三维培养转导Sox2诱导人颊黏膜上皮干细胞为iPSC的研究

项目名称： 三维培养转导Sox2诱导人颊黏膜上皮干细胞为iPSC的研究

项目编号： No.81200796

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 医学二处

项目作者： 乔彬

作者单位： 郑州大学

项目金额： 23万元

中文摘要： 经典"四因子转导法"(Oct4, Sox2, Klf4 和c-Myc) 被证实是最高效获得诱导多能干细胞(iPSC)的方法。课题申请人参与的国家自然科学基金(81072227)通过转染hTERT基因入原代培养的颊黏膜上皮细胞，建立上皮细胞→永生化上皮细胞→干细胞样永生化上皮细胞→癌干细胞四阶段致癌模型，发现上皮-间充质转化、间充质-上皮转化参与了干细胞样永生化上皮细胞的形成。由于间充质-上皮转化被认为是iPSC重编程的起始步骤，已获得的干细胞样永生化上皮细胞(hTERT+-OME)在三维培养下自发高表达"四因子转导法"中的Oct4基因。因此本课题提出在三维条件下采用细胞甩片技术进一步转导Sox2基因入hTERT+-OME上皮细胞球，有望获得诱导多能干细胞。课题不仅为高效获得iPSC提供一条潜在途径，同时提示iPSC与癌干细胞之间的同源关系，即成体干细胞可能是iPSC和癌干细胞的共同起源。

中文关键词： 重编程；Oct4；Sox2；肿瘤发生；

英文摘要： Somatic cells can be reprogrammed into induced pluripotent stem cells (iPSC) by the transcription factors Oct4, Sox2, and Klf4 in combination with c-Myc. However, the mechanism of the reprogramming is unclear. It has been proposed that Oct4 and Sox2 may govern the pluripotency of iPSC while Klf4 and c-Myc could contribute to the cell proliferation via immortalization. In our previous study that was supported by National Natural Science Foundation of China (Grant No. 81072227), we established an immortalized oral mucosal epithelial cell line (hTERT+-OME) by human telomerase reverse transcriptase (hTERT) gene transfection. It was found that epithelial-mesenchymal transition (EMT) spontaneously occurred in hTERT+-OME cells and endowed those cells with stem cell properties. Furthermore, when hTERT+-OME cells were cultured in suspension they could form spheroids. Meantime, hTERT+-OME spheroids regained their epithelial properties via mesenchymal-epithelial transition (MET) and enriched the nuclear expression of Oct4. Due to the fact that MET is recognized as the initial step of reprogramming into iPSC, we proposed in this study that if re-expression of Sox2 in hTERT+-OME spheroids may induce hTERT+-OME cells to enter a state very similar to that of iPSC. Because cell immortalization is recognized as the middle step

英文关键词： reprogramming；oct4；sox2；tumorigenesis；