砒霜可使干细胞致癌（附原文）

yangwy028

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4 l# T& D* I/ u 科学日报（2012.4.4）--在美国国家健康相关机构的研究者们发现砒霜能够使正常的干细胞向癌干细胞转变并刺激肿瘤生长的作用是如此明显。可以影响世界范围内的数百万人的喝水问题的无机砒霜，先前已经被证明是人类的致癌物质。大量的证据表明，癌症是一种干细胞相关的疾病。正常的干细胞对正常组织的再生而言是必需的，对生物过程的稳定性也是必需的。但是癌干细胞则被认为是肿瘤形成、生长和扩散的动力。6 F; V% ~6 v/ i0 H9 h
  Michael Waalkes, Ph.D.和他的团队在国家毒理项目实验室，也就是国家环境卫生科学研究所，属于美国国家卫生研究院的一部分，已经预前证明当正常细胞被无机砒霜处理后会变成癌。这项新的研究表明当这些无机砒霜在附近而不是和正常干细胞直接接触时，正常细胞就能够非常快速的获得癌干细胞的特征。表明恶性肿瘤细胞能够通过细胞通常不能够通过的半透膜释放分子信号，并使正常的干细胞转变成癌干细胞。
  N) t# v( m) R- [* u' M  “这篇论文显示一个不同的独特的方法  癌症能够通过感染附近的正常的干细胞而扩增，并产生非常大量的的癌干细胞。”Waalkes说“补充进去的正常干细胞会变成癌干细胞并被卷入通常的致癌过程包括肿瘤的生长和转移。”
7 B4 t2 a8 H) I' N  ^( q9 v  这个结论显示了砒霜的致癌作用的一个潜在的重要方面，能够帮助解释遵守相关的研究者们认为的砒霜通常可导致多种肿瘤在皮肤或者体内的多种形式转移的惯例。这是一篇环境与健康展望的网上论文。6 I6 @5 Q4 c' _7 Y0 v
   Waalkes的实验室大约是从五年前开始从事干细胞的研究工作的。研究者们当时用的是一个前列腺干细胞系，而不是胚胎干细胞。6 h% J6 C( p* _% K# P- e
  “使用干细胞去解释这些和疾病有关的问题是一个正在发展着的新的重要的研究领域。干细胞能够帮助解释许许多多关于致癌作用，并且它和其他作为慢性疾病的重要影响因素的干细胞极度相像。”Waalkes说道。+ l9 A: v! k# g# H9 {8 ]8 X  K
  干细胞在体内是非常独特的，它们存留很长一段时间并且能够分化和更新它们自己。“大部分的癌症需要30到40年的发展时间。” NIEHS和NTP的主管Linda Birnbaum, Ph.D.说道。“这使: R; l! T- c0 g
得干细胞在成人疾病发展的根据方面可能扮演的一个角色有意义，我们知道有毒物质显露不久就产生和生长，并能够导致生物的后面那一个阶段的疾病。”
2 p6 R' ]7 t) k  下一步，这个实验室团队将展望这项发现是否是砒霜独特的的发现，或者说这项发现对其他的有机和无机的致癌物也是同样适用的。- l/ i- T* l( a

# k% q, ^# B6 L附原文：ScienceDaily (Apr. 4, 2012) — Researchers at the National Institutes of Health have discovered how exposure to arsenic can turn normal stem cells into cancer stem cells and spur tumor growth. Inorganic arsenic, which affects the drinking water of millions of people worldwide, has been previously shown to be a human carcinogen. A growing body of evidence suggests that cancer is a stem-cell based disease. Normal stem cells are essential to normal tissue regeneration, and to the stability of organisms and processes. But cancer stem cells are thought to be the driving force for the formation, growth, and spread of tumors.
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0 H! h- D' \) P* IMichael Waalkes, Ph.D., and his team at the National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, part of NIH, had shown previously that normal cells become cancerous when they are treated with inorganic arsenic. This new study shows that when these cancer cells are placed near, but not in contact with normal stem cells, the normal stem cells very rapidly acquire the characteristics of cancer stem cells. It demonstrates that malignant cells are able to send molecular signals through a semi-permeable membrane, where cells can't normally pass, and turn the normal stem cells into cancer stem cells.
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"This paper shows a different and unique way that cancers can expand by recruiting nearby normal stem cells and creating an overabundance of cancer stem cells," said Waalkes. "The recruitment of normal stem cells into cancer stem cells could have broad implications for the carcinogenic process in general, including tumor growth and metastases."
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, F$ Y' c1 K8 y& p& \2 NThis reveals a potentially important aspect of arsenic carcinogenesis and may help explain observances by researchers working with arsenic that arsenic often causes multiple tumors of many types to form on the skin or inside the body. The paper is online in Environmental Health Perspectives.  e  m( J, M/ `" [

5 W6 s6 C# u  e0 m" q6 qWaalkes' lab started working with stem cells about five years ago. The researchers used a prostate stem cell line, not embryonic stem cells.
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- ]# y+ i5 G, `/ f7 T; w+ h"Using stem cells to answer questions about disease is an important new growing area of research. Stem cells help to explain a lot about carcinogenesis, and it is highly likely that stem cells are contributing factors to other chronic diseases," Waalkes said.
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Stem cells are unique in the body. They stay around for a long time and are capable of dividing and renewing themselves. "Most cancers take 30 or 40 years to develop," said Linda Birnbaum, Ph.D., director of NIEHS and NTP. "It makes sense that stem cells may play a role in the developmental basis of adult disease. We know that exposures to toxicants during development and growth can lead to diseases later in life."* y4 [" c1 L# V, F

" S. ~& X% i1 jNext, the laboratory team will look to see if this finding is unique to arsenic or if it is applicable to other organic and inorganic carcinogens., f6 x5 V# O3 X" J

' D" d* q* u' _, O1 m3楼原文 感谢naturalkillerce 提供

lxm5668

砒霜在中国有申请专利治疗白血病的。4 S9 y0 p+ F, Y
ScienceDaily这则新闻阐述了现象，并没有说明砒霜这种效应的机理。应该再看看他们发的paper.

naturalkillerce

回复 yangwy028 的帖子
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yyshpy

治疗白血病？能使干细胞致癌？

syapxlg

这个研究说明不经转染细胞因子就能使细胞转化，目前的诱导IPS方法大可不必！！！只要环境中提供相应的因子就可以实现的，因此这个研究具有里程碑的意义！！！

syapxlg

本文的标题容易误解，任何一种肿瘤细胞接触其他细胞都可能变化，不只是砷诱导的肿瘤细胞！！

sjmpt

砒霜这种效应的机理是什么？是单纯的砷诱导干细胞的肿瘤方向转化，这可能为我们研究肿瘤发生提供一个思路。“干细胞肿瘤转化”但是具体机制尚需进一步研究！