|
- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
|
 3 K) V7 v3 B6 P( R& ^$ |* B
2 f! e$ _4 U2 J3 z
Naked mole rats are remarkable in 0 D4 o1 \% [# B& o6 i! W% I& X
combining extreme longevity with virtually complete resistance to cancer. Now a ) q9 \0 j: I* V+ q6 v g
novel glycosaminoglycan variant that may have evolved to provide the creatures
0 X" A) u9 _% p3 r; qwith the tough, flexible skin needed for a subterranean lifestyle has been ' k0 V) J- g8 \0 O j( N6 j
identified as a key contributor to their cancer resistance. Hyaluronan, or , B5 r) T0 a- ~; \' U
hyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao
+ e' d( D1 W, @1 ?1 |3 Y8 A. W) L" D$ |Tian et al. observed that the culture media of naked mole-rat
; h5 `0 S: L$ s6 u9 @fibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’
) w7 Z, [8 c2 c8 q- Y }* R( ^& usubstance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more
. Q0 o* N7 ]! J) X: g( ~5 sthan five times larger than mouse and human equivalents. It accumulates in naked : v5 K1 z& P S9 ]0 j4 R
mole-rat tissues owing to low hyaluronidase activity and a unique form of C( X8 T4 i! V% ]' y( \
hyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of
& X, d# O" ^4 b( N6 a, UHMM-HA makes naked mole-rat cells more susceptible to transformation. This ; a' c6 c. m; s. f; C# z- @, T
unusual model of cancer protection suggests potential new avenues of research
' O- g) n z) Z$ linto anticancer and life-extension strategies. Cover: Joel Sartore/National
9 ^8 j; C' q# M% q. T1 j% ]6 gGeographic Image Collection/Alamy
' |6 b+ F, w7 t) W* U( O |
-
总评分: 威望 + 20
包包 + 20
查看全部评分
|
发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
