Zhang Hui-Lan

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.

Hypoxia-Inducible Factor-1alpha Suppressing Apoptosis and Increasing Tolerance of Lung Cancer Cells to Chemotherapy

In order to construct plasmid of hypoxia-inducible factor-lalpha (HIF-1α), and transfect into human lung cancer cells A549, the change in sensitivity of lung cancer cells A549 to chemotherapy was observed. HIF-1α mRNA structure region was amplified by RT-PCR and inserted into plasmid pcDNA3. The expression plasmid pcDNA3/HIF-1α was transfected into A549 with Lipofec-tAMINE™2000. The expression of HIF-1α protein was detected by Western blot. After A549 cells were transfected with HIF-1α prior to addition of 5-Fu, the growth activity was measured by growth curve, apoptosis was detected by flow cytometry at 48 h, and the levels of caspase3 and MDR-1 were determined by Western blot. The results showed that the constructed expression plasmid was analyzed with restriction enzymes and gel electrophoresis. Two DNA lanes at 2.55 kb and 5.4 kb respectively were found, which were consistent with that expected. The growth rate in 5-Fu group was significantly inhibited, and the apoptosis index and caspase3 activity were increased significantly as compared with control group. After HIF-1α being transfected into A549, the activity of MDR-1 was increased and the effect of 5-Fu was weakened. In conclusion, HIF-1α can promote chemoresistance by increasing the activation of MDR1 and suppressing apoptosis during lung cancer cells A549 induced with 5-Fu.

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.

Temperature effects of dark solitons on the self-deflection of bright solitons in a separate bright-dark soliton pair

Based on the theory of one-dimensional separate soliton pairs formed in a serial photorefractive crystal circuit, we investigated the temperature effects of the dark soliton on the self-deflection of the bright soliton in a bright-dark soliton pair. The numerical results obtained by solving the nonlinear propagation equation showed that the bright soliton moves on a parabolic trajectory in the crystal and its spatial shift changed with the temperature of the dark soliton. The higher the temperature of the dark soliton was, the smaller the spatial shift of the bright soliton was. The self-bending process was further studied by the perturbation technique, and the results were found to be in good agreement with that obtained by the numerical method.

Primary culture of alveolar epithelial type II cells and its bionomic study.

SummaryTo establish a better method of primary culture for alveolar epithelial type II cells (AEC II) and to study its bionomics, alveolar epithelial type II cells were isolated by digestion with trypsin and collagenase, which were then purified by plated into culture flask coated with rat immunoglobulin G. The purified AEC II were identified by alkaline phosphatase staining, electron microscopy, immunocytochemical staining of pulmonary surfactant protein A (SPA). The SPA expression and transfection characteristics were compared with those of A549 cell line. The results showed that AEC II could be isolated by digestion with trysin and collagenase and purified by adhesive purification by using IgG, with a yield of about 2–3 × 107, and a purity of about 75%–84%. Cells could be quickly identified with AKP staining. AEC II were different from A549 cell line in terms of SPA expression and transfection characteristics. It is concluded that adhesive purification with IgG can improve the purity of AEC II, and AKP staining is simple in cell identification. AEC II can not be completely replaced by A549 cells in some studies because the differences between them, such as SPA expression.To establish a better method of primary culture for alveolar epithelial type II cells (AEC II) and to study its bionomics, alveolar epithelial type II cells were isolated by digestion with trypsin and collagenase, which were then purified by plated into culture flask coated with rat immunoglobulin G. The purified AEC II were identified by alkaline phosphatase staining, electron microscopy, immunocytochemical staining of pulmonary surfactant protein A (SPA). The SPA expression and transfection characteristics were compared with those of A549 cell line. The results showed that AEC II could be isolated by digestion with trysin and collagenase and purified by adhesive purification by using IgG, with a yield of about 2–3 × 107, and a purity of about 75%–84%. Cells could be quickly identified with AKP staining. AEC II were different from A549 cell line in terms of SPA expression and transfection characteristics. It is concluded that adhesive purification with IgG can improve the purity of AEC II, and AKP staining is simple in cell identification. AEC II can not be completely replaced by A549 cells in some studies because the differences between them, such as SPA expression.

Self-Deflection of Dark Screening Spatial Solitons Based on Higher-Order Space Charge Field

The effects of higher-order space charge field on the self-deflection of dark screening spatial solitons in biased photorefractive crystals are numerically investigated under steady-state conditions. The expression for an induced space-charge electric field including higher-order space-charge field terms is obtained. Numerical results indicate that dark solitons possess a self-deflection process during propagation, and the solitons always bend in the direction of the c axis of the crystal. The self-deflection of dark solitons can experience considerable increase especially in the regime of high bias field strengths.

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.

Diffusion-induced deflection and the effect of two-wave mixing gain on dissipative photovoltaic solitons

In an open-circuit dissipative photovoltaic (PV) crystal, by considering the diffusion effect, the deflection of bright dissipative photovoltaic (DPV) solitons has been investigated by employing numerical technique and perturbational procedure. The relevant results show that the centre of the optical beam moves along a parabolic trajectory, while the central spatial-frequency component shifts linearly with the propagation distance; furthermore, both the spatial deflection and the angular derivation are associated with the photovoltaic field. Such DPV solitons have a fixed deflection degree completely determined by the parameters of the dissipative system. The small bending cannot affect the formation of the DPV soliton via two-wave mixing.