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- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
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6 o7 r8 s3 n+ Y4 m' M% PNaked mole rats are remarkable in ; a. C7 \% e8 `/ e0 Q
combining extreme longevity with virtually complete resistance to cancer. Now a - P: p( S2 L1 t: b1 w
novel glycosaminoglycan variant that may have evolved to provide the creatures
% g$ Q7 E& ]. t' H: ywith the tough, flexible skin needed for a subterranean lifestyle has been 9 a5 t. P1 O5 E9 p& T/ p _( Z1 }' f
identified as a key contributor to their cancer resistance. Hyaluronan, or 3 Q+ I6 G7 h" p: o% i
hyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao % s( D7 H, v3 p; V! M) i: U
Tian et al. observed that the culture media of naked mole-rat
. b( W& E1 Y: c5 W( X+ o# R1 Yfibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’ _5 E2 I( H1 z* ^
substance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more
: b R) e3 N! M$ N! i) X+ zthan five times larger than mouse and human equivalents. It accumulates in naked 9 N ^' ^; L% z: _% N
mole-rat tissues owing to low hyaluronidase activity and a unique form of
) g1 j5 Z1 c" Q4 b) F! h1 G7 |hyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of 7 E# C7 N+ } E7 j- N
HMM-HA makes naked mole-rat cells more susceptible to transformation. This 7 i1 u1 r0 [& S3 i/ K! _. v1 w1 @
unusual model of cancer protection suggests potential new avenues of research + t" N; ?" T+ i0 G7 l+ s
into anticancer and life-extension strategies. Cover: Joel Sartore/National
# ^' n: b1 ~( H7 G/ I# lGeographic Image Collection/Alamy. N W+ m- a# T# |" ^
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发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
