Effect Of Standard Chemotherapy With Sequential Low-dose Single-agent Chemotherapy On NSCLC And On Cellular Immunity

OBJECTIVE:To investigate the efficacy of standard chemotherapy with sequentiallow-dose single-agent chemotherapy(sequential chemotherapy)in the treatment of Lewis lung cancer xenografts in mice and its effect on cellular immune function intumor-bearing mice.METHODS:A Lewis lung cancer(LLC)mouse model was established and randomlydivided into 3 groups.The first group(standard chemotherapy group)was given 3 cycles of standard dose of TP(paclitaxel plus cisplatin)regimen;the second group(sequential chemotherapy group):Two cycles of standard TP regimen chemotherapy followed bylow-dose single-agent(low-dose paclitaxel)chemotherapy;the third group(controlgroup):only saline was given intraperitoneally.During the treatment,the tumor volume and weight were measured every 1 day,and the life status of LLC-bearing mice wasobserved.The tumor-bearing mice were sacrificed after chemotherapy.CD4~+and CD8~+T cells in peripheral blood,spleen,and tumor tissues were detected by flow cytometry,as well as the proportion of CD4~+CD25~+Fox P3~+regulatory T cells(regulatory T cell,Treg)in the spleen and tumor tissues.RESULTS:1.The rate of tumor formation in LLC mice:37 of the 40 LLC mice weretumorigenic and the tumor-inoculation rate was 92.5%.On the 12th day after inoculation,chemotherapy was performed when the tumor volume was 100-200 mm3.2.Chemotherapy efficacy:Compared with the control group,sequential chemotherapy group and standard chemotherapy group significantly inhibited tumor growth intumor-bearing mice(p=0.035,0.027),while sequential chemotherapy and standard chemotherapy group had smaller tumor-bearing tumors.There was no significant difference in the inhibition of tumor growth in mice(p>0.05).3.Effect of sequentialchemotherapy on cellular immune function in tumor-bearing mice:1CD4+,CD8+T cell ratio,and CD4/CD8 value:Peripheral blood,spleen and tumor tissue in sequentialchemotherapy group compared with control groupConclusion:Sequential chemotherapy not only has the effect of inhibiting tumor growth similar to that of standard chemotherapy,but also can reverse the tumorimmunosuppressive microenvironment,but the standard chemotherapy can not reverse the tumor immune suppression microenvironment.