HMGB3在非小细胞肺癌中促进肿瘤细胞增殖的作用和调控机理研究

Continuous proliferation capability is the basis of tumor biological characteristics; in-depth study of its molecular mechanism is of great significance for the guidance of clinical treatment. HMGB3 (High Mobility Group Box3) is one of high mobility group protein B family member, our previous study found that HMGB3 expression is closely correlated with non small cell lung cancer (non-small cell lung cancer, NSCLC) cell proliferation, and the mechanism is probably by affecting the expression of transcription factor FoxM1 and cell cycle proteins, but the detailed mechanism is still unclear. This study will first use RNAi and overexpression techniques to validate HMGB3 role in promoting NSCLC cell proliferation. Then, ChIP-seq technology will be adopted to analyze HMGB3 regulation sites in the whole genome, and co-immunoprecipitation and TOF-MS techniques will be used to analyze proteins interacted with HMGB3, which will reveal the detailed regulation pathway how HMGB3 interact with FoxM1 to affect cell proliferation. In addition, the regulatory pathway network can be constructed to screen critical regulation molecules. Finally, correlation between critical molecules in the HMGB3 pathway and clinical parameters will be analyzed to provide potential therapeutic targets for prognosis value and clinical treatment of NSCLC.

肿瘤的持续增殖能力是肿瘤生物学特性的基础，深入研究其分子机理，对指导治疗具有重要意义。HMGB3是高迁移率族蛋白B族成员之一，我们前期研究发现该基因表达与非小细胞肺癌增殖相关，并发现HMGB3可以通过调控FoxM1及其下游靶基因促进肿瘤细胞增殖，具体调控机理尚不清楚。本项目拟先采用RNA干扰和过表达技术，分析下调和上调HMGB3表达对肿瘤细胞增殖的影响，明确HMGB3促进肿瘤细胞增殖的作用；采用ChIP-seq技术分析HMGB3的全基因组调控位点，以及运用免疫共沉淀与TOF-MS技术分析与HMGB3协同作用的蛋白，进而探讨HMGB3对FoxM1的调控方式，揭示HMCB3通过调控FoxM1表达进而调控细胞增殖的分子机制，从而构建HMGB3调控非小细胞肺癌细胞增殖的分子网络，筛选出其调控的关键分子；最后在非小细胞肺癌临床标本中验证HMGB3与关键分子的临床意义，为非小细胞肺癌治疗提供重要靶点。

HMGB3为肿瘤细胞增殖的关键分子。我们的实验首先在体外证实了HMGB3具有促进非小细胞肺癌细胞增殖的作用。在临床标本中，HMGB3的过表达与肺腺癌的TNM分期有关，为患者的不良预后因素之一。我们进一步通过分子生物学实验，干扰和过表达实验技术，证实了FOXM1为Hmgb3信号通路中的关键分子。并且HMGB3通过FOXM1进一步影响下游C-myc、CDC25B、CyclinB1等细胞周期分子来调控细胞增殖。我们通过蛋白质谱分析找出，HMGB3相互作用的蛋白LSD1，并在体外用Co-IP实验证实HMGB3通过与LSD1相互作用，调控FOXM1的表达。在此，我们构建了HMGB3促进非小细胞肺癌肿瘤细胞增殖的分子调控网络。另外我们在非小细胞肺癌脑转移标本中观察到HMGB3的高表达，在体外实验中证实HMGB3具有促进肿瘤转移的作用。以上研究为理解NSCLC的发生和发展提供新的思路，为HMGB3在临床上作为抗肿瘤增殖的新靶点提供理论依据。