A rapid screening system evaluates novel inhibitors of DNA methylation and suggests F-box proteins as potential therapeutic targets for high-risk neuroblastoma.
Target Oncol
; 10(4): 523-33, 2015 Dec.
Article
in En
| MEDLINE
| ID: mdl-25559288
ABSTRACT
After extensive research on radiochemotherapy, 5-year survival rates of children with high risk neuroblastoma still do not exceed 50%, owing to adverse side-effects exemplified by doxorubicin-induced cardiomyopathy. A promising new approach is the combination of conventional therapies with specific modulation of cell signaling pathways promoting therapeutic resistance, such as inhibition of aberrant kinase activity or re-expression of silenced tumor suppressor genes by means of chromatin remodeling. In this regard, we established a system that allows to identify potential drug targets as well as to validate respective candidate inhibitors in high-risk neuroblastoma model cell lines. Cell culture, drug exposure, shRNA-mediated knockdown and phenotype analysis are integrated into an efficient and versatile single well-based protocol. By utilizing this system, we assessed RG108, SGI-1027 and nanaomycin A, three novel DNA methyltransferase inhibitors that have not been tested in neuroblastoma cell lines so far, for their potential of synergistic anti-tumor activity in combination with doxorubicin. We found that, similarly to azacytidine, SGI-1027 and nanaomycin A mediate synergistic growth inhibition with doxorubicin independently of N-Myc status. However, they display high cytotoxicity but lack global DNA demethylation activity. Secondly, we conducted a lentiviral shRNA screen of F-box proteins, key regulators of protein stability, and identified Fbxw11/ß-TrCP2 as well as Fbxo5/Emi1 as potential therapeutic targets in neuroblastoma. These results complement existing studies and underline the reliability and versatility of our single well-based protocol.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
DNA Modification Methylases
/
DNA Methylation
/
F-Box Proteins
/
Enzyme Inhibitors
/
Neuroblastoma
Type of study:
Diagnostic_studies
/
Etiology_studies
/
Guideline
/
Risk_factors_studies
/
Screening_studies
Limits:
Humans
Language:
En
Journal:
Target Oncol
Journal subject:
NEOPLASIAS
Year:
2015
Document type:
Article
Affiliation country: