VOA慢速英语2019 医生报告美国首次基因编辑治疗癌症试验（在线收听）

Doctors Report First US Tests of Gene Editing for Cancer

Doctors have reported on the first attempts in the United States to use gene editing to help patients fight cancer.

医生报告了美国利用基因编辑帮助患者对抗癌症的首次尝试。

The doctors say one form of gene editing appeared to be safe when tested in three patients. But it is not yet known what long-term effects the method will have on cancer treatment or patient survival rates.

医生表示，在三名患者身上进行测试后，似乎能证明一种基因编辑是安全的。但目前尚不清楚这种方法会对癌症治疗或患者存活率有何长期影响。

A gene editing tool called CRISPR/Cas9 was used in the tests, which were recently reported in a medical study. The method was discovered in recent years as a way to change the genetic material that make up a person's DNA.

测试中使用了一种名为CRISPR/Cas9的基因编辑技术，一项医学研究最近报告了这种方法。最近几年，这一方法被发现可以用来改变构成人类DNA的遗传物质。

DNA is short for deoxyribonucleic acid. It is the substance that carries genetic information in the cells of living things. The CRISPR tool makes it possible to change DNA to add needed genes or take some away if they lead to problems.

DNA是脱氧核糖核酸的简称。这是一种携带活体细胞遗传信息的物质。CRISPR技术使改变DNA成为可能，改变的目的是增加所需基因或去除某些引发问题的基因。

Cancer researchers from the University of Pennsylvania Health System took immune system cells from the blood of the three patients. They changed the structure of the cells' genes to help them recognize and fight cancer. They were then put back in the patients. The researchers said the editing process was completed with no serious side effects.

美国宾西法尼亚大学医疗体系的癌症研究人员从三名患者的血液中提取了免疫系统细胞。他们改变了这些细胞的基因结构，以帮助识别并对抗癌症。之后，他们将编辑后的细胞放回患者体内。研究人员表示，完成编辑过程没有产生任何副作用。

The treatment removed three genes that might have been restricting the ability of the immune system cells to attack the cancer. A new, fourth gene was added to help the others work effectively.

这种治疗方法移除了三个基因，因为这些基因可能一直在限制免疫系统细胞攻击癌症的能力。之后，将第四个新细胞导入患者体内，以帮助其他细胞有效地工作。

Two of the patients suffer from multiple myeloma, a blood cancer, and the third has sarcoma, cancer that forms in connective or soft tissue. All had failed with repeated traditional cancer treatments.

接受测试的三名患者中，两名患有多发性骨髓瘤，这是一种血癌，另外一名患者患有肉瘤，这是在结缔组织或软组织中形成的癌症。所有患者在接受多种传统癌症疗法后均没有效果。

"It's the most complicated genetic, cellular engineering that's been attempted so far," the study's leader, Edward Stadtmauer, told The Associated Press (AP). "This is proof that we can safely do gene editing of these cells."

这项研究的领导者爱德华·斯塔特马尔对美联社（简称AP）表示：“这是迄今为止我们尝试过的最复杂的遗传和细胞工程。这证明我们能安全地对这些细胞进行基因编辑。”

So far, the cells have survived and have been reproducing as they should be, Stadtmauer said.

斯塔特马尔表示，截至目前，这些细胞已经存活，而且一直在正常繁殖。

After two to three months, one patient's cancer continued to worsen, while the condition of another patient was unchanged. The third patient was treated too recently to effectively measure her progress. The researchers plan to expand the experimental treatment to 15 more patients.

2-3个月后，一名患者的病情继续出现了恶化，另外一名患者的病情则相对稳定。第三名患者接受治疗的时间较短，目前尚无法有效地衡量其病情发展。研究人员计划再对15名患者进行治疗。

Stadtmauer said that since the gene editing treatment is so new, it is not clear how soon major anti-cancer effects will be seen. Patients must be followed further and more tests will be needed, he said.

斯塔特马尔说，由于基因编辑是一种全新的疗法，目前尚不清楚何时能在患者体内观察到重大抗癌效果。他说，必须对患者进行进一步追踪研究，而且需要进行更多测试。

"It's very early, but I'm incredibly encouraged by this," one independent expert, Aaron Gerds, told an AP reporter.

独立专家亚伦·格斯对美联社记者表示：“现在还为时尚早，不过我已经备受鼓舞。”

Gerds is a cancer specialist at the Cleveland Clinic in Cleveland, Ohio. He added that other cell therapies for some blood cancers have worked very well, even "taking diseases that are uncurable and curing them." He said gene editing could provide a way to improve on those treatments.

格斯是俄亥俄州克利夫兰医学中心的癌症专家。他补充说，治疗某些血癌的其他细胞疗法也有非常好的效果，甚至“是接受无法治愈的疾病并治疗它们”。他表示，基因编辑可以提供改善这些治疗的方法。

Chinese scientists are reported to have attempted the CRISPR method on cancer patients. The U.S. study is the first known research to be completed outside China. It took researchers over two years to get approval from the U.S. government to try it.

据报道，中国科学家已经尝试用CRISPR技术来治疗癌症患者。美国的研究是中国以外地区完成的首个已知研究。研究人员花了两年多的时间才得到美国政府的批准，得以进行尝试。

More details about the study are to be provided at the yearly conference of the American Society of Hematology in December.

这项研究的更多详细情况将在12月举行的美国血液学会年会上公布。

Words in This Story

editing – n. the act of reforming or reorganizing

immune – adj. not capable of being affected by a disease; producing antibodies to fight disease

complicated – adj. involving a lot of different parts in a way that can be difficult to understand

encourage – v. attempt to make someone more likely to do something