下调lncRNA LINC00263靶向miR-4458调控乳腺癌SK-BR-3细胞放射敏感性

目的 研究下调lncRNA LINC00263靶向miR-4458对乳腺癌SK-BR-3细胞增殖、运动、侵袭及放射敏感性影响。方法 qRT-PCR方法分别检测乳腺癌组织、癌旁组织、正常乳腺上皮细胞和乳腺癌细胞中LINC00263表达差异。SK-BR-3细胞中转染LINC00263shRNA下调LINC00263表达,克隆实验检测放射敏感性。SK-BR-3细胞给予6Gy照射处理,CCK-8检测细胞增殖,流式细胞术检测凋亡,Transwell小室检测细胞运动和侵袭,蛋白印迹法检测C-Caspase-3、C-Caspase-9、MMP-2、MMP-9蛋白表达。生物信息学软件预测LINC00263和miR-4458有互补结合位点,荧光素酶报告系统测定二者的靶向关系。在SK-BR-3细胞中共转染LINC00263shRNA和miR-4458 inhibitor,给予6Gy照射处理,检测细胞增殖、运动、侵袭和凋亡变化。结果 乳腺癌组织中LINC00263表达水平高于癌旁组织。乳腺癌细胞中LINC00263表达水平高于正常乳腺上皮细胞。转染LINC00263shRNA以后的SK-BR-3细胞放射敏感性增加。转染LINC00263shRNA和放射联合具有协同作用,共同抑制细胞增殖、运动、侵袭,促进细胞凋亡,提高细胞中C-Caspase-3、C-Caspase-9蛋白表达水平,降低细胞中MMP-2、MMP-9蛋白表达水平。下调LINC00263靶向促进miR-4458表达。miR-4458 inhibitor逆转LINC00263shRNA联合放射对SK-BR-3细胞增殖、运动、侵袭的抑制作用和凋亡促进作用。结论 下调lncRNA LINC00263靶向miR-4458抑制SK-BR-3细胞增殖、运动、侵袭,提高细胞放射敏感性。

Effect of down-regulation of lncRNA LINC00263 targeting miR-4458 on regulating radiosensitivity of breast cancer SK-BR-3 cells

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 LINC00263shRNA 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 6Gy 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-4458had complementary binding sites, and the luciferase reporter system was utilized determine the targeting relationship between LINC00263 and miR-4458. LINC00263shRNA and miR-4458 inhibitor were co-transfected into breast cancer SK-BR-3 cells, and 6Gy 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 LINC00263shRNA. Transfection of LINC00263shRNA 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 LINC00263shRNA 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.