ABSTRACT
Objective:To explore the mechanism of miR-205-5p/E2F1 signal axis in regulating the glioma U251, U87 radiotherapy resistance.Methods:X-ray gradual ascending and intermittent induction method was used to irradiate the glioma U251 cells to establish U251/TR, U87/TR radiation-resistant cell lines. Then, the morphology, migration, invasion and proliferation abilities of cells (U251/TR, U87/TR radiation-resistant cells and U251, U87 radiation-sensitive cells) were analyzed. Luciferase gene detection system and point mutation technique were employed to analyze the mechanism of miR-205-5p and E2F1 gene activity on U251 and U87 radiation-resistant cell lines.Results:Compared with the radiation-sensitive U251 cells, the radiation-resistant cells U251/TR, U87/TR showed increased proliferation activity, enhanced migration and invasion abilities and decreased apoptosis under X-ray irradiation. miR-205-5p mimics transfection could down-regulate the expression of E2F1 factor in U251/TR cells, inhibit cell proliferation, invasion and migration and increase the radiosensitivity of U251/TR cells. miR-205-5p mimics transfection combined with with E2F1 down-regulation exerted anti-tumor effect and decreased cell tolerance by suppressing the Wnt/β-catenin signaling pathway activity.Conclusions:The glioma radiation-resistant cell line U251/TR, U87/TR can be established by X-ray gradual ascending and intermittent induction method. The miR-205-5p/E2F1 signal axis exerts tumor-suppressing effect through the classical Wnt/β-catenin signaling pathway, which can be used as an therapeutic target to increase the radiosensitivity of glioma.
ABSTRACT
Objective To explore the role and expression of cell apoptosis regulatory genes in patients with temporal lobe epilepsy characterized by hippocampus sclerosis.Methods The experimental specimens were obtained from 15 patients with temporal lobe epilepsy (epilepsy group) and 6 control samples (control group) were obtained from temporal lobe excision of brain trauma decompression,investigated neuron apoptosis by HE stain,TdT-mediated dUTP-biotin nick end labeling (TUNEL) method,and determined the expression of bcl-2,bax and caspase-3 by immunohistochemistry.Results The evidence of neuron apoptosis was not found by HE stain in both control group and epilepsy group.Positive cells was not found in control group,but was obviously observed in epilepsy group by TUNEL staining [(4.39 ± 2.04) numbers/100].Unlike that in normal adult brain,bcl-2 immunoreactivity was obviously observed in some neurons in epilepsy group[(6.72 ± 3.36) numbers/100] (P ＜ 0.01).Compared with control group,bax protein in epilepsy group was mild expression (P ＞ 0.05).Two cases in control group were detected the expression of caspase-3 protein,and caspase-3 significantly increased in epilepsy group [(1.07 ± 0.43),(9.54 ± 3.68) numbers/100] (P ＜ 0.01).Conclusions Neuron apoptosis is an important cause of hippocampal sclerosis of human epilepsy.bcl-2 and caspase-3 may play an important role in this process.