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Purpose: 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.Methods: 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.Results: 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.Conclusion: IRF-2 may inhibit GC progression by down-regulating MMP-1 level. [ABSTRACT FROM AUTHOR]

The epithelial-mesenchymal transition (EMT) plays a crucial role in pancreatic ductal adenocarcinoma (PDAC) development and progression. TWIST activated by intra-tumoral hypoxia functions to promote the EMT. We hypothesized that TWIST and the downstream gene pathway could mediate PDAC progression under hypoxia. Therefore, 90 PDAC tissue specimens were immunostained for TWIST and other proteins. Pancreatic cancer cell lines were used for in vitro experiments and nude mice were used to confirm the in vivo data. Expression of TWIST and HIF-1α proteins was significantly upregulated, whereas expression of E-cadherin and p16 was down-regulated in PDAC tissues compared to that of non-tumor tissues and in tumor tissues obtained from patients with tumor involving splenic artery than those without splenic artery involvement. Up-regulated TWIST in tumor tissues were associated with worse prognosis in PDAC patients. The in vitro data showed that HIF-1α-induced TWIST overexpression promoted tumor cell growth and EMT under a hypoxic condition via TWIST interaction with Ring1B and EZH2. In vivo data showed that TWIST overexpression or a hypoxic condition induce xenograft growth, abdominal metastasis and low mouse survival, whereas knockdown of either Ring1B or EZH2 expression suppressed tumor xenograft growth and metastasis and prolonged survival of nude mice. TWIST was the key player in promotion of pancreatic cancer development and metastasis under a hypoxic condition through interaction with Ring1B and EZH2 to regulate expression of E-cadherin and p16 proteins in pancreatic cancer cells. [ABSTRACT FROM AUTHOR]