YC‐1 induces apoptosis of human renal carcinoma A498 cells in vitro and in vivo through activation of the JNK pathway

Abstract

Background and purpose: The aim of this study was to elucidate the mechanism of YC-1{3-(5 0 -hydroxy methyl-2 0 -furyl)-1-benzylindazole}-induced human renal carcinoma cells apoptosis and to evaluate the potency of YC-1 in models of tumour growth in mice. Experimental approach: YC-1-mediated apoptosis was assessed by analysis of MTT, SRB, DAPI staining and flow cytometry analysis. Knockdown of JNK protein was achieved by transient transfection using siRNA. The mechanisms of action of YC-1 on different signalling pathways involved were studied using western blot. Fas clustering was analysed by confocal microscopy and in vivo efficacy was examined in a A498 xenograft model. Key results: YC-1 displayed cytotoxicity in renal carcinoma cells at 10 À7 -10 À8 M. Increased condensation of chromatin was observed and an increase in the cell population in subG1 phase. Moreover, YC-1 triggered mitochondria-mediated and caspase-dependent pathways. YC-1 significantly induced Fas ligand expression, but did not modify either the protein levels of death receptors or ligands. In addition, Fas clustering in cells responsive to YC-1 was observed, suggesting involvement of a Fas-mediated pathway. Furthermore, YC-1 markedly induced phosphorylation of JNK and a JNK inhibitor, SP600125, and siRNA JNK1/2 significantly reversed YC-1-induced cytotoxicity and protein expression. We suggest that YC-1 induced JNK phosphorylation, the upregulation of FasL and Fas receptor clustering to promote the activation of caspases 8 and 3, resulting in apoptosis. Finally, we demonstrated the antitumour effect of YC-1 in vivo. Conclusions and implications: These data suggest that YC-1 is a good candidate for development as an anticancer drug.

YC-1, a novel potential anticancer agent, inhibit multidrug-resistant protein via cGMP-dependent pathway

“…In HCI-H226 human lung cancer cell line, 2 μM YC-1 arrested cell cycle at G0/G1 phase followed by apoptosis and the suppression of metastasis [43]. Moreover, in A498 human renal carcinoma cells, YC-1 displayed cytotoxicity at 0.3 μM through activation of the JNK pathway [37]. However, in ovarian carcinoma cells, 50 μM YC-1 alone showed weaker toxic effect than 10 μM YC-1 plus camptothecin [44].…”

“…These results suggested that YC-1 may be effective for modulating Pgp activity and enhancing the drug efficacy. Previous studies have reported that YC-1 possessed anticancer effect on human renal carcinoma cells through activation of the JNK pathway and subsequence induced cells accumulation in sub-G1 phase [37]. It has also been demonstrated that YC-1 is a potent inhibitor of hypoxiainducible factor 1alpha (HIF-1alpha) and being developed as an anticancer drug [38].…”

YC‐1 inhibits proliferation of breast cancer cells by down‐regulating EZH2 expression via activation of c‐Cbl and ERK

“…The activation of MAPK-related pathways is required for YC-1 to conduct anticancer activity in cancer cells (Hwang et al, 2003;Wu et al, 2008). Specific inhibitors, PD98059 (MEK inhibitor), SB203580 (p38 MAPK inhibitor), and SP600125 (JNK inhibitor) were used to test the role of MAPKs in EZH2 inhibition.…”

“…Our data demonstrated that YC-1 inhibits EZH2 through a cAMP-or PKA-dependent mechanism. MAPK activation is another important element in YC-1's anticancer activities (Chang et al, 2002;Wu et al, 2008). Previous studies showed that the Raf-ERK pathway mainly affects EZH2 inhibition through gene transcription rather than protein degradation (Fujii et al, 2011).…”

“…YC-1 also exhibits potent anticancer activity via numerous actions in many cancer cell lines (Hsu et al, 2003;Pan et al, 2005;Liu et al, 2006;Lau et al, 2007;Wu et al, 2008;Fallahian et al, 2011;Lee et al, 2011;Cheng et al, 2012). Previous studies demonstrated that YC-1 has anticancer activity in breast cancer cells through a cGMP-dependent pathway (Fallahian et al, 2011;Cheng et al, 2012).…”