Triplex targeting of human PDGF-B (c-sis, proto-oncogene) promoter specifically inhibits factors binding and PDGF-B transcription
AUTOR(ES)
Liu, Jing
FONTE
Oxford University Press
RESUMO
Human c-sis/PDGF-B proto-oncogene has been shown to be overexpressed in a large percentage of human tumor cells establishing a growth-promoting, autocrine growth circuit. Triplex forming oligonucleotides (TFOs) can recognize and bind sequences in duplex DNA, and have received considerable attention because of their potential for targeting specific genomic sites. The c-sis/PDGF-B promoter contains a unique homopurine/homopyrimidine sequence (SIS proximal element, SPE), which is crucial for binding nuclear factors that provoke transcription. In order to develop specific transcriptional inhibitors of the human c-sis/PDGF-B proto-oncogene, 20 potential TFOs targeting part or all of the SPE were screened by gel mobility analysis. DNase I footprinting shows that the TFOs we designed can form a sequence-specific triplex with the target. Protein binding assays demonstrate that triplex formation inhibits nuclear factors binding the c-sis/PDGF-B promoter. Both transient and stable transfection experiments demonstrate that the transcriptional activity of the promoter is considerably inhibited by the TFOs. We propose that TFOs represent a therapeutic potential to specifically diminish the expression of c-sis/PDGF-B proto-oncogene in various pathologic settings where constitutive expression of this gene has been observed.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=30399Documentos Relacionados
- HindIII polymorphism in the human c-sis proto-oncogene.
- Regulation of expression of the c-sis proto-oncogene.
- Nucleotide sequence of the DNA region immediately upstream of the human c-sis proto-oncogene.
- Enhancement of c-sis proto-oncogene transcription in bronchoalveolar mononuclear cells from patients with pulmonary sarcoidosis.
- The Rep68 protein of adeno-associated virus type 2 stimulates expression of the platelet-derived growth factor B c-sis proto-oncogene.