cx-4945 (silmitasertib) is a potent and selective casein kinase 2 (ck2) inhibitor with ic50 value of 1 nm. it is atp-competitive and can be taken orally [1].cx-4945 has been reported to have antiproliferative activity against a wide range of tumor cell lines. it is suggested that cx-4945 suppresses the ck2 regulated pi3k/akt signaling pathway by inhibiting akt phosphorylation at serine 129, but not by activating pten. additionally, cells treated with cx-4945 had a reduction of p21 phophorylation and an up-regulations of total p21 and p27. cx-4945 has been shown to induce cell-cycle arrest at g2/m phase in breast cancer cell line bt-474. it also causes cell-cycle arrest at g1 phase the breast cancer cell line bxpc-3) [1].in cx-4945 and bxpc-3 derived mouse xenograft model, cx-4945 induced a reduction of phos-p21 expression along with anti-carcinoma effects [1]
[1] siddiqui-jain a1, drygin d, streiner n, chua p, pierre f, o'brien se, bliesath j, omori m, huser n, ho c, proffitt c, schwaebe mk, ryckman dm, rice wg,anderes k. cx-4945, an orally bioavailable selective inhibitor of protein kinase ck2, inhibits prosurvival and angiogenic signaling and exhibits antitumor efficacy. cancer res. 2010 dec 15; 70 (24): 10288-98.