被灭活的PTEN：乳腺癌发病的遗传学机制

More than 10 years ago, scientists discovered that mutations in a gene called BRCA1 lead to a particularly deadly type of breast cancer. Now an international group of researchers has found at least one reason why. BRCA1 inactivates a tumor suppressor gene known as PTEN.
十年前，科学家发现BRCA1基因的突变能导致恶性程度很高的乳腺癌。现在一个国际性的研究团队发现这是由于BRCA1抑制了PTEN的结果，而PTEN是一个抑癌基因。
Mutations occur spontaneously, but most organisms have mechanisms that can prevent the damage they might cause. PTEN has instructions to produce a protein that stops the uncontrolled cell growth of cancer. BRCA1, the scientists reported online Sunday in Nature Genetics, prevents PTEN from doing its work.
突变是自然发生的，但大多数有机体能够防止突变引起的损害。PTEN能够产生一种阻止肿瘤细胞无序生长的蛋白质。科学家在自然遗传学的周日在线上认为BRCA1阻止了PTEN的这一作用。
The researchers found that inactivating the PTEN gene in mice led to the formation of the malignant tumor associated with BRCA1 mutations. Then they examined PTEN in nonhereditary breast tumors from 297 patients and tumors from 34 women who had inherited the BRCA1 mutation. In most cases, the protein that PTEN produces was undetectable in tumor cells, but clearly present in nearby normal cells.
研究人员发现，灭活小鼠的PTEN基因能诱发与BRCA1突变相关的恶性肿瘤的形成。研究人员检查了297例非遗传性乳腺癌患者肿瘤中PTEN基因，同时也检查了34例具有BRCA1突变的遗传性乳腺癌中的PTEN基因的情况。在大多数的病例的肿瘤细胞中都检测不到PTEN产生的蛋白，但这种蛋白存在于周围的正常组织中。
PTEN might be a target for chemotherapy. “I am cautiously optimistic,” said Dr. Ramon E. Parsons, the lead researcher and a professor of pathology at Columbia, “that within the next five years we’ll be using drugs that are effective on the PTEN pathway.”
PTEN可能是化疗的靶点。对此，研究小组的主持者和哥伦比亚大学病理学教授Dr. Ramon E. Parsons对未来5年内能否使有效作用于PTEN通路的药物得到运用保持谨慎的乐观。
Women with BRCA1 mutations are at very high risk for breast cancer at an early age. Those who know they carry the mutation sometimes choose preventive mastectomies
具有BRCA1突变的妇女较早患乳腺癌的风险非常高。这类人群有时选择了预防性的乳腺切除术。