Anticancer Non-narcotic Opium Alkaloid Papaverine Suppresses Human Glioblastoma Cell Growth

Background: Glioblastoma (GBM) is the most aggressive type of primary malignant brain tumour. The interaction between high-mobility group box 1 (HMGB1) and receptor for advanced glycation end-products (RAGE) is important for tumour cell growth. Previously, we identified an anticancer candidate, papaverine, that inhibited the HMGB1-RAGE interaction. Materials and Methods: Our study assessed the anticancer effects of papaverine alone or in combination with temozolomide on U87MG and T98G human GBM cells using clonogenicity assays, as well as in a U87MG xenograft mouse model. The radiosensitizing efficacy of papaverine was measured based on the clonogenicity of T98G cells. Results: Papaverine significantly inhibited the clonogenicity of U87MG and T98G cells. Compared with single treatment, the combination of papaverine and temozolomide more highly suppressed the clonogenicity of T98G cells and delayed tumour growth in the U87MG xenograft mouse model. Furthermore, papaverine increased the radiosensitivity of T98G cells. Conclusion: Papaverine is a potential anticancer drug in GBM treatment.