Current Pharmaceutical Biotechnology - Volume 5, Issue 4, 2004

Despite intensive researches aimed at the treatment of relevant human pathologies such as cancer, cardiovascular and virus mediated diseases, optimal drugs have not yet been identified. In this regards, an attractive and novel therapeutic strategy is based on the use of the so called “nucleic acid based drugs”. These molecules, among which the most actual are represented by ribozymes (Rzs), DNAenzymes (DNAzs) and small Read More

DNAzymes, also known as deoxyribozymes or DNA enzymes, refer to single-stranded DNA molecules with catalytic capabilities. DNAzymes are generated de novo by in vitro selection - a powerful and yet simple technique that has been routinely used to isolate extremely rare DNA or RNA sequences with a function of interest (e.g. ligand-binding or catalysis) from an extraordinarily large population of single-stranded DNA or Read More

DNA enzymes, or DNAzymes, are all-DNA molecules with inherent catalytic activity that bind and cleave at their complementary sequence in the target mRNA through Watson-Crick base pairing. These agents have been successfully used to tease out the role the targeted gene plays in both cellular systems and in a variety of animal models. DNAzymes have the potential to serve as novel nucleic acid-based therapeutic agent Read More

RNA interference can induce potent gene silencing through degradation of complementary mRNA. Short double-stranded interfering RNAs are incorporated into an RNA-induced silencing complex that mediates the recognition and degradation of messenger RNAs in a very targeted manner. Though this phenomenon has been described in mammalian cells only a few years ago, there has been an explosion of interest in using Read More

Almost all human cancers have accumulated multiple genetic lesions including oncogenes. It is often unknown whether an oncogene is continuously required for tumorigenesis. Furthermore, it is very difficult to target an essential oncogene with drugs without affecting the corresponding nonmutated protooncogene or related factors. The recent discovery of RNA interference and the application of small interfering RNAs in Read More

RNAi is a powerful cellular mechanism that involves targeted destruction of mRNAs. Although the phenomenon was first discovered in plants and lower eukaryotic organisms, it was later discovered as an important genetic regulatory mechanism in mammalian cells. RNAi is triggered by double stranded RNAs that are cleaved into short 21-23 base pair duplexes by an RNAse III type enzyme called Dicer. The short RNAs, termed s Read More

RNA interference consists of a sequence specific post-transcriptional gene silencing phenomenon triggered by a double strand RNA molecule homologous to the silenced gene. The dsRNA is cleaved by DICER enzyme in small dsRNA pieces, named short interfering RNAs (siRNAs). These fragments are thereafter associated to RISC complex where the cleavage of target RNA occurs. The observation that siRNAs can trigger Read More

The limited efficacy of current therapeutic approaches for a number of socially relevant human diseases such as cancer and cardiovascular pathologies, has required the exploration of alternative and more effective therapeutic strategies. In the last two decades, nucleic acid based drugs have emerged as an attractive and novel alternative with great therapeutic potential. Among these molecules, hammerhead ribozymes Read More

To understand the pathogenesis of a given ion channel disorder, knowledge of the mutation alone is insufficient, instead, the description of the associated functional defect is decisive. The patch clamp technique enables to achieve this both in native tissue as well as heterologous expression systems. By this technique, structure-function relationships of ion channels were elucidated that not only support the homology already Read More

The purpose of this review article is to describe the history of photodynamic therapy (PDT), its current medical applications, the mechanism of action, contraindications of the method, and different types of photosensitizers used. The second part of the article deals with applications for gastrointestinal diseases. The treatment of obstructing oesophageal cancer, early-stage oesophageal cancer, Barrett's esophagus, hilar Read More