大阅读1-73篇大阅读-36_W

1、 微信公众号：医学博士英语南京医科大学小白老师大阅读第 36 天小白老师医学考博英语网络课程Grow your enemyThe first doctor I saw told me I had six months to live,” says Antonia Crawford.She was diagnosed with advanced pancreatic cancer in August 2013, at the age of 43.She went on to have the standard treatments but, aware that they might not b

2、ethe most effective against her particular cancer, Crawford also did something quiteextraordinary: she had bits of her tumour implanted into a group of mice. Once thetumours had grown in them, the mice were given a range of different treatments, inan effort to find the drug combination that would wo

3、rk best for her. “As a patient, Ijust didnt have the time, nor could my body have gone through trying all thesedifferent drugs on myself,” Crawford says.Its too early to say whether this particular method improves individualschances of survival. But there is a lot of interest in the idea. Many group

4、s are workingon the somewhat grotesque challenge of growing three-dimensional copies ofpeoples tumours outside the body essentially, cloning cancers. Simply put, the ideais that if you want to know your enemy, you need to grow yourenemy.While cancer cells have long been grown outside the body, it is

5、nt as easy as youmight think. Some, such as the famous HeLa strain of cells long used in research,thrive outside the body, but most cancer cells die if they are stuck in a dish. And evenwhen they do survive, there is a big difference between a bunch of cancer cellsgrowing in some fluid in a dish and

6、 a tumour growing in someones body.Solid tumours are a bit like organs: they have a mix of cell types growing in athreedimensional structure and fed by a dedicated blood supply. “How cells behavein 2D in a plastic tissue culture flask is just not that relevant to what happens in thebody,” says Franc

7、es Balkwill of Barts Cancer Institute in London.Balkwills team and others around the world are trying to grow realistic tumoursoutside the body using tissue engineering, but this approach is still at an early stage.The tried and tested way of growing tumours in 3D is to implant bits in mice with ani

8、mmune system altered so as not to attack human cells. Such xenografts have beenused for drug testing since the 1980s.Now Champions Oncology the company that Crawford turned to is sellingthis service directly to individuals with cancer. “Cancer is a unique disease, and it isvery difficult to work out

9、 why some drugs will work for one patient but wont workfor another; we need a more rational way to figure out what patients should andshouldnt try,” says Ronnie Morris, the companys president.This everyone agrees on. Cancers are already classified into hundreds ofdifferent types depending on which t

10、issue they originate in and what they look likeunder a microscope. But really there are many millions of kinds. Cancers typicallyhave hundreds of mutations, along with even more epigenetic changes. Everytumour is unique and constantly changing and evolving. 微信公众号：医学博士英语南京医科大学小白老师So the more closely

11、treatment can be tailored to a persons particular cancer,the more effective it is likely to be. And personalised treatments are starting tobecome a reality. People whose tumours produce too much of a protein called Her2,for instance, are given specific drugs that work against this form of cancer. Ge

12、netictests are also increasingly used to identify mutations known to affect how cancersbehave. But while the field is advancing extremely rapidly, we are still far from thepoint where we can predict the best possible drug combination from genetic testsalone.Indeed, there are reasons to doubt we ever

13、 will reach this point. The cells testedmight not be representative of the whole tumour, for instance. Whats more, thenon-malignant cells in a tumour can have a big effect on the way it evolves andresponds to treatment.This, Morris says, is where Champions can help. “Building a very close replica of

14、their tumour thats alive and continues to grow in a host environment gives patientsthe ability to simultaneously test four or five drugs or combinations, so that they cansee which is the most effective.”In late 2013, Crawford underwent chemotherapy and radiotherapy that shrankher tumour enough for s

15、urgeons to try and remove it from her pancreas. Her brotherpaid for a piece of the tumour to be cut up and implanted on the backs of severalmice. After the tumours had grown somewhat, they were used to “infect” even moremice. Around five months on, Champions had created a small army of what cancerre

16、searchers call mouse “avatars”. These were given combinations of drugs thatgenetic testing suggested might work to see which, if any, could shrink thetumours.Champions says that the animals suffering is minimal because the tumoursgrow just under the skin and dont invade organs. This was an important

17、consideration for Crawford. “I know that animal testing is a sensitive subject, butwhen you find yourself in a position where youre reliant on it, you realise that itsquite vital,” she says. “The only other option for me was to go through it all myself; Iwould be suffering pain, and my time might ru

18、n out.”The process isnt cheap. Just creating the mouse avatars costs around 1500,and it doesnt always work on the first attempt; the success rate is around 70 percent, Morris says. Then its a further 2500 for each drug tested. Given that mostpatients opt to test four or five drugs, thats 11,500 to 14,000. Is it worth it?Preliminary studies by Champions suggest that the mices response to thecancer drugs does reflect what happens in the patient fairly well. In one study, 65mouse avatars were given