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Naked mole rats are remarkable in ' L1 E2 P( L' r: ?& q) x& V
combining extreme longevity with virtually complete resistance to cancer. Now a
, q; j! `* t3 l- ?- \% znovel glycosaminoglycan variant that may have evolved to provide the creatures * y, Q7 }1 Y3 {$ W6 h+ v
with the tough, flexible skin needed for a subterranean lifestyle has been 3 e. Z+ x2 l) s& F. S2 E( E1 e: H8 ?
identified as a key contributor to their cancer resistance. Hyaluronan, or 9 f4 ?) {3 } N; [% f: ?0 O' X9 u
hyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao & m0 J0 y3 o/ b) R
Tian et al. observed that the culture media of naked mole-rat
- M$ i! w+ i9 q+ k) B3 s: L5 Tfibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’ 9 _/ E$ ]4 Q# t x3 I
substance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more
- G# h* O# s4 ~) Y7 t' ^than five times larger than mouse and human equivalents. It accumulates in naked 7 s+ [, V3 E" W N7 j
mole-rat tissues owing to low hyaluronidase activity and a unique form of
5 A b, P. h' ? ^$ Uhyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of
' S* f% x3 A8 w3 }$ _- {- S3 M" EHMM-HA makes naked mole-rat cells more susceptible to transformation. This
- Y2 x* j3 O( j& m0 Runusual model of cancer protection suggests potential new avenues of research
7 c8 C0 Q$ h! Z o9 Binto anticancer and life-extension strategies. Cover: Joel Sartore/National % U, D$ }3 f% A# u6 x
Geographic Image Collection/Alamy5 ]) n; e. B, t5 p. _& H
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发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
