Tumours with elevated levels of the Notch and Wnt pathways exhibit efficacy to PF-03084014, a γ-secretase inhibitor, in a preclinical colorectal explant model.
Br J Cancer 2013;
109:667-75. [PMID:
23868008 PMCID:
PMC3738122 DOI:
10.1038/bjc.2013.361]
[Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/14/2013] [Accepted: 06/17/2013] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND
Dysregulation of the Notch pathway has been identified to play an important role in the development and progression of colorectal cancer (CRC). In this study, we used a patient-derived CRC explant model to investigate the efficacy of the clinical γ-secretase inhibitor (GSI) PF-03084014.
METHODS
A total of 16 CRC explants were treated with PF-03084014. Knockdown of RBPjκ gene was used to determine the specificity of PF-03084014. Evaluation of the Notch and Wnt pathways in CRC explant tumours was performed by gene array and immunoblotting.
RESULTS
We identified a subset of CRC tumours that exhibited elevations of the Notch and Wnt pathways sensitive to PF-03084014. Treatment with the GSI resulted in a significant reduction in cleaved Notch, Axin2 (Wnt-dependent gene) and active β-catenin. In addition, knockdown of the RBPjκ gene showed that PF-03084014 has specificity for the Notch pathway in an HCT116 cell line xenograft model. Finally, an increase in apoptosis was observed in CRC001- and CRC021-sensitive tumours.
CONCLUSION
This study provides evidence that inhibition of γ-secretase may be beneficial in a subset of patients with elevated levels of the Wnt and Notch pathways.
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