The Anti-Cancer “Smart Bomb”

Chronic Myelogenous Leukemia  (CML), diagnosed in 510 Australians every year, is triggered when two chromosomes swap fragments of genetic information. CML starts with the mistaken swap of genes between two chromosomes. The resulting “Philadephia chromosome” produces the mutant Bcr-Abl protein.  Bcr-Abl protein transfers a phosphate from the chemical messenger ATP to other proteins.

A new drug shows hope of conquering a form of leukemia by targeting the misbehaving cells two summers ago. Douglas Jenson was so wiped out from battling CML that he could do little more than sit by his window; watching the numbers on a thermometer rise and fall with the sun. Today thanks to an experimental drug called ST1571, Jenson 67, is biking in Melbourne and planning a trip to the Caribbean. “I feel wonderful,” he said.

So do his doctors. ST1571, a “smart bomb” drug that targets leukemia cells without harming healthy ones, first made headlines last year when researchers announced that white blood counts had returned to normal in 31 out of 31 patients who had taken the pill. 

Last week scientists were back reporting new data on just over 1000 patients. In one trial, more than 90% of 532 people on the drug saw counts return to normal. And under microscopic examination, 28 percent showed no evidence of cancer left in their bone marrow. The drug even helped, although not as dramatically, some patients in the final “blast” phase of the disease, when survival is measured in months.

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参考答案：

抗癌“智能炸弹”

澳大利亚每年有510人被诊断患有慢性骨髓性白血病(Chronic Myelogenous Leukemia, CML)。该病是在两条染色体交换遗传信息片断时引发的。CML源于两条染色体之间错误的基因交换，由此产生的“费城染色体”(“Philadelphia chromosome”)制造出变异Bcr-Abl蛋白质。Bcr-Abl蛋白质从化学信使三磷酸腺苷（ATP）那里向其它蛋白质传送一种磷酸盐。

    两年前，一种新药通过对付不正常细胞的方法给征服一种类型的白血病带来希望。道格拉斯·詹森(Douglas Jenson)由于与CML抗争，身体被搞垮了。他几乎不能做任何事情，每天只能坐在窗边，望着气温计上显示的气温随着太阳起落而升降。由于有了一种叫做ST1571的实验性药物，现在67岁的詹森可以在墨尔本骑自行车并准备去加勒比海旅游。“我感觉好极了，”詹森说道。

    治疗詹森的医生们也感觉好极了。ST1571是一种攻击白血病细胞而不伤害健康细胞的“智能炸弹”型药物。去年，研究人员们宣布服用ST1571的所有31名患者的白血球计数都恢复到正常后，这一药物第一次上了新闻头条。

上个星期，科学家们又对刚好超过1000名患者的新数据做了报告。在一次实验中，使用该药物的532人中90％以上白血球数值恢复到了正常。通过显微镜检验，28％的人显示在他们的骨髓中没有癌症留存的迹象。虽然效果不如上述病例显著，ST1517甚至可以帮助一些晚期恶化的白血病患者。对于这些患者来说，生命是以月份来计数的。