ABSTRACT
COX-2 overexpression and subsequent PGE(2) production are frequently associated with non-small cell lung cancer and are implicated in tumor-mediated angiogenesis. Here, we report for the first time that IL-20 downregulates COX-2 and PGE(2) in human bronchial epithelial and endothelial cells. Flow cytometry analysis suggests that IL-20-dependent inhibition of COX-2/PGE(2) occurs through the IL-22R1/IL-20R2 dimers. In addition, we report that IL-20 exerts anti-angiogenic effects, inhibiting experimental angiogenesis. IL-20-mediated inhibition of PMA-induced angiogenesis occurs through the COX-2 regulatory pathway. Altogether our findings revealed that IL-20 is a negative modulator of COX-2/PGE(2) and inhibits angiogenesis.
Subject(s)
Angiogenesis Inhibitors/administration & dosage , Carcinoma, Non-Small-Cell Lung/metabolism , Dinoprostone/metabolism , Interleukins/administration & dosage , Neovascularization, Pathologic/metabolism , Prostaglandin-Endoperoxide Synthases/metabolism , Respiratory Mucosa/metabolism , Cell Line, Tumor , Cells, Cultured , Cyclooxygenase 2 , Cytokines/administration & dosage , Dose-Response Relationship, Drug , Gene Expression Regulation/drug effects , Humans , Membrane Proteins , Neovascularization, Pathologic/pathology , Respiratory Mucosa/drug effectsABSTRACT
Elevated tumor cyclooxygenase 2 (COX-2) expression is associated with increased angiogenesis, tumor invasion, and promotion of tumor cell resistance to apoptosis. In our previous studies using non-small cell lung cancer (NSCLC) cell lines constitutively expressing COX-2 cDNA in sense and antisense orientations, we demonstrated that constitutive overexpression of COX-2 leads to stabilization of the inhibitor of apoptosis protein survivin resulting in the elevated apoptosis resistance of COX-2-overexpressing cells. Genetic or pharmacologic suppression of COX-2 activity increased proteasomal degradation of survivin and cellular response to apoptosis induction. Our data show that expression of survivin in non-small cell lung cancer cells can be significantly down-regulated by RNA interference. Whereas COX-2-overexpressing NSCLC cells have significantly higher apoptosis resistance than the parental cells, inhibition of survivin expression by small interfering RNA decreases apoptosis resistance to the level of the parental non-small cell lung cancer. We conclude that COX-2-dependent expression of survivin is critical for apoptosis resistance in non-small cell lung cancer.
Subject(s)
Apoptosis/physiology , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Isoenzymes/metabolism , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Microtubule-Associated Proteins/antagonists & inhibitors , Microtubule-Associated Proteins/biosynthesis , Prostaglandin-Endoperoxide Synthases/metabolism , Carcinoma, Non-Small-Cell Lung/enzymology , Carcinoma, Non-Small-Cell Lung/genetics , Cell Line, Tumor , Cyclooxygenase 2 , Humans , Inhibitor of Apoptosis Proteins , Lung Neoplasms/enzymology , Lung Neoplasms/genetics , Membrane Proteins , Microtubule-Associated Proteins/genetics , Neoplasm Proteins , RNA Interference , RNA, Small Interfering/genetics , RNA, Small Interfering/pharmacology , Survivin , TransfectionABSTRACT
Constitutive overexpression of cyclooxygenase-2 (COX-2) occurs frequently in several different malignancies, including lung, colon, breast, and prostate cancer. Clinical studies have established elevated serum insulin-like growth factor (IGF-I) content and IGF-I:IGF-binding protein 3 (IGFBP-3) ratio as risk factors for these same malignancies. Therefore, we sought to determine the link between COX-2 expression and the IGF axis in COX-2 gene-modified human non-small-cell lung cancer (NSCLC) cells. Overexpression of COX-2 in NSCLC cells enhanced the antiapoptotic and mitogenic effects of IGF-I and IGF-II, facilitated the autophosphorylation of the type 1 IGF receptor, increased class IA phosphatidylinositol 3'-kinase activity, and decreased expression of IGFBP-3. Thus, these findings show that COX-2 augments the stimulatory arm of the IGF axis.
Subject(s)
Carcinoma, Non-Small-Cell Lung/enzymology , Insulin-Like Growth Factor II/physiology , Insulin-Like Growth Factor I/physiology , Isoenzymes/physiology , Lung Neoplasms/enzymology , Prostaglandin-Endoperoxide Synthases/physiology , Receptor, IGF Type 1/metabolism , Apoptosis/physiology , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Celecoxib , Cell Division/physiology , Cell Line, Tumor , Cell Survival/physiology , Cyclooxygenase 2 , DNA, Antisense/genetics , Down-Regulation/drug effects , Humans , Insulin-Like Growth Factor Binding Protein 3/biosynthesis , Insulin-Like Growth Factor I/pharmacology , Insulin-Like Growth Factor II/pharmacology , Isoenzymes/antagonists & inhibitors , Isoenzymes/biosynthesis , Isoenzymes/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Membrane Proteins , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors , Phosphorylation , Prostaglandin-Endoperoxide Synthases/biosynthesis , Prostaglandin-Endoperoxide Synthases/genetics , Pyrazoles , Signal Transduction/physiology , Sulfonamides/pharmacologyABSTRACT
Lung cancer is the leading cause of cancer death in the United States. Although the low 5-year survival rate (under 15%) has changed minimally in the last 25 years, new agents and combinations of agents that target tumor proliferation, invasion, and survival may lead to improvement in patient outcomes. There is evidence that cyclooxygenase-2 (COX-2) is overexpressed in lung cancer and promotes tumor proliferation, invasion, angiogenesis, and resistance to apoptosis. COX-2 inhibitors have been found to inhibit tumor growth in animal models and have demonstrated responses when combined with conventional therapy in phase II clinical trials. Further understanding of the mechanisms involved in COX-2-mediated tumorigenesis and its interaction with other molecules in lung cancer may lead to improved therapeutic strategies for this disease. In addition, delineation of how COX-2-dependent genes modulate the malignant phenotype will provide novel insights in lung cancer pathogenesis.
Subject(s)
Isoenzymes/physiology , Lung Neoplasms/etiology , Prostaglandin-Endoperoxide Synthases/physiology , Antigen-Presenting Cells/physiology , Apoptosis , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Cyclooxygenase Inhibitors/therapeutic use , Cytokines/physiology , ErbB Receptors/antagonists & inhibitors , Humans , Lung Neoplasms/immunology , Lung Neoplasms/prevention & control , Membrane Proteins , Neovascularization, Pathologic/etiologySubject(s)
Carcinoma, Non-Small-Cell Lung/metabolism , Dinoprostone/metabolism , Isoenzymes/metabolism , Lung Neoplasms/metabolism , Microtubule-Associated Proteins/metabolism , Neoplasm Proteins/metabolism , Prostaglandin-Endoperoxide Synthases/metabolism , Animals , Antisense Elements (Genetics) , Cell Line, Tumor , Cyclooxygenase 2 , Gene Expression , Humans , Inhibitor of Apoptosis Proteins , Membrane Proteins , Mice , Mice, SCID , SurvivinABSTRACT
Elevated tumor cyclooxygenase (COX)-2 activity plays a multifaceted role in non-small cell lung cancer (NSCLC). To elucidate the role of COX-2 in the in vitro and in vivo expression of two known NSCLC angiogenic peptides, CXC ligand (CXCL) 8 and CXCL5, we studied two COX-2 gene-modified NSCLC cell lines, A549 and H157. COX-2 overexpression enhanced the in vitro expression of both CXCL8 and CXCL5. In contrast, specific COX-2 inhibition decreased the production of both peptides as well as nuclear translocation of nuclear factor kappaB. In a severe combined immunodeficient mouse model of human NSCLC, the enhanced tumor growth of COX-2-overexpressing tumors was inhibited by neutralizing anti-CXCL5 and anti-CXCL8 antisera. We conclude that COX-2 contributes to the progression of NSCLC tumorigenesis by enhancing the expression of angiogenic chemokines CXCL8 and CXCL5.
Subject(s)
Carcinoma, Non-Small-Cell Lung/blood supply , Chemokines, CXC/analysis , Intercellular Signaling Peptides and Proteins/analysis , Isoenzymes/physiology , Lung Neoplasms/blood supply , Prostaglandin-Endoperoxide Synthases/physiology , Active Transport, Cell Nucleus , Animals , Carcinoma, Non-Small-Cell Lung/chemistry , Carcinoma, Non-Small-Cell Lung/drug therapy , Cell Line, Tumor , Chemokine CXCL5 , Cyclooxygenase 2 , Dinoprostone/physiology , Humans , Isoenzymes/antagonists & inhibitors , Lung Neoplasms/chemistry , Lung Neoplasms/drug therapy , Membrane Proteins , Mice , Mice, SCID , NF-kappa B/metabolism , Neovascularization, Pathologic/etiologyABSTRACT
Elevated tumor cyclooxygenase 2 (COX-2) expression is associated with increased angiogenesis, tumor invasion and promotion of tumor cell resistance to apoptosis. The mechanism(s) by which COX-2 exerts its cytoprotective effects are not completely understood but may be due to an imbalance of pro- and anti-apoptotic gene expression. To analyze COX-2-dependent gene expression and apoptosis, we created cell lines constitutively expressing COX-2 cDNA in sense and antisense orientations. Whereas COX-2 sense cells have significantly heightened resistance to radiation and drug-induced apoptosis, COX-2 antisense cells are highly sensitive to apoptosis induction. We found that the expression of the anti-apoptotic protein survivin correlated positively with COX-2 expression. A COX-2-dependent modulation of survivin ubiquitination led to its stabilization in COX-2 overexpressing cells, and this effect was replicated by exogenous PGE2 treatment of parental tumor cells. In contrast to previous studies in other cell types, in nonsmall cell lung cancer cells survivin was expressed in a cell cycle-independent manner. When established in SCID mice in vivo, COX-2 antisense-derived tumors had significantly decreased survivin levels while COX-2 sense-derived tumors demonstrated elevated levels compared with controls. In accord with these findings, survivin and COX-2 were frequently upregulated and co-expressed in human lung cancers in situ.
Subject(s)
Carcinoma, Non-Small-Cell Lung/enzymology , Isoenzymes/metabolism , Lung Neoplasms/enzymology , Microtubule-Associated Proteins/metabolism , Prostaglandin-Endoperoxide Synthases/metabolism , Animals , Antisense Elements (Genetics) , Apoptosis , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Cycle , Cell Line, Tumor , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Cyclooxygenase Inhibitors/pharmacology , Dinoprostone/pharmacology , Humans , Inhibitor of Apoptosis Proteins , Isoenzymes/antagonists & inhibitors , Isoenzymes/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Membrane Proteins , Mice , Neoplasm Proteins , Prostaglandin-Endoperoxide Synthases/genetics , Survivin , Ubiquitins/metabolism , Up-RegulationSubject(s)
Isoenzymes/physiology , Lung Neoplasms/etiology , Prostaglandin-Endoperoxide Synthases/physiology , Animals , Antigen-Presenting Cells/physiology , Apoptosis , Carcinoma, Non-Small-Cell Lung/prevention & control , Clinical Trials, Phase III as Topic , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Cyclooxygenase Inhibitors/therapeutic use , Cytokines/biosynthesis , Humans , Isoenzymes/antagonists & inhibitors , Lung Neoplasms/immunology , Lung Neoplasms/prevention & control , Membrane Proteins , Neoplasm Invasiveness , Neovascularization, Pathologic/etiologyABSTRACT
T lymphocyte survival is critical for the development and maintenance of an effective host antitumor immune response; however, the tumor environment can negatively impact T-cell survival. Lymphocytes exposed to tumor supernatants (TSNs) were evaluated for apoptosis after mitogen stimulation. TSN was observed to significantly enhance phorbol 12-myristate 13-acetate/ionomycin- and anti-CD3-stimulated lymphocyte apoptosis. Enhanced lymphocyte apoptosis was associated with an impairment of nuclear factor kappa B nuclear translocation and diminished I kappa B alpha degradation. In lymphocytes stimulated after exposure to TSNs, cytoplasmic I kappa B alpha persisted as a result of alterations in I kappa B kinase (IKK) activity. Accordingly, although there were no apparent differences in IKK component concentrations, lymphocytes preexposed to TSNs exhibited markedly reduced IKK activity. We conclude that non-small cell lung cancer-derived soluble factors promote apoptosis in activated lymphocytes by an IKK-dependent pathway.
Subject(s)
Apoptosis/immunology , Carcinoma, Non-Small-Cell Lung/immunology , Lung Neoplasms/immunology , Protein Serine-Threonine Kinases/immunology , T-Lymphocytes/immunology , Adenocarcinoma/enzymology , Adenocarcinoma/immunology , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , CD3 Complex/immunology , Carcinoma, Non-Small-Cell Lung/enzymology , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Humans , I-kappa B Kinase , I-kappa B Proteins/immunology , I-kappa B Proteins/metabolism , Ionomycin/pharmacology , Jurkat Cells/enzymology , Jurkat Cells/immunology , Jurkat Cells/pathology , Lung Neoplasms/enzymology , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , NF-kappa B/immunology , NF-kappa B/metabolism , Protein Serine-Threonine Kinases/metabolism , T-Lymphocytes/enzymology , T-Lymphocytes/pathology , Tetradecanoylphorbol Acetate/pharmacologySubject(s)
Carcinoma, Lewis Lung/enzymology , Carcinoma, Lewis Lung/immunology , Isoenzymes/antagonists & inhibitors , Pyrazoles , Sulfonamides , Animals , Antigen-Presenting Cells/immunology , Blotting, Northern/methods , Blotting, Western/methods , Carcinoma, Lewis Lung/prevention & control , Cyclooxygenase 2 , Cyclooxygenase 2 Inhibitors , Cyclooxygenase Inhibitors/pharmacology , Cyclooxygenase Inhibitors/therapeutic use , Female , Interleukin-10/metabolism , Interleukin-12/metabolism , Isoenzymes/metabolism , Macrophages/immunology , Macrophages/metabolism , Mice , Mice, Inbred C57BL , Prostaglandin-Endoperoxide Synthases/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Transfection , Tumor Cells, CulturedABSTRACT
Tumor cyclooxygenase-2 (COX-2) expression is known to be associated with enhanced tumor invasiveness. In the present study, we evaluated the importance of the COX-2 product prostaglandin E2 (PGE2) and its signaling through the EP4 receptor in mediating non-small cell lung cancer (NSCLC) invasiveness. Genetic inhibition of tumor COX-2 led to diminished matrix metalloproteinase (MMP)-2, CD44, and EP4 receptor expression and invasion. Treatment of NSCLC cells with exogenous 16,16-dimethylprostaglandin E2 significantly increased EP4 receptor, CD44, and MMP-2 expression and matrigel invasion. In contrast, anti-PGE2 decreased EP4 receptor, CD44, and MMP-2 expression in NSCLC cells. EP4 receptor signaling was found to be central to this process, because antisense oligonucleotide-mediated inhibition of tumor cell EP4 receptors significantly decreased CD44 expression. In addition, agents that increased intracellular cAMP, as is typical of EP4 receptor signaling, markedly increased CD44 expression. Moreover, MMP-2-AS treatment decreased PGE2-mediated CD44 expression, and CD44-AS treatment decreased MMP-2 expression. Thus, PGE2-mediated effects through EP4 required the parallel induction of both CD44 and MMP-2 expression because genetic inhibition of either MMP-2 or CD44 expression effectively blocked PGE2-mediated invasion in NSCLC. These findings indicate that PGE2 regulates COX-2-dependent, CD44- and MMP-2-mediated invasion in NSCLC in an autocrine/paracrine manner via EP receptor signaling. Thus, blocking PGE2 production or activity by genetic or pharmacological interventions may prove to be beneficial in chemoprevention or treatment of NSCLC.