Abstract C189: Active compound isolated from human urine induced differentiation and apoptosis in K562 chronic myelogenous leukemia cells and enhanced the effects of imatinib

Abstract

Leukemia is a serious disease that affects both children and adults. Although all-trans retinoic acid (ATRA) and targeted drug such as imatinib could effectively treat acute promyelocytic (APL) and chronic myelogenous leukemia (CML), respectively, rare therapeutics is available when drug resistance or recurrence occurred. Searching for alternative agent for refractory patient is urgently needed. Our previous studies had found that a human urine extract CDA-2 could induce differentiation of HL60 APL cells as well as potentiate the effects of ATRA and imatinib on HL60 and K562 CML cells, respectively. Purification of active compound possessing these anti-leukemic effects from CDA-2 was thus performed. Recently, an active compound named as P18.9 was isolated. It induced differentiation of K562 CML cells as evidenced by the nitroblue-tetrazolium (NBT) reduction test. At higher dose, flow cytometry analysis showed that P18.9 induced sub-G1 apoptotic fraction of K562 cells and enhanced the sub-G1 fraction induced by imatinib at a scale of about two folds. Although P18.9 did not induce differentiation of HL60 APL cells, it substantially enhanced the ATRA-induced differentiation. This is the first study to isolate an active compound from human urine, which exerts anti-leukemic effects alone or cooperatively with clinical used drugs. The chemical structure of P18.9 had been identified and further subsequent structure modification is ongoing. Continuing the effort to develop P18.9 and its derivatives as novel therapeutics for refractory APL or CML patients is warranted. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C189.