中性粒细胞胞外诱捕网(NETs)在肿瘤的发生中扮演重要角色，但诱导NETs形成的分子机制及其如何参与肝癌发病尚不清楚。申请人前期研究发现：缺氧激活肝癌细胞HMGB1-TLR9-MAPK信号通路，通过调节肿瘤代谢重编程和促进增殖参与肝癌发病；同时促进HMGB1释放、NETs形成和募集肿瘤相关免疫细胞浸润，且NETs能增强肝癌细胞恶性生物学表型。由此我们推测：缺氧诱导肝癌细胞释放的HMGB1通过促进NETs形成，进而调控促癌免疫微环境形成。本项目拟采用靶向功能缺失/获得策略，在分子、细胞和动物水平研究缺氧诱导肝癌细胞释放的HMGB1通过调控中性粒细胞胞内TLR9-MAPK信号通路促进NETs形成并刺激肝癌细胞分泌促癌细胞/趋化因子，募集更多免疫抑制细胞浸润，诱导肿瘤免疫耐受参与肝癌发病。从肿瘤细胞和免疫细胞相互作用角度阐明HMGB1调控肝癌发病的新机制，并为寻找肿瘤治疗新靶点奠定理论基础。

Neutrophil extracellular traps (NETs), which composed of DNA strands and neutrophil granule proteins, can participate in the pathogenesis of tumor and tumor-related diseases. Until now, reports on the molecular mechanism of NETs formation and the role of NETs in the progression of hepatocarcinogenesis are scarce. Our previous research had revealed that during hypoxia， HMGB1-TLR9-MAPK signal pathway was activated in hepatocellular carcinoma (HCC)，which participates in the pathogenesis of HCC by regulating tumor metabolic reprogramming and promoting proliferation. Hypoxic microenvironment also increased HMGB1 release, NETs formation and tumor-associated immune cell infiltration in HCC. In vitro experiment indicated that NETs enhanced the malignant biological behaviors of HCC cell lines. Based on these, we hypothesized that hypoxia induced HMGB1 release from HCC cells promoting NETs formation, consequently, facilitating protumorigenic inflammatory microenvironment establishment to involve in hepatocarcinogenesis. We will apply targeted gain of function and loss of function strategy to illustrate whether hypoxia induced release of HMGB1 from HCC cells promotes NETs formation by regulating TLR9-MAPK signaling pathway of neutrophils, and NETs formation plays a key role in hepatocellular carcinogenesis through excretes pro-tumor inflammatory cytokines and chemokines, recruits more immunosuppressive cells, such as tumor-associated macrophages (TAM) and T-regulatory (Treg) cells, to induce immune tolerance in vitro and in vivo. In conclusion, our study will provide a brand-new molecular mechanism to illustrate how HMGB1 regulates hepatocellular carcinoma progression，it will also be developed as potential new target for the therapy of HCC.