研究顯示 寨卡病毒或可治療腦癌

The Zika virus can wreak havoc on the brain of a developing fetus, but its destructive power may also be harnessed to fight a stubborn form of adult brain cancer, researchers said.

研究人員近日稱，雖然寨卡病毒會嚴重損害胎兒大腦，但其破壞性也可以被用來治療一種頑固性成人腦癌。

Early studies have shown the mosquito-borne virus can destroy cells responsible for glioblastoma, the most common form of brain cancer.

早期研究發現，這種蚊傳播的病毒可以破壞導致惡性膠質瘤的細胞，惡性膠質瘤是最常見的一種腦癌。

Glioblastoma affects 12,000 people per year in the United States, and was recently diagnosed in Senator John McCain.

美國每年有1.2萬人患上惡性膠質瘤。最近美國參議員約翰-麥凱恩也被診出患有此病。

The standard treatment is chemotherapy and radiation. But most patients die within two years.

惡性膠質瘤的標準治療方法是化療和放療，但大多數病人生存期不足兩年。

"It is so frustrating to treat a patient as aggressively as we know how, only to see his or her tumor recur a few months later," said Milan Chheda from Washington University School of Medicine.

華盛頓大學醫學院的米蘭·切赫達說：“我們想盡一切辦法治療病人，最後卻發現病人的腫瘤幾個月後就復發了，這真令人沮喪。”

"We wondered whether nature could provide a weapon to target the cells most likely responsible for this return."

“我們想知道大自然能否給我們一種武器，來對付最可能導致這種復發的細胞。”

The secret to Zika's apparent success, the latest experiments show, is that the virus specifically takes aim at brain cancer stem cells, the kind that tend to survive chemotherapy and spread.

最新研究表明，寨卡病毒實驗取得明顯成功的祕密在於，這種病毒會專門攻擊腦癌幹細胞。這種細胞往往能夠在化療中生存下來並繼續擴散。

When a pregnant woman is infected with Zika, she faces a higher risk of bearing an infant with an unusually small head because Zika destroys these cells, leading to the irreversible condition known as microcephaly.

如果孕婦感染寨卡病毒，嬰兒患小頭症的風險會更高，因爲寨卡病毒會破壞這些細胞，造成被稱爲小頭畸形的不可逆損害。

Zika tends to attack neuroprogenitor cells, which are common in fetuses but rare in adults.

寨卡病毒傾向於攻擊神經前體細胞，這種細胞在胎兒體內很常見，但在成人體內數量很少。

"We showed that Zika virus can kill the kind of glioblastoma cells that tend to be resistant to current treatments and lead to death," said study co-author Michael Diamond, a professor of medicine.

醫學教授、研究論文共同作者邁克爾·戴蒙德說：“我們證實，寨卡病毒能夠殺死可抵禦現有治療手段並導致患者死亡的膠質母細胞瘤細胞。”

Researchers injected either Zika virus or a saltwater placebo directly into the brain tumors of 33 mice, said the report in The Journal of Experimental Medicine.

發表在美國《實驗醫學雜誌》期刊上的研究報告稱，研究人員將寨卡病毒或鹽水安慰劑直接注入33只小鼠的腦腫瘤中。

Two weeks later, "tumors were significantly smaller in the Zika-treated mice", the report said. These mice also survived "significantly longer than the ones given saltwater".

報告稱，兩週後，“注射寨卡病毒的小鼠的腦腫瘤小了很多”，其存活時間也比“注射鹽水的小鼠長得多”。

More work is needed before the treatment can be safely attempted in humans.

報道稱，還需要開展更多工作才能在人類患者身上安全地嘗試這種療法。

The virus would likely be injected directly into the brain during surgery to remove the primary tumor.

報道稱，治療時可能會在原發性腫瘤移除手術期間直接將寨卡病毒注入大腦。

Extra studies on Zika's effects on the brain tissue of epilepsy patients showed the virus did not infect noncancerous brain cells.

此外，分析寨卡病毒對癲癇患者腦組織影響的研究表明，這種病毒不會感染沒有癌變的腦細胞。

"We see Zika one day being used in combination with current therapies to eradicate the whole tumor," Chheda said.

切赫達說：“我們認爲，有朝一日會將寨卡病毒和現有療法配合使用，從而根除惡性膠質瘤。”