Mechanism Study Of PD-1 Antibody Combined With Docetaxel In The Treatment Of Prostate Cancer In Mice

Objective By establishing mouse prostate cancer Model in vivo,this study aims to observe the anti-tumor effect of PD-1 Antibodys and Docetaxel used alone and combined together in tumor-bearing mice.Besides,the experiment also targeted at exploring the role of PI3K/AKT/NFκB-P65 signaling in treatment group of PD-1 Antibodys and Docetaxel alone and combined together,in order to provide a safe and synergistic combination strategy for clinical treatment of prostate cancer.Methods 1.The tumor bearing mouse model of C57BL/6 male mice was established by subcutaneous injection of RM-1 prostate cancer cells.When the tumor diameter reached 3 mm,The mice were divided into model group(PBS),PD-1 antibody single group(200 μg/kg),docetaxel single group(10 mg/kg),combined group 1(PD-1 antibody 200 μg/kg~+docetaxel 10 mg/kg),and combined group 2(PD-1 antibody 200 μg/kg~+docetaxel 5 mg/kg).2.The length and diameter of the mouse tumor were accurately measured with vernier caliper during the treatment,and the volume changes were calculated.3.The mice were sacrificed by neck removal after completion.The number of CD4~+and CD8~+T cells in spleen and invasive CD4~+and CD8~+T cells in tumor tissue were detected by flow cytometry and immunohistochemistry to observe the effects of different treatment regiments on the immune function of mice.4.Immunohistochemistry was used to detect the expression of PD-L1 in tumor tissue to evaluate the therapeutic effect on prostate cancer in mice;5.The expressions of PI3K,AKT,P-AKT,NFκB-P65,P-NFκB-P65,PD-L1,BCL2 and BAX in tumor were detected by Western blot,so as to further explore the mechanism of the therapeutic regimen set in this experiment.Results Compared to the Model Group(PBS),PD-1 Antibody Camrelizumab alone group(200 μg/mouse)and Docetaxel alone group(10 mg/kg)treated mice,can slow down the growth curve of the mouse tumor volume over time,reduce the tumor weight,and improve the survival time of the mice to some measures.In addition,there is no obvious damage to the spleen,liver,kidney and other diseases.It also improves the immune function.But the combination of both drugs later showed better antitumor effects,especially when half reduction of Docetaxel is combined with the PD-1 Antibody,the synergistic effect is even more obvious.According to the results of immunohistochemistry and wetern blot,although Docetaxel alone had anti-tumor effect,it induced the expressio of PD-L1 and NFκB-P65 in tumor,which may reverse its inherently great anti-tumor benefit due to the dose.However,the therapy which combined PD-1 Antibody and Docetaxel together could deregulated the expression of PI3K,AKT,P-AKT,NFκB-P65,P-NFκB-P65,PD-L1,BCL2 and BAX in tumor,showed stronger anti-tumor results in tumor volume and weight and increased the number of CD4~+and CD8~+T cells in the tumor-bearing mice,bring better anti-tumor effect and good prognosis.Conclusion In the treatment of prostate cancer in mice,PD-1 antibody combined with docetaxel can increase the number of CD4~+and CD8~+immune cells in spleen and tumor,inhibit the expression of PI3K/AKT/NFκB-P65 signaling pathway,and promote the apoptosis of tumor cells.The combination of PD-1 antibody and docetaxel has a synergic effect,and has no obvious damage to organs,so it is a safe and feasible combination therapy.