The Effect Of Combining FOLFOX4with1-D-methyl Tryptophan On The Cellular Immunity Of Gastric Cancer Bearing615Mice

Objective: To investigate whether Combiningl-D-MT with FOLFOX4is useful toimprove the immune tolerance of gastric cancer bearing615mice.Methods:(1)By using the liMpofectamine12000the eukaryotic expression plasmidpcDNA3.1-IDO and empty vector pcDNA3.1were transfected in a MFC cell line，After screened with G418，the single cell clone was sought out and cultured. Theexpression of IDO was detected by reverse transcription polymerase chainreaction(RT-PCR) and western blot，then we got the new cell line，which can expressIDO steadily.(2)Animal model of gastric cancer bearing615mice were established，whichwere divided into MFC group, empty plasmid group，IDO+normal saline(NS) group，IDO+FOLFOX4group, IDO+1-D-MT group，IDO+1-MT+FOLFOX4group(each group were n二8). We can observe the mice tumor cases, differences of tumorvolume and pathological routine examination。(3)By using lfow cytometry, to analysis Tregs cell and CTL cell ratio change。(4)by using RT-PCR，to analysis FOXP3mRNA and GzmBmRNA expressionchange。Result:(])By RT-PCR and Westrn blot，we can find IDO expressed in the MFC celltrancfected with pcDNA3.1-IDO much higher than the MFC cell and the MFC celltrancfected with pcDNA3.1. (2)Compared with MFC and the empty vector saline group, IDO saline grouphave bulky tumor, fast growth, and the differences were statistically signiifcant (P<0.05); Compared with IDO saline group, FOLFOX4group,1-D-MT group andcombined group were smaller tumor volume，less weight，and the tumor inhibitoryrates were83.47%、81.82%、95.68%respectively，there were significantdifferences between them(P <0.05)， moreover the combined treatment group seemsto be better (P <0.05).But FOLFOX4group and1-D-MT group tumor volumechanges were no significant differences (P>0.05)。(3)HE pathological observation： Cell density were decreased and necrotic areawere decreased of the treatment groups。(4)Treg cell ratio in the1-D-MT+FOLFOX4group and1-D-MT group are lessthan FOLFOX4group (p<0.05)，and1-D-MT+FOLFOX4group reduces moreremarkable than1-D-MT group(p<0.05)； But in contrary，CTL cell ratio obviouselyrise (p<0.05)，and1-D-MT+FOLFOX4group rises more remarkable than1-D-MTgroup (p<0.05)o(5)FOXP3mRNA expression in the1-D-MT+FOLFOX4group and1-D-MTgroup are less than FOLFOX4group (p<0.05)，and1-D-MT+FOLFOX4groupreduces more remarkable than1-D-MT group (p<0.05)； But in contrary,GzmBmRNA expression obviousely rise (p<0.05)，and1-D-MT+FOLFOX4grouprises more remarkable than1-D-MT group (p<0.05)。Conclusion: Combining1-D-MT with FOLFOX4can reduce Treg cell ratio andenhance the lethality of CTL cell to the cancer cell， thus reducing the immuneescape0...