An investigation into the effect of apoptosis-inducing agents on SCC head and neck cancer

Abstract

Problem: The purpose of this study was to investigate the effects of known apoptosis-inducing agents on UM-SCC head and neck cancer cell lines. Of specific interest was the effect of FasL-expressing adenovirus (AdGFPFasLTET) (Hyer et al, 2000, Molecular Therapy 2: 348–58 [ref.12]) and the acid ceramidase inhibitor LCL204. Methods: UM-SCC-1 cells were treated with AdGFPFasLTET and LCL204 separately and combined in a time course and dose response where cell cytotoxicity and apoptotic protein expression levels were measured by MTS cytotoxicity assay and Western Blot analysis. Results: MTS assay shows LCL204 and AdGFPFasLTET cause dose- and time-dependent cell death. UM-SCC-1 are also sensitive to doxorubicin, cisplatin, and SNP Nitric Oxide donors. 200MOI AdGFPFasLTET at 48 hours shows 65% cytotoxicity and 10uM LCL204 shows 95% cytotoxicity at 24 hours. Conclusion: Pretreatment with 2 uM LCL204 for 24 hours sensitizes cells to both AdGFPFasLTET and doxorubicin creating a synergistic effect. Preliminary Western Blot analysis shows that UM-SCC-1 is sensitive to AdGFPFasLTET by initiation of the Fas-mediated apoptotic pathway including caspase-8 activation, bid cleavage, c-FLIP long cleavage, PARP cleavage, and survivin down regulation. The role of LCL204 on UM-SCC-1 cells in apoptotic cell death is currently being explored. Significance: These data suggest that the acid ceramidase inhibitor LCL204 holds potential as a novel chemotherapeutic agent in the treatment of head and neck tumors. Support: Supported by the Basic and Preclinical Therapeutics program of the Hollings Cancer Center.