利用ES细胞建立可诱导的白血病模型

胚胎干细胞（embryonic stem cells,ESCs）是从囊胚的内细胞团分离出来的多潜能干细胞,具有多向分化的能力。将外源基因导入ES细胞建立转基因动物,对于研究外源基因的功能和调控具有一定的价值。载有外源性基因的病毒在感染ES细胞后,可通过囊胚注射获得具有胚系遗传的该转基因动物,并且这一外源基因可以稳定遗传和表达。该研究主要是利用携带hPML-RARα基因的慢病毒感染小鼠ES细胞系（R1）,获得携带该基因的ES细胞,感染后的ES细胞核型正常。在此基础上,将感染后的ES细胞经囊胚注射,获得了携带有hPML-RARα基因的3只嵌合小鼠,其中,有1只具有遗传特性。对嵌合体小鼠与C57杂交的后代给予强力霉素（doxycycline）处理,3天以后骨髓细胞hPML-RARα基因开始表达,这证明了在小鼠体内该外源基因表达的可诱导性。以上证实,已经成功利用ES细胞建立了可诱导的白血病转基因小鼠模型。

Establishing A Leukemia-inducible Model with ES Cells

Embryonic stem cells are pluripotent cell lines isolated from the inner cell mass of blastocyst that have the potential for multi-lineage differentiation.Transgenic animals are generated by introducing exogenous gene into ES cells.This approach has been used successfully for the analysis of gene function and regulation.Transfer of ES cells that contain virus-transduced transgene into blastocysts can also generate transgenic animals with germ-line transmission that stably express the transgene in mouse tissues.In this study,we confirmed that lentiviruses containing our construct can efficiently deliver hPML-RARa to murine ES cells with normal karyotypes.The infected ES cells were injected into blastocysts and then transplanted into pseudo-pregnant mice.Three chimeric mice carrying hPML-RARa were obtained with one confirmed as germ-line transmission competent.We then fed mice bearing the transgene with doxycycline in vivo and observed the expression of hPML-RARa in bone marrow cells after 3 days of Dox administration.It showed that the exogenous gene expression could be induced in vivo.Our results demonstrate that we have successfully established a leukemia-inducible transgenic mouse model with ES cells.