Expressions of krüppel-like factor 4 in human glioma tissues and its effect on activity of tumor cells / 肿瘤研究与临床

ABSTRACT

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.