Radiation-inducible promoter mediated PUMA Gene in the the treatment of Tca8113

摘要

Objective: The aim of this study is to explore the therapeutic effect of the PUMA gene mediated by ra- diation-inducible promoters in the treatment of ton- gue squamous cell carcinoma. Methods: Recombi- nant pcDNA3.1 (+)/E-PUMA was constructed, in which the PUMA gene was mediated by a synthetic radiation inducible promoter. The recombined plas-mids were transfected into the Tca8113 cell and xeno- grafts of human tongue squamous carcinoma in na- ked mice respectively. After 24 h, the tumors were tr- eated with 3 Gy of irradiation to upregulate the PU- MA gene expression. PUMA mRNA was detected by RT-PCR. Proliferating cell nuclear antigen (PCNA) and apoptosis were detected by immunohistochemi- cal method and in situ end-labeling (ISEL) respecti- vely. The data were analyzed using the SPSS11.0 soft- ware package for chi-square test. RESULTS: Com-pared with the control group, the comparative survi- val rate of Tca8113 cells in the PUMA/IR group was markedly decreased and the xenografts were signify- cantly suppressed. Up-regulation of PUMA gene ex- pression was observed in the Tca8113 cells and in the xenografts after irradiation. The apoptosis indices of the Tca8113 cells and xenograft with irradiation were markedly higher than those without irradiation. At the same time, the proliferation indices of the Tca- 8113 cells and xenografts with irradiation were mark- edly lower than those without irradiation. Conclu- sions: radiation-induc ible promoters can serve as molecular switches to improve the expression of PU- MA gene in tongue squamous cell carcinoma both in vivo and in vitro. Low-dose induction radiation can significantly improve therapeutic efficiency.