Erastin triggers autophagic death of breast cancer cells by increasing intracellular iron levels

Abstract

Erastin is a small molecular compound that induces ferroptosis by binding to voltage-dependent anion-selective channel protein (VDAC)2, VDAC3 and solute carrier family 7 member 5 inhibiting the cystine/glutamate antiporter. However, to the best of our knowledge, the mechanism of erastin-induced breast cancer cell death remains unclear. In present study aimed to explore the underlying mechanisms of the antitumor effects of erastin on breast cancer cells. Cellular viability was assessed using an MTT assay, a lactate dehydrogenase cytotoxicity assay kit was used to determine the cell death rate, the intracellular Fe 2+ levels were determined using an iron colorimetric assay kit and western blotting was used to estimate the changes of autophagy-associated proteins levels. The present study demonstrated that erastin inhibited the viability of breast cancer cells and induced breast cancer cell death in a dose-dependent manner. Additionally, autophagy was activated by erastin, as demonstrated by upregulated expression levels of autophagy-associated proteins in breast cancer cells. Bafilomycin A1, 3-methyladenine and knockdown of autophagy related (ATG)5 with small interfering RNA prevented erastin-induced breast cancer cell death and inhibited the erastin-induced changes in the expression levels of the autophagy-associated proteins beclin1, ATG5, ATG12, microtubule-associated proteins 1A/1B light chain 3B (LC3B) and P62. Furthermore, erastin-induced breast cancer cell death was inhibited by an iron chelator, deferoxamine, which inhibited the increases of erastin-induced iron levels and inhibited the erastin-induced changes in the expression levels of the autophagy-related proteins beclin1, ATG5, ATG12, LC3B and P62. In summary, erastin triggered autophagic death in breast cancer cells by increasing intracellular iron levels.

Ferroptosis and Its Modulation by Autophagy in Light of the Pathogenesis of Lysosomal Storage Diseases

“…Under conditions of both silencing their expression and lowering iron levels, erastin-induced cell death was not observed. This would suggest an involvement of both autophagy and ferroptosis in cancer cell death [ 47 ]. Thus, one can suggest either a two-way action of ferroptosis activators (which would induce autophagy at the same time) or a feedback linkage between ferroptosis and autophagy (initiated by ferroptosis).…”

Mechanisms of Neoantigen-Targeted Induction of Pyroptosis and Ferroptosis: From Basic Research to Clinical Applications

“…Erastin is a compound that has a strong inhibitory effect on cancers that express the RAS gene, and it can mediate ferroptosis (7). Therefore, developing strategies that can improve the content, solubility and potency of erastin is of great significance for cancer treatment (55)(56)(57). Nanoparticle-induced ferroptosis has also been demonstrated in xenotransplantation studies (58).…”

A narrative review of mechanisms of ferroptosis in cancer: new challenges and opportunities

“…Studies have reported that the voltage-dependent anion channel (VDAC) 2 (VDAC2)/VDAC 3 pathway controls the transmembrane flow of adenosine diphosphate (ADP), phosphatidylinositol (PI), and adenosine triphosphate (ATP) on the mitochondrial outer membrane, and that tubulin can inhibit mitochondrial metabolism by blocking the VDAC2/ VDAC3 pathway, promoting aerobic glycolysis which is the main energy source for tumor cells. Erastin, on the other hand, can induce ferroptosis by inhibiting cystine/ glutamate antiporters by binding to VDAC2, VDAC3, and SLC7A5 (28). Additionally, in a U.S study it was found that the long-chain fatty acyl-CoA synthetase family member 4 (ACSL4), which is related to lipid metabolism, is one of the key proteins in ferroptosis (29).…”