Inhibiting JNK Dephosphorylation and Induction of Apoptosis by Novel Anticancer Agent NSC-741909 in Cancer Cells

Department of Thoracic and Cardiovascular Surgery, University of Texas M D Anderson Cancer Center, Houston, Texas 77030, USA.
Journal of Biological Chemistry (Impact Factor: 4.57). 06/2009; 284(25):16948-55. DOI: 10.1074/jbc.M109.010256
Source: PubMed


NSC-741909 is a recently identified novel anticancer agent that suppresses the growth of several NCI-60 cancer cell lines with a unique anticancer spectrum. However, its molecular mechanisms remain unknown. To determine the molecular mechanisms of NSC-741909-induced antitumor activity, we analyzed the changes of 77 protein biomarkers in a sensitive lung cancer cell line after treatment with this compound by using reverse-phase protein microarray. The results showed that phosphorylation of mitogen-activated protein (MAP) kinases (P38 MAPK, ERK, and JNK) were persistently elevated by the treatment with NSC-741909. However, only the JNK-specific inhibitor SP600125 effectively blocked the apoptosis induced by NSC-741909. Moreover, NSC-741909-mediated apoptosis was also blocked by a dominant-negative JNK construct, suggesting that sustained activation of JNK is critical for the apoptosis induction. Further studies revealed that treatment with NSC-741909 suppressed dephosphorylation of JNK and the expression of MAPK phosphatase-1. Thus, NSC-741909-mediated inhibition of JNK dephosphorylation results in sustained JNK activation, which leads to apoptosis in cancer cells.

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    • "A few of them were found to be more active than oncrasin-1 in sensitive cancer cells and were further evaluated for their anticancer activities in NCI-60 cancer cell line panel. One of these, NSC-741909 (1-[(4-chlorophenyl) methyl]-1H-indole-3-methanol, oncrasin-60), was found to suppress the growth of several NCI-60 cancer cell lines with a unique anticancer spectrum [7]. Mechanistic studies by reverse-phase protein microarray (RPPA) revealed that treatment with NSC-741909 led to sustained elevation of MAP kinase (P38 MAPK, ERK, and JNK) phosphorylation by suppressing their dephosphorylation. "
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    ABSTRACT: To optimize the antitumor activity of oncrasin-1, a small molecule identified through synthetic lethality screening on isogenic K-Ras mutant tumor cells, we developed several analogues and determined their antitumor activities. Here we investigated in vitro and in vivo antitumor activity of NSC-743380 (1-[(3-chlorophenyl) methyl]-1H-indole-3-methanol, oncrasin-72), one of most potent analogues of oncrasin-1. In vitro antitumor activity was determined in NCI-60 cancer cell line panel using cell viability assay. In vivo antitumor activity was determined in parallel with NSC-741909 (oncrasin-60) in xenograft tumors established in nude mice from A498, a human renal cancer cell line. Changes in gene expression levels and signaling pathway activities upon treatment with NSC-743380 were analyzed in breast and renal cancer cells by Western blot analysis. Apoptosis was demonstrated by Western blot analysis and flow cytometric analysis. NSC-743380 is highly active against a subset of cancer cell lines derived from human lung, colon, ovary, kidney, and breast cancers. The 50% growth-inhibitory concentration (GI(50)) for eight of the most sensitive cell lines was ≤ 10 nM. In vivo study showed that NSC-743380 has a better safety profile and greater antitumor activity than NSC-741909. Treatment with NSC-743380 caused complete regression of A498 xenograft tumors in nude mice at the tested doses ranging from 67 mg/kg to 150 mg/kg. Mechanistic characterization revealed that NSC-743380 suppressed the phosphorylation of C-terminal domain of RNA polymerase II, induced JNK activation, inhibited JAK2/STAT3 phosphorylation and suppressed cyclin D1 expression in sensitive human cancer cells. Blocking JNK activation or overexpression of constitutively active STAT3 partially blocked NSC-743380-induced antitumor activity. NSC-743380 induces antitumor activity through modulation of functions in multiple cancer related pathways and could be a potential anticancer agent for some solid tumors.
    PLoS ONE 12/2011; 6(12):e28487. DOI:10.1371/journal.pone.0028487 · 3.23 Impact Factor
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    • "NSC-741909 is an analogue of oncrasin-1 which we identified as an anticancer agent through cell-based synthetic lethality screening (Guo et al. 2008). Testing of NCI-60 cell lines showed that NSC-741909 has a unique anticancer spectrum and is effective against a number of cancer cell lines derived from lung, colon, ovarian, kidney and breast cancers, suggesting its novel mechanisms (Wei et al.2009). Molecular characterization of NSC-741909 revealed that NSC-741909-induced activation of MAPK (including p38, JNK, and ERK) in sensitive cells and that suppression of MAPK dephosphorylation could be the primary cause of MAPK activation. "
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    ABSTRACT: NSC-741909 (1-[(4-chlorophenyl)methyl]-1H-Indole-3-methanol) is a novel anticancer agent that is highly active against several NCI-60 cancer cell lines. This agent induces sustained activation of mitogen-activated protein kinases (MAPK), including JNK and p38 MAP kinases. However, the mechanisms of its selective antitumor activity in some cancer cell lines remain unknown. We tested the combined effects of NSC-741909 and several kinase inhibitors that target the Raf/MEK/ERK1/2 or PI3K/AKT pathways in two sensitive lung cancer cells. We found that PD98059 (2'-amino-3'-methoxyflavone), a flavone derivative and a selective MEK inhibitor, can dramatically block the cell killing effect of NSC-741909. To determine whether this inhibitory effect is associated with MEK inhibition or other mechanisms, we evaluated the effects of other MEK inhibitors with different chemical structures and flavone derivatives that do not have an effect on MEK. We found that several flavonoids can markedly block NSC-741909-induced apoptosis and JNK activation in a time-dependent manner, regardless of whether they inhibit MEK or not. In contrast, NSC-741909-induced JNK activation and apoptosis were not blocked by other MEK-specific inhibitors U0126 and CI1040. Our results also showed that NSC-741909 induced a dramatic increase of reactive oxygen species in sensitive cells and that flavonoids effectively blocked the NSC-741909-induced reactive oxygen species production which are associated with flavonoids' antagonistic effects on NSC-741909-induced JNK activation and apoptosis. Those results demonstrated that flavonoids-mediated antagonist effect is through scavenging of reactive oxygen species. Our results may have implication on the design of clinical evaluation of antitumor activity of NSC-741909 or its analogues.
    European journal of pharmacology 12/2010; 649(1-3):51-8. DOI:10.1016/j.ejphar.2010.08.057 · 2.53 Impact Factor
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    • "NSC-741909 is one of the oncrasin-1 analogues that was highly active against several cell lines derived from lung, colon, breast, ovarian, and kidney cancers when tested in NCI-60 cancer cell lines by the Developmental Therapeutics Program at the National Cancer Institute. Using a reverse-phase protein microarray assay, we determined molecular changes in 77 protein biomarkers in an oncrasin-sensitive lung cancer cell line after treatment with NSC-741909 [2]. These results showed that treatment with NSC-741909 induced persistent activation of mitogen-activated protein kinases (MAPKs), including p38 MAPK, Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK), and that persistent JNK activation is associated with apoptosis induction by this compound [2]. "
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    ABSTRACT: NSC-741909 is a novel anticancer agent that can effectively suppress the growth of several cell lines derived from lung, colon, breast, ovarian, and kidney cancers. We recently showed that NSC-741909-induced antitumor activity is associated with sustained Jun N-terminal kinase (JNK) activation, resulting from suppression of JNK dephosphorylation associated with decreased protein levels of MAPK phosphatase-1. However, the mechanisms of NSC-741909-induced antitumor activity remain unclear. Because JNK is frequently activated by oxidative stress in cells, we hypothesized that reactive oxygen species (ROS) may be involved in the suppression of JNK dephosphorylation and the cytotoxicity of NSC-741909. The generation of ROS was measured by using the cell-permeable nonfluorescent compound H2DCF-DA and flow cytometry analysis. Cell viability was determined by sulforhodamine B assay. Western blot analysis, immunofluorescent staining and flow cytometry assays were used to determine apoptosis and molecular changes induced by NSC-741909. Treatment with NSC-741909 induced robust ROS generation and marked MAPK phosphatase-1 and -7 clustering in NSC-741909-sensitive, but not resistant cell lines, in a dose- and time-dependent manner. The generation of ROS was detectable as early as 30 min and ROS levels were as high as 6- to 8-fold above basal levels after treatment. Moreover, the NSC-741909-induced ROS generation could be blocked by pretreatment with antioxidants, such as nordihydroguaiaretic acid, aesculetin, baicalein, and caffeic acid, which in turn, inhibited the NSC-741909-induced JNK activation and apoptosis. Our results demonstrate that the increased ROS production was associated with NSC-741909-induced antitumor activity and that ROS generation and subsequent JNK activation is one of the primary mechanisms of NSC-741909-mediated antitumor cell activity.
    Journal of Translational Medicine 04/2010; 8(1):37. DOI:10.1186/1479-5876-8-37 · 3.93 Impact Factor
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