About RNA Therapeutics
The Vital Role of RNA
RNA plays a common and vital role in all living organisms. It is a critical element in the process through which cells modulate protein production, a central factor in most human diseases and disorders. Because of this, RNA-based therapeutics hold significant potential as transformative treatment options across a broad range of human diseases and disorders.
DNA, or deoxyribonucleic acid, contains the genetic instructions for regulating protein synthesis. RNA, or ribonucleic acid, is the key tool that executes those instructions. RNA controls protein synthesis through two processes: transcription and translation. Known together as gene expression, transcription and translation are the crucial functions of RNA. Transcription can be understood as the transporting of the information stored in DNA, while translation is the process of protein synthesis.
Because RNA controls protein synthesis, RNA-based therapeutics can theoretically attack almost any disease or disorder in a fundamental manner. The ability to specifically target proteins for down or up regulation (i.e. turning “on” or “off” a targeted protein) confers RNA-based therapeutics unprecedented promise as potential therapeutics. Thus, by targeting RNA and by modulating human biology at its most basic levels, we can directly intervene in the fundamental processes by which diseases and disorders manifest.
About RNA (Ribonucleic acid)
RNA is a chain of ribose rings, each of which is bound to a nucleic acid base (adenine, cytosine, guanine, and uracil). The ribose rings are linked to each other through phosphates. Although similar to DNA in many respects, RNA is usually single-stranded while DNA is usually double-stranded and, where RNA nucleotides contain ribose, DNA contains deoxyribose. Also, RNA has the base uracil rather than thymine that is present in DNA.
There are several different forms of RNA including:
- Messenger RNA (mRNA) delivers the genetic information from the DNA in the cell nucleus to the ribosomes, which are the sites of protein synthesis in the cell.
- Ribosomal RNA (rRNA) is involved in the structural formation of ribosomes, structures that read mRNA.
- Transfer RNA (tRNA) facilitates the linking of individual protein building blocks, or amino acids, to synthesize a protein.
- Small interfering RNA (siRNA) and micro RNA (miRNA) fulfill key functions in the regulation of cellular processes by inhibiting protein synthesis.
- Precursor messenger RNA (pre-mRNA), an immature, single strand of RNA that, when fully processed, becomes mature mRNA.
How RNA Therapeutics Work
RNA–based therapeutic compounds are made up of multiple subunits, or monomers. Each subunit carries a nucleic acid base (adenine, cytosine, guanine, uracil or thymine). These bases can be thought of as a genetic “letter” (i.e. A, C, G, U or T). Each genetic “letter” pairs with its complementary monomer on an RNA target (T or U pairs with A, and G pairs with C). When the monomers are linked together via a chemical structure, or backbone, they are called oligonucleotides. The sequence of these “letters” in an oligonucleotide sequence determine the identity of the RNA to which it binds, as well as the precise position in the sequence of the RNA that it specifically recognizes.
By creating an oligonucleotide sequenced to target the RNA of a therapeutically significant protein for a given disease or condition, RNA-based therapies have the potential to modulate protein synthesis and achieve a beneficial clinical result. Depending on whether up or down regulation of a protein is sought, the type of RNA targeted can vary.
This page was last updated on July 22, 2010.
