Metabolic reprogramming orchestrates cancer stem cell properties in nasopharyngeal carcinoma.

Cancer stem cells (CSCs) represent a subpopulation of tumor cells endowed with self-renewal capacity and are considered as an underlying cause of tumor recurrence and metastasis. The metabolic signatures of CSCs and the mechanisms involved in the regulation of their stem cell-like properties still remain elusive. We utilized nasopharyngeal carcinoma (NPC) CSCs as a model to dissect their metabolic signatures and found that CSCs underwent metabolic shift and mitochondrial resetting distinguished from their differentiated counterparts. In metabolic shift, CSCs showed a greater reliance on glycolysis for energy supply compared with the parental cells. In mitochondrial resetting, the quantity and function of mitochondria of CSCs were modulated by the biogenesis of the organelles, and the round-shaped mitochondria were distributed in a peri-nuclear manner similar to those seen in the stem cells. In addition, we blocked the glycolytic pathway, increased the ROS levels, and depolarized mitochondrial membranes of CSCs, respectively, and examined the effects of these metabolic factors on CSC properties. Intriguingly, the properties of CSCs were curbed when we redirected the quintessential metabolic reprogramming, which indicates that the plasticity of energy metabolism regulated the balance between acquisition and loss of the stemness status. Taken together, we suggest that metabolic reprogramming is critical for CSCs to sustain self-renewal, deter from differentiation and enhance the antioxidant defense mechanism. Characterization of metabolic reprogramming governing CSC properties is paramount to the design of novel therapeutic strategies through metabolic intervention of CSCs.

Resveratrol Impedes the Stemness, Epithelial-Mesenchymal Transition, and Metabolic Reprogramming of Cancer Stem Cells in Nasopharyngeal Carcinoma through p53 Activation.

Cancer stem cells (CSCs) are able to self-renew and are refractory to cancer treatment. To investigate the effects of resveratrol on CSCs of nasopharyngeal carcinoma (NPC), we employed a behavior selection strategy to isolate CSCs based on radioresistance, chemoresistance, and tumor sphere formation ability. These NPC CSCs displayed stem cell properties and underwent metabolic shift to predominately rely on glycolysis for energy supply. Intriguingly, we found that resveratrol turned off the metabolic switch, increased the reactive oxygen species (ROS) level, and depolarized mitochondrial membranes. These alterations in metabolism occurred concomitantly with the suppression of CSC properties including resistance to therapy, self-renewal capacity, tumor initiation capacity, and metastatic potential in NPC CSCs. We found that resveratrol impeded CSC properties through the activation of p53 and this effect could be reversed by knockdown of p53. Furthermore, resveratrol suppressed the stemness and EMT through reactivating p53 and inducing miR-145 and miR-200c, which were downregulated in NPC CSCs. In conclusion, we demonstrated that resveratrol employed the p53 pathway in regulating stemness, EMT, and metabolic reprogramming. Further investigation of the molecular mechanism of p53 activation by resveratrol may provide useful information for the development of novel therapies for cancer treatment through targeting to CSCs.