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Intracranial Orthotopic Allografting of Medulloblastoma Cells in Immunocompromised Mice
Published on: October 3, 2010
Arsenic Trioxide exerts cytotoxic and radiosensitizing effects in pediatric Medulloblastoma cell lines of SHH
Paulo Henrique Dos Santos Klinger1,2, Lara Elis Alberici Delsin3, Gustavo Alencastro Veiga Cruzeiro3
1Department of Pediatrics, University of São Paulo, Ribeirão Preto, Brazil.
Abstract:
We evaluated the potential effects of ATO in different pediatric SHH-MB cell lines (ONS-76: TP53-wild type; DAOY and UW402: TP53-mutated). MB cell lines molecular subgroup was confirmed and TP53 mutations were validated. Cell viability, clonogenicity and apoptosis were evaluated after ATO treatment at different concentrations (1-16 µM) alone or combined with irradiation doses (0.5, 1, 2 and 4 Gy). Rad51 and Ku86 proteins were evaluated by WB. ATO treatment reduced cell viability for all SHH-MB cell lines. Significant decrease of clonogenic capacity and higher apoptosis rates were also observed after ATO exposure, being cell death more pronounced (>70%) for the SHH-MB TP53-mutated. Combined treatment of ATO with irradiation also reduced colonies formation in UW402 tumor cells, which was independent of DNA damage repair proteins Rad51 and Ku86. In silico analyses suggested that a set of genes from cell cycle and p53 pathways are differentially expressed in SHH tumor subtypes, suggesting that cell lines may respond to therapies according to the gene expression profiles. Herein, we showed ATO cytotoxicity in pediatric SHH cell lines, with marked radiosensitizing effect for the MB-SHH TP53-mutated cells. These results highlight the potential of ATO, alone or in combination with radiotherapy, supporting further clinical investigations.
Insights
Arsenic trioxide (ATO) demonstrates significant cytotoxicity in pediatric Sonic Hedgehog-medulloblastoma (SHH-MB) cell lines, particularly those with TP53 mutations. ATO also enhances the radiosensitivity of these aggressive medulloblastoma cells.
Area of Science:
- Pediatric oncology
- Molecular biology
- Cancer therapeutics
Background:
- Medulloblastoma (MB) is a primary brain tumor in children.
- Sonic Hedgehog (SHH) subgroup MB has distinct molecular features and therapeutic challenges.
- TP53 mutations are common in SHH-MB and associated with poorer prognosis.
Purpose of the Study:
- To evaluate the efficacy of arsenic trioxide (ATO) in pediatric SHH-MB cell lines.
- To investigate the combined effect of ATO and radiotherapy.
- To explore the role of TP53 status and gene expression profiles in treatment response.
Main Methods:
- Cultured pediatric SHH-MB cell lines (TP53-wild type and TP53-mutated).
- Assessed cell viability, clonogenicity, and apoptosis following ATO treatment (1-16 µM) alone and combined with irradiation (0.5-4 Gy).
- Evaluated DNA damage repair proteins (Rad51, Ku86) by Western blot; performed in silico gene expression analysis.
Main Results:
- ATO reduced cell viability, clonogenicity, and induced apoptosis in all tested SHH-MB cell lines.
- Cell death was significantly higher (>70%) in TP53-mutated SHH-MB cells.
- Combined ATO and irradiation showed a radiosensitizing effect, independent of Rad51 and Ku86, particularly in TP53-mutated cells.
Conclusions:
- ATO exhibits significant cytotoxicity against pediatric SHH-MB cell lines.
- ATO demonstrates a marked radiosensitizing effect on TP53-mutated SHH-MB cells.
- ATO holds potential as a therapeutic agent, alone or with radiotherapy, warranting further clinical investigation.
