| Title | Inhibition of IGF-I Receptor Signaling in Combination with Rapamycin or Temsirolimus Increases MYC-N Phosphorylation. | | Author(s) | Coulter DW, Wilkie MB, Moats-Staats BM | | Institution | Division of Hematology-Oncology, Department of Pediatrics, 982165 Nebraska Medical Center, Omaha, NE 68198-2165, U.S.A. dcoulter@chsomaha.org. | | Source | Anticancer Res 2009 Jun; 29(6):1943-9. | | Abstract | BACKGROUND: It has been previously shown that blockade of the type 1 insulin-like growth factor receptor (IGF1R) signaling combined with mTOR inhibition decreased neuroblastoma proliferation in vitro. MYC-N inactivation occurs through phosphorylation by downstream elements of the IGF1R signaling pathway. It was hypothesized that inhibition of IGF1R signaling would increase the inactivation of MYC-N.
MATERIALS AND METHODS: BE-2(c) and IMR-32 neuroblastoma cell lines were treated with varying concentrations of alphaIR3, rapamycin and temsirolimus either alone or in combination and the expression of MYC-N and phosphorylated MYC-N proteins were evaluated by Western blotting. The number of apoptotic cells was evaluated through cleaved caspase-3 expression.
RESULTS: IGF1R signaling blockade in combination with mTOR inhibition decreased MYC-N protein expression, increased MYC-N phosphorylation and significantly increased cleaved caspase-3 expression in treated cells.
CONCLUSION: The combination of rapamycin or temsirolimus with alphaIR3 decreases MYC-N expression, increases MYC-N phosphorylation and induces apoptosis in vitro which may have clinical relevance to children with neuroblastoma. | | Language | eng | | Pub Type(s) | Journal Article
| | PubMed ID | 19528451 |
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