DN604: A platinum(II) drug candidate with classic SAR can induce apoptosis via suppressing CK2-mediated p-cdc25C subcellular localization in cancer cells.

DN604, a carboplatin analogue with a functional dicarboxylato ligand, was deeply investigated to explore its ability to induce apoptosis as well as its antitumor mechanism of action. Both in vitro and in vivo assays indicated that DN604 could effectively inhibit cell viability of SGC-7901 gastric cancer cells and exhibited stronger antitumor activity than carboplatin and comparable activity to cisplatin. Significantly in contrast to cisplatin, DN604 resulted in negligible toxic effects in vivo with the same tumor growth inhibition effect as cisplatin. The mechanism study indicated that DN604 inhibited CK2-phosphorylated cdc25C activation to decrease p-cdc25C subcellular localization, leading to the inactivation of cdc2/Cyclin B and G2/M cell cycle arrest and apoptosis in SGC-7901 cancer cells. Our research revealed for the first time that the dicarboxylato ligand containing a suitable functional moiety as the leaving group in the platinum(II) complex can effectively induce cell cycle arrest and apoptosis via inhibiting key checkpoint proteins.