Telomerase-specific virotherapy for human squamous cell carcinoma

BACKGROUND: Replication-selective tumor-specific viruses present a novel approach for treatment of neoplastic disease. They are designed to induce lysis after propagation within the tumor. Human telomerase is active in over 85% of primary cancers and its activity correlates closely with human telomerase reverse transcriptase (hTERT) expression. OBJECTIVES: Oncolytic viruses, Telomelysin and TelomeScan, that combine the specificity of hTERT promoter-based expression systems with the lytic efficacy of replicative viruses were developed. The goal was to confirm the efficacy of the viruses for human squamous cell carcinoma. RESULTS/CONCLUSION: Squamous cell carcinoma of the head and neck (SCCHN) is characterized by locoregional spread, and is clinically accessible, making it an attractive target for intratumoral virotherapy. The viruses replicated efficiently and induced killing in a panel of human cancer cell lines including SCCHN cells in vitro and in vivo. These results illustrate the potential of telomerase-specific oncolytic viruses for treatment of human SCCHN.