FSCN1抑制自噬并通过HK2激活糖酵解促进喉鳞癌侵袭转移的分子机制研究

Invasion and metastasis are major risk factors for poor prognosis of laryngeal squamous cell carcinoma (LSCC). Impaired autophagy and high levels of glycolysis are closely related with invasion and metastasis. LSCC has the special microenvironment of impaired autophagy and elevated glycolysis, but the regulatory mechanism remains unclear. Previous studies have shown that autophagy modulates the level of glycolysis through degradation of HK2 specifically, and PIK3C2B inhibits autophagy through activation of AKT phosphorylation. Our previous work found that FSCN1 is abnormally upregulated in LSCC. The high expression of FSCN1 was positively correlated with advanced T staging and cervical lymph node metastasis, and considered as an independent indicator of poor prognosis of LSCC. Moreover, our results revealed that FSCN1 regulates protein level of PIK3C2B and HK2 via binding to their directly. Knockdown of FSCN1 not only activates autophagy, but also decreases the level of glycolysis and inhibits the migration and invasion of LSCC cells. In this project, CRISPR/Cas9, Co-IP and site directed mutagenesis will be introduced to unravel the mechanism of FSCN1 regulates the autophagy and glycolysis of LSCC by modulation of PIK3C2B/AKT pathway and HK2 stability, and then the clinical significance will be analyzed by xenograft model and clinical data. The results of this project will further expands our knowledge on the invasion and metastasis of LSCC from a new perspective of “autophagy-glycolysis regulation”, and provides new ideas for molecular targeted therapy for LSCC.

易侵袭转移是喉鳞癌预后不良的主要风险因素。自噬受阻及高水平糖酵解与肿瘤侵袭转移关系密切，而喉鳞癌中存在此特殊微环境，但具体调控机制不清。文献报道自噬可通过降解HK2调节糖酵解水平，而PIK3C2B通过AKT磷酸化使肿瘤细胞自噬受阻。本课题组前期研究表明FSCN1在喉鳞癌中异常上调，与患者T分期及颈淋巴结转移呈正相关，且是独立预后不良影响因子。进一步研究发现FSCN1能与PIK3C2B及HK2直接结合并影响两者蛋白水平，敲降FSCN1不仅可激活喉鳞癌细胞自噬，还能显著降低糖酵解水平，迁移侵袭能力亦受到遏制。本项目首先拟利用CRISPR/Cas9、Co-IP、定点突变等体外实验，明确FSCN1经PIK3C2B/AKT及HK2介导调控喉鳞癌自噬与糖酵解的重要机制，其次通过移植瘤及临床标本检测总结临床意义。从“自噬-糖酵解调控”的新视角进一步丰富喉鳞癌侵袭转移的分子理论，为该病靶向治疗提供新思路。

易侵袭转移是喉鳞癌预后不良的主要风险因素。自噬受阻及高水平糖酵解与肿瘤侵袭转移关系密切，而喉鳞癌中存在此特殊微环境，但具体调控机制不清。我们前期研究发现，敲降FSCN1不仅可激活喉鳞癌细胞自噬，还能显著降低糖酵解水平，迁移侵袭能力亦受到遏制。本项目在此基础上进一步研究发现FSCN1通过AKT信号通路调控喉鳞癌细胞自噬。FSCN1与HK2直接互作并影响其稳定性，进而调控喉鳞癌细胞糖酵解。而抑制FSCN1诱导自噬可激活喉鳞癌细胞糖酵解，促进细胞迁移侵袭。本项目初步明确了FSCN1经AKT通路及HK2介导调控喉鳞癌自噬与糖酵解的重要机制。从“自噬-糖酵解调控”的新视角进一步丰富喉鳞癌侵袭转移的分子理论，为该病靶向治疗提供新思路。