NAD(P)H:quinone Oxidoreductase 1 Is Involved in AZ-1-induced Apoptotic Effects in Nasopharyngeal Carcinoma TW01 Cells.

Abstract

Current NPC treatment methods have improved the 5-year survival rates of patients; however, some patients do not benefit from the treatments. Therefore, the existing treatment methods or new drugs must be developed to improve the patient's prognosis. NAD (P)H:quinone oxidoreductase 1 (NQO1), an electron reductase highly expressed in various cancers, can convert aziridinyl-substituted quinone-derived compound into an alkylating agent, resulting in cell apoptosis. Therefore, a di-aziridinyl-substituted quinone-derived compound, AZ-1, was designed previously. The present study investigated whether AZ-1 has anticancer activities in NPC cells and explored the underlying mechanism. NPC-TW01 cells were used in the study, and 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide, colony formation, terminal deoxynucleotidyl transferase dUTP nick end labeling, and immunoblotting assays were performed to assess the cell viability, cell survival, DNA fragmentation, and protein expression, respectively. The results show that AZ-1 significantly inhibited the viability and survival of NPC-TW01 cells. AZ-1 also induced the expression of cleaved PARP, cleaved caspase-8, cleaved caspase-9, and cleaved caspase-3, and triggered DNA fragmentation in NPC-TW01 cells. In addition, AZ-1 induced γH2AX expression, a DNA damage marker, in NPC-TW01 cells. Treatment with dicoumarol, an NQO1 activity inhibitor, not only reversed AZ-1-induced cell viability inhibition but also decreased AZ-1-induced expression of γH2AX, cleaved caspase-8, cleaved caspase-9, and cleaved caspase-3. NQO1 reverses AZ-1-triggered cell viability inhibition, DNA damage, and apoptosis. The findings of this study may provide a basis for the possible clinical application of AZ-1 in the treatment of NPC to improve the prognosis of patients with NPC.