文章来源:未知 文章作者:meng 发布时间:2010-05-03 02:56 字体: [ ]  进入论坛

Researchers from the University of Leeds, UK, the Charité University Medical School and the Max Delbrück Centre for Molecular1 Medicine (MDC) in Berlin, Germany, have discovered a new driving force behind cancer growth. Their studies have identified how 'junk' DNA2 promotes the growth of cancer cells in patients with Hodgkin's lymphoma(淋巴瘤) . Professor Constanze Bonifer (University of Leeds) and Dr Stephan Mathas (Charité, MDC) who co-led the study suspect that these pieces of 'junk' DNA, called 'long terminal repeats', can play a role in other forms of cancer as well. The work is published in Nature Medicine.

The researchers uncovered the process by which this 'junk DNA' is made active, promoting cancer growth.

"We have shown this is the case in Hodgkin's lymphoma, but the exact same mechanism3 could be involved in the development of other forms of blood cancer," said Prof. Bonifer. "This would have implications for diagnosis4, prognosis(预知) , and therapy of these diseases."

'Long terminal repeats' (LTRs) are a form of 'junk DNA' - genetic5 material that has accumulated in the human genome over millions of years. Although LTRs originate from viruses and are potentially harmful, they are usually made inactive when embryos6(胚胎,晶胚) are developing in the womb(子宫) .

If this process of inactivation7 doesn't work, then the LTRs could activate9 cancer genes10, a possibility that was suggested in previous animal studies. This latest research has now demonstrated for the first time that these 'rogue11' active LTRs can drive the growth of cancer in humans.

The work focused on cancerous cells of Hodgkin's lymphoma (the Hodgkin-/Reed Sternberg cells) that originate from white blood cells (antibody-producing B cells). Unusually, this type of lymphoma cell does not contain a so-called 'growth factor receptor' that normally controls the growth of other B-cells.

They found that the lymphoma cells' growth was dependent on a receptor that normally regulates the growth of other immune cells, but it is not usually found in B-cells. However in this case, the Hodgkin-/Reed Sternberg cells 'hijacked12' this receptor for their own purposes by activating13 some of the 'junk DNA'. In fact the lymphoma cells activated14 hundreds, if not thousands, of LTRs all over the genome, not just one.

Hodgkin-/Reed Sternberg cells may not be the only cells that use this method to subvert15(推翻,颠覆) normal controls of cell growth. The researchers found evidence of the same LTRs activating the same growth receptor in anaplastic(还原成形术的) large cell lymphoma, another blood cancer.

The consequences of such widespread LTR activation8 are currently still unclear, according to the study's authors. Such processes could potentially activate other genes involved in tumour16 development. It could also affect the stability of chromosomes17 of lymphoma cells, a factor that may explain why Hodgkin-/Reed Sternberg cells gain many chromosomal18(染色体的) abnormalities over time and become more and more malignant19(恶性的,有害的) .


1 molecular mE9xh     
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时,分子的碰撞就停止了。
2 DNA 4u3z1l     
(缩)deoxyribonucleic acid 脱氧核糖核酸
  • DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
  • Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。
3 mechanism zCWxr     
  • The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
  • The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。
4 diagnosis GvPxC     
  • His symptoms gave no obvious pointer to a possible diagnosis.他的症状无法作出明确的诊断。
  • The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做一次彻底的调查分析。
5 genetic PgIxp     
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
6 embryos 0e62a67414ef42288b74539e591aa30a     
n.晶胚;胚,胚胎( embryo的名词复数 )
  • Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段,而且其行为象胚。 来自辞典例句
  • Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句
7 inactivation 18ae5d115854e3d37d23b02949a1e431     
  • This inactivation may be accomplished in a variety of ways. 这种失去活性作用能以多种方式来实现。 来自辞典例句
  • Long sonication periods can lead to some inactivation. 长时间的声波作用可导致某种程度的失活。 来自辞典例句
8 activation 24eed33ee38027d124839f0fcdf6adcb     
n. 激活,催化作用
  • A computer controls the activation of an air bag.电脑控制着气囊的启动。
9 activate UJ2y0     
  • We must activate the youth to study.我们要激励青年去学习。
  • These push buttons can activate the elevator.这些按钮能启动电梯。
10 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
11 rogue qCfzo     
  • The little rogue had his grandpa's glasses on.这淘气鬼带上了他祖父的眼镜。
  • They defined him as a rogue.他们确定他为骗子。
12 hijacked 54f3e68c506e45e75f9a155a27738c2f     
劫持( hijack的过去式和过去分词 ); 绑架; 拦路抢劫; 操纵(会议等,以推销自己的意图)
  • The plane was hijacked by two armed men on a flight from London to Rome. 飞机在从伦敦飞往罗马途中遭到两名持械男子劫持。
  • The plane was hijacked soon after it took off. 那架飞机起飞后不久被劫持了。
13 activating 948eea612456562bf255d3a9c59c40a3     
  • "I didn't say we'd got to stop activating the masses! “我并没说就此不发动! 来自子夜部分
  • Presumably both the very small size and activating influence of fluorine atoms contribute to this exception. 这大概是由于氟原子半径小和活性高这两个原因的影响,氟原子对这种例外做出了贡献。
14 activated c3905c37f4127686d512a7665206852e     
adj. 激活的 动词activate的过去式和过去分词
  • The canister is filled with activated charcoal.蒸气回收罐中充满了活性炭。
15 subvert dHYzq     
  • The rebel army is attempting to subvert the government.反叛军队企图颠覆政府统治。
  • They tried to subvert our state and our Party. This is the crux of the matter.他们是要颠覆我们的国家,颠覆我们的党,这是问题的实质。
16 tumour tumour     
  • The surgeons operated on her for a tumour.外科医生为她施行了肿瘤切除手术。
  • The tumour constricts the nerves.肿瘤压迫神经。
17 chromosomes 11783d79c0016b60332bbf1856b3f77d     
n.染色体( chromosome的名词复数 )
  • Chromosomes also determine the sex of animals. 染色体也决定动物的性别。 来自《简明英汉词典》
  • Each of four chromosomes divide longitudinally. 四种染色体的每一种都沿着纵向分裂。 来自《现代汉英综合大词典》
18 chromosomal 13a3145acf874e52d34a5554025f79c6     
  • Like mRNA, both tRNA and rRNA are transcripts of chromosomal DNA. tRNA及rRNA同mRNA一样,都是染色体DNA的转录产物。 来自辞典例句
  • In mammalian species, a variety of chromosomal rearrangements are known to exist. 在哺乳类的物种中,已知有许多类型的染色体内部重新排列。 来自辞典例句
19 malignant Z89zY     
  • Alexander got a malignant slander.亚历山大受到恶意的诽谤。
  • He started to his feet with a malignant glance at Winston.他爬了起来,不高兴地看了温斯顿一眼。
TAG标签: cells DNA cancer lymphoma