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- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
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Naked mole rats are remarkable in
: x% ]! z6 L1 T, T9 Jcombining extreme longevity with virtually complete resistance to cancer. Now a
! W5 w. K) S8 B5 Dnovel glycosaminoglycan variant that may have evolved to provide the creatures
0 m7 O% |9 \5 g' T3 iwith the tough, flexible skin needed for a subterranean lifestyle has been . y0 R& c) ?; n( L# s
identified as a key contributor to their cancer resistance. Hyaluronan, or , ~% `( E+ R/ r7 z- o
hyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao ' j4 O) {) }. ]- |
Tian et al. observed that the culture media of naked mole-rat " ~; B! R. E- z7 H' i3 m5 u( Z! m
fibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’
. d7 d: B; @% bsubstance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more
! f H$ Q# c; o1 T4 xthan five times larger than mouse and human equivalents. It accumulates in naked + \9 \2 x7 [: B1 j" r0 t7 K" d& T
mole-rat tissues owing to low hyaluronidase activity and a unique form of : H2 c: V, I z; c% B
hyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of 5 N$ v" `1 O2 j+ u6 g* d' }# a0 c0 Z
HMM-HA makes naked mole-rat cells more susceptible to transformation. This $ d- Y0 T, ?# R: ~) d7 k
unusual model of cancer protection suggests potential new avenues of research ' Y' @( c" P7 g2 x, I% c
into anticancer and life-extension strategies. Cover: Joel Sartore/National $ z# x. K- N% B2 ^5 C
Geographic Image Collection/Alamy' e Y5 C ]8 I9 a+ h$ i
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总评分: 威望 + 20
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发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
