目的研究骨形成蛋白4（bone morphogenetic protein 4，BMP4）对人胶质瘤干细胞增殖和凋亡的影响。方法在体外以重组人BMP4蛋白干预人胶质瘤U87细胞系来源的胶质瘤干细胞，免疫荧光鉴定胶质瘤干细胞，通过软琼脂克隆实验、流式细胞仪检测，观察BMP4对胶质瘤干细胞增殖和凋亡的影响。结果BMP4能显著抑制胶质瘤干细胞的增殖能力，并诱导其凋亡。BMP4组增殖相关蛋白Cyclin D1表达降低，抗凋亡蛋白Bcl-2表达明显降低，促凋亡蛋白Bax表达显著增多。结论BMP4可显著抑制胶质瘤U87细胞系来源的胶质瘤干细胞的增殖能力，并诱导其凋亡。
MicroRNAs regulate self renewal and differentiation of cancer stem cells.There,we sought to identify the expression of miR-181b in glioma stem cells and investigate the biological effect of miR-181b on glioma stem cells in this study.MiR-181b expression was measured by real-time PCR in glioma stem cells isolated from U87 cells by FACS sorting.After miR-181b was overexpressed in U87 glioma stem cells by miR-181b lentiviral expression vector and/or treatment of temozolomide,secondary neurosphere assay,soft agar colony assay and MTT assay were performed.Compared with U87 cells,the expression of miR-181b was significantly decreased in U87 glioma stem cells.Overexpression of miR-181b decreased neurosphere formation by U87 glioma stem cells in vitro and suppressed colony formation in soft agar,and the cell growth inhibition rates increased in a time-dependent manner in U87 glioma stem cells infected with miR-181b lentivirus.Furthermore,miR-181b had a synergistic effect on temozolomide-induced inhibition of secondary neurosphere and soft agar colony,and on cell growth inhibition rates.MiR-181b functions as a tumor suppressor that suppresses proliferation and reduces chemoresistance to temozolomide in glioma stem cells.
Ping LiXiaoming LuYingyi WangLihua SunChunfa QianWei YanNing LiuYongping YouZhen Fu
Background Invasion growth is the most characteristic biological phenotype of glioblastoma, but the molecular mechanism in glioma cell invasion is poorly understood. Recent data have showed that microRNA plays an essential role in tumor invasion. Our study aimed to explore the mechanism of miR-7 involved in the control of glioblastoma cell invasion. Methods Glioma cell invasion was evaluated by transwell and scratch assays after up-regulation of miR-7 using miR-7 mimics in U87 and U251 cells. Luciferase reporter assay was used to determine focal adhesion kinase （FAK） as a target of miR-7. The levels of miR-7, matrix metalloproteinases （MMP）-2 and MMP-9 mRNA were detected by PCR assay, and the levels of FAK, MMP-2, MMP-9, total and phosphorylation serine/threonine kinase （AKT）, and extracellular signal-regulated kinase （ERK） 1/2 were measured by Western blotting analysis. Results Over-expression of miR-7 inhibited the invasion and migration activity of U87 and U251 cells. And up-regulation of miR-7 reduced FAK protein expression, Further, luciferase reporter assay showed that miR-7 modulated FAK expression directly by binding 3＇UTR of FAK mRNA. In addition, miR-7 repressed p-ERK1/2 and p-AKT level, MMP-2 and MMP-9 expression. Finally, the inverse relationship between FAK and miR-7 expression was certificated in human glioma tissues. Conclusion To our knowledge, these data indicate for the first time that miR-7 directly regulates cell invasion by targeting FAK in glioblastoma and that miR-7 could be a potential therapeutic target for glioblastoma intervention.
WU De-gang WANG Ying-yi FAN Li-gang LUO Hui HAN Bin SUN Li-hua WANG Xie-feng ZHANG Jun-xia CAO Lei WANG Xi-rui YOU Yong-ping LIU Ning
