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- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
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 : o: r" g, c. F9 |0 C# o2 v
& f* N6 b: i f; z- a2 PNaked mole rats are remarkable in
6 I K* S4 u# h5 D4 K0 Dcombining extreme longevity with virtually complete resistance to cancer. Now a
0 i$ W" ~% _ Lnovel glycosaminoglycan variant that may have evolved to provide the creatures 7 G5 r5 p6 C/ H0 f0 G+ o& t- W/ e
with the tough, flexible skin needed for a subterranean lifestyle has been - @# W7 k7 r( ~# t
identified as a key contributor to their cancer resistance. Hyaluronan, or
8 ^$ l! A& _3 i7 Mhyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao 4 D& Y$ M! [3 U% K
Tian et al. observed that the culture media of naked mole-rat ; s0 m* K2 a1 k) M7 L' ^9 X
fibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’
- ~- I- u8 B* Ksubstance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more
4 E) Z4 N _& cthan five times larger than mouse and human equivalents. It accumulates in naked . }& G8 ~; `2 W- Y, s
mole-rat tissues owing to low hyaluronidase activity and a unique form of
( U$ d# z+ e) |% k0 f9 ahyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of 4 q3 b" q4 H; g$ _! K
HMM-HA makes naked mole-rat cells more susceptible to transformation. This & [9 _7 c. C% F
unusual model of cancer protection suggests potential new avenues of research
) i& Q1 N- i8 Y# X% e2 n* t9 Pinto anticancer and life-extension strategies. Cover: Joel Sartore/National + Y& O& v. M4 Z) K& m6 B( d6 B3 m. {
Geographic Image Collection/Alamy" C. q4 }8 m: P1 Q: Y% F( W
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发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
