LRP1-Mediated Endocytosis May Be the Main Reason for the Difference in Cytotoxicity of Curcin and Curcin C on U2OS Osteosarcoma Cells

Artesunate induces ferroptosis in osteosarcoma through NCOA4-mediated ferritinophagy

Osteosarcoma (OS) is a prevalent primary malignant bone tumor that lacks effective therapeutic interventions. Artesunate (ART) has been proved to have remarkable treatment effects on severe malaria and anti-tumor properties. This study aimed to investigate the anti-OS effects and underlying mechanisms of ART. The potential mechanisms of ART-mediated anti-OS activity were analyzed by using RNA sequencing, iron accumulation, lipid peroxidation, western blotting, and small interfering RNA (siRNA) transfection. In vivo, a xenograft mice model was adopted to explore the anticancer effect of ART. The present study revealed that ART significantly suppressed OS cell proliferation. Subsequent results suggested that ART exerted anti-OS activity mainly through the ferroptosis pathway. ART decreased the GSH/GSSG ratio, xCT and GPX4 expression, while increasing MDA and lipid peroxidation, which were reversed by Fer-1, DFO, 3-MA, and NCOA4 silencing. Mechanistically, ART upregulated the expression of TFR and DMT1, and triggered ferritinophagy by upregulating the expression of NCOA4, which increased Fe2+ accumulation and triggered ferroptosis. In addition, cytoplasmic iron further activated Mfrn2-mediated transportation of cytoplasmic free iron into the mitochondria, resulting in mitochondrial iron overload, eventually leading to lipid peroxidation and ferroptosis. Furthermore, in an OS xenograft mouse model, administration of ART inhibited tumor growth by ferroptosis. Collectively, our findings indicated that ART has the potential anti-OS capacity through NCOA4-mediated ferritinophagy, which might shed light on the future of OS therapy.

Antifungal Activity of Ribosome-Inactivating Proteins

The control of crop diseases caused by fungi remains a major problem and there is a need to find effective fungicides that are environmentally friendly. Plants are an excellent source for this purpose because they have developed defense mechanisms to cope with fungal infections. Among the plant proteins that play a role in defense are ribosome-inactivating proteins (RIPs), enzymes obtained mainly from angiosperms that, in addition to inactivating ribosomes, have been studied as antiviral, fungicidal, and insecticidal proteins. In this review, we summarize and discuss the potential use of RIPs (and other proteins with similar activity) as antifungal agents, with special emphasis on RIP/fungus specificity, possible mechanisms of antifungal action, and the use of RIP genes to obtain fungus-resistant transgenic plants. It also highlights the fact that these proteins also have antiviral and insecticidal activity, which makes them very versatile tools for crop protection.

Biological Activities of Ribosome-Inactivating Proteins

After more than 50 years of research, studies on the structure and biological activities of ribosome-inactivating proteins (RIPs) continue to provide a field of great interest within the scientific community, both for the health risks they pose and their applications in medicine and biotechnology [...].