Scientists Stop Genes that Help Breast Cancer to Spread

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Scientists Stop Genes that Help Breast Cancer to Spread
科学家发现阻断乳腺癌转移的靶基因
US scientists have demonstrated a way to stop breast cancer spreading to other parts of the body by either switching off the genes involved or blocking them with drugs.
美国科学家已经证明了一条阻止乳腺癌全身转移的途径，它通过阻断相关基因或者通过药物阻断它们。
The study is published in the journal Nature.
这项研究结果发表在《Nature》杂志上。
Tumours formed from cancer that has spread or metastased from the primary site to other parts of the body cause 90 per cent of cancer deaths.
90%的癌症死亡是由于肿瘤从基本位点扩散或转移到身体的其他部位。
The process of metastasis or cancer spread is still much of a mystery to scientists. They can't tell the difference between a tumour that won't spread and one that will. And why, when hundreds of tumour cells get into the bloodstream every day, do only a small number of them take up residence in a new site and start multiplying?
对科学家来说，癌症的转移过程至今仍是一个谜。他们并不能说出肿瘤是否会扩散之间的区别。以及为什么，什么时候成百上千的肿瘤细胞进入血液，或者是只有很小数量的肿瘤细胞在一个新的部位定居并开始增殖。
Dr Joan Massagué from the Memorial Sloan-Kettering Cancer Center in New York, US, has been working in this field for some time. He and his team have been looking at cell regulation and how it helps cancer cells to spread to specific tissues.
纽约史隆凯特琳癌症中心的Joan Massagué博士在这个领域研究了一段时间。他和他的团队一直在观察细胞调控及他们如何使肿瘤细胞扩散到特殊组织。
In 2005, they found a number of genes that help breast cancer to metastase to the lungs. In this new study, they have identified four genes in particular that work together to help cells from the primary site to settle at a new site and grow.
2005年，他们发现了许多有助于乳腺癌转移到肺的基因。在这项新的研究中，他们已经鉴定出四个特殊的基因，它们协同作用使肿瘤细胞由原位转移定居在新的位点并生长。
The four genes are: EREG, MMP1, MMP2 and COX2.
这四个基因分别是：EREG，间质金属蛋白酶-1（MMP1），间质金属蛋白酶-2（MMP2）和环氧化酶2（COX2）
Dr Massagué and his team performed two types of experiment. In one they switched off the genes, and in another they targeted them with drugs.
Massagué博士和他的团队完成了两项实验。其一他们切断基因，另一项他们用药物阻断它们。
In the first experiment they took human breast cancer cells and switched off all four genes before inserting them into mice. The tumours did not grow, and metastasis to the lungs was greatly reduced.
在第一项研究中，他们取人乳腺癌细胞，切断所有的四个基因后注入小白鼠体内。发现肿瘤并没有生长，肺转移的几率也大大降低。
However, when they only silenced the genes individually, the effect was nowhere near as dramatic.
然而，当他们只是个别的阻断这些基因，结果与预期相差甚远。
In the second experiment they used a combination of three drugs to inhibit the action of the genes. Two of the drugs have already been approved for clinical use: cetuximab and celecoxib, while the third, GM6001, is still experimental.
第二项实验他们联合用三种药物抑制基因的作用。其中两种药物已经批准应用于临床：西妥昔单抗和塞来考昔，另一种加贝酯则仍在实验中。
The drugs had a similar effect to switching the genes off. And the two approved drugs without the experimental one also stopped the cancer from spreading.
这些药物有相同的阻断基因的作用。除外加贝酯单纯用两种被批准的药物同样可以阻断癌症的扩散。
In speculating on the results, the team suggested the four genes have to work together to help both tumour growth and spread.
根据结果，他们预测这四个基因必须共同作用才能使肿瘤生长并扩散。
They said the genes probably hijack blood vessels and make them feed the tumour instead of healthy cells. Then they help tumour cells get into the bloodstream, penetrate capillary walls in the lungs, become established, and start multiplying.
他们说这些基因可能会劫持血管使它们取代健康细胞而为肿瘤细胞提供营养。接着，它们帮助肿瘤细胞进入血液，穿透肺内的血管壁，使之定居并开始增殖。
So far Dr Massagué and his team have been working with mice; they hope to set up trials with humans very soon. Since two of the drugs are already approved for clinical use, this should speed things up.
到目前为止，Massagué博士和他的团队以小鼠对对象展开研究，他们希望尽快开展人体实验。自从这两种药物被批准用于临床，应该会加快人体实验的进程。
\"You couldn't have it better,\" said Dr Massagué. However, other scientists would prefer to wait for the results of human trials before getting too excited.你们最好不要对此期望过早Massagué博士说。然而，其他科学家更加希望在他们变得兴奋之前知道人体实验的结果。The next stage, said Dr Massagué, is to find women whose breast cancer relies on these four genes. Then they can test whether the drugs they used with the mice will stop the metastasis to the lungs in humans.
下一阶段，目标是找出依赖于这四个基因的乳腺癌患者。然后他们可以测试在实验小鼠身上用的药是否能同样阻止人体的肺转移。
This study makes a significant contribution to the theory of cancer metastasis. Many scientists believe that cancer spread starts after the primary tumour has reached maturity. But this research challenges that and suggests that cancer cells start migrating to other sites from the start. And the same genes that drive the growth of the primary tumour also help the cells to move and settle somewhere else.
这项研究对肿瘤转移理论有重要贡献。许多科学家相信肿瘤在达到成熟期时才开始扩散。但这项研究对这个理论提出挑战，并指出肿瘤细胞从一开始就会发生迁移。驱动原发肿瘤生长的相同的基因同样有助于肿瘤细胞移动并在任何地方定居。
Another potential contribution this study makes is the possibility that these same genes are involved in fuelling metastasis of other cancers, or at least that similar rules are involved. That is the hope expressed by Christoph Klein, who studies metastasis at the University of Regensburg in Germany.
这项研究另一个潜在贡献是证明这些相同的基因与其他癌症的转移相关，至少有相似规律可循的可能性。这个是由德国雷根斯堡大学研究肿瘤转移的Christoph Klein提出的。
While this study sheds valuable light on the mystery of metastasis, there are still areas that puzzle experts. For instance, some patients are diagnosed with metastased tumours without the primary tumour every being found. And nobody knows why different cancers spread to particular tissues, such as why breast cancer travels to lung and bone in particular.
当这项研究对揭开肿瘤转移之谜露出一线光明时，仍有一些领域困惑着专家们。比如说，一些患者在没有找到原发肿瘤就被诊断为转移癌。没有人知道为什么不同的肿瘤扩散到不同的特定组织，就像为什么乳腺癌尤以肺和骨转移。