Effects of cIAP-1, cIAP-2 and XIAP triple knockdown on prostate cancer cell susceptibility to apoptosis, cell survival and proliferation.

Hdl Handle:
http://hdl.handle.net/10147/94206
Title:
Effects of cIAP-1, cIAP-2 and XIAP triple knockdown on prostate cancer cell susceptibility to apoptosis, cell survival and proliferation.
Authors:
Gill, Catherine; Dowling, Catherine; O'Neill, Amanda J; Watson, R William G
Affiliation:
UCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland. cgill@hrb.ie
Citation:
Effects of cIAP-1, cIAP-2 and XIAP triple knockdown on prostate cancer cell susceptibility to apoptosis, cell survival and proliferation. 2009, 8:39 Mol. Cancer
Journal:
Molecular cancer
Issue Date:
2009
URI:
http://hdl.handle.net/10147/94206
DOI:
10.1186/1476-4598-8-39
PubMed ID:
19549337
Abstract:
BACKGROUND: Manipulating apoptotic resistance represents an important strategy for the treatment of hormone refractory prostate cancer. We hypothesised that the Inhibitor of Apoptosis (IAP) Proteins may be mediating this resistance and knockdown of cIAP-1, cIAP-2 and XIAP would increase sensitivity to apoptosis. METHODS: cIAP-1, cIAP-2 and XIAP where knocked down either individually or in combination using siRNA in androgen independent prostate cancer PC-3 cells as confirmed by real-time PCR and western blotting. Cells were then treated with TRAIL, Etoposide, or Tunicamycin, and apoptosis assessed by PI DNA staining. Apoptosis was confirmed with Annexin V labelling and measurement of PARP cleavage, and was inhibited using the pan-caspase inhibitor, zVAD.fmk. Clonogenic assays and assessment of ID-1 expression by western blotting were used to measure recovery and proliferation. RESULTS: PC-3 are resistant to TRAIL induced apoptosis and have elevated expression of cIAP-1, cIAP-2 and XIAP. Combined knockdown sensitised PC-3 to TRAIL induced apoptosis, but not to Etoposide or Tunicmycin, with corresponding increases in caspase activity and PARP cleavage which was inhibited by ZVAD.fmk. Triple knock down decreased proliferation which was confirmed by decreased ID-1 expression. CONCLUSION: Simultaneous knock down of the IAPs not only sensitised the PC-3 to TRAIL but also inhibited their proliferation rates and clonogenic survival. The inability to alter sensitivity to other triggers of apoptosis suggests that this effect is specific for death receptor pathways and knock down might facilitate immune-surveillance mechanisms to counter cancer progression and, in combination with therapeutic approaches using TRAIL, could represent an important treatment strategy.
Language:
en
MeSH:
Apoptosis; Cell Line, Tumor; Cell Proliferation; Cell Survival; Data Interpretation, Statistical; Etoposide; Gene Expression; Gene Knockdown Techniques; Humans; Inhibitor of Apoptosis Proteins; Male; Peptide Hydrolases; Prostatic Neoplasms; RNA, Small Interfering; TNF-Related Apoptosis-Inducing Ligand; Tunicamycin; X-Linked Inhibitor of Apoptosis Protein
ISSN:
1476-4598

Full metadata record

DC FieldValue Language
dc.contributor.authorGill, Catherineen
dc.contributor.authorDowling, Catherineen
dc.contributor.authorO'Neill, Amanda Jen
dc.contributor.authorWatson, R William Gen
dc.date.accessioned2010-03-12T15:44:12Z-
dc.date.available2010-03-12T15:44:12Z-
dc.date.issued2009-
dc.identifier.citationEffects of cIAP-1, cIAP-2 and XIAP triple knockdown on prostate cancer cell susceptibility to apoptosis, cell survival and proliferation. 2009, 8:39 Mol. Canceren
dc.identifier.issn1476-4598-
dc.identifier.pmid19549337-
dc.identifier.doi10.1186/1476-4598-8-39-
dc.identifier.urihttp://hdl.handle.net/10147/94206-
dc.description.abstractBACKGROUND: Manipulating apoptotic resistance represents an important strategy for the treatment of hormone refractory prostate cancer. We hypothesised that the Inhibitor of Apoptosis (IAP) Proteins may be mediating this resistance and knockdown of cIAP-1, cIAP-2 and XIAP would increase sensitivity to apoptosis. METHODS: cIAP-1, cIAP-2 and XIAP where knocked down either individually or in combination using siRNA in androgen independent prostate cancer PC-3 cells as confirmed by real-time PCR and western blotting. Cells were then treated with TRAIL, Etoposide, or Tunicamycin, and apoptosis assessed by PI DNA staining. Apoptosis was confirmed with Annexin V labelling and measurement of PARP cleavage, and was inhibited using the pan-caspase inhibitor, zVAD.fmk. Clonogenic assays and assessment of ID-1 expression by western blotting were used to measure recovery and proliferation. RESULTS: PC-3 are resistant to TRAIL induced apoptosis and have elevated expression of cIAP-1, cIAP-2 and XIAP. Combined knockdown sensitised PC-3 to TRAIL induced apoptosis, but not to Etoposide or Tunicmycin, with corresponding increases in caspase activity and PARP cleavage which was inhibited by ZVAD.fmk. Triple knock down decreased proliferation which was confirmed by decreased ID-1 expression. CONCLUSION: Simultaneous knock down of the IAPs not only sensitised the PC-3 to TRAIL but also inhibited their proliferation rates and clonogenic survival. The inability to alter sensitivity to other triggers of apoptosis suggests that this effect is specific for death receptor pathways and knock down might facilitate immune-surveillance mechanisms to counter cancer progression and, in combination with therapeutic approaches using TRAIL, could represent an important treatment strategy.-
dc.language.isoenen
dc.subject.meshApoptosis-
dc.subject.meshCell Line, Tumor-
dc.subject.meshCell Proliferation-
dc.subject.meshCell Survival-
dc.subject.meshData Interpretation, Statistical-
dc.subject.meshEtoposide-
dc.subject.meshGene Expression-
dc.subject.meshGene Knockdown Techniques-
dc.subject.meshHumans-
dc.subject.meshInhibitor of Apoptosis Proteins-
dc.subject.meshMale-
dc.subject.meshPeptide Hydrolases-
dc.subject.meshProstatic Neoplasms-
dc.subject.meshRNA, Small Interfering-
dc.subject.meshTNF-Related Apoptosis-Inducing Ligand-
dc.subject.meshTunicamycin-
dc.subject.meshX-Linked Inhibitor of Apoptosis Protein-
dc.titleEffects of cIAP-1, cIAP-2 and XIAP triple knockdown on prostate cancer cell susceptibility to apoptosis, cell survival and proliferation.en
dc.contributor.departmentUCD School of Medicine and Medical Science, University College Dublin, Dublin, Ireland. cgill@hrb.ieen
dc.identifier.journalMolecular canceren

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