Abstract: ObjectiveTo investigate the effects of exogenous wild DCC gene stably transfection on growth of colorectal carcinoma cell line SW1116 in vitro. MethodsDCC gene domain was amplified from human normal colon tissue by reverse transcriptpolymerase chain reaction (RTPCR). At first, a recombinant expression plasmid pcDNA3.1(+)DCC was constructed. Human colorectal carcinoma cell line SW1116 without DCC gene was transfected with pcDNA3.1DCC. Cell viability was tested by methyl thiazolyl tetrazolium (MTT) assay. Immunofluorescence staining was used to determine the effects of pcDNA3.1DCC and expression of carcinoembryonic antigen (CEA) in human colorectal carcinoma cell line SW1116 which was transfected with pcDNA3.1DCC. ResultsThe population of cells transfected with pcDNA3.1(+)DCC plasmid was lower than those with pcDNA3.1(+)DCC plasmid and normal cells (t=3.645, P＜0.05; t=3.132, P＜0.05) at 3～6 days after transfection, and the proliferation rate of cells transfected with pcDNA3.1(+)DCC plasmid was lower than those with pcDNA3.1(+) plasmid and normal cells (t=2.134, P＜0.05; t=2.736, P＜0.05). Cell line SW1116 transfected with pcDNA3.1(+)DCC plasmid total viability was lower than normal cells (t=3.053 ,P＜0.05) at 2～6 days after transfection. Cell line SW1116 transfected with pcDNA3.1(+)DCC plasmid total viability was lower than those with pcDNA3.1(+) plasmid (t=2.816, P＜0.05) at 2, 4, 5, 6 days after transfection. The population of flavogreen colour cells transfected with pcDNA3.1(+)DCC plasmid and the fluorescent intensity of these cells were lower than those with pcDNA3.1(+) plasmid and normal control cells. ConclusionTransfected DCC gene can suppress the cell proliferation and make CEA expression of cell line SW1116 down regulation to weaken its infiltration and metastasis abilities.

Key words: Colorectal neoplasms, Transfection, DCC gene