Liu J, Kuo WL, Seiwert TY, Lingen M, Ciaccio MF, Jones RB, Rosner MR, Cohen EEW. Effect of complementary pathway blockade on efficacy of combination enzastaurin and rapamycin.
Head Neck 2011;
33:1774-82. [PMID:
21438065 DOI:
10.1002/hed.21701]
[Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2010] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND
Rapamycin is an mTOR inhibitor with preclinical efficacy in squamous cell carcinoma of the head and neck (SCCHN). However, mTOR inhibitors also increase Akt activity in SCCHN cell lines, which would promote survival and oncogenesis. Enzastaurin is an AGC kinase inhibitor with nanomolar inhibitory concentrations for Akt and protein kinase C (PKC). Moreover, Akt and PKC inhibitors have demonstrated efficacy in SCCHN.
METHODS
We hypothesized that the combination of rapamycin and enzastaurin would be more effective than either agent alone.
RESULTS
Rapamycin and enzastaurin generally inhibited putative targets in SCCHN cell lines in culture. In mice xenografted with CAL27 cells, rapamycin and enzastaurin produced growth delay. In contrast, the combination of rapamycin and enzastaurin caused regression of CAL27 tumors with evidence of inhibition of putative targets, survival, angiogenesis and proliferation.
CONCLUSION
These data demonstrate that the combination of rapamycin and enzastaurin disrupts critical oncogenic pathways in SCCHN and has efficacy in preclinical models.
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