Tuning the Linker Improves RNA-Degrading Drugs Targeting cMYC
- RIBOTACs (ribonuclease-targeting chimeras) are heterobifunctional small molecules that recruit an endogenous ribonuclease to degrade a chosen RNA, rather than inhibiting a protein directly.
- This study applies the approach to cMYC mRNA; cMYC is an oncogenic transcription factor long considered "undruggable" because no direct small-molecule inhibitors have reached clinical use.
- Researchers systematically varied the length and rigidity of the linker connecting the RNA-binding ligand to the ribonuclease-recruiting moiety.
- Linker geometry proved to be a key determinant of how efficiently the RIBOTAC promotes cMYC mRNA degradation.
- Optimized linkers translated into improved downstream modulation of cMYC protein levels in cell-based assays.
- The findings support linker engineering as a general design lever for RIBOTAC-based RNA-targeted therapeutics.
cMYC is the target every med chemist has scars from — decades of "undruggable" transcription-factor programs that went nowhere, so any credible new handle gets attention. What's genuinely useful here isn't the RIBOTAC concept itself but the linker SAR: length and rigidity dominating degradation efficiency is exactly the PROTAC linkerology lesson replaying in RNA-target space, and it's reassuring that the same design intuition transfers. That said, don't lose sight of the tractability problem — these are still bifunctional, comfortably-beyond-Ro5 molecules with the synthetic and PK baggage PROTACs never fully shook off. And the data are cell-based potency, not in vivo proof of concept; going from "degrades cMYC mRNA in a dish" to "a dosable, selective drug" is still the hard part nobody's solved for this target.
Linker Optimization of cMYC RIBOTAC for Efficient cMYC Modulation ↗