MicroRNAs （miRNAs）, which are small noncoding RNA molecules, play important roles in the post-transcriptional regulation process. The microRNA-21 gene （miR-21） has been reported to be highly expressed in various s...MicroRNAs （miRNAs）, which are small noncoding RNA molecules, play important roles in the post-transcriptional regulation process. The microRNA-21 gene （miR-21） has been reported to be highly expressed in various solid tumors, including breast cancer. Bone morphogenetic protein-6 （BMP-6） has been identified as an inhibitor of breast cancer epithelial-mesenchymal transition （EMT） through rescuing E-cadherin expression. We initiated experi- ments to identify the relationships between miR-21 and BMP-6 in breast cancer progression. Real-time PCR analysis showed that miR-21 expression was very high in MDA-MB-231 cells that expressed little BMP-6. A reverse correla- tion between BMP-6 and miR-21 was also determined in breast cancer tissue samples. Moreover, BMP-6 inhibited miR-21 transcription in MDA-MB-231 cells. In order to investigate how BMP-6 inhibited the miR-21 promoter （miPPR-21）, we constructed a series of miPPR-21 reporters. Luciferase assay results indicated that BMP-6 inhibited miPPR-21 activity through the E2-box and AP-l-binding sites. We also demonstrated that both δEF1 and TPA in- duced miR-21 expression. Using site-directed mutation and CHIP assay, we found that δEF1 induced miPPR-21 ac- tivity by binding to the E2-box on miPPR-21. Moreover, TPA triggered miPPR-21 activity through the AP-I binding sites. BMP-6 treatment significantly reduced the binding of these factors to miPPR-21 by decreasing the expression of δEF1 and c-Fos/c-Jun. We also demonstrated that BMP-6-induced downregulation of miR-21 modified the activ- ity of PDCD4 3＇UTR and inhibited MDA-MB-231 cell invasion. δEF1 overexpression and TPA induction blocked this inhibitory effect of BMP-6. In conclusion, BMP-6-induced inhibition of miR-21 suggests that BMP-6 may function as an anti-metastasis factor by a mechanism involving transcriptional repression of miR-21 in breast cancer.展开更多
目的:观察电针(EA)治疗兔膝骨关节炎(KOA)模型关节软骨中骨形态发生蛋白-2(BMP-2)、Smad1表达的变化,探讨电针治疗KOA的作用机制。方法:制作兔膝关节炎模型,将建模成功的新西兰兔纳入模型对照组;正常组和模型组行常规饲养,不行治疗;电...目的:观察电针(EA)治疗兔膝骨关节炎(KOA)模型关节软骨中骨形态发生蛋白-2(BMP-2)、Smad1表达的变化,探讨电针治疗KOA的作用机制。方法:制作兔膝关节炎模型,将建模成功的新西兰兔纳入模型对照组;正常组和模型组行常规饲养,不行治疗;电针组行电针治疗20d。实验结束后,分别观察各组兔行为学评分、右膝关节宽度、软骨大体形态及组织学评分、软骨BMP-2、Smad1免疫组化及实时荧光定量PCR的变化。结果:电针组与模型组在行为学评分、软骨大体形态及组织学评分(Mankin评分)方面差异均无显著性(P>0.05),电针组兔右膝关节宽度小于模型组(P<0.05)。各组BMP-2免疫组化结果无显著差异,电针组较模型组Smad1蛋白质表达降低。模型组和模型对照组BMP-2 m RNA表达水平较正常组上调,差异无显著性意义(P>0.05),模型组Smad1m RNA表达水平较模型对照组和正常组均显著上调(P<0.05),电针组BMP-2及Smad1 m RNA表达水平较模型对照组和模型组均显著下调(P<0.05)。结论:电针可能通过下调早期兔膝骨关节炎软骨BMP-2/Smad1的表达抑制骨赘形成,延缓膝骨关节炎的病理进程。展开更多
文摘MicroRNAs （miRNAs）, which are small noncoding RNA molecules, play important roles in the post-transcriptional regulation process. The microRNA-21 gene （miR-21） has been reported to be highly expressed in various solid tumors, including breast cancer. Bone morphogenetic protein-6 （BMP-6） has been identified as an inhibitor of breast cancer epithelial-mesenchymal transition （EMT） through rescuing E-cadherin expression. We initiated experi- ments to identify the relationships between miR-21 and BMP-6 in breast cancer progression. Real-time PCR analysis showed that miR-21 expression was very high in MDA-MB-231 cells that expressed little BMP-6. A reverse correla- tion between BMP-6 and miR-21 was also determined in breast cancer tissue samples. Moreover, BMP-6 inhibited miR-21 transcription in MDA-MB-231 cells. In order to investigate how BMP-6 inhibited the miR-21 promoter （miPPR-21）, we constructed a series of miPPR-21 reporters. Luciferase assay results indicated that BMP-6 inhibited miPPR-21 activity through the E2-box and AP-l-binding sites. We also demonstrated that both δEF1 and TPA in- duced miR-21 expression. Using site-directed mutation and CHIP assay, we found that δEF1 induced miPPR-21 ac- tivity by binding to the E2-box on miPPR-21. Moreover, TPA triggered miPPR-21 activity through the AP-I binding sites. BMP-6 treatment significantly reduced the binding of these factors to miPPR-21 by decreasing the expression of δEF1 and c-Fos/c-Jun. We also demonstrated that BMP-6-induced downregulation of miR-21 modified the activ- ity of PDCD4 3＇UTR and inhibited MDA-MB-231 cell invasion. δEF1 overexpression and TPA induction blocked this inhibitory effect of BMP-6. In conclusion, BMP-6-induced inhibition of miR-21 suggests that BMP-6 may function as an anti-metastasis factor by a mechanism involving transcriptional repression of miR-21 in breast cancer.
文摘目的:观察电针(EA)治疗兔膝骨关节炎(KOA)模型关节软骨中骨形态发生蛋白-2(BMP-2)、Smad1表达的变化,探讨电针治疗KOA的作用机制。方法:制作兔膝关节炎模型,将建模成功的新西兰兔纳入模型对照组;正常组和模型组行常规饲养,不行治疗;电针组行电针治疗20d。实验结束后,分别观察各组兔行为学评分、右膝关节宽度、软骨大体形态及组织学评分、软骨BMP-2、Smad1免疫组化及实时荧光定量PCR的变化。结果:电针组与模型组在行为学评分、软骨大体形态及组织学评分(Mankin评分)方面差异均无显著性(P>0.05),电针组兔右膝关节宽度小于模型组(P<0.05)。各组BMP-2免疫组化结果无显著差异,电针组较模型组Smad1蛋白质表达降低。模型组和模型对照组BMP-2 m RNA表达水平较正常组上调,差异无显著性意义(P>0.05),模型组Smad1m RNA表达水平较模型对照组和正常组均显著上调(P<0.05),电针组BMP-2及Smad1 m RNA表达水平较模型对照组和模型组均显著下调(P<0.05)。结论:电针可能通过下调早期兔膝骨关节炎软骨BMP-2/Smad1的表达抑制骨赘形成,延缓膝骨关节炎的病理进程。
