近年来越来越多的证据显示线粒体与肿瘤的生长和转移密切相关。本课题预实验通过蛋白质组学的方法已经发现线粒体蛋白COX5B在高转移性的乳腺癌细胞中表达显著下降，在低转移性的乳腺癌细胞中将COX5B抑制后能显著促进乳腺癌的迁移和侵袭能力，提示COX5B可以抑制乳腺癌转移。本课题拟在前期工作基础上，采用细胞、动物及临床标本等实验进一步明确COX5B在乳腺肿瘤转移中的作用，采用基因芯片、蛋白质芯片等技术揭示COX5B抑制乳腺癌转移的具体信号通路及其调控机制；确定COX5B在乳腺癌诊治中的临床意义，探索其与乳腺癌类型、淋巴结转移、病人生存率等指标之间的临床规律。本课题将侧重研究COX5B抑制乳腺癌转移的作用与机制，有助于全面揭示COX5B抑制乳腺癌转移的分子机制，有助于发现乳腺癌转移过程中新的分子靶点，对于指导临床治疗乳腺癌具有实际的应用价值。

Mitochondrial dysfunction can change tumor microenvironment and promote tumor growth and metastasis. Mitochondrial respiratory chain is required for tumor initiation, growth, apoptosis and metastasis，but few of them focus on the function of complex Ⅳ for tumor growth and metastasis. Our pre-experiments demonstrated that cox5B，one subunit of compex Ⅳ，showed lower expression in highly metastatic breast cancer cells than primary cancer cells by Proteomics. Besides, inhibition of COX5B significantly promoted breast cancer migration and invasion, suggesting that COX5B can suppress breast cancer metastasis. In this study, we will further clarify the role of COX5B in breast cancer metastasis by adopting gene microarray, protein microarray and other methods to reveal the underline mechanism. Furthermore, we will confirm how COX5B clinically relates to breast cancer metastasis, survival rate and prognosis. This research is helpful to explore the relevance between mitochondria and breast cancer metastasis and cast light on a potential new target molecule which may be a potent diagnostic marker for breast cancer.