breast cancer prevention and treatment through modulation of the PPARγ activation pathway.
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Affiliation(s)
- Kumar Nikhil
- Molecular Endocrinology Laboratory, Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India
| | - Shruti Sharan
- Molecular Endocrinology Laboratory, Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India
| | - Abhimanyu K. Singh
- Department of Macromolecular Structures, Centro Nacional de Biotecnologia (CNB-CSIC), Campus de Cantoblanco, Madrid, Spain
| | - Ajanta Chakraborty
- Molecular Endocrinology Laboratory, Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India
| | - Partha Roy
- Molecular Endocrinology Laboratory, Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India
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14
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Heller ER, Gor A, Wang D, Hu Q, Lucchese A, Kanduc D, Katdare M, Liu S, Sinha AA. Molecular signatures of basal cell carcinoma susceptibility and pathogenesis: a genomic approach. Int J Oncol 2012; 42:583-96. [PMID: 23229765 DOI: 10.3892/ijo.2012.1725] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2012] [Accepted: 10/22/2012] [Indexed: 11/06/2022] Open
Abstract
Gene expression profiling can be useful for phenotypic classification, investigation of functional pathways, and to facilitate the search for disease risk genes through the integration of transcriptional data with available genomic information. To enhance our understanding of the genetic and molecular basis of basal cell carcinoma (BCC) we performed global gene expression analysis to generate a disease-associated transcriptional profile. A gene signature composed of 331 differentially expressed genes (DEGs) was generated from comparing 4 lesional and 4 site-matched control samples using Affymetrix Human Genome U95A microarrays. Hierarchical clustering based on the obtained gene signature separated the samples into their corresponding phenotype. Pathway analysis identified several significantly overrepresented pathways including PPAR-γ signaling, TGF-β signaling and lipid metabolism, as well as confirmed the importance of SHH and p53 in the pathogenesis of BCC. Comparison of our microarray data with previous microarray studies revealed 13 DEGs overlapping in 3 studies. Several of these overlapping genes function in lipid metabolism or are components of the extracellular matrix, suggesting the importance of these and related pathways in BCC pathogenesis. BCC-associated DEGs were mapped to previously reported BCC susceptibility loci including 1p36, 1q42, 5p13.3, 5p15 and 12q11-13. Our analysis also revealed transcriptional 'hot spots' on chromosome 5 which help to confirm (5p13 and 5p15) and suggest novel (5q11.2-14.3, 5q22.1-23.3 and 5q31-35.3) disease susceptibility loci/regions. Integrating microarray analyses with reported genetic information helps to confirm and suggest novel disease susceptibility loci/regions. Identification of these specific genomic and/or transcriptional targets may lead to novel diagnostic and therapeutic modalities.
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Affiliation(s)
- Elizabeth Rose Heller
- Department of Dermatology, State University of New York at Buffalo and Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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15
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Susaki Y, Inoue M, Minami M, Sawabata N, Shintani Y, Nakagiri T, Funaki S, Aozasa K, Okumura M, Morii E. Inhibitory effect of PPARγ on NR0B1 in tumorigenesis of lung adenocarcinoma. Int J Oncol 2012; 41:1278-84. [PMID: 22843091 DOI: 10.3892/ijo.2012.1571] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 05/18/2012] [Indexed: 11/05/2022] Open
Abstract
NR0B1, an orphan nuclear receptor, is expressed in side population cells and its knockdown reduces tumorigenic and anti-apoptotic potential in lung adenocarcinoma. Peroxisome proliferator-activated receptor γ (PPARγ) is another member of the nuclear receptor family which induces apoptosis in lung cancer. The interaction of NR0B1 with PPARγ was examined. The transactivation ability of PPARγ was inhibited by NR0B1 in lung adenocarcinoma, and the N-terminal region of NR0B1 containing LxxLL motifs mediated its inhibition. Co-immunoprecipitation experiments revealed that this N-terminal region of NR0B1 was essential for the physical interaction with PPARγ. Aldehyde dehydrogenase (ALDH) activity and ALDH3A1 expression, which are correlated with tumorigenic potential of lung adenocarcinoma, increased when NR0B1 expression was induced, but its increase was inhibited by PPARγ overexpression. ALDH activity increased by treatment with PPARγ inhibitor, and the increase was further enhanced when the expression of NR0B1 was induced. Furthermore, the high NR0B1 and low PPARγ expression was a negative prognostic factor in Pathological-Stage IA clinical cases. These results indicate the reciprocal relationship between NR0B1 and PPARγ on the malignant grade of lung adenocarcinoma.
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Affiliation(s)
- Yoshiyuki Susaki
- Department of Pathology, Osaka University Graduate School of Medicine, Suita 565-0871, Japan
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16
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An Z, Liu X, Song H, Choi C, Kim WD, Yu JR, Park WY. Effect of troglitazone on radiation sensitivity in cervix cancer cells. Radiat Oncol J 2012; 30:78-87. [PMID: 22984686 PMCID: PMC3429892 DOI: 10.3857/roj.2012.30.2.78] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 04/26/2012] [Accepted: 05/10/2012] [Indexed: 01/19/2023] Open
Abstract
Purpose Troglitazone (TRO) is a peroxisome proliferator-activated receptor γ (PPARγ) agonist. TRO has antiproliferative activity on many kinds of cancer cells via G1 arrest. TRO also increases Cu2+/Zn2+-superoxide dismutase (CuZnSOD) and catalase. Cell cycle, and SOD and catalase may affect on radiation sensitivity. We investigated the effect of TRO on radiation sensitivity in cancer cells in vitro. Materials and Methods Three human cervix cancer cell lines (HeLa, Me180, and SiHa) were used. The protein expressions of SOD and catalase, and catalase activities were measured at 2-10 µM of TRO for 24 hours. Cell cycle was evaluated with flow cytometry. Reactive oxygen species (ROS) was measured using 2',7'-dichlorofluorescin diacetate. Cell survival by radiation was measured with clonogenic assay. Results By 5 µM TRO for 24 hours, the mRNA, protein expression and activity of catalase were increased in all three cell lines. G0-G1 phase cells were increased in HeLa and Me180 by 5 µM TRO for 24 hours, but those were not increased in SiHa. By pretreatment with 5 µM TRO radiation sensitivity was increased in HeLa and Me180, but it was decreased in SiHa. In Me180, with 2 µM TRO which increased catalase but not increased G0-G1 cells, radiosensitization was not observed. ROS produced by radiation was decreased with TRO. Conclusion TRO increases radiation sensitivity through G0-G1 arrest or decreases radiation sensitivity through catalase-mediated ROS scavenging according to TRO dose or cell types. The change of radiation sensitivity by combined with TRO is not dependent on the PPARγ expression level.
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Affiliation(s)
- Zhengzhe An
- Department of Radiation Oncology, Chungbuk National University College of Medicine, Cheongju, Korea
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17
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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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Peroxisome proliferator-activated receptor δ confers resistance to peroxisome proliferator-activated receptor γ-induced apoptosis in colorectal cancer cells. Oncogene 2011; 31:1013-23. [PMID: 21765467 DOI: 10.1038/onc.2011.299] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) may serve as a useful target for drug development in non-diabetic diseases. However, some colorectal cancer cells are resistant to PPARγ agonists by mechanisms that are poorly understood. Here, we provide the first evidence that elevated PPARδ expression and/or activation of PPARδ antagonize the ability of PPARγ to induce colorectal carcinoma cell death. More importantly, the opposing effects of PPARδ and PPARγ in regulating programmed cell death are mediated by survivin and caspase-3. We found that activation of PPARγ results in decreased survivin expression and increased caspase-3 activity, whereas activation of PPARδ counteracts these effects. Our findings suggest that PPARδ and PPARγ coordinately regulate cancer cell fate by controlling the balance between the cell death and survival and demonstrate that inhibition of PPARδ can reprogram PPARγ ligand-resistant cells to respond to PPARγ agonists.
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20
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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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Han S, Zheng Y, Roman J. Rosiglitazone, an Agonist of PPARgamma, Inhibits Non-Small Cell Carcinoma Cell Proliferation In Part through Activation of Tumor Sclerosis Complex-2. PPAR Res 2011; 2007:29632. [PMID: 17597835 PMCID: PMC1892639 DOI: 10.1155/2007/29632] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Revised: 03/21/2007] [Accepted: 03/27/2007] [Indexed: 12/31/2022] Open
Abstract
PPARγ ligands inhibit the proliferation of non-small cell lung carcinoma (NSCLC) cells in vitro. The mechanisms responsible for this effect remain incompletely elucidated, but PPARγ ligands appear to inhibit the mammalian target of rapamycin (mTOR) pathway. We set out to test the hypothesis that PPARγ ligands activate tuberous sclerosis complex-2 (TSC2), a tumor suppressor gene that inhibits mTOR signaling. We found that the PPARγ ligand rosiglitazone stimulated the phosphorylation of TSC2 at serine-1254, but not threonine-1462. However, an antagonist of PPARγ and PPARγ siRNA did not inhibit these effects. Rosiglitazone also increased the phosphorylation of p38 MAPK, but inhibitors of p38 MAPK and its downstream signal MK2 had no effect on rosiglitazone-induced activation of TSC2. Activation of TSC2 resulted in downregulation of phosphorylated p70S6K, a downstream target of mTOR. A TSC2 siRNA induced p70S6K phosphorylation at baseline and inhibited p70S6K downregulation by rosiglitazone. When compared to a control siRNA in a thymidine incorporation assay, the TSC2 siRNA reduced the growth inhibitory effect of rosiglitazone by fifty percent. These observations suggest that rosiglitazone inhibits NSCLC growth partially through phosphorylation of TSC2 via PPARγ-independent pathways.
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Affiliation(s)
- ShouWei Han
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Department of Obstetrics and Gynecology, West China 2nd University Hospital, Sichuan University, Chengdu 610041, China
- *ShouWei Han:
| | - Ying Zheng
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Department of Obstetrics and Gynecology, West China 2nd University Hospital, Sichuan University, Chengdu 610041, China
| | - Jesse Roman
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Emory University School of Medicine, Emory University, Atlanta, GA 30322, USA
- Atlanta Veterans Affairs Medical Center, Emory University, Atlanta, GA 30033, USA
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Reka AK, Goswami MT, Krishnapuram R, Standiford TJ, Keshamouni VG. Molecular cross-regulation between PPAR-γ and other signaling pathways: implications for lung cancer therapy. Lung Cancer 2011; 72:154-9. [PMID: 21354647 DOI: 10.1016/j.lungcan.2011.01.019] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 01/23/2011] [Indexed: 11/16/2022]
Abstract
Peroxisome proliferator-activated receptors (PPAR)-γ belongs to the nuclear hormone receptor superfamily of ligand-dependent transcription factors. It is a mediator of adipocyte differentiation, regulates lipid metabolism and macrophage function. The ligands of PPAR-γ have long been in the clinic for the treatment of type II diabetes and have a very low toxicity profile. Activation of PPAR-γ was shown to modulate various hallmarks of cancer through its pleiotropic affects on multiple different cell types in the tumor microenvironment. An overwhelming number of preclinical-studies demonstrate the efficacy of PPAR-γ ligands in the control of tumor progression through their affects on various cellular processes, including cell proliferation, apoptosis, angiogenesis, inflammation and metastasis. A variety of signaling pathways have been implicated as potential mechanisms of action. This review will focus on the molecular basis of these mechanisms; primarily PPAR-γ cross-regulation with other signaling pathways and its relevance to lung cancer therapy will be discussed.
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Affiliation(s)
- Ajaya Kumar Reka
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
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24
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Li MY, Leung J, Kong AWY, Liang NC, Wu K, Hsin MKY, Deng YF, Gong X, Lv Y, Mok TSK, Underwood MJ, Chen GG. Anticancer efficacy of 5F in NNK-induced lung cancer development of A/J mice and human lung cancer cells. J Mol Med (Berl) 2010; 88:1265-76. [DOI: 10.1007/s00109-010-0676-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 07/29/2010] [Accepted: 08/13/2010] [Indexed: 12/19/2022]
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Chen Q, Zhou J, Jiang C, Chen J. Reversal of P-glycoprotein-mediated multidrug resistance in SGC7901/VCR cells by PPARγ activation by troglitazone. ACTA ACUST UNITED AC 2010; 30:326-31. [DOI: 10.1007/s11596-010-0351-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2009] [Indexed: 11/29/2022]
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Wang J, Wang Y, Wong C. Oestrogen-related receptor alpha inverse agonist XCT-790 arrests A549 lung cancer cell population growth by inducing mitochondrial reactive oxygen species production. Cell Prolif 2010; 43:103-13. [PMID: 20447055 PMCID: PMC6495589 DOI: 10.1111/j.1365-2184.2009.00659.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Accepted: 05/15/2009] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE Although oestrogen-related receptor alpha (ERRalpha) is primarily thought to regulate energy homeostasis, it also serves as a prognostic marker for cancer. The aim of this study was to investigate any connection between ERRalpha activity and cell population growth. MATERIALS AND METHODS XCT-790, an ERRa specific inverse agonist, was employed to suppress ERRa activity in human non-small cell lung cancer cells (NSCLC) A549. Gene expressions were detected using quantitative real-time PCR and Western blot analysis. Mitochondrial mass, membrane potential and reactive oxygen species (ROS) production were measured by staining with Mitotracker green, JC-1 and CM-H(2)DCFDA dyes respectively. Rate of progression through the tricarboxylic acid (TCA) cycle was analysed by measuring activities of citrate synthase and succinate dehydrogenase. Cell cycle analysis was performed by using flow cytometry. RESULTS We found that XCT-790 treatment reduced mitochondrial mass but enhanced mitochondrial ROS production by increasing rate through the TCA cycle, elevating mitochondrial membrane potential (DeltaPsi(m)) and down-regulating expression of superoxide dismutase. It was further demonstrated that XCT-790-induced ROS modulated p53 and Rb signalling pathways and suppressed cell replication. CONCLUSIONS ERRalpha affects cell cycle mechanisms through modulating mitochondrial mass and function. Dysregulation of this essential pathway leads to elevation in mitochondrial ROS production, which in turn modulates activities of tumour suppressors, resulting in cell cycle arrest.
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Affiliation(s)
- J. Wang
- Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Y. Wang
- Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - C. Wong
- Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
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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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Yoshizaki T, Motomura W, Tanno S, Kumei S, Yoshizaki Y, Tanno S, Okumura T. Thiazolidinediones enhance vascular endothelial growth factor expression and induce cell growth inhibition in non-small-cell lung cancer cells. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2010; 29:22. [PMID: 20214829 PMCID: PMC2851675 DOI: 10.1186/1756-9966-29-22] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Accepted: 03/10/2010] [Indexed: 01/13/2023]
Abstract
Background It is known that thiazolidinediones are involved in regulating the expression of various genes, including the vascular endothelial growth factor (VEGF) gene via peroxisome proliferator-activated receptor γ (PPARγ); VEGF is a prognostic biomarker for non-small-cell lung cancer (NSCLC). Methods In this study, we investigated the effects of troglitazone and ciglitazone on the mRNA expression of VEGF and its receptors in human NSCLC cell lines, RERF-LC-AI, SK-MES-1, PC-14, and A549. These mRNA expressions were evaluated by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. We also studied the effect of Je-11, a VEGF inhibitor, on the growth of these cells. Results In NSCLC cells, thiazolidinediones increased the mRNA expression of VEGF and neuropilin-1, but not that of other receptors such as fms-like tyrosine kinase and kinase insert domain receptor-1. Furthermore, the PPARγ antagonist GW9662 completely reversed this thiazolidinedione-induced increase in VEGF expression. Furthermore, the addition of VEGF inhibitors into the culture medium resulted in the reversal of thiazolidinedione-induced growth inhibition. Conclusions Our results indicated that thiazolidinediones enhance VEGF and neuropilin-1 expression and induce the inhibition of cell growth. We propose the existence of a pathway for arresting cell growth that involves the interaction of thiazolidinedione-induced VEGF and neuropilin-1 in NSCLC.
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Affiliation(s)
- Takayuki Yoshizaki
- Innovation Center, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan.
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Gromyko D, Arnesen T, Ryningen A, Varhaug JE, Lillehaug JR. Depletion of the human Nα-terminal acetyltransferase A induces p53-dependent apoptosis and p53-independent growth inhibition. Int J Cancer 2010; 127:2777-89. [DOI: 10.1002/ijc.25275] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Li MY, Hsin MKY, Yip J, Mok TSK, Underwood MJ, Chen GG. PPARγ Activation Extinguishes Smoking Carcinogen by Inhibiting NNK-Mediated Proliferation. Am J Respir Cell Mol Biol 2010; 42:113-22. [DOI: 10.1165/rcmb.2008-0463oc] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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Campbell SE, Musich PR, Whaley SG, Stimmel JB, Leesnitzer LM, Dessus-Babus S, Duffourc M, Stone W, Newman RA, Yang P, Krishnan K. Gamma Tocopherol Upregulates the Expression of 15-S-HETE and Induces Growth Arrest Through a PPAR Gamma-Dependent Mechanism in PC-3 Human Prostate Cancer Cells. Nutr Cancer 2009; 61:649-62. [DOI: 10.1080/01635580902825654] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Belfiore A, Genua M, Malaguarnera R. PPAR-γ agonists and their effects on IGF-I receptor signaling: Implications for cancer. PPAR Res 2009; 2009:830501. [PMID: 19609453 PMCID: PMC2709717 DOI: 10.1155/2009/830501] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2009] [Accepted: 05/04/2009] [Indexed: 01/04/2023] Open
Abstract
It is now well established that the development and progression of a variety of human malignancies are associated with dysregulated activity of the insulin-like growth factor (IGF) system. In this regard, promising drugs have been developed to target the IGF-I receptor or its ligands. These therapies are limited by the development of insulin resistance and compensatory hyperinsulinemia, which in turn, may stimulate cancer growth. Novel therapeutic approaches are, therefore, required. Synthetic PPAR-γ agonists, such as thiazolidinediones (TZDs), are drugs universally used as antidiabetic agents in patients with type 2 diabetes. In addition of acting as insulin sensitizers, PPAR-γ agonists mediate in vitro and in vivo pleiotropic anticancer effects. At least some of these effects appear to be linked with the downregulation of the IGF system, which is induced by the cross-talk of PPAR-γ agonists with multiple components of the IGF system signaling. As hyperinsulinemia is an emerging cancer risk factor, the insulin lowering action of PPAR-γ agonists may be expected to be also beneficial to reduce cancer development and/or progression. In light of these evidences, TZDs or other PPAR-γ agonists may be exploited in those tumors "addicted" to the IGF signaling and/or in tumors occurring in hyperinsulinemic patients.
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Affiliation(s)
- A Belfiore
- Endocrinology Unit, Department of Clinical and Experimental Medicine, University of Catanzaro, 88100 Catanzaro, Italy.
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Tan XW, Xia H, Xu JH, Cao JG. Induction of apoptosis in human liver carcinoma HepG2 cell line by 5-allyl-7-gen-difluoromethylenechrysin. World J Gastroenterol 2009; 15:2234-9. [PMID: 19437563 PMCID: PMC2682238 DOI: 10.3748/wjg.15.2234] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of 5-allyl-7-gen-difluoromethylenechrysin (ADFMChR) on apoptosis of human liver carcinoma HepG2 cell line and the molecular mechanisms involved.
METHODS: HepG2 cells and L-02 cells were cultured in vitro and the inhibitory effect of ADFMChR on their proliferation was measured by MTT assay. The apoptosis of HepG2 cells was determined by flow cytometry (FCM) using propidium iodide (PI) fluorescence staining. DNA ladder bands were observed by DNA agarose gel electrophoresis. The influence of ADFMChR on the proxisome proliferator-activated receptor γ (PPARγ), NF-κB, Bcl-2 and Bax protein expression of HepG2 cells were analyzed by Western blotting.
RESULTS: MTT assay showed that ADFMChR significantly inhibited proliferation of HepG2 cells in a dose-dependent manner, with little effect on growth of L-02 cells, and when IC50 was measured as 8.45 &mgr;mol/L and 191.55 &mgr;mol/L respectively, the potency of ADFMChR to HepG2 cells, was found to be similar to 5-fluorouracil (5-FU, IC50 was 9.27 &mgr;mol/L). The selective index of ADFMChR cytotoxicity to HepG2 cells was 22.67 (191.55/8.45), higher than 5-FU (SI was 7.05 (65.37/9.27). FCM with PI staining demonstrated that the apoptosis rates of HepG2 cells treated with 3.0, 10.0 and 30.0 &mgr;mol/L ADFMChR for 48 h were 5.79%, 9.29% and 37.8%, respectively, and were significantly higher when treated with 30.0 &mgr;mol/L ADFMChR than when treated with 30.0 &mgr;mol/L ChR (16.0%) (P < 0.05) and were similar to those obtained with 30.0 &mgr;mol/L 5-FU (41.0%). DNA agarose gel electrophoresis showed that treatment of HepG2 cells with 10.0 &mgr;mol/L ADFMChR for 48 h and 72 h resulted in typical DNA ladders which could be reversed by 10.00 &mgr;mol/L GW9662, a blocker of PPARγ. Western blotting analysis revealed that after 24 h of treatment with 3.0, 10.0, 30.0 &mgr;mol/L ADFMChR, PPARγ and Bax protein expression in HepG2 cells increased but Bcl-2 and NF-κB expression decreased; however, pre-incubation with 10.0 &mgr;mol/L GW9662 could efficiently antagonize and weaken the regulatory effect of 3.0, 30.0 &mgr;mol/L ADFMChR on PPARγ and NF-κB protein expression in HepG2 cells.
CONCLUSION: ADFMChR induces apoptosis of HepG2 cell lines by activating PPARγ, inhibiting protein expression of Bcl-2 and NF-κB, and increasing Bax expression.
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Han S, Sun X, Ritzenthaler JD, Roman J. Fish oil inhibits human lung carcinoma cell growth by suppressing integrin-linked kinase. Mol Cancer Res 2009; 7:108-17. [PMID: 19147542 DOI: 10.1158/1541-7786.mcr-08-0384] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We previously showed that synthetic peroxisome proliferator-activated receptor gamma (PPARgamma) ligands inhibit non-small cell lung carcinoma (NSCLC) cell growth through multiple signaling pathways. Here, we show that dietary compounds, such as fish oil (which contains certain kinds of fatty acids like omega3 and omega6 polyunsaturated fatty acids), also inhibit NSCLC cell growth by affecting PPARgamma and by inhibiting the expression of integrin-linked kinase (ILK). Exogenous expression of ILK overcame, whereas silencing ILK enhanced the inhibitory effect of fish oil on cell growth. The inhibitor of p38 mitogen-activated protein kinase, SB239023, abrogated the inhibitory effect of fish oil on ILK expression, whereas the inhibitor of extracellular signal-regulated kinase, PD98059, had no effect. Transient transfection experiments showed that fish oil reduced ILK promoter activity, and this effect was abolished by AP-2alpha small interfering RNA and SB239023 and by deletion of a specific portion of the ILK gene promoter. Western blot analysis and gel mobility shift assay showed that fish oil significantly induced AP-2alpha protein expression and AP-2 DNA-binding activity in the ILK gene promoter and that this was dependent on PPARgamma activation. Blockade of AP-2alpha abrogated the effect of fish oil on ILK expression and on cell growth, whereas exogenous expression of AP-2alpha enhanced cell growth in the setting of fish oil exposure. Taken together, these findings show that fish oil inhibits ILK expression through activation of PPARgamma-mediated and p38 mitogen-activated protein kinase-mediated induction of AP-2alpha. In turn, this leads to inhibition of NSCLC cell proliferation. This study unveils a novel mechanism by which fish oil inhibits human lung cancer cell growth.
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Affiliation(s)
- Shouwei Han
- Division of Pulmonary, Allergy and Critical Care Medicine, Emory University School of Medicine, Whitehead Bioresearch Building, 615 Michael Street, Suite 205-M, Atlanta, GA 30322, 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: 11] [Impact Index Per Article: 0.7] [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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Involvement of PPARα in the growth inhibitory effect of arachidonic acid on breast cancer cells. Br J Nutr 2008; 100:739-50. [DOI: 10.1017/s0007114508942161] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Epidemiological studies suggest that dietary PUFA may influence breast cancer progression.n-3 PUFA are generally known to exert antitumour effects, whereas reports relative ton-6 PUFA anti-carcinogen effects are controversial. Arachidonic acid (AA; 20 : 4n − 6) and its metabolites have been shown to inhibit the growth of human breast cancer cell lines, even if the downstream mechanisms by which AA may influence carcinogenesis remain unresolved. We explored the molecular basis for AA influence on proliferation, signal transduction and apoptosis in two human breast cancer cell lines, MCF-7 and MDA-MB-231. In both cell lines AA inhibited cell growth in a dose-dependent manner, even if MDA-MB-231 was somewhat more growth-inhibited than MCF-7. AA decreased extracellular signal-regulated protein kinase 1/2 phosphorylation level, and positively modulated PPARγ and PPARα expression, with only a slight effect against PPARβ/δ. In addition, AA increased Bak (an apoptosis-regulating protein) expression and reduced procaspase-3 and -9 levels only in MDA-MB-231 cells, thus indicating that the growth inhibitory effect can be correlated with apoptosis induction. In both cell lines the use of a specific antagonist made it possible to establish a relationship between AA growth inhibitory effect and PPARα involvement. AA decreases cell proliferation most likely by inducing apoptosis in MDA-MB-231 cells, while in the MCF-7 cell line the growth inhibitory activity can be attributed to the inhibition of the signal transduction pathway involved in cell proliferation. In both cases, the results here presented suggest PPARα as a possible contributor to the growth inhibitory effect of AA.
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Hoetzel A, Dolinay T, Vallbracht S, Zhang Y, Kim HP, Ifedigbo E, Alber S, Kaynar AM, Schmidt R, Ryter SW, Choi AMK. Carbon monoxide protects against ventilator-induced lung injury via PPAR-gamma and inhibition of Egr-1. Am J Respir Crit Care Med 2008; 177:1223-32. [PMID: 18356564 PMCID: PMC2408440 DOI: 10.1164/rccm.200708-1265oc] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2007] [Accepted: 03/17/2008] [Indexed: 12/31/2022] Open
Abstract
RATIONALE Ventilator-induced lung injury (VILI) leads to an unacceptably high mortality. In this regard, the antiinflammatory properties of inhaled carbon monoxide (CO) may provide a therapeutic option. OBJECTIVES This study explores the mechanisms of CO-dependent protection in a mouse model of VILI. METHODS Mice were ventilated (12 ml/kg, 1-8 h) with air in the absence or presence of CO (250 ppm). Airway pressures, blood pressure, and blood gases were monitored. Lung tissue was analyzed for inflammation, injury, and gene expression. Bronchoalveolar lavage fluid was analyzed for protein, cell and neutrophil counts, and cytokines. MEASUREMENTS AND MAIN RESULTS Mechanical ventilation caused significant lung injury reflected by increases in protein concentration, total cell and neutrophil counts in the bronchoalveolar lavage fluid, as well as the induction of heme oxygenase-1 and heat shock protein-70 in lung tissue. In contrast, CO application prevented lung injury during ventilation, inhibited stress-gene up-regulation, and decreased lung neutrophil infiltration. These effects were preceded by the inhibition of ventilation-induced cytokine and chemokine production. Furthermore, CO prevented the early ventilation-dependent up-regulation of early growth response-1 (Egr-1). Egr-1-deficient mice did not sustain lung injury after ventilation, relative to wild-type mice, suggesting that Egr-1 acts as a key proinflammatory regulator in VILI. Moreover, inhibition of peroxysome proliferator-activated receptor (PPAR)-gamma, an antiinflammatory nuclear regulator, by GW9662 abolished the protective effects of CO. CONCLUSIONS Mechanical ventilation causes profound lung injury and inflammatory responses. CO treatment conferred protection in this model dependent on PPAR-gamma and inhibition of Egr-1.
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Affiliation(s)
- Alexander Hoetzel
- Department of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
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Chen D, Jin G, Wang Y, Wang H, Liu H, Liu Y, Fan W, Ma H, Miao R, Hu Z, Sun W, Qian J, Jin L, Wei Q, Shen H, Huang W, Lu D. Genetic variants in peroxisome proliferator-activated receptor-γ gene are associated with risk of lung cancer in a Chinese population. Carcinogenesis 2008; 29:342-50. [DOI: 10.1093/carcin/bgm285] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Wang J, Lv X, Shi J, Hu X. Ceramide induces apoptosis via a peroxisome proliferator-activated receptor gamma-dependent pathway. Apoptosis 2007; 11:2043-52. [PMID: 17036198 DOI: 10.1007/s10495-006-0191-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Both of ceramide and PPARgamma ligand can trigger cancer cell apoptosis. We here show that C2-ceramide can modulate PPARgamma expression level and its transcriptional activity and results in apoptosis in HT29 cells. Administration of PPARgamma specific antagonist GW9662 partially prevents HT29 cells from apoptosis. Furthermore, MAP kinase pathway provided a potential modulation mechanism for PPARgamma pathway related with ceramide. Our results are the first to demonstrate that C2-ceramide induces apoptosis via a PPARgamma-dependent pathway.
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Affiliation(s)
- Jing Wang
- College of Life Science, Peking University, Beijing, China.
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Papageorgiou E, Pitulis N, Msaouel P, Lembessis P, Koutsilieris M. The non-genomic crosstalk between PPAR-gamma ligands and ERK1/2 in cancer cell lines. Expert Opin Ther Targets 2007; 11:1071-85. [PMID: 17665979 DOI: 10.1517/14728222.11.8.1071] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Peroxisome proliferator activated receptors (PPARs) are members of the nuclear receptor superfamily acting as transcription factors. PPAR-gamma, one of the three PPAR subtypes, is expressed in many malignant and non-malignant cells and tissues. PPAR-gamma ligands influence cancer biology via both genomic as well as non-genomic events. The non-genomic action of PPAR-gamma ligands, including the activation of MAPK signaling pathways, is under intense investigation. In the presence of PPAR-gamma ligands, a rapid phosphorylation of ERK1/2 is observed in many cancer cell lines. Activated ERK1/2 elicits rapid, non-genomic cellular effects and can directly repress PPAR-gamma transcriptional activity by phosphorylation. This paper reviews the interrelation of PPAR-gamma ligands and activated ERK1/2, in relation to their antineoplastic actions in cancer cell lines, which may offer the potential for improved anticancer therapies.
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Affiliation(s)
- Efstathia Papageorgiou
- National & Kapodistrian University of Athens, Department of Experimental Physiology, Medical School, Goudi-Athens, Greece
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Ai XH, Zheng X, Tang XQ, Sun L, Zhang YQ, Qin Y, Liu HQ, Xia H, Cao JG. Induction of apoptosis of human gastric carcinoma SGC-7901 cell line by 5, 7-dihydroxy-8-nitrochrysin in vitro. World J Gastroenterol 2007; 13:3824-8. [PMID: 17657836 PMCID: PMC4611214 DOI: 10.3748/wjg.v13.i28.3824] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of 5, 7-dihydroxy-8-nitrochrysin (NOChR) on apoptosis of human gastric carcinoma SGC-7901 cell line.
METHODS: SGC-7901 cells were cultured in vitro and the inhibitory effect of NOChR on proliferation of SGC-7901 cells was measured by using an MTT assay. NOChR-induced apoptosis rate of SGC-7901 cells was detected using flow cytometry (FCM) with PI staining. DNA ladder bands were observed by DNA agarose gel electrophoresis. The influence of NOChR on the proxisome proliferator-activated receptor-γ (PPARγ), Bcl-2 and Bax protein expression of SGC-7901 cells was analyzed by Western blot.
RESULTS: MTT assay showed that NOChR markedly inhibited proliferation of SGC-7901 cells in a dose-dependent manner, and when IC50 was 4.14 μmol/L, the potency of NOChR was 10 times than that of lead compound, chrysin (ChR, IC50 was 40.56 μmol/L), and was similar to 5-fluorouracil (5-FU, IC50 was 4.51 μmol/L). FCM with propidium iodide (PI) staining demonstrated that the apoptosis rates of SGC-7901 cells treated with 1.25, 5.00 and 20.00 μmol/L NOChR for 48 h were 9.8% ± 0.2%, 36.8% ± 1.9% and 45.5% ± 3.5%, respectively, and were significantly higher when treated with 5.00 and 20.00 μmol/L NOChR than that with 20.00 μmol/L ChR (12.9% ± 1.5%). DNA agarose gel electrophoresis showed that treatment of SGC-7901 cells with 20.00 μmol/L NOChR for 48 h resulted in typical DNA ladder bands of DNA of SGC-7901 cells, which could be eliminated by treating with 10.00 μmol/L GW9662, a blocker of PPARγ. Western blot analysis revealed that after 24 h of treatment with 20.00 μmol/L NOChR, PPARgamma and Bax protein expression of SGC-7901 cells increased but Bcl-2 expression decreased; however, pre-incubation with 10.00 μmol/L GW9662 could efficiently antagonize and weaken the regulatory effect of 20.00 μmol/L NOChR on Bax and Bcl-2 protein expression of SGC-7901 cells.
CONCLUSION: NOChR induces apoptosis of SGC-7901 cell lines by activating PPARγ and decreasing ratio of Bcl-2 to Bax.
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Affiliation(s)
- Xiao-Hong Ai
- Department of Oncology, First Affiliated Hospital, Nahua University, Hengyang 421001, Hunan Province, China
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Hazra S, Dubinett SM. Ciglitazone mediates COX-2 dependent suppression of PGE2 in human non-small cell lung cancer cells. Prostaglandins Leukot Essent Fatty Acids 2007; 77:51-8. [PMID: 17697767 PMCID: PMC2045645 DOI: 10.1016/j.plefa.2007.05.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Revised: 05/13/2007] [Accepted: 05/17/2007] [Indexed: 11/20/2022]
Abstract
BACKGROUND Cyclooxygenase-2 (COX-2) over-expression and subsequent prostaglandin E2 (PGE2) production are frequently associated with human non-small-cell lung cancer (NSCLC) and are involved in tumor proliferation, invasion, angiogenesis, and resistance to apoptosis. Here, we report that ciglitazone downregulates PGE2 in NSCLC cells. METHODS PGE2 ELISA assay and COX-2 ELISA assay were performed for measuring PGE2 and COX-2, respectively, in NSCLC. The mRNA level of COX-2 was measured by semi-quantitative RT-PCR. The transient transfection experiments were performed to measure COX-2 and peroxisome proliferator-response element (PPRE) promoter activity in NSCLC. Western blots were unitized to measure PGE synthase (PGES) and 15-hydroxyprostaglandin dehydrogenase (15-PGDH) protein expression. RESULTS COX-2 ELISA assays suggested that ciglitazone-dependent inhibition of PGE2 occurs through the suppression of COX-2. Ciglitazone treatment suppressed COX-2 mRNA expression and COX-2 promoter activity while upregulating PPRE promoter activity. Ciglitazone did not modify the expression of enzymes downstream of COX-2 including PGES and 15-PGDH. Utilization of a dominant-negative PPARgamma showed that the suppression of COX-2 and PGE2 by ciglitazone is mediated via non-PPAR pathways. CONCLUSION Taken together, our findings suggest that ciglitazone is a negative modulator of COX-2/PGE2 in NSCLC.
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Affiliation(s)
- Saswati Hazra
- Lung Cancer Research Program of the Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
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Hong KM, Belperio JA, Keane MP, Burdick MD, Strieter RM. Differentiation of human circulating fibrocytes as mediated by transforming growth factor-beta and peroxisome proliferator-activated receptor gamma. J Biol Chem 2007; 282:22910-20. [PMID: 17556364 DOI: 10.1074/jbc.m703597200] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fibrocytes are a distinct population of fibroblast-like progenitor cells in peripheral blood that have recently been shown to possess plasticity to differentiate along mesenchymal lineages, including commitment to myofibroblast and adipocyte cells. Here, we demonstrated that transforming growth factor (TGF) beta1 drives fibrocyte-to-myofibroblast differentiation through activating Smad2/3 and SAPK/JNK MAPK pathways, which in turn stimulates alpha-smooth muscle actin expression. We determined that SAPK/JNK signaling acts in a positive feedback loop to modulate Smad2/3 nuclear availability and Smad2/3-dependent transcription. Conversely, fibrocyte-to-adipocyte differentiation is driven by the peroxisome proliferator-activated receptor (PPAR) gamma agonist troglitazone, which is associated with cytoplasmic lipid accumulation and induction of aP2. Treatment with troglitazone also disrupted TGF beta 1-activated SAPK/JNK signaling, leading to decreased Smad2/3 transactivation activity and alpha-smooth muscle actin expression. Interestingly, TGF beta 1 was demonstrated to have reciprocal inhibition on fibrocyte differentiation to adipocytes. By activating SAPK/JNK signaling, which is normally suppressed during adipogenesis, PPARgamma-dependent transactivation activity and induction of aP2 expression were disrupted. Taken together, within the context of the local microenvironmental niche, the delicate balance of PPARgamma and TGF beta 1 activation drives the selection of an adipocyte or myofibroblast differentiation pathway through SAPK/JNK signaling.
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Affiliation(s)
- Kurt M Hong
- Center for Human Nutrition and the Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California 90024, USA
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Kim KY, Ahn JH, Cheon HG. Apoptotic action of peroxisome proliferator-activated receptor-gamma activation in human non small-cell lung cancer is mediated via proline oxidase-induced reactive oxygen species formation. Mol Pharmacol 2007; 72:674-85. [PMID: 17535976 DOI: 10.1124/mol.107.035584] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Peroxisome proliferator-activated receptor (PPAR)-gamma ligands have been shown to inhibit human lung cancers by inducing apoptosis and differentiation. In the present study, we elucidated the apoptotic mechanism of PPARgamma activation in human lung cancers by using a novel PPARgamma agonist, 1-(trans-methylimino-N-oxy)-6-(2-morpholinoethoxy)-3-phenyl-(1H-indene-2-carboxylic acid ethyl ester (KR-62980), and rosiglitazone. PPARgamma activation selectively inhibited cell viability of non-small-cell lung cancer with little effect on small-cell lung cancer and normal lung cells. The cell death induced by PPARgamma activation presented apoptotic features of oligonucleosomal DNA fragmentation in A549 human non-small-cell lung cancer cell line. Reactive oxygen species (ROS) production was accompanied by increased expression of proline oxidase (POX), a redox enzyme expressed in mitochondria, upon incubation with the agonists. POX RNA interference treatment blocked PPARgamma-induced ROS formation and cytotoxicity, suggesting that POX plays a functional role in apoptosis through ROS formation. The apoptotic effects by the agonists were antagonized by bisphenol A diglycidyl ether, a PPARgamma antagonist, and by knockdown of PPARgamma expression, indicating the involvement of PPARgamma in these actions. The results of the present study suggest that PPARgamma activation induces apoptotic cell death in non-small-cell lung carcinoma mainly through ROS formation via POX induction.
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Affiliation(s)
- Ki Young Kim
- Center for Metabolic Syndrome Therapeutics, Drug Discovery Division, Korea Research Institute of Chemical Technology, Daejeon, Korea
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Kim S, Hong I, Hwang JS, Choi JK, Rho HS, Kim DH, Chang I, Lee SH, Lee MO, Hwang JS. Phytosphingosine stimulates the differentiation of human keratinocytes and inhibits TPA-induced inflammatory epidermal hyperplasia in hairless mouse skin. Mol Med 2006; 12:17-24. [PMID: 16838068 PMCID: PMC1514555 DOI: 10.2119/2006-00001.kim] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Accepted: 03/21/2006] [Indexed: 01/22/2023] Open
Abstract
The binding of sphingoid bases to peroxisome proliferator-activated receptor (PPAR) has been detected in a solid-phase binding assay. However, sphingoid base-induced changes in PPAR transactivation activity have not been examined. In this report, we show by reporter gene analyses that phytosphingosine (PS), a natural sphingoid base, activates the transcriptional activity of PPARs in the immortalized human keratinocyte, HaCaT. Real-time PCR analyses showed that the mRNA level of PPARgamma was increased after PS treatment in HaCaT cells in a dose- and time-dependent manner. Because PPARs play important roles in skin barrier homeostasis by regulating epidermal cell growth, terminal differentiation, and inflammatory response, we examined the effect of PS on normal human epidermal keratinocytes (NHEKs) and mouse skin. PS increased the production of cornified envelope in NHEKs by approximately 1.8-fold compared with controls. Epidermal differentiation marker proteins such as involucrin, loricrin, and keratin1 were also increased in PS-treated NHEKs, by ELISA or Western blotting analysis. A [(3)H]thymidine incorporation assay showed that PS inhibited DNA synthesis in NHEKs to 20% compared with controls. The antiproliferative and anti-inflammatory effects of PS were examined in a mouse model of irritant contact dermatitis produced by topical application of 12-O-tetradecanoylphorbol-13-acetate (TPA). PS blocked epidermal thickening and edema and the infiltration of inflammatory cells into the dermis in the skin of TPA-treated hairless mice. The anti-inflammatory effects of PS were confirmed by the observation that PS blocked the TPA-induced generation of prostaglandin E(2) in peripheral mononuclear leukocytes. Taken together, our results provide an insight into the multiple regulatory roles of PS in epidermal homeostasis, and furthermore point to the potential use of PS as a therapeutic agent in the treatment of inflammatory and proliferative cutaneous diseases.
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Affiliation(s)
- Sujong Kim
- Skin Research Institute, AmorePacific Corporation R&D Center, Kyounggi, South
Korea
- Address correspondence and reprint requests to Dr. Sujong Kim; Jae Sung
Hwang, Skin Research Institute, Amore-Pacific Corporation R&D Center, 314-1 Bora-ri, Kiheung-eup, Yongin-si, Kyounggi-do 449-729, Korea. Phone: +82-31-280-5962; fax: +82-31-282-6063; e-mail: (Sujong Kim); (Jae Sung Hwang)
| | - Il Hong
- College of Pharmacy and Bio-MAX Institute, Seoul National University, Seoul, South
Korea
| | - Jung Sun Hwang
- Skin Research Institute, AmorePacific Corporation R&D Center, Kyounggi, South
Korea
| | - Jin Kyu Choi
- Skin Research Institute, AmorePacific Corporation R&D Center, Kyounggi, South
Korea
| | - Ho Sik Rho
- Skin Research Institute, AmorePacific Corporation R&D Center, Kyounggi, South
Korea
| | - Duck Hee Kim
- Skin Research Institute, AmorePacific Corporation R&D Center, Kyounggi, South
Korea
| | - Ihseop Chang
- Skin Research Institute, AmorePacific Corporation R&D Center, Kyounggi, South
Korea
| | - Seung Hun Lee
- Department of Dermatology, Yonsei University College of Medicine, Seoul, South
Korea
| | - Mi-Ock Lee
- College of Pharmacy and Bio-MAX Institute, Seoul National University, Seoul, South
Korea
| | - Jae Sung Hwang
- Skin Research Institute, AmorePacific Corporation R&D Center, Kyounggi, South
Korea
- Address correspondence and reprint requests to Dr. Sujong Kim; Jae Sung
Hwang, Skin Research Institute, Amore-Pacific Corporation R&D Center, 314-1 Bora-ri, Kiheung-eup, Yongin-si, Kyounggi-do 449-729, Korea. Phone: +82-31-280-5962; fax: +82-31-282-6063; e-mail: (Sujong Kim); (Jae Sung Hwang)
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Kim HJ, Woo IS, Kang ES, Eun SY, Kim GH, Ham SA, Kim HJ, Lee JH, Chang KC, Kim JH, Lee HT, Seo HG. Phorbol ester potentiates the growth inhibitory effects of troglitazone via up-regulation of PPARgamma in A549 cells. Biochem Biophys Res Commun 2006; 349:660-7. [PMID: 16945329 DOI: 10.1016/j.bbrc.2006.08.085] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Accepted: 08/16/2006] [Indexed: 01/09/2023]
Abstract
The activation of peroxisome proliferator-activated receptor gamma (PPARgamma) has been shown to induce growth arrest and differentiation of various cancer cells. In the current study, we investigated the effect of 12-O-tetradecanoylphorbol-13-acetate (TPA) on the expression of PPARgamma and proliferation of A549 cells. TPA elicited a dose- and time-dependent increase in PPARgamma mRNA and protein levels. PPARgamma expression in response to TPA was attenuated by pretreatment with bisindolylmaleimide I, N-acetyl-L-cysteine (NAC) and PD98059. TPA-induced protein kinase C (PKC) activation was linked to the generation of reactive oxygen species (ROS), both of which were indispensable for PPARgamma expression in A549 cells. Pretreatment with bisindolylmaleimide I or NAC blocked TPA-induced phosphorylation of extracellular signal-regulated kinase (ERK), suggesting that ERK-mediated signaling is also involved in the induction of PPARgamma. Furthermore, the growth inhibitory effect of troglitazone was significantly potentiated by prolonged incubation with TPA and was attenuated in the presence of GW9662, a specific inhibitor of PPARgamma. These effects were associated with an induction of cell cycle arrest at G0/G1 phase, which was accompanied by the induction of p21Waf1/Cip1 expression and decreased cyclin D1 expression. Taken together, these observations indicate that TPA synergizes with PPARgamma ligand to inhibit cell growth through up-regulation of PPARgamma expression.
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Affiliation(s)
- Hyo Jung Kim
- Department of Pharmacology, Gyeongsang Institute of Health Science, College of Medicine, Gyeongsang National University, Jinju 660-751, Republic of Korea
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Abstract
Peroxisome proliferator-activated receptors gamma (PPAR?) is a transcriptional factor belonging to the ligand-activated nuclear receptor superfamily. PPAR? is highly expressed in adipose tissue and has a dominant regulatory role in adipocyte differentiation. In humans, PPAR? is expressed in multiple tissues such as the breast, colon, lung, ovary, and placenta. In addition to adipogenic and anti-inflammatory effects, PPAR? activation has been shown to be anti-proliferative by virtue of its differentiation-promoting effect, suggesting that activation of PPAR? may be useful in slowing or arresting the proliferation of de-differentiated tumor cells. A number of PPAR? ligands, such as natural prostaglandins and synthetic anti-diabetic thiazolidinediones (TZDs), have been identified. The discovery of PPAR? agonists has enabled the elucidation of the mechanisms involved in the multiple effects of PPAR? on the inhibition of tumor cell growth. The importance of this transcription factor in physiology and pathophysiology has stimulated much research in this field. This review describes structural features of PPAR?, mechanisms of PPAR? gene transcription, and recent developments in the discovery of its biological functions on growth inhibition of lung tumors. Prospects for future research leading to new therapies for lung cancer are also discussed.
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Affiliation(s)
- Ming-Yue Li
- Department of Surgery, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
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Li M, Lee TW, Yim APC, Mok TSK, Chen GG. Apoptosis induced by troglitazone is both peroxisome proliferator-activated receptor-γ- and ERK-dependent in human non-small lung cancer cells. J Cell Physiol 2006; 209:428-38. [PMID: 16883598 DOI: 10.1002/jcp.20738] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The role of the peroxisome proliferator-activated receptor-gamma (PPARgamma) in cell differentiation, cell-cycle arrest, and apoptosis has attracted increasing attention. We have recently demonstrated that PPARgamma ligands-troglitazone (TGZ) induced apoptosis in lung cancer cells. In this report, we further studied the role of ERK1/2 in lung cancer cells treated by TGZ. The result demonstrated that TGZ induced PPARgamma and ERK1/2 accumulation in the nucleus, in which the co-localization of both proteins was found. The activation of ERK1/2 resulted in apoptosis via a mitochondrial pathway. Both PPARgamma siRNA and U0126, a specific inhibitor of ERK1/2, were able to block these effects of TGZ, suggesting that apoptosis induced by TGZ was PPARgamma and ERK1/2 dependent. Inhibition of ERK1/2 by U0126 also led to a significant decrease in the level of PPARgamma, indicating a positive cross-talk between PPARgamma and ERK1/2 or an auto-regulatory feedback mechanism to amplify the effect of ERK1/2 on cell growth arrest and apoptosis. In addition to ERK1/2, TGZ also activated Akt. Interestingly, inhibition of ERK1/2 prevented the activation of Akt whereas the suppression of Akt had no effect on ERK1/2, suggesting that Akt was not necessary for TGZ-PPARgamma-ERK pathway. However, the inhibition of Akt promoted the release of cytochrome c, suggesting the activation of Akt may have a negative effect on apoptosis induced by TGZ. In conclusion, our study has demonstrated that TGZ, a synthetic PPARgamma ligand, induced apoptosis in NCI-H23 lung cancer cells via a mitochondrial pathway and this pathway was PPARgamma and ERK1/2 dependent.
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Affiliation(s)
- Mingyue Li
- Department of Surgery, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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Peraza MA, Burdick AD, Marin HE, Gonzalez FJ, Peters JM. The Toxicology of Ligands for Peroxisome Proliferator-Activated Receptors (PPAR). Toxicol Sci 2005; 90:269-95. [PMID: 16322072 DOI: 10.1093/toxsci/kfj062] [Citation(s) in RCA: 200] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand activated transcription factors that modulate target gene expression in response to endogenous and exogenous ligands. Ligands for the PPARs have been widely developed for the treatment of various diseases including dyslipidemias and diabetes. While targeting selective receptor activation is an established therapeutic approach for the treatment of various diseases, a variety of toxicities are known to occur in response to ligand administration. Whether PPAR ligands produce toxicity via a receptor-dependent and/or off-target-mediated mechanism(s) is not always known. Extrapolation of data derived from animal models and/or in vitro models, to humans, is also questionable. The different toxicities and mechanisms associated with administration of ligands for the three PPARs will be discussed, and important data gaps that could increase our current understanding of how PPAR ligands lead to toxicity will be highlighted.
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Affiliation(s)
- Marjorie A Peraza
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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