VOA常速英语2008年-Scientists Identify Lung Cancer Genes

By Jessica Berman
Washington
03 April 2008

Three independent teams of researchers have found genes² that may explain why some smokers³ get cancer and others do not, and why some people who never smoke also get the disease. Investigators⁴ say the discoveries could lead to better ways to prevent and treat one of the most lethal⁵ forms of cancer. VOA's Jessica Berman reports.

The teams in the United States, France and Iceland scoured⁶ the DNA⁷ of thousands of white smokers and non-smokers of European descent,with and without lung cancer, looking for genes that have been linked to smoking.

Researchers identified three genetic⁸ variants⁹ that if inherited, increase a person's risk of developing lung cancer from 30 to 80 percent compared to those who do not have the genes.

While cigarette smoking is considered the number one risk factor for lung cancer, only 15 percent of smokers eventually develops the disease, leading doctors to suspect genetics.

Mark Lathrop, co-author of one of the three studies, says it appears many more genes play a role in lung cancer but have yet to be identified. "Undoubtedly¹⁰ with larger studies of the same sort, we'll be able to identify a number of further genetic factors that are involved in the predisposition," he said.

Investigators say that smokers who inherit a full complement¹¹ of the genetic variants have a twenty-three percent increased risk of developing lung cancer.

In all three studies, investigators found a link between smoking and nicotine¹². But only one team of scientists identified a genetic variation that they say causes addiction¹³ to nicotine, including how much a person smokes.

For now, researchers say it's unlikely their work will lead to some kind of a genetics test to determine who is and is not at high risk for lung cancer.

"There's not a public health message here that you know you can find what version of the gene¹ you have and decide whether to keep on smoking or not. Because then also you have to bear in mind that there are so many other diseases that are caused by smoking," said Paul Brennan of the International for Research on Cancer in Lyon, France, who is a senior author of one of the studies.

But investigators say identifying genetic variants in gives scientists targets that can lead to new drugs to treat and possibly prevent lung cancer, a leading cause of cancer death around the world.

Meanwhile, investigators say they are now conducting studies involving Asians and Americans of African descent to try to identify genetic abnormalities that increase the risk of lung cancer in those populations.

Two of the studies on lung cancer were published in the journal Nature and one of the studies in the sister journal, Nature Genetics.

1 gene   

n.遗传因子，基因

参考例句：

• 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   

n.基因( gene的名词复数 )

参考例句：

• 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 smokers   

吸烟者( smoker的名词复数 )

参考例句：

• Many smokers who are chemically addicted to nicotine cannot cut down easily. 许多有尼古丁瘾的抽烟人不容易把烟戒掉。
• Chain smokers don't care about the dangers of smoking. 烟鬼似乎不在乎吸烟带来的种种危害。

4 investigators   

n.调查者，审查者( investigator的名词复数 )

参考例句：

• This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
• The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》

5 lethal   

adj.致死的；毁灭性的

参考例句：

• A hammer can be a lethal weapon.铁锤可以是致命的武器。
• She took a lethal amount of poison and died.她服了致命剂量的毒药死了。

6 scoured   

走遍（某地）搜寻（人或物）( scour的过去式和过去分词 )； （用力）刷； 擦净； 擦亮

参考例句：

• We scoured the area for somewhere to pitch our tent. 我们四处查看，想找一个搭帐篷的地方。
• The torrents scoured out a channel down the hill side. 急流沿着山腰冲刷出一条水沟。

7 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• 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。

8 genetic   

adj.遗传的，遗传学的

参考例句：

• 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。

9 variants   

n.变体( variant的名词复数 )；变种；变型；（词等的）变体

参考例句：

• Those variants will be preserved in the'struggle for existence". 这些变异将在“生存竞争”中被保留下来。 来自辞典例句
• Like organisms, viruses have variants, generally called strains. 与其他生物一样，病毒也有变种，一般称之为株系。 来自辞典例句

10 undoubtedly   

adv.确实地，无疑地

参考例句：

• It is undoubtedly she who has said that.这话明明是她说的。
• He is undoubtedly the pride of China.毫无疑问他是中国的骄傲。

11 complement   

n.补足物，船上的定员；补语；vt.补充，补足

参考例句：

• The two suggestions complement each other.这两条建议相互补充。
• They oppose each other also complement each other.它们相辅相成。

12 nicotine   

n.(化)尼古丁，烟碱

参考例句：

• Many smokers who are chemically addicted to nicotine cannot cut down easily.许多有尼古丁瘾的抽烟人不容易把烟戒掉。
• Many smokers who are chemically addicted to nicotine cannot cut down easily.许多有尼古丁瘾的抽烟人不容易把烟戒掉。

13 addiction   

n.上瘾入迷，嗜好

参考例句：

• He stole money from his parents to feed his addiction.他从父母那儿偷钱以满足自己的嗜好。
• Areas of drug dealing are hellholes of addiction,poverty and murder.贩卖毒品的地区往往是吸毒上瘾、贫困和发生谋杀的地方。