OBJECTIVE To study the effects E.coli purine nucleoside phosphorylase suicide gene on human gastric cancer MKN-45 cells as well as the bystander effect.
METHODS The ePNP gene was subcloned to pcDNA3.1 to construct recombinant eukaryotic expression vector pcDNA3.1-ePNP.The recombinant plasmid was transfected into MKN-45 cells by lipofectamin method and positive cell clones were screened with G418.Then MePdR was added to these gene-modified cells and the sensitivity of the cells to MePdR was studied as well as the bystander effect.
RESULTS MePdR treatment of MKN-45/ePNP cells induced cytotoxic and antiproliferative effects in a concentration-dependent manner with 100% cell death since 1 mg?L-1.Bystander effect was strong in vitro as 100% of tumor cells were killed by MePdR with only 10% MKN-45/ePNP cells.The gene-modified gastric cancer cells MKN-45/ePNP were sensitive to the treatment of MePdR compared with unmodified tumor cells,and also a remarkable bystander effect was observed.
CONCLUSION The efficiency of ePNP/MePdR system and the potential feasibility of suicide gene strategy for clinical therapy of human gastric cancer are demonstrated.