IRF-2 Inhibits Gastric Cancer Invasion and Migration by Down-Regulating MMP-1

The interferon regulatory factor 2 (IRF-2) acted as a tumor suppressor. We inspected IRF-2 as a predictor of prognosis in gastric cancer (GC) patients and tried to find out the potential molecular mechanism.

In this study, the association between IRF-2 expression and clinical or prognosis significance was investigated in 86 pairs of tumor and the adjacent normal gastric tissues from GC patients. After establishing the stable cell lines, the Transwell assays were deduced to evaluate the malignancy of tumor. Then, microarray assay was carried out and the GO/KEGG pathway analyses were conducted to identify IRF-2's target gene. The relationship between IRF-2 and matrix metalloproteinases 1 (MMP-1) was also investigated by the immunohistochemistry in 15 pairs of tumor and adjacent normal gastric tissues.

We found that IRF-2 expression level in GC was significantly correlated with the prognosis of the patients. Transwell assays suggested an impaired ability of invasion and migration in IRF-2-overexpressed GC cells and a progressive malignant phenotype in IRF-2-knockdown GC cells. Ninety differentially expressed genes were found between IRF-2-overexpressed GC cells and its normal control sets by microarray. We demonstrated that MMP-1 was canonical in the network of differentially expressed genes by GO and KEGG pathway analysis and its expression level was markedly decreased in IRF-2-overexpressed cells of MKN-45 and increased in IRF-2-knockdown cells of SGC-7901. The expression of MMP-1 was inversely correlated with IRF-2 in GAC TMA specimens.

IRF-2 may inhibit GC progression by down-regulating MMP-1 level.