Department of Ophthalmology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China.
Eur Rev Med Pharmacol Sci. 2020 Oct;24(20):10433-10444. doi: 10.26355/eurrev_202010_23395.
Retinoblastoma (RB) is a frequent intraocular tumor in children. Long-non-coding RNA X inactive specific transcript (XIST) has been reported to participate in the RB process, while its potential role remains largely unknown.
The expression patterns of XIST, microRNA (miR)-361-3p, and Syntaxin 17 (STX17) were determined using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assay. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), flow cytometry, and transwell assays were employed to reckon cell viability, apoptosis, and mobility in RB cells, respectively. Besides, the levels of STX17 and autophagy-related proteins were detected utilizing Western blot. Dual-Luciferase reporter assay was implemented to evaluate the interaction between miR-361-3p and XIST or STX17, and the role of XIST in tumor growth was analyzed through xenograft tumor model.
The expression levels of XIST and STX17 were higher in RB tissues and cells, but miR-361-3p was downregulated. Loss of XIST was inversely connected with aggressive characteristics, showing as the curb of cell proliferation, migration, invasion, autophagy, and enhancement of apoptosis in RB cells. Also, the deficiency of XIST caused the decrease of tumor growth in vivo. Meanwhile, miR-361-3p inhibitor partially rescued XIST detection-mediated cell behaviors in vitro. Similarly, miR-361-3p mimic-mediated suppressive effect on aggressive phenotypes was abolished after overexpression of STX17 in RB cells. Mechanically, XIST was a sponge of miR-361-3p to regulate STX17.
XIST functioned as an oncogenic lncRNA via miR-361-3p/STX17 axis in the progression of RB, which might provide a promising theoretical basis for the clinical therapy of RB.
视网膜母细胞瘤(RB)是儿童中常见的眼内肿瘤。长链非编码 RNA X 失活特异性转录物(XIST)已被报道参与 RB 过程,但其潜在作用仍知之甚少。
采用定量实时聚合酶链反应(qRT-PCR)检测 XIST、microRNA(miR)-361-3p 和 Syntaxin 17(STX17)的表达模式。分别采用 3-(4,5-二甲基-2-噻唑基)-2,5-二苯基-2-H-四唑溴盐(MTT)、流式细胞术和 Transwell 测定法来计算 RB 细胞的细胞活力、凋亡和迁移。此外,还利用 Western blot 检测 STX17 和自噬相关蛋白的水平。双荧光素酶报告基因检测评估 miR-361-3p 与 XIST 或 STX17 的相互作用,通过异种移植肿瘤模型分析 XIST 在肿瘤生长中的作用。
XIST 和 STX17 在 RB 组织和细胞中的表达水平较高,而 miR-361-3p 下调。XIST 的缺失与侵袭性特征呈负相关,表现为 RB 细胞增殖、迁移、侵袭、自噬减少和凋亡增强。此外,XIST 缺失导致体内肿瘤生长减少。同时,在体外,miR-361-3p 抑制剂部分挽救了 XIST 检测介导的细胞行为。同样,在 RB 细胞中过表达 STX17 后,miR-361-3p 模拟介导的对侵袭表型的抑制作用被消除。机制上,XIST 通过 miR-361-3p/STX17 轴作为致癌 lncRNA 发挥作用。
XIST 通过 miR-361-3p/STX17 轴在 RB 的进展中发挥致癌 lncRNA 的作用,这可能为 RB 的临床治疗提供有希望的理论基础。