Ornidazole suppresses CD133+ melanoma stem cells via inhibiting hedgehog signaling pathway and inducing multiple death pathways in a mouse model.

Aim: To evaluate the inhibitory effects of ornidazole on the proliferation and migration of metastatic melanoma cell line (B16F10) in vitro and its anti-cancer effects in vivo using a melanoma mouse model.

Methods: We investigated the effects of ornidazole on cell viability (Crystal Violet and MTT assay) and migration ability (wound-healing assay) of B16F10 melanoma cells, and its ability to trigger DNA damage (Comet assay) in vitro. We also sorted CD133+ and CD133- cells from B16F10 melanoma cell line and injected them subcutaneously into Swiss albino mice to induce tumor formation. Tumor-bearing mice were divided into control and treatment groups. Treatment group received intraperitoneal ornidazole injections. Tumors were resected. Real-time polymerase chain reaction was used to determine the expression of genes involved into Sonic hedgehog (Shh) signaling pathway, stemness, apoptosis, endoplasmic reticulum (ER) stress, ER stress-mediated apoptosis, and autophagy. Shh signaling pathway-related proteins and CD133 protein were analyzed by ELISA.

Results: Ornidazole effectively induced DNA damage in CD133+ melanoma cells and reduced their viability and migration ability in vitro. Moreover, it significantly suppressed tumor growth in melanoma mouse model seemingly by inhibiting the Shh signaling pathway and ER-stress mediated autophagy, as well as by activating multiple apoptosis pathways.

Conclusions: Our preclinical findings suggest the therapeutic potential of ornidazole in the treatment of metastatic melanoma. However, larger and more comprehensive studies are required to validate our results and to further explore the safety and clinical effectiveness of ornidazole.