Background/aim: Fucoxanthinol (FxOH), a metabolite of fucoxanthin, is known to inhibit tumorigenicity of human colorectal cancer stem cells (CCSCs) and their sphere formation. Hypoxic conditions and hypoxia-inducible factors (HIFs) are essential to maintain the stemness of CCSCs. We investigated effects of FxOH on sphere formation, intercellular energy metabolites in colonospheres formed from human colorectal HT-29 cells under hypoxic conditions.
Results: FxOH at 50 μM suppressed HIF1α expression and activation of integrin, mitogen-activated protein kinase (MAPK), Wingless/integrated (WNT) and signal transducer and activator of transcription (STAT) signals. Moreover, expression of epithelial-mesenchymal transition- and apoptosis-related proteins in the colonospheres was lowered by FxOH. The level of glycine was reduced in hypoxic colonospheres under FxOH treatment.
Conclusion: FxOH attenuated the sphere formation of hypoxic colonospheres, in part, by suppressing HIF1α expression. Glycine could be a potential predictor for the activity of agents that inhibit sphere formation by hypoxic colonospheres.
Keywords: Fucoxanthinol; colonosphere; colorectal cancer stem cell; hypoxia; metabolite.
Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.