LncRNA NR-037939调控SIRT1影响糖代谢重编程促进胃癌进程的机制研究

Long noncoding RNA plays an important role in tumor progression. Our previous study identified a new lncRNA, named lncRNA NR-037939, which is highly expressed in gastric cancer and significantly correlated with the malignant phenotype of gastric cancer. Moreover, we confirmed that lncRNA NR-037939 promotes the growth and metastasis of gastric cancer in vitro and in vivo. However, the detailed mechanism need to be clarified. Furthermore, RNA-seq and pathway analysis indicate that NR-037939 is involved in the pathway of glucose metabolism and regulates the expression of SIRT1, a key regulated gene for glycometabolism. Based on these interesting findings, we hypothesized that lncRNA NR-037939 may promote the progression of gastric cancer through SIRT1-mediated reprogramming of glucose metabolism. This project intends to first confirm the critical role of NR-037939 in the regulation of glucose metabolism reprogramming by promoting glycolysis and inhibiting oxidative phosphorylation of gastric cancer cells in vitro and in vivo. Using overexpression / silencing experiments, we aim to testify the effect of SIRT1 mediated glycometabolism on the regulated malignant phenotype of gastric cancer cells, and then dissect the detailed molecular mechanism to explore the upstream and downstream signaling pathway of lncRNA NR-037939. Finally, we verify the important role of lncRNA NR-037939 on the progression of gastric cancer by regulating SIRT1 mediated glycometabolism in mouse model and clinical samples of gastric cancer. This project will provide the new insight into the mechanistic regulation of this new lncRNA NR-037939 on the progression of gastric cancer.

长链非编码RNA在肿瘤进展中发挥重要作用。我们前期研究鉴定出一条新的lncRNA NR-037939，其表达激活与胃癌恶性表型高度相关。体内外实验证实NR-037939促进胃癌肿瘤生长转移，但机制未知。进一步的RNA-seq及通路分析显示，NR-037939参与糖代谢途径并调控糖能量代谢关键因子SIRT1的表达。因此提出假设：NR-037939可能通过SIRT1介导的糖代谢重编程促进胃癌进展。本项目拟首先从体内外模型证实NR-037939调控胃癌细胞糖代谢重编程（促进糖酵解、抑制氧化磷酸化）的关键作用；体外过表达/沉默实验确定NR-037939调控SIRT1介导的糖代谢异常对胃癌细胞恶性表型的影响，并鉴定NR-037939调控作用的上下游分子机制。最后结合动物模型及临床样本明确NR-037939在调控糖代谢促进胃癌进程中的作用机制。该研究有望揭示胃癌相关lncRNA调控胃癌进展的新机制。

胃癌的发病率和死亡率均处于消化道恶性肿瘤首位。长非编码RNA（lncRNAs) 通过表观遗传调控、转录调节及翻译微肽或蛋白质等机制广泛参与胃癌细胞的增殖、侵袭转移、凋亡、免疫和耐药等生物学过程，在胃癌诊断、靶向治疗和预后等方面具有广阔前景。本研究中，长链非编码RNA（NR-037939）的Refseq号更新为NR-037940.1，来源于HOXA10-HOXA9 readthrough long non-coding RNA 基因，采用命名为lnc HOXA10-HOXA9。本研究筛选出lnc HOXA10-HOXA9在胃癌中表达上调并与胃癌进展相关。体内外实验表明该长链促进胃癌细胞增殖和迁移侵袭能力。结合线上数据库预测、内外源性验证及蛋白质谱等方法证实该lncRNA可编码112aa的小蛋白HDSP（lnc HOXA10-HOXA9-Directed Small Protein）。Western blot 检测并结合临床病理资料分析表明HDSP 在胃癌组织中显著上调，且与胃癌患者肿瘤大小、肿瘤分期及淋巴结转移呈正相关。敲降HDSP后胃癌细胞增殖和转移能力受损。免疫共沉淀、蛋白质谱、免疫荧光、RNA-seq、染色质免疫沉淀和双荧光素酶报告基因实验表明HDSP与MECOM结合并在翻译后水平拮抗 MECOM 的泛素-蛋白酶体降解途径维持其蛋白稳定性，进而激活SPINK1-EGFR信号通路促进胃癌进程。 lnc HOXA10-HOXA9通过编码调控蛋白HDSP激活 MECOM-SPINK1-EGFR 分子轴，促进胃癌细胞的增殖和转移，从而加速胃癌进程，有望作为胃癌诊断、治疗和预后评估的潜在分子靶标。