环状RNA_PLEKHM3通过miR-320/KLF4轴调控宫颈癌细胞上皮间质转化

CircRNA_PLEKHM3 regulates epithelial mesenchymal transformation of cervical cancer cells through the miR-320/KLF4 axis

目的探讨环状RNA含普列克底物蛋白同源域的家族M3成员(PLEKHM3)(circRNA_PLEKHM3)通过调控微小RNA-320(miR-320)/畸变样因子4(KLF4)轴在宫颈癌细胞上皮间质转化(EMT)行为中的作用与机制。方法采用实时定量PCR(qRT-PCR)法检测宫颈癌细胞Hela和CaSki中circRNA_PLEKHM3的表达水平;RNA荧光原位杂交检测circRNA_PLEKHM3在人宫颈癌上皮细胞CaSki中的定位;双荧光素酶报告基因实验检测circRNA_PLEKHM3和miR-320的靶向关系,以及miR-320和KLF4的靶向关系;对CaSki细胞过表达circRNA_PLEKHM3;另外设置三组,分别为在过表达circRNA_PLEKHM3的基础上过表达miR-320、沉默KLF4,以及在过表达miR-320的基础上沉默KLF4。qRT-PCR检测CaSki中miR-320的表达水平;Western blot检测CaSki细胞中KLF4和EMT标志物上皮钙黏蛋白(E-cadherin)、神经钙黏蛋白(N-cadherin)、波形蛋白(Vimentin)、基质金属蛋白酶(MMP)-2和MMP-9的表达;Transwell实验检测细胞迁移数和侵袭细胞数。结果circRNA_PLEKHM3在Hela和CaSki中的表达均降低(P<0.05),其主要定位在细胞质中;双荧光素酶报告基因实验显示miR-320和circRNA_PLEKHM3存在靶向关系,KLF4和miR-320存在靶向关系;过表达circRNA_PLEKHM3抑制miR-320和N-cadherin、Vimentin、MMP-2、MMP-9的蛋白表达,上调E-cadherin的蛋白表达,减少细胞迁移和侵袭数(P<0.05);在过表达circRNA_PLEKHM3的基础上过表达miR-320或沉默KLF4均能够促进miR-320和N-cadherin、Vimentin、MMP-2、MMP-9蛋白的表达,上调E-cadherin蛋白的表达,减少迁移和侵袭细胞数(P<0.05);然而在过表达miR-320的基础上沉默KLF4,KLF4和N-cadherin、Vimentin、MMP-2、MMP-9蛋白的表达受到抑制,E-cadherin蛋白的表达上调,细胞迁移和侵袭数减少(P<0.05)。结论circRNA_PLEKHM3过表达可能通过miR-320/KLF4轴调控宫颈癌细胞的EMT。

Objective To investigate the role and mechanism of circular RNA containing pleckstrin homology domain of Pleckstrin homology domain family M member 3(circRNA_PLEKHM3)in regulating epithelial-mesenchymal transition(EMT)behavior in cervical cancer cells through the miR-320 and KLF4.Methods The expression levels of circRNA_PLEKHM3 in cervical cancer cells Hela and CaSki were detected by real-time quantitative PCR(qRT-PCR).RNA fluorescence in situ hybridization was used to determine the localization of circRNA_PLEKHM3 in human cervical cancer epithelial cells CaSki.Dual luciferase reporter gene experiments were conducted to investigate the targeting relationship between circRNA_PLEKHM3 and miR-320,as well as the targeting relationship between miR-320 and KLF4.CaSki cells were overexpressed with circRNA_PLEKHM3.Additionally,three groups were set up:overexpression of miR-320 on the basis of circRNA_PLEKHM3 overexpression,silencing of KLF4 on the basis of circRNA_PLEKHM3 overexpression,and silencing of KLF4 on the basis of miR-320 overexpression.qRT-PCR was performed to detect the expression levels of miR-320 in CaSki.Western blot experiments were conducted to determine the expression of KLF4 and EMT markers including E-cadherin,N-cadherin,Vimentin,MMP-2,and MMP-9 in CaSki cells.Transwell assays were performed to measure cell migration and invasion.Results The expression of circRNA_PLEKHM3 decreased in Hela and CaSki cells(P<0.05),mainly localized in the cytoplasm.The dual luciferase reporter gene experiment demonstrated a targeting relationship between miR-320 and circRNA_PLEKHM3,as well as between KLF4 and miR-320.Overexpression of circRNA_PLEKHM3 inhibited the protein expression of miR-320,N-cadherin,Vimentin,MMP-2,and MMP-9,up-regulated the protein expression of E-cadherin,and reduced cell migration and invasion(P<0.05).Overexpression of miR-320 or silencing of KLF4 on the basis of circRNA_PLEKHM3 overexpression both promoted the protein expression of miR-320,N-cadherin,Vimentin,MMP-2,and MMP-9,down-regulated the protein expression of E-cadherin,and increased cell migration and invasion(P<0.05).However,silencing of KLF4 on the basis of miR-320 overexpression inhibited the protein expression of KLF4,N-cadherin,Vimentin,MMP-2,and MMP-9,up-regulated the protein expression of E-cadherin,and reduced cell migration and invasion(P<0.05).Conclusion Overexpression of circRNA_PLEKHM3 regulates EMT in cervical cancer cells through the miR-320/KLF4 axis.