RESUMO
Objective:To evaluate the effect of down-regulating lncRNA LINC00263 targeting miR-4458 on the proliferation, migration, invasion and radiosensitivity of breast cancer SK-BR-3 cells.Methods:The expression differences of LINC00263 in breast cancer tissues, adjacent tissues, normal breast epithelial cells and breast cancer cells were determined by qRT-PCR. Transfection of LINC00263 shRNA in breast cancer SK-BR-3 cells down-regulated the expression of LINC00263, and the cloning experiment was used to detect the radiosensitivity. Breast cancer SK-BR-3 cells were treated with 6 Gy irradiation. CCK-8 assay was employed to detect cell proliferation. Flow cytometry was adopted to detect cell apoptosis. Transwell chamber test was performed to detect cell migration and invasion. Western blot was used to detect the expression levels of C-Caspase-3 and C-Caspase-9, MMP-2 and MMP-9 proteins. Bioinformatics software predicted that LINC00263 and miR-4458 had complementary binding sites, and the luciferase reporter system was utilized determine the targeting relationship between LINC00263 and miR-4458. LINC00263 shRNA and miR-4458 inhibitor were co-transfected into breast cancer SK-BR-3 cells, and 6 Gy irradiation was given to detect the changes in cell proliferation, apoptosis, invasion and migration.Results:The expression level of LINC00263 in breast cancer tissues was higher than that in adjacent tissues. The expression level of LINC00263 in breast cancer cells was higher compared with that in normal breast epithelial cells. The radiosensitivity of breast cancer SK-BR-3 cells was increased after transfection of LINC00263 shRNA. Transfection of LINC00263 shRNA and radiation exerted a synergistic effect, jointly inhibited breast cancer cell proliferation, migration and invasion, promoted cell apoptosis, up-regulated the expression levels of C-Caspase-3 and C-Caspase-9 proteins in cells, and down-regulated those of MMP-2 and MMP-9 proteins. Down-regulation of LINC00263 targetedly up-regulated miR-4458 expression. miR-4458 inhibitor reversed the inhibitory effect of LINC00263 shRNA combined with radiation on the proliferation, migration, invasion and apoptosis promotion of breast cancer SK-BR-3 cells.Conclusion:Down-regulating lncRNA LINC00263 targeting miR-4458 inhibits the proliferation, migration and invasion of breast cancer SK-BR-3 cells, and improves cell radiosensitivity.
RESUMO
Objective:Through TTC staining, immunohistochemical analysis, RT-PCR and hind limb motor function evaluation and other experimental methods, to explore the regulatory mechanism of metformin on anti-apoptosis in rats with spinal cord injury (SCI).Methods:Establish a rat spinal cord injury model. Through Basso-Beattie -Bresnahan locomotor rating scale (BBB) and cant test to evaluate the recovery of hindlimb motor function in rats. The changes of necrotic area of spinal cord tissue were compared by TTC staining. Extraction of rat spinal cord tissue, by Dot blot analysis and immunohistochemical detection of the hydroxyl of DNA methylation level. By qPCR, Western Blot detection TET2mRNA and protein expression level, and the changes in the scope of spinal cord injury were detected by inhibiting the expression of TET2. The interaction between TET2 and Foxo3a was detected by immunoblotting and immunoprecipitation. Through RT-PCR assay Foxo3a downstream related changes in the level of gene expression.Results:Compared with the SCI+NS group, the necrotic area of the spinal cord tissue was reduced after metformin treatment, and the BBB score and the incline test score were higher ( P<0.05). At the same time, we found that the levels of TET2mRNA and protein increased significantly after SCI at 24 h, and the 5-hmC level of DNA increased. The levels of TET2mRNA and protein and 5-hmC increased further after the use of metformin. After using SC-1, compared with the SCI+MET group, the level of 5-hmC decreased and the area of infarction increased. After SCI, the mRNA levels of downstream genes Bim, P27kip, Bax increased significantly. After metformin treatment, the mRNA levels of Bim and Bax were lower than those in the SCI+NS group ( P<0.05). After SCI, the 5-hmC levels of downstream genes Bim, P27kip, Bax increased significantly. After metformin treatment, the 5-hmC levels of Bim and Bax were lower than those in the SCI+NS group ( P<0.05). Conclusion:Metformin can promote the interaction between TET2 and Foxo3a, increase the 5-hmC level of the overall DNA, and inhibit the activation of related apoptosis genes, thereby improving tissue damage and nerve function recovery after spinal cord injury.