脐血间充质干细胞靶向胃癌移植瘤的实验研究

Experimental study on the tropism of umbilical cord blood mesenchymal stem cells for gastric carcinoma xenografts

目的探讨脐血间充质干细胞靶向胃癌的可能性。方法将胃癌细胞SGC一7901注射到裸鼠腹股沟皮下，建立胃癌裸鼠模型，荷胃癌小鼠随机分为脐血间充质干细胞组与成纤维细胞组，每组5只（n=5）。荧光染料SP—DiI染色人类脐血问充质干细胞及成纤维细胞，分组注射到对侧腹股沟皮下。10d后处死裸鼠，取出肿瘤、注射部位、肝脏、脾脏和肺脏组织，连续切片分别制成冷冻切片和常规HE染色，荧光显微镜下观察冷冻切片中间充质干细胞和成纤维细胞在各组织中的分布。结果脐血问充质干细胞在荷胃癌小鼠肿瘤部位中的荧光面积为（0．0150±O．0079），注射点、肝脏、脾脏和肺脏组织中的荧光面积分别为（0．0043±0．0039）、（0．0010±0．0005）、（0．0015±0．0012）和（0．0014±0．0008），肿瘤部位中的荧光面积与其他部位相比差异有统计学意义（P〈0．01）；成纤维细胞主要集中于注射点位置，在肿瘤组织、肝脏、脾脏和肺脏内均未发现它的存在，在两组裸鼠移植瘤中，脐血间充质干细胞的分布与成纤维细胞相比差异均有统计学意义（P〈0．01）。结论人类脐血间充质干细胞能趋向到胃癌组织中，利用此特性可望将其作为载体应用到胃癌的诊断和治疗中。

Objective To investigate the possibility of human umbilical cord blood mesenchymal stem cells＇ migrating to the gastric carcinoma xenografts. Methods Gastric cancer cells SGC-7901 were injected subcutaneously into one side of the inguinal groove in the hairless mice to establish the animal model. Gastric cancer-bearing mice were divided randomly into two groups and five in each group （n =5）. Then mesenchymal stem cells and the fibroblast HFL-I labeled with fluorescent dye SP-DiI were injected at the opposite side. Ten days later, the mice were put to death, and the gastric carcinoma xenografts, liver, spleen, lung and the tissue of injected point were obtained. Cryosections from frozen tissues were processed for fluorescent microscopy and the distribution of MSC and fibroblasts in different organs were observed. Adjacent sections were stained with HE. Results Human umbilical cord blood mesenchymal stem cells were mainly distributed in gastric carcinoma xenografts （0.0150±0.0079）, but were found only a little in liver （0.0010± 0.0005）, spleen （0.0015±0.0012）, lung （0.0014±0.0008） and injected point （0.0043±0.0039）. Fibroblasts were mainly observed in the tissue of injected point, but none in other tissues （P 〈0.01）. Conclusion Human umbilical cord blood mesenchymal stem cells have the tendency of migrating to tumor sites, suggesting that it can be hopefully used in the diagnosis and treatment of gastric cancer.