Dicoumarol potentiates cisplatin-induced apoptosis mediated by c-Jun N-terminal kinase in p53 wild-type urogenital cancer cell lines

Abstract

3-3 0 -Methylene-bis [4-hydroxycoumarin] (dicoumarol), an inhibitor of NADPH:quinone oxidoreductase 1, has been reported to possess potential antineoplastic effects and the ability to abrogate p53 protein. In the present study, we investigated the cytotoxic effects of dicoumarol in combination with cisplatin (CDDP), using four bladder (RT112, 253J, J82 and UMUC3) and two prostate (LNCap and PC3) cancer cell lines. Single treatment with 100 lM dicoumarol suppressed cell proliferation but did not induce apoptosis at 24 h in all cell lines examined. On the other hand, pretreatment with dicoumarol enhanced cytotoxicity of CDDP in three cell lines with wild type of p53 (RT112, 253J and LNCap), but not in three other cell lines with mutant p53 or in RT112 stable transfectants with a dominant-negative mutant of p53. In RT112 and LNCap, CDDP induced p53 and p21 expression, while pretreatment of dicoumarol suppressed induction of p53/p21 and resulted in sequential activation of c-Jun N-terminal kinase (JNK) in a time-dependent manner. Furthermore, inhibition of JNK, using SP600125, completely suppressed activity of caspases and poly-(ADPribose) polymerase cleavage, leading to suppression of enhancement of CDDP-mediated apoptosis by dicoumarol. These results suggested that dicoumarol could enhance cytotoxicity of CDDP in urogenital cancer cells with wild-type p53 through the p53/p21/JNK pathways.

c-Jun NH2 Terminal Kinase Activation and Decreased Expression of Mitogen-Activated Protein Kinase Phosphatase-1 Play Important Roles in Invasion and Angiogenesis of Urothelial Carcinomas

“…48 -50 In addition, recent reports demonstrated that JNK activation sensitizes cancer cells including urothelial carcinomas to anticancer drug-induced cytotoxicity. 15,37,51 The studies emphasized anti-tumor functions of JNK, which seem to be inconsistent with our present results. There are no critical explanations for this discrepancy, but Igaki and colleagues 52 found that JNK activation switches its proapoptotic effects to survival effects on tumor cells in the presence of oncogenic Ras in Drosophila genetic models.…”

Cancer-specific enhancement of cisplatin-induced cytotoxicity with triptolide through an interaction of inactivated glycogen synthase kinase-3β with p53

“…Among several p53 downstream molecules, p21 has been reported to suppress the activation of JNK (Huang et al, 2003;Watanabe et al, 2006). We established two stable clones of RT112 transfected with p21siRNA vector (RT112 p21siRNA-8 and -12) and investigated JNK status and susceptibility to CDDP and triptolide.…”

“…Cell viability assay and detection of apoptosis Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay as described previously (Watanabe et al, 2006). To detect apoptosis, nuclear staining was performed.…”

“…One of the main reasons can be explained by two distinct functions of p53 in response to DNA damage, one of which is cell-cycle arrest, mainly via p21, and the other is the induction of apoptosis via such genes as PUMA and PIG3. Previously, we demonstrated that dicoumarol, an NADPH quinone oxidoreductase 1 inhibitor, enhanced the cytotoxicity of CDDP through c-Jun N-terminal kinase (JNK) activation by the suppression of the p53-p21 pathway in urogenital cancer cells (Watanabe et al, 2006). These findings indicated that the induction of p53-p21 in malignant cells may possibly suppress the apoptotic process, and inversely, attenuation of p21 expression may make genotoxic chemotherapeutic agents more effective by subverting the normal repair process.…”

JNK implication in adipocyte-like cell death induced by chemotherapeutic drug cisplatin

“…In cases of prostate cancer both pro-and anti-tumor actions of JNK were reported (Leppä and Bohmann, 1999), furthermore, in cooperation with other signaling molecules JNK can regulate the progression of prostate neoplasia to invasive adenocarcinoma (Wagner and Nebreda, 2009;Rodríguez-Berriguete et al, 2012;Hübner et al, 2012). At the same time, increasing evidence indicates that anticancer drug treatment-activated c-Jun-NH 2 -terminal protein kinase mediates cancer cell death caused by a great number of chemotherapeutic agents (Rodríguez-Berriguete et al, 2012;Watanabe et al, 2006). The importance of JNK activation in deciding cell fate in response to cisplatin, one of the most widely used chemotherapeutic agents, was exemplified using various in vitro and in vivo cancer models (Ohtsuka et al, 2003;Watanabe et al, 2006;Brozovic and Osmak, 2007;Shah and Dizon, 2009).…”