人葡萄膜黑色素瘤小鼠肝内种植模型生长行为研究

Establishment of a nude mouse model of intrahepatic implantation of human uveal melanoma and studies on its growth behavior

目的:采用肝内注射人眼葡萄膜恶性黑色素瘤株(MUM2B细胞)方法制备该肿瘤的小鼠肝内种植模型,研究肿瘤在其体内的生物学行为。方法:选用BALB/C-nu裸鼠,将5×104个MUM2B细胞注入裸鼠肝脏包膜下。连续观察6周,每周随机处死3只裸鼠以观察成瘤率及侵袭率。采集裸鼠的荷瘤肝脏、心脏、脾脏、肺脏、肾脏、胃和肠等组织器官,常规石蜡切片,HE染色后镜检肿瘤在肝脏内的生长行为及其向其他脏器侵袭和转移的情况。结果:该模型的成瘤率可达83.3%。接种后的前4周,肿瘤在肝脏内浸润性生长,未侵犯周围脏器;接种后第5周,肿瘤开始侵袭肾脏、脾脏、胃和十二指肠的包膜,并可突破胃及肠道的包膜,在其浆膜层中侵袭生长;接种后第6周,肿瘤对肾脏、脾脏、十二指肠和胃的侵袭加剧。肿瘤细胞可侵入裸鼠十二指肠的肌层内生长,亦可侵入裸鼠胃肌层及胃黏膜下层,甚至向胃黏膜肌层内侵袭生长;接种后第6周,肿瘤开始向裸鼠肺脏转移,所有受检裸鼠的肺门组织及肺实质内均可查见转移性瘤灶,转移率达100%;除肺脏外,其余脏器内均未查见转移性瘤灶,提示肺脏是该肝内种植瘤的主要转移靶器官。此外,荷瘤2周后,裸鼠脾脏红髓增生明显,髓内可见大量巨核细胞及髓系来源的粒细胞,呈现白血病样反应;荷瘤4周后,脾脏内星空样现象明显,巨噬细胞活跃,提示裸鼠脾脏组织学改变与荷瘤生长状态密切相关。结论:裸鼠肝内注射MUM2B细胞能够建立起稳定的人葡萄膜黑色素瘤小鼠肝内种植模型。种植的肿瘤细胞在裸鼠肝脏内呈浸润性生长,侵袭包括胃、十二指肠、脾脏及肾脏在内的多个器官,并可远端转移至肺脏。

OBJECTIVE： To establish a nude mouse model Of intrahepatic implantation of human uveal melanoma,and monitor the biological behavior of the tumor. METHODS： Experimental xenograft animal model of human uveal melanoma was established via injecting 5 × 10^4 MUM2B cells under peplos of BLAB/C-nu mouse livers. Animals were monitored for 6 weeks. Three animals were randomly picked out to be sacrificed to record the biological behavior of tumors every week. Organs, such as tumor, heart, liver, spleen, lung, kidney, stomach and duodenum, were also collected for histological survey at each check point. The tumor formation rate, invasion rate and metastasis rate were calculated subsequently. RESULTS： The tumor formation rate in this study reached at least 83.3 %. During the four weeks after tumor implantation, tumor cells mainly grew in the liver of mouse,no invasion was observed in any mice model. At the fifth week,tumor began to invade the peplos of lateral normal organs, such as spleen, kidney, stomach and duodenum. Although tumor cells broke through the peplos of stomach and duodenum and invade their placenta percreta, no metastasis was observed at this time point. At the sixth week,tumor cells continuously invaded the organs mentioned above. Large amount of tumor ceils invaded the muscular layer of duodenum and stomach. Tumor cells also could be detected in the submucous lamina and thelamina muscularis mucosae of stomach. At the same time,metastases were observed in hilar tissues adjacent to the lung and the lung parenchyma, the tumor metastasis rate was 100%. Metastasis nodes were only detected in mice lungs, which indicated that lung was the main target organ for metastasis. Two weeks after tumor implantation, hyperplasia of the red pulp with a concomitant decrease in white pulp area was observed in mice spleens. The red pulp was laden with granulocytes,a variety of myeloid lineage cells,and very prominent megakaryocytes,which was called as leukemoid reaction. Four weeks after tumor implantation, starry phenomenon was observed in mice spleens, which indicated the activation of macro phages. It indicated that histological changes in spleen correlated with tumor growth. CONCLUSIONS： The nude mouse model of intrahepatic implantation of human uveal melanoma can be established by injecting MUM2B cells under the peplos of BALB/C-nu mouse liver. The implanted tumor cells grew in liver in an aggressive manner and invaded many organs including stomach,duodenum,spleen and kidney. The tumor cells also metastasized to lung in advanced stage.