人類耳聾有望治癒

Scientists have successfully tweaked the DNA of mice with a specific genetic mutation to prevent them from going completely deaf. If the gene-editing technique is proven safe, it could one day be used to treat the same type of hearing loss in people.

科學家已成功調整了攜帶特定基因突變的小鼠的DNA，以預防它們完全失聰。如果能證明基因編輯技術是安全的，那麼有朝一日這一方法或能用於治療人類相同類型的聽力損失。

Researchers injected the gene-editing tool CRISPR-Cas9 inside the ears of live mice with a deafness-causing genetic mutation. The molecular scissors were able to precisely cut the disease-causing copy of the gene without disrupting the healthy copy, according to a study published today in Nature. Even though the researchers think they were able to repair only a small fraction of cells in the ear that prevented treated mice from losing all their hearing.

研究人員將基因編輯工具CRISPR-Cas9注射到活的小鼠的耳內，這些小鼠攜帶耳聾基因突變。《自然》期刊於今日發表的一項研究表明：分子剪刀能夠精確的切割致命基因的拷貝，而且不會破壞健康拷貝。儘管研究人員認爲他們只能修復耳內的一小部分細胞，以防止被治療的小鼠完全失聰。

Gene editing has been making huge strides in the past few years. Just last month, scientists attempted to edit a person's DNA inside his own body for the first time in order to cure a debilitating genetic disorder called Hunter syndrome. The technique described in today's study also attempts to edit DNA inside the body of a living animal - in this case, mice. Though the treatment is still years from coming to a clinic near you, it's an important step in the development of gene therapies, which tinker with genes in order to treat or prevent diseases.

基因編輯在過去幾年裏取得了長足進展。就在上個月，科學家首次嘗試在人體內編輯自己的DNA，以治療一種被稱作亨特氏綜合症的虛弱遺傳疾病。今天研究中描述的這項技術也試圖編輯活體動物體內的DNA--在這種情況下，也就是小鼠。儘管這一治療方法可能還需要好幾年的時間才能應用於臨牀，但這是基因療法發展中的重要一步，這是一種修飾基因以治療或預防疾病的療法。

"We have entered the age where the human genome is a real drug target," says Fyodor Urnov, the associate director at Altius Institute for Biomedical Sciences, who was not involved in the study. The researchers "have provided the first important step and a strong perspective of hope for people who have this mutation."

"我們已經進入了人類基因組真正成爲藥物標靶的時代，"Altius Institute for Biomedical Sciences的副所長費奧多·烏爾諾夫說道，他沒有參與到這項研究。研究人員"爲攜帶這種突變的人提供了重要的第一步、爲他們帶來了強大的希望。"

The gene-editing tool CRISPR-Cas9 is based on a defense mechanism bacteria use to ward off viruses by cutting off bits of their DNA. Scientists have engineered that mechanism to edit pieces of the genetic code, creating unusually muscular beagles, for instance, and mosquitoes that don't transmit malaria. The technique is advancing fast: Last year in China, doctors took immune cells from a patient with lung cancer, edited them, and then injected the cells back into the patient to help defeat the disease.

基因編輯工具CRISPR-Cas9建立在防禦機制細菌的使用基礎之上，通過切斷DNA的位點以抵禦病毒。科學家設計了這種機制來編輯遺傳密碼，例如創造異常的肌肉小獵犬、創造不傳播瘧疾的蚊子。這一技術正在飛速發展：去年在中國，醫生從肺癌患者體內取走了免疫細胞、對這些細胞進行編輯，然後將其重新注回患者體內，以幫助他們戰勝肺癌。