[Proteome study of colorectal cancer genesis and hepatic metastasis]

To study differential proteins and their biological functions associated with colorectal cancer genesis and hepatic metastasis by proteomics and molecular biology techniques.

Isoelectric focusing/SDS acrylamide gel two-dimensional electrophoresis was used to analyse the expression of differential proteins from normal colorectal mucosa, primary cancer lesion and hepatic metastasis region. Liquid chromatography/mass spectrometry (LC-MS/MS) was used to identify the differential proteins. Transfection of colorectal cancer lovo cells was performed with the differential protein cDNA, and the changes of cell biological behavior was observed.

Significant difference in protein expression was found on two-dimensional electrophoresis. Thirteen differential protein spots were analysed and identified. Human carbonic anhydrase II was detected in normal colorectal mucosa but not in primary cancer lesion and hepatic metastasisnegion. Phosphoglycerate kinase 1, fumarate hydratase and aldolase A were expressed in primary cancer. Expression of homo sapiens arginase and homo sapiens glutathione S-transferase A3 was found in hepatic metastasisnegion, but not in primary cancer lesion. After transfection with human carbonic anhydrase II cDNA, the lovo cells changed obviously with reduction in invasiveness, chemotaxy motor ability and tolerance.

Differential expression of proteins was found between colorectal cancer genesis and hepatic metastasisnegion. No carbonic anhydrase II expression and enhanced expression of sapiens arginase and sapiens glutathione S-transferase A3 are related with biological behavior of colorectal cancer cell and facilitate hepatic metastasis.