Department of Gastroenterology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.
Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.
Biomed Pharmacother. 2018 May;101:257-263. doi: 10.1016/j.biopha.2018.02.024. Epub 2018 Feb 27.
To identify the molecular mechanism that modulates the killing effect of natural killer (NK) cells to colorectal cancer cells.
Expressions of miR-24 and Paxillin were detected by qRT-PCR and Western blot. Secretions of IFN-γ and TNF-α were measured by ELISA. The killing effect of NK cells was detected by CytoTox 96 non-radioactive cytotoxicity assay. Luciferase reporter assay was conducted to confirm the regulation of miR-24 on Paxillin.
miR-24 was overexpressed in NK cells from patients with colorectal cancer than healthy volunteers. Secretions of IFN-γ and TNF-α in activated NK cells were significantly increased, indicating the enhancement of the killing effect of NK cells. Paxillin expression was overexpressed in activated NK cells. Interference of Paxillin significantly decreased Paxillin expression, secretions of IFN-γ and TNF-α, and the killing effect of NK cells to colorectal cancer cells. In addition, we confirmed that Paxillin was a direct target of miR-24, and miR-24 was negatively correlated with Paxillin. Moreover, overexpression of miR-24 inhibited secretions of IFN-γ and TNF-α, and decreased cytotoxicity by downregulating Paxillin expression. Finally, we observed that overexpression of Paxillin significantly decreased tumor volume of colorectal cancer.
Overexpression of miR-24 supressed the killing effect of NK cells to colorectal cancer cells by downregulating Paxillin expression.
鉴定调节自然杀伤 (NK) 细胞杀伤结直肠癌细胞效应的分子机制。
采用 qRT-PCR 和 Western blot 检测 miR-24 和桩蛋白的表达。采用 ELISA 检测 IFN-γ 和 TNF-α 的分泌。采用 CytoTox 96 非放射性细胞毒性测定法检测 NK 细胞的杀伤效应。通过荧光素酶报告实验证实 miR-24 对桩蛋白的调控作用。
与健康志愿者相比，结直肠癌患者 NK 细胞中 miR-24 呈过表达。激活的 NK 细胞中 IFN-γ 和 TNF-α 的分泌明显增加，表明 NK 细胞杀伤作用增强。激活的 NK 细胞中桩蛋白表达过表达。桩蛋白干扰显著降低了 Paxillin 的表达、IFN-γ 和 TNF-α 的分泌以及 NK 细胞对结直肠癌细胞的杀伤作用。此外，我们证实桩蛋白是 miR-24 的直接靶标，miR-24 与 Paxillin 呈负相关。此外，过表达 miR-24 通过下调 Paxillin 表达抑制 IFN-γ 和 TNF-α 的分泌，并降低细胞毒性。最后，我们观察到过表达桩蛋白可显著降低结直肠癌细胞的肿瘤体积。
miR-24 的过表达通过下调桩蛋白表达抑制 NK 细胞对结直肠癌细胞的杀伤作用。
