靶向HRP/IAA自杀基因系统联合IL-12基因治疗Lewis肺癌的研究

Efficacy of targeted HRP/IAA suicide gene system combined with IL-12 gene in Lewis lung carcinoma

目的:观察人端粒酶逆转录酶(hTERT)启动子驱动辣根过氧化物酶(HRP)/吲哚乙酸(IAA)系统联合白细胞介素-12(IL-12)基因对小鼠Lewis肺癌的疗效。方法:建立Lewis肺癌移植瘤模型,随机分为对照组、HRP组、IL-12组和联合组,分别给予AdCMVGFP、AdhTERTHRP、AdCMVmIL-12单一或联合注射,然后腹腔注射IAA,观察肿瘤生长情况。蛋白质印迹法和ELISA检测瘤组织HRP和IL-12表达;免疫组化检测瘤组织内CD4+、CD8+淋巴细胞浸润情况。结果:与对照组、单一治疗组相比,联合组小鼠肿瘤生长受到显著抑制(联合组vs对照组:P=0.000,9 d;联合组vsHRP组:P=0.005,15 d;联合组vsIL-12组:P=0.046,12 d),生存期显著延长(联合组vs对照组:χ2=9.529,P=0.002;联合组vsHRP组:χ2=9.039,P=0.003;联合组vsIL-12组:χ2=8.595,P=0.003),肿瘤组织广泛坏死,CD4+、CD8+淋巴细胞浸润显著增多。结论:IL-12基因治疗可诱导宿主产生抗肿瘤免疫应答,与靶向HRP/IAA自杀基因系统联合具有协同抗肿瘤作用。

OBJECTIVE：To investigate the antitumor effect of horseradish peroxidase（HRP）/indole-3-acetic acid（IAA） system driven by human telomerase reverse transcriptase（hTERT） promoter in combination with interleukin-12（IL-12） gene in a murine model of Lewis lung carcinoma.METHODS： Murine models of Lewis lung carcinoma were established and randomized into 4 groups： control,HRP group,IL-12 group and combination group,which were treated with AdCMVGFP,AdhTERTHRP and AdCMVmIL-12 alone or in combination followed by IAA administration,respectively.Tumor growth and animal survival was monitored to evaluate the antitumor effect.The expression of HRP and IL-12 was determined using the western blot and enzyme-linked immunosorbant assay,respectively.Lymphocyte infiltration was evaluated by immunohistochemistry.RESULTS： Tumor growth in combination group was significantly inhibited compared with other groups（combination vs control：P=0.000,9 d;combination vs HRP： P=0.005,15 d;combination vs IL-12： P=0.046,12 d）.The survival in combination group was statistically prolonged in comparison to other groups（combination vs control：χ2=9.529,P=0.002;combination vs HRP： χ2=9.039,P=0.003;combination vs IL-12： χ2=8.595,P=0.003）.The combination group showed larger areas of necrosis and more CD4＋ or CD8＋ lymphocyte infiltration than any other group.CONCLUSION： HRP/IAA suicide gene system mediated by hTERT promoter in combination with IL-12 gene is more effective than either single treatment,which can provide a novel therapeutic strategy for lung cancer.