RPA Inhibitor, TDRL-505

A cell-permeable quinolinyl-dihydropyrazolyl-oxobutanoic acid compound that is shown to target human Replication Protein A (RPA) via primarily the oligosaccharide/oligonucleotide-binding (OB) folds of DNA-bonding domains A & B (DBD-A/B) in the p70 subunit, effectively inhibiting its DNA-binding activity as well as that of Schizosaccharomyces pombe telemere end-binding protein Pot1 (IC₅₀= 12.9 µM and 15.7 µM, respectively), but not Xeroderma pigmentosum group A protein (XPA) involved in the nucleotide excision repair (NER) pathway or E. coli SSB. Reported to induce cell cycle G1-arrest and decrease Annvex V^-/PI^- healthy cell population (by 50%; 30.8 µM for 48 h) in H460 non-small cell lung carcinoma (NSCLC) cultures with minimal cytotoxicity against freshly isolated human PBMC. Potentiates cisplatin (Cat. No. 232120) and etopside (Cat. No. 341205) cytotoxicity in H460 cultures in a synergistic manner.

A cell-permeable quinolinyl-dihydropyrazolyl-oxobutanoic acid compound that is shown to target human Replication Protein A via primarily the oligosaccharide/oligonucleotide-binding (OB) folds of DNA-bonding domains A & B (DBD-A/B) in the p70 subunit, effectively inhibiting its DNA-binding activity as well as that of Schizosaccharomyces pombe telemere end-binding protein Pot1 (IC₅₀= 12.9 µM/25 nM hRPA/25 nM 34-base AG-rich ssDNA and 15.7 µM/20 nM SpPot1 DBD/25 nM 15-base ssDNA), but not Xeroderma pigmentosum group A protein (XPA) involved in the nucleotide excision repair (NER) pathway or E. coli SSB (20% inhibition at 100 µM against 3.3 nM EcSSB & 25 nM 3Pc3 ssDNA binding). Reported to cause decreased nuclear RPA staining (50 µM for 3 h), cell cycle G1-arrest (75 to 100 µM), and a drop in Annvex V^-/PI^- healthy cell population (by 50%; 30.8 µM for 48 h) in H460 non-small cell lung carcinoma (NSCLC) cultures with minimal cytotoxicity against freshly isolated human PBMC. Potentiates cisplatin (Cat. No. 232120) and etopside (Cat. No. 341205) cytotoxicity in H460 cultures in a synergistic manner, consistent with blockage of RPA-mediated NER pathway.

Cell permeable: yes

Primary Target
Replication Protein A

Reversible: yes

Target IC₅₀: 12.9, 15.7 and 30.8 &micro

Packaged under inert gas

Toxicity: Standard Handling (A)

Use only fresh DMSO for reconstitution.

Anciano Granadillo, V.J., et al. 2010. J. Nucleic Acids2010, 304035.

Shuck, S.C., and Turchi, J.J. 2010. Cancer Res.70, 3189.

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany