※ 引述《senlin (seize)》之铭言： : ※ [本文转录自 Biology 看板] : 作者: senlin (seize) 看板: Biology : 标题: [讨论] 从皮肤细胞变成干细胞 : 时间: Wed Nov 21 07:26:37 2007 : 今天一条很大的新闻 : 日本与美国两个研究团队同时在今天发表一项研究成果 : 表示只要在一般人的皮肤细胞中入四个基因後 : 即可将该皮肤细胞转为干细胞 Scienec的报导用"retruction" 这个辞来形容 相当的贴切 复制动物的技术体系胞核转植(SCNT) 也是利用卵母细胞中启动发育的蛋白来达成reproramming 重新让转植细胞核中的基因组回到发育初期的表达状态 这篇paper的精神就是直接找出那些蛋白(虽然还不完全正确) 然後transgene到皮肤细胞中 让皮肤细胞的基因组表达状态重新洗牌 这意味着有可能不需要经过核转植就可以得到复制性的胚胎干细胞 美国新保守主义那些人再也无从叫起 胚胎干细胞研究有可能在明年的美国大选後 获得空前的大量预算 这仍然有许多的困难 1.皮肤细胞或是其他的体细胞中必然有许多cell specific的蛋白 这些蛋白是否会影响iPS cell的功能或造成与ES cell间的不同?? 2.如何克服老化所产生的基因组损伤 仍是重大的课题 -- 前行之路仍然遥远 : 不但外观型态与干细胞无异 : 此一转型後的干细胞也能分化成不同的细胞 : 此项技术将会为干细胞研究与很多疾病治疗的研究带来重大的突破 : 新闻如下 : 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 用一生的时间 蕴酿自己的浓度 只为等待刹那的倾注 张晓风 酿酒的理由 --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 221.169.50.122 Orz sorry ※ 编辑: boyo 来自: 221.169.50.122 (11/21 23:41)