Effect of trichostatin A and paclitaxel on the proliferation and apoptosis of lung adenocarcinoma cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Histone deacetylase inhibitors can regulate gene expression through modulation of the degree of acetylation of histone and non-histone, thus affecting cell proliferation, survival and chemosensitivity. Histone deacetylase inhibitors combined with paclitaxel may enhance the inhibitory effect of drugs on lung cancer cells. This study aimed to observe the effect of trichostatin A (TSA)/paclitaxel on the proliferation and apoptosis in human A549 lung adenocarcinoma cells, and to investigate its mechanism.</p><p><b>METHODS</b>A549 cells were cultured in Dulbecco modified Eagle's medium (DMEM) in the presence of paclitaxel and the histone deacetylase inhibitor TSA, and the growth curve was obtained by trypan-blue exclusion assay and cell count. Apoptosis was assessed using Hoechst 33258 staining and flow cytometry analysis, and cell cycle was detected by flow cytometry analysis. The proteins poly ADP-ribose polymerase (PARP), caspase-3, survivin, and tubulin acetylation were detected by Western blotting.</p><p><b>RESULTS</b>A significant reduction of proliferation was observed in A549 lung adenocarcinoma cells treated by paclitaxel or TSA. Combined treatment with TSA/paclitaxel caused the greatest inhibition of cell proliferation. The combined treatment with TSA and paclitaxel induced more severe apoptosis, and significantly more cells were arrested in G2/M phase (P < 0.05) then with a single drug. Using Western blotting, we demonstrated that treatment with TSA/paclitaxel led to synergistic increase in acetylated tubulin, PARP, caspase-3, and reduced the expression of survivin.</p><p><b>CONCLUSION</b>TSA and paclitaxel have a synergistic activity that can inhibit cell growth and induce apoptosis.</p>

Relationship between epidermal growth factor receptor gene expression and radiosensitivity of non-small-cell lung cancer cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the relationship between epidermal growth factor receptor (EGFR) gene expression and radiosensitivity of non-small-cell lung cancer (NSCLC) cells.</p><p><b>METHODS</b>EGFR sequence-specific double-stranded RNA (dsRNA-EGFR) was chemically synthesized. NSCLC cell line SPC-A1 was transfected with dsRNA-EGFR formulated with Lipofectamine 2000. Western blot and real-time PCR were used to determine the EGFR mRNA and protein expression, respectively. Colony inhibition test was adopted to observe the radiosensitizing effect. To establish the nude mouse tumor models, calculate the tumor growth inhibition rate and make the tumor growth curve by measuring its size and weight.</p><p><b>RESULTS</b>EGFR mRNA levels were 1.51 ± 0.22, 1.38 ± 0.15 and 0.45 ± 0.11 in the control group, dsRNA-unrelated group and dsRNA-EGFR group, respectively (F = 482.7, P < 0.01). The contents of EGFR protein were 2340.87 ± 10.99, 2231.85 ± 35.66 and 832.03 ± 39.13 in the control group, dsRNA-unrelated group and dsRNA-EGFR group, respectively (F = 263.3, P < 0.05). Compared with the control group, dsRNA-EGFR sequence specifically decreased the expressions of EGFR mRNA by 70.2% and EGFR protein by 64.5%. The colony inhibition rates of the control group, dsRNA-unrelated combined with radiotherapy group and dsRNA-EGFR combined with radiotherapy group were 9.3%, 12.5% and 65.5%, and the tumor growth inhibition rates were 21.3%, 24.4% and 64.2%, respectively. The combination of dsRNA-EGFR and radiotherapy significantly inhibited the tumor growth in vitro and in vivo.</p><p><b>CONCLUSIONS</b>DsRNA-EGFR shows an apparent inhibitory effect on the expression of EGFR mRNA and protein of NSCLC cells, effectively inhibit the tumor growth in vivo, and enhance the radiosensitivity of NSCLC.</p>

Expression of Yes-associated protein in non-small cell lung cancer and its relationship with clinical pathological factors / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Yes-associated protein (YAP) plays an important role in signal transduction and gene transcription regulation in normal cells, with elevated and over-expressed YAP levels observed in various malignant tumors. The aim of this study was to investigate the expression of YAP in non-small cell lung cancer (NSCLC), and to study the possible relationship of YAP expression with the occurrence and development of NSCLC.</p><p><b>METHODS</b>YAP expression was assessed in 40 cases of NSCLC tumor tissues by immunohistochemistry, and their protein and mRNA levels were evaluated through Western blotting and reverse transcription-polymerase chain reaction (PCR), respectively. Normal lung tissues obtained from the same patient were used as control. Statistical analysis was performed to correlate the YAP expression to clinical pathological factors, such as tumor type, stage and grade.</p><p><b>RESULTS</b>YAP-positive expression was found in 28 (70%) of the 40 cases of NSCLC, which included 10 cases of squamous cell carcinoma (25%), 17 cases of adenocarcinoma (42.5%) and 1 case of squamous adenocarcinoma (2.5%). In the 28 YAP-positive cases, 19 cases showed lymph node metastasis and were classified in TNM stage II + III (47.5%); the other nine cases showed no lymph node metastasis (22.5%) and were classified in the TNM stage I. There was no relationship between YAP expression and patients' age, gender or tumor histological grades. However, YAP showed significant over expression in late period of T stage (P = 0.012), TNM stage (P = 0.039), and lymph node metastasis (P = 0.013), respectively. Notably, YAP-positive expression was significantly higher in adenocarcinoma than that in squamous cell carcinoma (P = 0.041).</p><p><b>CONCLUSIONS</b>Over-expression of YAP was associated with NSCLC, especially lung adenocarcinoma. The high YAP expression in late period of tumor stage and lymph node metastasis may indicate that YAP expression could be an early marker for NSCLC tumorigenesis.</p>

Effect of trichostatin A and paclitaxel on the growth and apoptosis of lung adenocarcinoma cell lines / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effect of trichostatin A (TSA)/paclitaxel on the growth and apoptosis in human lung adenocarcinoma cell line A549 cells.</p><p><b>METHODS</b>Human lung adenocarcinoma A549 cells were cultured in DMEM in the presence of paclitaxel and the histone deacetylase inhibitor trichostatin A, and the growth curve was obtained by trypan-blue exclusion assay and cell count. Apoptosis was assessed using Hoechst 33258 staining and flow cytometry, and cell cycle was detected by flow cytometry analysis. The proteins of PARP, caspase-3, survivin and tubulin acetylation were detected by Western blotting.</p><p><b>RESULTS</b>Significant growth reduction was observed in the A549 cells following treatment with paclitaxel or the histone deacetylase inhibitor TSA. The combined treatment with TSA/paclitaxel caused the highest inhibition of cell growth. The apoptosis rate of A549 cells treated with TSA or paclitaxel for 24 hours was (17.6 ± 1.8)% and (39.2 ± 3.7)%, respectively, but a significantly higher apoptosis rate was (64.2 ± 4.2)% was induced by combined treatment with TSA and paclitaxel. In contrast with the control group, the cell cycle was markedly arrested at G2/M phase in the TSA and paclitaxel group (P < 0.05). The Western blot analysis demonstrated that treatment with TSA/paclitaxel led to a synergistic increase of acetylated tubulin, PARP and caspase-3, and reduced the expression of survivin.</p><p><b>CONCLUSION</b>TSA or paclitaxel alone can inhibit the cell growth and induce apoptosis, and the combination of TSA and paclitaxel exerts a synergistic effect on the growth and apoptosis in lung adenocarcinoma cells.</p>

Effect of Glucocorticoid in mice of asthma induced by ovalbumin sensitisation and RSV infection.

Objective: To investigate the inflammatory changes and the airway hyper-responsiveness in the asthma mouse model infected by respiratory syncytial virus and elucidate the relationship between the infection and the effect of glucocorticoid. Methods: 60 BALB/c mice were randomly divided into 6 groups. One of these is the control group; the others are the OVA/sham group, the OVA/sham +Dex group, the PBS/RSV group, the OVA/RSV group and the OVA/RSV+Dex group. The airway resistance was measured using a sealed body plethysmograph. Pathological slides were stained with hematoxylin-eosin, and the peribronchial inflammation was observed microscopically. The concentrations of IL-4、IFN-γ、TGF-β1 in lung tissues were detected by ELISA. Results: Compared with the control group, the degree of the airway inflammation and hyper-responsiveness and the concentrations of IL-4/IFN-γ、TGF-β1 in all four OVA groups increased significantly. And there was a statistically significant difference between the OVA/sham group and the OVA/sham+Dex group, and between the OVA/RSV group and the OVA/RSV+Dex group respectively. Compared with the OVA/RSV group，there was an obvious aggravation of airway inflammation and hyper-responsiveness in the OVA/RSV+Dex group. Conclusions: Glucocorticoid significantly reduces airway inflammation and hyper-responsiveness induced by repetitive OVA challenge in the mouse model of asthma. However, the significant decrease in Th1 and increase in Th2 inflammation and aggravation of airway hyper-responsiveness in the mice in OVA/RSV group show that they are not sensitive to glucocorticoid. The effects of infection with RSV on the mouse model of asthma could be the cause of the glucocorticoid resistance during the therapy.