Antibody-nanoparticle Conjugate Constructed With Anti-HER2 Monoclonal Antibody And Nanoparticle Albumin-bound Paclitaxel For The Targeted Therapy Of Human Epidermal Growth Factor Receptor 2-positive Gastric Cancer

Objective:This study was to investigate antibody-nanoparticle conjugate(ANC,Anti-H/Nab-P)constructed with Anti-HER2 monoclonal antibody(Anti-HER2 mAB)and nanoparticle albumin-bound paclitaxel(Nab-paclitaxel)as a novel strategy of targeted therapy and nano drug delivery systems for human epidermal growth factor receptor 2(HER2)positive gastric cancer and discuss the possible mechanism.Methods:Firstly,the ANC was fabricated with Anti-H and Nab-paclitaxel by a "one-step"synthesis using EDC/NHS.In vitro study,the cell viability,apoptosis,western blot and cell cycle of the positive HER2 gastric cancer NCI-N87 cells were measured and compared in four groups of PBS,Taxol(?)(PTX),Abraxane(?)(Nab-paclitaxel)and ANC(Anti-H/Nab-P).In addition,GC xenograft models were established to evaluate antitumor effiency in vivo.When the experiment was done,these mice were sacrificed by cervical dislocation,and the liver,heart,lung,spleen,kidney and tumor tissues isolated from each group,the internal structure of the organization was tested by microscope.Furthermore,we chose the NIR797 to locate on the ANC and use the NIR imaging to demonstrate that the ANC could more precise target and delayed release of PTX.Results:ANC of Anti-H/Nab-P was spherical in shape and in a suitable size(139.18 ± 32.06)nm.In vitro,the half-maximal inhibitory concentration(IC50),defined as the concentration of PTX equivalent needed to kill 50%of cells,was found to be(0.24 ± 0.08)?g/ml,(0.13 ± 0.03)?g/ml and(0.048 ± 0.01)?g/ml for PTX,Nab-paclitaxel and ANC of Anti-H/Nab-P respectively for NCI-N87 cells with an excellent dose-effect relationship.Compared with PTX and Nab-paclitaxel,ANC of Anti-H/Nab-P could induce significant G2/M arrest.Expression of Bax,CLV-caspase-3,CLV-caspase-8 and CLV-caspase-9 in PTX group and Anti-H/Nab-P group compared to the control group,the gray value markedly increased.The opposite result was observed in Survivin,Bcl-2 expression,the gray value obviously decreased.The results showed the strongest Bax,CLV-caspase-3,CLV-caspase-8 and CLV-caspase-9 expression but the weakest Survivin,Bcl-2 expression in Anti-H/Nab-P group.In vivo,at 4 weeks after treatment,mice treated by ANC of Anti-H/Nab-P had a mean tumor volume of(233±24)mm3,Nab-paclitaxel of(559±97)mm3,PTX of(871 ±94)mm3 and PBS as control of(1576±190)mm3,and the RTV were 3.72 ±0.23,8.34 ± 0.51,13.20 ± 1.89,24.28 ± 3.25 respectively.Obviously,the ANC could surpasses Nab-paclitaxel and PTX in reducing tumor volume with lesser side effects.Furthermore,NIRF imaging indicated a better targeting and sustained release of PTX with ANC than that with Nab-paclitaxel and PTX.Conclusion:Antibody-nanoparticle conjugate of Anti-H/Nab-P could mediate targeted therapy and enhance antitumor activity,which could represent a novel targeted therapeutic agent for positive HER2 gastric cancer.