Cytokine-induced Killer Cells Targeted Killing Experimental Study Of Gastric Cancer

Objective:To investigate the possibility of the cytokine-induced killer cells targeting gastric cancer and the lethal effect to gastric cancer,including the molecule mechanism involved in the process.Methods:Culture the gastric cancer cells SGC-7901 and the cytokine-induced killer cells in vitro,Gastric cancer cells SGC-7901 were injected subcutaneously into the inguina of nude mice,gastric cancer-nude mice model was established.Gastric cancer-bearing mice were divided randomly into cytokine-induced killer cells group and fibroblasts group,five in each group,(n=5),Marked the cytokine-induced killer cells and the fibroblasts HFL-I with fluorescence dye SP-Dil,they were injected subcutaneously into the opposite side of inguina of implantation neoplasma.Gastric cancer-bearing mice were killed after ten days,Took out of the tumor tissue,the injection situs,liver,spleen and lung.Adjacent sections were differently produced frozen sections and stained with H&E,and observed the cytokine-induced killer cells distribution in the gastric cancer-bearing mice in vivo under fluorescence microscope.Using fibroblast as the control.Established gastric cancer-nude mice model by the same way,these animals were divided randomly into the cytokine-induced killer cells group and fibroblasts control group,six in each group,(n=6),the cytokine-induced killer cells were injected subcutaneously into the opposite side of inguina of implantation neoplasma;fibroblasts were injected to the control group.Measured the long and short diameter of the tumor,to obtain the tumor's approximation volumes and the ratio of curbing carcinoma.Executed the mice in the fourteenth day,sliced the tumor tissue into pathological section,observed the necrosis areas in the tumors.Take the cytokine-induced killer cells of the different cultured days(the 0,seven,fourteen days),the expression of the activated form acceptor NKG2D in the cytokine-induced killer cells was determined by RT-PCR method.The expression of MICA in gastric cancer cells 7901,803,colon carcinoma cell line HT-29 and fibroblast was determined by RT-PCR method.Results:(1) The cytokine_induced killer cells marked with the dye were concentrated mainly at the tumor location in the gastric cancer-bearing mice in vivo after ten days,the distribution of the cytokincinduced killer cells in the tumor has significant difference compared with that in the injection situs,liver,spleen and lung(P<0.01);the fibroblast were altogether not founded in the tumor,liver,spleen and lung in the fibroblast team,but it concentrated mainly in the injection situs,the distribution of the cytokine-induced killer cells and the fibroblast in the tumor of the two group mice has significant difference(P<0.01).(2) From the tumor volume and the ratio of curbing carcinoma,the therapeutic efficacy in the cytokine.induced killer cells group was obviously better than fibroblasts control group(P<0.01).(3) The results of RT-PCR exhibited that the expression of the activated form acceptor NKG2D were all founded in the cytokine-induced killer cells in different cultured days.(4) The results of RT-PCR exhibited that the expression of MICA were all founded in gastric cancer cells 790,803,colon carcinoma cell line HT-29,but not founded in fibroblast.Conclusion:(1) The cytokine-induced killer cells trend automatically gastric cancer,it can target and kill gastric cancer tissue.(2) The cytokine-induced killer cells represent target quality to gastric cancer to draw assistance from the interaction between the activated form acceptor NKG2D and its ligand MICA.