MicroRNAs (miRNA), a class of small noncoding RNAs, regulates message RNA (mRNA) 
by targeting the 3'-untranslated region (3'-UTR) resulting in suppression of 
gene expression. In this study, we identified the expression and function of 
miR-128, which was found to be downregulated in glioma tissues and glioma cells 
by real time PCR. Overexpression of miR-128 mimics into LN229 and U251 cells 
could inhibit proliferation and invasion of glioma cells. However, the 
inhibitory effects of miR-128 mimics on the invasion and proliferation of glioma 
cells were reversed by overexpression of cyclooxygenase-2 (COX-2). Our data 
showed that COX-2 was a candidate target of miR-128. Luciferase activity of 
3'-UTR of COX-2 was reduced in the presence of miR-128. Additionally, miR-128 
obviously decreased COX-2 mRNA stability determined by real time PCR. 
Contrarily, we found that miR-128 inhibitor significantly increased the COX-2 
mRNA expression, and elevated the protein expression of MMP9 and ki67, and 
promoted the proliferation of glioma cells. Furthermore, luciferase activity of 
the 3'-UTR was upregulated by miR-128 inhibitor. All of these results supported 
that miR-128 was a direct regulator of COX-2. Further studies proved that COX-2 
was elevated in glioma tissues and its expression was negatively correlated with 
the levels of miR-128. These findings may establish miR-128 as a new potential 
target for the treatment of patients with gliomas.