人脑胶质瘤组织中锌指样转录因子4的表达及其对肿瘤细胞活性的影响

Expressions of krüppel-like factor 4 in human glioma tissues and its effect on activity of tumor cells

目的探讨人脑胶质瘤组织中锌指样转录因子4(KLF4)的表达及其对肿瘤细胞活性的影响。方法收集2018年3月至2019年5月河南省南阳市第二人民医院收治的74例初发恶性胶质瘤患者术中切除的胶质瘤组织标本,收集同期手术切除的50例良性脑膜瘤组织,以及31例因头部外伤手术切除的正常脑组织。实时荧光定量聚合酶链反应(RT-PCR)检测组织中KLF4 mRNA表达水平。选取脑胶质瘤U-87MG细胞,构建KLF4低表达脑胶质瘤细胞模型,分为空白对照组、KLF4-NC组、KLF4-siRNA组。MTS细胞增殖检测试剂盒检测细胞增殖能力,蛋白质印迹法检测E-钙黏蛋白、波形蛋白、紧密连接蛋白1(ZO-1)表达水平。结果低级别胶质瘤、良性脑膜瘤、正常脑组织中KLF4 mRNA相对表达量分别为0.26±0.04、0.13±0.02、0.11±0.02,均低于高级别胶质瘤的0.34±0.06,差异均有统计学意义(t值分别为8.381、15.720、15.984,均P<0.05);良性脑膜瘤、正常脑组织中KLF4 mRNA相对表达量低于低级别胶质瘤,差异均有统计学意义(t值分别为13.771、14.239,均P<0.05)。细胞培养各时间点,KLF4-siRNA组U-87MG细胞增殖能力均低于空白对照组和KLF4-NC组,差异均有统计学意义(均P<0.05);空白对照组与KLF4-NC组U-87MG细胞增殖能力之间差异无统计学意义(P>0.05)。KLF4-siRNA组E-钙黏蛋白、ZO-1蛋白相对表达量分别为0.82±0.10、0.79±0.11,均高于空白对照组的0.24±0.08、0.39±0.05和KLF4-NC组的0.26±0.05、0.42±0.09,差异均有统计学意义(均P<0.01);KLF4-siRNA组波形蛋白相对表达量为0.31±0.08,低于空白对照组的0.90±0.08和KLF4-NC组的0.92±0.05,差异均有统计学意义(均P<0.01);空白对照组与KLF4-NC组间E-钙黏蛋白、波形蛋白、ZO-1蛋白表达水平差异均无统计学意义(均P>0.05)。结论人脑胶质瘤组织,尤其高级别胶质瘤中KLF4表达水平升高。下调KLF4表达可能抑制胶质瘤细胞增殖和上皮间质转化的发生,降低细胞活性。

Objective To investigate the expressions of krüppel-like factor 4(KLF4)in human glioma tissues and its effect on the activity of tumor cells.Methods The glioma tissues specimens of 74 patients with primary malignant gliomas who were admitted to Nanyang Second General Hospital of Henan Province from March 2018 to May 2019 were collected.During the same period,50 cases of benign meningioma tissues and 31 cases of normal brain tissues receiving surgery because of head injury were also collected.Real-time fluorescence quantitative polymerase chain reaction(RT-PCR)was used to detect the expression of KLF4 mRNA in tissues.Glioma U-87MG cells were selected and the glioma cell models with low-expression of KLF4 were constructed and were divided into the blank control group,KLF4-NC group and KLF4-siRNA group.The proliferation ability of cells was detected by using MTS cell proliferation detection kit,and the expression levels of E-cadherin,vimentin and zonula occludens protein 1(ZO-1)were detected by using Western blot.Results The relative expression level of KLF4 mRNA in low-grade glioma,benign meningioma,and normal brain tissues was 0.26±0.04,0.13±0.02,0.11±0.02,respectively,which were lower than that in high-grade glioma(0.34±0.06),and the difference was statistically significant(t=8.381,15.720,15.984,all P<0.05).The relative expression level of KLF4 mRNA in benign meningiomas and normal brain tissues was lower than that in low-grade gliomas,and the difference was statistically significant(t=13.771,14.239,all P<0.05).At each time point of cell culture,the proliferation ability of U-87MG cells in KLF4-siRNA group was lower than that of the blank control group and KLF4-NC group,and the difference was statistically significant(all P<0.05).There was no significant difference in U-87MG cell proliferation ability between the blank control group and KLF4-NC group(P>0.05).The relative expression level of E-cadherin and ZO-1 protein in KLF4-siRNA group was 0.82±0.10,0.79±0.11,respectively,which were higher than that in the blank control group(0.24±0.08,0.39±0.05)and KLF4-NC group(0.26±0.05,0.42±0.09),and the difference was statistically significant(all P<0.01);and the relative expression level of vimentin in KLF4-siRNA group(0.31±0.08)was lower than that in the blank control group(0.90±0.08)and KLF4-NC group(0.92±0.05),and the difference was statistically significant(all P<0.01).There was no statistically significant difference in the expression level of E-cadherin,vimentin and ZO-1 between the blank control group and KLF4-NC group(all P>0.05).Conclusion The expression level of KLF4 is increased in human glioma tissues,especially in high-grade glioma.Down-regulating the expression of KLF4 may inhibit glioma cell proliferation and epithelial-mesenchymal transition,and reduce cell activity.