疫苗可以帮助消灭由EBV引起的癌症吗？

10月，英国癌症研究（CRUK）推出了癌症研究英国大挑战赛- 一项1亿英镑的计划，以应对理解和治疗癌症的七个最大挑战.

And in a series of posts over the next two months they will be exploring each ofthe seven Grand Challenge questionsset by a panel of the world’s leading cancer experts, the second of whichis posing the question:can we wipe out cancers caused by the Epstein Barr Virus?

TheEpstein-Barr Virus（EBV）是人类最常见的病毒感染之一 - 每20个成年人中约有19个病毒。就被感染的人数而言，它是世界上最多产的病毒之一。

And in most of us, it appears to cause no harm at all. But there’s a sinister side to the virus too. In some people, it can cause cancer. In fact, EBV was thefirst virus found to cause cancer in humans. We now know that, every year, EBV infections trigger 200,000 new cases of cancer – and more than 140,000 deaths – worldwide.

These are mainly certain forms of lymphoma, as well as cancers that start at the back of the nose and throat (thenasopharynx），以及一些胃癌。

Molecules produced by EBV can send infected cells into overdrive, telling them to keep dividing. But diet, genetics and exposure to other infections also play an important role in cancer developing.

在世界某些地区，这种相对常见的感染的黑暗面比其他地区更具感受。中国和东南亚部分地区的癌症发生率提高，而EBV连接的淋巴瘤的发生率尤其遭受了撒哈拉以南非洲的某些部位。

And while expert teams dotted around the globe have chipped away at the challenge of tackling EBV-linked cancers, some believe the geographical spread of these cancers – hitting mainly the developing world – may have stifled interest in studying them.

现在可以将其设置为更改。

A defined and achievable goal

Professor Sir David Lane – Scientific Director of the Ludwig Institute for Cancer Research, Chief Scientist at Singapore’s Agency for Science, Technology and Research (A*STAR) and one of the members of our Grand Challenge Advisory Panel – believes that understanding the trigger behind these tumors actually gives us a real chance of tackling them.

他解释说：“这项挑战的令人兴奋的事情之一是，它具有非常明确的 - 我认为可以实现的目标。”

“这些癌症有一个已知的原因:病毒。我们have a long and successful history of dealing with viruses – either preventing people being infected using vaccines, or successfully treating infections. “There’s no reason we can’t do the same with EBV.”

Lane sees the attempt to stop people becoming infected in the first place, for example through vaccination, as a key focus for this challenge. “There’s a precedent with the success story of vaccines against the human papillomavirus (HPV), which causesseveral types of cancer, notably cervical cancers,” he says.

HPV vaccinesbegan their development in the early 1990s and were rolled out as part of a national programme to immunise schoolgirls in the UK in 2008. The vaccination programme is predicted to save thousands of lives in the future.

And finding a similar way to prevent EBV infection could stop cancers caused by the virus developing, and save lives. But for Lane, there are potentially even bigger benefits ahead – and it’s not just about vaccines.

“There are definitely some cancers we know are caused by EBV. But science is an ever-moving field, and there may be other cancers linked to the virus we don’t know about yet.”

“One theory is that fighting the infection could exhaust or dampen down our immune response, which might help other types of cancer escape immune destruction,” says Lane.

“The important point is that the solution isn’t necessarily a vaccine. There may be ways of uncloaking the virus to immune cells, helping people get rid of the infection themselves rather than having low level infection for years – sometimes their whole lives.”

‘不是缺乏想法使我们退缩了”

Research into EBV-linked cancers has been ongoing for 50 years. And there are a lot of scientists with in depth knowledge of the virus.

But Lane believes that up until now, it’s lacked the momentum that’s needed to turn research into new ways to tackle the disease.

The Grand Challenge would be a significant boost to the efforts of the vaccine research community

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Professor Alan Rickinson

“We’ve had a patchwork of researchers dotted about the world, but no real large, united front to tackle this head on,” he says. “And this is where the Grand Challenge could really turn the tables.”

One of the scientists leading the charge is Professor Alan Rickinson, a Cancer Research UK-funded world leader in EBV research.

他认为，EBV疫苗并没有尽可能地进展的某些原因是缺乏政治意愿，并且从制药行业获得了有限的支持。

“It’s not been lack of ideas that’s held us back,” he says. “We’ve long had the goal of developing a vaccine to protect people from becoming infected with the virus. And the success of the HPV vaccine is a shining example of what science can achieve.”

But viruses are very different from one another, and the development of the HPV vaccine doesn’t automatically mean it will be simple to make an effective EBV vaccine too.

That’s because EBV is very different from HPV. EBV is a type of virus called a ‘herpesvirus’, and at the moment, there are no protective vaccines against any human herpesviruses. “An EBV jab would be a first,” says Rickinson, “and a very important first!”

“The Grand Challenge would be a significant boost to the efforts of the vaccine research community.”

超越疫苗

But while a vaccine would be a big step forwards, there’s also an urgent need for better treatments for the 200,000 patients diagnosed every year with EBV-linked cancers.

南安普敦大学（University of Southampton）的领先的头和颈外科医生艾玛·金（Emma King）正在进行临床试验测试新方法，以增强对癌症的免疫反应，其中许多是由HPV病毒引起的。

“A huge number of cancer cases worldwide are caused by viruses,” she explains. “And one of the big questions we still need to answer is why some people’s immune systems recognise and get rid of viruses, while other people can’t clear the infection and are at risk of developing cancer.”

它可能涉及将疫苗与阻止隐藏免疫细胞的癌细胞的药物结合。

According to King there are several key factors that might play a role – the virus, other infections the immune system has to cope with, lifestyle factors, and of course our genetics.

她认为，治愈这些癌症将需要进行多管齐下的攻击，并且患者之间可能会有所不同。例如，它可能涉及将疫苗与阻止免疫细胞隐藏的癌细胞或放疗与免疫促进药物相结合的药物。

她说：“每个步骤都是朝着正确的方向迈出的一步。”“但是科学很昂贵，大挑战将通过将来自不同领域的专家聚集在一起，帮助我们互相学习，从而帮助提高进步。”

The patient perspective

– Terry, patient panel member for the Grand Challenge

Research has revealed a lot about EBV – and other viruses linked to cancer – over the past 50 years, but the story is just beginning. The viruses themselves are only part of the picture; our genetics and environment also combine to play a role in cancer developing.

但是，凭借我们拥有的所有知识，可以治愈或预防EBV连接的癌症，似乎可以实现这一目标 - 只需要投资就可以使其成为现实。巨大的挑战可以完全提供这一点。

“The whole idea of a ‘Grand Challenge’ is tremendously exciting,” says Lane. “It’s a different way of doing research. It brings scientists across the world together and approaches these large problems by combining a wide breadth of skills, knowledge and technology.”

And with the potential of saving 140,000 lives a year across the world, it will certainly have a big impact.

If you’re a researcher and want to build a team to take on this challenge,访问CRUK的网站，以了解如何申请.