GP73 contributes to the sensitivity of cisplatin in esophageal cancer

Background: The prognosis of esophageal cancer patients is poor. Cisplatin (CDDP) is most often used for advanced esophageal cancer; however, the emergence of drug resistance has prevented successful treatment in many cases. Methods: Using microarray analysis, we identified GP73 as a candidate gene that is overexpressed in TE4, an esophageal cancer cell line which is highly resistant to CDDP. We downregulated GP73 expression in TE4 using siRNA methods. To determine the effect of reduced GP73 expression on the proliferation of TE4, we used cytotoxicity assays. Results: Downregulation of GP73 expression using siRNA induced a significant decrease in the IC compared with cells treated with either control siRNA or mock transfection. Conclusions: GP73 is a candidate gene in esophageal cancer that may be the target of future molecular-targeted therapy in combination with CDDP. © Japan Esophageal Society and Springer 2009.