RESUMO
<p><b>OBJECTIVE</b>To investigate the effect of micro RNA-21 (miRNA-21) knocking on the Tb3.1 human tongue squamous cell carcinoma growth.</p><p><b>METHODS</b>Anti-sense miRNA-21 oligonucleotide was delivered with oligofectamine to suppress Tb 3.1 tongue cancer cell growth in vitro. Real-time polymerase chain reaction (PCR) was conducted to detect the miRNA-21 expression after transfection. Methyl thiazolyl tetrazolium (MTT) assay was used to determine Tb 3.1 cell survival rate. Apoptosis were examined by flow-cytometry. Matrigel matrix and transwell assay were used to determine Tb 3.1 cell colony formation and migration ability. Antigen KI-67 (Ki67), B cell lymphoma (Bcl-2), phosphatase and tensin homolog (PTEN), matrirx metalloproteinase 2 (MMP-2, MMP-9) and tissue inhibitor of metalloproteinase 1 (TIMP-1) protein expression in Tb 3.1 cell were measured by Western blotting.</p><p><b>RESULTS</b>miRNA-21 expression was decreased in miRNA-21 antisense oligonucleotide (ASODN) group. The survival rate of Tb 3.1 cells with AS-miRNA-21 transfection was significantly suppressed (F = 27.02, P = 0.00) and early phase apoptosis (F = 26.641, P = 0.001) induced in Tb 3.1 cell. Ki67, Bcl-2, MMP-2 and MMP-9 protein were down regulated while PTEN and TIMP-1 protein expression was increased.</p><p><b>CONCLUSIONS</b>Blocking miRNA-21 expression in Tb3.1 cell could suppress cancer cell growth in vitro and miRNA-21 can serve as a novel target candidate for human tongue cancer gene therapy.</p>