文章来源:未知 文章作者:enread 发布时间:2011-07-19 00:57 字体: [ ]  进入论坛

Oncogenes(致癌基因) are generally thought to be genes2 that, when mutated, change healthy cells into cancerous tumor3 cells. Scientists at the Keck School of Medicine of the University of Southern California (USC) have proven that those genes also can change normal cells into stem-like cells, paving the way to a safer and more practical approach to treating diseases like multiple sclerosis(多发性硬化) and cancer with stem cell therapy. "The reality may be more complicated than people think," said Jiang F. Zhong, Ph.D., assistant professor of pathology at the Keck School. "What is a stem cell gene1? What is a cancer gene? It may be the same thing."

Zhong and colleagues at the Children's Hospital of Orange County (CHOC) in California and Good Samaritan Hospital Medical Center in New York successfully converted human skin cells into brain cells by suppressing the expression of p53, a protein encoded by a widely studied oncogene. This suggests that p53 mutation4 helps determine cell fate — good or bad — rather than only the outcome of cancer.

The study is slated5 to appear in the online edition of Proceedings6 of the National Academy of Sciences, a peer-reviewed scientific journal, the week of July 18, 2011.

"When you turn off p53, people think the cell becomes cancerous because we tend to focus on the bad thing," Zhong said. "Actually, the cell becomes more plastic and could do good things, too. Let's say the cell is like a person who loses his job (the restriction7 of p53). He could become a criminal or he could find another job and have a positive effect on society. What pushes him one way or the other, we don't know because the environment is very complicated."

Stem cells can divide and differentiate8 into different types of cells in the body. In humans, embryonic9 stem cells differentiate into three families, or germ layers, of cells. The reasons why and how certain stem cells differentiate into particular layers are not clearly understood. However, from those layers, tissues and organs develop. The endoderm(内胚层) , for example, leads to formation of the stomach, colon10 and lungs, while the mesoderm(中胚层) forms blood, bone and heart tissue. In its study, Zhong's team examined human skin cells, which are related to brain and neural11 cells from the ectoderm(外胚层) .

When p53 was suppressed, the skin cells developed into cells that looked exactly like human embryonic stem cells. But, unlike other man-made stem cells that are "pluripotent" and can become any other cells in the body, these cells differentiated12 only into cells from the same germ layer, ectoderm.

"IPSCs [induced pluripotent stem cells] can turn into anything, so they are hard to control," Zhong said. "Our cells are staying within the ectoderm lineage."

Zhong said he expects that suppressing other oncogenes in other families of cells would have the same effect, which could have critical significance for stem cell therapy. Future research should focus on determining which genes to manipulate, Zhong said.


1 gene WgKxx     
  • A single gene may have many effects.单一基因可能具有很多种效应。
  • The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。
2 genes 01914f8eac35d7e14afa065217edd8c0     
n.基因( gene的名词复数 )
  • You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因,所以能够活得很长。 来自《简明英汉词典》
  • Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
3 tumor fKxzm     
  • He was died of a malignant tumor.他死于恶性肿瘤。
  • The surgeons irradiated the tumor.外科医生用X射线照射那个肿瘤。
4 mutation t1PyM     
  • People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
  • So far the discussion has centered entirely around mutation in the strict sense.到目前为止,严格来讲,讨论完全集中于围绕突变问题上。
5 slated 87d23790934cf766dc7204830faf2859     
用石板瓦盖( slate的过去式和过去分词 )
  • Yuki is working up an in-home phonics program slated for Thursdays, and I'm drilling her on English conversation at dinnertime. Yuki每周四还有一次家庭语音课。我在晚餐时训练她的英语口语。
  • Bromfield was slated to become U.S. Secretary of Agriculture. 布罗姆菲尔德被提名为美国农业部长。
6 proceedings Wk2zvX     
  • He was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
7 restriction jW8x0     
  • The park is open to the public without restriction.这个公园对公众开放,没有任何限制。
  • The 30 mph speed restriction applies in all built-up areas.每小时限速30英里适用于所有建筑物聚集区。
8 differentiate cm3yc     
  • You can differentiate between the houses by the shape of their chimneys.你可以凭借烟囱形状的不同来区分这两幢房子。
  • He never learned to differentiate between good and evil.他从未学会分辨善恶。
9 embryonic 58EyK     
  • It is still in an embryonic stage.它还处于萌芽阶段。
  • The plan,as yet,only exists in embryonic form.这个计划迄今为止还只是在酝酿之中。
10 colon jqfzJ     
  • Here,too,the colon must be followed by a dash.这里也是一样,应当在冒号后加破折号。
  • The colon is the locus of a large concentration of bacteria.结肠是大浓度的细菌所在地。
11 neural DnXzFt     
  • The neural network can preferably solve the non- linear problem.利用神经网络建模可以较好地解决非线性问题。
  • The information transmission in neural system depends on neurotransmitters.信息传递的神经途径有赖于神经递质。
12 differentiated 83b7560ad714d20d3b302f7ddc7af15a     
区分,区别,辨别( differentiate的过去式和过去分词 ); 区别对待; 表明…间的差别,构成…间差别的特征
  • The development of mouse kidney tubules requires two kinds of differentiated cells. 小鼠肾小管的发育需要有两种分化的细胞。
  • In this enlargement, barley, alfalfa, and sugar beets can be differentiated. 在这张放大的照片上,大麦,苜蓿和甜菜都能被区分开。
TAG标签: People cells cancer