Increased expression of epidermal fatty acid binding protein, cofilin, and14-3-3-sigma (stratifin) detected by two-dimensional gel electrophoresis, mass spectrometry and microsequencing of drug-resistant human adenocarcinoma of the pancreas

In order to study possible mechanisms leading to chemoresistance in pancrea tic adenocarcinoma we examined the global protein expression of pancreatic cancer cells in vitro. We used a cell culture model derived from the adenoc arcinoma of the pancreas (EPP85-181P). A classical multidrug-resistant subl ine, EPP85-181RDB, selected in presence of daunorubicin, and an atypical mu ltidrug-resistant cell variant, EPP85-181RNOV, selected in presence of mito xantrone, were analyzed using two-dimensional electrophoresis. After staini ng and image analysis, spots of interest were isolated using preparative tw o-dimensional electrophoresis and subjected to mass spectrometry and micros equencing. Three proteins, E-FABP, cofilin, and 14-3-3-sigma (stratifin), w ere overexpressed in chemoresistant cell lines. Cofilin was present in both multidrug in chemoresistant cell lines. Cofilin was present in both multid rug-resistant cell lines. E-FABP and 14-3-3-sigma (stratifin) was found to be overexpressed only in the mitoxantrone-selected atypical multidrug-resis tant cell line. The possible significance of these findings is discussed.