Our data suggest that miR-21 contributes to glioma malignancy by downregulation of MMP inhibitors, which leads to activation of MMPs, thus promoting invasiveness of cancer cells.
MicroRNA-21 (miR-21) is the most consistently overexpressed miRNA in several cancers including gliomas and is therefore very promising as a useful clinical biomarker and therapeutic target.
We decided to investigate the expression of the oncogenic miR-21 during normal mouse development and glioma, focusing on PDGF signaling as a potential regulator of miR-21.
miR-21 may regulate the proliferation and apoptosis of human glioma cells by downregulating the expression of the PTEN protein, and miR-21 may represent a potential therapeutic target for the treatment of glioma.
These findings suggest that miR-21 is linked to glioma angiogenesis, that miR-21 is unlikely to regulate PTEN, and that miR-21-positive tumor cells do not possess stem cell characteristics.
These data provide compelling evidence that β-catenin regulation of miR-21 via STAT3 plays a role in glioma cell invasion and proliferation and indicate that STAT3 is a potential therapeutic target for glioma intervention.
Human glioma U87 cells were assigned into the blank, negative control (NC), miR-21 mimics, miR-21 inhibitors, siRNA-SPRY1, and miR-21 inhibitors + siRNA-SPRY1 groups, with human HEB cells serving as the normal group.
Several miRNAs have been recently reported to be involved in modulation of glioma development, especially some upregulated miRNAs, such as microRNA-21 (miR-21), which has been found to function as an oncogene in cultured glioblastoma multiforme cells.
Our results support a direct contribution of miRNAs to glioma cancerogenesis and suggest that miR-21 and miR-210 may play a role in the aggressive clinical behaviour of glioblastomas.
We found that the aberrant expression of miR-21 is responsible for glioma invasion by disrupting the negative feedback circuit of Ras/MAPK signaling, which is mediated by Spry2.
Hazard ratios (HRs) with 95 % confidence intervals (CIs) for overall survival (OS), which compared the expression levels of miRNA-21 in patients with gliomas, were extracted and estimated.
Several miRNAs have been recently reported to be involved in modulation of glioma development, especially some up-regulated miRNAs, such as microRNA-21 (miR-21), which has been found to function as an oncogene in cultured glioblastoma multiforme cells.
Our data suggest that miR-21 contributes to glioma malignancy by downregulation of MMP inhibitors, which leads to activation of MMPs, thus promoting invasiveness of cancer cells.
In this study, we showed that down-regulation of miR-21 expression by antisense oligonucleotides inhibited glioma cell proliferation and induced cell apoptosis.
Specific knockdown of DDX23 expression suppressed glioma cell proliferation and invasion in vitro and in vivo, which is similar to the function of miR-21.