Overexpression of Bcl-2 as a proxy redox stimulus to enhance activity of non-viral redox-responsive delivery vectors.
Redox-sensitive non-viral delivery systems exploit intracellular reducing environment to improve the efficacy of the delivery of nucleic acids by selectively releasing the cargo in the subcellular space. Bcl-2 overexpression is frequently observed in human cancers and is closely associated with increased resistance to chemotherapy and radiotherapy. One of the biochemical alterations accompanying Bcl-2 overexpression is the increase in cellular glutathione (GSH) levels. In this study, we hypothesize that such increase of GSH concentration will selectively enhance the transfection activity of redox-sensitive delivery systems in cells overexpressing Bcl-2. Transfection studies were conducted in MCF-7 mammary carcinoma cells and MCF-7 clones overexpressing Bcl-2. It was confirmed that Bcl-2 overexpression resulted in the expected increase in GSH concentration. Redox-sensitive complexes containing plasmid DNA, mRNA, antisense oligodeoxynucleotides, and siRNA exhibited selectively increased activity in cells overexpressing Bcl-2 compared to non-redox complexes. The effect of Bcl-2 overexpression on the selective enhancement of transfection was highly dependent on the type of the delivered nucleic acid, and was most pronounced for mRNA. This study shows that Bcl-2 overexpression can serve as a proxy redox stimulus to enhance the activity of all major classes of potential nucleic acid therapeutics, when delivered using redox-sensitive vectors.
Manickam
Devika S
DS
Department of Pharmaceutical Sciences, Wayne State University, Detroit, MI 48202, USA.
Hirata
Aiko
A
Putt
David A
DA
Lash
Lawrence H
LH
Hirata
Fusao
F
Oupický
David
D
D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D002999:Clone Cells; D016895:Culture Media, Serum-Free; D004247:DNA / Q000378:metabolism / Q000627:therapeutic use; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D019254:Genes, bcl-2; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D005978:Glutathione / Q000032:analysis / Q000378:metabolism; D006801:Humans; D016376:Oligonucleotides, Antisense / Q000378:metabolism / Q000627:therapeutic use; D010084:Oxidation-Reduction; D010957:Plasmids / Q000737:chemistry; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism / Q000627:therapeutic use; D034741:RNA, Small Interfering / Q000378:metabolism / Q000627:therapeutic use; D014162:Transfection
D016895:Culture Media, Serum-Free; D016376:Oligonucleotides, Antisense; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D004247:DNA; D005978:Glutathione