Dysregulation of retinoic acid signaling is implicated in several human cancer types, including melanoma where the gene encoding retinoic acid receptor beta (RARβ) is frequently silenced by promoter hypermethylation. In this chapter, we describe some of the experimental procedures that we have used to characterize the role of RARβ signaling on the regulation of cellular metabolism in melanoma. Central to these studies is the use of the Seahorse XF Analyzer, which allows real-time assessment of the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in cultured cells as readouts for oxidative phosphorylation and glycolysis, respectively. The levels of RARβ signaling can be modulated using RARβ agonists (e.g., all-trans retinoic acid) and antagonists (e.g., LE135). The bioenergetic profiles of melanoma cells in response to RARβ modulators and other metabolic modifiers can be the basis for defining new therapeutic strategies.
Keywords: Cancer metabolism; Extracellular acidification rate; Glycolytic activity; Melanoma; Metabolic profile; Mitochondrial function; Oxygen consumption rate; Retinoic acid receptor β; Seahorse XF Analyzer; Warburg effect.