长链非编码 RNA linc00673 通过海绵吸附 miR-150-5p 调控非小细胞肺癌增殖、迁移、侵袭和上皮间质转化。

BACKGROUND: The function of a new long non-coding RNA linc00673 remains unclear. While identified as an oncogenic player in non-small cell lung cancer (NSCLC), linc00673 was found to be anti-oncogenic in pancreatic ductal adenocarcinoma (PDAC). However whether linc00673 regulated malignancy and epithelial mesenchymal transition (EMT) has not been characterized. METHODS: Cell proliferation was assessed using CCK-8 and EdU assays, and cell migration and invasion were assessed using scratch assays and transwell invasion assays. Epithelial mesenchymal transition was examined using western blot, qRT-PCR and immunofluorescence staining. Interaction between miRNA and linc00673 was determined using luciferase reporter assays. In vivo experiments were performed to assess tumor formation. In addition, the expression data of NSCLC specimens of TCGA and patient survival data were utilized to explore the prognostic significance of linc00673. RESULTS: In the present study, we found high linc00673 expression was associated with poor prognosis of NSCLC patients. In vitro experiments showed linc00673 knockdown reversed TGF-β induced EMT, and miR-150-5p was predicted to target linc00673 through bioinformatics tools. Overexpression of miR-150-5p suppressed lin00673's expression while inhibition of miR-150-5p led to significant upregulation of lin00673, suggesting that linc00673 could be negatively regulated by miR-150-5p, which was further confirmed by the inverse correlation between linc00673 and miR-150-5p in NSCLC patients' specimen. Furthermore, we proved that miR-150-5p could directly target linc00673 through luciferase assay, so linc00673 could sponge miR-150-5p and modulate the expression of a key EMT regulator ZEB1 indirectly. In addition, miR-150-5p inhibition abrogated linc00673 silence mediated proliferation, migration, invasion and EMT suppressing effect. Moreover, the inhibition of linc00673 significantly attenuated the tumorigenesis ability of A549 cells in vivo. CONCLUSIONS: We validated linc00673 as a novel oncogenic lncRNA and demonstrated the molecular mechanism by which it promotes NSCLC, which will advance our understanding of its clinical significance.

背景：新的长非编码 RNA linc00673 的功能尚不清楚。虽然在非小细胞肺癌（NSCLC）中被鉴定为致癌因子，但在胰腺导管腺癌（PDAC）中发现 linc00673 具有抗癌作用。然而，linc00673 是否调节恶性肿瘤和上皮间质转化（EMT）尚未得到表征。

方法：使用 CCK-8 和 EdU 测定法评估细胞增殖，使用划痕测定法和 Transwell 侵袭测定法评估细胞迁移和侵袭。使用 Western blot、qRT-PCR 和免疫荧光染色法检测上皮间质转化。使用荧光素酶报告测定法确定 miRNA 与 linc00673 之间的相互作用。进行体内实验以评估肿瘤形成。此外，还利用 TCGA 的 NSCLC 标本的表达数据和患者生存数据来探讨 linc00673 的预后意义。

结果：本研究发现高 linc00673 表达与 NSCLC 患者的预后不良相关。体外实验表明，linc00673 敲低逆转了 TGF-β诱导的 EMT，并且通过生物信息学工具预测 miR-150-5p 可以靶向 linc00673。miR-150-5p 的过表达抑制 linc00673 的表达，而 miR-150-5p 的抑制导致 linc00673 的显著上调，表明 linc00673 可被 miR-150-5p 负调控，这在 NSCLC 患者标本中 linc00673 和 miR-150-5p 之间的负相关关系进一步证实了这一点。此外，我们通过荧光素酶测定法证明 miR-150-5p 可以直接靶向 linc00673，因此 linc00673 可以海绵 miR-150-5p 并间接调节 EMT 关键调节因子 ZEB1 的表达。此外，miR-150-5p 抑制消除了 linc00673 沉默介导的增殖、迁移、侵袭和 EMT 抑制作用。此外，抑制 linc00673 显著减弱了 A549 细胞在体内的致瘤能力。

结论：我们验证了 linc00673 是一种新的致癌 lncRNA，并证明了它促进 NSCLC 的分子机制，这将提高我们对其临床意义的理解。