兔VX2瘤转移性肺癌动物模型的建立和生物学特性研究

Hematogenous pulmonary metastases of VX2 carcinoma in rabbit: establishing model and observing its biological speciality

目的 建立兔VX2瘤转移性肺癌动物模型 ,并研究其生物学特性。方法 实验动物为新西兰大白兔 ,瘤种采用动物自身接种传代保存。取预先接种荷瘤兔 1只 ,无菌下摘取瘤组织块 ,用Ⅳ型胶原酶解离释放细胞 ,经细胞培养后制成单细胞悬液 2 4ml(10 8/ml)。 (1)建立动物模型 :实验动物共 2 0只 ,分 2组 ,A组 (14只 )每只兔经耳缘静脉接种 1 5ml单细胞悬液 ,B组 (6只 )每只兔接种0 5ml。第 2 8天行多排螺旋CT(MSCT)扫描 ,扫描后 1周全麻下剖胸取肺观察肿瘤生长情况 ,所有兔均做病理学检查。 (2 )生物学特性研究 :实验动物为新西兰大白兔 (10只 ) ,每只兔经耳缘静脉接种1 5ml单细胞悬液 ,接种后第 14、2 1、2 8天各抽取 1只兔剖胸取肺观察肿瘤生长情况 ,并做组织学检查 ,第 3 2天另外存活兔全麻下取肺组织做病理切片检查 (HE染色 )。结果 (1)动物模型 :19只兔接种成功 ,另 1只第 2 1天时死于大叶性肺炎 ,接种成功率为 95 %。新鲜大体标本显示肿瘤呈弥漫性分布 ,大小不等 ,呈结节样 ,部分病灶融合 ,表面呈鱼肉样。MSCT扫描示肺内结节清楚 ,并可见肺间质纹理增粗。A组与B组石蜡切片最大结节比较差异具有显著性意义 (t=2 885 ,P <0 0 1)。 (2 )生物学特性研究 :10只兔全部接种成功。大体标本显示肿瘤呈弥漫性分?

Objective To establish hematogenous pulmonary metastases of VX2 carcinoma in rabbit experimental model and to observe its biological speciality. Method The first part: 20 New Zealand white rabbits were implanted with VX2 single cell suspensions acquired from a previous tumor bearing rabbit. All the rabbits were randomly divided into 2 groups, 1.5 ml cell suspension was injected into ear vein in group A ( n =14) and 0.5 ml was injected in group B ( n =6), respectively. Multi slices spiral computed tomography (MSCT) was performed to detect tumor nodules on the 28th day after implantation. All the rabbits were sacrificed one week after MSCT scan, and the trachea and lung were removed together for pathological examination. The diameters of the nodules were measured with slide gaud as scheduled .The second part: 1.5 ml VX2 single cell suspension was injected into right ear vein in another 10 New Zealand white rabbits, respectively. One rabbit was randomly sacrificed on the 14th day, 21st day, and 28th day after implantation. The trachea and lung were kept to observe tumor growth. The other 7 rabbits were sacrificed to obtain pathological examination (HE stain) on the 32nd day after implantation as scheduled. Results The first part: VX2 carcinoma was successfully implanted in 19 rabbits, and one rabbit died of lobar pneumonia on the 21st day. The success rate was 95%. The tumor nodules were diffusively distributed on the pulmonary surface in the fresh specimens. Microscopic findings showed the evidences of interstitial spreading, infiltration into arterioles and bronchial wall, and diffusive emphysema as well. MSCT provided signs of diffusive nodules in the parenchyma and irregularly increased lung markings. The two groups had significant difference in tumor nodule diameter. The second part: VX2 carcinoma was successfully implanted in all 10 rabbits. All specimens showed tumor nodules diffusively distributed on the lung surface with rapid increase in diameter and density. Extrapulmonary infiltration occurred as the breeding persisted. Microscopic findings showed the evidences of interstitial spreading, infiltration into arterioles and bronchial wall, and diffusive emphysema as well. Conclusions The pulmonary metastases of VX2 carcinoma had been established successfully. The formation of metastatic nodules is directly related with the number of tumor cells in the circulation. Collagenase Ⅳ would be essential in dissolving the tumor interstitial tissue, and it might be contributive to tumor infiltration. The infection should be prevented in order to simultaneously obtain large number of animal models. VX2 tumor is a malignant neoplasm similar to that in human. The establishment of the tumor model will be conducive for the prevention and treatment of pulmonary metastasis.