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- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
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Naked mole rats are remarkable in ; p5 U2 Y& M# Y
combining extreme longevity with virtually complete resistance to cancer. Now a . Y* T7 q( n n+ m& |# n# g
novel glycosaminoglycan variant that may have evolved to provide the creatures
* ]7 \* {6 O. H- h Rwith the tough, flexible skin needed for a subterranean lifestyle has been 9 Z4 a9 j9 C: t
identified as a key contributor to their cancer resistance. Hyaluronan, or 7 }5 h/ y9 N5 t* c3 L0 P. U3 ^- Q
hyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao ) ?' n/ i" k7 E4 B' ?9 H' f8 c
Tian et al. observed that the culture media of naked mole-rat % W4 i5 K# ]8 z6 ~
fibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’
4 I1 u+ ]6 P3 w' E; T* T( _substance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more / f: T6 X# [# L: U2 a; \) B
than five times larger than mouse and human equivalents. It accumulates in naked # z- S* N" E1 T- Y4 O6 f
mole-rat tissues owing to low hyaluronidase activity and a unique form of 1 C$ v) A. |. r
hyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of
! J4 l. |6 {. ^" fHMM-HA makes naked mole-rat cells more susceptible to transformation. This
8 g1 l) F( u1 ?6 {% R9 y# eunusual model of cancer protection suggests potential new avenues of research # x, ]; G* G- ^
into anticancer and life-extension strategies. Cover: Joel Sartore/National
! m$ D$ M+ Z% w" U8 E" YGeographic Image Collection/Alamy* I) s2 ^. r* w! r' \' ]; T( F' |9 T. K
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发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
