Transfection of wtp53 and Rb94 Genes Into Retinoblastomas of Nude Mice by Ultrasound-Targeted Microbubble Destruction

Using ultrasound-targeted microbubble destruction (UTMD), we transfected both wild-type p53 (wtp53) and Rb94 genes into retinoblastomas (RBs) of nude mice to investigate the inhibitory role of these two genes in RB development. The 40 tumor-bearing mice, which had been established by sub-retinal injection of an HXO-Rb44 cell suspension, were randomly divided into five groups: blank control group (C); blank plasmid group (M); wtp53 plasmid group (p53); Rb94 plasmid group (Rb94); wtp53 + Rb94 plasmid group (p53 + Rb94). For preparation of the DNA-loaded microbubbles, a pre-determined amount of blank plasmid, pVIVO1-p53, pVIVO1-Rb94 or pVIVO1-p53-Rb94 was added and mixed with the microbubbles. Then, these DNA-loaded microbubbles were respectively transfected into the animal model by UTMD. Vascular endothelial growth factor level and microvessel density of the tumor were determined by immunohistochemical staining. Apoptosis of tissues was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Expression of wtp53 and Rb94 at both the gene and protein levels was detected by RT-PCR (reverse transcription polymerase chain reaction) and Western blot, respectively. Transfection of both genes had greater inhibitory effects on RB development and resulted in lower levels of vascular endothelial growth factor, lower microvessel density and more obvious apoptosis than single-gene transfection (p < 0.05). The results indicate that the transfection of both genes into the RB by UTMD more strongly inhibited RB growth than transfection of a single gene.