血浆外泌体lncRNA-IGFBP4-1调控糖酵解在肺腺癌发生、预后中的作用和机制研究

Nowadays, the role of exosome lncRNA in tumorigenesis and development and its potential as a biomarker for early diagnosis and progression evaluation have been the hot research topic. Although, we have previously found that lnc-IGFBP4-1 in lung cancer tissues could promote the occurrence and development of lung cancer by regulating glycolysis, and the expression of lncRNA in plasma exosomes was positively correlated with that in lung adenocarcinoma tissues of lung adenocarcinoma patients, the role and mechanism of lncRNA in lung adenocarcinoma occurrence and prognosis of lung adenocarcinoma in exosomes were unknown. IFG signaling pathway is closely related to glycolysis, and results of cell sequencing showed that exosome lnc-IGFBP4-1 may regulate the expression of related genes in IGF signaling pathway. It suggests that exosomes lnc-IGFBP4-1 may be involved in regulating glycolysis through the IGF signaling pathway, which would promote the occurrence and development of lung adenocarcinoma. In a case-control study, the association between the lncRNA and lung adenocarcinoma risk as well as prognosis will be evaluated by testing lnc-IGFBP4-1 in plasma exosomes; And the molecular mechanism of exosomal lnc-IGFBP4-1 on regulating glycolysis through IGF pathway will be investigated by using gain of function and loss of function with over expressions plasmid transfection and siRNA interference technology in vitro, which will provide a new scientific basis for screening, prevention and treatment, and prognosis evaluation of the high-risk population of lung adenocarcinoma.

外泌体lncRNA在肿瘤发生发展中的作用及其作为早期诊断和进展评价生物标志物的潜力是目前研究的热点。申请人前期研究发现肺癌组织中lnc-IGFBP4-1可通过调控糖酵促进肺癌的发生发展，且该lncRNA在肺腺癌人群血浆外泌体和肺腺癌组织中的表达呈正相关，但外泌体中该lncRNA在肺腺癌发生和预后中的作用及机制不明。IFG信号通路与糖代谢密切相关，细胞测序结果发现外泌体lnc-IGFBP4-1可能调控IGF信号通路相关基因的表达。提示，外泌体lnc-IGFBP4-1可能通过IGF信号通路参与调控糖代谢，促进肺腺癌的发生发展。本课题拟通过病例对照研究，分析血浆外泌体lnc-IGFBP4-1与肺腺癌发病、预后的关联；采用过表达和siRNA干扰技术，结合体内实验揭示该外泌体lncRNA调控IGF信号通路参与糖酵解影响肺腺癌发生发展的分子机制，为肺腺癌高危人群筛查、防治及预后评估提供新的科学依据。

肺癌已成为全世界发病率和死亡率最高的恶性肿瘤，严重威胁人类健康和生命安全，也是全球癌症死亡的首要原因，已成为一个必须高度重视的公共健康问题。肺癌中的主要病理类型-肺腺癌的发生是环境因素联合遗传因素共同作用的结果，其中遗传因素导致了个体发生肿瘤的易感性。因此，探索与环境危险因素相关且能用于肺癌早期诊断和进展评价的生物标志物一直是研究的关键点。结合前期项目，本项目围绕着这个关键点分三部分进行展开：首先，在98对肺腺癌病例对照人群血浆和63对肺腺癌和对应的癌旁组织中检测了外泌体lnc-IGFBP4-1表达水平，发现血浆外泌体lnc-IGFBP4-1分别与人群肺腺癌发病相关联（p<0.01）；血浆外泌体lnc-IGFBP4-1与组织外泌体lnc-IGFBP4-1存在相关关系（r=0.664，p<0.05）；lnc-IGFBP4-1主要分布与细胞核中；其次，在苯并[a]芘和六价铬的诱导下，均能增加lnc-IGFBP4-1表达水平；苯并[a]染毒可引起肺癌细胞系NCI-H292细胞的存活率下降， 且随着染毒剂量增加毒性作用增强；苯并[a]芘可刺激NCI-H292 细胞分泌IL-1β和IL-８，其可能在苯并[a]芘致肺肿瘤炎症过程中发挥重要作用；另外，六价铬暴露均可引起A549和16HBE细胞的细胞毒性，存在时间-剂量效应关系，引起ROS含量增加和GPX4mRNA表达水平发生改变。此外，我们发现288名年轻焦炉工人群中，PAHs暴露与KRAS外显子2和BRAF外显子15的损伤分别呈正相关，且呈非线性剂量响应模式；XPC基因变异(以rs2221008G等位基因和rs3731055GG纯合子基基因型)的个体可能预测PAHs暴露和吸烟引起KRAS第2外显子损伤的易感性，为易感人群的个性化预防和干预措施提供了科学依据，以应对环境暴露造成的有害健康影响；也为进一步了解基因和环境因素对肺癌发生的潜在生物学机制提供了科学线索。项目的实施的现实意义主要体现在基因-环境联合作用的探讨，为后续筛查易感人群提供了支持；其次，为肺癌早期健康效应的监测和评估提供了效应标志物，有环境暴露危险因素的人群提供防护措施。