Liu Yuqiang, Yao Kun, Zhang Ke, Wang Jianping, Dai Qiang, Wang Rong
Department of Emergency, Gansu Provincial Hospital 730000 Lanzhou Gansu China.
Department of Nuclear Medicine, Gansu Provincial Hospital 204 Donggangxi Road, Chengguan District 730000 Lanzhou Gansu China
RSC Adv. 2020 Jan 9;10(3):1711-1723. doi: 10.1039/c9ra08525d. eCollection 2020 Jan 7.
Gastric cancer (GC) is one of the common cancers worldwide. Emerging findings imply that aberrant expression of circular RNA_0003221 (circPTK2) is involved in GC. Nevertheless, the function of circPTK2 in GC needs more explanation. Profiles of circPTK2, microRNA (miR)-369-3p, and zinc finger E-box binding homeobox 1 (ZEB1) were determined by quantitative real-time polymerase chain reaction assay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry, and transwell assays were employed to estimate cell proliferation, apoptosis, and mobility in GC cells, respectively. Meanwhile, levels of ZEB1 and other indicated proteins were tested using western blot. Survival fraction was assessed utilizing clonogenic assay. Additionally, the role of circPTK2 in tumorigenesis was investigated a xenograft tumor model. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were conducted to confirm the interrelation between miR-369-3p and circPTK2 or ZEB1. Levels of circPTK2 and ZEB1 were markedly augmented, but miR-369-3p was downregulated in GC tissues and cells. CircPTK2 depletion restrained cell growth, metastasis, and epithelial-mesenchymal transition, and promoted radiosensitivity in GC cells. And circPTK2 depletion reduced tumor growth and metastasis . Moreover, the effect of circPTK2 silencing on cellular phenotypes and radiosensitivity was regained by miR-369-3p inhibitor. Furthermore, upregulation of ZEB1 could overturn miR-369-3p mimic-induced effect on cell metastasis and radiosensitivity of GC cells. Mechanically, circPTK2 was a sponge of miR-369-3p to separate ZEB1. CircPTK2/miR-369-3p/ZEB1 axis modulated cell behaviors and radiosensitivity in GC; thus circPTK2 might serve as a promising target for GC therapy.
胃癌（GC）是全球常见癌症之一。新出现的研究结果表明，环状RNA_0003221（circPTK2）的异常表达与胃癌有关。然而，circPTK2在胃癌中的功能仍需进一步阐释。通过定量实时聚合酶链反应检测来测定circPTK2、微小RNA（miR）-369-3p和锌指E盒结合同源框1（ZEB1）的表达情况。分别采用3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐、流式细胞术和Transwell实验来评估胃癌细胞的增殖、凋亡和迁移能力。同时，使用蛋白质免疫印迹法检测ZEB1和其他相关蛋白的水平。利用克隆形成实验评估存活分数。此外，通过异种移植肿瘤模型研究circPTK2在肿瘤发生中的作用。进行双荧光素酶报告基因、RNA免疫沉淀和RNA下拉实验以证实miR-369-3p与circPTK2或ZEB1之间的相互关系。在胃癌组织和细胞中，circPTK2和ZEB1水平显著升高，但miR-369-3p表达下调。circPTK2缺失抑制了胃癌细胞的生长、转移和上皮-间质转化，并提高了其放射敏感性。circPTK2缺失还减少了肿瘤的生长和转移。此外，miR-369-3p抑制剂可恢复circPTK2沉默对细胞表型和放射敏感性的影响。此外，ZEB1的上调可逆转miR-369-3p模拟物对胃癌细胞转移和放射敏感性的影响。机制上，circPTK2是miR-369-3p的海绵，可释放ZEB1。circPTK2/miR-369-3p/ZEB1轴调节胃癌细胞的行为和放射敏感性；因此，circPTK2可能是胃癌治疗的一个有前景的靶点。
