Increased reactive oxygen species (ROS) production by arsenic treatment in solid tumors showed to be effective to sensitize cancer cells to chemotherapies. Arsenic nano compounds are known to increase the ROS production in solid tumors. In this study we developed arsenic–ferrosoferric oxide conjugated Nano Complex (As2S2–Fe3O4, AFCNC) to further promote the ROS induction ability of arsenic reagent in solid tumors. We screen for the molecular pathways that are affect by arsenic treatment in ESCC cancer cells. And explored the underlying molecular mechanism for the arsenic mediated degradations of the key transcription factor we identified in the gene microarray screen. Mouse xenograft model were used to further verify the synthetic effects of AFCNC with chemo and radiation therapies, and the molecular target of arsenic treatment is verified with IHC analysis. With gene expression microarray analysis we found Hippo signaling pathway is specifically affected by arsenic treatment, and induced ubiquitination mediated degradation of YAP in KYSE-450 esophageal squamous cell carcinoma (ESCC) cells. Mechanistically we proved PML physically interacted with YAP, and arsenic induced degradation PML mediated the degradation of YAP in ESCC cells. As a cancer stem cell related transcription factor, YAP 5SA over expressions in cancer cells are correlated with resistance to chemo and radiation therapies. We found AFCNC treatment inhibited the increased invasion and migration ability of YAP 5SA overexpressing KYSE-450 cells. AFCNC treatment also effectively reversed protective effects of YAP 5SA overexpression against cisplatin induced apoptosis in KYSE-450 cells. Lastly, with ESCC mouse xenograft model we found AFCNC combined with cisplatin treatment or radiation therapy significantly reduced the tumor volumes in vivo in the xenograft ESCC tumors. Together, these findings suggested besides ROS, YAP is a potential target for arsenic based therapy in ESCC, which should play an important role in the synthetic effects of arsenic nano complex with chemo and radiation therapy.

中文翻译：

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砷纳米复合物诱导YAP致敏ESCC癌细胞降解以进行放射和化学疗法

在实体瘤中通过砷处理增加了活性氧（ROS）的产生，可以有效地使癌细胞对化学疗法敏感。已知砷纳米化合物会增加实体瘤中的ROS产生。在这项研究中，我们开发了砷-二氧化三铁共轭纳米复合物（As2S2-Fe3O4，AFCNC），以进一步增强砷剂在实体瘤中的ROS诱导能力。我们筛选了受砷处理的ESCC癌细胞中影响的分子途径。并探索了我们在基因芯片筛选中鉴定的关键转录因子的砷介导降解的潜在分子机制。小鼠异种移植模型用于进一步验证AFCNC与化学疗法和放射疗法的合成作用，并通过IHC分析验证了砷治疗的分子靶标。通过基因表达微阵列分析，我们发现了Hippo信号通路受到砷处理的特异性影响，并在KYSE-450食道鳞状细胞癌（ESCC）细胞中诱导了泛素介导的YAP降解。从机理上讲，我们证明了PML与YAP发生了物理相互作用，并且砷诱导的PML介导了ESCC细胞中YAP的降解。作为与癌症干细胞相关的转录因子，YAP 5SA在癌细胞中的过度表达与对化学疗法和放射疗法的抗性相关。我们发现AFCNC处理抑制了过表达KYSE-450细胞的YAP 5SA的增加的侵袭和迁移能力。AFCNC处理还有效逆转了YAP 5SA过表达对顺铂诱导的KYSE-450细胞凋亡的保护作用。最后，在ESCC小鼠异种移植模型中，我们发现AFCNC与顺铂治疗或放射治疗相结合可显着减少异种移植ESCC肿瘤的体内肿瘤体积。总之，这些发现提示，除了ROS外，YAP也是ESCC中基于砷的治疗的潜在目标，YAP在化学与放射治疗的砷纳米复合物的合成作用中应发挥重要作用。