During World War I, one of the horrors of trench warfare was a poisonous yellow cloud called mustard gas. For those unlucky enough to be exposed, it made the air impossible to breathe, burned their eyes, and caused huge blisters on exposed skin.
一战时期,有一种 黄色的有毒气体, 堪称堑壕战里,最恐怖的梦魇, 它就是“芥子毒气”。 一旦不幸中招, 你将会无法呼吸, 双眼灼伤, 暴露的皮肤上长出巨大的水泡。
Scientists tried desperately to develop an antidote to this vicious weapon of war. In the process they discovered the gas was irrevocably damaging the bone marrow of affected soldiers— halting its ability to make blood cells. Despite these awful effects, it gave scientists an idea. Cancer cells share a characteristic with bone marrow: both replicate rapidly. So could one of the atrocities of war become a champion in the fight against cancer? Researchers in the 1930s investigated this idea by injecting compounds derived from mustard gas into the veins of cancer patients. It took time and trial and error to find treatments that did more good than harm, but by the end of World War II, they discovered what became known as the first chemotherapy drugs.
科学家们穷尽精力,想要研制出 能对抗这残暴武器的解毒剂。 在这个过程中,他们发现气体 对伤员的骨髓造成了永久性损伤, 使它无法继续产生血细胞。 这一糟糕的结果反而 赋予了科学家们灵感。 癌细胞和骨髓细胞有一个共同点: 它们都能快速自我复制 那么,我们能否将战争的暴行 变为对抗癌症的武器呢? 1930 年代的研究学者 对这个想法进行了验证。 他们从芥子气中提取出复合物, 再注入癌症病人的静脉里。 通过长时间反复的试验,他们发现 这种方法利大于弊。 而在第二次世界大战末期, 人们终于发现了 世界上第一种化疗药物。
Today, there are more than 100. Chemotherapy drugs are delivered through pills and injections and use "cytotoxic agents," which means compounds that are toxic to living cells. Essentially, these medicines cause some level of harm to all cells in the body— even healthy ones. But they reserve their most powerful effects for rapidly-dividing cells, which is precisely the hallmark of cancer.
如今,市面上的化疗药物 高达上百种。 患者可以选择口服或者注射, 这是一种“细胞毒剂”, 即对活细胞有毒的化合物。 虽然,这些药物在一定程度上 会损伤身体里的所有细胞, 包括健康的。 但当面对快速分裂的细胞时, 打击效果最佳, 而那正好是癌细胞的标志。
Take, for example, those first chemotherapy drugs, which are still used today and are called alkylating agents. They’re injected into the bloodstream, which delivers them to cells all over the body. Once inside, when the cell exposes its DNA in order to copy it, they damage the building blocks of DNA’s double helix structure, which can lead to cell death unless the damage is repaired. Because cancer cells multiply rapidly, they take in a high concentration of alkylating agents, and their DNA is frequently exposed and rarely repaired. So they die off more often than most other cells, which have time to fix damaged DNA and don’t accumulate the same concentrations of alkylating agents.
举个例子,烷化剂是 我们发现的第一种 并且至今仍在使用的 化疗药物。 这是一种注射型药物, 被输送到所有细胞内。 当 DNA 进行自我复制时 它将破坏 DNA 的双螺旋结构, 从而杀死细胞, 除非损伤被修复。 而正因为癌细胞的繁殖速度快, 吸引烷化剂大量涌入, DNA 在暴露过程中被迅速破坏, 很难自我修复。 所以癌细胞的死亡速度 远远高于其他细胞, 后者有足够时间 自我修复受损的 DNA, 而不会累积过量的烷化剂。
Another form of chemotherapy involves compounds called microtubule stabilizers. Cells have small tubes that assemble to help with cell division and DNA replication, then break back down. When microtubule stabilizers get inside a cell, they keep those tiny tubes from disassembling. That prevents the cell from completing its replication, leading to its death.
第二种化疗药物 含有一种“微管稳定剂”。 细胞内的微管聚集后能 协助细胞分裂、 DNA 复制,然后微管散开, 完成细胞复制。 微管稳定剂进入细胞后, 它们能阻止已经 聚集的微管散开, 从而截断细胞的复制过程, 导致细胞死亡。
These are just two examples of the six classes of chemotherapy drugs we use to treat cancer today. But despite its huge benefits, chemotherapy has one big disadvantage: it affects other healthy cells in the body that naturally have to renew rapidly. Hair follicles, the cells of the mouth, the gastrointestinal lining, the reproductive system, and bone marrow are hit nearly as hard as cancer.
除了上述两种, 还有另外四种化疗药物 被用于现代癌症临床治疗。 尽管化疗有着巨大的好处, 但它有一个明显的缺点: 正常情况下迅速代谢的细胞 也面临着化疗的巨大杀伤力。 毛囊、口腔细胞、 胃肠黏膜、 生殖系统、甚至骨髓, 统统都遭受了无差别攻击。
Similar to cancer cells, the rapid production of these normal cells means that they’re reaching for resources more frequently— and are therefore more exposed to the effects of chemo drugs. That leads to several common side effects of chemotherapy, including hair loss, fatigue, infertility, nausea, and vomiting. Doctors commonly prescribe options to help manage these side-effects, such as strong anti-nausea medications. For hair loss, devices called cold caps can help lower the temperature around the head and constrict blood vessels, limiting the amount of chemotherapy drugs that reach hair follicles. And once a course of chemo treatment is over, the healthy tissues that’ve been badly affected by the drug will recover and begin to renew as usual.
这些正常细胞 和癌细胞一样繁殖迅速, 也就意味着 它们将消耗更多的营养, 与血管内的化疗药物的 反应也更加频繁。 从而导致化疗的各项副作用, 包括脱发、疲劳、不孕不育、 恶心、呕吐等。 通常,为了缓解不适, 医生会给患者开一些药 比如强效的止吐药。 有一种冷却帽, 专门用于防止脱发。 它能降低头皮温度, 收缩血管, 减少化疗药物与毛囊的接触。 当一个疗程的化疗结束后, 之前受损严重的皮肤组织 将恢复健康, 重新开始正常的新陈代谢。
In 2018 alone, over 17 million people world-wide received a cancer diagnosis. But chemotherapy and other treatments have changed the outlook for so many. Just take the fact that up to 95% of individuals with testicular cancer survive it, thanks to advances in treatment. Even in people with acute myeloid leukemia— an aggressive blood cancer— chemotherapy puts an estimated 60% of patients under 60 into remission following their first phase of treatment.
仅在 2018 年,全世界就有超过 1700 万人被确诊癌症。 幸好,化疗以及其他治疗手段 为我们带来了希望的曙光。 超过 95% 的睾丸癌患者重获健康, 而这多亏了医学的进步。 即使像急性髓系白血病 这种严重的血癌, 在接受第一个阶段的化疗后, 约 60% 六十岁以下的 患者的病情得到了缓解。
Researchers are still developing more precise interventions that only target the intended cancer cells. That’ll help improve survival rates while leaving healthy tissues with reduced harm, making one of the best tools we have in the fight against cancer even better.
学者们还在继续研究更准确的, 只针对癌细胞的干预方式, 以期在提高存活率的同时, 减轻对健康组织的伤害, 以改进我们拥有的 最好的抗癌工具之一。