持续小剂量化疗对人肺腺癌A549细胞裸鼠移植瘤VEGF-C及其受体Flt-4表达的影响

Influence of low-dose metronomic chemotherapy on expression of VEGF-C and its receptor Flt-4 in lung adenocarcinoma A549 cell xenografts in nude mice

目的探讨持续小剂量(LDM)化疗对肺腺癌A549细胞荷瘤裸鼠肿瘤组织中血管内皮生长因子-C(VEGF-C)/fms-样酪氨酸激酶-4(Flt-4)轴的影响及其机制。方法将人肺腺癌A549细胞接种于18只裸鼠皮下,建立荷瘤动物模型,以随机数字表法将其分为最大耐受剂量(MTD)组(CTX 100mg.kg-1腹腔注射,隔日1次,连续3次;n=6)、LDM组(CTX 20mg.kg-1.d-1腹腔注射,n=6)和对照组(0.1mL生理盐水腹腔注射,1次/d;n=6)。治疗21d后脱颈处死裸鼠,取皮下肿瘤组织,采用免疫组织化学链霉素抗生物素蛋白-过氧化物酶(SP)法及逆转录聚合酶链反应(RT-PCR)分别检测肿瘤组织中VEGF-C、Flt-4的蛋白及mRNA表达。结果 LDM组裸鼠肿瘤组织VEGF-C、Flt-4蛋白及mRNA的表达水平均显著低于MTD组和对照组(P<0.05)。结论 LDM化疗可能通过降低肿瘤组织VEGF-C、Flt-4的表达而减少肺腺癌A549荷瘤裸鼠肿瘤的淋巴转移。

Objective To explore the effects and mechanism of low-dose metronomic（LDM） chemotherapy on VEGF-C/Flt-4 axis in lung adenocarcinoma A549 cell xenografts in nude mice.Methods The human lung adenocarcinoma A549 cells were seeded in 18 nude mice to establish tumor-bearing animal models.They were divided into maximum tolerated dose（MTD） group（CTX 100 mg·kg-1 intraperitoneal injection every other day,3 consecutive times;n=6）,LDM group（CTX 20 mg·kg-1·d-1 intraperito-neal injection,n=6） and control group（0.1 mL saline intraperitoneal injection once daily,n=6） according to a random number table.The nude mice were sacrificed by neck luxation after 21 days of treatment,and subcutaneous tumor tissue were subjected to streptavidin-perosidase（SP） immunohistochemistry and reverse transcriptase-polymerase chain reaction（RT-PCR） for VEGF-C,Flt-4 protein and mRNA expression detection,respectively.Results VEGF-C,Flt-4 protein and mRNA expression level in tumor tissue of nude mice in LDM group were significantly lower than those in MTD group and control group（P0.05）.Conclusion LDM chemotherapy may reduce lymphatic metastasis of lung adenocarcinoma A549 cell xenografts in nude mice through decreasing VEGF-C,Flt-4 expression in tumor tissue.