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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2011-5-17
pubmed:abstractText
Autophagy is an evolutionarily conserved stress response mechanism that often occurs in apoptosis-defective cancer cells and can protect against cell death. In this study, we investigated how apoptosis and autophagy affect each other in cancer cells in response to chemotherapeutic treatment. We found that specific ablation of the proapoptotic function of cytochrome c, a key regulator of mitochondria-mediated apoptosis, enhanced autophagy following chemotherapeutic treatment. Induction of autophagy required Beclin 1 and was associated with blockage of Beclin 1 cleavage by caspase 8 at two sites. To investigate the role of Beclin 1 cleavage in the suppression of autophagy and cell survival, a caspase-resistant mutant of Beclin 1 was knocked into HCT116 colon cancer cells. Beclin 1 mutant knockin resulted in markedly increased autophagy and improved long-term cell survival after chemotherapeutic treatment but without affecting apoptosis and caspase activation. Furthermore, Beclin 1 mutant tumors were significantly less responsive to chemotherapeutic treatment than were wild-type tumors. These results show that chemotherapy-induced apoptosis inhibits autophagy at the execution stage subsequent to cytochrome c release through caspase 8-mediated cleavage of Beclin 1. If apoptosis fails to execute, autophagy is unleashed due to lack of Beclin 1 cleavage by caspases and can contribute to cancer cell survival and therapeutic resistance. Therefore, Beclin 1 may be a useful target for inhibiting autophagy to sensitize chemotherapy.
pubmed:grant
http://linkedlifedata.com/resource/pubmed/grant/CA047904, http://linkedlifedata.com/resource/pubmed/grant/CA106348, http://linkedlifedata.com/resource/pubmed/grant/CA121105, http://linkedlifedata.com/resource/pubmed/grant/CA129829, http://linkedlifedata.com/resource/pubmed/grant/CA132385, http://linkedlifedata.com/resource/pubmed/grant/CA148629, http://linkedlifedata.com/resource/pubmed/grant/GM087798, http://linkedlifedata.com/resource/pubmed/grant/P20 CA132385-02, http://linkedlifedata.com/resource/pubmed/grant/P20 CA132385-03, http://linkedlifedata.com/resource/pubmed/grant/R01 CA106348-01, http://linkedlifedata.com/resource/pubmed/grant/R01 CA106348-02, http://linkedlifedata.com/resource/pubmed/grant/R01 CA106348-03, http://linkedlifedata.com/resource/pubmed/grant/R01 CA106348-04, http://linkedlifedata.com/resource/pubmed/grant/R01 CA106348-05, http://linkedlifedata.com/resource/pubmed/grant/R01 CA106348-06A2, http://linkedlifedata.com/resource/pubmed/grant/R01 CA106348-07, http://linkedlifedata.com/resource/pubmed/grant/R01 CA121105-01A1, http://linkedlifedata.com/resource/pubmed/grant/R01 CA121105-02, http://linkedlifedata.com/resource/pubmed/grant/R01 CA121105-03, http://linkedlifedata.com/resource/pubmed/grant/R01 CA121105-03S1, http://linkedlifedata.com/resource/pubmed/grant/R01 CA121105-04, http://linkedlifedata.com/resource/pubmed/grant/R01 CA121105-05, http://linkedlifedata.com/resource/pubmed/grant/R01 CA129829-01A1, http://linkedlifedata.com/resource/pubmed/grant/R01 CA129829-02, http://linkedlifedata.com/resource/pubmed/grant/R01 CA129829-03, http://linkedlifedata.com/resource/pubmed/grant/R01 CA129829-04, http://linkedlifedata.com/resource/pubmed/grant/R01 CA148629-01A1, http://linkedlifedata.com/resource/pubmed/grant/R01 CA148629-02, http://linkedlifedata.com/resource/pubmed/grant/U01 DK085570-01, http://linkedlifedata.com/resource/pubmed/grant/U01 DK085570-02, http://linkedlifedata.com/resource/pubmed/grant/U01 DK085570-02S1, http://linkedlifedata.com/resource/pubmed/grant/U01 DK085570-03, http://linkedlifedata.com/resource/pubmed/grant/U01DK085570
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1538-7445
pubmed:author
pubmed:copyrightInfo
©2011 AACR
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
71
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3625-34
pubmed:dateRevised
2011-9-26
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Following cytochrome c release, autophagy is inhibited during chemotherapy-induced apoptosis by caspase 8-mediated cleavage of Beclin 1.
pubmed:affiliation
Department of Pharmacology and Chemical Biology, University of Pittsburgh Cancer Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
pubmed:publicationType
Journal Article
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