TY - JOUR
T1 - Redox regulation in stem-like cancer cells by CD44 variant isoforms
AU - Nagano, O.
AU - Okazaki, S.
AU - Saya, H.
PY - 2013/10/31
Y1 - 2013/10/31
N2 - Increasing evidence indicates that several types of solid tumor are hierarchically organized and sustained by a distinct population of cancer stem cells (CSCs). CSCs possess enhanced mechanisms of protection from stress induced by reactive oxygen species (ROS) that render them resistant to chemo-and radiotherapy. Expression of CD44, especially variant isoforms (CD44v) of this major CSC marker, contributes to ROS defense through upregulation of the synthesis of reduced glutathione (GSH), the primary intracellular antioxidant. CD44v interacts with and stabilizes xCT, a subunit of the cystine-glutamate transporter xc(-), and thereby promotes cystine uptake for GSH synthesis. Given that cancer cells are often exposed to high levels of ROS during tumor progression, the ability to avoid the consequences of such exposure is required for cancer cell survival and propagation in vivo. CSCs, in which defense against ROS is enhanced by CD44v are thus thought to drive tumor growth, chemoresistance and metastasis. Therapy targeted to the CD44v-xCT system may therefore impair the ROS defense ability of CSCs and thereby sensitize them to currently available treatments.
AB - Increasing evidence indicates that several types of solid tumor are hierarchically organized and sustained by a distinct population of cancer stem cells (CSCs). CSCs possess enhanced mechanisms of protection from stress induced by reactive oxygen species (ROS) that render them resistant to chemo-and radiotherapy. Expression of CD44, especially variant isoforms (CD44v) of this major CSC marker, contributes to ROS defense through upregulation of the synthesis of reduced glutathione (GSH), the primary intracellular antioxidant. CD44v interacts with and stabilizes xCT, a subunit of the cystine-glutamate transporter xc(-), and thereby promotes cystine uptake for GSH synthesis. Given that cancer cells are often exposed to high levels of ROS during tumor progression, the ability to avoid the consequences of such exposure is required for cancer cell survival and propagation in vivo. CSCs, in which defense against ROS is enhanced by CD44v are thus thought to drive tumor growth, chemoresistance and metastasis. Therapy targeted to the CD44v-xCT system may therefore impair the ROS defense ability of CSCs and thereby sensitize them to currently available treatments.
KW - CD44
KW - cancer stem cell
KW - cystine-glutamate transporter
KW - reactive oxygen species
UR - http://www.scopus.com/inward/record.url?scp=84887043495&partnerID=8YFLogxK
U2 - 10.1038/onc.2012.638
DO - 10.1038/onc.2012.638
M3 - Review article
C2 - 23334333
AN - SCOPUS:84887043495
SN - 0950-9232
VL - 32
SP - 5191
EP - 5198
JO - Oncogene
JF - Oncogene
IS - 44
ER -