OBJECTIVETo study the role and possible mechanism of glioma-associated oncogene-1 (Gli1) in regulating the cell invasion and migration of pancreatic cancer cells.

METHODSQuantitative real-time (qRT) -PCR was used to detect the effect of siRNA interference on Gli1, murine double minute 2 (MDM2) and p53 genes. Cell invasion and migration assays were used to observe the effect of Gli1, MDM2 and p53 silence on cell invasion and migration in p53 wild-type Capan-2 pancreatic cancer cells, respectively. Meanwhile, immunoblotting (IB) was used to detect the protein level of matrix metalloproteinase (MMP) -9, phospho-excelluar signal-regulated kinase (pERK) and phosphorylation protein kinase B (pAKT) in Gli1-silencing Capan-2 cells. The data were analyzed by paired t-test.

RESULTSqRT-PCR showed that the expression of Gli1, MDM2 and p53 is down-regulated 70.5% and 74.5%, 61.8% and 65.3%, and 73.8% and 78.2% after siRNA interference, compared with the mock and siRNA control groups, respectively. Cell invasion (94 ± 8) and migration (143 ± 8) in p53 wild-type Capan-2 cells transfected with Gli1siRNA were significantly decreased, compared with the siRNA control group (150 ± 7, 190 ± 10) (t = 6.584, P = 0.022; t = 8.266, P = 0.014) , while MDM2 silence inhibited cell invasion (experiment group:85 ± 12, control group: 138 ± 6) and migration (experiment group: 127 ± 9, control group:180 ± 10) in the same cells, respectively (t = 5.097, P = 0.036;t = 4.860, P = 0.040). However, cell invasion (experiment group: 153 ± 11, control group: 106 ± 7) and migration (experiment group: 209 ± 13, control group: 164 ± 8) in p53-silencing Capan-2 cells were significantly enhanced (t = 4.669, P = 0.043; t = 4.990, P = 0.038). IB showed that Gli1 silence down-regulated MMP-9 but not pERK and pAKT protein expression.

CONCLUSIONGli1 might contribute to the cell invasion and migration in pancreatic cancer via the regulation of MDM2, p53 and MMP-9 expression.