英国纽卡斯尔大学：紫外光被用来摧毁肿瘤
Newcastle University: Cancer breakthrough as ultraviolet light is used to destroy tumours
在英国科学家取得突破性进展后，紫外光可以用来摧毁肿瘤。
他们开发出了光激活的“灵丹妙药”，通过让外科医生更有效地瞄准肿瘤，给数百万癌症患者带来希望。
这些特殊的分子被注射到血液中，然后通过在身体需要它们的部位照射紫外线来“开启”。
这意味着药物可以针对肿瘤，而不是像癌症药物一样被浪费在全身——冒着损害健康器官的风险。
因为这些特殊的分子只有在光照下才能发挥作用，所以医生可以使用紫外线来确保只有植入肿瘤附近的药物才会被激活。
纽卡斯尔大学的科学家们希望这种方法可以使现有的药物如赫赛汀（Herceotin)更加有效。
首席研究员科林·赛尔夫教授昨晚说:“我认为这种发展就像特效药。”
这项新技术可以用于接近皮肤的肿瘤，如乳腺癌，以及任何可以通过光线探头接触到的癌症。
这些包括消化系统，如胃癌和肠癌，以及泌尿生殖系统，如卵巢癌。
这种疗法使用了一种被称为抗体(antibody)的化学物质，这种化学物质被认为具有巨大的抗癌治疗潜力。但是让他们瞄准身体的特定部位是很困难的。
去年，六名志愿者在伦敦诺斯维克公园医院(Northwick Park Hospital)严重患病，因为他们测试的抗体影响了他们的全身，导致他们的免疫系统超负荷运转。
为了克服这个问题，纽卡斯尔大学的研究小组在一种有机油中隐藏抗体，直到在紫外线的照射下才被激活。
通过用探针照射肿瘤，体内合适位置的抗体就能被激活。身体其他部位的任何抗体都将处于休眠状态，这意味着副作用可以最小化。
激活的抗体然后引起血液中的免疫细胞T细胞攻击癌症。
Self教授说:“这可能意味着一个来接受膀胱癌治疗的病人会注射隐形抗体。
她会在候诊室里坐上一个小时，然后回来接受光照治疗。
“只需几分钟针对肿瘤区域的光疗法就会激活T细胞，使她体内的免疫细胞攻击肿瘤。”
这项研究的详细内容发表在《化学化学》(ChemMedChem)杂志网络版上的两篇论文中。
到目前为止，这项技术只在动物身上进行了试验，但在人类身上的临床试验最早可能在明年开始。
然而，至少要经过10年的严格测试，光线才能用于在医院杀死肿瘤。
英国癌症研究中心的高级科学信息官约瑟芬·奎利多说:“开发一种可以攻击癌细胞但却不会伤害健康组织的治疗方法是癌症研究的圣杯。
“尽管这种新方法还处于非常早期的阶段，但仍有潜力。我们正饶有兴趣地等待进一步研究的结果。”
Cancer breakthrough as ultraviolet light is used to destroy tumours
By DANIEL MARTIN
Last updated at 22:00 29 October 2007
Beams of ultraviolet light could be used to destroy tumours following a breakthrough by British scientists.
They have developed light-activated "magic bullets" which could give hope to millions of cancer victims by allowing surgeons to target tumours much more effectively.
The special molecules are injected into the bloodstream and then "switched on" by shining ultraviolet light on the part of the body where they are needed.
It means drugs can be targeted on tumours rather than being wasted throughout the body as is usual with cancer drugs - running the risk of damaging healthy organs.
Because these special molecules only work when bathed in light, doctors would be able to use ultraviolet rays to ensure that only the drugs embedded near the tumour are switched on.
Scientists from Newcastle University hope the procedure could be used to make existing drugs such as Herceptin much more effective.
Lead researcher Professor Colin Self said last night: "I would describe this development as the equivalent of ultra-specific magic bullets."
The new technique could be used for tumours close to the skin, such as breast cancer, and for any cancers accessible by a light probe.
These include those of the digestive system, such as stomach and bowel cancer, and those of the genito-urinary system, such as ovarian cancer.
The treatment makes use of chemicals called antibodies, which are known to have great potential as anti-cancer treatments. But getting them to target specific parts of the body is difficult.
Six volunteers fell gravely ill at London's Northwick Park Hospital last year because the antibodies they were testing affected their entire body, driving their immune systems into overload.
To get over this problem, the Newcastle team cloaked antibodies in an organic oil which renders them inactive until illuminated by ultra-violet rays.
By using a probe to shine a light on the tumour, the antibodies at the right place in the body can be brought to life. Any antibodies in the rest of the body will remain dormant, meaning side effects can be minimised.
The activated antibodies then cause immune cells in the blood called T-cells to attack the cancer.
Professor Self said: "This could mean that a patient coming in for treatment of bladder cancer would receive an injection of the cloaked antibodies.
She would sit in the waiting room for an hour and then come come back in for treatment by light.
"Just a few minutes of the light therapy directed at the region of the tumour would activate the T-cells causing her body's own immune cells to attack the tumour."
Details of the work are contained in two papers published online in the journal ChemMedChem.
So far the technique has only been tested on animals, but clinical trials on humans could begin as early as next year.
However, it would take at least a decade of rigorous testing before light can be used to kill tumours in hospital.
Josephine Querido, Cancer Research UK's senior science information officer, said: "Developing treatments that attack cancer cells but leave healthy tissue unharmed is the holy grail of cancer research.
"Although at a very early stage, this new approach has potential, and we await the outcome of further research with interest."
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