Xing Lihua

Influence of ciglitazone on A549 cells growthin vitro andin vivo and mechanism

SummaryThe effect and mechanism of the ciglitazone on lung cancer cells A549 growthin vitro andin vivo were studied. Various concentrations of ciglitazone were added to the cultured A549 line, and the proliferation and differentiation of A549 cells were examined by MTT and cytometry analysis. A549 cells (1×106/mouse) were inoculated subcutaneously into 20 nude mice, which were randomly divided into two groups: the control group, the ciglitazone treated group. The weights of subcutaneous tumors were measured. The expression of cyclin D1 and P21 in the lung was detected by immohistochemistry and Western blot respectively. The results showed that the proliferation of A549 was inhibited significantly by ciglitazone in a dose- and time-dependent manner. There were more cells arrested in G1/G0 phase and the expression of PPARγ was markedly up-regulated in ciglitazone-treated group. Direct injection of ciglitazone into A549-induced tumors could suppress tumor growth in nude mice and the growth inhibitory rate was 36%. The expression of cyclin D1 was decreased and P21 increased significantly in ciglitazone-treated group as compared with control group. It was concluded that ciglitazone could inhibit A549 proliferation dose-dependently and time-dependently and induce differentiation, which might be related to the modulation of cell cycle interfered by PPARγ.

The expression of hypoxia inducible factor 1-alpha in lung cancer and its correlation with P53 and VEGF

To investigate the expression of hypoxia inducible factor 1-alpha (HIF-1alpha) and its correlation with P53 and vascular endothelial growth factor (VEGF), immunohistochemical technique was employed to detect the protein expressions of HIF-1alpha, P53 and VEGF in specimens from 57 patients with lung cancer. The results indicated that the total positive proportion of HIF-1alpha expression was 63% and the HIF-1alpha expression was more frequent in bronchiole-alveolar carcinoma (86%) than in other lung cancer. There was a strong association of HIF-1alpha with VEGF and P53 protein expressions. It is concluded that HIF-1alpha overexpression is a common event in lung cancer, which may be related to the up-regulation of the angiogenic factor VEGF and oncogene mutant P53 protein.SummaryTo investigate the expression of hypoxia inducible factor 1-alpha (HIF-1α) and its correlation with P53 and vascular endothelial growth factor (VEGF), immunohistochemical technique was employed to detect the protein expressions of HIF-1α, P53 and VEGF in specimens from 57 patients with lung cancer. The results indicated that the total positive proportion of HIF-1α expresion was 63% and the HIF-1α expression was more frequent in bronchiole-alveolar carcinoma (86%) than in other lung cancer. There was a strong association of HIF-1α with VEGF and P53 protein expressions. It is concluded that HIF-1α overexpression is a common event in lung cancer, which may be related to the up-regulation of the angiogenic factor VEGF and oncogene mutant P53 protein.

Expression of Angiopoietin-2 gene in non-small cell lung cancer

SummaryTo study the expression of Angiopoietin 2 (Ang-2) gene and its relationship with clinical pathological characteristics of non-small cell lung cancer (NSCLC), expression of the Ang-2 mRNA was evaluated by employing reverse transcription polymerase chain reaction (RT-PCR) in cancerous tissues and paired adjacent noncancerous tissues from 52 patients. The expression of Ang-2 gene was detected in a significantly greater proportion of cancerous tissues (80.8%) than paired adjacent noncancerous tissues (53.8%,P<0.01). No significant relationship was found between Ang-2 gene expression and patients’ age, sex, histology of tumors, differentiation and TNM stages (P>0.05). It is concluded that the up-regulation of Ang-2 gene may play a role in the pathway of NSCLC carcinogenesis and Ang-2 may be used as a potential therapeutic agent for lung cancer.

The Effects of Nimesulide Combined with Cisplatin on Lung Cancer

SummaryTo study the effects of cyclooxygenase 2 selective inhibitor Nimesulide (NIM) combined with Cisplatin (DDP) on human lung cancer and the possible mechanisms, the proliferation and appoptosis of human lung cancer cell line A549 were evaluated by MTT reduction assay and flow cytometry respectively. The inhibitory effect on neoplasiain vivo was tested on nude mice subcutaneously implanted tumor. Our results showed that NIM and DDP could inhibit A549 cell proliferation in a concentration-dependent pattern; this action was enhanced when NIM (25 μmol/L) was given in combination with DDP and they worked in a synergistic or additive pattern as DDP concentration ≥1 μg/ml. NIM and DDP could induce A549 cells apoptosis and the action was augmented when used in combination (P<0.01). NIM and DDP could inhibit the growth of subcutaneously implanted tumors on nude mice (P<0.05,P<0.01) and the inhibitory rate of NIM combined with DDP was significantly higher than that of NIM or DDP group (P<0.01,P<0.01). It is concluded that combined use of NIM and DDP has significant synergistic antitumor effects on lung cancer cell line A549 and in animalsin vivo. The synergy may be achieved by growth inhibition and apoptosis induction.

Expression and Significance of Cyclooxygenase 2 Gene in Lung Cancer

SummaryTo study the expression of cyclooxygenase 2 (COX-2) gene and its relationship with clinicopathological characteristics of lung cancer, expression of the COX-2 mRNA was evaluated by reverse transcription polymerase chain reaction (RT-PCR) in cancerous tissues and paired adjacent non-cancerous tissues from 56 patients and benign lesions from 12 patients. Our results showed that expression of COX-2 gene was detected in a significantly greater proportion of cancerous tissues (60.7%) than adjacent noncancerous tissues (10.7%,P<0.01) and benign lesions (3/12,P<0.05). Expression of COX-2 gene was higher in adenocarcinoma than in squamous carcinoma (P<0.01). There was no significant relationship between COX-2 gene expression and patients age, sex, histological type of tumors, differentiation degree and TNM stages (P>0.05). The up-regulation of COX-2 gene in lung cancer tissues especially in adenocarcinoma suggested that COX-2 may play a role in the lung carcinogenesis and COX-2 gene may serve as a potential therapeutic target in lung cancer.

The effect of interleukin-18 on airway inflammation in asthmatic murine models and its mechanisms.

In order to investigate the effect of interleukin-18 (IL-18) on airway inflammation in asthmatic murine models and its mechanisms, BALB/C mice were randomly divided into three groups (n=10 in each group): group A (control group); group B (asthmatic model group); group C (IL-18-treated group). The asthmatic model was established in groups B and C by respiratory syncytial virus (RSV) killed by ultraviolet. Saline solution (0.1 mL) and IL-18 (0.1 mL, 1 μg) were intraperitoneally injected respectively in groups B and C at 7 time points (day 1, 2, 7, 8, 9, 21, 22). The number of eosinophils (EOS) and plasmacytes in the airway was observed. The levels of interferon gamma (IFN-γ) in bronchoalveolar lavage fluid (BALF) were measured by ELISA. The results showed that symptoms of asthma in group C were more severe than in groups A and B. In group A, there were no EOS and plasmacytes in the airway submucosa. The number of EOS [15±3 (average cell counts per microscopic visual field, the same below)] and plasmacytes (10±2) in group B were increased significantly. However, the number of EOS and plasmacytes in group C (6±2 and 2±1, respectively) was decreased significantly as compared with group B (both P<0.05). The levels of IFN-γ in groups A, B and C were 31±3, 40±5 and 63±5 pg/mL respectively, and those in group C were significantly higher than in groups A and B (both P<0.05). It was suggested that the mechanism by which IL-18 inhibited the airway inflammation in asthmatic mice might be contributed to the fact that IL-18 could induce the induction of IFN-γ.

Effects of glucocorticoid on IL-13-induced Muc5ac expression in airways of mice

SummaryTo study the effects of glucocorticoid on the IL 13-induced Muc5ac expression in airways of mice, and investigate its role in mucus secretion of airways, 24 pathogen-free BALB/c mice were randomly divided into 3 groups, IL-13 group received an nasal instillation of 100 μg of recombinant murine IL-13 solution on days 1, 3 and 5. In dexamethasone group, dexamethasone (0. 5 mg/kg) was administered intraperitoneally 24 h before and 1 h before the first instillation of IL-13 and on 4 consecutive days (day 0 to day 5, 6 consecutive days in total), while control group was not treated with IL-13 or dexamethasone. Bronchoalveolar lavage fluid (BALF) was collected and eosinophils were counted, and expression of Muc5ac mRNA and protein in lungs were detected by reverse transcription-polymerase chain reaction (RT-PCR) technology and immunohistochemical assay respectively. Our results showed that the number of mice, with positve Muc5ac protein expression expression of Muc5ac mRNA and cosinophils in BALF after IL-13 treatment were all significantly higher than that of control group (allP<0.01). Despite cosinophils reduced (P<0.01), the number of mice with positive Muc5ac protein expression, expression of Muc5ac mRNA after dexamethasone treatment didn’t decreas significantly as compared with that of IL-13 group. It is concluded that IL-13 can up-regulate the expression of Muc5ac mRNA and protein, which may play a pivotal role in the mucus overproduction of airways. Dexamethasone can suppress IL-13-induced cosinophilic infiltration in lung but cant inhibit the mucus overproduction.