PRIMA-1(MET)-induced neuroblastoma cell death is modulated by p53 and mycn through glutathione level

BACKGROUND: Neuroblastoma is the most common extracranial solid tumor in children. This cancer has a low frequency of TP53 mutations and its downstream pathway is usually intact. This study assessed the efficacy of the p53 activator, PRIMA-1(MET), in inducing neuroblastoma cell death. METHODS: CellTiter 2.0 was used to study susceptibility and specificity of NB cell lines to PRIMA-1(MET). Real-time PCR and western blot were used to assess the most common p53 transactivation targets. Induction of p53 and Noxa, and inhibition of Cas3/7, were used to assess impact on cell death after PRIMA-1(MET) treatment. Flow cytometry was used to analyze cell cycle phase and induction of apoptosis, reactive oxygen species, and the collapse of mitochondrial membrane potential. RESULTS: Neuroblastoma cell lines were at least four times more susceptible to PRIMA-1(MET) than were primary fibroblasts and keratinocyte cell lines. PRIMA-1(MET) induced cell death rapidly and in all cell cycle phases. Although PRIMA-1(MET) activated p53 transactivation activity, p53’s role is likely limited because its main targets remained unaffected, whereas pan-caspase inhibitor demonstrated no ability to prevent cell death. PRIMA-1(MET) induced oxidative stress and modulated the methionine/cysteine/glutathione axis. Variations of MYCN and p53 modulated intracellular levels of GSH and resulted in increased/decreased sensitivity of PRIMA-1(MET). PRIMA-1(MET) inhibited thioredoxin reductase, but the effect of PRIMA-1(MET) was not altered by thioredoxin inhibition. CONCLUSIONS: PRIMA-1(MET) could be a promising new agent to treat neuroblastoma because it demonstrated good anti-tumor action. Although p53 is involved in PRIMA-1(MET)-mediated cell death, our results suggest that direct interaction with p53 has a limited role in neuroblastoma but rather acts through modulation of GSH levels. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13046-019-1066-6) contains supplementary material, which is available to authorized users.