氧化应激介导的HMGB1核移位在恶性黑素瘤转移中的作用研究

Tumor metastasis is the crucial cause of recurrence and death for malignant melanomas. Reactive oxygen species（ROS）induced oxidative stress can be involved in melanoma metastasis. An elevated redox homeostasis of melanoma cells is formed for undergoing higher ROS level. In our primitive study, we have found the HMGB1 expression level of melanoma is correlated with metastasis, however, the mechanism of which is still unclear. More intriguingly, we have observed HMGB1 highly expressed in cytoplasm of metastasis melanoma tissue, while in the H2O2 treated oxidative melanoma cell model, an increased nucleocytoplasmic translocation could be detected. All of the data sugget the nucleocytoplasmic translocation of HMGB1 mediated by oxidative stress could influence melanoma metastasis. Here, we would detect the oxidative status and metastasis ability in different H2O2 treated melanoma cells and HMGB1 expression /subcellular distribution melanoma cells. Subsequently, we would use biological and molecular methods to investigate the possible mechanism. Lastly, we would identify the cell model results by using animal models and clinical samples. Based on the above, we would like to elucidate the role of oxidative stress with HMGB1 in regulation of melanoma metastasis, with the aim to provide new clues for the treatment of melanoma.

恶性黑素瘤转移是导致患者肿瘤复发和致死的主要原因。研究表明，ROS所致氧化应激与黑素瘤转移调控有关。黑素瘤细胞中ROS水平增高，其通过建立新氧化应激平衡体系维持细胞恶性生物学行为。前期工作表明，HMGB1与黑素瘤转移调控有关，然具体机制尚未明确。通过进一步地临床观察发现，发生转移的黑素瘤患者组织标本中HMGB1在胞浆表达增高；同时，H2O2处理的黑素瘤细胞氧化应激模型中HMGB1出现核浆移位。由此提出，氧化应激介导的HMGB1核移位可能影响着恶性黑素瘤的转移。本项目将预先明确不同H2O2处理或不同HMGB1表达/定位对黑素瘤细胞氧化-抗氧化及转移能力的影响，接着通过双向凝胶电泳和基因检测等技术初步探讨氧化应激介导HMGB1核移位在黑素瘤细胞转移调控中的机制，最后利用动物实验及临床标本验证细胞学实验的结果，旨在以此切入点，为寻求新临床治疗手段提供理论参考。

恶性黑素瘤转移是导致患者肿瘤复发和致死的主要原因。研究表明，ROS所致氧化应激与黑素瘤转移调控有关。黑素瘤细胞中ROS水平增高，其通过建立新氧化应激平衡体系维持细胞恶性生物学行为。前期工作手提示HMGB1与黑素瘤转移调控有关，且具体机制尚未明确。根据研究计划，我们检测了不同黑色素瘤细胞株迁移侵袭能力及氧化应激水平，发现各细胞株中ROS的产生与其迁移侵袭能力成正相关且伴随HMGB1蛋白高表达；通过构建HMGB1核浆定位突变体，进一步发现黑素瘤细胞中HMGB1蛋白胞浆细胞定位有利于其侵袭转移等恶性生物学行为发生；初步探讨发现MAPKs信号通路可能参与HMGB1亚细胞定位介导的氧化应激调控过程。通过免疫组化方法检测黑素瘤组织中HMGB1蛋白表达情况，发现其胞浆高表达水平与肿瘤远处转移及分期相关，且提示患者预后不良。本研究探讨了氧化应激下HMGB1参与黑素瘤转移调控的可能机制，也为寻求新临床治疗手段提供理论参考。