Department of Otolaryngology, Jining First People's Hospital of Shandong Province, Jining, Shandong, China.
Department of Otolaryngology, The Third People's Hospital, Qingdao, Shandong, China.
Biosci Rep. 2020 Apr 30;40(4). doi: 10.1042/BSR20193172.
X inactivate-specific transcript (XIST) is an attractive long noncoding RNA (lncRNA) functioning as an indicator of various human tumors, including laryngeal squamous cell carcinoma (LSCC). The present study was conducted to explore a novel regulatory network of lncRNA XIST in LSCC cells.
Quantitative real-time polymerase chain reaction (QRT-PCR) was used to detect the expression levels of XIST, miR-125b-5p and TRIB2 in LSCC cells and tissues. Cell proliferation, apoptosis, migration and invasion were detected by Cell Counting Kit-8 (CCK-8), flow cytometry and Transwell assays, separately. The relationship among XIST, miR-125b-5p and tribbles homolog 2 (TRIB2) was predicted by starBase v2.0 or TargetScan and confirmed by Dual-luciferase reporter assay. The TRIB2 protein expression was quantified by Western blot assay. Murine xenograft model was utilized to validate the role of XIST in vivo.
XIST was notably up-regulated in LSCC tissues and cells, and the high level of XIST was associated with the low survival rate of LSCC patients. XIST knockdown markedly repressed cell proliferation, migration and invasion and promoted the apoptosis of LSCC cells and the effects were antagonized by loss of miR-125b-5p. MiR-125b-5p was a target of XIST in LSCC cells, and it could bind to TRIB2 as well. Moreover, XIST-loss-induced down-regulation of TRIB2 could be significantly reversed by miR-125b-5p knockdown. XIST promoted the growth of LSCC tumor in vivo.
LncRNA XIST promoted the malignance of LSCC cells partly through competitively binding to miR-125b-5p, which in turn increased TRIB2 expression.
X 失活特异性转录物（XIST）是一种有吸引力的长非编码 RNA（lncRNA），可作为各种人类肿瘤的标志物，包括喉鳞状细胞癌（LSCC）。本研究旨在探讨 LSCC 细胞中 lncRNA XIST 的新型调控网络。
采用实时定量聚合酶链反应（QRT-PCR）检测 LSCC 细胞和组织中 XIST、miR-125b-5p 和 TRIB2 的表达水平。分别通过细胞计数试剂盒-8（CCK-8）、流式细胞术和 Transwell 测定法检测细胞增殖、凋亡、迁移和侵袭。通过 starBase v2.0 或 TargetScan 预测 XIST、miR-125b-5p 和 tribbles 同源物 2（TRIB2）之间的关系，并通过双荧光素酶报告基因测定法进行验证。通过 Western blot 测定法测定 TRIB2 蛋白表达。利用小鼠异种移植模型验证 XIST 在体内的作用。
XIST 在 LSCC 组织和细胞中明显上调，高水平的 XIST与 LSCC 患者的低生存率相关。XIST 敲低显著抑制 LSCC 细胞的增殖、迁移和侵袭，并促进细胞凋亡，而 miR-125b-5p 的缺失则拮抗了这些作用。miR-125b-5p 是 LSCC 细胞中 XIST 的靶标，也可以与 TRIB2 结合。此外，miR-125b-5p 敲低可显著逆转 XIST 缺失诱导的 TRIB2 下调。XIST 在体内促进 LSCC 肿瘤的生长。
lncRNA XIST 通过竞争性结合 miR-125b-5p 促进 LSCC 细胞的恶性转化，进而增加 TRIB2 的表达。
