Department of Oncology, Linyi Central Hospital, No. 17 Jiankang Road, Linyi, Shandong, China.
Department of General Surgery, Linyi Central Hospital, No. 17 Jiankang Road, Linyi, Shandong, China.
J Biochem. 2020 Jan 1;167(1):55-65. doi: 10.1093/jb/mvz078.
Accumulating researches have confirmed that circRNA abnormal expression plays a prominent role in the progression of colorectal cancer (CRC). The role of circ_0000218 in CRC and its potential mechanism are not clear. In this study, real-time polymerase chain reaction (RT-PCR) was employed to measure the circ_0000218, miR-139-3p and RAB1A mRNA expression in CRC tissues and cells. Immunohistochemistry and western blot were conducted to determine the RAB1A expression in CRC tissues and cells, respectively. Colony formation assay and BrdU method were employed to monitor the effect of circ_0000218 on cell proliferation. Transwell assay was adopted to detect cell migration and invasion. Dual luciferase reporter assay and RNA immunoprecipitation assay were adopted to confirm the targeting relationship between circ_0000218 and miR-139-3p, miR-139-3p and RAB1A. We demonstrated that circ_0000218 was notably upregulated in CRC tissues and cell lines, and its high expression level was markedly linked to the increase of T staging and local lymph node metastasis. Circ_0000218 overexpression enhanced the proliferation and metastasis of CRC cells while knocking down circ_0000218 caused the opposite effects. We also observed that miR-139-3p was negatively regulated by circ_0000218, while RAB1A was positively regulated by it. Collectively, this study suggested that circ_0000218 upregulated RAB1A and promoted CRC proliferation and metastasis via sponging miR-139-3p.
越来越多的研究证实 circRNA 异常表达在结直肠癌（CRC）的进展中起着重要作用。circ_0000218 在 CRC 中的作用及其潜在机制尚不清楚。在本研究中，采用实时聚合酶链反应（RT-PCR）测量 CRC 组织和细胞中的 circ_0000218、miR-139-3p 和 RAB1A mRNA 表达。免疫组织化学和 Western blot 分别用于确定 CRC 组织和细胞中的 RAB1A 表达。集落形成实验和 BrdU 法用于监测 circ_0000218 对细胞增殖的影响。Transwell 测定法用于检测细胞迁移和侵袭。双荧光素酶报告基因测定法和 RNA 免疫沉淀测定法用于证实 circ_0000218 与 miR-139-3p、miR-139-3p 与 RAB1A 之间的靶向关系。我们表明 circ_0000218 在 CRC 组织和细胞系中显著上调，其高表达水平与 T 分期和局部淋巴结转移的增加显著相关。circ_0000218 的过表达增强了 CRC 细胞的增殖和转移，而敲低 circ_0000218 则产生相反的效果。我们还观察到 miR-139-3p 被 circ_0000218 负调控，而 RAB1A 被其正调控。综上所述，这项研究表明 circ_0000218 通过海绵吸附 miR-139-3p 而上调 RAB1A，促进 CRC 的增殖和转移。
