PRMT5-mediated arginine methylation stabilizes GPX4 to suppress ferroptosis in cancer

Cell Biology Biochemistry Oncology Life Sciences Medicine
ferroptosis PRMT5 GPX4 cancer therapy methylation tumor progression antioxidant

Background Introduction

Ferroptosis is a form of cell death triggered by iron-dependent lipid peroxidation, which has recently been recognized as having significant potential in cancer therapy. Cancer cells evade ferroptosis through various molecular alterations and metabolic reprogramming mechanisms, with glutathione peroxidase 4 (GPX4) being a key regulator of ferroptosis. GPX4 inhibits ferroptosis by converting toxic lipid peroxides into non-toxic lipid alcohols, thereby preventing lipid peroxidation. However, the stability of GPX4 and its regulatory mechanisms in cancer cells remain incompletely understood.

This study aims to reveal how cancer cells enhance the stability of GPX4 through PRMT5 (protein arginine methyltransferase 5)-mediated methylation, thereby resisting ferroptosis. This discovery not only helps to understand how cancer cells evade ferroptosis through metabolic reprogramming but also provides potential targets for developing new cancer treatment strategies.

Source of the Paper

This paper was co-authored by Yizeng Fan, Yuzhao Wang, Weichao Dan, and others from multiple research institutions, with key authors including researchers from Harvard Medical School, MD Anderson Cancer Center, and other institutions. The paper was published in April 2025 in the journal Nature Cell Biology, titled “PRMT5-mediated arginine methylation stabilizes GPX4 to suppress ferroptosis in cancer.”

Research Process and Results

1. The Relationship Between Methionine Metabolism and GPX4 Methylation

The study first identified the methionine metabolism enzyme MAT2A (methionine adenosyltransferase IIα) as playing a critical role in ferroptosis resistance through CRISPR-Cas9 screening in HEK-293T cells. Methionine is converted by MAT2A into S-adenosylmethionine (SAM), which acts as a methyl donor to trigger symmetric dimethylation of GPX4 at the arginine 152 site (R152). This methylation extends the half-life of GPX4, enhancing its stability.

Through methionine deprivation experiments, researchers found that the protein levels of GPX4 significantly decreased, while SAM supplementation restored GPX4 protein levels without affecting its mRNA levels. Further experiments demonstrated that methylation at the R152 site of GPX4 is crucial for its stability, and the absence of methylation leads to GPX4 degradation.

2. PRMT5-Mediated GPX4 Methylation

Researchers further discovered that PRMT5 is the key enzyme responsible for arginine methylation of GPX4. Through in vitro methylation experiments, researchers confirmed that PRMT5 catalyzes the methylation of GPX4 at the R152 site. Genetic or pharmacological inhibition of PRMT5 leads to a decrease in GPX4 methylation levels, thereby increasing its ubiquitination and degradation.

Additionally, researchers found that the absence of PRMT5 results in increased phosphorylation of GPX4, particularly at the T40/S44 sites. This phosphorylation promotes the binding of GPX4 to the E3 ubiquitin ligase FBW7, accelerating its ubiquitination and degradation.

3. FBW7-Mediated GPX4 Ubiquitination

Through co-immunoprecipitation experiments, researchers identified FBW7 as the E3 ubiquitin ligase for GPX4. FBW7 binds to the T40/S44 phosphorylation sites of GPX4 through its WD40 domain, promoting K48-linked polyubiquitination of GPX4, which leads to its degradation.

Further structural analysis revealed that the R152 site of GPX4 is spatially adjacent to the T40/S44 phosphorylation sites. PRMT5-mediated methylation of R152 hinders the phosphorylation of T40/S44, thereby preventing FBW7 from binding to GPX4 and enhancing its stability.

4. Combination Therapy with PRMT5 Inhibitors and Ferroptosis Inducers

Researchers validated the combined therapeutic effects of the PRMT5 inhibitor GSK3326595 and ferroptosis inducers (such as erastin and RSL3) in multiple cancer cell lines and mouse models. The results showed that PRMT5 inhibitors significantly enhanced the anticancer effects of ferroptosis inducers, suppressing tumor growth. This effect was attenuated in FBW7-knockout cancer cells, further validating the mechanism by which PRMT5 inhibits ferroptosis by regulating GPX4 stability.

Conclusions and Significance

This study reveals the molecular mechanism by which PRMT5 enhances the stability of GPX4 through methylation at the R152 site, thereby suppressing ferroptosis. This discovery provides new insights into how cancer cells evade ferroptosis through metabolic reprogramming and offers a theoretical basis for developing cancer treatment strategies targeting PRMT5.

The combination therapy of PRMT5 inhibitors and ferroptosis inducers demonstrated significant anticancer effects in multiple cancer cell lines and mouse models, indicating its potential clinical application value. Additionally, methylation at the R152 site of GPX4 is associated with patient prognosis in various cancers, further supporting its importance in cancer therapy.

Research Highlights

  1. Innovative Discovery: First to reveal that PRMT5 enhances GPX4 stability through methylation at the R152 site, thereby inhibiting ferroptosis.
  2. Combination Therapy Strategy: The combination of PRMT5 inhibitors and ferroptosis inducers showed significant anticancer effects in multiple cancer cell lines and mouse models, providing new insights for cancer treatment.
  3. Clinical Relevance: Methylation at the R152 site of GPX4 is associated with prognosis in various cancers, further supporting its potential application value in cancer therapy.

Other Valuable Information

This study also analyzed the spatial relationship between the R152 site and the T40/S44 phosphorylation sites of GPX4 using structural biology techniques, providing a structural basis for understanding how PRMT5 regulates GPX4 stability. Furthermore, researchers identified CK1 and GSK3β as potential key kinases responsible for the phosphorylation of GPX4 at T40/S44, offering clues for further research into the regulatory mechanisms of GPX4.

This study not only highlights the critical role of PRMT5 in ferroptosis regulation but also provides important theoretical and experimental support for developing new cancer treatment strategies.