Department of Chemistry, Faculty of Science , Ferdowsi University of Mashhad , Mashhad , Iran.
Department of Research Cell and Molecular Biology, Institute of Biotechnology , Ferdowsi University of Mashhad , Mashhad , Iran.
Chem Res Toxicol. 2019 Apr 15;32(4):645-658. doi: 10.1021/acs.chemrestox.8b00335. Epub 2019 Mar 14.
BRAF inhibitors (BRAFi) have been applied to treat melanoma harboring V600E mutations. Several studies showed that BRAFi-resistant melanomas are dependent on mitochondrial biogenesis. Therefore, the present study aimed to investigate the influence of ciprofloxacin (CIP), a mitochondria-targeting antibiotic, on SB-590885-resistant BRAF A375 melanoma (A375/SB) cells. The cytotoxicity activity of CIP and SB-590885, a potent and specific BRAFi, on A375 and A375/SB cells was evaluated by MTT, colony formation, migration, and spheroid formation assays. Moreover, SB-590885-induced cell death in A375 cells was analyzed. SB-590885 showed time- and concentration-dependent cytotoxic effects on A375 cells. Twenty-five μg/mL CIP decreased the cell viability of A375 and A375/SB cells in a time-dependent manner. This concentration of CIP markedly decreased clonogenicity in both cells and caused a reduction in the growth of A375/SB spheroids. The cytotoxicity of 5 μg/mL CIP on A375/SB cells was less than that of A375 cells. The colony formation and migration ability of A375/SB cells was increased in the presence of 5 μg/mL CIP. Ten μM SB-590885 induced a massive vacuolization in A375 cells. Cell death assays suggested a simultaneous activation of autophagy, paraptosis, apoptosis, and necrosis. For the first time, this study reveals that CIP at the maximum concentration in serum (5 μg/mL) can enhance the colony formation and migration abilities in BRAFi-resistant melanoma cells, while it has cytotoxic activity against these cells at a higher concentration than serum level. This study suggests that CIP may promote aggressive growth properties in BRAFi-resistant melanomas, at a concentration present in serum.
BRAF 抑制剂（BRAFi）已被用于治疗携带 V600E 突变的黑色素瘤。多项研究表明，BRAFi 耐药的黑色素瘤依赖于线粒体生物发生。因此，本研究旨在探讨靶向线粒体的抗生素环丙沙星（CIP）对 SB-590885 耐药 BRAF A375 黑色素瘤（A375/SB）细胞的影响。通过 MTT、集落形成、迁移和球体形成测定评估 CIP 和 SB-590885（一种强效且特异的 BRAFi）对 A375 和 A375/SB 细胞的细胞毒性活性。此外，分析了 SB-590885 诱导 A375 细胞死亡的情况。SB-590885 对 A375 细胞表现出时间和浓度依赖性的细胞毒性作用。25μg/mL 的 CIP 以时间依赖性方式降低 A375 和 A375/SB 细胞的细胞活力。该浓度的 CIP 显著降低了两种细胞的集落形成能力，并导致 A375/SB 球体的生长减少。5μg/mL 的 CIP 对 A375/SB 细胞的细胞毒性小于 A375 细胞。5μg/mL 的 CIP 存在时，A375/SB 细胞的集落形成和迁移能力增加。10μM SB-590885 在 A375 细胞中诱导大量空泡化。细胞死亡测定表明自噬、副凋亡、凋亡和坏死同时被激活。本研究首次揭示，CIP 在血清中的最大浓度（5μg/mL）可以增强 BRAFi 耐药黑色素瘤细胞的集落形成和迁移能力，而在高于血清水平的浓度下对这些细胞具有细胞毒性活性。本研究表明，CIP 可能会在血清中存在的浓度下促进 BRAFi 耐药黑色素瘤的侵袭性生长特性。
