In vivo study on adenovirus mediating Smad 7 gene expression regulated by radiation via Egr-1 promoter / 中华放射肿瘤学杂志

ABSTRACT

Objective To investigate the time-effect relationship and dose-effect relationship of the expression of adenovirus mediating Smad 7 gene regulated by irradiation via Egr-1 promoter in the lung of C57BL mice. Methods Recombinant adenovirus (AD.Egr-Smad 7) was made up through replication-defective adenovirus enclosed radio-inducible elements from the Egr-1 gene promoter and cDNA encoding Smad 7. Mice infected by intratracheal instillation with AD.Egr-Smad 7 were irradiated to their whole lungs after 24 hours. 324 mice were randomly divided into 6 groups, and the lungs were harvested at different time points following irradiation with single dose of 8?Gy to observe the time-effect relationship of Smad7 gene expression with different time intervals. 108 mice randomly divided into 3 groups were irradiated respectively by different single irradiation dose and the lungs were harvested 5 hours after radiation to evaluated the dose-effect relationship of Smad 7 gene expression with different radiation doses. The expression of exogenous Smad 7 was detected by Western blot analysis. Results The expression of adenovirus mediating Smad 7 gene regulated by Egr-1 promoter could be induced by radiation markedly as compared with the control groups(P