cgp-48664 and Neuroblastoma

cgp-48664 has been researched along with Neuroblastoma* in 2 studies

Other Studies

2 other study(ies) available for cgp-48664 and Neuroblastoma

ArticleYear
Inhibition of S-adenosylmethionine decarboxylase by inhibitor SAM486A connects polyamine metabolism with p53-Mdm2-Akt/protein kinase B regulation and apoptosis in neuroblastoma.
    Molecular cancer therapeutics, 2009, Volume: 8, Issue:7

    S-adenosylmethionine decarboxylase (AdoMetDC) is an essential enzyme of polyamine (PA) biosynthesis, and both AdoMetDC and PA levels are often up-regulated in cancer cells. The second-generation inhibitor SAM486A inhibits AdoMetDC enzyme activity and has been evaluated in phase II clinical cancer trials. However, little is known about the mechanism of action and potential use of this therapeutic drug in the treatment of the pediatric cancer neuroblastoma (NB). Here, we show that p53 wild-type NB cells are highly sensitive to SAM486A treatment. Most notably, SAM486A treatment resulted in the rapid accumulation of proapoptotic proteins p53 and Mdm2. Concomitant with the increase of proteins at endogenous levels, the in vivo phosphorylation of p53 at residues Ser(46)/Ser(392) and Mdm2 at residue Ser(166) was observed. Moreover, the antiapoptotic protein Akt/protein kinase B was down-regulated and also dephosphorylated at residue Ser(473) in a dose- and time-dependent manner and NB cells entered apoptotic cell death. The results presented in this study highlight the importance of PA homeostasis and provide a direct link between PA metabolism and apoptotic cell signaling pathways in p53 wild-type NB cells. PA inhibitors such as SAM486A may be effective alternative agents for the treatment of NBs with or without MYCN amplification.

    Topics: Adenosylmethionine Decarboxylase; Amidines; Antineoplastic Agents; Apoptosis; Blotting, Western; Cell Proliferation; Flow Cytometry; Humans; Indans; Neuroblastoma; Phosphorylation; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-mdm2; S-Adenosylmethionine; Tumor Suppressor Protein p53

2009
Key role for p27Kip1, retinoblastoma protein Rb, and MYCN in polyamine inhibitor-induced G1 cell cycle arrest in MYCN-amplified human neuroblastoma cells.
    Oncogene, 2005, Aug-25, Volume: 24, Issue:36

    Alpha-difluoromethylornithine (DFMO) inhibits the proto-oncogene ornithine decarboxylase (ODC) and is known to induce cell cycle arrest. However, the effect of DFMO on human neuroblastoma (NB) cells and the exact mechanism of DFMO-induced cell death are largely unknown. Treatment with DFMO in combination with SAM486A, an S-adenosylmethionine decarboxylase (AdoMetDC) inhibitor, has been shown to enhance polyamine pool depletion. Therefore, we analysed the mechanism of action of DFMO and/or SAM486A in two established MYCN-amplified human NB cell lines. DFMO and SAM486A caused rapid cell growth inhibition, polyamine depletion, and G1 cell cycle arrest without apoptosis in cell lines LAN-1 and NMB-7. These effects were enhanced with combined inhibitors and largely prevented by cotreatment with exogenous polyamines. The G1 cell cycle arrest was concomitant with an increase in cyclin-dependent kinase inhibitor p27Kip1. In a similar fashion, DFMO and DFMO/SAM486A inhibited the phosphorylation of the G1/S transition-regulating retinoblastoma protein Rb at residues Ser795 and Ser807/811. Moreover, we observed a dramatic decrease in MYCN protein levels. Overexpression of MYCN induces an aggressive NB phenotype with malignant behavior. We show for the first time that DFMO and SAM486A induce G1 cell cycle arrest in NB cells through p27Kip1 and Rb hypophosphorylation.

    Topics: Adenosylmethionine Decarboxylase; Amidines; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cyclin-Dependent Kinase Inhibitor p27; Enzyme Inhibitors; G1 Phase; Gene Expression Regulation, Neoplastic; Humans; Indans; N-Myc Proto-Oncogene Protein; Neuroblastoma; Nuclear Proteins; Oncogene Proteins; Ornithine Decarboxylase; Polyamines; Proto-Oncogene Mas; Retinoblastoma Protein; Tumor Suppressor Proteins

2005