※ 引述《senlin (seize)》之銘言： : ※ [本文轉錄自 Biology 看板] : 作者: senlin (seize) 看板: Biology : 標題: [討論] 從皮膚細胞變成幹細胞 : 時間: Wed Nov 21 07:26:37 2007 : 今天一條很大的新聞 : 日本與美國兩個研究團隊同時在今天發表一項研究成果 : 表示只要在一般人的皮膚細胞中入四個基因後 : 即可將該皮膚細胞轉為幹細胞 Scienec的報導用"retruction" 這個辭來形容 相當的貼切 複製動物的技術體系胞核轉植(SCNT) 也是利用卵母細胞中啟動發育的蛋白來達成reproramming 重新讓轉植細胞核中的基因組回到發育初期的表達狀態 這篇paper的精神就是直接找出那些蛋白(雖然還不完全正確) 然後transgene到皮膚細胞中 讓皮膚細胞的基因組表達狀態重新洗牌 這意味著有可能不需要經過核轉植就可以得到複製性的胚胎幹細胞 美國新保守主義那些人再也無從叫起 胚胎幹細胞研究有可能在明年的美國大選後 獲得空前的大量預算 這仍然有許多的困難 1.皮膚細胞或是其他的體細胞中必然有許多cell specific的蛋白 這些蛋白是否會影響iPS cell的功能或造成與ES cell間的不同?? 2.如何克服老化所產生的基因組損傷 仍是重大的課題 -- 前行之路仍然遙遠 : 不但外觀型態與幹細胞無異 : 此一轉型後的幹細胞也能分化成不同的細胞 : 此項技術將會為幹細胞研究與很多疾病治療的研究帶來重大的突破 : 新聞如下 : http://sciencenow.sciencemag.org/cgi/content/full/2007/1120/1 : Researchers Turn Skin Cells Into Stem Cells : By Gretchen Vogel : ScienceNOW Daily News : 20 November 2007 : Scientists have managed to reprogram human skin cells directly into cells : that look and act like embryonic stem (ES) cells. The technique makes it : possible to generate patient-specific stem cells to study or treat disease : without using embryos or oocytes--and therefore could bypass the ethical : debates that have plagued the field. "This is like an earthquake for both the : science and politics of stem cell research," says Jesse Reynolds, policy : analyst for the Center for Genetics and Society in Oakland, California. : The work builds on a study published last year by Shinya Yamanaka of Kyoto : University in Japan, which showed that mouse tail cells could be transformed : into ES-like cells by inserting four genes (ScienceNOW, 3 July 2006). Those : genes are normally switched off after embryonic cells differentiate into the : various cell types. In June this year, Yamanaka and another group reported : that the cells were truly pluripotent, meaning that they had the potential to : grow into any tissue in the body (ScienceNOW, 6 June). : Now the race to repeat the feat in human cells has ended in a tie: Two groups : report today that they have reprogrammed human skin cells into so-called : induced pluripotent cells (iPCs). In a paper published online in Cell, : Yamanaka and his colleagues show that their mouse technique works with human : cells as well. And in a paper published online in Science, James Thomson of : the University of Wisconsin, Madison, and his colleagues report success in : reprogramming human cells, again by inserting just four genes, two of which : are different from those Yamanaka uses. : In the new work, Yamanaka and his colleagues used a retrovirus to ferry into : adult cells the same four genes they had previously used to reprogram mouse : cells: OCT3/4, SOX2, KLF4, and c-MYC. They reprogrammed cells taken from the : facial skin of a 36-year-old woman and from connective tissue from a : 69-year-old man. Roughly one iPC cell line was produced for every 5000 cells : the researchers treated using the technique, an efficiency that enabled them : to produce several cell lines from each experiment. : Thomson's team started from scratch, identifying its own list of 14 candidate : reprogramming genes. Like Yamanaka's group, the team used a systematic : process of elimination to identify four factors: OCT3 and SOX2, as Yamanaka : used, and two different genes, NANOG and LIN28. The group reprogrammed cells : from fetal skin and from the foreskin of a newborn boy. The researchers were : able to transform about one in 10,000 cells, less than Yamanaka's technique : achieved, Thomson says, but still enough to create several cell lines from a : single experiment. : [下略] -- 如果孔子是那待沽的玉 我便是待斟的酒 用一生的時間 蘊釀自己的濃度 只為等待剎那的傾注 張曉風 釀酒的理由 --

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