[Killing effect improved by fusion gene HRE1.Egr-1. yCDglyTK on gene-radio therapy of nasopharyngeal cancer in vitro].

Objective: To construct hypoxia/radiation inducible promotor HRE1.Egr-1, and to observe its promotive effect on the expression of yCDglyTK gene in nasopharyngeal cancer HNE-1 cells and the anti-tumor effect of yCDglyTK and to lay an experimental foundation for further exploration of new gene-radio therapy of nasopharyngeal cancer.

Methods: pcDNA3.1(-)HRE1.Egr-1.yCDglyTK was constructed by gene recombination technique. Stable yCDglyTK-expressing HNE-1 cells were generated by transfecting the recombinant plasmid into the target cells with liposome. The expression of yCDglyTK was detected by Western blot in 4 groups: a normoxia group, a radiation group, a hypoxia group, and a hypoxia and radiation group. The killing effect of 5-FC in different circumstances was determined by MTT.

Results: The expression of yCDglyTK/5-FC gene in all the groups was significantly different(P<0.01),especially in the hypoxia and radiation group. The killing effect of 5-FC on HNE1 cells varied under different conditions, especially in the hypoxia and radiation group.

Conclusion: Hypoxia and radiation can induce the activity of fusion promoter HRE1.Egr-1, and obviously promote the anti-tumor effect of yCDglyTK/5-FC system, suggesting that yCDglyTK may be a candidate suicide gene for gene-radio therapy of NPC.