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【bio-news】研究发现无脂肪小鼠具有抗癌能力
Study: Leaner mice able to fight tumors
By LAURAN NEERGAARD
AP MEDICAL WRITER
WASHINGTON -- Fatty tissue may decrease the body's ability to kill off cancer, says a study that found making mice leaner - through exercise or surgery - seemed to help them fight skin tumors.
Scientists have long known that people who are overweight are at increased risk of certain types of cancer. The question is why, and whether slimming down will lower that risk or do any good after a tumor forms.
Rutgers University scientists took a closer look at that question using mice engineered to get skin cancer, and reported Monday that fat cells may secrete substances that short-circuit one of the body's main anti-tumor defenses.
When cells become genetically damaged - such as the DNA damage caused by the sun's ultraviolet rays - they're supposed to self-destruct. It's a process called apoptosis that helps clear out bad cells before they can grow into tumors.
The Rutgers' team put running wheels in the cages of some laboratory mice. They apparently loved the new toy, logging an estimated 2 to 3 miles a day, estimated professor Allan Conney, director of cancer research in Rutgers' pharmacy school.
After two weeks, the mice hadn't lost weight but had lost a significant amount of fat in favor of muscle when compared to sedentary mice.
[被屏蔽广告]More importantly, the exercising mice experienced higher levels of apoptosis - the self-destruction of bad cells - in both sun-damaged skin and in already-formed skin tumors, Conney found.
The researchers then tried the experiment again, this time surgically removing pads of fat from chubby mice instead of having them exercise. Getting rid of fat stimulated tumor-cell death, they report in the journal Proceedings of the National Academy of Sciences.
That suggests something in fat lowers normal levels of cancer-fighting apoptosis. Now Conney is trying to figure out what.
What happens in mice doesn't always happen in people, cautioned Dr. Len Lichtenfeld, the American Cancer Society's deputy chief medical officer.
"We have a long way to go to prove" if cutting fat really cuts cancer, he said. But, "this particular study certainly provides a biologic rationale or explanation about why weight loss may be helpful."
In people, studies to date are conflicting. There's some evidence that a low-fat diet may reduce the risk of breast cancer returning, for instance, while other studies found no benefit - possibly because losing weight and keeping it off is difficult, Lichtenfeld said.
Regardless, the society does recommend maintaining a healthy body weight. After all, cutting pounds is a proven aid for other illnesses like diabetes and heart disease. Lichtenfeld calls it "just good common sense." interesting 本人已认领该文编译，48小时后若未提交译文，请其他战友自由认领。
Study: Leaner mice able to fight tumors
研究：脂肪少的小鼠具有抗肿瘤能力
By LAURAN NEERGAARD
AP MEDICAL WRITER
WASHINGTON -- Fatty tissue may decrease the body's ability to kill off cancer, says a study that found making mice leaner - through exercise or surgery - seemed to help them fight skin tumors.
华盛顿——一项研究发现，通过锻炼或手术使小鼠变瘦似乎能帮助它们抵御皮肤癌,于是提出:脂肪组织可能降低机体杀伤肿瘤的能力。
Scientists have long known that people who are overweight are at increased risk of certain types of cancer. The question is why, and whether slimming down will lower that risk or do any good after a tumor forms.
长期以来科学家都清楚，超重者患某特定肿瘤的危险增加。问题在于为什么如此，以及减轻体重是否将降低此风险或对抑制肿瘤的产生起什么积极作用。
Rutgers University scientists took a closer look at that question using mice engineered to get skin cancer, and reported Monday that fat cells may secrete substances that short-circuit one of the body's main anti-tumor defenses.
Rutgers大学的科学家应用设计患皮肤癌的小鼠进一步研究此问题，并在星期一报导：脂肪细胞可能分泌了某些使机体主要抗肿瘤防御中的一条途径短路的物质。
When cells become genetically damaged - such as the DNA damage caused by the sun's ultraviolet rays - they're supposed to self-destruct. It's a process called apoptosis that helps clear out bad cells before they can grow into tumors.
当细胞出现了遗传损伤，如太阳紫外线造成的DNA损害，这被认为是其自毁。一个被称为凋亡的过程帮助在受损细胞衍变为肿瘤前将其清除。
The Rutgers' team put running wheels in the cages of some laboratory mice. They apparently loved the new toy, logging an estimated 2 to 3 miles a day, estimated professor Allan Conney, director of cancer research in Rutgers' pharmacy school.
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作者:admin@医学,生命科学 2010-11-28 17:11
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