ABSTRACT
Objective: To identify mutually regulated proteins in PC-3 and DU145 androgen-independent prostate cancer cell lines treated with 1,5-bis(2-hydroxyphenyl)-1,4-pentadiene-3-one (MS17), and to study the molecular pathways that contributed to the anticancer activity of MS17. Methods: PC-3 and DU145 cells were treated with 3 × EC
ABSTRACT
Objective: To identify mutually regulated proteins in PC-3 and DU145 androgen-independent prostate cancer cell lines treated with 1,5-bis(2-hydroxyphenyl)-1,4-pentadiene-3-one (MS17), and to study the molecular pathways that contributed to the anticancer activity of MS17. Methods: PC-3 and DU145 cells were treated with 3 × EC50 (15 μM) concentration of MS17 for 24 h and were subjected to protein expression profiling using two-dimensional gel electrophoresis and protein identification by mass spectrometry. Selected differentially expressed proteins with significant P-value of P<0.05 and fold change over 1.5-folds were filtered through and ontologically classified. Mutually regulated proteins were ranked by fold change and identified as common protein targets of MS17. Results: Profiling data revealed that, the mutually down-regulated proteins included ACTB and ACTG associated with structural molecule activity, ACTN1 with cell cycle, ACTN4 with cell migration, HNRPK with apoptosis, PLST with morphogenesis and TERA with proteolysis. However, the expressions of CH60 and HS71A respectively associated with response to unfolded protein demonstrated opposing regulation in PC-3 and DU145 cells. Pathway analysis of the differentially expressed proteins in PC-3 cells demonstrated the modulation of top pathways associated with cell-cell adhesion and cytoskeletal organization while in DU145 cells the pathways were associated with proteosomal degradation, regulation of electrolytes and water, regulation control of germ cells and organization of filament assembly/disassembly. Conclusions: The findings of the present study provide an understanding on the anti-tumorigenic activity of MS17 at the proteome level and warrant further research for its potential application for the management and treatment of androgen-independent prostate cancer.
ABSTRACT
Aims: VraSR and GraSR were shown to be important in conferring intermediate vancomycin resistance in VISA. Nevertheless, the exact mechanism modulated by these systems leading to the development of VISA remains unclear. We employed a proteomic approach to determine the VraS and GraR regulons and subsequently derive the possible vancomycin resistance regulatory pathway(s) in the Mu50 lineage of Staphylococcus aureus. Methodology and results: Staphylococcus aureus strains Mu50Ω, Mu50Ω-vraSm and Mu50Ω-vraSm-graRm are isogenic strains with ascending levels of vancomycin resistance. Total proteins were extracted from the 3 strains and trypsin digested prior to protein isolation and identification by LC-ESI MS/MS and PLGS 2.4. Expression profiles of resulting proteins were analyzed using Progenesis LC/MS software. Differential expression profiles revealed 3 regulons, each controlled by VraS (Mu50Ω-vraSm vs Mu50Ω), GraR (Mu50Ω-vraSm-graRm vs Mu50Ω-vraSm) and VraS-GraR (Mu50Ω-vraSm-graRm vs Mu50Ω), respectively. The regulon down-regulated by VraS in Mu50Ω-vraSm were proteins associated with virulence (MgrA, Rot, and SarA), while GraR up-regulated resistance-associated proteins (TpiA, ArcB and IsaA) in Mu50Ω-vraSm-graRm. The VraS-GraR regulon mediated both up-regulation of resistance-associated proteins (ArgF, ArcB, VraR and SerS) and down-regulation of virulence-associated protein GapB. Conclusion, significance and impact of study: Down-regulation of virulence- in concert with up-regulation of resistance-associated proteins appears to be integral for development of intermediate-vancomycin resistance in the Mu50 lineage of S. aureus.