Xu Haitao, Miao Jing, Liu Shuai, Liu Hongjian, Zhang Lianguo, Zhang Qingguang
Department of Thoracic Surgery, Binzhou Medical University Hospital, Binzhou, Shandong 256603, China.
Department of Pediatrics, Binzhou People's Hospital, Binzhou, Shandong 256603, China.
Clinics (Sao Paulo). 2021 Apr 26;76:e2175. doi: 10.6061/clinics/2021/e2175. eCollection 2021.
The long non-coding RNA (lncRNA) KCNQ1 overlapping transcript 1 (KCNQ1OT1) exerts vital regulatory functions in diverse tumors. However, the biological function of KCNQ1OT1 in esophageal squamous cell carcinoma (ESCC) remains unclear.
KCNQ1OT1 expression was detected in ESCC tissues using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis, migration, and invasion were detected by the CCK-8 assay, EdU assay, flow cytometry analysis, and Transwell experiments, respectively. Bioinformatics analysis, luciferase reporter experiments, and RNA immunoprecipitation assays were used to predict and validate the regulatory relationships between KCNQ1OT1, microRNA-133b (miR-133b) and epidermal growth factor receptor (EGFR).
KCNQ1OT1 expression was remarkably upregulated in ESCC tissues and cell lines. Overexpression of KCNQ1OT1 markedly promoted ESCC cell proliferation, migration, and invasion and enhanced the expression of N-cadherin, MMP-2, and MMP-9, but inhibited apoptosis and E-cadherin expression in ESCC cell lines; KCNQ1OT1 knockdown exerted the opposite effects. KCNQ1OT1 could directly bind to miR-133b and suppress its expression, and miR-133b reversed the effects of KCNQ1OT1 overexpression in ESCC cells. MiR-133b reduced the expression of epidermal growth factor receptor (EGFR); further, KCNQ1OT1 activated the phosphatidylinositol 3-kinase/AKT serine/threonine kinase 1 (PI3K/AKT) signaling pathway by repressing miR-133b repression and indirectly upregulating EGFR. KCNQ1OT1 expression was positively correlated with EGFR mRNA expression and negatively correlated with miR-133b expression.
KCNQ1OT1 facilitates ESCC progression by sponging miR-133b and activating the EGFR/PI3K/AKT pathway.
长链非编码RNA（lncRNA）KCNQ1重叠转录本1（KCNQ1OT1）在多种肿瘤中发挥重要调控作用。然而，KCNQ1OT1在食管鳞状细胞癌（ESCC）中的生物学功能尚不清楚。
采用定量实时聚合酶链反应（qRT-PCR）检测ESCC组织中KCNQ1OT1的表达。分别通过CCK-8法、EdU法、流式细胞术分析和Transwell实验检测细胞增殖、凋亡、迁移和侵袭情况。利用生物信息学分析、荧光素酶报告基因实验和RNA免疫沉淀实验预测并验证KCNQ1OT1、微小RNA-133b（miR-133b）和表皮生长因子受体（EGFR）之间的调控关系。
KCNQ1OT1在ESCC组织和细胞系中表达明显上调。KCNQ1OT1过表达显著促进ESCC细胞增殖、迁移和侵袭，增强N-钙黏蛋白、基质金属蛋白酶-2（MMP-2）和基质金属蛋白酶-9的表达，但抑制ESCC细胞系中的细胞凋亡和E-钙黏蛋白表达；敲低KCNQ1OT1则产生相反的效果。KCNQ1OT1可直接与miR-133b结合并抑制其表达，且miR-133b可逆转KCNQ1OT1过表达对ESCC细胞的影响。MiR-133b降低表皮生长因子受体（EGFR）的表达；此外，KCNQ1OT1通过抑制miR-133b的抑制作用并间接上调EGFR来激活磷脂酰肌醇3-激酶/AKT丝氨酸/苏氨酸激酶1（PI3K/AKT）信号通路。KCNQ1OT1表达与EGFR mRNA表达呈正相关，与miR-133b表达呈负相关。
KCNQ1OT1通过吸附miR-133b并激活EGFR/PI3K/AKT通路促进ESCC进展。
