Study On The Inhibition Of Breast Cancer By Double SiRNA Introduced By Adeno-associated Viruses Vector

Objective: The effects of in vivo expressing siRNA on human SATB1 expression in human breast cancer cell line MDA-MB-231 have been studied. The recombinants containing double siRNAs targeting human SATB1 and VEGF have been constructed into Adeno-assosiated virus (AAV) vectors. The inhibition effects on their target genes of both siRNA introduced by recombinant AAV particles has been demonstrated. Methods: After transfected by liposome into MDA-MB-231 cells which highly express SATB1, both real time-PCR and Western-blot analysis were used to evaluate the inhibition of siRNA against human SATB1. The siRNA coding sequences of SATB1 and VEGF genes were amplified through PCR and then inserted into plasmid pAAV-MCS of AAV Helper-free system. Recombinant plasmids were then co-transfected into AAV-293 cells with pAAV-RC and pHelper for recombinant AAV packaging. The expression of siRNAs mediated by AAV was detected in the MDA-MB-231 cells by Real Time-PCR. Results: The recombinant plasmids psiS823, psiS2567, psiS3373 can significantly reduce the expression of SATB1 mRNA and its protein product. The recombinant plasmids pAAV-VESR was verified by enzyme digestion and sequence analysis. Recombinant siRNAs were detected by real time-PCR, indicating recombinant AAV-VESR were successfully packaged and mediating siRNA inhibition. Conclusion: Recombinant AAV was successfully constructed, which may lay a foundation for siRNAs against breast cancer as were as other cancers.