Effect of phillygenin on inflammatory response of A549 cells induced by lipopolysaccharide and normal human plasma / 中国药理学通报

Aim To investigate the effect of phillygenin ( PHI) on lipopolysacchride ( LPS) and normal human plasma ( NHP) induced inflammatory injury on alveolar type II epithelial A549 cells and the related mechanism. Methods A549 cells were exposured to 1 mg • L

Study of electrophysiological mechanism of dopamine inhibiting insulin secretion by Kv channels / 中国药理学通报

Aim To study the electrophysiological mechanism of dopamine inhibiting insulin secretion hv voltage-dependent potassium ( Kv) channels.Methods Islets and (3 cells were isolated from male SD rats.D,-like receptor agonist ( SKP38393), D2-like receptor agonist (Quinpirole) and antagonist (Epiclopride) were used according to the experiment.Insulin secretion was detected by insulin radioimmunoassay.Whole-cell j J patch-clamp technique was applied to detect Kv channel currents and action potential duration of p cells.Di- BAC4(3) staining was used to observe membrane potential.Results SKF38393 did not affect insulin secretion and the Kv channel currents.Quinpirole signifi cantly inhibited insulin secretion and increased Kv channel currents.Dopamine significantly inhibited insulin secretion, increased Kv channel currents and shortened action potential duration of p cells, which could be reversed by epiclopride.In addition, dopamine de-creased membrane potential of INS-1 cells.Conclusions Dopamine inhibits insulin secretion by acting on D2-like receptors, resulting in actived Kv channels, shortened action potential duration and decreased cell membrane potential.

The influence of subjective comfort of working environment on occupational stress of railway station workers / 中华劳动卫生职业病杂志

Objective: To explore the influential factors of job stress suffered by workers in railway stations, the level of job stress of were measured and subjective comfort of employees targeting to working environment were reported. Methods: In March 2019, a cluster sampling study was designed to collect the personal characteristics, job characteristics and subjective comfort degree of working environment of 432 employees in Chongqing railway stations. Meanwhile, job stress was assessed using the effort-reward imbalance scale. Chi-square test was used to compare the difference of occupational stress detection rate among different stratified factors such as occupational characteristics. Logistic regression was applied to analyze the influential factors of occupational stress. Results: The detection rate of job stress of workers in the railway stations was 31.02% (134/432) . The detection rate of job stress was higher among the divorced workers in railway stations, those earning less than 5, 000 yuan per month, those with 10-20 years' length of service, those who worked as a conductor and other workers including baggageman, station master on duty and assistant engineer (χ(2)=9.61, 14.76, 23.28, 11.06, P=0.008, 0.002, 0.000, 0.011) . The detection rate of job stress was higher among those whose working environment subjective feelings were uncomfortable, the differences were statistically significant (P<0.001) . The results showed that the occupational stress of the staff in the railway stations was influenced by their subjective feeling of air quality, noise and Space Layout (P<0.05) . The risk factors of occupational stress were air quality, noise and uncomfortable space layout (OR=0.571, 0.068, 0.441, P=0.051, 0.054, 0.007) . Conductor, other (Bellboy, Duty Station Master, assistant engineer) were the risk factors of occupational stress (OR=1.884, 2.703, P=0.065, 0.019) . The employees of station A and station B were the risk factors of occupational stress (OR=4.681, 1.811, P=0.002, 0.067) . Conclusion: The higher detection rate of job stress of workers in the railway stations is correlated with the subjective comfort degree of the working environment of the workers.

HER-2 expression in local advanced breast cancer and the efficacy of neoadjuvant chemotherapy regimens / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the relationship between HER-2 expression and the efficacy of neoadjuvant chemotherapy in local advanced breast cancer.</p><p><b>METHODS</b>Different neoadjuvant chemotherapy regimens, namely CMF, CEF, and NEF, were administered in 132 patients with local advanced breast cancer for 2 cycles, each lasting for 28 days. According to the criteria recommended by WHO, the efficacy and safety of the regimens were evaluated after two cycles of neoadjuvant chemotherapy. HER-2 expression was examined by immunohistochemistry using specific monoclonal antibodies before chemotherapy and after surgery.</p><p><b>RESULTS</b>The overall response rate (RR) of CMF, CEF, and NEF regimens were 39.5% (17/43), 54.3% (25/46) and 72.1% (31/43), with incidence of leukopenia of 34.9% (15/43), 58.7% (27/46) and 60.5% (26/43), respectively. Other adverse effects including decreased hemoglobin (Hb) level, thrombocytopenia, gastrointestinal irritation and alopecia were similar between the 3 groups (P>0.05). No significant variation in HER-2 expression occurred after administration of the 3 regimens. The overall RR to CMF regimen in HER-2-negative breast cancer patients was significantly higher than that in HER-2-positive patients, but showed no significant difference with CEF and NEF regimens.</p><p><b>CONCLUSION</b>HER-2 expression is not decreased after neoadjuvant chemotherapy in breast cancer patients, and HER-2-positive breast cancer can be resistant to CMF regimen, but not to CEF and NEF regimens.</p>

Chemopreventive effect of celecoxib against DMBA-induced breast cancer and its mechanism / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the chemopreventive effect of celecoxib, a specific cyclooxegenease-2 (COX-2) inhibitor, on chemically induced breast cancer of rats and its effect on COX-2 expression.</p><p><b>METHODS</b>7, 12-dimethylbenz anthracene (DMBA) was administered intragastrically in SD female rats to establish breast cancer models, which were divided subsequently into control group, tamoxifen group and celecoxib group to receive different treatments accordingly. The occurrence rate of breast cancer was observed and the effect of celecoxib on COX-2 and vascular endothelial growth factor (VEGF) expressions assayed by immunohistochemical SP method.</p><p><b>RESULTS</b>The incidence of breast cancer in tamoxifen group (48.15%) and celecoxib group (50.00%) were both significantly lower than that in the control group (85.71%; P=0.003 and P=0.004, respectively). The positivity rate of COX-2 expression in celecoxib group (28.57%) was significantly lower than those of tamoxifen group (48.15%) and control group (83.33%; P=0.001 and P=0.035, respectively). The positivity rate of VEGF expression in celecoxib group (42.86%) was significantly lower than that of control group (79.17%, P=0.023), but comparable with that in tamoxifen group (46.15%, P=0.863).</p><p><b>CONCLUSION</b>Celecoxib can significantly suppress DMBA-induced breast cancer in female rats possibly through down-regulation of COX-2 and VEGF expressions.</p>

siRNA targeted against survivin induces apoptosis of pancreatic cancer cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of a sequence-specific small interfering RNA (siRNA) in suppressing survivin expression and cell proliferation and inducing apoptosis of PC-2 cells.</p><p><b>METHODS</b>The plasmid expression vector of siRNA targeted against survivin was constructed and transfected into PC-2 cells with Lipofectamine 2000. The changes of survivin expression were detected by semi-quantitative RT-PCR and immunohistochemical SP methods. The effect of siRNA in suppressing the proliferation of PC-2 cells was detected by MTT assay, and its role in inducing PC-2 cell apoptosis evaluated by flow cytometry.</p><p><b>RESULTS</b>The sequence-specific siRNA effectively suppressed survivin expression at both mRNA and protein levels with inhibition rate of 81.25% at mRNA level and 74.24% at protein level. Survivin expression suppression significantly inhibited the proliferation of PC-2 cells, and at 24 and 48 h after cell seeding, the proliferation inhibition rate was 28.00% and 33.38% respectively; 24, 48 h after the transfection, apoptosis occurred in 8.46% and 7.53% of the cells, respectively.</p><p><b>CONCLUSIONS</b>The plasmid expression vector for the siRNA against survivin constructed in the study can effectively and specifically suppress survivin expression in PC-2 cells, and blocking survivin expression suppresses PC-2 cell proliferation and induces cell apoptosis. siRNA targeted against survivin has a potential value in gene therapy for pancreatic cancer.</p>

Effects of siRNA targeted to survivin in suppressing proliferation and inducing apoptosis in breast cancer MCF-7 cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>Blocking the expression of survivin with RNA interference techniques, the effects of suppressing proliferation and inducing apoptosis of breast cancer MCF-7 cells were investigated.</p><p><b>METHODS</b>A siRNA eukaryotic expression vector against survivin was constructed and transfected into breast cancer MCF-7 cells with lipofectamine 2000. The changes of survivin expression were detected by semi-quantitive RT-PCR and immunohistochemistry. The effect of suppressing proliferation of MCF-7 cell was detected by MTT assay. The effect of inducing MCF-7 cell apoptosis was detected by TUNEL assay.</p><p><b>RESULTS</b>The sequence-specific siRNA can efficiently block the expression of survivin both at mRNA and protein levels. The expression inhibition rate was 64.9% at mRNA level detected by semi-quantitive RT-PCR and 79.7% at protein level detected by immunohistochemistry. Blocking the expression of survivin can suppress proliferation of MCF-7 cells significantly. At 24 and 48 h after the cells were reseeded, the proliferation inhibition rates were 31.6% and 33.0%, respectively. At 24 h after transfection, apoptosis was induced in 12.9% of the cells as detected by TUNEL assay.</p><p><b>CONCLUSION</b>Blocking the expression of survivin with RNA interference technology can significantly suppress proliferation of MCF-7 cells and induce apoptosis to a certain degree. RNAi targeted to survivin has a potential value in gene therapy of breast cancer.</p>

Synergism between a siRNA targeted to survivin and 5-FU in inhibiting MCF-7 cell proliferation in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of small interfering RNA (siRNA) targeted to survivin in combination with 5-fluorouracil (5-FU) in inhibiting the proliferation of MCF-7 cells.</p><p><b>METHODS</b>A siRNA targeted to survivin was synthesized and transfected into MCF-7 cells via lipofectin. Changes of the cell growth activity in response to combined treatment with survivin siRNA and 5-FU or 5-FU treatment alone was evaluated by MTT assay. The Q method of Jin Zhenjun was used to evaluated synergism between the synthesized siRNA and 5-FU.</p><p><b>RESULTS</b>Treatment with 5 nmol/L siRNA reduced the IC50 of 5-FU from 4.42 to 1.18 microg/ml, and the inhibitory effect of combined treatment on MCF-7 cells was higher than that of 5-FU alone (F=26.74, P<0.01). Synergism effect was observed between 5-FU at lower concentrations and survivin siRNA.</p><p><b>CONCLUSION</b>siRNA may enhance the effectiveness of 5-FU in inhibiting the proliferation of MCF-7 cells.</p>

Knockdown of survivin expression by small interfering RNA suppresses proliferation of two human cancer cell lines / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To construct an expression vector of small interfering RNA (siRNA) against survivin and observe its effects on survivin expression and proliferation of human pancreatic cancer cell line PC-2 and breast cancer cell line MCF-7.</p><p><b>METHODS</b>Constructed an expression vector of siRNA against survivin and transfected it into PC-2 and MCF-7 cells using lipofectamine 2000. The expression of survivin was detected by semi-quantitive RT-PCR and immunohistochemistry, and its effects on proliferation of PC-2 and MCF-7 cells were detected by MTT assay.</p><p><b>RESULTS</b>The introduction of sequence-specific siRNA could efficiently suppress survivin expression at both mRNA and protein levels in the two cancer cell lines. In PC-2 cells, the expression inhibition rates were 81.25% at mRNA level and 74.24% at protein level. In MCF-7 cells, the expression inhibition rates were 64.91% at mRNA level and 79.72% at protein level. The proliferation of PC-2 and MCF-7 cells was also suppressed, and 24 and 48 hours after the cells were reseeded, the proliferation inhibition rates of PC-2 cells were 28.00% and 33.38%, and that of MCF-7 cells were 31.58% and 33.02%, respectively.</p><p><b>CONCLUSIONS</b>The expression vector of siRNA against survivin can block survivin expression in PC-2 and MCF-7 cells efficiently and specifically. Down regulation of survivin expression can suppress proliferation of PC-2 and MCF-7 cells. Survivin RNAi may have potential value in gene therapy of human cancers.</p>