RNA结合蛋白QKI可通过调节EMT相关基因转录物的切割形成circRNA促进胃癌的发生发展

The RNA binding protein QKI can promote gastric cancer by regulating cleavage of EMT-related gene transcripts to form circRNAs

目的通过生物信息学分析震颤响应蛋白(quaking,QKI)参与胃癌(gastric cancer,GC)发生和发展的可能分子机制。研究QKI在GC细胞中的增殖、侵袭和迁移能力。方法联合TCGA和GTEx数据库分析QKI在常见人类癌症样本中的差异表达。分析QKI蛋白表达与肿瘤突变负荷(tumor mutation burden,TMB)评分、微卫星不稳定性(microsatellite instability,MSI)评分以及ESTIMATE评分的相关性,并分析QKI蛋白表达与总生存期(overall survival,OS)、无病生存期(disease free survival,DFS)及无进展生存期(progression free survival,PFS)的相关性。通过生物信息学分析获得可编码DEcircRNAs的EMT相关基因,构建QKI-EMT-circRNAs调控网络。在TMK1细胞中对差异表达的circRNAs和EMT相关基因进行表达验证,并验证敲降QKI后对TMK1细胞的增殖、侵袭和迁移能力的影响。结果QKI在绝大多数肿瘤中差异表达,且与TMB、MSI以及肿瘤微环境(tumour microenvironment,TME)密切相关;QKI可作为高风险因子预测常见人类癌症患者的OS、DFS和PFS。QKI通过调控6个EMT相关基因转录本剪切形成8个circRNAs,它们均与胃癌患者预后明显相关。细胞实验表明,相对于正常胃上皮细胞,只有hsa_ccirc_0004015、CALD1和CDK14在TMK1细胞中表达下调。敲降QKI可抑制TMK1细胞的增殖、侵袭和迁移能力。结论QKI通过调控6个EMT相关基因转录本剪切形成circRNAs,从而促进GC发生和发展。QKI在TMK1细胞中高表达,敲降QKI可抑制TMK1细胞的增殖、侵袭和迁移能力。

Aim To study the proliferation,invasion and migration ability of Quaking(QKI)in gastric cancer(GC)via elucidating the molecular mechanisms associated with QKI in the occurrence and development of GC through bioinformatics.Methods Differential expression analysis of QKI was performed across various human cancer samples by merging data from the TCGA and GTEx databases.The correlation was analyzed between QKI protein expression and tumor mutation burden(TMB)score,microsatellite instability(MSI)score,and ESTIMATE score,and the correlation was also explored between QKI protein expression and overall survival(OS),disease free survival(DFS),and progression free survival(PFS).EMT related genes that could encode DECircRNAs were obtained through bioinformatics analysis to construct a QKI-EMT-circRNAs regulatory network.The differentially expressed circRNAs and EMT related genes in TMK1 cells were verified.The proliferation,invasion and migration ability of the QKI was studied by using the knockdown system.Results QKI was differentially expressed in the vast majority of tumors and was closely related to TMB,MSI,and tumor microenvironment(TME);QKI emerged as a high-risk factor for predicting OS,DFS,and PFS in individuals with common human cancers.QKI regulated the splicing of 6 EMT related gene transcripts to form eight circRNAs,all of which were significantly associated with the prognosis of gastric cancer patients.Cell experiments showed that compared to normal gastric epithelial cells,only hsa_ccirc_0004015,CALD1,and CDK14 were down-regulated in TMK1 cells.Knocking down QKI inhibited the proliferation,invasion and migration ability of TMK1 cells.Conclusion QKI exerts regulatory control over the transcription of six EMT-related genes,resulting in the formation of circRNAs,thereby promoting the pathogenesis and progression of GC.QKI is highly expressed in TMK1 cells,and knockdown of QKI can inhibit the proliferation,invasion and migration ability of TMK1 cells.