Current Drug Targets - Volume 5, Issue 8, 2004

Ribozymes are catalytically active nucleic acids capable of site-specific cleavage of target mRNAs. They have widely been employed as tools in functional studies and for therapeutic purposes. Different classes of ribozymes distinguished by size and mechanism of action have been discovered in natural systems or obtained by in vitro selection. After an introduction to different types of ribozymes with a special focus Read More

Among the technologies available for gene knockdown RNase H-dependent antisense oligonucleotides and RNAi are very popular. Both offer specificity and efficient knockdown of the genes; both are useful tools to study gene functions. Antisense and RNAi methods share many practical problems such as site selection, toxicity at high concentration, and the difficulty of transfection in certain cell types. We will focus in this Read More

The down regulation of gene expression is a promising strategy for molecular medicine and experimental biology. Molecules that bind to the DNA double helix may interfere with gene expression and, in addition to potential therapeutic applications, can be helpful for the investigation of DNA processing, chromatin package, or associated biological processes. Triplex-forming oligonucleotides (TFOs) bind to specific sequences in Read More

Thioaptamers are thiophosphate ester modified nucleic acids that are isolated via in vitro or bead-based thioaptamer selection against a target molecule such as a protein. Thioaptamers offer advantages over traditional aptamers in their enhanced affinity and specificity and higher stability, largely due to the properties of the sulfur backbone-modifications. An in vitro thioaptamer selection procedure that simultaneously selec Read More

Recent progress in cellular and molecular research has provided a new technique to inhibit target gene expression based on DNA technology such as antisense oligodeoxynucleotides (ODN), small interfering RNA (siRNA), ribozyme and decoy ODN. Especially, recently, a successful ODN-based approach termed decoy ODN has used synthetic ODN containing an enhancer element that can penetrate cells, to bind to sequence-spe Read More

Peptide nucleic acids (PNAs)-DNA chimeras have been recently described as DNA mimics constituted of a part of PNA and of a part of DNA. We have demonstrated that double stranded molecules based on PNA-DNA chimeras bind to transcription factors in a sequence-dependent manner. Accordingly, these molecules can be used for transcription factor decoy (TFD) pharmacotherapy. Effects of double stranded PNA-DNA ch Read More

Double-stranded oligodeoxynucleotides (ODN) containing the consensus binding sequence of a transcription factor are valuable tools for the manipulation of gene expression at the transcriptional level by means of the decoy strategy. The approach involves flooding the cells with enough ODN decoy to compete for binding of the transcription factor with its consensus sequence in target genes. The technique has been prov Read More

Positron emission tomography (PET) and single photon emission tomography (SPECT) are high-resolution, sensitive, molecular and functional imaging techniques that permit repeated, noninvasive assessment and quantification of specific biological and pharmacological processes in humans. PET and SPECT are also the most advanced technologies currently available for studying in vivo molecular interactions and the Read More