The Combination Inhibition Of Eicosapentaenoic Acid And Etoposide On Human Lung Cancer Cell Lines A-549

Objective:To explore the combination effect of eicosapentaenoic acid (EPA) and etoposide on human lung cancer cell lines A-549.Methods:The apoptosis induced by EPA and etoposide on human lung cancer cell lines A-549was detected by the3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and morphology observation. The flow cytometry (FCM) was used to investigate the apoptosis and the changes of cell cycle.The expression changes of Ki-67、Bcl-2、Bax、Fas、Caspase-3、Caspase-8、Caspase-9、Survivin、Livin and nuclear factor kappa B (NF-KB) were detected by immunohistochemitry. The change of the telomerase activity was detected to investigate the effect of EPA and etoposide on A-549cell lines. The tumors diameter measurement、ascites volume and the counts in ascites of rat model were detected to study the effect of EPA and etoposide in vivo.Results:1The antitumor activity detected by MTT in48hrs:Control group vs EPA40μg/ml group (2.06±0.56vs10.29±1.74,P=0.000),EPA40μg/ml&etoposide10μg/ml group vs etoposide10μg/ml group (33.41±3.44vs44.50±3.71,P=0.000),EPA40μg/ml&etoposide10μg/ml group vs etoposide20μg/ml group (44.64±4.77vs44.50±3.71,P=0.9288),EPA40μg/ml&etoposide20μg/ml group vs etoposide20μg/ml group (50.72±4.61vs44.64±4.77,P=0.000).2Morphologic observation:The counts of apoptosis cells were raised in experiment groups,especially in conjunction groups.3ROS:The optical density(OD) was more increased in experiment groups than control group(P<0.05).4FCM:The percentage of cells in Go/G1phase were decreased and cells in S&G2/M phase were increased, it suggested that human lung cancer cell lines A-549were blocked in S&G2/M phase.5Immunocytochemistry:The results of Immunocytochemistry showed that the expressions of Bcl-2、Ki-67、 NF-κB、Survivin and Livin were reduced, and those of Fas、Bax、Caspase-3、 Caspase-8and Caspase-9were increased in experimental groups. There were significantly difference between the group of control and EPA40μg/ml, and the groups of etoposide and EPA40μg/ml in conjunction with etoposide.6Telomerase:The telomerase activity were decreased in experimental groups. Control group vs EPA40μg/ml group (94.00±5.48vs86.00±5.48,P=0.0497), etoposide group vs EPA in conjunction with etoposide group(64.00±11.40vs50.00±7.07,P=0.0479).7Rat model: The mice tumor size, ascites volume and the counts in ascites of rat model were all reduced. And there were significantly difference between the group of control and EPA, and the group of etoposide and EPA in conjunction with etoposide.Conclusions:1、EPA has the antineoplastic effect.2、The combined inhibition of EPA and etoposide is stronger than etoposide only.3、EPA can reduce the dose of etoposide in Vitro.