Antisense DNA

Antirachitic vitamin Antiredeposition agents Antirust additives Antiscaling additives Antiscorbutic vitamin Antiseize material Antisense agents Antisense DNA... 

Song L, et al. Characterization of the inhibitory effect of PEG-lipid conjugates on the intracellular delivery of plasmid and antisense DNA mediated by cationic lipid liposomes. Biochim Biophys Acta 2002 1558 1. 

Cohen, A. S., Vilenchik, M., Dudley, J. L., Gemborys, M. W., and Bourque, A. J. (1993). High-performance liquid-chromatography and capillary gel-electrophoresis as applied to antisense DNA. 

M. J. Damha, Efficient RNase H-directed cleavage of RNA promoted by antisense DNA or 2 F-ANA constructs containing acyclic nucleotide inserts, J. Am. Chem. Soc., 125 (2003) 654-661. 

Theoretically, mutated or nonfunctional genes could be excised and replaced, and new genes with desired functions could be permanently inserted into the genome. Stable integration of an antisense DNA might also be desirable in some circumstances. Because of the technical difficulties associated with the delivery of nucleic acid-based products selectively to specific target cells in vivo, more experimental information is available for ex vivo human gene therapy. 

Antisense DNA or RNA RNA2 Cytoplasm Translation arrest, RNase H activation, inhibition of splicing, disruption of RNA structure Clinical use3 clinical trials... 

According to the chemical composition, physicochemical and/or biochemical properties, antisense oligonucleotides can be divided into antisense RNA and antisense DNA (Table 3.1). 

Wickstrom, E. (1998) Clinical Trials of Genetic Therapy with Antisense DNA and DNA Vectors. Marcel Dekker, New York. 

Amidinium lipid salts, 315 Anti-MDM2 oligonucleotides, 42 Antisense, 33 Antisense DNA, 37 Antisense RNA, 36 Aptamer, 34, 80 Atopic diseases, 476 Autoimmune diseases, 290 Autoimmune, 508... 

Kutryk MJ, Foley DR van den Brand M, et al. Local intracoronary administration of antisense oligonucleotide against c-myc for the prevention of in-stent restenosis results of the randomized investigation by the Thoraxcenter of antisense DNA using local delivery and IVUS after coronary stenting (ITALICS) trial, J Am Coll Cardiol 2002 39(2) 281 -287. 

Transcription by E. coli RNA polymerase occurs in three phases initiation, elongation and termination. Initiation involves binding of the enzyme to a promoter upstream of the gene. During elongation, the antisense DNA strand is used as the template so that the RNA made has the same base sequence as the sense (coding) strand, except that U replaces T. A termination signal is eventually encountered that halts synthesis and causes release of the completed RNA. 

In the transcription process the two DNA strands are separated and the antisense DNA strand paired with its complementary RNA bases by enzymes called RNA polymerases to produce mRNA that encodes the same sequence of bases as the sense DNA strand. The only difference between the DNA and RNA sequences is that the saccharide section of the nucleoside is ribose rather than deoxyribose and uracil takes the place of thymine. The effects of these changes are that the hydrophobic 5-methyl group of thymine has been removed to generate uracil and a 2 -hydroxy group is present in the linking saccharide (Table 2.4). 

The process of transcription can also occur in reverse, from RNA to DNA, when the sequence coded in RNA is transcribed into antisense DNA by reverse transcriptase enzymes first discovered by Temin and Mizutani [18] and Baltimore [19]. Further integrase enzymes insert the DNA sequence into the native DNA. This is the mechanism by which viruses infect their host organisms and can be stopped by antiviral drugs, such as azidothymine (AZT) that inhibits F1IV reverse transcriptase. Other processes such as the extension of telomeres at the ends of chromosomes by telomerase, to control programmed cell death, use the same mechanism. 

Protein disulfide isomerase (PDI) was found to be important in catalyzing disulfide bond formation of antibody fragments, and it improved the efficiency of E. coli ribosome display of antibodies threefold when used during the in vitro translation reaction (Hanes and Pluckthun, 1997) (see also Section II, B). A fourfold improvement of ribosome display was observed when 1 OSa-RNA, which is involved in degradation of truncated proteins (see Section III, B, 2), was inhibited by using an antisense DNA oligonucleotide directed against the lOSa-RNA (Hanes and Pluckthun, 1997). 

It is more likely that p53 influences repair in a regulatory capacity. One link between p53 and NER was made with the observation that the p5 3-regulated Gadd45 binds to PCNA, a component of both replication and repair [206]. Overexpression of Gadd45 provided a small level of protection from cisplatin [207], whereas Gadd45 antisense DNA sensitized human colon carcinoma cells to cisplatin, an effect which was associated with a decrease in repair [201], It was hypothesized that the Gadd45 protein could interact directly with the repair proteins because it stimulated repair synthesis in nuclear extracts [206] however, this result could not be reproduced under a variety of experimental conditions [208][209], Thus, it seems likely that there are still some as yet unidentified factors which link p53 and the excision repair pathway. 

Functionalized antisense DNAs, chemical syntheses of 90YGK180. 

Nucleotide incorporation is determined by base pairing with the template strand of the DNA. The template is the DNA strand, also called the sense strand, that is copied by the RNA polymerase into a complementary strand of RNA called the transcript. The DNA strand that is not copied is know as the antisense strand. Note that while the RNA chain grows in a 5 to 3 direction the polymerase migrates along the sense strand in a 3 to 5 direction. Thus, the 5 to 3 ribonucleotide sequence of the RNA transcript is identical to the 5 to 3 antisense DNA strand with uracil in place of thymidine. 

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