Department of General Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
Anticancer Drugs. 2022 Jan 1;33(1):e409-e422. doi: 10.1097/CAD.0000000000001221.
Colorectal cancer (CRC) is a prevalent malignant tumor with a poor prognosis. Circular RNA (circRNA) circ_0007334 is related to cell proliferation in CRC. This study is designed to explore the role and mechanism of circ_0007334 in CRC progression. Circ_0007334, microRNA-577 (miR-577) and kruppel-like factor 12 (KLF12) levels were measured by real-time quantitative PCR (RT-qPCR). Exosomes were detected by a transmission electron microscope and nanoparticle tracking analysis (NTA). CD63, TSG101, matrix metallopeptidase-2 (MMP-2), MMP-9, VEGFA and KLF12 protein levels were examined by western blot assay. The binding relationship between miR-577 and circ_0007334 or KLF12 was predicted by circRNA interactome or Starbase and verified by a dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Cell viability, colony number, migration, invasion and angiogenesis were detected by cell counting kit-8 (CCK-8), colony formation, wound healing, transwell and tube formation assays. The biological role of circ_0007334 was examined by the xenograft tumor model in vivo. Circ_0007334 and KLF12 were increased, and miR-577 was decreased in CRC tissues and cells. Also, circ_0007334 expression was upregulated in CRC cell-derived exosomes. Circ_0007334 deficiency repressed cell viability, colony formation, migration, invasion, and angiogenesis in CRC cells. Mechanically, circ_0007334 could regulate KLF12 expression by sponging miR-577. Circ_0007334 downregulation or exosomal circ_0007334 silencing blocked CRC tumor growth in vivo. These results presented that circ_0007334 deficiency exerts a tumor-suppressor by the miR-577/KLF12 axis in CRC, and indicated that exosomal circ_0007334 could hinder CRC tumor growth and angiogenesis in vivo. Our findings provided a novel therapeutic strategy for CRC.
结直肠癌（CRC）是一种预后不良的常见恶性肿瘤。环状 RNA（circRNA）circ_0007334 与 CRC 中的细胞增殖有关。本研究旨在探讨 circ_0007334 在 CRC 进展中的作用和机制。通过实时定量 PCR（RT-qPCR）测量 circ_0007334、微小 RNA-577（miR-577）和 Kruppel 样因子 12（KLF12）的水平。通过透射电子显微镜和纳米颗粒跟踪分析（NTA）检测外泌体。通过 Western blot 检测 CD63、TSG101、基质金属蛋白酶-2（MMP-2）、MMP-9、血管内皮生长因子 A（VEGFA）和 KLF12 蛋白水平。通过 circRNA 相互作用组或 Starbase 预测 miR-577 与 circ_0007334 或 KLF12 的结合关系，并通过双荧光素酶报告基因和 RNA 免疫沉淀（RIP）实验验证。通过细胞计数试剂盒-8（CCK-8）、集落形成、划痕愈合、Transwell 和管形成实验检测细胞活力、集落数、迁移、侵袭和血管生成。通过体内异种移植肿瘤模型研究 circ_0007334 的生物学作用。CRC 组织和细胞中 circ_0007334 和 KLF12 升高，miR-577 降低。此外，CRC 细胞来源的外泌体中 circ_0007334 的表达上调。circ_0007334 缺乏抑制 CRC 细胞的细胞活力、集落形成、迁移、侵袭和血管生成。从机制上讲，circ_0007334 通过海绵 miR-577 调节 KLF12 的表达。circ_0007334 下调或外泌体 circ_0007334 沉默阻断体内 CRC 肿瘤生长。这些结果表明，circ_0007334 通过 miR-577/KLF12 轴在 CRC 中发挥抑癌作用，并表明外泌体 circ_0007334 可在体内抑制 CRC 肿瘤生长和血管生成。我们的研究结果为 CRC 提供了一种新的治疗策略。
