Hung Wen-Yi, Huang Kuo-Hung, Wu Chew-Wun, Chi Chin-Wen, Kao Hwa-Li, Li Anna Fen-Yau, Yin Pen-Hui, Lee Hsin-Chen
Department and Institute of Pharmacology, School of Medicine, National Yang-Ming University, and Department of Surgery, Taipei Veterans General Hospital, Taipei, Taiwan.
Biochim Biophys Acta. 2012 Jul;1820(7):1102-10. doi: 10.1016/j.bbagen.2012.04.016. Epub 2012 Apr 26.
Mitochondrial dysfunction has been shown to promote cancer cell migration. However, molecular mechanism by which mitochondrial dysfunction enhances gastric cancer (GC) cell migration remains unclear.
Mitochondria specific inhibitors, oligomycin and antimycin A, were used to induce mitochondrial dysfunction and to enhance cell migration of human gastric cancer SC-M1 cells. Antioxidant N-acetylcysteine (NAC) was used for evaluating the effect of reactive oxygen species (ROS). Protein expressions of epithelial-to-mesenchymal transition (EMT) markers and the cell-extracellular matrix (ECM) adhesion molecules, the integrin family, were analyzed. A migratory subpopulation of SC-M1 cells (SC-M1-3rd) was selected using a transwell assay for examining the association of mitochondrial bioenergetic function, intracellular ROS content and β5-integrin expression. Clinicopathologic characteristics of β5-integrin expression were analyzed in GC specimens by immunohistochemical staining.
Treatments with mitochondrial inhibitors elevated mitochondria-generated ROS and cell migration of SC-M1 cells. The protein expression of β5-integrin and cell surface expression of αvβ5-integrin were upregulated, and which were suppressed by NAC. Pretreatments with NAC and anti-αvβ5-integrin neutralizing antibody respectively prevented the mitochondrial dysfunction-induced cell migration. The selected migratory SC-M1-3rd cells showed impaired mitochondrial function, higher mitochondria-generated ROS, and increased β5-integrin expression. The migration ability was also repressed by anti-αvβ5-integrin neutralizing antibody. In clinical specimens, GCs with higher β5-integrin protein expression had more aggressive behavior. In conclusion, mitochondrial dysfunction may lead to GC progression by enhancing migration through mitochondria-generated ROS mediated β5-integrin expression.
These results support the role of mitochondrial dysfunction in GC progression.
线粒体功能障碍已被证明可促进癌细胞迁移。然而，线粒体功能障碍增强胃癌（GC）细胞迁移的分子机制仍不清楚。
使用线粒体特异性抑制剂寡霉素和抗霉素A诱导线粒体功能障碍并增强人胃癌SC-M1细胞的迁移。使用抗氧化剂N-乙酰半胱氨酸（NAC）评估活性氧（ROS）的作用。分析上皮-间质转化（EMT）标志物和细胞-细胞外基质（ECM）粘附分子整合素家族的蛋白表达。使用Transwell试验选择SC-M1细胞的迁移亚群（SC-M1-3rd），以检查线粒体生物能量功能、细胞内ROS含量和β5整合素表达之间的关联。通过免疫组织化学染色分析GC标本中β5整合素表达的临床病理特征。
线粒体抑制剂处理可提高线粒体产生的ROS水平并促进SC-M1细胞迁移。β5整合素的蛋白表达和αvβ5整合素的细胞表面表达上调，而NAC可抑制这种上调。NAC和抗αvβ5整合素中和抗体预处理分别可阻止线粒体功能障碍诱导的细胞迁移。所选的迁移性SC-M1-3rd细胞显示线粒体功能受损、线粒体产生的ROS水平升高以及β5整合素表达增加。抗αvβ5整合素中和抗体也可抑制其迁移能力。在临床标本中，β5整合素蛋白表达较高的GC具有更强的侵袭性。总之，线粒体功能障碍可能通过线粒体产生的ROS介导的β5整合素表达增强迁移，从而导致GC进展。
这些结果支持线粒体功能障碍在GC进展中的作用。
