背景:双特异性磷酸酶6(DUSP6)是丝裂原活化蛋白(MAP)激酶超家族的负反馈机制(MAPK/ERK,SAPK/JNK,p38),这与细胞增殖和分化有关。据报道,DUSP6在不同类型的乳腺癌中的表达是多样的,因此其在各种类型的乳腺癌中具有改变的功能。我们的目的是探索DUSP6在三阴性乳腺癌细胞(MDA-MB-231细胞)中的确切功能,并确定小干扰RNA(siRNA)和mircroRNA(miRNA)对DUSP6的抑制是否会抑制人MDA-MB-231乳腺癌细胞的生长。
方法:用DUSP6-siRNA直接抑制MDA-MB-231乳腺癌细胞中DUSP6的表达,用miR-145抑制DUSP6的表达,并通过Real-timePCR和WesternBlotting证实转染成功。如通过MTT测定和集落形式测定所研究的,MDA-MB-231细胞中DUSP6的下调抑制了细胞增殖。进行Transwell试验和划痕试验以研究MDA-MB-231细胞的迁移和侵袭。T检验(双尾)用于比较组间差异,显著性水平为P<0.05。
结果:直接转染DUSP6-siRNA后,DUSP6mRNA表达和蛋白表达降低,与转染miR-145的趋势相似。DUSP6-siRNA或miR-145治疗组抑制MDA-MB-231细胞增殖,移民和入侵,同时细胞被阻滞在G0/G1期。
结论:DUSP6在三阴性乳腺癌细胞中发挥作用,可能促进MDA-MB-231三阴性乳腺癌细胞的生长。
BACKGROUND: Dual-specificity phosphatase 6 (DUSP6) is a negative feedback mechanism of the mitogen-activated protein (MAP) kinase superfamily (MAPK/ERK, SAPK/JNK, p38), that is associated with cellular proliferation and differentiation. It has been reported that the expression of DUSP6 in different types of breast cancer is diverse and therefore it has altered functions in various types of breast cancer. Our aim was to explore the exact function of DUSP6 in triple-negative breast cancer cells (MDA-MB-231 cell) and to determine whether the suppression of DUSP6 by small interfering RNA (siRNA) and mircroRNA (miRNA) inhibits the growth of human MDA-MB-231 breast cancer cells.
METHODS: DUSP6-siRNA was used to inhibit the expression of DUSP6 directly and miR-145 to inhibit the expression of DUSP6 either in MDA-MB-231 breast cancer cells and successful transfection being confirmed by Real-time PCR and Western Blotting. Down regulation of DUSP6 in MDA-MB-231 cells suppressed the cell proliferation as investigated by MTT assay and colony form assay. Transwell test and Scratch assay were conducted to investigate the migration and invasion of MDA-MB-231 cells. T-test (two-tailed) was used to compare differences between groups, and the significance level was set at P<0.05.
RESULTS: DUSP6 mRNA expression and protein expression were reduced after transfection with DUSP6-siRNA directly and similar trend with transfection with miR-145. The treated group with DUSP6-siRNA or miR-145 suppressed MDA-MB-231 cells proliferation, migration and invasion, and meanwhile the cells were arrested at G0/G1 phase.
CONCLUSIONS: DUSP6 plays a role in triple-negative breast cancer cells that might promote growth in MDA-MB-231 triple-negative breast cancer cells.