VOA标准英语2012--Researchers Say Malaria Drug Could Also Treat Cancer

Researchers Say Malaria¹ Drug Could Also Treat Cancer

Scientists know that human cancer cells grow by getting energy from adjacent tumors, where cells have begun to self-destruct.

The spread of cancer is accelerated by the death of these cells.

“This process called autophagy, which literally³ means to self-eat, is present in all cells," said Dr. Ravi Amaravadi. "But what we are finding in our research is that cancer cells have a very high level of autophagy even before any treatment, and so they are poised⁴ to take on the damage from existing cancer therapies and simply break down the damaged parts to fuel further growth.”

Dr. Ravi Amaravadi spoke⁵ to us via Skype. He is a cancer specialist at the University of Pennsylvania School of Medicine. His group treated patients by combining conventional cancer medications with the anti-malarial drug, hydroxychloroquine. The compound is known to inhibit⁶ autophagy and researchers hoped it could stop cancer cells from growing.

In clinical trials, scientists found that hydroxychloroquine paired poorly with some cancer drugs. But it worked well with others, such as Temsirolimus, in helping⁷ to halt tumor² growth - a so-called "stable disease" rate - in patients with melanoma, an aggressive skin cancer. 

“And when Temsirolimus [a cancer drug] was tested in melanoma, it had zero percent stable disease rate," said Amaravadi. "And when we combined with hydroxychloroquine malaria drug, the stable disease rate went up to 76 percent so that’s a very big difference.”

Researchers used a high dose of hydroxychloroquine to block autophagy, much higher than what's normally used to treat rheumatoid arthritis⁸ or malaria. The dosage has not yet proved harmful. 

Dr. Davide Ruggero at the University of California, San Francisco, is also studying the growth of cancer cells. He says the results of the research with hydroxychloriquine are promising⁹.

“This is a great discovery because we know that the compounds are not toxic¹⁰ - have already been used," said Ruggero.

But Dr. Amaravadi warns that oncologists should not use the anti-malaria drug outside of clinical settings. He says hydroxychloroquine has severe side effects when combined with some cancer drugs. So the knowledge of which compounds work well together is critical. 

1 malaria   

n.疟疾

参考例句：

• He had frequent attacks of malaria.他常患疟疾。
• Malaria is a kind of serious malady.疟疾是一种严重的疾病。

2 tumor   

n.（肿）瘤，肿块(英)tumour

参考例句：

• 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。

3 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。

4 poised   

a.摆好姿势不动的

参考例句：

• The hawk poised in mid-air ready to swoop. 老鹰在半空中盘旋，准备俯冲。
• Tina was tense, her hand poised over the telephone. 蒂娜心情紧张，手悬在电话机上。

5 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

6 inhibit   

vt.阻止，妨碍，抑制

参考例句：

• Don't let ego and greed inhibit clear thinking and hard work.不要让自我和贪婪妨碍清晰的思维和刻苦的工作。
• They passed a law to inhibit people from parking in the street.他们通过一项法令以阻止人们在街上停车。

7 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

8 arthritis   

n.关节炎

参考例句：

• Rheumatoid arthritis has also been linked with the virus.风湿性关节炎也与这种病毒有关。
• He spent three months in the hospital with acute rheumatic arthritis.他患急性风湿性关节炎，在医院住了三个月。

9 promising   

adj.有希望的，有前途的

参考例句：

• The results of the experiments are very promising.实验的结果充满了希望。
• We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。

10 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。