miR-300 regulates cellular radiosensitivity through targeting p53 and apaf1 in human lung cancer cells
miR-300 regulates cellular radiosensitivity through targeting p53 and apaf1 in human lung cancer cells
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miR-300通过靶向人肺癌细胞中的p53和apaf1来调节细胞放射敏感性
DOI：
10.1080/15384101.2017.1367070
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发表时间：
2017-01-01
期刊：
影响因子：
4.3
通讯作者：
Wang, Jufang
中科院分区：
文献类型：
--
作者：
He, Jinpeng;Feng, Xiu;Wang, Jufang
摘要microRNAs(MiRNAs)在调节细胞对电离辐射(IR)的敏感性中起着至关重要的作用。以往的研究表明miR-300参与了细胞对IR或化疗药物的反应。然而，miR-300是否能调节外源性遗传毒性应激诱导的人肺癌DNA损伤反应及其机制尚不清楚。本研究检测了IR对肺癌细胞miR-300表达的影响，探讨了miR-300对IR诱导的肺癌细胞DNA损伤修复、细胞周期停滞、细胞凋亡和衰老的影响。结果发现，IR诱导内源性miR-300表达上调，并通过转染miR-300模拟物异位表达miR-300，不仅大大增强了细胞的DNA损伤修复能力，而且显著地取消了IR诱导的G2细胞周期停滞和细胞凋亡。生物信息学分析表明，p53和apaf1是miR-300的潜在靶点，荧光素酶报告基因分析表明miR-300通过与p53或apaf1基因的3‘端非编码区结合，显著抑制了荧光素酶的活性。此外，miR-300过表达显著降低了P53/apaf1和/或IR诱导的P53/apaf1蛋白表达水平。流式细胞仪分析和集落形成实验表明，miR-300通过抑制P53依赖的G2细胞周期停滞、细胞凋亡和衰老来降低肺癌细胞对IR的敏感性。这些数据表明miR-300通过靶向肺癌细胞中的p53和apaf1来调节细胞对IR的敏感性。
ABSTRACT microRNAs (miRNAs) play a crucial role in mediation of the cellular sensitivity to ionizing radiation (IR). Previous studies revealed that miR-300 was involved in the cellular response to IR or chemotherapy drug. However, whether miR-300 could regulate the DNA damage responses induced by extrinsic genotoxic stress in human lung cancer and the underlying mechanism remain unknown. In this study, the expression of miR-300 was examined in lung cancer cells treated with IR, and the effects of miR-300 on DNA damage repair, cell cycle arrest, apoptosis and senescence induced by IR were investigated. It was found that IR induced upregulation of endogenous miR-300, and ectopic expression of miR-300 by transfected with miR-300 mimics not only greatly enhanced the cellular DNA damage repair ability but also substantially abrogated the G2 cell cycle arrest and apoptosis induced by IR. Bioinformatic analysis predicted that p53 and apaf1 were potential targets of miR-300, and the luciferase reporter assay showed that miR-300 significantly suppressed the luciferase activity through binding to the 3′-UTR of p53 or apaf1 mRNA. In addition, overexpression of miR-300 significantly reduced p53/apaf1 and/or IR-induced p53/apaf1 protein expression levels. Flow cytomertry analysis and colony formation assay showed that miR-300 desensitized lung cancer cells to IR by suppressing p53-dependent G2 cell cycle arrest, apoptosis and senescence. These data demonstrate that miR-300 regulates the cellular sensitivity to IR through targeting p53 and apaf1 in lung cancer cells.