人脑肿瘤组织块裸小鼠原位移植方法研究及移植瘤的亲本特征分析

Orthotopic transplantation of human brain tumor tissues in nude mice and analysis of the parental characteristics of the xenografts

目的用肿瘤组织块直接接种法建立人脑肿瘤裸小鼠原位移植模型，通过分析移植瘤的生物学特征来证明本操作方法的可行性。方法取人肺腺癌脑转移瘤的新鲜组织或人脑多形性胶质母细胞瘤（GBM）裸小鼠皮下移植瘤组织，剪成小块，置入专用套管针，通过事先钻好的颅骨孔．徒手推入裸小鼠右尾状核。观察致瘤率、移植瘤的组织细胞形态、相关标志物、MRI图像特征和荷瘤鼠生存期。结果肺腺癌脑转移瘤和GBM组织在鼠与鼠之间分别传了6代和13代，荷瘤鼠生存期分别为（38．0±0．9）d和（19．0±1．3）d。肺腺癌脑转移瘤移植瘤不向周围正常鼠脑组织侵袭，分泌酸性粘液及表达癌胚抗原等生物学特征与其亲本肿瘤一致：而GBM移植瘤具有向周围正常鼠脑组织高度侵袭及高表达表皮生长因子受体的生物学特征也与其亲本肿瘤一致。结论肿瘤组织块直接注入裸小鼠脑内建立的实验动物模型比肿瘤细胞悬液接种方法相对简易，且移植瘤能更好地保持亲本肿瘤的特征。此法可进一步在各种脑肿瘤动物原位移植实验中推广应用。

Objective To establish a method for direct orthotopic transplantation of human brain tumors into mouse brain and assess the parental characteristics of the xenografls. Methods Fresh tissues of human brain metastasis of lung adenocarcinoma and glioblastoma tissues subcutaneously implanted in nude mice were harvested and minced into pieces. A special trochar was used to inject the tissue pieces into the right caudate nuclei of nude mice through the burr hole in the mouse skull. The efficiency of tumorigenicity, survival time of tumor-bearing mice, histopathological features, expressions of tumor markers in the xenografts and MRI findings were observed. Results The metastatic lung adenocarcinoma and glioma xenografts were passaged for 6 and 13 generations in nude mice, and the average survival time of the tumor-bearing mice was 38.0±0.9 days and 19.0± 1.3 days, respectively. The metastatic xenografts were characterized by expressions of CEA and acid mucin without invasiveness to the normal recipient brain tissue, which were consistent with the features of the parental metastatic tumor. The glioma xenografts exhibited deep invasiveness to the normal recipient brain tissue and high expression of EGFR, which were identical to the characteristics of the parental tumor. Conclusion Compared with stereotactic cell suspension injection, direct tumor tissue graft injection requires simple procedures and well maintains the characteristics of the parental tumor tissue in the xenograft in nude mice. This method well suits the purposes of establishing orthotopic xenotransplantation models of brain tumors in nude mice.