Antisense Technology: A Selective Tool for Gene Expression Regulation and Gene Targeting

Abstract

This review deals with the antisense technology that, together, forms a very powerful tool to inhibit gene expression and may be used for studying gene function (functional genomics) and for therapeutic purpose (antisense gene therapy). Antisense oligonucleotides block translation of target mRNAs in a sequence specific manner, either by steric blocking of translation or by destruction of the bound mRNA via RNase-H enzyme. For proper designing, accessible sites of the target RNA for binding antisense oligonucleotides have to be identified. Whether being used as an experimental reagent or pharmaceuticals, several problems or drawbacks have to be overcome for successful applications. Toward this direction, various modifications of sugar, bases and phosphate backbone of antisense oligonucleotides have been attempted. In recent years valuable progress has been achieved through the development of advanced cellular delivery systems and novel chemically modified nucleotides with improved properties such as enhanced serum stability, higher target affinity and low toxicity. These qualities and the specificity of binding make this technique a potentially powerful therapeutic tool for gene targeting and/ or expression regulation. This review discusses the basis of structural design, mode of action, chemical modification, enhanced cellular uptake, therapeutic application and future possibilities in the field of advanced antisense technology.

The Current State of Head and Neck Cancer Gene Therapy

“…Intraperitoneal delivery of PTOmodified antisense oligonucleotides demonstrated moderate antitumor effects in HNSCC xenograft tumors (Thomas et al, 2008). Antisense oligonucleotides have many advantages in that they are cost effective, can be synthesized rapidly, they are highly sequence specific, and can be modified to increase serum stability (Sahu et al, 2007). Modifications of oligonucleotides add to the cost of synthesis and may also affect binding to the target or activation of RNase H, an enzyme crucial for degradation of target mRNA (Baker et al, 1997).…”

Inhibitory Effect of p53 Upregulated Modulator of Apoptosis Targeting siRNA on Hypoxia/Reoxygenation-Induced Cardiomyocyte Apoptosis in Rats

“…Optimization of transfection condition is a key step, either directly or indirectly, in the application of the RNAi technique [22,23,24,25]. In this study, such optimization was performed using a combined method, in which fluorescence microscopy was used to directly observe the effectiveness of fluorescent control siRNA transfection, and RT-PCR was used to detect the interference effect of si-PUMA transfection [26,27,28].…”

The Interplay between Epigenetics and Gap Junctional Intercellular Communication

“…In fact, a major challenge lies ahead in fully elucidating the involvement of these molecular mechanisms in connexin expression. A number of tools are now available that will allow clarification of this peritranscriptional crosstalk in GJIC control, including isotype-specific epigenetic modifiers, 138 small interfering RNA duplexes 139 and microRNA inhibitors. 140 At the same time, the use of GJIC suppression as a biomarker for the in vitro detection of epigenetic carcinogenicity should be further explored.…”