竹荪多糖与多西紫杉醇联用抗肺癌效应及机制研究

Effect of docetaxel combined with Dictyophoraindusiata polysaccharides on Lewis lung cancer in mice

目的 探讨竹荪多糖与多西紫杉醇(DOC)在肺癌治疗中的协同效应及机制.方法 40只C57小鼠构建路易斯肺癌(LLC)荷瘤C57小鼠模型,分别采用竹荪多糖组分ZSP1(ZSP1组)、DOC(DOC组)、ZSP1+DCC联用(联用组)及0.9%氯化钠注射液(对照组),每组10只,在建模当天开始腹腔注射治疗,第10、12、15天时检测肿瘤体积,并采用流式细胞术检测小鼠外周血及脾中髓源抑制性细胞(MDSC)的比例.另用Tol样受体素4(TLR4)基因敲除C57小鼠(TLR4KO组)和野生型C57小鼠(WT组)构建LLC荷瘤模型,采用实时荧光定量PCR检测MDSC中IFN-γ、IL-12、CXCL-9和CXCL-2mRNA表达水平,Western blot法检测IL-12蛋白表达水平.结果 与对照组相比,ZSP1组、DOC组和联用组小鼠的肿瘤体积在第10、12、15天均明显为小(均P<0.01);TLR4KO组较WT组小鼠的肿瘤体积在第10、12天均明显为小(均P<0.01);第12、15天联用组小鼠的MDSC比例均明显低于对照组、ZSP1组和DOC组,差异均有统计学意义(均P<0.01);与WT组相比,TLR4KO组IFN-γ、IL-12和CXCL-9mRNA表达水平均明显增加(均P<0.01),IL-12蛋白表达水平有所增加.结论 DOC与竹荪多糖联用抗肿瘤效果优于单用,其作用机制与下调荷瘤小鼠外周血中MDSC比例有关,其作用受体可能为TLR4.竹荪多糖与DOC联用可以上调IL-12的转录水平和表达水平.

Objective To investigate the antitumor effect and mechanism of Dictyophoraindusiata polysaccharides and docetaxel(DOC)on Lewis lung cancer(LLC)in mice.Methods LLC cells were inoculated subcutaneously in C57 mice,and the tumor-bearing mice were treated with ZSP1,DOC,ZSP1 plus DOC or 0.9%sodium chloride injection(control group).The tumor size was measured;the percentage of myeloid derived suppressor cell(MDSC)in peripheral blood and spleen was detected by flow cytometry(FCM).TLR4R-knocked out C57 mice(TLR4R KO mice)bearing LLC were used to study the antitumor mechanism of ZSP1 and DOC.Real-time fluorescence PCR and Western blot were used to detect the cytokine transcriptional level and express level of IL-12 in tumor-bearing mice,respectively.Results Compared to control group,the tumor size in ZSP1,DOC and ZSP1+DOC groups was significantly decreased at d10,d12 and d15(all P<0.01).Compare to wild type(WT)mice the tumor size in TLR4KO group was significantly reduced at d10 and d12(all P<0.01).The percentage of MDSC in ZSP1+DOC group was significantly lower than that in control group、ZSP1 group and DOC group at d12 and d15(all P<0.01).In TLR4 KO mice,the mRNA expression of IFN-γ,IL-12 and CXCL9 was increased and the protein expression of IL-12 was also increased compared to those in wild type mice.Conclusion The combination use of Dictyophoraindusiata polysaccharides and DOC promotes the antitumor effect on LLC in mice,which is associated with decreased peripheral MDSC percentage and increased IL-12 expression in tumor-bearing mice;and the TLR4 may be the effect target.