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- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
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; p) h/ ~" x% MNaked mole rats are remarkable in 6 r! v7 D5 x. B5 k1 P% @4 H+ S E
combining extreme longevity with virtually complete resistance to cancer. Now a ' z+ r* U8 |) @6 `# `% @/ P- f
novel glycosaminoglycan variant that may have evolved to provide the creatures % \4 b) G5 u0 p+ S
with the tough, flexible skin needed for a subterranean lifestyle has been
# m/ U6 Z" E' k: Hidentified as a key contributor to their cancer resistance. Hyaluronan, or
R; ~4 Z' Y; C# M+ dhyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao
; v7 e, I; u6 l( ?: X8 w1 [Tian et al. observed that the culture media of naked mole-rat
: p8 N* T$ \1 D: P6 e3 gfibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’
8 ?" \& g2 m E& Esubstance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more . c+ v- k5 R3 P& v1 {
than five times larger than mouse and human equivalents. It accumulates in naked
) G' J2 Q5 B; P- `( p$ r h0 Omole-rat tissues owing to low hyaluronidase activity and a unique form of : ^ ]1 q0 B" L2 A; J
hyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of
: @1 ~4 W$ U( I2 S0 [HMM-HA makes naked mole-rat cells more susceptible to transformation. This
% S' D1 R3 M# k& P3 Kunusual model of cancer protection suggests potential new avenues of research 6 m* ]3 E% Q8 P( b. I5 |
into anticancer and life-extension strategies. Cover: Joel Sartore/National
5 v0 e- ?9 M0 P* `3 \9 K9 uGeographic Image Collection/Alamy$ D. M9 f5 c8 a+ d
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发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
