Telomerase confers resistance to caspase-mediated apoptosis.
There is growing evidence that accelerated telomeric attrition and/or aberrant telomerase activity contributes to pathogenesis in a number of diseases. Likewise, there is increasing interest to develop new therapies to restore or replace dysfunctional cells characterized by short telomeric length using telomerase-positive counterparts or stem cells. While telomerase adds telomeric repeats de novo contributing to enhanced proliferative capacity and lifespan, it may also increase cellular survival by conferring resistance to apoptosis. Consequently, we sought to determine the involvement of telomerase for reduced apoptosis using ovarian surface epithelial cells. We found that expression of hTERT, the catalytic component of telomerase, was sufficient and specific to reduce caspase-mediated cellular apoptosis. Further, hTERT expression reduced activation of caspases 3, 8, and 9, reduced expression of pro-apoptotic mitochondrial proteins t-BID, BAD, and BAX and increased expression of the anti-apoptotic mitochondrial protein, Bcl-2. The ability of telomerase to suppress caspase-mediated apoptosis was p-jnk dependent since abrogation of jnk expression with jip abolished resistance to apoptosis. Consequently, these findings indicate that telomerase may promote cellular survival in epithelial cells by suppressing jnk-dependent caspase-mediated apoptosis.
Bermudez
Yira
Y
Department of Pathology, University of South Florida and the H Lee Moffitt Cancer Center, Tampa, FL 33612, USA.
Erasso
Diana
D
Johnson
Nicole C
NC
Alfonso
Michelle Y
MY
Lowell
Nancy E
NE
Kruk
Patricia A
PA
D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism*; D002460:Cell Line; D049109:Cell Proliferation; D002470:Cell Survival; D004591:Electrophoresis, Polyacrylamide Gel; D004847:Epithelial Cells / Q000166:cytology / Q000201:enzymology; D006801:Humans; D010446:Peptide Fragments / Q000096:biosynthesis / Q000235:genetics; D019098:Telomerase / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology*; D016615:Telomere / Q000648:ultrastructure
D010446:Peptide Fragments; D019098:Telomerase; D020169:Caspases