據(jù)3月27日的《科學》雜志報道說,，研究人員已經(jīng)研發(fā)出了一種創(chuàng)制誘導人類多能干細胞（或稱iPS細胞）的方法，在這些細胞中不含外來且可能有害的DNA,。 這些發(fā)現(xiàn)對在基礎生物學研究中所使用的細胞來說是重要的,，而且也是人們向生產(chǎn)iPS細胞這一目標邁出的關鍵性的一步,。
這些iPS細胞可用于醫(yī)療但卻沒有添加到細胞中用來重新設定細胞程序的那些物質(zhì)所帶來的危險。這些添加的物質(zhì)可能會干擾細胞的正常發(fā)育,。 在研究人員首次對胎兒和成人細胞進行重新編程并使其成為iPS細胞的時候,，他們是用基因工程病毒將數(shù)個關鍵性的基因插入到細胞核內(nèi)，并通過它們來開啟重新編程的過程,。年輕華裔科學家俞君英為此項研究的并列通訊作者,。
俞君英及其同僚現(xiàn)在介紹了另外一種方法。 他們將基因添加到被稱作質(zhì)粒的DNA環(huán)中,，而這些質(zhì)粒通常存在于細胞的染色體之外,。 接著，研究人員用一種叫做核轉(zhuǎn)染的方法將這些質(zhì)粒介入到人包皮細胞中,。 在質(zhì)粒中的基因所表達的蛋白質(zhì)會將細胞重新編程并使其成為iPS細胞,。 這些iPS細胞在接著的幾輪細胞分裂中會開始失去這些質(zhì)粒，這樣研究人員就可以分離出不含質(zhì)粒的細胞,。 在文章中,，作者們提到，其它的研究團隊最近也報告了具有同樣目標的實驗方法,，但是這些作者說,，他們的方法才是目前唯一的顯示能夠產(chǎn)生完全不含載體和轉(zhuǎn)基因序列的人類iPS細胞的方法。（生物谷Bioon.com）
更多閱讀：俞君英簡介
生物谷推薦原始出處：
Science March 26, 2009 DOI: 10.1126/science.1172482
Human Induced Pluripotent Stem Cells Free of Vector and Transgene Sequences
Junying Yu 1*, Kejin Hu 2, Kim Smuga-Otto 1, Shulan Tian 3, Ron Stewart 3, Igor I. Slukvin 4, James A. Thomson 5*
1 Morgridge Institute for Research, Madison, WI 53707–7365, USA.; Genome Center of Wisconsin, Madison, WI 53706–1580, USA.; Wisconsin National Primate Research Center, University of Wisconsin–Madison, Madison, WI 53715–1299, USA.
2 Wisconsin National Primate Research Center, University of Wisconsin–Madison, Madison, WI 53715–1299, USA.
3 Morgridge Institute for Research, Madison, WI 53707–7365, USA.; Genome Center of Wisconsin, Madison, WI 53706–1580, USA.
4 Wisconsin National Primate Research Center, University of Wisconsin–Madison, Madison, WI 53715–1299, USA.; Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, Madison, WI 53706, USA.
5 Morgridge Institute for Research, Madison, WI 53707–7365, USA.; Genome Center of Wisconsin, Madison, WI 53706–1580, USA.; Wisconsin National Primate Research Center, University of Wisconsin–Madison, Madison, WI 53715–1299, USA.; Department of Anatomy, University of Wisconsin–Madison, Madison, WI 53706–1509, USA.
* To whom correspondence should be addressed.
Reprogramming differentiated human cells to induced pluripotent stem (iPS) cells has applications in basic biology, drug development, and transplantation. Human iPS cell derivation previously required vectors that integrate into the genome, which can create mutations and limit the utility of the cells in both research and clinical applications. Here, we describe the derivation of human iPS cells using non-integrating episomal vectors. After removal of the episome, iPS cells completely free of vector and transgene sequences are derived that are similar to human embryonic stem (ES) cells in proliferative and developmental potential. These results demonstrate that reprogramming human somatic cells does not require genomic integration or the continued presence of exogenous reprogramming factors, and removes one obstacle to the clinical application of human iPS cells.
