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- 26159
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Naked mole rats are remarkable in 1 O+ _: T8 G' G! I$ P* ?
combining extreme longevity with virtually complete resistance to cancer. Now a
0 F" ~5 ^ M/ T/ ~9 Dnovel glycosaminoglycan variant that may have evolved to provide the creatures
) _5 A& V, z0 N8 Y6 dwith the tough, flexible skin needed for a subterranean lifestyle has been ; i8 Y: \: |( ]( A' V
identified as a key contributor to their cancer resistance. Hyaluronan, or
8 j" e$ l7 u# O* J$ ]hyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao " \5 q! P6 Q5 a3 Z% i& K$ D
Tian et al. observed that the culture media of naked mole-rat
$ y7 C f/ [% B2 X/ Z+ I4 l3 `( n/ zfibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’ , \$ x5 G/ v( x& y( p" H
substance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more
1 A3 V! W) F5 H- I: Z% B% wthan five times larger than mouse and human equivalents. It accumulates in naked
1 q) e5 t) Z4 t0 \! H9 }2 kmole-rat tissues owing to low hyaluronidase activity and a unique form of
9 }; T+ d4 I: v2 \; X) bhyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of & E a' U4 Y1 R' N$ t4 D4 H
HMM-HA makes naked mole-rat cells more susceptible to transformation. This
! n/ Y. [) W, Y+ t8 l s0 J, f! Gunusual model of cancer protection suggests potential new avenues of research ; x$ c. B7 z2 Z
into anticancer and life-extension strategies. Cover: Joel Sartore/National 2 g5 O' G8 Q6 n' S( W! p) y
Geographic Image Collection/Alamy
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发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
