Anti-tumor effect of pcDNA3. 1-Egr. 1p-p16 gene combined with radiotherapy in tumor-bearing nude mice / 中南大学学报(医学版)

ABSTRACT

OBJECTIVE@#To investigate the optimal doses of X-ray irradiation and plasmid injection in the anti-tumor effect of the pcDNA3. 1-Egr. 1p-p16 gene combined with radiotherapy in vivo.@*METHODS@#We observed the anti-tumor effect of the pcDNA3. 1-Egr. 1p-p16 gene combined with radiotherapy with different doses of X-ray irradiation (2, 10, 20 Gy) and plasmid injection (10, 20, 30 microg) in nude mice with JF-305 pancreatic carcinoma, and detected the expression of p16 in tumor by RT-PCR.@*RESULTS@#The tumor growth rate of the nude mice irradiated locally with 20 Gy X-rays after the plasmid injection was significantly lower (P < 0.05 ) than that of the nude mice irradiated locally with 2 Gy or 10 Gy X-ray 3 days after the irradiation. The tumor growth rate of the nude mice injected locally with 20 microg or 30 microg plasmid was significantly lower (P <0.05 ) than that of the nude mice injected locally with 10 microg plasmid. Both pcDNA3. 1-Egr. 1p-p16 group and pcDNA3. 1-Egr. 1p-p16 +20 Gy group had p16 mRNA expression, but the mRNA level of pcDNA3. 1-Egr. 1p-p16 +20 Gy group was higher than that of pcD- NA3. 1-Egr. 1p-p16 group.@*CONCLUSION@#In the pcDNA3. 1-Egr. 1p-p16 gene combined with radiotherapy in vivo the optimal dose of X-ray irradiation was 20 Gy and the optimal dose of plasmid injection was 20 microg. The anti-tumor effect of pcDNA3. 1-Egr. 1p-p16 combined with radiotherapy is better than that of radiotherapy or gene therapy alone, which may be related with the enhanced p16 expression in tumor after the irradiation.