Electron microscopy of MMAN cells treated with clioquinol and zinc. (A) Control melanoma cells (×5800). The inset demonstrates microvilli present in the control melanoma cells (×12,000). (B) Melanoma cells following treatment with 150 µM zinc chloride (×6000). (C) Melanoma cells following treatment with 7.5 µg/ml clioquinol. The asterisks in the central photograph (×5300) indicate dilated endoplasmic reticulum. The arrows in the upper inset (×15,000) demonstrate focal adhesion plaques, and the lower inset (×14,300) shows increased melanosomes seen as a result of clioquinol treatment. (D) Melanoma cells following treatment with 7.5 µg/ml clioquinol in combination with 150 µM zinc chloride (×7200). The inset (×15,600) demonstrates damaged mitochondria; L, lipid droplets seen in necrotic cells.