APC基因相关lncRNAs早期诊断结直肠癌的应用价值及作用研究

Adenomatous polyposis (Adenomatous Polyposis Coli, APC) gene mutation proved to be an early event in the development of CRC, which plays important roles in the evolution of normal-adnoma-cancer. LncRNAs could regulate different biological processes and closely associate with tumor initation and progression. LncRNAs have been proved to be serected into serum by cells and expected to be potential diagnostic biomarkers. Therefore, we focused on APC gene to screen APC gene related lncRNAs that might provide a new way for CRC early detection. We previously found differential lncRNAs expression profile in CRC tissues using lncRNAs chip, and screened APC gene associated lncRNAs by bioinformatics, which were preliminary validated in SW480 and SW480APC (transfected with full-length APC) cells. On this basis, we will try to establish serum exosomes lncRNAs direct RT-qPCR detection methods, and evaluate the diagnostic value of colorectal cancer in clinical practice. And a series in vitro and in vivo studies will be carried out to explore potential mechanisms of CRC. This study will supplement the present early diagnositic methods and also beneficial to improve the molecular mechanisms of CRC.

结肠腺瘤样息肉（APC）基因突变是结直肠癌发生的早期事件，在正常细胞-腺瘤-结直肠癌演变过程中发挥重要作用。lncRNAs参与调控肿瘤细胞内多种生物学过程，与肿瘤发生发展密切相关，且可经细胞分泌到血清，是潜在的诊断标志物。因此，以APC基因为切入点，筛选APC基因相关lncRNAs有望为结直肠癌早期发现提供新的途径。课题组前期采用lncRNAs芯片筛选出结直肠癌组织差异lncRNAs，结合生物信息学分析APC基因相关lncRNAs，并在SW480和SW480APC（稳定转染全长APC）细胞中初步验证。现拟以exosomes为载体，建立血清exosomes lncRNAs直接RT-qPCR检测方法，评价相关lncRNAs对结直肠癌的诊断价值；同时通过体内外实验，探讨APC相关lncRNA在结直肠癌发生中的作用。本研究可对结直肠癌早期诊断方法进行有效补充，并有助于完善结直肠癌发生的分子机理。

APC基因突变是结直肠癌早期发生事件，前期研究发现APC可直接调节Wnt通路，在结直肠癌发生发展中具有重要作用。lncRNAs参与调控肿瘤细胞内多种生物学过程，不同肿瘤中存在不同的表达模式，可经细胞代谢分泌到血清中，深入研究lncRNAs有望发现用于肿瘤诊断、预后和治疗的新型标志物。本项目基于组织芯片筛选结果及SW480/SW480APC细胞lncRNA测序结果，生物信息学分析筛选差异lncRNAs；优化循环lncRNA检测技术，建立结直肠癌发生相关循环lncRNAs预测模型；发现lncRNA NR_027451在结直肠癌患者中高表达，且与疾病进展密切相关，血清水平检测有助于区分结直肠癌患者与健康对照和良性疾病患者；细胞功能实验表明其在结直肠癌细胞增殖、迁移和侵袭等方面具有重要作用。建立血清exosome lncRNA检测方法，应用RT-qPCR方法，检测结直肠癌患者组织、血清及外泌体中lncRNA CCAT2表达水平，结果表明其在结直肠癌患者血清中表达上调，术后水平明显下降，且血清与外泌体表达水平无显著性差异，提示外泌体lncRNA检测可作为结直肠癌潜在的生物标志物。本项目研究成果可为深入研究结直肠癌发生的分子机制及早期诊疗新靶点提供依据。