Involvement of ferroptosis in eribulin-induced cytotoxicity in ovarian clear cell carcinoma

Shikonin promotes ferroptosis though NSUN2-mediated m5C methylation modification of TFRC in acute myelocytic leukemia

Shikonin (SHK), extracted from the traditional Chinese herb Lithospermum erythrorhizon, demonstrates a wide range of pharmacological activities. This study aimed to explore the role and underlying mechanisms of the 5-methylcytosine (m5C) RNA methyltransferase NOL1/NOP2/SUN domain (NSUN)2 in acute myelocytic leukemia (AML). To assess cell viability and death, we employed Cell Counting Kit-8 and propidium iodide staining. Ferroptosis-related markers were evaluated using commercial kits and Western blot analysis. The m5C levels of ferroptosis-associated mRNAs were quantified by methylated RNA immunoprecipitation (MeRIP)-qPCR. The specific m5C sites on the transferrin receptor (TFRC) mRNA were identified through a dual-luciferase reporter assay, while the interaction between NSUN2 and TFRC was investigated using RNA immunoprecipitation (RIP). The role of SHK in vivo was explored using a xenografted tumor model. Our findings revealed that SHK significantly reduced cell viability and induced cell death and ferroptosis in HL-60 and NB4 cells. Notably, SHK treatment led to an upregulation of NSUN2 expression. Inhibition of NSUN2 reversed the effects of SHK, restoring cell viability and reducing cell death and ferroptosis. Mechanistically, NSUN2 enhanced TFRC expression via m5C-dependent methylation. Overexpression of NSUN2 similarly decreased cell viability and increased cell death and ferroptosis, effects that were mitigated upon silencing of TFRC. In vivo, SHK treatment effectively suppressed tumor growth in xenografted mice. In summary, our study demonstrated that SHK promoted cell death and ferroptosis in AML by modulating NSUN2-mediated m5C methylation of TFRC. These findings provided novel insights into potential therapeutic strategies for AML.

Eribulin exerts multitarget antineoplastic activity in glioma cells

BACKGROUND

Gliomas, particularly glioblastomas, are highly aggressive cancers with rapid proliferation and poor prognosis. Current treatments have limited efficacy, highlighting the need for new therapeutic strategies. Eribulin mesylate, a synthetic macrocyclic ketone, has shown potential as an anticancer agent in several malignancies. This study investigates the cellular and molecular effects of eribulin in glioma models, focusing on its impact on cell cycle progression, apoptosis, mitochondrial function, and migration.

METHODS

Glioma cell lines were treated with eribulin. Cell viability was measured by MTT assay, and the cell cycle was analyzed by flow cytometry. Apoptosis was assessed through morphological changes, PARP1 cleavage, and γH2AX expression. Mitochondrial integrity and reactive oxygen species levels were evaluated by flow cytometry. Cell migration was assessed using a spheroid-based assay, and protein expression changes were analyzed by Western blotting.

RESULTS

Eribulin reduced cell viability, with HOG cells exhibiting the highest sensitivity. Cell cycle analysis showed G2/M phase arrest and morphological examination revealed polyploidy and apoptotic features. Mitochondrial dysfunction was observed, with decreased mitochondrial membrane potential and increased reactive oxygen species, particularly in HOG and T98G cells. Molecular analysis indicated activation of apoptotic pathways (PARP1 cleavage and γH2AX elevation) and reduced stathmin 1 expression. Eribulin also significantly reduced cell migration in HOG cells.

CONCLUSION

Eribulin demonstrates potent anti-glioma effects through apoptosis, mitochondrial dysfunction, and cell cycle disruption. These findings support its potential as a therapeutic option for glioblastoma treatment, warranting further investigation into its mechanisms and clinical applicability.

ML210 Antagonizes ABCB1- Not ABCG2-Mediated Multidrug Resistance in Colorectal Cancer

Objectives: ABCB1-mediated multidrug resistance (MDR) compromises chemotherapy efficacy in colorectal cancer (CRC). Despite decades of research, no selective ABCB1 inhibitor has achieved clinical success. This study investigates ML210 as a novel ABCB1-specific inhibitor to reverse ABCB1-driven MDR. Methods: Cytotoxicity assays (MTT) were performed on ABCB1-overexpressing HCT-8/V and ABCG2-overexpressing S1-M1-80 CRC cells. Drug accumulation (doxorubicin/mitoxantrone) was quantified via flow cytometry, and cell cycle effects were analyzed using propidium iodide staining. Molecular docking utilized the ABCB1 crystal structure. Results: ML210 selectively reversed ABCB1-mediated resistance to doxorubicin and vincristine in HCT-8/V cells, enhancing intracellular drug accumulation without affecting ABCG2 activity. It induced cell cycle arrest in ABCB1-overexpressing cells and did not alter ABCB1 protein expression. Molecular docking revealed stable binding of ML210 within the ABCB1 substrate pocket through hydrophobic interactions and hydrogen bonding. Conclusions: ML210 is a selective ABCB1 inhibitor that circumvents MDR via direct transport blockade, offering a targeted strategy against ABCB1-mediated chemoresistance in CRC. Its specificity for ABCB1 over ABCG2 highlights potential clinical advantages.

Redox-Regulated Iron Metabolism and Ferroptosis in Ovarian Cancer: Molecular Insights and Therapeutic Opportunities

Ovarian cancer (OC), known for its lethality and resistance to chemotherapy, is closely associated with iron metabolism and ferroptosis-an iron-dependent cell death process, distinct from both autophagy and apoptosis. Emerging evidence suggests that dysregulation of iron metabolism could play a crucial role in OC by inducing an imbalance in the redox system, which leads to ferroptosis, offering a novel therapeutic approach. This review examines how disruptions in iron metabolism, which affect redox balance, impact OC progression, focusing on its essential cellular functions and potential as a therapeutic target. It highlights the molecular interplay, including the role of non-coding RNAs (ncRNAs), between iron metabolism and ferroptosis, and explores their interactions with key immune cells such as macrophages and T cells, as well as inflammation within the tumor microenvironment. The review also discusses how glycolysis-related iron metabolism influences ferroptosis via reactive oxygen species. Targeting these pathways, especially through agents that modulate iron metabolism and ferroptosis, presents promising therapeutic prospects. The review emphasizes the need for deeper insights into iron metabolism and ferroptosis within the redox-regulated system to enhance OC therapy and advocates for continued research into these mechanisms as potential strategies to combat OC.