Jiang Qingfeng, Xing Wenqun, Cheng Jinhua, Yu Yongkui
Department of Thoracic Surgery, The Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou, Henan 450008, People's Republic of China.
Onco Targets Ther. 2020 Jun 2;13:4919-4929. doi: 10.2147/OTT.S238808. eCollection 2020.
Long noncoding RNA X inactivate-specific transcript (lncRNA XIST) has been identified to contribute to the development and progression of non-small cell lung cancer (NSCLC). Thus, it is important to explore more specific functions and molecular mechanisms of XIST in NSCLC tumorigenesis.
The expression of XIST, microRNA (miR)-142-5p and paired box 6 (PAX6) was measured using quantitative real-time polymerase chain reaction or Western blot, respectively. Cell proliferation was analyzed using cell counting kit-8 (CCK-8) assay. Flow cytometry was utilized to measure apoptotic cells. Cell migration and invasion were determined by Transwell assay. The interaction between miR-142-5p and XIST or PAX6 was confirmed by the dual-luciferase reporter assay and RNA immunoprecipitation assay. In vivo experiments were performed through the murine xenograft model.
XIST was elevated in NSCLC, and XIST knockdown suppressed cell proliferation, migration, invasion and induced apoptosis in vitro as well as repressed tumor growth in vivo. MiR-142-5p was a target of XIST, and silencing miR-142-5p reversed the anti-tumor functions mediated by XIST knockdown in NSCLC cells. PAX6 was confirmed to be a target of miR-142-5p, and the inhibitory effects caused by miR-142-5p restoration in NSCLC cell malignant phenotypes were attenuated by PAX6 overexpression. Besides that, XIST could indirectly regulate PAX6 expression by sponging miR-142-5p in vivo and in vitro.
XIST suppresses cell tumorigenicity in human NSCLC by regulating miR-142-5p/PAX6 axis, which indicates a novel insight into the pathogenesis of NSCLC and lays a foundation for the molecular therapy of NSCLC.
长链非编码RNA X染色体失活特异性转录本（lncRNA XIST）已被证实与非小细胞肺癌（NSCLC）的发生发展有关。因此，探索XIST在NSCLC肿瘤发生中更具体的功能和分子机制具有重要意义。
分别采用定量实时聚合酶链反应或蛋白质免疫印迹法检测XIST、微小RNA（miR）-142-5p和配对盒基因6（PAX6）的表达。使用细胞计数试剂盒-8（CCK-8）检测法分析细胞增殖情况。采用流式细胞术检测凋亡细胞。通过Transwell检测法测定细胞迁移和侵袭能力。采用双荧光素酶报告基因检测法和RNA免疫沉淀检测法证实miR-142-5p与XIST或PAX6之间的相互作用。通过小鼠异种移植模型进行体内实验。
XIST在NSCLC中表达上调，敲低XIST可抑制体外细胞增殖、迁移、侵袭并诱导凋亡，同时在体内抑制肿瘤生长。miR-142-5p是XIST的靶标，沉默miR-142-5p可逆转XIST敲低介导的NSCLC细胞抗肿瘤功能。证实PAX6是miR-142-5p的靶标，PAX6过表达可减弱miR-142-5p恢复对NSCLC细胞恶性表型的抑制作用。此外，XIST可在体内和体外通过海绵吸附miR-142-5p间接调节PAX6表达。
XIST通过调节miR-142-5p/PAX6轴抑制人NSCLC细胞的肿瘤发生能力，这为NSCLC的发病机制提供了新的见解，并为NSCLC的分子治疗奠定了基础。
