目的 观察人牙髓间充质干细胞（HDP-MSCs）对免疫缺陷小鼠的致瘤性作用。方法 雌性NOG小鼠随机分为4组：对照组和HDP-MSCs低、中、高剂量（2×10⁶、5×10⁶和2×10⁷ cells/kg）组，每组20只；双后肢交替im给药，每周给药1次，共给药6个月（27次）；试验期间进行大体观察、体质量检查和肿瘤触诊，给药结束进行解剖检查、脏器检查和组织病理学检查。结果 对照组死亡2只动物，其中1只动物颈部出现肿块；HDP-MSCs低剂量死亡1只动物，另有1只动物出现弓背；中剂量组1只动物濒死；高剂量动物未见明显异常；低、中、高剂量组触诊未发现肿瘤。小鼠体质量无异常。解剖后对照组和HDP-MSCs低、中剂量个别动物发现有肿块。各剂量组脏器质量及系数无异常、组织病理学检查无药物相关性病变。结论 HDP-MSCs在本试验剂量下连续im给药6个月，致瘤试验结果为阴性。

Objective To evaluate tumorigenicity of human dental pulp mesenchymal stem cells (HDP-MSCs) on NOG mice. Methods NOG mice were divided into four groups (20 mice each group), which included low, medium, high dose (2×10⁶、5×10⁶ and 2×10⁷ cells/kg) groups and one blank control group. The mice were given HDP-MSCs by alternate intramuscular injection in both hind limbs once a week and this operation last for 6 months (27 times in total). Clinical observation, weight examination and tumor palpation on NOG mice were conducted in experimental observation period. Gross anatomy, organs and histopathology on NOG mice were examined at the end of the experiment.Result Two animals of the blank control group died, one of which had a neck mass. One animal died in the low dose group, and another animal observed one symptoms of arched back. One animal in the middle dose group was in a state of near death. The animals in the high dose group were no obvious abnormality. There was no tumor found on tumor palpation in the low, medium and high dose groups. The mice weight was normal. Tumor was found on autopsy in blank control group, low and medium dose group. Viscera weight and coefficient was no abnormality. No drug-related lesion was found in histopathology.Conclusion The result of tumorigenicity test of HDP-MSCs on NOG mice was negative.

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天津市科技计划项目（17ZXXYSY00020）