LINC00958通过调控FSCN1基因启动子组蛋白乙酰化修饰促进非小细胞肺癌进程的机制研究

Non-small-cell lung cancer (NSCLC) has high incidence and mortality rates, and the therapeutic effects are unsatisfactory. In previous study, a significantly increased expression of FSCN1 mRNA in NSCLC was found, which indicated abnormal regulation at the transcription level. The preliminary experiment showed increased levels of histone acetylation in the FSCN1 promoter region and upregulated expression of acetyltransferase HAT1 in the NSCLC cell line A549. Bioinformatics analysis revealed LINC00958, a lincRNA that correlates positively with FSCN1 expression and has high expression in NSCLC. Both LINC00958 and HAT1 mRNA had binding sites with miR-342, and miR-342 was negatively correlated with the expression of LINC00958 and HAT1. Therefore, it was deduced that LINC00958 in NSCLC cells enhances HAT1 expression through miR-342 adsorption and consequently increases histone acetylation in the FSCN1 promoter region, resulting in high FSCN1 expression. Using RIP-Seq, ChIP-PCR, tumor formation in nude mice, and other experiments, this project will examine the intricate regulation mechanisms involved in abnormal FSCN1 expression during NSCLC progression, and offer new avenues to pursue clinical NSCLC treatments.

非小细胞肺癌（NSCLC）发病率及死亡率高，患者预后差。申请者发现FSCN1mRNA在NSCLC中明显升高，这说明其在转录水平调控异常。预实验结果显示在NSCLC细胞A549中FSCN1基因启动子组蛋白乙酰化修饰水平升高，同时乙酰转移酶HAT1的表达也出现上调。利用生物信息学分析，申请者发现一个与FSCN1表达呈正相关且同样在NSCLC中高表达的lncRNA：LINC00958，其和HAT1mRNA均与miR-342存在结合位点，且miR-342与LINC00958、HAT1的表达呈负相关。因此，推测在NSCLC中，LINC00958通过吸附miR-342，促进HAT1表达，进而提高FSCN1启动子乙酰化水平，最终使FSCN1高表达。本项目拟通过RIP-Seq、ChIP-PCR及裸鼠成瘤等实验，探究FSCN1在NSCLC进程中异常表达的精细调控机制，并为临床治疗NSCLC提供新的思路。

肺腺癌（LUAD）是肺癌最常见的组织学亚型。调节多种肿瘤恶性行为的长链非编码 RNA LINC00958在LUAD中的作用尚未阐明。采用组织微阵列、FISH和qRT-PCR检测LINC00958的表达。质粒和病毒感染用于操纵基因表达。通过动物模型的细胞增殖分析、细胞凋亡分析、细胞迁移和侵袭分析、皮下接种等方法研究了LINC00958在LUAD中的作用。同时，进行了RNA-Seq、RNA pull-down、ChIRP、ChIP和荧光素酶报告基因检测以阐明机制。与邻近组织相比，LUAD组织中LINC00958的表达显著上调，可独立预测LUAD患者的不良生存。LINC00958敲低在体外和体内显著抑制LUAD细胞的生长和转移。LINC00958定位于细胞核，调节癌基因和代谢相关和免疫反应相关基因，并与组蛋白相互作用。LINC00958的靶标是TRPV3、STAP2和EDN2具有HOXA1、NANOG、FOSL2、JUN和ATF4基序的启动子。此外，HOXA1过表达减轻了LINC00958敲低诱导的致癌表型。在LINC00958的顺式元件处检测到的MYC/MAX基序反式激活了LINC00958启动子。MYC/MAX-反式激活的LINC00958通过募集HOXA1和诱导致癌重编程促进LUAD的恶性行为。