The Effects of Hypoxic Preconditioning on the Oxygenation and Metabolic Profile of Neuroblastoma

Despite neuroblastoma being the most common extracranial solid malignancy in children, it presents a significantly atypical challenge to clinicians and researchers due to its complex biological interplay and heterogeneous behaviour. Hypoxia, which is a lack of oxygenation, has been implicated as a significant factor leading to metastasis, treatment resistance and poor prognosis in many cancers, including neuroblastoma. Whilst our lab has previously demonstrated that hypoxic pre-conditioning of neuroblastoma cells directly triggers neuroblastoma tumour metastasis, it is not known how such preconditioning affects the tumour’s oxygenation itself and how it alters the tumour’s metabolism. We initially measured intratumoural oxygenation, using a fibre-optic oxygen sensor, in tumours originating from neuroblastoma cells and growing on the chorioallantoic membrane (CAM) of a chick embryo model. We investigated the effects of hypoxia preconditioning of the cells on the actual oxygen levels within the tumour. We further investigated, using Nuclear Magnetic Resonance (NMR), the effects of hypoxic preconditioning on the metabolic profile of neuroblastoma tumours. We demonstrated that hypoxic preconditioning had only a minor effect on intratumoural oxygenation values, yet it had a significant measurable influence on the metabolic profile of the tumours. In particular, 13 metabolites showed a consistent response to hypoxia, with 9 being decreased and 4 being increased in the hypoxic sets across cells and tumour, thus illustrating the lasting effects of hypoxic preconditioning on the tumour metabolome