1 / 20

ANTISENSE AND RIBOZYME TECHNOLOGY

ANTISENSE AND RIBOZYME TECHNOLOGY. Anti-mRNA Strategies. What is the antisense oligonucleotides ?. - Synthetic genetic material. - Interacts with natural genetic material (DNA or RNA) prevent the production of proteins.

kimo
Download Presentation

ANTISENSE AND RIBOZYME TECHNOLOGY

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ANTISENSE AND RIBOZYME TECHNOLOGY

  2. Anti-mRNA Strategies

  3. What is the antisense oligonucleotides? - Synthetic genetic material. - Interacts with natural genetic material (DNA or RNA) prevent the production of proteins.

  4. Antisense Oligonucleotidesare unmodified or chemically modified ssDNA, RNA or their analogs. They are 13-25 nucleotides long and are specifically designed to hybridize to the corresponding RNA by Watson-Crick binding

  5. Mechanism of Action of Antisense Oligonucleotides. 1. Translational Arrest by Blocking the Ribosome. animation

  6. Antisense RNA technology The antisense RNA procedure for blocking or reducing the level of expression of a specific gene.

  7. Mechanism of Action of Antisense Oligonucleotides. 2. Activation of RNase H The enzymeRNaseH is a non- specificendonuclease and catalyzes the cleavage of RNA via a hydrolytic mechanism.

  8. Mechanism of Action of Antisense Oligonucleotides. Ribozymes • Ribozymes are RNA molecules that catalyze biochemical reactions. • Ribozymes cleave single-stranded regions in RNA through transesterification or hydrolysis reactions that result in cleavage of phosphordiester bonds animation

  9. Types of Ribozymes Tetrahymena Group I intron Hammerhead ribozyme Hairpin ribozyme Hepatitis delta virus ribozyme Rnase P

  10. Mechanism of Action of Antisense Oligonucleotides. HammerheadRibozymes • Identification of the minimum ribozyme structure and introduction of chemical modifications that retain ribozyme activity and enhancing stability to nucleases. • Ribozyme-coding sequence has been incorporated into plasmids and administered, in effect ribozyme gene therapy.

  11. Basic features of Hammerhead ribozyme Single strand of RNA. Three helical stem regions. Unpaired loops at the ends of two helices. Helices radiate out from central unpaired core of nucleotides. Cleavage site is next to a small, unpaired "U-turn" loop.

  12. Limitations of Practical Applications of Antisense Oligonucleotides 1. Accessible sites of the target RNA for oligonucleotide binding have to be identified. 2. Antisense agents have to be protected against nucleolytic attack. • Cellular uptake and correct intracellular localization.

  13. Medicinal Chemistry of Antisense Oligonucleotides One of the major challenges for antisense approaches is the stabilization of oligonucleotides, as unmodified oligodeoxynucleotides are rapidly degraded in biological fluids by nucleases.

  14. Application of Antisense Oligonucleotides • Functional Genomics and Target Validation: • Antisense oligonucleotides can be used to selectively manipulate the expression of chosen gene or genes. The process results in : • A pharmaceutical copmoundwith a well-understood mechanism of action. • Well characterized distribution and a safe side effect profile which could be used as a human therapeutic.

  15. Application of Antisense Oligonucleotides • Potential Therapeutic Applications of Antisense Oligonucleotides • A wide variety of potential therapeutic applications of antisense oligonucleotides has been reported in the last few years. • Major areas of these therapeutic applications include: 2.1.Antiviral 2.2. Antibacterial 2.3. CNS Therapeutics: Antisense Oligonucleotides will address unmet medical needsfor CNS diseases.

  16. Potential Therapeutic Applications of Antisense Oligonucleotides 2.4.Inflammation Therapeutics:e.g.Colitis, Lupus, Lung inflammation, Skin inflammation, Transplantation rejection, Reperfusion injury, Rheumatoid Arthritis and Ocular disease. 2.5.Cardiovascular Therapeutics: e.g.prevention of restenosis, myocardial infarction, rejection in heart transplantation, hypertension and atherosclerosis. 2.6.Regulation of Apoptosis: which will address treatment of cancer, psoriasis,fibrosis, atherosclerosis, restenosis and others

  17. Potential Therapeutic Applications of Antisense Oligonucleotides 2.7. Anticancer: 2.8.Other Therapeutic Applications potentials: diabetes, pain and analgesia, psoriasis, myasthenia gravis, hair loss…etc • The most recent antisense application as therapeutic tool is aimed to treat the SARS and bird Flu

  18. Clinical Trials of Antisense Oligonucleotides • One antisense oligonucleotide (fomivirsen) has been approved. • Currently, there are near to 50 antisense compounds in trials for various diseases, up to 10 of which are in phase III, with an additional 20 in Phase II.

  19. Future of Antisense-Based Biotechnology • The clinical experience to date should be considered part of the beginning of the story of antisense treatment, with more clinical trials of new antisense drugs soonexpected. • Currently over 30 pharmaceutical and biotechnology companies have declared an interest in or have an active drug development program already under way in antisense-based therapeutics • The fuller story, yet to be written, promises to be rich. The promise of antisense-based biotechnology is therefore stronger than ever.

  20. THANKS FOR LISTENING

More Related