Progress in the study of ferroptosis in cancer treatment: State-of-the-Art

Repurposed genipin targeting UCP2 exhibits antitumor activity through inducing ferroptosis in glioblastoma

Uncoupling protein-2 (UCP2) controls the antioxidant response and redox homeostasis in cancer and is considered a potent molecular target for cancer treatment. However, the specific mechanism of UCP2 inhibition and its role in glioblastoma (GBM) have not yet been elucidated. Here, we attempt to identify a UCP2 inhibitor and study the underlying molecular mechanism in GBM. Bioinformatics analysis and immunohistochemistry are used to validate the high expression of UCP2 in GBM and its prognostic significance. Drug intervention and tumor xenograft experiments are conducted to determine the inhibitory effect of genipin, a UCP2 inhibitor, on UCP2. The mitochondrial membrane potential and key ferroptosis genes are examined to determine the occurrence of ferroptosis. High expression of UCP2 in GBM is associated with poor prognosis, and inhibiting UCP2 can alleviate the malignant behavior of GBM tumors. Genipin can downregulate the expression of GPX4 and upregulate the expression of ACSL4 by inhibiting UCP2, leading to ferroptosis and alleviating the malignant behavior of tumors. In summary, UCP2 is a potential therapeutic target for GBM. Genipin, which targets UCP2, effectively inhibits GBM development by inducing ferroptosis in vivo and in vitro. These findings indicate that genipin treatment based on UCP2 targeting has potential therapeutic applications with a clinical perspective for the treatment of GBM patients.

Liposome encapsulated polydopamine nanoparticles: Enhancing ferroptosis and activating hypoxia prodrug activity

The short lifespan of active oxygen species and depressed O2 level during ferroptosis treatment in tumor cells weaken ferroptosis therapy. How to improve the utilization efficiency of active oxygen species generated in real time is pivotal for anticancer treatment. Herein, the tirapazamine (TPZ) loaded polydopamine-Fe nanoparticles (PDA-Fe-TPZ) was modified with unsaturated liposome (Lip), which was constructed to overcome the drawbacks of traditional ferroptosis therapy. The Lip@PDA-Fe-TPZ nanoliposomes can react with H2O2 to produce •OH by Fenton reaction, which then attacks Lip and transforms into radical intermediate (L•) and phospholipid peroxide radical (LOO•) to avoid the annihilation of •OH. The introduced Lip enhances lipid peroxidation and promotes oxygen consumption, resulting in increased hypoxia at tumor site. The introduced TPZ can be triggered by reductase in tumor cells under hypoxia, which can reduce to transient oxidative free radicals by reductase enzymes and destroy the structure of the surrounding biomacromolecules, thus achieving the synergistic treatment of ferroptosis and chemotherapy. In this work, we organically combined enhanced ferrroptosis with hypoxic activated chemotherapy to achieve efficient and specific tumor killing effect, which can sever as a promising treatment of cancer in the future.

A single fluorescent probe to examine the dynamics of mitochondria-lysosome interplay and extracellular vesicle role in ferroptosis

Ferroptosis is a non-apoptotic form of cell death characterized by iron-dependent lipid peroxidation and glutathione (GSH) depletion. Despite recent advances, challenges remain in understanding the bidirectional interactions or interplay between organelles during ferroptosis. In this study, we aimed to understand the interplay between mitochondria (Mito) and lysosomes (Lyso) in cell homeostasis and ferroptosis. For this purpose, we designed a single fluorescent probe that marks GSH in Mito and hypochlorous acid (HOCl) in Lyso with two distinct emissions. Using this dual-targeted single fluorescent probe (9-morphorino pyronine), we detected Mito-Lyso interplay in ferroptosis. We disclosed differences in Mito-Lyso interplay depending on the induction of ferroptosis. Although erastin treatment decreased GSH, RSL3 triggered a HOCl burst, and FIN56- and FINO2-induced ferroptosis increased GSH and HOCl. Additionally, we showed that only extracellular vesicles generated during erastin-induced ferroptosis could spontaneously move and dock to neighboring cells, resulting in accelerated cell death.

Ferroptosis Inducers as Promising Radiosensitizer Agents in Cancer Radiotherapy

Radiotherapy (RT) failure has historically been mostly attributed to radioresistance. Ferroptosis is a type of controlled cell death that depends on iron and is caused by polyunsaturated fatty acid peroxidative damage. Utilizing a ferroptosis inducer may be a successful tactic for preventing tumor growth and radiotherapy-induced cell death. A regulated form of cell death known as ferroptosis is caused by the peroxidation of phospholipids containing polyunsaturated fatty acids in an iron-dependent manner (PUFA-PLs). The ferroptosis pathway has a number of important regulators. By regulating the formation of PUFA-PLs, the important lipid metabolism enzyme ACSL4 promotes ferroptosis, whereas SLC7A11 and (glutathione peroxidase 4) GPX4 prevent ferroptosis. In addition to introducing the ferroptosis inducer chemicals that have recently been demonstrated to have a radiosensitizer effect, this review highlights the function and methods by which ferroptosis contributes to RT-induced cell death and tumor suppression in vitro and in vivo.