Cheng Zhiyi, Liu Guiyuan, Huang Chuanjiang, Zhao Xiaojun
Department of Gastrointestinal surgery, Hospital Afiliated 5 to Nantong University (Taizhou People's Hospital), Taizhou, 225300, PR China.
NPJ Genom Med. 2021 Sep 21;6(1):75. doi: 10.1038/s41525-021-00207-7.
Cancer cell autophagy has been associated with the progression of gastric cancer (GC), but involvement of long noncoding RNAs (lncRNAs) remains unclear. Initial bioinformatics analysis has identified abnormally highly expressed KLF5 in GC, as well as the predicted regulatory mechanism associating with lncRNA DANCR, miR-194, and AKT2. The expression of KLF5, DANCR, and AKT2 in GC tissue was upregulated, and the expression of miR-194 was downregulated. We knocked KLF5 down and manipulated the expression of DANCR, miR-194, and AKT2 to characterize their roles in GC cell viability, autophagy, and apoptosis. The mechanistic investigations revealed that KLF5 activated the transcription of DANCR in the promoter region and elevated its expression. DANCR acted as a miR-194 sponge to repress its expression in GC. MiR-194 targeted and inhibited AKT2 expression. Silencing KLF5 augmented GC cell autophagy, apoptosis and impeded its viability through the DANCR/miR-194/AKT2 axis. The tumor-inhibiting properties of KLF5 knockdown were substantiated in vivo. Together, our study uncovered the oncogenic role of KLF5-dependent lncRNA DANCR transcription in GC in vivo and in vitro, which implicates the miR-194/AKT2 axis in tumor growth regulation, and it may be a potential therapeutic target for human GC.
癌细胞自噬与胃癌(GC)的进展相关,但长链非编码RNA(lncRNA)的作用仍不清楚。初步生物信息学分析已确定GC中KLF5异常高表达,以及与lncRNA DANCR、miR-194和AKT2相关的预测调控机制。GC组织中KLF5、DANCR和AKT2的表达上调,而miR-194的表达下调。我们敲低KLF5并调控DANCR、miR-194和AKT2的表达,以表征它们在GC细胞活力、自噬和凋亡中的作用。机制研究表明,KLF5激活启动子区域DANCR的转录并提高其表达。DANCR作为miR-194的海绵,抑制其在GC中的表达。miR-194靶向并抑制AKT2的表达。沉默KLF5通过DANCR/miR-194/AKT2轴增强GC细胞自噬、凋亡并阻碍其活力。KLF5敲低的抑瘤特性在体内得到证实。总之,我们的研究揭示了KLF5依赖性lncRNA DANCR转录在体内外GC中的致癌作用,这表明miR-194/AKT2轴参与肿瘤生长调控,它可能是人类GC的潜在治疗靶点。