Proteomic analysis of gemcitabine-induced drug resistance in pancreatic cancer cells

Abstract

Currently, the most effective agent against pancreatic cancer is gemcitabine (GEM), which inhibits tumor growth by interfering with DNA replication and blocking DNA synthesis. However, GEM-induced drug resistance in pancreatic cancer compromises the therapeutic efficacy of GEM. To investigate the molecular mechanisms associated with GEM-induced resistance, 2D-DIGE and MALDI-TOF mass spectrometry were performed to compare the proteomic alterations of a panel of differential GEM-resistant PANC-1 cells with GEM-sensitive pancreatic cells. The proteomic results demonstrated that 33 proteins were differentially expressed between GEM-sensitive and GEM-resistant pancreatic cells. Of these, 22 proteins were shown to be resistance-specific and dose-dependent in the regulation of GEM. Proteomic analysis also revealed that proteins involved in biosynthesis and detoxification are significantly over-expressed in GEM-resistant PANC-1 cells. In contrast, proteins involved in vascular transport, bimolecular decomposition, and calcium-dependent signal regulation are significantly over-expressed in GEM-sensitive PANC-1 cells. Notably, both protein-protein interaction of the identified proteins with bioinformatic analysis and immunoblotting results showed that the GEM-induced pancreatic cell resistance might interplay with tumor suppressor protein p53. Our approach has been shown here to be useful for confidently detecting pancreatic proteins with differential resistance to GEM. Such proteins may be functionally involved in the mechanism of chemotherapy-induced resistance.

Quercetin-induced cardioprotection against doxorubicin cytotoxicity

“…The detailed experimental procedures were described in our previous reports [20-22]. All primary antibodies used for expression validation were purchased from Genetex (Hsinchu, Taiwan).…”

Hyaluronic acid‐dependent protection against UVB‐damaged human corneal cells

“…Immunoblotting analysis was used to validate the differential abundance of mass spectrometry identified proteins. The detailed experimental procedures were described in our previous reports [Chen et al, ; Hung et al, ; Lin et al, ]. All of primary antibodies used for expression validation were purchased from Genetex (Hsinchu, Taiwan).…”

“…In this study, the cellular targets of UVB‐irradiation of corneal cells were monitored by lysine‐labeling 2D‐DIGE [Chan et al, ; Huang et al, ; Lai et al, ; Chen et al, ; Hung et al, ; Chou et al, ; Wu et al, ]. These strategies combined with MALDI‐TOF MS were used to determine whether cellular protein abundance was altered.…”

Proteomic analysis of UVB-induced protein expression- and redox-dependent changes in skin fibroblasts using lysine- and cysteine-labeling two-dimensional difference gel electrophoresis

“…In the present study, the cellular targets of UVB-irradiation of skin fibroblasts were monitored by lysine-and cysteinelabeling 2D-DIGE [21,22]. These strategies combined with MALDI-TOF MS were used to determine whether cellular protein abundance and thiol reactivity were altered.…”