Abstract | PURPOSE: EXPERIMENTAL DESIGN: A xenograft model in nude mice was used to determine pancreatic cancer tumorigenesis and therapeutic efficacy of TRA-8, a monoclonal agonistic antibody for DR5. Pancreatic cancer cells were used to characterize mechanisms underlying PARP-1 regulation of TRA-8-induced apoptosis in vitro. RESULTS: PARP-1 was found highly expressed in the TRA-8-resistant PANC-1 and Suit-2 cells, compared with TRA-8-sensitive BxPc-3 and MiaPaca-2. Inhibition of PARP-1 with a pharmacologic inhibitor sensitized PANC-1 and Suit2 cells to TRA-8-induced apoptosis in a dose-dependent manner. Furthermore, siRNAs specifically knocking down PARP-1 markedly enhanced TRA-8-induced apoptosis in vitro and augmented the efficacy of TRA-8 therapy on tumorigenesis in vivo. PARP-1 knockdown increased TRA-8-induced activation of caspase-8 in the death-induced signaling complex (DISC). Immunoprecipitation with DR5 antibody identified the recruitment of PARP-1 and PARP-1-mediated protein poly-ADP-ribosylation (pADPr) modification in the DR5-associated DISC. Further characterization revealed that PARP-1-mediated pADPr modification of caspase-8 inhibited caspase-8 activation, which may contribute to its function in regulating TRA-8 resistance. CONCLUSIONS: Our studies provide molecular insights into a novel function of PARP-1 in regulating the extrinsic apoptosis machinery and also support interventions combining PARP-1 inhibitors with DR agonists for pancreatic cancer therapy.
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Authors | Kaiyu Yuan, Yong Sun, Tong Zhou, Jay McDonald, Yabing Chen |
Journal | Clinical cancer research : an official journal of the American Association for Cancer Research
(Clin Cancer Res)
Vol. 19
Issue 17
Pg. 4750-9
(Sep 01 2013)
ISSN: 1557-3265 [Electronic] United States |
PMID | 23833311
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
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Copyright | ©2013 AACR. |
Chemical References |
- Antibodies, Monoclonal
- Poly(ADP-ribose) Polymerase Inhibitors
- Receptors, TNF-Related Apoptosis-Inducing Ligand
- TNF-Related Apoptosis-Inducing Ligand
- Tnfsf10 protein, mouse
- Parp1 protein, mouse
- Poly (ADP-Ribose) Polymerase-1
- Poly(ADP-ribose) Polymerases
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Topics |
- Animals
- Antibodies, Monoclonal
(administration & dosage, immunology)
- Apoptosis
(genetics)
- Carcinogenesis
(immunology)
- Drug Resistance, Neoplasm
(genetics)
- Gene Knockdown Techniques
- Humans
- Mice
- Pancreatic Neoplasms
(drug therapy, immunology)
- Poly (ADP-Ribose) Polymerase-1
- Poly(ADP-ribose) Polymerase Inhibitors
- Poly(ADP-ribose) Polymerases
(genetics, immunology)
- Receptors, TNF-Related Apoptosis-Inducing Ligand
(immunology)
- TNF-Related Apoptosis-Inducing Ligand
(genetics, immunology)
- Xenograft Model Antitumor Assays
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