Suramin is a polysulfonated naphthylurea with various biological activities. Suramin is a DNA topoisomerase II inhibitor with an IC50 of 5 μM. IC50: 5 μM (DNA topoisomerase II)[3]
Suramin inhibits cell proliferation and DNA synthesis in cultured HeLa cells. The replication of SV40 DNA is completely abolished by 40 μM suramin. DNA polymerase α is sensitive to lower concentrations of suramin (IC50=8 µM) than is DNA polymerase δ (IC50=36 µM), whereas DNA polymerase β is relatively insensitive to the drug (IC50 of 90 µM)[1]. Suramin is a potent inhibitor of DNA strand exchange and ATPase activities of bacterial RecA proteins. Suramin inhibits RecA-catalysed proteolytic cleavage of the LexA repressor. The mechanism underlying such inhibitory actions of suramin involves its ability to disassemble RecA-single-stranded DNA filaments[2]. Suramin is a potent inhibitor of the nuclear enzyme DNA topoisomerase II. Suramin inhibits purified yeast topoisomerase II with an IC50 of about 5 μM[3].
Treatment with suramin shows lower values for pulmonary artery pressure, right ventricular hypertrophy, and distal vessel muscularization on day 21 compared to control rats. Suramin treatment suppresses PA-SMC proliferation and attenuates both the inflammatory response and the deposition of collagen[4].
[1]. Jindal HK, et al. Suramin affects DNA synthesis in HeLa cells by inhibition of DNA polymerases. Cancer Res. 1990 Dec 15;50(24):7754-7. [2]. Nautiyal A, et al. Suramin is a potent and selective inhibitor of Mycobacterium tuberculosis RecA protein and the SOS response: RecA as a potential target for antibacterial drug discovery. J Antimicrob Chemother. 2014 Jul;69(7):1834-43. [3]. Bojanowski K, et al. Suramin is an inhibitor of DNA topoisomerase II in vitro and in Chinese hamster fibrosarcomacells. Proc Natl Acad Sci U S A. 1992 Apr 1;89(7):3025-9. [4]. Izikki M, et al. The beneficial effect of suramin on monocrotaline-induced pulmonary hypertension in rats. PLoS One. 2013 Oct 15;8(10):e77073.