Two-dimensional polyacrylamide gel electrophoresis analysis of indomethacin-treated human colon cancer cells

Screening for novel protein targets of indomethacin in HCT116 human colon cancer cells using proteomics

Non-steroidal anti-inflammatory drugs, such as indomethacin (IN), inhibit colorectal cancer (CRC) growth through cyclooxygenase (COX)-independent mechanisms, however, the precise biological mechanisms are not completely understood. The aim of the present study was to investigate new molecular factors potentially associated with IN in HCT116 human CRC cells, which do not express COX, using a proteomic approach. The total proteins from the IN-treated and untreated groups were separated by immobilized pH gradient-based two-dimensional gel electrophoresis. The differentially-expressed proteins were identified by peptide mass fingerprint (PMF) based on matrix-assisted laser desorption/ionization time of flight mass spectrometry. The PMF maps were searched in the SWISS-PROT/TrEMBL database using the PeptIdent software. Between the IN-treated and untreated groups, a total of 45 differential protein spots were detected and 15 differentially-expressed proteins were identified by PMF. IN downregulated Wnt1-inducible signaling pathway protein 1, Bcl-2-related protein A1 and mitogen-activated protein kinase, inhibited HCT116 cell growth and induced apoptosis. In conclusion, IN may exert its effects on CRC to induce HCT116 cell apoptosis and suppress growth through COX-independent pathways.

Two-dimensional gels for toxicological drug discovery applications

Two-dimensional gel electrophoresis (2DGE) continues to be a useful approach to study protein expression. Although liquid chromatographic and mass spectrometric approaches that overcome some of the limitations and labour intensity of 2DGE are increasingly popular, this electrophoretic approach still has exceptional relevance in toxicology. Despite the technical challenges, pharmacologists/toxicologists continue to use gel-based proteomics to assess the biological and health effects of chemical treatment and exposure. This brief review addresses the use of 2DGE-based proteomics in drug development and toxicology, emphasising its unique strengths and weaknesses, and considers recent developments in this strategy that have evolved to directly confront the issues of dynamic range and reproducibility that have previously limited the overall use of 2D electrophoresis.

Application of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry for early detection of pancreatic cancer

Pancreatic cancer is a devastating and lethal disease. Early detection continues to be a serious, unsolved problem. However, proteomics is emerging as a powerful new tool for the diagnosis of pancreatic cancer. Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) is a new technique that allows for rapid high-throughput screening of protein expression in clinical samples. The progress and challenges in applying SELDI-TOF MS to protein biomarker discovery in pancreatic cancer are reviewed in this paper.