Melanoma is the most common type of skin cancer. Melanomas are well known for their ability to metastasize to other organs, including the lungs, liver, brain, and bones. The ability of melanoma cells to switch among different phenotypes is a key mechanism that underscores their metastatic potential. The objective of this work is to report here on the effect of calcium sulfide (CaS) dispersions in melanoma cells. Melanomas with the epithelial- and mesenchymal-like phenotypes were observed during cell culture preparation. The dose-dependent viability was explored up to slightly less than 3% per volume of cell culture. The dispersion reduced the relative percentage of melanomas with the epithelial- and mesenchymal-like phenotypes to (57 ± 5) and (55 ± 5)%, respectively, at 24 h post treatment. In contrast, the viability of normal fibroblasts treated with the dispersion or melanoma cells treated with the reactants used to prepare the dispersion remained nearly constant, with a value range of (100.0 ± 0.2)% for the control and (97 ± 4)% and (93 ± 2)% for doses as high as 2 and 3% per volume of cell culture, respectively. Fluorescence imaging measurements were consistent with the release of cytochrome c from the mitochondria and its translocation to the cell nuclei. The average expression of caspases 3 and 9 was found to be 3 and 1.4 times higher than in the corresponding melanoma control, respectively, which was consistent with intrinsic apoptosis. The response of vinculin expression was slightly different in both cell phenotypes. Vinculin was found to delocalize in the cytoplasm of treated mesenchymal melanoma cells, with a slightly higher concentration at the end of the actin fibers. A statistically significant increase (p< 0.0001) in the number of focal adhesion points (FAP) at the edge of the cell membrane–external cellular matrix (ECM) interphase was observed in post-treated melanoma that exhibited the epithelial-like phenotype. The changes in vinculin expression and FAP and the reduced viability of the melanomas were consistent with regulation of proteins associated with programmed cell death. It is thus proposed that the sulfides produced from the reactions of the nanoclusters in the acidic environment facilitate the regulation of proteins required to initiate apoptosis, although other processes may also be involved. We conclude that CaS may be an adequate chemical to selectively reduce melanoma viability with little effect on benign fibroblasts.
黑色素瘤是最常见的皮肤癌类型。该肿瘤以向肺、肝、脑及骨骼等多器官转移的特性而广为人知。黑色素瘤细胞在不同表型间转换的能力是其转移潜能的關鍵机制。本研究旨在探讨硫化钙（CaS）分散体系对黑色素瘤细胞的影响。细胞培养过程中观察到上皮样与间质样表型的黑色素瘤细胞。剂量依赖性实验显示，当培养体系添加浓度略低于3%（体积比）时，细胞活性呈现梯度变化。处理24小时后，分散体系使上皮样与间质样表型黑色素瘤细胞的相对百分比分别降至（57±5）%和（55±5）%。相比之下，经分散体系处理的正常成纤维细胞及使用分散体系制备反应物处理的黑色素瘤细胞活性保持稳定：对照组为（100.0±0.2）%，而添加浓度高达2%和3%（体积比）的实验组分别为（97±4）%和（93±2）%。荧光成像检测显示线粒体释放细胞色素c并向细胞核转位。Caspase-3和caspase-9的平均表达量分别是对照组的3倍和1.4倍，符合内源性凋亡特征。两种细胞表型中纽蛋白表达响应略有差异：在处理后的间质样黑色素瘤细胞中，纽蛋白在细胞质内发生去定位，并在肌动蛋白纤维末端呈现轻微聚集。在上皮样表型的处理后黑色素瘤细胞中，细胞膜-细胞外基质界面处的黏着斑数量出现统计学显著增加（p<0.0001）。纽蛋白表达与黏着斑的变化及黑色素瘤活性降低，均与程序性细胞死亡相关蛋白的调控机制相符。由此推测，纳米团簇在酸性环境中反应生成的硫化物可能通过调控凋亡启动相关蛋白发挥作用，尽管其他过程也可能参与其中。本研究结论表明，CaS或可作为选择性降低黑色素瘤活性且对良性成纤维细胞影响甚微的适宜化学制剂。
Engineered Nanoclusters to Selectively Reduce Mesenchymal and Epithelial Melanoma Cell Viability
肿瘤(癌症)患者之家