Expression Of 5-lipoxygenase In Human Gliomas And The Relationship Of 5-lipoxygenase On The Proliferation And Apoptosis Of Glioma Cells

Object: This study investigated the relationship of 5-lipoxygenase(5-LOX) on the proliferation of glioma cells by analysising the significance of 5-LOX and Ki-67 expression in glioma tissuses, discussed the effect and mechanisms of AA861 on the proliferation and apoptosis of glioma cells and provided the theoretical foundation for the new glioma treatment target for 5-LOX.Method: 60 cases of glioma specimen were divided into low potential malignancy glioma group(gradⅠ- gradⅡ, WHO 2000)and high potential malignancy glioma group(gradⅢ- gradⅣ, WHO 2000),14 cases of brain tissue induced by cerebral trauma was the control group. The expression of 5-LOX and Ki-67 were detected three groups by immunohistochemistry and RT-PCR.The glioma U-251 cells were cultivanted in DMEM culture solution that contain AA861.Morphological changes was observed under invert phase-contrast microscopy and transmission electron microscope.Drew the cel1 growth curve.Detecting the effect of AA861 different concentrations and different action times on the growth of glioma cells U-251 by MMT analysis. The rates of Cel1 apoptosis were evaluated by AO/EB fluorescein stain.Detecting the changes of caspase-3 activity in glioma U-251 cells by caspase-3 activity assay kit after the cells were interfered in different concentrations and different action times.Results:1 The expression of 5-LOX protein have been detected in control group and other human glioma groups(P<0.01). The expression level of 5-LOX protein in high potential malignancy glioma was considerably higher than those in low potential malignancy glioma (P<0.01). The expression of Ki-67 protein have been detected in control group and other human glioma groups(P<0.01). The expression level of Ki-67 protein in high potential malignancy glioma was considerably higher than those in low potential malignancy glioma (P<0.01).Moreover,there was a positive correlation between 5-LOX protein and Ki-67 protein expressions in human gliomas(γ=0.875,P<0. 01).2 The expression of 5-LOX mRNA have been detected in control group and other human glioma groups(P<0.01). The expression level of 5-LOX mRNA in high potential malignancy glioma was considerably higher than those in low potential malignancy glioma(P<0.05). The expression of Ki-67 mRNA have been detected in control group and other human glioma groups(P<0.01). The expression level of Ki-67 mRNA in high potential malignancy glioma was considerably higher than those in low potential malignancy glioma (P<0.01).Moreover,there was a positive correlation between 5-LOX mRNA and Ki-67 mRNA expressions in human gliomas(γ=0.781,P<0.01).3 Under the invert phase-contrast and scanning electronmicroscopy,AA861 induced apoptotic morphologic changes of U251.4 The cel1 growth curve and MTT assay revealed that different concentrations of AA861 inhibited the growth of U251 cells in a time-and dose-dependent manner. 5 The AO/EB fluorescein stain showed AA861 induce apoptosis in a time-and dose-dependent manner.6 Caspase-3 activity assay showed the score of A405nm was significantly higher in 25,50 and 100μmol/L groups than in control.In the same time, the A405nm scores were different in various AA861 concentration groups(P<0.05),the A405nm score increased with the increasing concentration. In the same concentration, the A405nm scores were different in various time(P<0.05), the A405nm score increased with the increasing action time.Conclusion:1 The expression of 5-LOX and Ki-67 have been detected in human gliomas and control group. The expression of 5-LOX and Ki-67 may be correlation to the pathological grades of human gliomas. Moreover,both 5-LOX and Ki-67 may be invoived in the tumorigenesis and progression in human gliomas.2 The inhibitor of 5-LOX can inhibit the glioma cell proliferation,it indicate 5-LOX may promote the proliferation of glioma cells.3 The inhibitor of 5-LOX can activate Caspase-3,induce glioma cell apoptosis, it indicate 5-LOX participate in the apoptosis of glioma cells.