Nuclear Medicine Laboratory, Tangshan People's Hospital, Lunan District, Tangshan City, Hebei Province, China.
Eur Rev Med Pharmacol Sci. 2020 Apr;24(8):4190-4202. doi: 10.26355/eurrev_202004_20999.
Growing evidence has revealed that circular RNAs (circRNAs) play important roles in the development of cancers, including colorectal cancer (CRC). In this study, we mainly focused on the expression of circ_0056618 and potential functions of circ_0056618 in CRC patients.
RT-PCR was performed to detect circ_0056618 and miR-206 expressions in CRC tissues and adjacent non-tumor tissues. Correlation analysis was used to analyze the correlation between circ_0056618 and miR-206. Kaplan-Meier method was conducted to analyze the overall survival (OS) for CRC patients. Moreover, CCK-8 assay was used to measure cell proliferation ability and transwell assay was performed to detect cell migration ability. Besides, tube formation assay was performed to measure cell angiogenesis capacity. Western blot (WB) was performed to measure protein levels of tissues samples and CRC cell lines. Notably, the Luciferase reporter assay was performed to prove the binding sites in circ_0056618 with miR-206, miR-206 with CXCR4 and VEGF-A.
We found that circ_0056618 was elevated in CRC tumor tissues and CRC cell lines, which was related to poor diagnosis for CRC patients. MiR-206 was reduced in CRC tissues, which was negatively related with circ_0056618. Protein levels of CXCR4 and VEGF-A were elevated in CRC tumor tissues, which were negatively related with miR-206. Circ_0056618 inhibition inhibited proliferation, angiogenesis and migration of HT29 cells, and repressed protein levels of Cyclin D1, VEGF-A and N-cadherin and increased E-cadherin. Notably, Luciferase reporter assay indicated that circ_0056618 could sponge with miR-206, which could directly target at CXCR4 and VEGF-A. Finally, we proved a pathway that circ_0056618 promoted cell proliferation, migration and angiogenesis through sponging with miR-206 and removing the repressing effects of miR-206, thereby upregulating CXCR4 and VEGF-A in CRC.
Above all, this study revealed that circ_0056618 was increased in CRC tissues, which was related with the poor OS of CRC patients. We found that circ_0056618 could promote cell proliferation, migration and angiogenesis through sponging with miR-206 and upregulating CXCR4 and VEGF-A in CRC, which might provide a novel potential therapeutic target for treating CRC.
越来越多的证据表明，环状 RNA（circRNA）在癌症的发展中发挥着重要作用，包括结直肠癌（CRC）。在本研究中，我们主要关注 circ_0056618 的表达及其在 CRC 患者中的潜在功能。
采用 RT-PCR 检测 CRC 组织及相邻非肿瘤组织中 circ_0056618 和 miR-206 的表达。采用相关性分析分析 circ_0056618 与 miR-206 的相关性。采用 Kaplan-Meier 法分析 CRC 患者的总生存期（OS）。此外，采用 CCK-8 检测细胞增殖能力，Transwell 检测细胞迁移能力，管形成实验检测细胞血管生成能力。采用 Western blot（WB）检测组织样本和 CRC 细胞系中的蛋白水平。值得注意的是，通过荧光素酶报告实验证实了 circ_0056618 与 miR-206、miR-206 与 CXCR4 和 VEGF-A 之间的结合位点。
我们发现 circ_0056618 在 CRC 肿瘤组织和 CRC 细胞系中升高，与 CRC 患者的不良诊断有关。CRC 组织中 miR-206 降低，与 circ_0056618 呈负相关。CRC 肿瘤组织中 CXCR4 和 VEGF-A 蛋白水平升高，与 miR-206 呈负相关。抑制 circ_0056618 可抑制 HT29 细胞的增殖、血管生成和迁移，并抑制 Cyclin D1、VEGF-A 和 N-cadherin 的蛋白水平，增加 E-cadherin 的蛋白水平。值得注意的是，荧光素酶报告实验表明 circ_0056618 可以与 miR-206 结合，直接靶向 CXCR4 和 VEGF-A。最后，我们证明了一条通路，即 circ_0056618 通过与 miR-206 结合并去除 miR-206 的抑制作用，从而上调 CRC 中的 CXCR4 和 VEGF-A，促进细胞增殖、迁移和血管生成。
综上所述，本研究表明 circ_0056618 在 CRC 组织中升高，与 CRC 患者的不良 OS 相关。我们发现 circ_0056618 通过与 miR-206 结合并上调 CRC 中的 CXCR4 和 VEGF-A 来促进细胞增殖、迁移和血管生成，这可能为治疗 CRC 提供一个新的潜在治疗靶点。
