Platform for Aptamer-Mediated Cellular Regulation using Circular RNA Nanodevices

Background & Unmet Need

• RNA aptamers are small RNAs capable of folding into complex structures, allowing them to bind to metabolites, proteins, or other molecules and thereby regulate cellular functions
• Various aptamers have been successfully selected against different targets and show promise as a diagnostic, prognostic and therapeutic
• Efficient RNA circularization has led to the development of aptamers resistant to exonucleases, making them highly stable and abundant within cells
• However, their constitutive binding can lead to toxicity
• Allosteric control by theophylline and tetracycline binding aptamers is possible but leads to unwanted biological effects, such as increased cyclic AMP and altered microbiomes and antibiotic resistance
• Unmet Need: Reliable method to control the activity of RNA aptamers in a reversible and tunable manner with minimal off-target effects

Technology Overview

• The Technology: A platform for generating acyclovir-controlled RNA nanodevices that can be used for controlling cell physiology
• The nanodevice incorporates two aptamers: the first aptamer (input) exhibits a conformational change upon binding acyclovir, which stabilizes the second aptamer (output) in a folded conformation that binds to an effector or performs an effector function
• PoC Data: Engineered an RNA nanodevice that successfully demonstrated acyclovir-dependent control of Broccoli, a fluorogenic aptamer
• Engineered an RNA nanodevice containing an iron response element (IRE), an aptamer that binds to the major undruggable iron-regulatory proteins (IRPs), enabling tunable repression of free iron levels and thus the inhibition of ferroptosis
• Compared to samples without acyclovir, those with acyclovir exhibited up to a 126% increase in FTH levels and up to a 22% decrease in TfR expression

Technology Applications

• A platform for developing RNA-based therapeutics, particularly for controlling iron homeostasis and preventing ferroptosis
• Integrated into existing gene therapy platforms to enhance the control of gene expression
• As a tool in for studying cellular processes and pathway regulations

Technology Advantages

• Reversible and tunable control of aptamer function through external activators, allows for precise modulation and reset of expression
• Activation by specific, non-toxic small molecules like acyclovir ensures targeted action with minimal side effects
• Applicable to various cellular functions including mRNA cleavage, splicing, and polyadenylation