中文摘要：

目的：探讨DLK1过表达对3T3细胞成瘤性的影响。方法：病毒感染法建立3T3-GFP及3T3-DLK1细胞系,集落形成实验检测DLK1过表达对3T3细胞集落形成能力的影响。将2×10^6 3T3、3T3-GFP和3T3-DLK1细胞分别注入裸鼠肩部皮下,测量所形成肿瘤大小以检测DLK1对成瘤性的影响。结果：DLK1过表达使3T3细胞集落形成能力受到抑制;3T3细胞形成集落数为（87.67±6.51）个/孔,3T3-GFP细胞形成集落数为（83.00±6.08）个/孔,3T3-DLK细胞形成集落数为（24.00±2.65）个/孔;3T3-DLK1细胞在裸鼠体内形成的瘤块显著小于对照组,3T3细胞、3T3-GFP细胞和3T3-DLK细胞在裸鼠体内形成瘤块大小分别为（1 111.0±327.4）mm^3、（705.9±415.3）mm^3和（79.91±19.32）mm^3（P〈0.05）。结论：DLK1过表达抑制3T3细胞在裸鼠体内的成瘤性,DLK1可能作为抑癌基因发挥作用。

英文摘要：

Objective：To investigate the effect of DLK1 overexpression on the oncogenicity of 3T3 cells.Method：3T3-GFP,3T3-DLK1 cell lines were established by virus infection.The effect of DLK1 overexpression on the colony formation ability of 3T3 cells was analyzed by clonogenic assays.Nude mice were injected s.c.on the humeral side respectively with 2×106 3T3,3T3-GFP,3T3-DLK1 cells to detect the oncogenicity of DLK1 in vivo.Result：Colony formation ability was inhibited by DLK1 overexpression in 3T3 cells.The colony number was（83.0±6.08）colonies/well for 3T3 cells,（24.00±2.65）colonies/well for 3T3-GFP cells and（87.67±6.51）colonies/well for 3T3-DLK1 cells,respectively.The sizes of tumors formed by 3T3-DLK1 were significantly smaller when compared with those formed by 3T3 or 3T3-GFP（P〈0.05）.The tumor size was（1 111.0± 327.40）mm^3 for 3T3 cells,（705.9± 415.3）mm^3 for 3T3-GFP cells and（79.91± 19.32）mm^3 for 3T3-DLK1 cells,respectively.Conclusion：The overexpression of DLK1 can decrease the oncogenicity of 3T3 cells.DLK1 overexpression may make contribution as an anti-oncogene.