Study Of Sensitized DC-BxPC-3 Tumor Vaccine Inducing Immune Effector Cells To Inhibit Pancreatic Cancer And Safety Evaluation In Vivo And Vitro Experiments

Background:Pancreatic carcinoma(PC)is a malignant tumor of the digestive system with extremely high mortality.The main clinical treatments include surgical resection,radiotherapy or chemotherapy,and its clinical efficacy is not ideal and the prognosis is poor.In recent years,tumor immunotherapy has achieved anti-tumor effects by improving autoimmunity,and has played an important role in tumor treatment.Dendritic cells(DCs)are important professional antigen-presenting cells in the body.They can induce the production of effector T cells by ingesting and processing antigens.At the same time,they can enhance the effect through high expression of costimulatory molecules and adhesion molecules.The ability of T cells to recognize and kill tumor cells.To provide experimental basis for clinical application of DC-Bx PC-3 tumor vaccine to treat pancreatic cancer,we studied the biological safety of sensitized DC-Bx PC-3 tumor vaccine and inhibiting the growth of pancreatic cancer cells in vivo and vitro.Objective:To evaluate the antitumor effect of sensitized BXPC-3 tumor vaccine by inducing systemic immune effector cells to inhibit BXPC-3 in vitro,and then to evaluate the safety of BXPC-3 tumor vaccine by BXPC-3 tumor induction in BALB/C nude mice.Methods:In vitro cell experiment:the experiment was divided into five groups:sensitive DCs tumor vaccine induction group,DCs tumor vaccine induction group,sensitive DCS induction group,1640 medium negative control group and blank group.CCK-8 method and annexin V-FITC/PI method were used to observe the inhibition and promotion of BXPC-3 apoptosis.In vivo safety evaluation:BALB/c nude mice were randomly divided into 6 groups:DC-Bx PC-3 tumor vaccine experimental group,sensitized DC positive control group,Bx PC-3 heat treatment group,Bx PC-3 lysate positive control group,Bx PC-3 Positive control group and negative culture medium control group,each group of mice were injected subcutaneously(4.0×103/μL,0.25m L/mouse),each group of mice was observed for tumors and tumor growth every 5days,a total of 40 days;In vivo efficacy study of sensitive DC-Bx PC-3 tumor vaccine inducing SIEC against pancreatic cancer:Establish a BALB/c nude mouse subcutaneous pancreatic cancer model,randomly divided into 6groups:sensitized DC-Bx PC-3 tumor vaccine+SIEC group,DC-Bx PC-3 tumor vaccine+SIEC group,sensitized DC+SIEC group,DC+SIEC group,the SIEC group and the negative control group,the corresponding vaccine(2.0×10~4/μL,0.25m L/mouse)was inoculated on the same side of the tumor growth,and the negative control group was inoculated with culture medium.Observe the tumor growth of each group every 5 days.At 40 days,the tumor inhibition rate was calculated,and the pathological changes of transplanted tumors in the scapular area of mice were observed by HE staining method.In vivo efficacy study of sensitive DC-Bx PC-3 tumor vaccine inducing T lymphocytes against pancreatic cancer:Establish a BALB/c nude mouse subcutaneous pancreatic cancer model,randomly divided into 6 groups:sensitized DC-Bx PC-3 tumor vaccine+T lymphocytes group,DC-Bx PC-3 tumor vaccine+T lymphocytes group,sensitized DC+T lymphocytes group,DC+T lymphocytes group,the T lymphocytes group and the negative control group,the corresponding vaccine(2.0×10~4/μL,0.25m L/mouse)was inoculated on the same side of the tumor growth,and the negative control group was inoculated with culture medium.Observe the tumor growth of each group every 5 days.At 40 days,the tumor inhibition rate was calculated.Results:Results of in vitro cell experiment:when the ratio of DCs to BXPC-3 was10:1,5:1,1:1 and 1:5,8.18%,11.9%,40.0%and 18.9%of the cells fused,respectively;the inhibition rate of sensitive BXPC-3,BXPC-3 and sensitive DCs induced siecs on BXPC-3 was 53.1%,45.3%,78.8%,respectively.The total apoptosis rate of BXPC-3 induced by sensitive DC fusion tumor vaccine,DC fusion tumor vaccine,sensitive DCs and DCs was 24.17%,11.43%,85.87%,29.94%and 21.60%,respectively.In vivo safety evaluation:Except for the Bx PC-3 positive control group,there was no tumor in the inoculation area of the other groups.In vivo efficacy study of sensitive DC-Bx PC-3 tumor vaccine inducing SIEC against pancreatic cancer:The experiment found that on the 15th day of inoculation,subcutaneous tumors appeared in the sensitive DC+SIEC and DC+SIEC groups and the negative control group.On the 20th day,the mice in each group developed subcutaneous tumors;on the 40th day,each group had small tumors.It can be seen from the pathological section of the mouse that a large number of cell necrosis occurred in the subcutaneous tumor tissue of the negative control group.Compared with the negative control,the sensitive DC-Bx PC-3 tumor vaccine+SIEC group(p<0.01),the DC-Bx PC-3 tumor vaccine+SIEC group(p<0.01)and the sensitive DC+SIEC group(p<0.05)have obvious tumor growth inhibitory effects.In vivo efficacy study of sensitive DC-Bx PC-3 tumor vaccine inducing T lymphocytes against pancreatic cancer:Compared with the negative control,the sensitive DC-Bx PC-3 tumor vaccine+T lymphocyte group,the DC-Bx PC-3 tumor vaccine+T lymphocyte group,the sensitive DC+T lymphocyte group,the DC+T lymphocyte group and the T lymphocyte group all have tumors The effect of growth inhibition,the data is statistically significant(p<0.05).Conclusions:When the DCs are mixed Bx PC-3 with 1:1,the fusion efficiency was the highest and the fusion rate was as high as 40%;The DCs vaccine obtained by BXPC-3 sequential method has a certain effect on inhibiting tumor cells in vitro.Sensitive DC-Bx PC-3 tumor vaccines and other tumor immune vaccines have good biological safety;Sensitive DC-Bx PC-3 tumor vaccines,DC-Bx PC3 tumor vaccines and sensitive DC have the effect of inhibiting the growth of pancreatic tumors.