Introduction

Oral melanoma is one of the most common malignant tumors in the oral cavity in dogs. Fenbendazole is one of the benzimidazole drugs and is used as a safe anthelmintic drug to treat various parasites. Anti-parasitic effects of fenbendazole result from differences in the structure of tubulin in parasites and mammalian cells, and higher affinity of fenbendazole to tubulin in parasites. Meanwhile, the anti-cancer effects of fenbendazole in mammalian cells were recently reported. Fenbendazole disrupts tubulin and mitotic spindle formation in rapidly dividing tumor cells which results in apoptosis. This study aims to evaluate in vitro anti-cancer effect of fenbendazole in five canine oral melanoma cell lines.

Methods

Five canine melanoma cell lines originated from oral cavity were used. Cell viability was evaluated by MTS assay at 48 hours of fenbendazole treatment. Cell cycle was analyzed by flow cytometry with propidium iodide/RNase solution during 24 hours of treatment. Western blot analysis was used to find an apoptotic effect with cleaved Poly ADP ribose polymerase (PARP).

Results

All melanoma cell lines exhibited reduced cell viability in a dose-dependent manner. A significant decrease in the number of cancer cells was detected at 1 µM fenbendazole treatment and viability decreased below 20% at 100 µM treatment. Cell cycle analysis of all cell lines showed G2/M arrest and increased sub-G1 population. Western blot analysis exhibited that apoptosis was evident from cleaved PARP.

Conclusion

Fenbendazole treatment induces cell cycle arrest in the G2/M phase and decreases cell viability via apoptosis.

Funding Information

This research was carried out with the support of “Cooperative Research Program of Center for Companion Animal Research (Project No. PJ014045022020): Rural Development Administration, Republic of Korea.