ABSTRACT
Aim To investigate the effect of hesperidin on human lung cancer cell A549 and the possible mechanism.Methods The cell apoptosis and necrosis of A549 treated with hesperidin were measured by the Hoechst 33342/PI fluorescent dye based on microfluidic chip technology.Cell cycle and apoptosis rate were evaluated by flow cytometry(FCM).The expressions of the related genes were detected through the real-time fluorescent quantitative PCR technology(RT-PCR) including VEGF, PI3K and PTEN.The protein expressions of Bcl-2, Cyclin B1, PI3K, Akt and PTEN were detected by Western blot after hesperidin intervention.Results The proliferation of A549 cells was significantly inhibited by hesperidin in a dose-dependent manner.FCM results showed that hesperidin could not only influence the G0/G1 phase and S phase, but also promote the apoptosis of lung cancer cells.Meanwhile, the apoptosis and necrosis rate was increased from(6.7±0.6)% to(27.9±1.1)% compared with that of control group(P<0.05).From the level of molecular, the gene expressions of VEGF and PI3K were decreased, while the PTEN was increased after hesperidin stimulation.Western blot results showed that the expression of protein Bcl-2, Cyclin B1 and Akt were decreased, which all showed close relationship with cell apoptosis, cell cycle and PI3K-Akt signaling pathway.The expression of PI3K was increased, but the change of PTEN was not statistically significant compared with that of control group.Conclusion Hesperidin induces lung cancer cell apoptosis through PI3K-Akt signaling pathway, which blocks cancer cell division and destroys the balance of related protein expression.
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Objective To study the effects of restructuring tissue inhibitor of matrix metatloproteinase-3 (rhTIMP-3) in combination with cisplatin (DDP) on the growth and apoptosis of A549 lung cancer cell line.Methods We made individual and combined use of different concentrations of rhTIMP-3 and DDP on A549 cells.Methyl thiazoyl terazolium (MTT) colorimetry was used to analyze cell growth inhibition,and flow cytometry technique was used to determine the cell cycle distribution and apoptosis rate.Results rhTIMP-3 and DDP both could inhibit the proliferation of A549 cells.rhTIMP-3 exerted its effect in the time-and concentration-dependent manners while DDP did so in the concentration-dependent manner;both induced the apoptosis of A549 cells.rhTIMP-3 could make the cells stay in S and G2/M phases,and DDP made the cells stay in S phase.The combination of them obviously strengthened the inhibition of A549 cell growth,and had obvious synergy in inducing apoptosis.Conclusion Both rhTIMP-3 and DDP can inhibit the proliferation of A549 cells and induce their apoptosis.The combined use of them not only can increase the inhibition of cell growth but also has synergy in inducing cell apoptosis.
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Objective To investigate the effect of PM2.5 airborne particulate matter with a mean diameter of less than 2.5μm exposure on autophagy and explore the links between autophagy and apoptosis in human lung cancer cells(A549). Methods A549 cells were exposed to 100μg/mL PM2.5 with or without 3-MA(autophagy inhibitor)for various periods of 0、2、4、12 or 24 hrs. Autophagy in A549 cells was assessed by determining the lev-el of LC3(a known autophagy marker)using confocal microscopy. The level of microtubule-associated protein 1 light chain 3(LC3) Ⅱ conversion and Bax (a pro-apoptotic protein) was detected by western blotting. Results The expression of LC3 and the ratio of LC3-II/LC3-I in A549 cells was significantly increased and Bax was signifi-cantly decreased following exposure to PM2.5100 μg/mL for 24 h in a time-dependent manner(P < 0.05). After treated with 100 μg/mL PM2.5,the formation of LC3 in A549 cells as evidenced by the intensity of intracellular fluorescence was significantly increased ,and autophageosomes were observed around nucleus in A549 cells. Fur-thermore blockage of autophagy by 3-MA led to a significant increase in the pro-apoptotic protein Bax. Conclu-sion PM2.5 exposure induces autophagy which may protect against apoptosis induced by PM2.5 in A549 cells.
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Objective To investigate whether there is an inhibition of the human lung cancer cell line A549 induced by the culture supernatant of Toxoplasma gondii in vitro and the mechanism of the inhibition. Methods A549 cells 5 x 10~4mL~(-1) were cultured and harvested. The cells were treated for different hours with different concentrations of Toxoplasma gondii culture supernatant (the concentrations of tachyzoites were 4×10~7mL~(-1), 8 × 10~7mL~(-1), 16 ×10~7mL~(-1) respectively). Growth inhibition rate was measured with the MTT method; Cell cycle was checked with flow cytometer. Western blot was used to detect the level of cyclinBl and cdc2 of cells. Results The culture supernatants of Toxoplasma gondii inhibited proliferation of A549 cells in a time-dose dependent manner. Cell cycle was significantly stopped at G_2/M phase by the culture supernatants with FCM technology. The culture supernatant of Toxoplasma gondii reduced the expressions of gene cyclinBl and cdc2 of A549 cells. Conclusion The culture supernatant of Toxoplasma gondii may inhibit A549 cell and arrest the cell cycle of A549 cells mainly by regulating the expression of gene cyclinBl and cdc2.
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Objective To investigate the inhibitory effects of CIK cell on apoptosis of lung cancer cell A549 in vivo. Methods CIK cells were induced by culturing PBMC with regular method and cell apoptosis was detected.Results Electron microscopic observations showed that CIK cells could induce the lung cancer cells A549 to apoptosis. Flow cytometry(FCM)demonstrated that apoptosis cells of lung cancer cells A549 were increased in CIK group as compared with the control group. Conclution CIK cells can induce the apoptosis of lung cancer cells A549.