Maintaining iron (Fe) ion and reactive oxygen species homeostasis is essential for cellular function, mitochondrial integrity and the regulation of cell death pathways, and is recognized as a key process underlying the molecular basis of aging and various diseases, such as diabetes, neurodegenerative diseases and cancer. Nutrient-deprivation autophagy factor 1 (NAF-1; also known as CISD2) belongs to a newly discovered class of Fe-sulfur proteins that are localized to the outer mitochondrial membrane and the endoplasmic reticulum. It has been implicated in regulating homeostasis of Fe ions, as well as the activation of autophagy through interaction with BCL-2. Here we show that small hairpin (sh) RNA-mediated suppression of NAF-1 results in the activation of apoptosis in epithelial breast cancer cells and xenograft tumors. Suppression of NAF-1 resulted in increased uptake of Fe ions into cells, a metabolic shift that rendered cells more susceptible to a glycolysis inhibitor, and the activation of cellular stress pathways that are associated with HIF1a. Our studies suggest that NAF-1 is a major player in the metabolic regulation of breast cancer cells through its effects on cellular Fe ion distribution, mitochondrial metabolism and the induction of apoptosis.
Bibliographical noteFunding Information:
This work was supported by the Israel Science Foundation [grant number ISF 865/ 13 to R.N.]; funds from the University of North Texas College of Arts and Sciences awarded to R.M. and R.K.A. Work at the Center for Theoretical Biological Physics was sponsored by the National Science Foundation [grants number PHY-1427654 and MCB-1214457]. The funders had no role in the design, data collection, analysis, decision to publish or preparation of the manuscript. Deposited in PMC for immediate release.
- NEET proteins