Laboratory of Cancer Cell Biology, Tianjin Cancer Research Institute, Tianjin Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China.
Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment, Tianjin Lung Cancer Institute, Tianjin Medical University General Hospital, Tianjin, China.
Thorac Cancer. 2019 Feb;10(2):128-136. doi: 10.1111/1759-7714.12911. Epub 2018 Nov 28.
The main cause of death in patients with non-small cell lung cancer (NSCLC) is the progression of cancer metastasis, which can be attributed to multiple factors, such as cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT). Long non-coding RNAs (lncRNAs) play important roles in the regulation of the cell cycle, cell proliferation, immune responses, and metastasis in cancers, but the potential roles and mechanisms of lincRNAs in CSC-like properties of cancer have not yet been elucidated.
Human NSCLC cell lines (A549 and H1299), highly metastatic cell lines (L9981 and 95D), and their corresponding low-metastatic cell lines (NL9980 and 95C) were subject to quantitative real-time PCR and Western blot, transwell invasion, colony formation, and wound healing assays.
Linc-ITGB1 was greatly upregulated in CSC spheres. Linc-ITGB1 knockdown markedly inhibited CSC formation and the expression of stemness-associated genes, such as Sox2, Nanog, Oct-4, c-Myc, and CD133. Depletion of linc-ITGB1 expression also inhibited the in vitro invasive and migratory potential of cells, and further analysis indicated that linc-ITGB1 knockdown increased the expression of the epithelial marker E-cadherin and downregulated the mesenchymal markers vimentin and fibronectin. The EMT-related transcription factor Snail mediated these effects of linc-ITGB1 in NSCLC, and overexpression of Snail significantly reversed the inhibitory effects of linc-ITGB1 depletion.
Overall, our study demonstrated that linc-ITGB1 promoted NSCLC cell EMT and cancer stemness by regulating Snail expression.
非小细胞肺癌（NSCLC）患者死亡的主要原因是癌症转移的进展，这可归因于多种因素，如癌症干细胞（CSC）和上皮-间充质转化（EMT）。长链非编码 RNA（lncRNA）在癌症中细胞周期、细胞增殖、免疫反应和转移的调控中发挥重要作用，但 lincRNA 在癌症 CSC 样特性中的潜在作用和机制尚未阐明。
对人 NSCLC 细胞系（A549 和 H1299）、高转移性细胞系（L9981 和 95D）及其相应的低转移性细胞系（NL9980 和 95C）进行实时定量 PCR 和 Western blot、transwell 侵袭、集落形成和划痕愈合测定。
Linc-ITGB1 在 CSC 球中高度上调。Linc-ITGB1 敲低显著抑制 CSC 形成和干性相关基因的表达，如 Sox2、Nanog、Oct-4、c-Myc 和 CD133。linc-ITGB1 表达的耗竭也抑制了细胞的体外侵袭和迁移潜能，进一步分析表明 linc-ITGB1 敲低增加了上皮标志物 E-钙黏蛋白的表达，并下调了间充质标志物波形蛋白和纤连蛋白。EMT 相关转录因子 Snail 介导了 linc-ITGB1 在 NSCLC 中的这些作用，Snail 的过表达显著逆转了 linc-ITGB1 耗竭的抑制作用。
总的来说，我们的研究表明 linc-ITGB1 通过调节 Snail 表达促进 NSCLC 细胞 EMT 和癌症干性。
