Ursolic acid enhances the antitumor effects of sorafenib associated with Mcl-1-related apoptosis and SLC7A11-dependent ferroptosis in human cancer

TRIM25 promotes temozolomide resistance in glioma by regulating oxidative stress and ferroptotic cell death via the ubiquitination of keap1

Resistance to temozolomide (TMZ) remains an important cause of treatment failure in patients with glioblastoma multiforme (GBM). TRIM25, as a tripartite motif-containing (TRIM) family member, plays a significant role in cancer progression and chemoresistance. However, the function of TRIM25 and its precise mechanism in regulating GBM progression and TMZ resistance remain poorly understood. We found that the expression of TRIM25 was upregulated in GBM, and it was associated with tumor grade and TMZ resistance. Elevated TRIM25 expression predicted a poor prognosis in GBM patients and enhanced tumor growth in vitro and in vivo. Further analysis revealed that elevated TRIM25 expression inhibited oxidative stress and ferroptotic cell death in glioma cells under TMZ treatment. Mechanistically, TRIM25 regulates TMZ resistance by promoting the nuclear import of nuclear factor erythroid 2-related factor 2(Nrf2) via keap1 ubiquitination. Knockdown of Nrf2 abolished the ability of TRIM25 to promote glioma cell survival and TMZ resistance. Our results support the targeting of TRIM25 as a new therapeutic strategy for glioma.

Targeting ABCB6 with nitidine chloride inhibits PI3K/AKT signaling pathway to promote ferroptosis in multiple myeloma

Since multiple myeloma (MM) remains a cureless malignancy of plasma cells to date, it becomes imperative to develop novel drugs and therapeutic targets for MM. We screened a small molecule library comprising 3633 natural product drugs, which demonstrated that Nitidine Chloride (NC), an extract from traditional Chinese medicine Zanthoxylum nitidum. We used Surface Plasmon Resonance-High Performance Liquid Chromatography-Protein Mass Spectrometry (SPR-HPLC-MS), Cellular Thermal Shift Assay (CETSA), molecular docking, and SPR assay to identify the potential targets of NC, in which ABCB6 was the unique target of NC. The effects of ABCB6 on cellular proliferation and drug resistance were determined by CCK8, western blot, flow cytometry, site-mutation cells, transmission electron microscopy, immunohistochemistry staining and xenograft model in vitro and in vivo. NC induced MM cell death by promoting ferroptosis. ABCB6 is the direct target of NC. ABCB6 expression was increased in MM samples compared to normal controls, which was significantly associated with MM relapse and poor outcomes. VGSK was the inferred binding epitope of NC on the ABCB6 protein. In the ABCB6-mutated MM cells, NC did not display cancer resistance, implying the vital role of ABCB6 in NC's bioactivity. Moreover, the silencing of ABCB6 significantly inhibited MM cell growth. Mechanistically, the direct binding of NC to ABCB6 suppressed PI3K/AKT signaling pathway to promote ferroptosis. In conclusion, ABCB6 can be a potential therapeutic target and prognostic biomarker in MM, while NC can be considered a novel drug for MM treatment.

Ferroptosis in gastrointestinal cancer: From mechanisms to implications

Ferroptosis is a form of regulated cell death that is initiated by excessive lipid peroxidation that results in plasma membrane damage and the release of damage-associated molecular patterns. In recent years, ferroptosis has gained significant attention in cancer research due to its unique mechanism compared to other forms of regulated cell death, especially caspase-dependent apoptotic cell death. Gastrointestinal (GI) cancer encompasses malignancies that arise in the digestive tract, including the stomach, intestines, pancreas, colon, liver, rectum, anus, and biliary system. These cancers are a global health concern, with high incidence and mortality rates. Despite advances in medical treatments, drug resistance caused by defects in apoptotic pathways remains a persistent challenge in the management of GI cancer. Hence, exploring the role of ferroptosis in GI cancers may lead to more efficacious treatment strategies. In this review, we provide a comprehensive overview of the core mechanism of ferroptosis and discuss its function, regulation, and implications in the context of GI cancers.

Capparis zeylanica L. root extract promotes apoptosis and cell cycle arrest, inhibits epithelial-to-mesenchymal transition and triggers E-cadherin expression in breast cancer cell lines

Capparis zeylanica L. is a climbing shrub distributed in Indian subcontinent and Mediterranean region. Almost all parts of the plant are used in folk medicine and traditional practices to treat several human ailments. The present study was aimed to investigate the role of C. zeylanica L. root extract in preventing cancerous cells growth and proliferation, as well as promoting apoptosis and cell cycle arrest in MDA-MB-231 and MCF-7 breast cancer cells. Methanolic extract of C. zeylanica L. (MECz) was prepared and characterized by LC-ESI-MS/MS analysis. In vitro cytotoxicity and anti-proliferative activity of MECz was evaluated by MTT assay, while cell viability, apoptosis and cell cycle progression by Muse Cell analyzer. Furthermore, the mRNA and protein expressions of EMT markers were assessed using qRT-PCR and western blotting techniques, respectively. The MECz was found to be rich in phenolic compounds including chlorogenic acid, 6-gingerol, and certain triterpenes like ursolic acid etc. The apparent anti-metastasis activity of MECz was evident from IC50 value of 19.12 and 24.22 μg/mL, respectively, on MDA-MB-231 and MCF-7 cells in MTT assay. An absolute decrease in cell viability (78.1-53.4% and 89.9-49.0%), augmented apoptosis (90.98-48.25% and 88.25-47.70%) and S phase, G2/M phase cell cycle arrest was found by MECz treatment on MDA-MB-231 and MCF-7 cells. The gene expression studies revealed that MECz could significantly (p < 0.001) regulate the expression of EMT markers such as snail, slug, zeb-1, twist-1, fibronectin, vimentin and E-cadherin at molecular level. These findings demonstrate that C. zeylanica L. root extract inhibits breast cancer cells growth and proliferation through regulating the expression of key EMT marker genes and proteins. Thus, MECz may be suggested as a potential anti-metastasis agent in the treatment of breast cancer.

Development of D-α-Tocopherol polyethylene glycol 1000 succinate fabricated nanostructural lipid carrier of sorafenib tosylate for metastatic colorectal targeting application: Stability, physical characterization, cytotoxicity, and apoptotic studies against SW48 cells PTEN

The study aimed to create D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS) nanostructured lipid carriers (NLC) of sorafenib tosylate (ST) as lymphatic delivery systems (LDDS) to fight Metastatic colorectal cancer. Initially, ST-SLN, ST-NLC, and ST-LNE were formulated considering oleic acid (OA), glycerol monolinoleate (GMO), glycerol monolinoleate (GML) as solid lipid and further characterised, and tested for stability. The most stable ST-NLC was fabricated with TPGS to produce ST-TPGS-NLC and evaluated by performing in vitro drug profiling, in vitro cytotoxicity, and apoptotic studies against human female colorectal adenocarcinoma cell lines (SW48 Cells PTEN). Stability studies on three lipidic nanoparticles (ST-SLN, ST-NLC, ST-LEN) showed particle size, polydispersity index, and zeta potential ranging from 165 nm to 298 nm, 0.125 to 0.288, and -31 mV to -16 mV. At 1600 minutes, more than 80% of ST-NLC1 was released, confirming the sustained release pattern of the formulation. ST-NLC and ST-TPGS-NLC have entrapment efficiencies above 50%. Pure ST’s IC50 at 72 hr was 3.45 µg/mL, while 1.56 µg/mL was for ST-TPGS-NLC. The ST-TPGS-NLC reduced the number of livings SW48 Cells PTEN from 91% to 5%, compared to 75% to 8% of pure ST. The ST-TPGS-NLC is a promising LDDS for delivering ST for metastatic colorectal cancer.

System Xc−/GSH/GPX4 axis: An important antioxidant system for the ferroptosis in drug-resistant solid tumor therapy

The activation of ferroptosis is a new effective way to treat drug-resistant solid tumors. Ferroptosis is an iron-mediated form of cell death caused by the accumulation of lipid peroxides. The intracellular imbalance between oxidant and antioxidant due to the abnormal expression of multiple redox active enzymes will promote the produce of reactive oxygen species (ROS). So far, a few pathways and regulators have been discovered to regulate ferroptosis. In particular, the cystine/glutamate antiporter (System Xc−), glutathione peroxidase 4 (GPX4) and glutathione (GSH) (System Xc−/GSH/GPX4 axis) plays a key role in preventing lipid peroxidation-mediated ferroptosis, because of which could be inhibited by blocking System Xc−/GSH/GPX4 axis. This review aims to present the current understanding of the mechanism of ferroptosis based on the System Xc−/GSH/GPX4 axis in the treatment of drug-resistant solid tumors.