摘要
目的建立基于临床肿瘤标本的胃癌转移模型,为胃癌的转移研究提供个体化动物模型。方法将胃癌新鲜的手术标本移植到裸鼠皮下,建立胃癌患者异种移植(patient-derived xenograft,PDX)模型。进一步通过手术将皮下瘤组织原位移植到裸鼠胃部肌层,连续观察裸鼠的体征状态,通过近红外荧光活体成像技术检测肿瘤转移的发生。解剖荷瘤小鼠,将肺部转移灶进一步移植裸鼠皮下获得实体瘤。HE染色观察原发瘤与转移瘤的结构特征,(short tandem repeat) STR分析原发瘤和转移瘤的遗传特性。PCR-Array分析转移瘤和原发瘤中转移相关基因的表达。结果成功建立胃癌PDX模型,移植瘤组织结构与患者保持基本一致;通过胃部原位移植发现编号C19751的小鼠发生肺和肝的转移。其中肺转移灶皮下移植后获得了实体瘤,STR分析显示原发瘤保持了与肺转移瘤一致的遗传特征。PCR-Array结果显示,与原发瘤相比,转移瘤中CXCL12,IGF1和MMP2基因表达均显著上调。结论利用临床肿瘤标本成功建立胃癌转移模型,为胃癌转移研究提供了良好的个体化模型。
Objective To establish a mouse model of gastric cancer metastasis derived from clinical tumor specimens, and to provide individualized animal models for the metastasis of gastric cancer. Methods A patient-derived xenograft(PDX) model was established by subcutaneous transplantation of fresh clinical gastric cancer specimens into nude mice. Then, the tumor tissue from the PDX model was transplanted into the muscle layer of mouse stomach. The physical status of these nude mice was observed continuously. The occurrence of tumor metastasis was detected by near-infrared fluorescence(NIRF) optical imaging in vivo. After dissecting the tumor-bearing mice, lung metastatic lesions were further subcutaneously transplanted into nude mice to obtain tumors. The histopathological structures of the primary and metastatic tumors were observed by HE staining, and the genetic characteristics were analyzed using STR tests. Furthermore, the expression of metastasis-related genes was detected by PCR-Array analysis. Results A PDX model of gastric cancer is successfully established, and the histopathological characteristics of tumors in the nude mice were basically consistent with those of the patients. Metastatic lesions in the lung and liver were found in the mouse No.C19751 following orthotopic gastric transplantation. Apparent tumors were formed after subcutaneous transplantation of lung metastatic lesions, and STR analysis showed that the primary tumors well maintained the genetic characteristics of the lung metastatic tumors. The PCR-Array result demonstrated that the expressions of CXCL12, IGF1 and MMP2 in metastatic tumors were significantly upregulated compared with that in the primary tumors. Conclusions A PDX metastasis model of gastric cancer is successfully established in nude mice by xenografting clinical tumor specimens, providing an appropriate individualized metastasis model for research on gastric cancer.
引文
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