rna pol i

Quarfloxin (CX-3543) is a fluoroquinolone derivative with antineoplastic activity with IC50 values in the nanomolar range in neuroblastoma cells. Quarfloxin disrupts the interaction between the nucleolin protein and a G-quadruplex DNA structure in the ribosomal DNA template.

Toyocamycin (Vengicide) is an adenosine analog produced by Actinomycetes, functioning as an XBP1 inhibitor and inhibiting IRE1α-induced ATP-dependent XBP1 mRNA cleavage (IC50: 80 nM), and induces apoptosis.

Metarrestin (ML246) is a first-in-class perinucleolar compartment inhibitor with a favorable PK profile, which effectively suppresses metastasis. Metarrestin disrupts the nucleolar structure and inhibits RNA polymerase (Pol) I transcription, at least in part by interacting with the translation elongation factor eEF1A2.

BMH-21, a small molecule DNA intercalator, binds ribosomal DNA and inhibits RNA polymerase I (Pol I) transcription and not affects phosphorylation of H2AX.

CX5461 is an rRNA synthesis inhibitor with oral activity that inhibits Pol I-driven rRNA transcription. CX5461 activates the DNA damage response and has antitumor activity in tumors such as ovarian cancer.

POL1-IN-1 (Compound 3A) can effectively inhibit the transcription of RNA polymerase I in the A375 malignant melanoma cell line but has no effect on polymerase II.

Pol I-IN-1 is a potent inhibitor of RNA polymerase I (Pol I), specifically targeting the large catalytic subunit RPA194, with an inhibition concentration (IC50) of 0.21 μM [1].

Pidnarulex HCl is the salt form of CX-5461, a first-in-class non-genotoxic small molecule targeted inhibitor of RNA polymerase I (Pol I) that activates the p53 pathway without causing DNA damage. CX-5461 selectively inhibits rRNA synthesis by Pol I in the nucleolus, but does not inhibit mRNA synthesis by RNA Polymerase II (Pol II) and does not inhibit DNA replication or protein synthesis. Inhibition of Pol I results in nucleolar stress and release of ribosomal proteins (RP) from the nucleolus. The RP bind to Mdm2 and liberate p53 to orchestrate apoptosis in cancer cells. CX-5461 demonstrates a favorable preclinical profile, potently and selectively kills cancer cells, demonstrates robust in vivo efficacy in multiple models, and has demonstrated oral bioavailability in multiple species.

RNA polymerase II-IN-2 (compound 20iii), a potent inhibitor of RNA polymerase II (Pol II) with a K i value of 9.5 nM, exhibits cytotoxicity against cancer cells, demonstrating toxicity levels 2 and 5 times higher than α-amanitin in CHO and HEK293 cells, respectively [1].