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- 积分
- 17983
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- 17983
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- 26159
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; S% J, U0 F5 ]& oNaked mole rats are remarkable in / M, A$ d+ h- _2 b; Q" L
combining extreme longevity with virtually complete resistance to cancer. Now a
4 A. t, \' X) Znovel glycosaminoglycan variant that may have evolved to provide the creatures 0 Y/ k- ]! p0 s* W# q
with the tough, flexible skin needed for a subterranean lifestyle has been 1 m3 E& H. C1 Z- [" T9 p
identified as a key contributor to their cancer resistance. Hyaluronan, or
2 B3 N6 Z9 O' P, P+ O- Chyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao # M& l( s' Z" @# e
Tian et al. observed that the culture media of naked mole-rat
6 c1 j6 }# G1 yfibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’
- \- O$ S% }& j5 `2 Tsubstance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more $ `4 ^' d8 b0 B6 m4 ^ t+ }1 ?7 Q6 q
than five times larger than mouse and human equivalents. It accumulates in naked 3 t/ H, z% U5 K& H3 Q
mole-rat tissues owing to low hyaluronidase activity and a unique form of 5 e9 Q! l* v. u f. w) z
hyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of
( f! O# A- f: c! `* W7 \' mHMM-HA makes naked mole-rat cells more susceptible to transformation. This ) z& i- ]2 l* W9 \ }. I p
unusual model of cancer protection suggests potential new avenues of research - h, p, q; h' j: U8 n
into anticancer and life-extension strategies. Cover: Joel Sartore/National 4 l' z7 U/ \2 M% m
Geographic Image Collection/Alamy
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发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
