重组人血管内皮抑制素注射液联合冷冻消融治疗肺腺癌A549移植瘤的实验研究

Endostar combined with cryoablation for subcutaneous xenografted tumor model of lung adenocarcinoma cell line A549 in BALB/c nude mice: an experimental study

目的探讨重组人血管内皮抑素注射液(商品名:恩度)联合冷冻消融对肺腺癌A549移植瘤的抑制作用及机制。方法建立肺腺癌A549裸鼠皮下移植瘤模型24只,待肿瘤最大直径达1 cm时,随机分为对照组、血管内皮抑素组、冷冻消融组和血管内皮抑素联合冷冻消融组(联合治疗组)。治疗后第21天处死裸鼠,取肿瘤组织,测量肿瘤体积,采用末端标记法(TUNEL)原位检测周边冷冻损伤区带细胞凋亡,免疫组化SP法检测肿瘤组织微血管密度(MVD)、血管内皮生长因子(VEGF)表达水平。结果治疗后第21天,对照组、血管内皮抑素组、冷冻消融组和联合治疗组的肿瘤生长速率分别为236.68%±51.23%、220.02%±30.61%、159.46%±29.33%和103.34%±25.50%,组间差异有统计学意义(P<0.01);肿瘤细胞凋亡率分别为21.67%±2.34%、22.17%±1.47%、38.33%±1.37%和49.17%±1.72%,组间差异有统计学意义(P<0.01)。联合治疗组的MVD、VEGF表达水平均明显低于其他各组(P<0.01)。MVD与VEGF之间呈正相关关系(r=0.925,P<0.01)。结论血管内皮抑素可明显提高冷冻消融对肺腺癌A549移植瘤的抑制效果,其机制可能与血管内皮抑素通过下调VEGF表达水平,从而抑制肿瘤新生血管形成,协同冷冻消融促进肿瘤细胞凋亡有关。

Objective To investigate the inhibitory effect of Endostar combined with cryoablation on lung adenocarcinoma cell line A549 in BALB/c nude mice, and to discuss its interaction mechanisms. Methods The lung adenocarcinoma A549 model in BALB/c nude mice were established. When the largest diameter of tumor reached 1.0 cm, a total of 24 mice were randomly and equally divided into 4 groups： control group, Endostar group, cryoablation group and cryoablation plus Endostar group. The largest diameter and the vertical diameter of the tumors were measured at different points of time after treatment. At the 21st day, the mice were sacrificed and the tumors were removed and the rate of tumor cell apoptosis, the microvessel density （MVD） and the expression level of vascular endothelial growth factor （VEGF） were determined by using immunohistochemistry method. The results were statistically analyzed. Results The tumor growth velocity of the control group, Endostar group, cryoablation group and cryoablation plus Endostar group was （236.68 ± 51.23）%, （220.02 ± 30.61）% , （159.46 ± 29.33）% and （103.34 ± 25.50）%, respectively （P 〈 0.01）. The rate of apoptosis of the four groups was （21.67 ± 2.34）%, （22.17 ± 1.47）%, （38.33 ± 1.37）% and （49.17 ± 1.72）%, respectively （P 〈 0.01）. The MVD and the expression levels of VEGF of the cryoablation plus Endostar group were significantly lower than those of the other three groups （P 〈 0.01 ）. Statistical analysis revealed that a positive correlation existed between the express of VEGF and MVD. Conclusion Endostar can obviously enhance the therapeutic efficacy of cryoablation on lung adenocarcinoma A549 in BALB/c nude mice. The underlying mechanisms may be the Endostar-inhibited angiogenesis through down-regulating the expression of VEGF, and the cooperative effect of Endostar and cryoablation on the promotion of tumor cell apoptosis.