Plasminogen activator inhibitor-1 is a downstream mediator of the PGP9.5-related oncogenic pathway in esophageal squamous cell carcinoma

BACKGROUND & MATERIALS AND METHODS: Recently, it has been proved that PGP9.5 is an oncogene candidate for squamous cell carcinomas. To examine the PGP9.5-related oncogenic pathway, we tested for global patterns of gene expression in cancer cells following PGP9.5 gene introduction using an oligonucleotide microarray approach. RESULTS: Plasminogen activator inhibitor-1 (PAI-1) was identified as an overexpressed gene in a PGP9.5-expressed esophageal squamous cancer cell line. To confirm the data obtained, we performed Northern analysis using a PGP9.5 or a PAI-1 cDNA probe and found that PAI-1 mRNA was induced by PGP9.5 expression in NUEC1 cells. We further examined endogenous PGP9.5 and PAI-1 expression in 6 esophageal cancer cell lines. One cell line (NUEC2) with PGP9.5 expression exhibited PAI-1 expression, suggesting the possibility that PGP9.5 might induce PAI-1 directly or indirectly. CONCLUSION: These results suggested that PAI-1 might be a novel downstream mediator of PGP9.5 in esophageal squamous cell carcinomas.