Impact of calcium ion on cytotoxic effect of the boroxine derivative, K[BOFOH].

The effect of Ca ions on the cytotoxic ability of boron heterocyclic compound dipotassium-trioxohydroxytetrafluorotriborate (K[BOFOH]), on in vitro tumor cells (mammary adenocarcinoma 4T1, melanoma B16F10 and squamous cell carcinoma SCCVII) and non-tumoral fibroblast cells (mouse dermal L929 and hamster lung V79) was examined. At small concentrations of Ca ions (0.42 mM), K[BOFOH] (3.85 mM) has a very strong cytotoxic effect on all cancer cells tested (89.1, 85.6 and 84.6%) and significantly less effect on normal cells (19.5 and 24.2%), respectively. Applying larger concentrations of Ca ions (9.42-72.42 mM), at the same concentration of K[BOFOH], no significant cytotoxic effect was detected on cancer cells and normal cells investigated. The selective ability of K[BOFOH], in the medium with a low concentration of Ca ions has a strong cytotoxic effect on cancer cells and very weak effect in normal cells, opens up the possibility of its application in antitumor therapy.