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- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
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Naked mole rats are remarkable in
. N2 m# d- ?% [5 Lcombining extreme longevity with virtually complete resistance to cancer. Now a - P- X+ g% t3 T$ ?" y; Q
novel glycosaminoglycan variant that may have evolved to provide the creatures
. ^- v o4 P* v5 M# ^: cwith the tough, flexible skin needed for a subterranean lifestyle has been Y( O! Z. p2 D0 L
identified as a key contributor to their cancer resistance. Hyaluronan, or ! T1 i; Q: Z- j* S3 U2 B$ {3 B4 P
hyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao , }# H+ A- C- A9 |# i4 T0 z) U
Tian et al. observed that the culture media of naked mole-rat
4 ]( x- G8 h6 xfibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’
5 `/ ~5 G2 Q' u% bsubstance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more 9 ~2 A! g l" H, U( A
than five times larger than mouse and human equivalents. It accumulates in naked & u7 J2 U& K$ o5 B% a7 M0 S, k
mole-rat tissues owing to low hyaluronidase activity and a unique form of
" R: X1 i/ F- N! N ohyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of
3 D, Z" R$ g2 z0 Y$ t' oHMM-HA makes naked mole-rat cells more susceptible to transformation. This % _7 _8 u8 ~ P2 W% d1 V8 H
unusual model of cancer protection suggests potential new avenues of research , d( p- o; e G4 K# x0 Q
into anticancer and life-extension strategies. Cover: Joel Sartore/National
" k1 m0 x0 Y& d. @/ X/ Y3 A# mGeographic Image Collection/Alamy' Q: X9 `- b/ ]% n6 D" G' f- C
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总评分: 威望 + 20
包包 + 20
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发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
