Abstract | BACKGROUND: HSP90 plays a central role in stabilizing client proteins involved in malignant processes. SNX-2112 is an orally administered potent HSP90 inhibitor that has demonstrated pre-clinical anti- tumor activity in adult malignancies. As many childhood tumors depend upon HSP90 client proteins, we sought to test the pre-clinical efficacy of SNX-2112 in a panel of pediatric cancer cell lines both as a single-agent and in combination with cisplatin (CP). PROCEDURE: Eight cell lines (from osteosarcoma, neuroblastoma, hepatoblastoma, and lymphoma) were studied. Short- and long-term effects of SNX-2112 were assessed by MTT and clonogenic assays. Cell cycling was measured using flow cytometry. Status of HSC70, HSP72, AKT1, C-Raf, and PARP was assessed by immunoblotting. Efficacy of SNX-2112 in combination with CP was assessed using median-effect analysis. RESULTS: Cell lines studied demonstrated sensitivity to SNX-2112 with IC(50) values ranging from 10-100 nM. Low dose treatments (12 nM) resulted in a cytostatic response with a minimal increase in sub-G1 content. A higher dose (70 nM) exhibited a more prolonged inhibition and larger sub-G1 accumulation. Observed levels of AKT1 and C-Raf were markedly reduced over time along with an increase in PARP cleavage. In concurrently administered combination treatments, SNX-2112 and CP synergistically inhibited cell growth. CONCLUSIONS:
SNX-2112 showed marked single-agent activity in pediatric cancer cell lines with downstream effects on HSP90 client proteins. The combination of SNX-2112 and CP showed synergistic activity in two cell lines tested. Further studies of HSP90 inhibitors such as SNX-2112 as a single agent or in combination with chemotherapy are warranted in pediatric cancer.
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Authors | Danielle C Chinn, William S Holland, Janet M Yoon, Theodore Zwerdling, Philip C Mack |
Journal | Pediatric blood & cancer
(Pediatr Blood Cancer)
Vol. 58
Issue 6
Pg. 885-90
(Jun 2012)
ISSN: 1545-5017 [Electronic] United States |
PMID | 21796766
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | Copyright © 2011 Wiley Periodicals, Inc. |
Chemical References |
- Antineoplastic Agents
- HSP90 Heat-Shock Proteins
- Heterocyclic Compounds, 4 or More Rings
- SNX 2112
- Cisplatin
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Topics |
- Antineoplastic Agents
(pharmacology)
- Apoptosis
(drug effects)
- Blotting, Western
- Cell Cycle
(drug effects)
- Cell Line, Tumor
- Cisplatin
(administration & dosage)
- Drug Synergism
- Flow Cytometry
- HSP90 Heat-Shock Proteins
(antagonists & inhibitors)
- Hepatoblastoma
- Heterocyclic Compounds, 4 or More Rings
(pharmacology)
- Humans
- Lymphoma
- Neuroblastoma
- Osteosarcoma
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