Objective    To construct a recombinant adenovirus vector expressing Dickkopf1 (DKK1) (Ad-DKK1) and study the expression of β-catenin in melanoma cells A375 after Ad-DKK1 infection.     Methods    DKK1 gene was amplified by PCR and subcloned to shuttle plasmid Adeasy by molecular cloning and adenovirus recombination technique

then converted in BJAdeasy cells. The recombinant adenovirus plasmid was generated. After cut by PacⅠ enzyme

the recombinant adenovirus plasmid Ad-DKK1 was packaged and amplified in HEK293 cells. Ad-DKK1 effect group

Ad-SimDKK1 effect group

Ad-GFP effect group

Ad-RFP effect group and blank group were used to infect the A375 cells in multiplicity of infection (MOI) 80

and cell morphology was observed. The expression of DKK1 and β-catenin in A375 cells was detected by RT-PCR. Cell vitality was detected by MTT assay.     Results    Ad-DKK1 was proved to be recombined successfully by identification with restriction enzyme and sequencing. The infection was efficient (80%) in A375 cells. The expression of DKK1 had significant difference between Ad-DKK1 effect group (1.638±0.067) and other 4 groups (0.718±0.086

1.424±0.125

1.414±0.089 and 1.423±0.088) (P0.05). The expression of β-catenin had significant difference between Ad-DKK1 effect group (0.590±0.011) and the other 4 groups (0.895±0.012

0.749±0.024

0.754±0.012 and 0.759±0.014) (P0.01). MTT assay indicated that there was significance in cell vitality between Ad-DKK1 effect group (0.370±0.014) and the other 4 groups (0.412±0.017

0.398±0.006

0.395±0.007 and 0.426±0.016)(P0.05).     Conclusion    DKK1-expressing recombinant adenovirus vector is established. Over-expression of DKK1 suppresses the expression of DKK1 and inhibits the expression of β-catenin and cell vitality in melanoma cells.