Mitochondria-targeted magnolol inhibits OXPHOS, proliferation, and tumor growth via modulation of energetics and autophagy in melanoma cells

INTRODUCTION: Melanoma is an aggressive form of skin cancer for which there are no effective drugs for prolonged treatment. The existing kinase inhibitor antiglycolytic drugs (B-Raf serine/threonine kinase or BRAF inhibitors) are effective for a short time followed by a rapid onset of drug resistance. PRESENTATION OF CASE: Here, we show that a mitochondria-targeted analog of magnolol, Mito-magnolol (Mito-MGN), inhibits oxidative phosphorylation (OXPHOS) and proliferation of melanoma cells more potently than untargeted magnolol. Mito-MGN also inhibited tumor growth in murine melanoma xenografts. Mito-MGN decreased mitochondrial membrane potential and modulated energetic and mitophagy signaling proteins. DISCUSSION: Results indicate that Mito-MGN is significantly more potent than the FDA-approved OXPHOS inhibitor in inhibiting proliferation of melanoma cells. CONCLUSION: These findings have implications in the treatment of melanomas with enhanced OXPHOS status due to metabolic reprogramming or drug resistance.