Heptamidine is an effective Pentamidine-related inhibitor of the calcium-binding protein S100B (Kd: 6.9 μM). It selectively kills melanoma cells with S100B over those without S100B. It is a useful tool for the investigation of Myotonic dystrophy.

S100B:(kd)6.9 μM

Heptamidine is a Pentamidine-S100B complex, two molecules of pentamidine bind per monomer of S100B, which is used to be an inhibitor for S100B[1]. Heptamidine rescues mis-splicing of minigene reporters in a HeLa cell DM1 model (EC50 value of 15 μM). When compares to Propamidine and Pentamidine, Heptamidine (20 μM) does not reduce CUG levels?obviously. It shows cytotoxic at concentrations above 17.5 μM in HeLa cells expressing 960 CUG repeats[2].

Heptamidine (intraperitoneal injection; 20 or 30 mg/kg; 7 days) induces a dose-dependent reduction of exon 7a inclusion in?HSALR?mice. When at 20 mg/kg dose, returning to wild type levels (6±1%), the myotonia is reduced from grade 3 to grade 1 (occasional myotonic discharge) or grade 0 at both 20 or 30 mg/kg[2].