DMAT (Synonyms: Casein Kinase II Inhibitor II, 2-Dimethylamino-4,5,6,7-tetrabromobenzimidazole)

IC50 value: 0.13uM. DMAT also displays submicromolar IC50 values with almost all of the other kinases with special reference to PKD1, PIM3 and PIM1[3]. Protein kinase CK2 is involved in cell proliferation and survival, and found overexpressed in virtually all types of human cancer, including breast cancer. We demonstrate that inhibition of CK2 with 2-dimethylamino-4,5,6,7-tetrabromo-benzimidazole (DMAT), a potent and specific CK2 inhibitor, results in caspase-mediated killing of human breast cancer cells with acquired resistance to antiestrogens [1]. In vitro:. Treatment with DMAT decreases the secretion of aldosterone, dehydroepiandrosterone sulfate, and androstendione in H295R human adrenocortical cancer cell line and results in an accumulation of 17-OH-progesterone. Cell growth as measured by the MTT and 5-bromo-2'-deoxyuridine incorporation assays is inhibited, and cell cycle analysis has revealed a slight induction of apoptosis[2]. PIM1 is also inhibited by DMAT by a mechanism which is competitive with respect to ATP. However, IC50 determinations at increasing ATP concentration denote weak competition by ATP which, at almost physiological concentration (0.6 mM), causes only a 5.3-fold decrease in DMAT inhibition, as compared with 1 μM ATP concentration, whereas in the same range of ATP concentration the IC50 with CK2 increases 22.1-fold, doubling the value calculated with PIM1 (1.2 μM) [3]. in vivo: Similar to Sorafenib, DMAT interfered with NFκB activation and Wnt-signaling. Of the kinases inhibited by DMAT at almost equimolar IC50, CK2 and PIM-3 were found to be over-expressed or more active in hepatoma cells and human HCC tissue. Knockdown of PIM-3 or CK2 by shRNA revealed that both kinases are important for hepatoma cell proliferation and survival [4]. DMAT, might represent a promising therapeutic approach in future HCC therapy. Clinical trial: Prostate cancer diagnosis among men with isolated high-grade intraepithelial neoplasia enrolled onto a 3-year prospective phase III clinical trial of oral toremifene[3].