Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer. The abnormal expression of long noncoding RNAs (lncRNAs) can facilitate or suppress the development of malignant tumors. lncRNA actin alpha 2, smooth muscle antisense RNA 1 (ACTA2‐AS1) has been reported to function as a tumor suppressor in liver cancer, nevertheless, its influences on LUAD remain to be investigated. In this paper, ACTA2‐AS1 was identified as a downregulated lncRNA in LUAD samples and cells. Functionally, ACTA2‐AS1 overexpression restrained cell proliferation but accelerated cell apoptosis in LUAD. In addition, we determined the suppressive effect of ACTA2‐AS1 on LUAD cell invasion, migration, and epithelial–mesenchymal transition progress. Mechanistically, ACTA2‐AS1 exert functions as a competing endogenous RNA through serving as a sponge for microRNA‐378a‐3p (miR‐378a‐3p) and microRNA‐4428 (miR‐4428) to elevate SRY‐related high‐mobility group box 7 (SOX7) expression. Importantly, SOX7 silencing could recover the ACTA2‐AS1‐mediated cell functions. To summarize, ACTA2‐AS1 suppresses the malignant processes of LUAD cells through sequestering miR‐378a‐3p and miR‐4428 to augment SOX7 expression.

中文翻译：

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ACTA2-AS1通过隔离miR-378a-3p和miR-4428以提高SOX7表达来抑制肺腺癌的进展。

肺腺癌（LUAD）是肺癌最常见的组织学亚型。长非编码RNA（lncRNA）的异常表达可以促进或抑制恶性肿瘤的发展。lncRNA肌动蛋白alpha 2，平滑肌反义RNA 1（ACTA2-AS1）据报道在肝癌中起着抑癌作用，但是，它对LUAD的影响尚待研究。在本文中，ACTA2-AS1被鉴定为LUAD样品和细胞中的lncRNA下调。从功能上讲，ACTA2-AS1过表达抑制LUAD中的细胞增殖，但加速细胞凋亡。另外，我们确定了ACTA2-AS1对LUAD细胞侵袭，迁移以及上皮-间质转化过程的抑制作用。机械上，ACTA2-AS1通过充当microRNA‐378a‐3p（miR‐378a‐3p）和microRNA‐4428（miR‐4428）的海绵发挥作用，从而起到竞争内源性RNA的作用，从而提升了SRY相关的高迁移率小组7（SOX7） ）表达。重要的是，SOX7沉默可以恢复ACTA2-AS1介导的细胞功能。综上所述，ACTA2-AS1通过隔离miR-378a-3p和miR-4428来增强SOX7表达，从而抑制LUAD细胞的恶性过程。