Abstract

Laser capture microdissection and two-dimensional difference gel electrophoresis were used to establish the proteomic profiles for tumor and matched adjacent tissues from 12 patients. Differential protein spots were identified by mass spectrometric analysis. The cDNA of the differential protein was transfected into colorectal cancer cells, and the biological behavior of these cells was observed. The proteomic profile in colorectal cancer tissues was significantly different from that in normal adjacent tissues. There was a 1.5-fold difference and 60 differential protein spots between cancer and adjacent tissues. Ten differential protein spots were analyzed. Among them, two protein spots were down-regulated and eight protein spots were up-regulated in the primary tumor tissues. After identification by mass spectrometry, the two down-regulated proteins were carbonic anhydrase II and protein disulfide isomerase, and these eight up-regulated proteins included APC-stimulated guanine nucleotide exchange factor, phosphoglycerate kinase 1, fumarate hydratase, aldolase A, activator protein 2B, glutathione S-transferase A3, Arginase and zinc finger protein 64 homolog. After been transfected with carbonic anhydrase II, the invasive ability, mobility and drug resistance of colon cancer lovo cells were significantly reduced. The proteomic profile was significantly different between colorectal cancer tissues and normal adjacent tissues. The down-regulation of carbonic anhydrase II and protein disulfide isomerase and up-regulation of APC-stimulated guanine nucleotide exchange facto, aldolase A, glutathione S-transferase A3 and arginase were correlated with the onset of colorectal cancer.

Key words: Colorectal cancer, proteomics.

Abbreviation

CRC, Colorectal cancer; 2DE, two-dimensional gel electrophoresis; MS, mass spectrometric; LCM, laser capture microdissection; 2D DIGE,  two-dimensional differential in-gel electrophoresis; DDT,dichlorodiphenyltrichloroethane; SDS-PAGE, sodium dodecyl sulfate-polyacrlamide gel electrophoresis; LC-MS/MS, liquid chromatography-tandem mass spectroscopy; PDI, protein disulfide isomerase; GEF, guanine nucleotide exchange factor; GST A3, glutathione S-transferase A3; EDTA, ethylenediamine tetra acetic acid; PBS, phosphate-buffered saline.