Objective    To construct an eukaryotic gene expression vector for CD44v6 and its expression in tumor cells.     Methods    (1) CD44v6 gene was amplified by RT-PCR and cloned into plasmid pBud to form a recombinant plasmid pBud-CD44v6

which was then identified by restriction endoenzyme digestion and nucleotides sequencing. (2) The recombinant plasmid of pBud-CD44v6 was transfected into the gastric adenocarcinoma cell line SGC7901 by Lipofectamine 2000

and the expression of CD44v6 was detected by immunohistochemistry.     Results    (1) the restriction digestion and sequence analysis demonstrated that this 129 bp of CD44v6 was the same as that published in GenBank

and it was inserted into the vector accurately. (2) After the SGC7901 cells were transfected with CD44v6

obvious expression of CD44v6 protein was seen in the cytoplasm

while in the control group no brown protein was found.     Conclusion    A new plasmid of pBud-CD44v6 has been successfully established and expressed in tumor cells.