OBJECTIVETo observe the therapeutic effect of CDglyTK gene mediated by radiation-inducible promoters in the treatment of buccal carcinoma in Golden Hamster.

METHODSAnimal models of buccal carcinoma in golden hamster were established by painting 0.5% dimethyl-benzanthracene. The plasmids pcDNA (+) 3.1/E-CDglyTK were transfected into tumors by lipofectamine. 24 h later, the tumors were exposed to 3 Gy irradiation. Animals were monitored at regular intervals for volume of tumors. CDglyTK mRNA was assayed by RT-PCR. Apoptosis and proliferating cell nuclear antigen were detected respectively by in situ end-labeling and immunohistochemical methods.

RESULTSCompared with control groups, the tumor was suppressed obviously by CDglyTK gene therapy combined with 3 Gy induction radiation. The expression of CDglyTK gene could be detected by RT-PCR in the transfected tumor, and up-regulation of CDglyTK expression was found in tumor exposed to radiation (P < 0.05). There was significant difference in apoptosis index or proliferation index between tumor without irradiation and tumor with irradiation (P < 0.05).

CONCLUSIONSThe radiation-inducible promoter can be served as a molecular switch to regulate the expression of CDglyTK gene in buccal carcinoma in golden hamster, and low dose induction radiation can significantly improve the therapeutic effects.