LncRNA LINC01270 aggravates the progression of gastric cancer through modulation of miR-326/EFNA3 axis

Gastric cancer (GC) is lethal malignancy, which is associated with high mortality. Long noncoding RNA LINC01270 has been identified to act as a potential oncogene in several cancers. However, its role and related regulatory mechanism in GC are yet to be illustrated. The levels of lncRNA LINC01270, miR-326, and EphrinA3 (EFNA3) were assessed by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8) and colony formation assays were applied for analyzing cell proliferation. Transwell assay was used for measuring cellular migration and invasion. Western blot analysis was employed for evaluating the protein levels. Luciferase reporter and RNA pull-down assays were utilized to verify the binding ability between LINC01270 (or EFNA3) and miR-326. Our findings indicated that LINC01270 expression was significantly up-regulated in GC tissues and cell lines. Additionally, LINC01270 knockdown attenuated GC progression through inhibiting cell proliferation, migration, and invasion. Functional experiments identified that lncRNA LINC01270 could positively regulate EFNA3 expression by serving as a competing endogenous RNA (ceRNA) for miR-326. Through rescue assays, inhibition of GC progression caused by LINC01270 suppression was found to be reversed by the application of miR-326 inhibitor or EFNA3 overexpression. Overall, our work demonstrated that lncRNA LINC01270 can accelerate cell proliferation, migration, and invasion via modulating miR-326/EFNA3 axis. These findings might implicate the potential role of lncRNA LINC01270 in GC treatment.

胃癌（Gastric cancer, GC）是一类致死性恶性肿瘤，具有较高的死亡率。长链非编码RNA LINC01270已被证实可在多种癌症中作为潜在癌基因发挥作用，但其在胃癌中的具体功能及相关调控机制仍有待阐明。本研究通过定量反转录聚合酶链反应（quantitative reverse transcriptase polymerase chain reaction, qRT-PCR）检测了长链非编码RNA LINC01270、微小RNA-326（miR-326）以及促红细胞生成素产生肝细胞受体配体A3（EphrinA3, EFNA3）的表达水平；采用细胞计数试剂盒-8（Cell counting kit-8, CCK-8）与集落形成实验分析细胞增殖能力；利用Transwell实验检测细胞迁移与侵袭能力；通过蛋白质免疫印迹（Western blot）分析评估蛋白表达水平。此外，本研究通过荧光素酶报告基因实验与RNA下拉实验验证了LINC01270（或EFNA3）与miR-326之间的靶向结合能力。研究结果显示，LINC01270在胃癌组织与细胞系中均呈显著高表达。敲低LINC01270可通过抑制胃癌细胞的增殖、迁移与侵袭能力，延缓胃癌进展。功能实验证实，长链非编码RNA LINC01270可作为微小RNA-326的内源竞争RNA（competing endogenous RNA, ceRNA），正向调控EFNA3的表达。通过挽救实验发现，miR-326抑制剂或EFNA3过表达可逆转LINC01270敲低所介导的胃癌进展抑制效应。综上，本研究证实长链非编码RNA LINC01270可通过调控miR-326/EFNA3轴，加速胃癌细胞的增殖、迁移与侵袭过程。上述研究结果提示，长链非编码RNA LINC01270有望成为胃癌治疗的潜在靶点。