LncRNA LINC00839 promotes colorectal cancer progression by RUVBL1/Tip60-NRF1 signaling pathway. LncRNA LINC00839 promotes colorectal cancer progression by RUVBL1/Tip60-NRF1 signaling pathway

Purpose: we focused on the biological roles and mechanism of the lncRNA LINC00839 in CRC. Methods: In situ hybridization (ISH), and quantitative real-time PCR (qPCR) were used to detect the expression of LINC00839 in paired CRC specimen. Biological function of LINC00839 was determined in vitro and in vivo. Western blot, bioinformatics analysis, RNA pull-down, RNA immunoprecipitation (RIP) and chromatin immunoprecipitation assays (ChIP) were performed to identify the mechanisms underlying the functions of LINC00839 in CRC. Results: We found that LINC00839 was located in the nucleus of CRC cells and that LINC00839 was upregulated in CRC. High expression of LINC00839 was associated with poor outcome in CRC patients. Functionally, upregulation of LINC00839 promoted CRC cell proliferation, invasion, and metastasis in vitro and in vivo. Mechanistic investigations revealed that LINC00839 can promote the acetylation of histones H4K5 and H4K8 at the promoter of NRF1 after recruiting the RUVBL1/Tip60 complex, thereby upregulating the expression of NRF1. Subsequently, NRF1 served as an activator in mitochondrial metabolism and biogenesis, which, in turn, promoted CRC progression. Overall design: overexpressing LINCRNA CRC compared with control cell Transcriptomes

研究目的：本研究聚焦于长链非编码RNA（long non-coding RNA, lncRNA）LINC00839在结直肠癌（Colorectal Cancer, CRC）中的生物学功能与作用机制。实验方法：采用原位杂交（in situ hybridization, ISH）与定量实时聚合酶链反应（quantitative real-time PCR, qPCR）检测配对CRC组织标本中LINC00839的表达水平；通过体外及体内实验验证LINC00839的生物学功能；进一步通过蛋白质印迹（Western blot）、生物信息学分析、RNA下拉实验（RNA pull-down）、RNA免疫沉淀（RNA immunoprecipitation, RIP）及染色质免疫沉淀实验（chromatin immunoprecipitation assays, ChIP），探究LINC00839在CRC中发挥功能的潜在分子机制。研究结果：本研究发现，LINC00839定位于CRC细胞的细胞核内，且在CRC组织中表达显著上调；LINC00839高表达与CRC患者的不良预后密切相关。功能实验证实，LINC00839过表达可在体外及体内促进CRC细胞的增殖、侵袭与转移。机制研究揭示，LINC00839可通过招募RUVBL1/Tip60复合体，结合NRF1基因的启动子区域，介导组蛋白H4K5与H4K8的乙酰化修饰，从而上调NRF1的表达；后续研究证实，NRF1作为线粒体代谢与生物发生的激活因子，可进一步促进CRC的进展。实验整体设计：以过表达lncRNA的CRC细胞与对照细胞为研究对象，开展转录组（Transcriptomes）测序分析。