干细胞是细胞的默认状态吗？

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科技日报（2012.4.12）---尽管有相当的研究，在全世界的范围内，我们仍然不知道是什么决定因素来赋予干细胞主要特征：自我更新和分化和增殖的能力。IRB Barcelona的“果蝇的形态发
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生”实验室的负责人和CSIC 的研究专家Jordi Casanova，在杂志上的科学报告中提出，我们可以从错误的角度去研究。
# i' s7 E2 P9 ^* P- h+ Q, r    Casanova的概念是，干细胞的出现并不是因为这些存在的因素，赋予干细胞能力，而是因为这些因素，抑制细胞信号分化和特殊化。Casanova认为：从某种程度上讲，所有的未分化细胞  l* Q' k; M: J1 a
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都具有干细胞的默认的特性并且有能够消除这些特性的因素存在。$ R) T3 Q3 @: s8 ~- w/ c! Y3 _! c; K1 C
    另一种方式说：干细胞之所以称为干细胞就是因为具有分化的潜能。根据Casanova的概念，用默认的干细胞的观点来考虑，研究的重点不应是一个细胞要成为一个干细胞时需要什么，而
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是它必须避开什么。
; s- O" _8 d6 N" I$ h: H    为了支持他自己的观点，Jordi Casanova从这一新的观点的性质和特点分析，目前已知的干细胞和试验是否普遍适应这个假说。本文作者希望这一新的角度能够引起国际科学界的那些致) t- j% x. F% W5 C$ X9 u

* r5 ^8 _' i9 H& E- C力于干细胞和细胞分化研究人员的关注，以支持或者否决这个假设。
+ J. L: l3 _* C& J# @2 r% k   新的认识在这一领域的产生基于对干细胞的潜在治疗应用的的巨大兴趣。
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附原文：
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Could Stem Cells Be the Cells' Default State?
2 l4 w* i8 q/ x0 j3 NScienceDaily (Apr. 12, 2012) — In spite of considerable research efforts around the world, we still do not know the determining factors that confer stem cells their
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main particular features: capacity to self-renew and to divide and proliferate. The scientist Jordi Casanova, head of the "Morphogenesis in Drosophila" lab at IRB
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, g; |' k, l2 W0 g2 w; O! UBarcelona and CSIC research professor, proposes in an article in the journal Embo Reports that we may be working from the wrong angle.) }: D+ v4 j- u6 f3 Q) A

/ |: r  f' x- d' n; W1 {. b! q; H6 MCasanova's notion is that stem cells emerge not because of the presence of factors that confer capacity to the stem cell but because of factors that repress the
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; E, J4 t4 y# V$ D" u- scellular signals for differentiation and specialization. Casanova believes that somehow all non-differentiated cells intrinsically carry the qualities of the stem cell
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by default and that there are factors at work that remove these capacities.
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! h9 r( I! \) cSaid another way: a stem cell is a stem cell because it has evaded differentiation. According to Casanova, if the idea of "a stem cell by default" is considered,
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research should focus not on what a cell requires to become a stem cell but what it must escape from.8 I" \2 d; w( u0 a
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To support his notion, Jordi Casanova analyzes from this new perspective the properties and characteristics currently known about stem cells and tests whether they 4 R9 d* j, H# C6 u( O+ G

) \( R# S6 ?: @+ ggenerally fit the hypothesis. The author of this article hopes that this new angle stimulates research in the international scientific community working on stem cells ) q; @2 ]6 t# a5 Y% V
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and cell differentiation in order to confirm or reject the hypothesis.7 f  c2 o# b9 C8 H' P
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The generation of new knowledge in this field is of enormous interest given the potential of therapeutic applications based on stem cells.
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