基于氧化应激-线粒体损伤研究声光动力治疗乳腺癌的作用机制

Sono-Photodynamic therapy (SPDT) is a promising method that uses ultrasound and light to activate sensitizers to treat tumors, which enjoys an added advantage than sonodynamic therapy (SDT) or photodynamic therapy (PDT). Our previous researches have confirmed that SDT/PDT notably induces apoptosis in tumor cells accompanied by mitophagy occurrence, and reactive oxygen species (ROS) plays a critically important role in this process. In this project, chlorin e6 will be used as sensitizer to explore the regulatory effect of ROS and mitophagy in cell death induced by SPDT on human breast cancer cells and their corresponding tumor-bearing nude mice. We have found that ROS plays an important role in apoptosis and autophagy, indicating the complicated relationship between apoptosis and autophagy. In this project, chlorin e6 was used as photo/sonosensitizer to explore the regulatory effect of ROS in mitophagy on various breast cancer cells and their corresponding tumor-bearing mice. At first, appropriate parameters of SPDT that induce cell apoptosis and autophagy will be confirmed, then the mechanism of apoptosis and mitophagy will be further analyzed. We will further clarify the role of ROS, p38MAPK and JNK/SAPK signal pathway in the mitophagy and cell apoptosis process using pharmaceutics inhibition and siRNA technology in SPDT treatment. Tumor tissue growth inhibition, angiogenesis, tumor invasion and metastasis will be investigated by Western blot、RT-PCR and other related techniques. Taken together, the studies on the cellular and molecular mechanisms involved in SPDT treatment will finally lay a theoretical and experimental foundation for the clinical use of such a promising therapy.

声光联合疗法（SPDT）是利用超声、激光和光敏剂的协同作用杀伤肿瘤细胞的肿瘤综合治疗模式创新探讨，其抗癌效应显著高于声动力（SDT）或光动力（PDT）疗效。前期研究发现活性氧是SDT/PDT诱导肿瘤细胞凋亡的重要诱因且伴随有线粒体自噬特征，提示凋亡和自噬与抗癌机制相关。项目拟选用光敏剂二氢卟吩e6，通过筛选优化对正常细胞安全而能诱导乳腺癌细胞产生明显自噬和凋亡的SPDT参数组合；探寻SPDT引发乳腺癌细胞自噬和凋亡的路径及规律；采用特异性抑制剂和siRNA技术阐明活性氧、线粒体自噬、细胞凋亡的交互作用关系及相关细胞信号通路调控；建立乳腺癌荷瘤裸鼠模型，通过小动物活体成像、Western Blot、RT-PCR等研究SPDT对荷瘤裸鼠肿瘤组织的生长抑制、血管生成、浸润转移等方面的影响，综合分析氧化应激、自噬和凋亡在SPDT在体抗癌研究中的不同效应及机制，为SPDT应用于临床治疗提供科学依据。

癌症是全世界严重威胁人类健康的主要疾病之一，目前针对肿瘤的治疗尚无有效策略，因此探索肿瘤的靶向性治疗技术和新方法是当前生物医学的研究热点和亟待解决的重大问题。声光联合疗法（SPDT）是利用超声、激光和光敏剂的协同作用杀伤肿瘤细胞的肿瘤综合治疗模式创新探讨，其抗癌效应显著高于声动力（SDT）或光动力（PDT）疗效。前期研究发现活性氧是SDT/PDT诱导肿瘤细胞凋亡的重要诱因且伴随有线粒体自噬特征，提示凋亡和自噬与抗癌机制相关。项目选用光敏剂二氢卟吩e6，通过筛选优化对正常细胞安全而能诱导乳腺癌细胞产生明显自噬和凋亡的SPDT参数组合；探寻了SPDT引发乳腺癌细胞自噬和凋亡的路径及规律；采用抑制剂研究了活性氧、线粒体自噬、细胞凋亡的交互作用关系及相关的细胞信号通路调控；通过小动物活体成像、Western Blot、RT-PCR等研究了SPDT对荷瘤小鼠肿瘤组织的抑制作用、血管生成、浸润转移等方面的影响，综合分析了氧化应激、自噬和凋亡在SPDT在体抗癌研究中的不同效应及机制，为SPDT应用于临床治疗提供了实验数据。