|
- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
|
7 S, c( }7 T4 R7 H+ G3 m' B% z. E8 U# `( n% R4 t% {
Naked mole rats are remarkable in
8 s) `6 f6 O( o5 d# X0 |combining extreme longevity with virtually complete resistance to cancer. Now a ( R/ y4 C6 ~5 P; o9 V$ H
novel glycosaminoglycan variant that may have evolved to provide the creatures
, |$ C, v j4 G! Z- ?5 W7 d7 Uwith the tough, flexible skin needed for a subterranean lifestyle has been $ v% U9 H; Z- s! j
identified as a key contributor to their cancer resistance. Hyaluronan, or $ {; v" V: `- A9 |; D
hyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao
5 M0 ?9 w' Q" Z. yTian et al. observed that the culture media of naked mole-rat
5 w5 t) m( x' @- L$ Cfibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’
d- O a, v4 e4 k& A6 T3 S Z s% Csubstance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more 1 Z+ Q0 X# V3 A N* h3 {
than five times larger than mouse and human equivalents. It accumulates in naked 5 \+ C. k8 J9 V/ e2 H
mole-rat tissues owing to low hyaluronidase activity and a unique form of ' y0 `3 f8 |6 X2 |
hyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of 9 {: @4 ~) f. n* z
HMM-HA makes naked mole-rat cells more susceptible to transformation. This 7 w2 E* @7 n: V, ?( n/ q5 X
unusual model of cancer protection suggests potential new avenues of research 5 f& ], { A+ h" ^* o
into anticancer and life-extension strategies. Cover: Joel Sartore/National * `) i. |1 F, ]6 ~5 G: r
Geographic Image Collection/Alamy
9 x/ R; ?+ c: K |
-
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
