镉、锌制剂联合应用抑制肝细胞癌生长和转移的实验研究

Inhibition of growth and metastasis of Human Hepatocellular carcinoma by Cadmium and Zinc preparation combined treatment in a nude mouse xenograft model

目的研究氯化镉(Cadmium Chloride)和硫酸锌(Zinc Sulfate)对肝细胞癌生长和转移的抑制作用。方法建立人肝细胞癌异位种植转移模型。将荷瘤裸60只鼠随机分成五组,每组12只。种植1周后开始,分别自腹腔一次性注射生理盐水(对照组)、氯化镉(Cd组三个剂量:1.0 mg,2.0 mg,3.0 mgCd/kg)、氯化镉(3.0 mgCd/kg)与硫酸锌联合应用(Zn+Cd)。种植后第8周末处死动物,测量种植处肿瘤重量、体积、观察癌细胞转移及腹水出现情况、透射电镜观察肝细胞超微结构,免疫组织化学法(immunohistochemistry,IHC)检测肝脏及肝癌组织金属硫蛋白(Metallothionein,MT)。结果各组均成瘤,Zn+Cd组、Cd组(3.0 mg,2.0 mg,1.0 mgCd/kg)与对照组相比,裸鼠肿瘤生长差异有显著性意义(P<0.05);腹膜转移率分别为8.3%、9.1%、18.1%、36.4%、100%(P<0.05);透射电镜观察,Cd组与Zn+Cd组相比,线粒体、粗面内质网明显减少,溶酶体、脂滴增多;IHC检测,Zn+Cd组荷瘤裸鼠肝脏组织的MT染色明显加深,肝癌组织MT染色无明显改变。结论镉对肝细胞癌生长和转移有较强的抑制作用;应用镉剂治疗前预用锌,对正常肝组织有保护作用。

Objective To study the effects of Cadmium Choloride and Zinc Sulfate on the growth and metastasis of hepatocellular cacinoma in vivo.Methods A nude mice xenograft model was established by subcutaneously injecting SMMC- 7721 cells,a HHC cell line,in the fight shoulder. Sixty male nude mice were randomized into control,Cd （3.0 mg,2.0 mg, 1.0 mgCd/kg,once.ip,respeetivdy）, Zn ＋ Cd group. After eight weeks tumour weight , volumes,metastasis and aseites, hepaocellular ultrastructures by transmission electron - microscopy, IHC for MT expression were evaluated, respectively. Results Compared with control, turnout growth was significantly inhibited in treatment group and the incidence of peritoneal metastases was significantly inhibited in nude mice treated respectively with Cd（1.0 mg,2.0 mg,3.0 mgCd/kg） and Zn ＋ Cd group（100% ,36.4% ,18.0% ,9.1% and 8.3%） .Transmission electron-microscope showed that the number of mitochondrion and rough endoplasmic reticulum were decreased and the number of lysosome and lipid droplet were increased in Cd group,compared with Zn ＋ Cd group. MT immunochemistry straining of liver showed the stains was stronger in the group pretreated with Zn than control group, which indicated that the MT can be induced by Zinc in norreal tissue but not in hepatic cancer tissue. Conclusion Cd has strong inhibitory effect both on tumour growth and metsstases of human hepatoeellular carcinoma. Pretreatment with Zinc has protective effects on hepatic cells.