Eukaryotic gene targeting

Chen B, Pogue BW, Hoopes PJ, Hasan T (2006) Vascular and cellular targeting for photodynamic therapy. Critical Reviews in Eukaryotic Gene Expression 16 279-305. 

Angiotensin-converting enzymes (ACEs) Eukaryotes ACEs are involved in blood chemistry. They mostly exist at the cell surface as ectoenzymes, where they hydrolyze circulating peptides. Gene-targeting studies in mice have established that the tissue-bound form of ACE controls both blood pressure and renal stmcture and function, although a soluble form of ACE, which is derived from the membrane form through the action of a secretase, is also present in serum and other body fluids. Nonspecific endopeptidase 59, 60... 

RNA interference (RNAi) is a phenomenon comprising the ability of double-stranded RNA (dsRNA) molecules to stimulate eukaryotic gene suppression in a sequence-specific manner. This article will first outline the essential molecular biological principles of RNAi and then focus on RNAi s practical applications. It will explain how dsRNAs can be delivered to or expressed inside mammalian cells, and what considerations are usually taken into account when choosing various RNAi approaches. In addition, the discussion describes how RNAi can be applied in the drug target discovery and validation process, and what potentials RNAi hold as a therapeutic modality. 

Buletic, Z., Soprano, K.J. and Soprano, D.R. (2006) Retinoid targets for the treatment of cancer. Critical Reviews in Eukaryotic Gene Expression, 16, 193-210. 

Nuclear-gene targeting by using single-stranded DNA avoids illegitimate DNA integration in Chlamydomonas reinhardtii. Eukaryotic Cell, 4 (7),... 

Not only eukaryotic cells but also bacteria have successfully been targeted by PNA anhsense strategies. Thus it has been shown that PNA complementary to ribosomal RNA or mRNA encoding an essential fatty acid biosynthesis protein, effectively kills E. coli. Furthermore, it has been shown that PNA directed to the start codon of the y -lactamase gene re-sensitized otherwise resistant E. coli to the antibiohc ampiciUin [64—66]. Conjugating a simple transporter peptide to the PNA increased the potency significantly, and an even more potent antibacterial PNA... 

Smirnova, J. B., Selley, J. N., Sanchez-Cabo, F., Carroll, K., Eddy, A. A., McCarthy, J. E., Hubbard, S. J., Pavitt, G. D., Grant, C. M., and Ashe, M. P. (2005). Global gene expression profiling reveals widespread yet distinctive translational responses to different eukaryotic translation initiation factor 2B-targeting stress pathways. Mol. Cell Biol. 25, 9340-9349. 

DNA plasmid-based treatment ( gene therapy ) is considered an alternative to the one based on classical chemical drugs or proteins recovered from recombinant cells. Treatment of acquired and inherent genetic diseases as well as the use of DNA for the purpose of vaccination are potential applications of plasmid DNA (pDNA). The plasmid carries information that allows protein expression in the targeted human cells as well as eukaryotic regulatory elements and specific prokaryotic sequences that control replication in the host cell, see Fig. 10. Formulation is required for ex- or in-vivo administration. Selected systems for gene expression can be viral or non-viral. 

Regulation of transcription is a central mechanism by which cells respond to developmental and environmental cues. RNA polymerase Il-mediated transcription in eukaryotes is to a large extent regulated at the level of chromatin, which forms a physical barrier for the binding of proteins to the promoter region of a target gene. The basic unit of chromatin is the nucleosome, which consists of an octamer of histone proteins around which the DNA is wrapped (see Fig. la). 

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