1.The effects of cromakalim on the mediator releases from guinea pig lung mast cell activated by specific antigen-antibody reactions.
Jai Youl RO ; Young Nae YIM ; Kyung Hwan KIM
Yonsei Medical Journal 1996;37(5):325-338
The inhibitory effect of cromakalim on the mediator release from mast cells caused by antigenantibody reactions was in controversy with the specific antigen used. However, it has recently been observed that cromakalim inhibits the release of mediators from superfused tracheal and parenchymal strips or lung mast cells after passive sensitization with the IgG1 antibody. An attempt, therefore, was made to determine the inhibitory mechanisms of cromakalim on the release of mediators such as histamine and leukotriene released by the activation of enzymes during mast cell activation. Guinea pig lung mast cells were purified through enzyme digestion, rough percoll and continuous percoll density gradients. The purified mast cells were prelabeled with [3H]palmitic acid. PLD activity was assessed more directly by the production of labeled phosphatidylethanol by PLD-mediated transphosphatidylation in the presence of ethanol. In the cells labelled with [3H]myristic acid, [3H] DAG production was measured. The methyltransferase activity was assessed by measuring the incorporation of [3H]methyl moiety into phospholipids in sensitized mast cells labelled with L-[3H] methylmethionine. cAMP level was measured by radioimmunoassay. Cromakalim resulted in a decrease in the amount of histamine and leukotrienes releases by 30% in the ovalumin-induced mast cell. Cromakalim had little effect on phospholipase D activity enhanced by the activated mast cell. Cromakalim inhibited the initial increase of diacylglycerol production during mast cell activations. Cromakalim inhibited the phospholipid methylation increased in the activated mast cell. These results show that cromakalim decreases histamine release by inhibiting the initial increase of 1,2-diacylglycerol during the mast cell activation, which is mediated via the phosphatidylinositide-phospholipase C system rather than the phosphatidylcholine-phospholipase D system. Furthermore, cromakalim reduces phosphatidylcholine production by inhibiting the methyltransferase, which decreases the conversion of phosphatidylcholine into arachidonic acid and inhibits the production of leukotrienes.
Adenylate Cyclase/metabolism
;
Animal
;
*Antigen-Antibody Reactions
;
Benzopyrans/*pharmacology
;
Cromakalim
;
Diglycerides/biosynthesis
;
Female
;
Guinea Pigs
;
Histamine Release/*drug effects
;
Leukotrienes/*secretion
;
Lung/drug effects/secretion
;
Mast Cells/*drug effects/secretion
;
Methylation
;
Phospholipase D/metabolism
;
Phospholipids/metabolism
;
Potassium Channels/*drug effects
;
Pyrroles/*pharmacology
;
Support, Non-U.S. Gov't
2.The effects of cromakalim on the mediator releases from guinea pig lung mast cell activated by specific antigen-antibody reactions.
Jai Youl RO ; Young Nae YIM ; Kyung Hwan KIM
Yonsei Medical Journal 1996;37(5):325-338
The inhibitory effect of cromakalim on the mediator release from mast cells caused by antigenantibody reactions was in controversy with the specific antigen used. However, it has recently been observed that cromakalim inhibits the release of mediators from superfused tracheal and parenchymal strips or lung mast cells after passive sensitization with the IgG1 antibody. An attempt, therefore, was made to determine the inhibitory mechanisms of cromakalim on the release of mediators such as histamine and leukotriene released by the activation of enzymes during mast cell activation. Guinea pig lung mast cells were purified through enzyme digestion, rough percoll and continuous percoll density gradients. The purified mast cells were prelabeled with [3H]palmitic acid. PLD activity was assessed more directly by the production of labeled phosphatidylethanol by PLD-mediated transphosphatidylation in the presence of ethanol. In the cells labelled with [3H]myristic acid, [3H] DAG production was measured. The methyltransferase activity was assessed by measuring the incorporation of [3H]methyl moiety into phospholipids in sensitized mast cells labelled with L-[3H] methylmethionine. cAMP level was measured by radioimmunoassay. Cromakalim resulted in a decrease in the amount of histamine and leukotrienes releases by 30% in the ovalumin-induced mast cell. Cromakalim had little effect on phospholipase D activity enhanced by the activated mast cell. Cromakalim inhibited the initial increase of diacylglycerol production during mast cell activations. Cromakalim inhibited the phospholipid methylation increased in the activated mast cell. These results show that cromakalim decreases histamine release by inhibiting the initial increase of 1,2-diacylglycerol during the mast cell activation, which is mediated via the phosphatidylinositide-phospholipase C system rather than the phosphatidylcholine-phospholipase D system. Furthermore, cromakalim reduces phosphatidylcholine production by inhibiting the methyltransferase, which decreases the conversion of phosphatidylcholine into arachidonic acid and inhibits the production of leukotrienes.
Adenylate Cyclase/metabolism
;
Animal
;
*Antigen-Antibody Reactions
;
Benzopyrans/*pharmacology
;
Cromakalim
;
Diglycerides/biosynthesis
;
Female
;
Guinea Pigs
;
Histamine Release/*drug effects
;
Leukotrienes/*secretion
;
Lung/drug effects/secretion
;
Mast Cells/*drug effects/secretion
;
Methylation
;
Phospholipase D/metabolism
;
Phospholipids/metabolism
;
Potassium Channels/*drug effects
;
Pyrroles/*pharmacology
;
Support, Non-U.S. Gov't
3.Toll like receptor 2 mediates bleomycin-induced acute lung injury, inflammation and fibrosis in mice.
Han-zhi LIU ; Hong-zhen YANG ; Su MI ; Bing CUI ; Fang HUA ; Zhuo-wei HU
Acta Pharmaceutica Sinica 2010;45(8):976-986
Anti-cancer drug bleomycin (BLM) can cause acute lung injury (ALI) which often results in pulmonary fibrosis due to a failure of resolving acute inflammatory response. The aim of this study is to investigate whether toll-like receptor (TLR) 2 mediates BLM-induced ALI, inflammation and fibrosis. BLM-induced dendritic cells (DCs) maturation was analyzed by flow cytometry and cytokine secretion was detected by the ELISA method. The expression and activity of p38 and ERK MAPK were determined with Western blotting. The roles of TLR2 in ALI, inflammation and fibrosis were investigated in C57BL/6 mice administered intratracheally with BLM. The results demonstrated that BLM-administered mice had higher expression of TLR2 (P<0.001) and its signaling molecules. Blocking TLR2 significantly inhibited the maturation of DCs and reversed BLM-stimulated secretion of cytokines in DCs, such as IL-6 (P<0.001), IL-17 (P<0.05) and IL-23 (P<0.05). TLR2 inhibition attenuated BLM-induced increase of inflammatory cells in bronchoalveolar lavage fluid (BALF), and reversed the immunosuppressive microenvironment by enhancing TH1 response (P<0.05) and inhibiting TH2 (P<0.001), Treg (P<0.01) and TH17 (P<0.01) responses. Importantly, blocking TLR2 in vivo significantly protected BLM-administered mice from pulmonary injury, inflammation and fibrosis and subsequently increased BLM-induced animal survival (from 50% to 92%). Therefore, TLR2 is a novel potential target for ALI and pulmonary fibrosis.
Acute Lung Injury
;
chemically induced
;
metabolism
;
pathology
;
Animals
;
Bleomycin
;
toxicity
;
Bronchoalveolar Lavage Fluid
;
Cells, Cultured
;
Cytokines
;
secretion
;
Dendritic Cells
;
cytology
;
metabolism
;
Inflammation
;
chemically induced
;
metabolism
;
pathology
;
Interleukin-17
;
secretion
;
Interleukin-23
;
secretion
;
Interleukin-6
;
secretion
;
Lung
;
metabolism
;
MAP Kinase Signaling System
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Pulmonary Fibrosis
;
chemically induced
;
metabolism
;
pathology
;
T-Lymphocytes, Regulatory
;
drug effects
;
Th1 Cells
;
drug effects
;
Th2 Cells
;
drug effects
;
Toll-Like Receptor 2
;
metabolism
;
physiology
4.Naringenin may block RSV-induced mucous hypersecretion in A549 cell via JNK/AP-1 signaling pathway.
Shanshan MENG ; Yanling WU ; Xiaoguang HU ; Hailin ZHANG ; Changchong LI
Chinese Journal of Pediatrics 2015;53(3):182-186
OBJECTIVENaringenin has been reported to attenuate Mucin (MUC) 5AC secretion in many pathological models. Many stimuli activate MUC5AC expression through JNK/AP-1 signaling pathways. We hypothesized that naringenin may have inhibitory effects on mucous hypersecretion by modulating MUC5AC production and inhibiting JNK/AP-1 signaling pathways.
METHODThe cell model of mucous hypersecretion was made by human lung adenocarcinoma epithelial (A549) cells stimulated by RSV. A549 cells were subcultured and then randomly divided into 7 groups, which were designated as group C (cell control group), groups R1-3 (cells were infected with RSV at the multiplication of infection (MOI) of 0. 5, 1. 0, 5. 0), groups N1-2 (cells infected with viruses in presence of Nar 30 - 100 mol/L), groups N3-4 (uninfected cells treated with Nar 30 - 100 µmol/L), group D (DMSO), group S (cells infected with viruses in presence of SP600125). After incubating for 24 hrs, the expression of MUC5AC at mRNA and protein level in the groups were determined by real-time quantitative PCR and enzyme-linked immunosorbent assay (ELISA). The protein expression changes of JNK, p-JNK and AP-1 were measured by Western blotting.
RESULTThe expressions of MUC5AC protein and mRNA in all RSV infected groups were significantly higher than that in group C in a dose-dependent manner (all P <0. 05). Nar of 30 and 100 µmol/L significantly and dose-dependently decreased RSV-induced secretion of MUC5AC protein in cell supernatant and expression of MUC5AC mRNA (P <0. 05). The relative content of p-JNK, AP-l in R2 groups were 3. 31 ± 0. 34 and 1. 94 ± 0. 05. Theyfrweremtgnificanty increased as compared with group C (both 1. 00 ± 0. 00) (all P <0. 05). The levels of p-JNK in N2 and S groups were 2. 10 ± 0. 20. 27 and 1.±97 ± 0. 16. The levels of AP-1 in N2 and S groups were 1. 40 ± 0. 03, 1. 36 ± 0. 05. Nar and SP600125 led to a largest decrease in levels of p-JNK and AP-1 when compared with group R2 (P <0. 05). The MUC5AC protein in group R2 was (48. 19 ± 0. 47) µg/L. The protein expression of MUC5AC in group R2 was significantly higher than that in group C [(36. 67 ± 1. 50) g/L] with a statistically significant difference (P <0. 05). The protein expression of MUC5AC in groups N2 and S were(43. 17 ± 1. 06) µg/L, (44.±02 ± 0. 99) µg/L, Nar and SP600125 remarkably inhibited RSV-induced secretion of MUC5AC in supernatant of A549 cells (P < 0. 05).
CONCLUSIONSNaringenin might be able to block RSV-induced mucous
Adenocarcinoma ; Blotting, Western ; Cell Line, Tumor ; Enzyme-Linked Immunosorbent Assay ; Epithelial Cells ; Flavanones ; pharmacology ; Humans ; Lung Neoplasms ; Mucin 5AC ; secretion ; Mucus ; secretion ; Random Allocation ; Signal Transduction ; Transcription Factor AP-1 ; drug effects
5.Effect of dexamethasone on expression of AGR2 protein in asthmatic mice.
Min ZHOU ; Hui-long CHEN ; Sheng CHENG ; Li MEI ; Hui-lan ZHANG ; Min XIE ; Wei-ning XIONG ; Yong-jian XU
Journal of Huazhong University of Science and Technology (Medical Sciences) 2013;33(1):33-36
This study examined the expression of the anterior gradient-2 (AGR2) protein and Muc5ac protein in the lung tissues of asthmatic mice and the effect of dexamethasone, with an attempt to explore the role of AGR2 in the over-secretion of mucus in the airway. Eighteen BALB/c mice were divided into asthma group, control group and dexamethasone group. In dexamethasone group, dexamethasone was intraperitoneally administered. Expression of AGR2 protein and Muc5ac protein in the murine lung tissues was immunohistochemically detected. IL-13 level was determined in the bronchoalveolar lavage fluid (BALF) by ELISA. The results exhibited that the expression of AGR2 protein in asthma group (0.522±0.041) was significantly higher than that in normal controls (0.361±0.047) (P<0.01) and bore a positive linear relationship to the expression of Muc5ac protein (r=0.873, P<0.05) and IL-13 level (r=0.828, P<0.05). Expression of AGR2 protein in the dexamethasone group (0.456±0.049) was significantly lower than that in the asthma group. It was concluded that: (1) the expression of AGR2 protein was significantly higher in asthmatic mice as compared with their normal counterparts; (2) the expression was obviously related to the expression of Muc5ac protein and IL-13; (3) dexamethasone could down-regulate the expression of AGR2 protein. Our findings suggested that AGR2 might be involved in the over-secretion of mucus in the airway in asthma.
Animals
;
Anti-Inflammatory Agents
;
pharmacology
;
Asthma
;
drug therapy
;
metabolism
;
Dexamethasone
;
pharmacology
;
Female
;
Interleukin-13
;
metabolism
;
Lung
;
drug effects
;
metabolism
;
Mice
;
Mice, Inbred BALB C
;
Mucin 5AC
;
metabolism
;
Mucoproteins
;
metabolism
;
Mucus
;
secretion
;
Treatment Outcome
6.IL-4 and IL-5 Secretions Predominate in the Airways of Wistar Rats Exposed to Toluene Diisocyanate Vapor.
Kouame KOUADIO ; Kui Cheng ZHENG ; Abdoulaye Abba TOURE ; Mireille DOSSO ; Hidemi TODORIKI
Journal of Preventive Medicine and Public Health 2014;47(1):57-63
OBJECTIVES: We established a Wistar rat model of asthma caused by toluene diisocyanate (TDI) exposure, and investigated the relationship between TDI exposure concentrations and respiratory hypersensitivity, airway inflammation, and cytokine secretions in animals, to better understand the mechanism of TDI induced occupational asthma. METHODS: Wistar rats were exposed to two different concentrations of TDI vapor four hours a day for five consecutive days. Bronchoalveolar lavage (BAL) was performed, and differential leucocytes from the BAL fluid were analyzed. Lung histopathological examination was carried out to investigate the inflammatory status in the airways. Production of cytokines interleukin (IL)-4 and IL-5 productions in the BAL fluid in vivo was determined with enzyme-linked immunosorbent assay kits. RESULTS: The TDI-exposed rats exhibited greater airway hypersensitivity symptoms than the control rats. The BAL differential cell count and lung histopathological examination demonstrated that inflammation reactions were present in both the central and peripheral airways, characterized with marked infiltration of eosinophils in the TDI-exposed rats. The cytokine assay showed that IL-4 and IL-5 were predominantly produced in the BAL fluid in vivo. CONCLUSIONS: These findings imply that TDI exposure concentrations may greatly affect the occurrence and extent of inflammatory events and that Th2 type cytokines may play an important role in the immunopathogenesis of TDI-induced occupational respiratory hypersensitivity.
Animals
;
Bronchoalveolar Lavage Fluid/chemistry/cytology
;
Enzyme-Linked Immunosorbent Assay
;
Eosinophils/cytology/immunology
;
Female
;
Gases/chemistry
;
Hypersensitivity/pathology
;
Interleukin-4/*analysis
;
Interleukin-5/*analysis
;
Lung/*drug effects/pathology/secretion
;
Rats
;
Rats, Wistar
;
Toluene 2,4-Diisocyanate/*toxicity
7.Role of extracellular signal-regulated kinase 1/2 in cigarette smoke-induced mucus hypersecretion in a rat model.
Jun XIAO ; Ke WANG ; Yu-Lin FENG ; Xue-Rong CHEN ; Dan XU ; Ming-Ke ZHANG
Chinese Medical Journal 2011;124(20):3327-3333
BACKGROUNDAirway mucus hypersecretion is an important pathophysiological feature of chronic obstructive pulmonary disease, which is closely associated with cigarette smoking. However, the signal transduction pathway from the cell surface to the nucleus through which cigarette smoke causes upregulation of mucin gene expression is not well known. This study was designed to investigate the role of extracellular signal-regulated Kinase 1/2 (ERK 1/2) in airway mucus hypersecretion induced by cigarette smoke in rats.
METHODSA rat model of airway mucus hypersecretion was induced by exposure to cigarette smoke for 4 weeks.Rats exposed to inhalation of cigarette smoke or normal saline were given an intraperitoneal injection of U0126, a specific MEK1 kinase inhibitor, at doses of 0.25 mg/kg, 0.5 mg/kg and 1 mg/kg for 14 days. Expression of MUC5AC mRNA and protein, ERK 1/2 and phosphorylated-ERK 1/2 (p-ERK 1/2) were detected by RT-PCR, immunohistochemistry and Western blotting.
RESULTSCigarette smoke significantly increased airway goblet cells metaplasia, induced the overexpression of MUC5AC mRNA and protein in bronchial epithelia, and increased the ratio of p-ERK 1/2 and ERK 1/2. U0126 significantly attentuated the expression of MUC5AC mRNA and protein induced by cigarette smoke (P < 0.05). Moreover, there was a significant positive correlation between the ratio of p-ERK1/2 to ERK1/2 and the expression of MUC5AC mRNA and protein (P < 0.05).
CONCLUSIONSInhibition of ERK 1/2 by U0126 decreased the ratio of p-ERK 1/2 to ERK 1/2 and expression of MUC5AC mRNA and protein. ERK 1/2 may play an essential role in cigarette smoke-induced mucus hypersecretion in vivo.
Animals ; Blotting, Western ; Bronchi ; cytology ; metabolism ; Goblet Cells ; drug effects ; metabolism ; Immunohistochemistry ; Lung ; drug effects ; metabolism ; Mitogen-Activated Protein Kinase 1 ; genetics ; metabolism ; Mitogen-Activated Protein Kinase 3 ; genetics ; metabolism ; Mucin 5AC ; genetics ; metabolism ; Phosphorylation ; drug effects ; Rats ; Respiratory Mucosa ; secretion ; Reverse Transcriptase Polymerase Chain Reaction ; Smoking ; adverse effects
8.Combined effects of neonatal Bacillus Calmette-Guerin vaccination and respiratory syncytial infection on experimental asthma in mice.
Rui LI ; En-mei LIU ; Xi-qiang YANG ; Li-jia WANG
Chinese Journal of Pediatrics 2006;44(6):420-424
OBJECTIVENeonatal Bacillus Calmette-Guerin (BCG) vaccination could decrease asthma prevalence in human according to "hygiene hypothesis". The authors proposed a hypothesis that effect of BCG vaccination on inhibiting asthma in human might be reversed by respiratory virus infection. The objective of this study was to observe combined effects of neonatal BCG vaccination and respiratory syncytial virus (RSV) infection on experimental asthma in mice.
METHODSNeonatal BALB/c mice were divided into five groups. Control and ovalbumin (OVA) groups were mock-vaccinated at birth and mock-infected at 3 weeks of age. BCG + OVA group was BCG-vaccinated and mock-infected. RSV + OVA group was mock-vaccinated and RSV-infected. BCG + RSV + OVA group was BCG-vaccinated and RSV-infected. Except for control group, all the other groups underwent ovalbumin (OVA) sensitization and challenge. Airway responsiveness to inhaled methacholine was measured and bronchoalveolar lavage (BAL) was performed after the last challege. Cells in BAL fluid (BALF) were counted. Cytokines in BALF and serum OVA-specific IgE were detected by ELISA and inflammatory characteristics of lungs was scored by staining with hematoxylin and eosin.
RESULTS(1) The numbers of total white cells, lymphocytes, monocytes, neutrophils, and eosinophils in the BALF from all OVA-sensitized/challenged groups were significantly greater than those in control (P < 0.01), and BCG + OVA group had significantly lower total white cells, lymphocytes and eosinophils as compared with other OVA-sensitized/challenged groups (P < 0.05 or 0.01). (2) All OVA-sensitized/challenged groups had significantly lower IFNgamma (P < 0.05) and higher IL-4 (P < 0.05) level in BALF as compared with control, but there was no significant difference among all OVA sensitized/challenged groups. There was no significant difference in IL-10 level between all experimental groups. (3) All OVA-sensitized/challenged groups showed significantly higher serum OVA-specific IgE titers than control (P < 0.05 or 0.01), but no significant difference was found among all OVA sensitized/challenged groups. (4) RSV + OVA and BCG + RSV + OVA groups displayed the highest airway resistance and subsequently in order as follows: OVA group, BCG + OVA group and control group in severity of airway hyperreactivity (AHR), but no significant difference was found between RSV + OVA and BCG + RSV + OVA groups. (5) Histological score of peribronchiolitis, perivasculitis, alveolitis, and peribronchial eosinophilia in all OVA-sensitized/challenged groups was significantly higher than that in control. BCG + OVA group had significantly milder peribronchiolitis and peribronchial eosinophilia than the other OVA-sensitized/challenged groups (P < 0.05) and significantly milder alveolitis than OVA and BCG + RSV + OVA groups (P < 0.05).
CONCLUSIONNeonatal BCG vaccination decreased asthmatic inflammation and AHR and RSV infection could reverse anti-asthma effect of neonatal BCG vaccination in OVA-sensitized/challenged mouse model.
Animals ; Animals, Newborn ; Asthma ; immunology ; prevention & control ; BCG Vaccine ; administration & dosage ; immunology ; pharmacology ; Bronchoalveolar Lavage Fluid ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Eosinophils ; drug effects ; immunology ; secretion ; Immunoglobulin E ; analysis ; immunology ; Interferon-gamma ; analysis ; immunology ; Interleukin-10 ; analysis ; immunology ; Interleukin-4 ; analysis ; immunology ; Leukocytes ; drug effects ; immunology ; secretion ; Lung ; drug effects ; immunology ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; administration & dosage ; immunology ; toxicity ; Respiratory Syncytial Virus Infections ; immunology ; Respiratory Syncytial Viruses ; immunology ; pathogenicity ; Treatment Outcome
9.Adeno-associated virus-mediated CD40 ligand transfer into human lung cancer cells.
Jian-qing WU ; Wei-hong ZHAO ; Kai-sheng YIN ; Yun-lin CHENG
Chinese Journal of Oncology 2007;29(4):253-257
OBJECTIVETo investigate the transduction efficiency of serotype 1, 2, 5, 6, 7, 8, 9, 10 recombinant adeno-associated viruses (rAAV) in human lung cancer cell line A549 cells and compare the transduction efficiency of conventional AAV vectors with that of self-complementary AAV (scAAV) vectors. Furthermore, the capacity of A549 cells expressing transgenic CD40L to stimulate dendritic cells (DCs) was evaluated.
METHODSLung cancer A549 cells were infected with 1 x 10(4) particules per cell of AAV encoding the green fluorescent protein (GFP) or human CD40L driven by CMV promotor, and transgene expression was analyzed by flow cytometry and fluorescence microscopy. Stimulation of isolated human dendritic cells by CD40L-expressing tumor cells was quantified by measuring secreted interleukin-12 with immunoassay.
RESULTSSerotype AAV2/5 transduced A549 cells much more efficiently than serotypes AAV2/1, AAV2/2, AAV2/6, AAV2/7, AAV2/8, AAV2/9 and AAV2/10. The transduction efficiency of scAAV2/5 was significantly higher than that of conventional AAV2/5. Furthermore, pre-treatment with carboplatin substantially increased AAV-mediated transgene expression. The scAAV2/5 vectors encoding human CD40L was used to generate CD40L. A549 cells transduce by these vectors were co-cultured with immature human DCs. As a consequence, interleukin-12 was released and measured in the culture supernatant. Specificity of immunostimulatory effect of CD40L was confirmed by blocking with a monoclonal antibody binding to human CD40L.
CONCLUSIONscAAV2/5 transduce lung adenocarcinoma A549 cell efficiently, and co-administration of chemotherapeutic agent carboplatin further enhances its transduction efficiency. It is confirmed that lung cancer cells infected with a CD40L-encoding scAAV2/5 construct can activate human DCs to secrete interleukin-12. Our findings provided a basis for future immunotherapeutic approaches including intratumoral transfer of stimulating factors.
Antineoplastic Agents ; pharmacology ; Blotting, Western ; CD40 Ligand ; genetics ; metabolism ; physiology ; Carboplatin ; pharmacology ; Cell Line ; Cell Line, Tumor ; Coculture Techniques ; Dendritic Cells ; cytology ; secretion ; Dependovirus ; classification ; genetics ; Flow Cytometry ; Gene Expression ; drug effects ; Genetic Vectors ; Green Fluorescent Proteins ; genetics ; metabolism ; Humans ; Immunoassay ; methods ; Interleukin-12 ; secretion ; Lung Neoplasms ; genetics ; metabolism ; pathology ; Microscopy, Fluorescence ; Recombinant Fusion Proteins ; genetics ; metabolism ; Serotyping ; Transfection
10.Tumor microenvironment elicits primary resistance to afatinib through HGF secretion.
Xiao-hong KANG ; Li-fang WANG ; Fei CAO ; Fang-tian FAN ; Zhen-ye XU
Chinese Journal of Oncology 2013;35(10):732-736
OBJECTIVETo observe the effects of hepatocyte growth factor (HGF) derived from tumor microenvironment and/or afatinib on the growth of human lung adenocarcinoma H1975 cells and explore the potential mechanisms by which HGF induces primary resistance to afatinib.
METHODSThe effects of HGF, TGF-α and afatinib on the growth of H1975 cells were evaluated by MTT assay. The HGF concentrations of normal human fetal lung fibroblasts MRC-5 cells and human lung adenocarcinoma H1975 cells co-cultured or separately cultured were determined by ELISA assay. Western blot was used to detect the expressions of EGFR and Met signal pathway-related proteins and epithelial-mesenchymal transition (EMT) markers in H1975 cells treated with HGF and/or afatinib.
RESULTSThe MTT assay showed that H1975 cells were hyposensitive to afatinib in the presence of HGF. The ELISA assay showed that HGF production by H1975 cells was less than 0.1 ng/2.0×10(6) cells, but HGF production by MRC-5 cells was (151.37 ± 2.07)ng/2.0×10(6) cells incubated for 48 h. When H1975 cells and MRC-5 cells were co-cultured for 72 h, the concentration of HGF in the culture supernatant was (61.13 ± 16.21)ng/ml. In the presence of HGF, the expression of p-Met, p-Akt and p-ERK proteins in the H1975 cells was markedly up-regulated. afatinib inhibited p-EGFR, but did not affect the expression of p-Met, p-Akt and p-ERK proteins. In the presence of afatinib, HGF up-regulated the expression of vimentin and down-regulated the expression of E-cadherin.
CONCLUSIONSHGF secreted by stromal cells in the tumor micro-environment may confer resistance to afatinib in H1975 cells by activation of the Met/PI3K/Akt and Met/MAPK/ERK signaling pathways, and is involved in the epithelial-mesenchymal transition process.
Adenocarcinoma ; metabolism ; pathology ; Antineoplastic Agents ; pharmacology ; Cadherins ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cells, Cultured ; Coculture Techniques ; Drug Resistance, Neoplasm ; Epithelial-Mesenchymal Transition ; Fibroblasts ; cytology ; metabolism ; Hepatocyte Growth Factor ; pharmacology ; secretion ; Humans ; Lung ; cytology ; Lung Neoplasms ; metabolism ; pathology ; MAP Kinase Signaling System ; drug effects ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Proto-Oncogene Proteins c-met ; metabolism ; Quinazolines ; pharmacology ; Receptor, Epidermal Growth Factor ; metabolism ; Signal Transduction ; drug effects ; Transforming Growth Factor alpha ; pharmacology ; Tumor Microenvironment ; Vimentin ; metabolism