Department of Obstetrics and Gynecology, Affiliated Jiangyin Hospital of South-East University, Jiangyin, 214400, China.
Department of Oncology, Affiliated Jiangyin Hospital of South-East University, Jiangyin, 214400, China.
Biochem Biophys Res Commun. 2018 Oct 20;505(1):309-316. doi: 10.1016/j.bbrc.2018.09.102. Epub 2018 Sep 21.
NK cells are presented in tumor microenvironments and acts as an essential defense line against multiple malignancies. Recently, miRNAs are reported to involve in the development of natural killer (NK) cells via negatively regulating gene expression. Here, we aim to explore the function and mechanism underlying how miR-20a modulated the killing effect of NK cells to cervical cancer cells.
Abundances of miR-20a and runt-related transcription factor 1 (RUNX1) in NK cells from cervical cancer patients and healthy donors were detected by qRT-PCR and western blot. The releases of IFN-γ and TNF-α were determined by ELISA. The cytotoxicity of NK cells against cervical cancer cells was measured by CytoTox 96 non-radioactive cytotoxicity assay. Luciferase reporter, western blot, and RNA immunoprecipitation (RIP) assays were performed to assess the interaction between miR-20a and RUNX1.
miR-20a was upregulated while RUNX1 was downregulated in NK cells from cervical cancer patients compared to healthy donors. IL-2 stimulated the releases of IFN-γ and TNF-α, and the killing effect of NK cells to cervical cancer cells, which was overturned by miR-20a introduction. RUNX1 was identified to be a target of miR-20a. Restoration of RUNX1 abolished the inhibitory effects of miR-20a on the secretions of IFN-γ and TNF-α, as well as the killing effect of NK cells to colorectal cancer cells.
miR-20a attenuated the killing effect of NK cells to cervical cancer cells by directly targeting RUNX1.
NK 细胞存在于肿瘤微环境中，是抵抗多种恶性肿瘤的重要防线。最近有研究报道，miRNA 通过负向调控基因表达参与自然杀伤（NK）细胞的发育。本研究旨在探讨 miR-20a 调节 NK 细胞杀伤宫颈癌细胞的作用及其机制。
采用 qRT-PCR 和 Western blot 检测宫颈癌患者和健康供者 NK 细胞中 miR-20a 和 runt 相关转录因子 1（RUNX1）的含量。ELISA 法检测 IFN-γ 和 TNF-α 的释放。采用 CytoTox 96 非放射性细胞毒性测定法检测 NK 细胞对宫颈癌细胞的细胞毒性。采用荧光素酶报告、Western blot 和 RNA 免疫沉淀（RIP）实验评估 miR-20a 与 RUNX1 之间的相互作用。
与健康供者相比，宫颈癌患者 NK 细胞中 miR-20a 上调而 RUNX1 下调。IL-2 刺激 IFN-γ 和 TNF-α的释放，并增强 NK 细胞对宫颈癌细胞的杀伤作用，而 miR-20a 的引入则逆转了这一作用。RUNX1 被鉴定为 miR-20a 的靶基因。RUNX1 的恢复消除了 miR-20a 对 IFN-γ 和 TNF-α 分泌以及 NK 细胞杀伤结直肠癌细胞的抑制作用。
miR-20a 通过直接靶向 RUNX1 减弱 NK 细胞对宫颈癌细胞的杀伤作用。
