顺铂低剂量节律化疗抑制小鼠H22肝癌血管生成观察

目的探讨顺铂低剂量节律（LDM）化疗对小鼠H22肝癌血管生成的影响，观察其抑瘤效果和毒副作用。方法昆明小鼠皮下接种H22细胞，随机分为4组（每组12只），节律组A：顺铂0．6mg／（kg·d）每日腹腔注入，每周5次；节律组B：顺铂1mg／（kg·d）隔日腹腔注入，每周3次；对照组：生理盐水0．2mL每日腹腔注入，每周5次，持续2周；最大耐受剂量（MTD）组：顺铂9mg／（kg·d）一次腹腔注入。每隔2d测量小鼠体质量及肿瘤直径。接种后第15天处死小鼠称瘤质量，行组织学观察，免疫组化法检测肿瘤内微血管密度（MVD）、血管内皮生长因子（VEGF）、基质金属蛋白酶2（MMP-2）和增殖细胞核抗原（PCNA）的表达。结果与MTD组相比较，节律组A、节律组B肿瘤生长缓慢，无明显的体质量减小。节律组A、节律组B、MTD组的抑瘤率分别为66．78％、55．56％、39．44％。节律组A、节律组B肿瘤MVD、VEGF、MMP-2表达较对照组、MTD组显著减少（F＝9．56、9．38、10．17，q=3．56～6．18，P〈0．05）；PCNA指数与对照组比较差异无显著性（F=11．95，q=0．87，P〉0．05）；MTD组PCNA指数较节律组、对照组明显降低，差异有显著性（q=6．18、6．10，P〈0．01）。节律组A、节律组B瘤组织可见大量的细胞变性坏死，对照组和MTD组少见。结论顺铂LDM化疗可显著抑制小鼠H22肿瘤的生长及血管生成，化疗效果好且毒性低；其抗血管生成作用可能与肿瘤内VEGF、MMP-2表达下调有关。

OBSERVATION OF ANTI-ANGIOGENIC EFFECT OF LOW-DOSE METRONOMIC CISPLATIN ON LIVER H22 CELL CARCINOMA GROWTH IN MICE

Objective To observe the anti-angiogenic effect of low-dose metronomic （LDM） cisplatin chemotherapy on growth of liver cell carcinoma H22 in mice. Methods Forty-eight Kunming mice were subcutaneously implanted with cells of liver carcinoma H22, which were evenly divided into four groups： LDM group A, cisplatin （0.6 mg · kg^-1 · d^-1）, once a day, five times a week; LDM group B, cisplatin （1 mg · kg^-1 · d^-1）, once every other day; maximum tolerated dose （MTD）; cisplatin （9 mg · kg^-2 · d^-2） single dose; control group; normal saline （0.2 mL） ,once a day, five times per week for two weeks, the drug was administered intraperitoneally. The weight of the mice and tumor diameter were measured every three days. The tumors were then weighed on day 15 when the mice were killed. Tumor micro-vessel density （MVD）, the expression of vascular endothelial growth factor （VEGF）, matrix metalloproteinase-2 （MMP-2） and the proliferating cell nuclear antigen （PCNA） were detected by immunohistochemical staining. Results Delay of tumor growth without apparent body weight loss was noticed in the mice of LDM groups A and B, compared with those of MTD group. The cancer suppressive rate of LDM groups A and B, and MTD group were 66.78%, 55. 56%, 39. 44%, respectively. Expression of VEGF and MMP-2 and MVD were significantly lower in the mice in LDM groups A and B than those of MTD group and control group （F=9. 56,9. 38,10. 17;q=3.56-6.18;P〈0.05）, while the differences of PCNA between LDM groups and control group were not significant （F=11. 95,q=0.87 ,P〉0.05）, the PCNA index in MTD group was lower than that in control group and LDM groups （q=6.18,6.10;P〈0.01）. Conclusion Tumor growth and angiogenesis are significantly inhibited in mice received LDM treatment. The effect of anti-angiogenesis may be correlated with the low expression of VEGF and MMP-2 in the tumors.