Leading RNA Interference Therapeutics Part 1: Silencing Hereditary Transthyretin Amyloidosis, with a Focus on Patisiran

AbstractIn 2018, patisiran was the first-ever RNA interference (RNAi)-based drug approved by the US Food and Drug Administration. Now pharmacology textbooks may include a new drug class that  results in the effect first described by Fire and Mello 2 decades ago: post-transcriptional gene silencing by a small-interfering RNA (siRNA). Patients with hereditary transthyretin-mediated amyloidosis (hATTR amyloidosis) present with mutations in the transthyretin (TTR) gene that lead to the formation of amyloid deposits in peripheral nerves and heart. The disease may also affect the eye and central nervous system. The formulation of patisiran comprises the RNAi drug encapsulated into a nanoparticle especially developed to deliver the anti-TTR siRNA into the main TTR producer: the liver. Hepatic cells contain apolipoprotein E receptors that recognize ApoE proteins opsonized in the lipid carrier and internalize the drug by endocytosis. Lipid vesicles are disrupted in the cell cytoplasm, and siRNAs are free to trigger the RNAi-basedTTR gene silencing. The silencing process  involves the binding of siRNA guide strand to 3′-untranslated region sequence of both mutant and wild-typeTTR messenger RNA, which culminates in theTTR mRNA cleavage by the RNA-induced silencing complex (RISC)  as the first biochemical drug effect. Patisiran 0.3 mg/kg is administered intravenously every 3 weeks. Patients require premedication with anti-inflammatory drugs and antagonists of histamine H1 and H...
Source: Molecular Diagnosis and Therapy - Category: Molecular Biology Source Type: research