Department of Geriatric Surgery, The First Affiliated Hospital of Xi'an Jiaotong University , Xi'an, China.
Cell Cycle. 2020 Oct;19(19):2519-2529. doi: 10.1080/15384101.2020.1809259. Epub 2020 Sep 16.
Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death, and radiotherapy is currently one of the main treatments. Long non-coding RNAs (lncRNAs) are associated with the radiosensitivity and tumorigenesis of HCC. However, the role and molecular mechanism of potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (KCNQ1OT1) in HCC are still unclear. The relative expression of KCNQ1OT1, microRNA-146a-5p (miR-146a-5p) and alkaline ceramidase 3 (ACER3) was quantified by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Clonogenic assay was used to assess the radiosensitivity of cells. Cell apoptosis and metastasis were evaluated by flow cytometry and transwell assays, respectively. The protein levels of apoptosis markers, metastasis markers and ACER3 were detected by western blot (WB) analysis. The relationship between miR-146a-5p and KCNQ1OT1 or ACER3 was determined by dual-luciferase reporter assay. Additionally, animal experiments were carried out to explore the effect of KCNQ1OT1 silencing on HCC tumor growth . KCNQ1OT1 was highly expressed in HCC, and its knockdown hindered the proliferation and metastasis, while increased the radiosensitivity and apoptosis of HCC cells. MiR-146a-5p could interact with KCNQ1OT1, and its inhibition reversed the effects of silenced-KCNQ1OT1 on the radiosensitivity and tumorigenesis of HCC cells. Besides, ACER3 was a target of miR-146a-5p, and its overexpression inversed the effects of miR-146a-5p mimic on the radiosensitivity and tumorigenesis of HCC cells. The expression of ACER3 was regulated by KCNQ1OT1 and miR-146a-5p. Furthermore, KCNQ1OT1 also could reduce the growth of HCC by regulating the miR-146a-5p/ACER3 axis . Our study suggested that KCNQ1OT1 improved ACER3 expression to regulate the radiosensitivity and tumorigenesis of HCC through sponging miR-146a-5p, indicating that KCNQ1OT1 might be a new therapeutic target for HCC.
肝细胞癌（HCC）是癌症相关死亡的第三大原因，目前放射治疗是主要治疗方法之一。长链非编码 RNA（lncRNA）与 HCC 的放射敏感性和肿瘤发生有关。然而，钾电压门控通道亚家族 Q 成员 1 重叠转录本 1（KCNQ1OT1）在 HCC 中的作用和分子机制尚不清楚。通过实时定量聚合酶链反应（qRT-PCR）定量了 KCNQ1OT1、微小 RNA-146a-5p（miR-146a-5p）和碱性 ceramidase 3（ACER3）的相对表达。通过 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四唑溴盐（MTT）测定细胞增殖。克隆形成试验用于评估细胞的放射敏感性。通过流式细胞术和 Transwell 测定分别评估细胞凋亡和转移。通过 Western blot（WB）分析检测凋亡标志物、转移标志物和 ACER3 的蛋白水平。通过双荧光素酶报告基因测定确定 miR-146a-5p 与 KCNQ1OT1 或 ACER3 的关系。此外，进行动物实验以探讨沉默 KCNQ1OT1 对 HCC 肿瘤生长的影响。KCNQ1OT1 在 HCC 中高表达，其敲低抑制 HCC 细胞的增殖和转移，同时增加 HCC 细胞的放射敏感性和凋亡。miR-146a-5p 可与 KCNQ1OT1 相互作用，其抑制逆转沉默-KCNQ1OT1 对 HCC 细胞放射敏感性和肿瘤发生的影响。此外，ACER3 是 miR-146a-5p 的靶标，其过表达逆转 miR-146a-5p 模拟物对 HCC 细胞放射敏感性和肿瘤发生的影响。ACER3 的表达受 KCNQ1OT1 和 miR-146a-5p 的调节。此外，KCNQ1OT1 还可以通过调节 miR-146a-5p/ACER3 轴来抑制 HCC 的生长。我们的研究表明，KCNQ1OT1 通过海绵 miR-146a-5p 提高 ACER3 的表达来调节 HCC 的放射敏感性和肿瘤发生，表明 KCNQ1OT1 可能成为 HCC 的新治疗靶点。
