Ginsenoside RK3 triggers ferroptosis in osteosarcoma cells and boosts doxorubicin response

A natural compound derived from ginseng may offer a new way to attack osteosarcoma, the most common primary malignant bone tumor in children and adolescents. In a study published in Frontiers in Pharmacology, a research team based in Dalian, China, reports that ginsenoside RK3 suppressed the growth and metastasis of osteosarcoma in laboratory cell models and in mouse xenografts, apparently by pushing tumor cells into ferroptosis, an iron-dependent form of cell death driven by the accumulation of lipid peroxides. When combined with the standard chemotherapy drug doxorubicin, RK3 markedly enhanced tumor suppression compared with either agent alone.

The clinical problem the researchers set out to address is chemoresistance. Conventional osteosarcoma therapies, including doxorubicin, rely on triggering apoptosis, the classical programmed cell death pathway. In recurrent or metastatic disease, tumors commonly develop resistance to these apoptosis-dependent drugs, and the prognosis for affected patients remains poor. Ferroptosis has attracted attention as an alternative lethal mechanism that tumor cells may be unable to evade in the same way, but synthetic ferroptosis inducers have faced limited clinical translation, in part because of poor drug-like properties. This motivated the team to examine whether a plant-derived molecule could activate the pathway instead.

The study was conducted entirely in preclinical models. The researchers tested RK3 on two established human osteosarcoma cell lines, MG63 and U2OS, measuring effects on cell survival and metastatic behavior, and then confirmed the findings in osteosarcoma xenografts implanted in mice. They also monitored the treated animals for systemic toxicity. To probe the underlying mechanism, they combined bioinformatic screening with molecular docking, co-immunoprecipitation experiments and ubiquitination assays, and evaluated the combination of RK3 with doxorubicin both in cell culture and in xenograft-bearing animals.

The mechanistic centerpiece of the work is a signaling axis linking PRMT5, GPX4 and ferroptosis. Molecular docking predicted that RK3 can bind directly to PRMT5, and subsequent experiments showed that RK3 treatment downregulated PRMT5 in the osteosarcoma cells. Because this is a docking prediction rather than a solved crystal structure of the complex, the authors present the binding as a computational hypothesis supported by the downstream functional data.

According to the study, the loss of PRMT5 was associated with a strengthened interaction between GPX4 and FBW7, a substrate-recognition component of the ubiquitin ligase machinery. That enhanced association was accompanied by increased ubiquitination of GPX4, marking the enzyme for proteasomal degradation. As GPX4 protein levels fell, the tumor cells lost their defense against lipid peroxide accumulation and underwent ferroptosis. In the xenograft model, RK3 suppressed tumor growth, and the combination of RK3 with doxorubicin produced greater tumor suppression than doxorubicin monotherapy, supporting the proposed role of the PRMT5/GPX4 axis in sensitizing osteosarcoma to conventional chemotherapy.

The findings position RK3 as a candidate chemosensitizer rather than a replacement for existing treatment. Doxorubicin remains a backbone drug for osteosarcoma, and the study suggests that forcing tumor cells down the ferroptosis pathway may bypass the apoptosis-based resistance mechanisms that undermine conventional therapy in recurrent and metastatic settings. By identifying PRMT5 as the predicted molecular target and GPX4 as the functional effector, the work also adds to a growing body of evidence that the PRMT5/GPX4 axis could serve as a therapeutic target in this disease.

Several important caveats apply. All of the results come from cell lines and mouse xenografts, and no data from human patients are included in the study. The predicted PRMT5 binding has not been confirmed structurally, and the dose, schedule and safety profile of RK3 in humans are unknown. The authors themselves frame the mechanism as a potential one, describing RK3 as inhibiting osteosarcoma possibly through the PRMT5/GPX4 axis. Nevertheless, the study offers a concrete preclinical rationale for combining a ginseng-derived ferroptosis inducer with doxorubicin in osteosarcoma models, and it identifies the PRMT5/GPX4 axis as a potential therapeutic target for chemoresistant disease.

Subject of Research: Ginsenoside RK3 suppresses osteosarcoma via PRMT5/GPX4-ferroptosis axis and enhances doxorubicin chemosensitivity

Article Title: Ginsenoside RK3 suppresses osteosarcoma via PRMT5/GPX4-ferroptosis axis and enhances doxorubicin chemosensitivity

Article References: Xu, Z., Du, Z., Niu, Q., Wang, X., Wang, H., Zhang, M., & Liu, M. (2026). Ginsenoside RK3 suppresses osteosarcoma via PRMT5/GPX4-ferroptosis axis and enhances doxorubicin chemosensitivity. Frontiers in Pharmacology, 17, Article 1980493. https://doi.org/10.3389/fphar.2026.1980493

Image Credits: AI Generated

DOI: 10.3389/fphar.2026.1980493

Keywords: ginsenoside RK3, osteosarcoma, ferroptosis, PRMT5, GPX4, doxorubicin, chemoresistance, FBW7, ubiquitination, lipid peroxidation, xenograft, Frontiers in Pharmacology