三氧化二砷联合维生素C抑制耐药性肺腺癌裸鼠移植瘤生长机制的研究

Anti-tumor Mechanism of Combining Arsenic Trioxide with Vitamin C on Subcutaneously Transplanted Tumor of Drug Resistant Human Lung Tumors in Nude Mice

目的:探索三氧化二砷(As2O3)联合维生素C(Vit C)对人耐药性肺腺癌裸鼠移植瘤抑制作用及其可能机制。方法:建立裸鼠人耐药性肺腺癌移植瘤模型,随机分为空白对照组,维生素C组(Vit C,250 mg.kg-1),As2O31组(1.5 mg.kg-1),As2 O3 2组(As2 O3 3 mg.kg-1),As2 O3联合Vit C组(As2 O3,1.5 mg.kg-1+VitC 250 mg.kg-1),ip 2周,观察并记录各组裸鼠移植瘤的生长情况及肿瘤体积和裸鼠体重的变化,计算肿瘤生长抑制率,用药2周后,取瘤组织进行病理学检查。用逆转录聚合酶链反应(RT-PCR)和蛋白印迹法(Western blot)检测移植瘤内生存素(Survivin)与血管内皮生长因子(VEGF)的表达情况。结果:Vit C组,As2O3 1,2组,As2O3联合Vit C组的抑瘤率分别为:3.42%,42.3%,66.25%,79.93%。与对照组相比,As2 O3各组和As2 O3+Vit C组治疗后肿瘤体积减少,瘤质量减轻,差异均有显著性(P<0.O1);与As2 O3单独用药组比较,As2 O3+Vit C联合用药组肿瘤体积,瘤质量明显减少(P<0.O1),抑瘤率明显增高;而Vit C组治疗后肿瘤体积及瘤质量没有明显减少。病理检查显示各As2O3组、As2O3+Vit C组治疗后可见肿瘤坏死增多。RT-PCR及Western,blot结果显示:联合组与As2O3组、Vit C组比较Survivin、VEGF条带强度显著减小。结论:As2O3与Vit C联合用药比As2O3单独应用抑制耐药性肺癌移植瘤生长的作用更强,二者具有协同抗肿瘤作用,其作用机制可能与下调Survivin及VEGF的表达有关。两者联用有望成为低毒高效的化疗组合。

Objective：To study the effect and mechanism of arsenic trioxide（As2O3） with vitamin C（Vit C） on the subcutaneously transplanted tumor of drug resistant human lung tumors in nude mice.Method： The subcutaneously transplanted tumor models of drug resistant human lung tumors in nude mice were established and then were divided at random into 5 groups： NS,Vit C（250 mg·kg-1）,As2O3（1.5,3.0 mg·kg-1）,and combining As2O3 with Vit C.They were injected intraperitoneally for two weeks.The weight of mice and volume of tumor pre-and post-administration were measured.All mice were killed after administration,and measured the mass of tumor and calculated the tumor inhibition.Tumor tissue was examined by pathological method.RT-PCR and Western blot were used to detect the vascular endothelial growth factor and survivin.Result： The tumor inhibitory rate of Vit C,As2O3（1.5,3.0 mg·kg-1）,and combining As2O3 with Vit C were 3.42%,42.3%,66.25%,79.93% accordingly,and the volume,mass of tumor were decreased after treatment,in contrast to the saline group,the differences were significant（P0.01）.The tumor mass and volume were decreased in the test groups,more markedly in the combined drug group than single-drug groups.Moderate necrosis was found in tumor tissues.The expression of survivin mRNA and VEGF mRNA in the combination group was markedly lower than those in the other groups.The result of Western blot was also support RT-PCR＇s.Conclusion： Combined As2O3 and Vit C has stronger inhibition effect on tumor growth than single use of each drug,with a synergic anticancer effect on transplanted lung cancer in nude mice.Possible mechanism is related to the down-regulation of the expression of survivin and VEGF.Application of vitamin C and As2O3 might be a chemotherapy combination with low toxicity and efficient.