Xie Yuanyuan, Wang Li, Yang Danfen
Department of Geriatrics, Affiliated Hospital of Yan'an University, Yan'an 716000, Shaanxi, People's Republic of China.
Department of Respiratory Medicine, Affiliated Hospital of Yan'an University, Yan'an 716000, Shaanxi, People's Republic of China.
Cancer Manag Res. 2020 Aug 4;12:6827-6836. doi: 10.2147/CMAR.S252893. eCollection 2020.
The high expression of circular RNA circEPSTI1 (hsa_circRNA_000479) has been reported to be associated with the malignant potential of ovarian cancer cells and triple-negative breast cancer cells. However, the expression profile and function of circEPSTI1 in non-small cell lung cancer (NSCLC) are not fully addressed.
Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to measure the RNA expression of circEPSTI1, relevant microRNAs (miRNAs) and high mobility group box 3 (HMGB3) in NSCLC tissues and cells. Cell counting kit 8 (CCK8) assay, colony formation and transwell assays were conducted to detect the capacities of proliferation, colony formation and metastasis in NSCLC cells. Western blot assay was performed to detect the expression of metastasis-associated proteins and HMGB3. Animal experiment was carried out to confirm the function of circEPSTI1 in vivo. The combination between miR-145 and circEPSTI1 or HMGB3 was verified by dual-luciferase reporter assay, RNA pull-down and RIP assays.
CircEPSTI1 was abnormally up-regulated in NSCLC tissues and cells in comparison with that in normal tissues and cells. The high expression of circEPSTI1 was associated with the low survival rate of NSCLC patients. CircEPSTI1 accelerated the proliferation, colony formation and motility of NSCLC cells in vitro. CircEPSTI1 silencing restrained the NSCLC tumor growth in vivo. miR-145 was validated as a target of circEPSTI1 in NSCLC cells. HMGB3 was a direct downstream target of miR-145 in NSCLC cells. The decreased abilities of proliferation, colony formation and metastasis caused by the silencing of circEPSTI1 were reversed by the depletion of miR-145 or the accumulation of HMGB3 in NSCLC cells.
CircEPSTI1 aggravated the progression of NSCLC through elevating the expression of HMGB3 via sponging miR-145.
据报道，环状RNA circEPSTI1（hsa_circRNA_000479）的高表达与卵巢癌细胞和三阴性乳腺癌细胞的恶性潜能相关。然而，circEPSTI1在非小细胞肺癌（NSCLC）中的表达谱和功能尚未完全明确。
应用定量实时聚合酶链反应（qRT-PCR）检测NSCLC组织和细胞中circEPSTI1、相关微小RNA（miRNA）和高迁移率族蛋白B3（HMGB3）的RNA表达。采用细胞计数试剂盒8（CCK8）检测、集落形成实验和Transwell实验检测NSCLC细胞的增殖、集落形成和转移能力。通过蛋白质免疫印迹实验检测转移相关蛋白和HMGB3的表达。进行动物实验以证实circEPSTI1在体内的功能。通过双荧光素酶报告基因实验、RNA下拉实验和RNA免疫沉淀实验验证miR-145与circEPSTI1或HMGB3之间的结合。
与正常组织和细胞相比，circEPSTI1在NSCLC组织和细胞中异常上调。circEPSTI1的高表达与NSCLC患者的低生存率相关。circEPSTI1在体外促进NSCLC细胞的增殖、集落形成和迁移。circEPSTI1沉默抑制了体内NSCLC肿瘤的生长。miR-145被证实为NSCLC细胞中circEPSTI1的靶点。HMGB3是NSCLC细胞中miR-145的直接下游靶点。circEPSTI1沉默导致的增殖、集落形成和转移能力下降被NSCLC细胞中miR-145的缺失或HMGB3的积累所逆转。
circEPSTI1通过海绵吸附miR-145提高HMGB3的表达，从而加重NSCLC的进展。
