Hypoxia factors suppression effect on the energy metabolism of a malignant melanoma cell SK-MEL-30.

Abstract

Malignant melanoma (MM), as well as other cancers, is a disorder in the cell life cycle at many levels. In terms of energy, the sync of cytosolic and mitochondrial metabolism is required for each cell. Mismatches also caused by hypoxic factors accumulate defects leading to the formation, development and invasiveness of malignant melanoma. Our aim was to compare the effect of HIF-1α and miR-210 on the metabolism of malignant melanoma cells in normoxia and pseudohypoxia. Further, we also investigated how gene silencing affects the viability in order to evaluate the potential of gene therapy in the treatment of MM. We targeted oxidative phosphorylation by genetically suppressing HIF-1α and miR-210. We have examined mitochondrial activity, cytosolic glycolysis and cell viability. The ratio of NADH/NAD+ in the cytoplasm under normal conditions is stable and can thus serve as a specific cellular metabolic marker. Therefore, the study was aimed at finding the cause of the reduction in NADH levels in increasing hypoxia under ideal in vitro conditions on the SK-MEL-30 malignant melanoma cells. The relationship between HIF-1α and miR-210, their effect on transcriptional level, and the subsequent effect on metabolic process attenuation in cells was investigated. Obtained results indicate that the NADH which is accumulated by cells in hypoxia was significantly decreased upon gene silencing. Our studies have shown that small regulatory molecules with organelle-specific effect (such as miRs) need to be targeted, and that the resultant effect is comparable to silencing of "general" hypoxic transcription factors.