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Naked mole rats are remarkable in
2 e9 Y; t z" s- Y H7 Ccombining extreme longevity with virtually complete resistance to cancer. Now a
3 h' C2 `3 J% o" `2 u& Bnovel glycosaminoglycan variant that may have evolved to provide the creatures 4 \0 P( q( c+ D* \
with the tough, flexible skin needed for a subterranean lifestyle has been , `" `+ S) j f; s9 x, Z9 D
identified as a key contributor to their cancer resistance. Hyaluronan, or
; i- y+ q5 K2 H0 Khyaluronic acid, is a ubiquitous component of the extracellular matrix. Xiao : v% X# ?/ e3 r2 j+ n
Tian et al. observed that the culture media of naked mole-rat . u5 E b- k* j; X
fibroblasts becomes viscous owing to the accumulation of a thick ‘gooey’ : M+ C7 m2 D% j4 K3 E9 U6 n2 S3 N
substance and identified it as a high-molecular-mass hyaluronan (HMM-HA), more
2 _( X5 u( G4 E! f% B6 r; tthan five times larger than mouse and human equivalents. It accumulates in naked
( K0 N) U- J b* P0 J3 [mole-rat tissues owing to low hyaluronidase activity and a unique form of
. k; B/ e4 T: J1 c% y) shyaluronan synthase 2. HMM-HA acts through the CD44 receptor and removal of 3 _* v. ]% \3 J# c
HMM-HA makes naked mole-rat cells more susceptible to transformation. This
! J' V0 n0 S0 C, | Cunusual model of cancer protection suggests potential new avenues of research 0 `! w( k1 ~1 ~4 v1 o' ]' L
into anticancer and life-extension strategies. Cover: Joel Sartore/National ' I$ l& i2 p2 B! f, m! w
Geographic Image Collection/Alamy
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发表于 2013-7-19 19:33
发表于 2013-7-19 19:42
