乳腺癌是全世界女性最高发的恶性肿瘤，其发病趋于年轻化且预后较差。TENT5A被报道与乳腺癌患者对5-氟尿嘧啶的化疗敏感性密切相关。TENT5A蛋白属于一类新型的聚腺苷化聚合酶家族蛋白，但长期以来其具体的生物学功能一直未知。为了明确TENT5A蛋白催化的具体的生化反应及其发挥的细胞学功能，我们拟从解析TENT5A蛋白的晶体结构入手，系统研究揭示其催化的生化反应及其效应，在此基础上探索TENT5A与乳腺癌细胞化疗敏感性的具体的相关性，并在分子水平上揭示其内在的机制，并通过寻找相互作用蛋白揭示TENT5A可能参与的细胞内信号通路及其他生物学过程，为之后设计小分子靶向药改善乳腺癌患者的化疗疗效提供科学基础，以期改善患者的预后，最终提高其生存率。

Breast cancer is the most common malignancy among women worldwide, and its incidence tends to be younger and its prognosis is poor. TENT5A was reported to be closely associated with breast cancer patients’ response to 5-fluorouracil. TENT5A protein belongs to a new class of poly (A) polymerase superfamily, but its biological function remains ambiguous. In order to define the catalytic mechanism and cellular role of TENT5A protein, we will start our work with solving the crystal structure of TENT5A protein, then exploring its biochemical activities systematically. We will study on the correlation between TENT5A and drug response in breast cancer cells and try to reveal its molecular mechanism. In addition, we sought to search for the interacting proteins to further speculate the signaling pathway and biological processes TENT5A may take part in. The results will help researchers to design small biological molecules to enhance the drug response of breast cancer patients, which eventually, improve the patient's prognosis and their survival rate.