Proteomic analysis of differentially expressed proteins between metastatic and non-metastatic human colorectal carcinoma cell lines

To explore the expressions of metastasis-related proteins between metastatic LS174T and non-metastatic SW480 human colorectal carcinoma cell lines.

Two-dimensional gel electrophoresis (2-DE) was applied to separate the total proteins of cells. The silver-stained gels were analysed by 2-DE software Image Master 2D Elite. Selected differential protein spots were identified with peptide mass fingerprinting based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and database searching.

The protein endothelial cell growth factor 1 (platelet-derived), rhotekin protein (RTKN), septin 1, cyclin-dependent kinase 1, sialic acid binding Ig-like lectin 11, tyrosinase-related protein-2, translin-like protein, and DNA directed RNA polymerase II polypeptide J-related gene isoform 2 appeared in metastatic but were not detected in non-metastatic cell lines, whereas integrin-linked kinase-associated protein phosphatase 2C isoform 2, MHC class I promoter binding protein, protein phosphatase 2A regulatory subunit B' (PR 53), carboxypeptidase A5, paired box transcription factor, zinc finger protein 79, and apolipoprotein B-48 were detected in non-metastatic but were absent in metastatic cell lines. In addition, cyclin fold protein 1 variant A and pre-B-cell leukemia transcription factor 1 were lowly expressed in the non-metastatic cell line and were significantly upregulated in the metastatic cell line. These identified proteins were involved in cell growth, motility, invasion, adhesion, apoptosis and tumour immunity, which is associated with distinct aspects of tumour metastasis.

These data are valuable for the identification of differentially expressed proteins involved in human colorectal carcinoma carcinogenesis and metastasis.