Co-inhibition of miRNA-21 and miRNA-221 induces apoptosis by enhancing the p53-mediated expression of pro-apoptotic miRNAs in laryngeal squamous cell carcinoma
Co-inhibition of miRNA-21 and miRNA-221 induces apoptosis by enhancing the p53-mediated expression of pro-apoptotic miRNAs in laryngeal squamous cell carcinoma
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DOI：
10.3892/mmr.2016.5048
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发表时间：
2016-05-01
影响因子：
3.4
通讯作者：
Tian, Linli
中科院分区：
文献类型：
--
作者：
Kan, Xuan;Sun, Yanan;Tian, Linli
许多microRNAs（miRNAs）的失调与喉鳞状细胞癌（LSCC）有关。在这些miRNA中，miR-21和miR-221共过表达，并且通常靶向位于PTEN-Akt信号通路中的磷酸酶和张力蛋白同源蛋白（PTEN）。本研究探讨miR-21和miR-221的共抑制是否诱导人喉鳞癌细胞的协同凋亡。采用MTT法和末端脱氧核苷酸转移酶介导的三磷酸脱氧核苷酸缺口末端标记法（TUNEL）观察miR-21和miR-221对AMO-21和AMO-221共转染细胞活力和凋亡的影响。Western blotting检测PTEN、Akt和p53蛋白表达水平。采用逆转录-定量聚合酶链反应（RT-qPCR）检测p53介导的6种促凋亡miRNA（miR-15 a、miR-16-1、miR-26 a、miR-34 a、miR-143和miR-203）的细胞丰度。MTT结果表明，与单独转染AMO相比，体外AMO-21和AMO-221共转染导致细胞活力下降。这一结果通过使用TUNEL分析检测细胞凋亡来验证。AMO-21和AMO-221的共转染导致Akt磷酸化的显著降低，并且观察到PTEN和p53的表达增强;因此，导致6种促凋亡miRNA的转录扩增。本研究结果证实，miR-21和miR-221的共抑制在体外协同触发细胞凋亡。改变的PTEN-Akt信号传导和p53介导的促凋亡miRNA转录的扩增可能参与观察到的协同效应。本研究为喉鳞状细胞癌中细胞凋亡相关的miRNA-miRNA相互调节机制提供了新的见解。
Dysregulation of a numerous microRNAs (miRNAs) has been implicated in laryngeal squamous cell carcinoma (LSCC). Among those miRNAs, miR-21 and miR-221 are co-overexpressed and commonly target the phosphatase and tensin homolog protein (PTEN) that is located in the PTEN-Akt signaling pathway. The present study investigated whether co-inhibition of miR-21 and miR-221 induced synergistic apoptosis of human LSCC cells. Methyl thiazolyl tetrazolium (MTT) and terminal deoxynucleotidyl-transferase-mediated deoxynucleotide triphosphate nick end labeling (TUNEL) assays were used to observe the potential effect of miR-21 and miR-221 on cell viability and apoptosis in cells co-transfected with anti-miRNA oligonucleotide (AMO)-21 and AMO-221. The protein expression levels of PTEN, Akt and p53 were determined by western blotting. The cellular abundance of 6 pro-apoptotic miRNAs transcribed by p53 mediation, consisting of miR-15a, miR-16-1, miR-26a, miR-34a, miR-143 and miR-203, was measured with using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). MTT results indicate that in vitro co-transfection of AMO-21 and AMO-221 leads to a decline in cell viability, compared with the transfection of AMO alone. This result was verified by the detection of apoptosis using TUNEL assays. Co-transfection of AMO-21 and AMO-221 resulted in a marked reduction in Akt phosphorylation and enhanced expression of PTEN and p53 were observed; consequently, leading to an amplification of the transcription of 6 pro-apoptotic miRNAs. The present findings confirmed that co-inhibition of miR-21 and miR-221 synergistically triggers cell apoptosis in vitro. The altered PTEN-Akt signaling and p53-mediated amplification of the transcription of pro-apoptotic miRNAs may be involved in the observed synergistic effect. The present study provides novel insights into the mechanism underlying apoptosis-associated miRNA-miRNA mutual regulation in LSCC.