Study Of Reversal Effect Of Recombinant Human Endostatin Combine With Polysaccharide Of Trametes Robiniophila Murr On Chemotherapy Resistance In Human Lung Adenocarcinoma A549/DDP Cells

Objection: To investigates the reversal effect and mechanism of RecombinantHuman Endostatin combine with Polysaccharide of Trametes Robiniophila Murr onChemotherapy Resistance in Human Lung Adenocarcinoma A549/DDP Cells.Method: This experiment use Lung adenocarcinoma cell line A549and itsDDP-resistant cell line A549/DDP as a objective of study.Lung adenocarcinoma cellline A549and its DDP-resistant cell line A549/DDP were treated with DDP combinedwith Endostatin, DDP combined with Polysaccharide of Trametes Robiniophila Murrand mixture.Difference in drug resistance was analyzed between different regimens andbetween different cell lines (A549versus A549/DDP), after a72h-treatment in vitro.MTT analyzed the growth inhibition by rh-Endostatin, Polysaccharide of TrametesRobiniophila Murr and DDP in A549or A549/DDP. Rh-Endostatin,and Polysaccharideof Trametes Robiniophila Murr were used to determine non-cytotoxic concentration ofrh-Endostatin,and50％inhibited concentration for DDP， and to determineDDP-resistance index in A549/DDP. MTT analyzed50％inhibited concentration byrh-Endostatin combined with DDP，Polysaccharide of Trametes Robiniophila Murrcombined with DDP and mixsture in A549or A549/DDP. The expression of resistantproteins(P-gp、LRP) were analyzed with western blot in A549/DDP treated with DDP、rh-Endostatin combined with DDP、Polysaccharide of Trametes Robiniophila Murrcombined with DDP and mixsture.Results:1. MTT: The observed50％inhibited concentration (IC50) for DDP was(0.79±0.06) ug/ml in A549and (13.3±0.9) in A549/DDP respectively. TheDDP-resistance index in A549/DDP was16.8. rh-Endostatin at400ug/ml showed no cytotoxicity in either A549or A549/DDP after72h-treatment. Polysaccharide ofTrametes Robiniophila Murr at0.4mg ml showed no cytotoxicity in either A549orA549/DDP after72h-treatment.2. MTT: The observed50％inhibited concentration (IC50) for rh-Endostatincombined with DDP was (2.57±0.04) ug/ml in A549and (0.31±0.04) in A549/DDPrespectively. The DDP-resistance index in A549/DDP was5.18.The observed50％inhibited concentration (IC50) for Polysaccharide of TrametesRobiniophila Murr combined with DDP was (0.48±0.04) ug/ml in A549and(4.21±0.04) in A549/DDP respectively. The DDP-resistance index in A549/DDPwas3.16.The observed50％inhibited concentration (IC50) for Polysaccharide of mixsturewas (0.22±0.04) ug/ml in A549and (1.73±0.04) in A549/DDP respectively. TheDDP-resistance index in A549/DDP was7.69.3. Western blot: An obvious drop in expression level of either P-gp or LRP wasnoticed in A549/DDP treated with Endostatin-Trametes Robiniophila Murr-DDPcombination with statistical significance.(P=0.00,in DDP group comparison).Theexpression of P-gp or LRP treated with Endostatin-Polysaccharide of TrametesRobiniophila Murr-DDP combination was lower then which treated with Polysaccharideof Trametes Robiniophila Murr combined with DDP (P=0.012,in DDP groupcomparison). or rh-Endostatin combined with DDP.(P=0.031,in DDP groupcomparison).Conclusion: Rh-Endostatin combined with Polysaccharide of TrametesRobiniophila Murr have synergies of reversing DDP-resistance in A549/DDP cells,with a probable mechanism relating to lowered expression of P-gp and LRP.