Branched chain amino acid aminotransferase 2 Regulates Ferroptotic Cell Death in Cancer Cells

Abstract

i contribute equally to this manuscript. Conflict of interest statementThe authors have declared that no conflict of interest exists. AbstractFerroptosis has been implicated as a tumor-suppressor function for cancer therapy.Recently the sensitivity to ferroptosis was tightly linked to numerous biological processes, including metabolism of amino acid. Here, using a high-throughput CRISPR/Cas9 based genetic screen in HepG2 cells to search for metabolic proteins inhibiting ferroptosis, we identified branched chain amino acid aminotransferase 2 (BCAT2) as a novel suppressor of ferroptosis. Mechanistically, ferroptosis inducers (erastin, sorafenib and sulfasalazine) activated AMPK/SREBP1 signaling pathway through ferritinophagy, which in turn inhibited BCAT2 transcription. We further confirmed that BCAT2 mediating the metabolism of sulfur amino acid, regulated intracellular glutamate level, whose activation by ectopic expression specifically antagonize system Xc-inhibition and protected liver and pancreatic cancer cells from ferroptosis in vitro and in vivo. Finally, our results demonstrate the synergistic effect of sorafenib and sulfasalazine in downregulating BCAT2 expression and dictating ferroptotic death, where BCAT2 can also be used to predict the responsiveness of cancer cells to ferroptosis-inducing therapies.Collectively, these findings identify a novel role of BCAT2 in ferroptosis, suggesting a potential therapeutic strategy for overcoming sorafenib resistance.

[Retracted] Stearoyl‐CoA Desaturase 1 Potentiates Hypoxic plus Nutrient‐Deprived Pancreatic Cancer Cell Ferroptosis Resistance

“…Lipid Peroxidation Assay. The relative MDA level in cells or tumor issues lysates was measured using a Lipid Peroxidation (MDA) Assay Kit (Abcam, ab118970), and the experiments were carried out as described previously [12]. Cells or tumor tissues were homogenized with lysis buffer and the MDA in samples reacts with thiobarbituric acid (TBA) to generate an MDA-TBA adduct which can be quantified colorimetrically (OD = 532 nm).…”

Regulation of Ferroptosis by Amino Acid Metabolism in Cancer

“…Furthermore, another study also identified BCAT2 as a novel suppressor of ferroptosis, whose activation of ectopic expression could specifically antagonize system Xcinhibition and protect liver cancer and pancreatic cancer cells from ferroptosis. Therefore, BCAT2 could serve to predict the responsiveness of cancer cells to the ferroptosisinducing therapy [104]. Together, reprogramming of BCAA metabolism could change mitochondrial functions as well as gene expression, redraw other metabolic pathways, and change the levels of essential metabolites, including Glu, α-KG, BCAAs and ROS, therefore elevating cancer cell proliferation and enhancing drug resistance capacity [98].…”

Rotenone, an environmental toxin, causes abnormal methylation of the mouse brain organoid's genome and ferroptosis

“…Intracellular ferrous iron level was determined using the iron assay kit (Abcam, ab83366) according to the manufacturer's instructions [38].…”