Proteomic investigation of 5-fluorouracil resistance in a human hepatocellular carcinoma cell line.

Multi-drug resistance (MDR) is a major obstacle towards a successful treatment of hepatocellular carcinoma (HCC). The mechanisms of MDR are intricate and have not been fully understood. Therefore, we employed a cell-line model consisting of the 5-fluorouracil (5-FU) resistant BEL7402/5-FU cell line and its parental BEL7402 cell line. Using relative and absolute quantification (iTRAQ)-coupled 2D LC-MS/MS, a successfully exploited high-throughput proteomic technology, in total, 660 unique proteins were identified and 52 proteins showed to be differentially expressed in BEL7402/5-FU compared with BEL7402. Several differentially expressed proteins were further validated by Western blot and real-time quantitative RT-PCR analysis. Furthermore, the association of MDR with ANXA3, one of the highly expressed proteins in BEL7402/5-FU, was verified. Our study represents the first successful application of iTRAQ technology for MDR mechanisms analysis in HCC. Many of the differentially expressed proteins identified had not been linked to MDR in HCC before, which provide valuable information for further understanding of MDR.