VX2移植性兔直肠癌淋巴结转移动物模型的建立及其生物学特性

背景与目的：直肠癌淋巴结转移模型是研究肿瘤发生、发展、转移及抗肿瘤治疗的工具，但较大型动物模型鲜见报道。该研究旨在建立可行性强、重复率高的VX2移植性兔直肠癌淋巴结转移模型。方法：采用原位移植方法，将切好的小瘤块置入穿刺针内，并使用穿刺针将小瘤块推入到新西兰大白兔的直肠壁内。共制作模型20只。每周使用MR扫描2只实验兔，MR上观察肿瘤生长情况及肠周淋巴结个数，使用MR后处理软件测量实验兔的直肠壁肿瘤体积，扫描完成后进行详细解剖，切除直肠壁上肿瘤及肠周淋巴结，进行标本固定及HE染色，并探讨肿瘤体积与生长时间及转移淋巴结个数的关系。结果：成功制作模型13只，成功率为65%。于第4周开始在MR上可观察到局限于直肠壁肿块。随着时间增长，肿瘤体积不断增大，且不同时期(生长周数)肿瘤体积差异有统计学意义(F=52.865，P<0.05)；进一步分析得出，肿瘤的平均体积与生长周数呈正线性相关(r=0.910)，差异有统计学意义(P<0.05)。当肿瘤体积大于9 cm3时，实验兔开始出现转移性淋巴结，第9周开始转移淋巴结个数明显增多。统计分析得出肿瘤体积越大，转移性淋巴结个数就越多(F=92.531， P<0.05)，且两者呈线性相关(r=0.945)，差异有统计学意义(P<0.05)。结论：本实验将组织学完整的VX2移植瘤组织块原位种植到新西兰大白兔直肠内，成功建立了VX2移植性兔直肠癌的淋巴结转移模型。本模型对于研究直肠癌的局部生长、浸润机制、淋巴结转移灶及生物学特性均有一定价值。

Lymph node metastatic models of VX2 tumor in New Zealand white rabbits and their biological characteristics

Background and purpose:The lymph node metastatic model of rectal tumor is a useful tool for the research on tumor occurrence, development, metastasis and antineoplastic therapy. There are few reports about establishment of larger animal model. This study aimed to establish feasible and reproducible lymph node metastatic models of VX2 tumor in rabbits.Methods:The VX2 tumor tissue was put into the puncture needle. The VX2 tumor tissue in the needle was orthotopically transplanted into the rectal wall of the New Zealand white rabbits successfully. Twenty New Zealand white rabbits were transplanted. Two experimental rabbits were scanned by MR weekly. Tumor growth curve and lymph node numbers were observed on MR. Experimental rabbit tumor volumes were measured by MR post-processing software. The rectal tumor and surrounding lymph nodes were resected, and the specimens were ifxed. The sections were stained with HE. We explored the relationship between tumor volume and growth time, the number of metastatic lymph nodes and tumor volume, respectively.Results:Thirteen models were successfully established with a rate of 65%. Tumors limited in the rectal wall were observed on the fourth week. Tumor size increased over time. There was significant difference in the tumor volume between different periods (growth cycle number) (F=52.865,P<0.05). There was a signiifcantly positive correlation between tumor volume and the growth cycle number (r=0.910,P<0.05). The metastatic lymph nodes could be observed when VT>9 cm3. The number of metastatic lymph node increased obviously from the ninth week. The more tumor volume, the greater the number of metastatic lymph nodes was observed (F=92.531,P<0.05). There was a signiifcantly positive correlation between the number of metastatic lymph nodes and the tumor volume (r=0.945,P<0.05).Conclusion:Metastatic lymph node models of VX2 tumor in New Zealand white rabbits were established successfully. This model has some value in the research on local growth, invasion mechanism, lymph node metastasis and biological characteristics of rectal cancer.