CX-5461 is a potent and orally bioavailable small-molecule inhibitor of rRNA synthesis that specifically inhibits RNA polymerase (Pol) I-driven transcription with IC50 value of 142 nM. CX-5461 exhibits antiproliferative activity against human pancreatic tumor cells MIA Paca-2, human melanoma cells A375 and colorectal carcinoma cells HCT-116 with EC50 values of 74, 58, and 167 nmol/L, respectively. [1].
CX-5461 was revealed to inhibit Pol I transcription via promoting the stabilization of p53. In addition, CX-5461 has been demonstrated to induce autophagy and senescence but not apoptosis in MIA Paca-2 and A375 cell lines.
In vivo, CX-5461 has shown to suppress tumor volume in both MIA Paca-2 and A375 derived xenograft mice models [1].
References:
[1] Drygin D1, Lin A, Bliesath J, Ho CB, O'Brien SE, Proffitt C, Omori M, Haddach M, Schwaebe MK, Siddiqui-Jain A, Streiner N, Quin JE, Sanij E, Bywater MJ,Hannan RD, Ryckman D, Anderes K, Rice WG. Targeting RNA polymerase I with an oral small molecule CX-5461 inhibits ribosomal RNA synthesis and solid tumor growth. Cancer Res. 2011 Feb 15;71(4):1418-30