Identification of a small molecule as inducer of ferroptosis and apoptosis through ubiquitination of GPX4 in triple negative breast cancer cells

Abstract

Background TNBC is the most aggressive breast cancer with higher recurrence and mortality rate than other types of breast cancer. There is an urgent need for identification of therapeutic agents with unique mode of action for overcoming current challenges in TNBC treatment. Methods Different inhibitors were used to study the cell death manner of DMOCPTL. RNA silencing was used to evaluate the functions of GPX4 in ferroptosis and apoptosis of TNBC cells and functions of EGR1 in apoptosis. Immunohistochemical assay of tissue microarray were used for investigating correlation of GPX4 and EGR1 with TNBC. Computer-aided docking and small molecule probe were used for study the binding of DMOCPTL with GPX4. Results DMOCPTL, a derivative of natural product parthenolide, exhibited about 15-fold improvement comparing to that of the parent compound PTL for TNBC cells. The cell death manner assay showed that the anti-TNBC effect of DMOCPTL mainly by inducing ferroptosis and apoptosis through ubiquitination of GPX4. The probe of DMOCPTL assay indicated that DMOCPTL induced GPX4 ubiquitination by directly binding to GPX4 protein. To the best of our knowledge, this is the first report of inducing ferroptosis through ubiquitination of GPX4. Moreover, the mechanism of GPX4 regulation of apoptosis is still obscure. Here, we firstly reveal that GPX4 regulated mitochondria-mediated apoptosis through regulation of EGR1 in TNBC cells. Compound 13, the prodrug of DMOCPTL, effectively inhibited the growth of breast tumor and prolonged the lifespan of mice in vivo, and no obvious toxicity was observed. Conclusions These findings firstly revealed novel manner to induce ferroptosis through ubiquitination of GPX4 and provided mechanism for GPX4 inducing mitochondria-mediated apoptosis through up-regulation of EGR1 in TNBC cells. Moreover, compound 13 deserves further studies as a lead compound with novel mode of action for ultimate discovery of effective anti-TNBC drug.

An Original Ferroptosis-Related Gene Signature Effectively Predicts the Prognosis and Clinical Status for Colorectal Cancer Patients

“…Ferroptosis is involved in various diseases, such as tissue ischemia, stroke, neurodegeneration, and tumor ( 12 ), which has attracted the attention of many scholars around the world in recent years. It is reported that ferroptosis is involved in several tumors: glioma ( 13 ), breast cancer ( 14 , 15 ), lung cancer ( 15 ), hepatocellular carcinoma ( 16 ), diffuse large B-cell lymphoma ( 17 ), melanoma ( 18 ), and colorectal cancer ( 19 ). Many studies have shown that different types of cancer are vulnerable to ferroptosis.…”

Comprehensive Analysis of Ferroptosis Regulators With Regard to PD-L1 and Immune Infiltration in Clear Cell Renal Cell Carcinoma

“…Ferroptosis is a novel iron-dependent programmed cell death process, which is characteristically distinct from autophagy, apoptosis, and other forms of necrosis (Lei et al, 2020 ). Recently, emerging evidence reported the vital roles of ferroptosis in the tumorigenesis of human malignancies (Ding et al, 2021 ), especially the ccRCC which is intrinsically vulnerable to ferroptosis (Zou et al, 2019 ). However, the potential role of ferroptosis in the ccRCC immune microenvironment remains elusive.…”

Selenoproteins Protect Against Avian Liver Necrosis by Metabolizing Peroxides and Regulating Receptor Interacting Serine Threonine Kinase 1/Receptor Interacting Serine Threonine Kinase 3/Mixed Lineage Kinase Domain-Like and Mitogen-Activated Protein Kinase Signaling

“…Another unique feature of selenoprotein abundance in broilers is that GPX4 protein levels were ∼83-99% lower in the liver of -Se chicks, compared with those of +Se chicks. GPX4 is the only GPX that accepts phospholipid hydroperoxidase as an oxidation substrate in membranes, as well as uses proteinthiol groups as a reduction substrate in the absence of GSH (Ding et al, 2021). Since early embryonic lethality of GPX4knockout mice limits further in vivo studies on the molecular and cellular mechanisms of GPX4, we have speculated that avian GPX4 could function as a redox sensor (Huang et al, 2015).…”