Effects of hypoxic preconditioning on neuroblastoma tumour oxygenation and metabolic signature in a chick embryo model

Abstract

Hypoxia episodes and areas in tumours have been associated with metastatic dissemination and poor prognosis. Given the link between tumour tissue oxygen levels and cellular metabolic activity, we hypothesised that the metabolic profile between metastatic and non-metastatic tumours would reveal potential new biomarkers and signalling cues. We have used a previously established chick embryo model for neuroblastoma growth and metastasis, where the metastatic phenotype can be controlled by neuroblastoma cell hypoxic preconditioning (3 days at 1% O2). We measured, with fibre-optic oxygen sensors, the effects of the hypoxic preconditioning on the tumour oxygenation, within tumours formed by SK-N-AS cells on the chorioallantoic membrane (CAM) of chick embryos. We found that the difference between the metastatic and non-metastatic intratumoural oxygen levels was small (0.35% O2), with a mean below 1.5% O2 for most tumours. The metabolomic profiling, using NMR spectroscopy, of neuroblastoma cells cultured in normoxia or hypoxia for 3 days, and of the tumours formed by these cells showed that the effects of hypoxia in vitro did not compare with in vivo tumours. One notable difference was the high levels of the glycolytic end-products triggered by hypoxia in vitro, but not by hypoxia preconditioning in tumours, likely due to the very high basal levels of these metabolites in tumours compared with cells. In conclusion, we have identified high levels of ketones (3-hydroxybutyrate), lactate and phosphocholine in hypoxic preconditioned tumours, all known to fuel tumour growth, and we herein point to the poor relevance of in vitro metabolomic experiments for cancer research.

Portable Oxygen-Sensing Device for the Improved Assessment of Compartment Syndrome and other Hypoxia-Related Conditions

“…Fiber-optic oxygen sensors based on phosphorescence quenching are well described in the scientific literature − and have been evaluated in in vivo models. − However, to date, there is no medical device available for the clinical measurement of intramuscular oxygen. This might be due to the fact that most existing sensors were not designed to measure oxygen under physiological conditions in a clinical setting, require expensive and oversized readout devices, and many of these sensors have also not been evaluated beyond limited in vivo models.…”

“…This might be due to the fact that most existing sensors were not designed to measure oxygen under physiological conditions in a clinical setting, require expensive and oversized readout devices, and many of these sensors have also not been evaluated beyond limited in vivo models. For example, the OXY-MICRO-AOT from World Precision Instruments was evaluated in surgically exposed epididymal fat pads, , whereas the oxygen microsensor from PreSens was evaluated in tumors on the chorioallantoic membrane of chick embryos . Also, intravascular sensors such as the discontinued Paratrend are not directly applicable to an intramuscular oxygen measurement where insertion force is applied to the sensor.…”

Grading of endometrial cancer using 1H HR-MAS NMR-based metabolomics

“…The decreased taurine level in the G3 tumors in comparison to the G1 and G2 ones (Fig. 5 ) could also be associated with the higher hypoxia in the high grade tumors 67 .…”

Pathophysiological Integration of Metabolic Reprogramming in Breast Cancer

“…Additionally, the high level of expression of genes related to ketogenesis has been related to a worse prognosis in breast cancer patients [ 166 ]. However, the involvement of ketone bodies in fueling TCA is somewhat controversial since it has mainly been described in vitro and in some xenografts [ 167 , 168 ]. Paradoxically, the ketogenic diet has been proposed as a cancer treatment [ 169 ].…”