The biological function of the long non-coding RNA endogenous born avirus-like nucleoprotein in lung adenocarcinoma is mediated through the microRNA-655-3p/B-cell lymphoma-2 axis

Lung adenocarcinoma (LUAD) is a subtype of lung cancer, and therapy remains a great challenge. A growing body of evidence shows that long-chain non-coding RNAs (lncRNAs) play an important role in the occurrence and development of LUAD. This study investigated the roles and mechanisms of action of EBLN3P in LUAD. The bioinformatics software starBase and TargetScan were used to predict the binding sites of the lncRNA endogenous born avirus-like nucleoprotein (EBLN3P) and microRNA (miR)-655-3p in LUAD. The regulatory role of EBLN3P and miR-655-3p in cell proliferation was verified through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2 H-tetrazolium bromide (MTT) assay. The binding sites between EBLN3P, miR-655-3p, and B-cell lymphoma-2 (Bcl-2) were assessed using dual-luciferase reporter assay, western blotting, and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Flow cytometry (FCM) was performed to analyze the apoptotic rates of A549 cells after transfection. The results revealed that EBLN3P was upregulated, whereas miR-655-3p was downregulated in LUAD cell lines (A549 and NCI-H23). Bioinformatics analysis and dual-luciferase reporter assays indicated that EBLN3P interacted with miR-655-3p. Knockdown of EBLN3P notably inhibited the bioactivity and induced apoptosis in A549 cells by upregulating miR-655-3p. Mechanistically, miR-655-3p inhibits cell viability and induces apoptosis by inhibiting Bcl-2 expression. The high expression of Bcl-2 reversed the impact of miR-655-3p on the inhibition of cell bioactivity and induction of apoptosis in A549 cells. In conclusion, this study demonstrated that EBLN3P silencing inhibits bioactivity and induces apoptosis via the miR-655-3p/Bcl-2 axis, providing a potential therapeutic target for lung adenocarcinoma.肺腺癌（Lung adenocarcinoma, LUAD）是肺癌的一种亚型，临床治疗仍面临巨大挑战。越来越多的研究证据表明，长链非编码RNA（long-chain non-coding RNAs, lncRNAs）在肺腺癌的发生与发展进程中发挥关键作用。本研究探讨了内源性博尔纳病毒样核蛋白（endogenous born avirus-like nucleoprotein, EBLN3P）在肺腺癌中的作用及分子机制。研究采用生物信息学软件starBase与TargetScan，预测了肺腺癌样本中EBLN3P与微小RNA（microRNA, miR）-655-3p的结合位点。通过3-(4,5-二甲基噻唑-2-基)-2,5-二苯基溴化四氮唑（3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide, MTT）实验，验证了EBLN3P与miR-655-3p对细胞增殖的调控功能。借助双荧光素酶报告基因实验、蛋白质印迹（western blotting）以及定量反转录聚合酶链反应（quantitative reverse transcription polymerase chain reaction, qRT-PCR），评估了EBLN3P、miR-655-3p与B细胞淋巴瘤-2（B-cell lymphoma-2, Bcl-2）之间的相互作用位点。采用流式细胞术（flow cytometry, FCM）分析转染后A549细胞的凋亡水平。结果显示，在肺腺癌细胞系A549与NCI-H23中，EBLN3P呈高表达状态，而miR-655-3p呈低表达状态。生物信息学分析与双荧光素酶报告基因实验证实，EBLN3P可与miR-655-3p直接结合。敲低EBLN3P可通过上调miR-655-3p的表达，显著抑制A549细胞的生物活性并诱导细胞凋亡。机制层面研究表明，miR-655-3p可通过抑制Bcl-2的表达，降低细胞活力并诱导细胞凋亡。高表达Bcl-2可逆转miR-655-3p对A549细胞生物活性的抑制作用，以及对细胞凋亡的诱导效应。综上，本研究证实，沉默EBLN3P可通过调控miR-655-3p/Bcl-2轴抑制细胞生物活性并诱导细胞凋亡，为肺腺癌的临床治疗提供了潜在的靶向方向。