Researchers Identified New RNA Polymerase I Inhibitor
The compound JP-1302 disrupts cancer cell proliferation by suppressing ribosomal RNA synthesis and destabilizing key proteins.
Updated on Sept. 30, 2026 in Biotech
Researchers have identified JP-1302, a 9-anilinoacridine derivative that suppresses RNA polymerase I-driven 47S pre-rRNA synthesis. This experimental compound induces nucleolar stress and targets the catalytic subunit of the polymerase, offering a new potential mechanism for intervention in cancer cell lines.
Why it matters
Cancer cells frequently upregulate ribosomal RNA synthesis to maintain their rapid proliferation rates. By specifically targeting the machinery required for this process, the compound provides a mechanism to disrupt the growth cycle of malignant cells.
JP-1302 acts as an inhibitor of RNA polymerase I transcription, specifically suppressing 47S pre-rRNA synthesis at submicromolar-to-low-micromolar levels. The compound maintains selectivity, requiring a higher concentration of 5-10 micromolar to inhibit RNA polymerase II.
The details
The compound functions by displacing POLR1A—the catalytic subunit of RNA polymerase I—from the rDNA promoter, resulting in the proteasome-dependent degradation of the protein. This process leads to the loss of nascent EU-labelled rRNA and the physical disruption of nucleolar morphology. At higher concentrations, the molecule triggers additional cellular stress by causing the covalent trapping of topoisomerase enzymes TOP2A and TOP2B, while simultaneously increasing the chromatin enrichment of FACT subunits SSRP1 and SPT16.
Timeline
- 2026-09-30
Findings regarding the inhibitory mechanism of JP-1302 were published.
The Tech Race
This development joins a crowded field of studies focused on disrupting ribosome biogenesis to starve cancer cells. The identification of JP-1302 as a molecule capable of crossing the blood-brain barrier marks a specific competitive advantage over larger or more polar inhibitors currently in research.
This discovery remains in the research stage and has no immediate application for patients or clinical practice. Researchers are currently limited to observations in cell lines, meaning future translation to human trials remains a distant prospect.
The takeaway
The research establishes that JP-1302 effectively destabilizes the Pol I machinery through proteasomal degradation. Future studies will need to determine if this mechanism can be safely replicated in preclinical animal models without the toxicities associated with high-concentration off-target effects.
Further reading
For more research on targeted molecular interventions, visit our section on Biotech.
Source note: This article includes information reported by Nature.
