奥地利科学家在祖先多细胞动物中发现“原始的”致癌基因

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cyq 发表于 2010-02-22 09:15 | 来源： http://www.lifeomics.com/?p=22002
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8 Q# K1 z& x/ C+ R2 L9 m2 m图片说明：一个祖先多细胞动物干细胞的结构。插图显示了这些细胞中癌基因myc的活性。0 c& X! g2 v( R6 h; A" Z
图片来源：奥地利茵斯布鲁克大学
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' X$ Z1 l0 \7 b8 c# D3 P为了找到癌症发生的起因，奥地利茵斯布鲁克大学（University of Innsbruck）的生物化学和发育生物学家研究了在6亿年前就存在的关键人类癌症基因的功能。他们首次确定了淡水水螅中存在致癌基因myc，结果显示这个致癌基因与在祖先多细胞动物和人类中存在的相同基因具有相同的生物化学功能。科学家将他们的研究结果发表在《美国国家科学院院刊》（PNAS）上。
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/ h  s7 f4 y$ m2 A, Z$ Hmyc基因在生物体的生长发育中起着关键的作用。它能够产生一个起基因调节器的蛋白质，这个蛋白质控制了人类高达15%的基因的表达。这就意味着它能够控制这些基因的激活与失活。myc基因失去控制会导致细胞增殖的失控，最终导致癌症的发生，一个失控的myc基因在30%的人类癌症都出现了。“为了更好地了解由致癌基因导致的失控过程，我们就必须了解myc是调节了哪些基因和哪些是对癌症发生来说是重要的，”奥地利茵斯布鲁克大学生物化学研究所的Klaus Bister表示。由于人类生物体的复杂性，研究人员利用简单的模型系统来进行实验，然后将这个结果应用到人类上。茵斯布鲁克大学科学研究小组的Klaus Bister、Markus Hartl 和 Bert Hobmayer首次确定了淡水水螅中的致癌基因，并发现这种基因具有与人类相同基因一样的功能。1 A0 w: B" i- e+ i5 [! [6 j& Y+ I

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$ _5 i" c' p5 ]3 G干细胞中发现的致癌基因
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& r: u$ F3 L# w4 B. a5 K1 ]" m  V! Z( C两毫米长的水螅是首次发现的6亿年前就存在地球上的多细胞动物之一，在目前仍可以在许多水域中发现。“令人吃惊的是，我们能够在这些简单的生物体中发现致癌基因，”来自动物学研究所的水螅专家Hobmayer表示。“由于这些致癌基因在人类到水螅的进化过程中都保存下来了，我们现在能够对myc基因的生物学和生物化学功能进行详细分析，然后将这些结果应用到人类上，”Klaus Bister补充道。来自茵斯布鲁克大学的研究结果非常有趣，因为他们在水螅的干细胞系统中确定了致癌基因。“我们的实验必将揭开关于干细胞的有趣发现，”Bister教授表示。在淡水水螅中的干细胞强烈地说明了它的再生能力——水螅能够在五天内完全再生，因此，从理论上说它能够无限存在。3 [, i( p! m/ C+ A: c; A# [

- c  ]* B) R. }这个研究获得了奥地利科学基金会（Austrian Science Funds）的赞助。
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! a) ^! v( a- H; i! R原文检索：http://www.sciencedaily.com/releases/2010/02/100211090750.htm6 l% z# Q- K, m/ }0 n. p
Joanne/编译

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& B3 |0 P& J, H9 l2 E4 a'Primitive' Cancer Gene Discovered in Ancestral Metazoan
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ScienceDaily (Feb. 15, 2010) — To find the causes for cancer, biochemists and developmental biologists at the University of Innsbruck, Austria, retraced the function of an important human cancer gene 600 million years back in time. For the first time, they have identified the oncogene myc in a fresh water polyp and they have shown that this oncogene has similar biochemical functions in ancestral metazoan and in humans. The scientists published their findings in PNAS.
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The myc gene plays an important role in the growth of organisms. It produces a protein that acts as a gene regulator, which controls the expression of up to 15 % of all human genes. This means that it controls whether these genes are activated or deactivated. A deregulation of the myc gene leads to uncontrolled cell proliferation and to cancer; a deregulated myc gene occurs in about 30 % of all human cancers. "To get a better understanding of the deregulation process caused by the oncogene, we would have to know which genes are regulated by myc and which of these are important for cancers," says Klaus Bister from the Institute of Biochemistry at the University of Innsbruck. Due to the complexity of the human organism, researchers use simpler model systems for their experiments, whose results may then be translated to humans. The Innsbruck scientific teams of Klaus Bister, Markus Hartl and Bert Hobmayer have, for the first time, identified the oncogene in a fresh water polyp (Hydra) and they have shown that it has very similar functions when compared with humans.. o6 w' W; \8 M1 b$ H0 ?

) k4 c, @9 s8 j+ K" q* jOncogene found in stem cells
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- P) b. q" ?" N, n( aThe two millimeter long Hydra were one of the first metazoans that developed on the earth about 600 million years ago and can still be found in many waters. "It is amazing that we have been able to find this oncogene in such a simple organism," says Hydra expert Hobmayer from the Institute of Zoology. "Because the gene has been conserved in evolution all the way from Hydra to humans, we are now able to analyze biological and biochemical functions of the myc gene in detail and draw conclusions for the human organism," adds Klaus Bister. The findings of the researchers from Innsbruck are particularly interesting because they identified the oncogene in the stem cell system of Hydra. "Our experiments are bound to uncover interesting findings about stem cells," says Prof. Bister. The stem cells in the fresh water polyp strongly indicate its regenerative ability -- the polyp completely regenerates within five days and, thus, it could theoretically age ad infinitum.! d  l  L! |1 @2 W: g& i

5 W; x7 K( I& CThe researchers are supported by the Austrian Science Funds (FWF).9 s2 @0 u3 A) X* H/ w

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