PHLDA2-mediated phosphatidic acid peroxidation triggers a distinct ferroptotic response during tumor suppression

Area of Science:

• Oncology
• Cellular Biology
• Immunology

Background:

• Ferroptosis is recognized for its tumor-cell-killing ability.
• However, ferroptosis inducers can impair anti-tumor immunity by affecting neutrophils, potentially promoting tumor growth.
• This raises questions about ferroptosis' efficacy in suppressing tumors in vivo.

Purpose of the Study:

• To investigate a novel ferroptosis pathway.
• To determine if ferroptosis can suppress tumors independently of common inducers and immune interactions.

Main Methods:

• Genome-wide CRISPR-Cas9 screening was employed to identify new ferroptosis pathways.
• Experiments utilized both immunodeficient and immunocompetent mouse tumor models.
• Mechanisms involved reactive oxygen species (ROS) and phosphatidic acid (PA) peroxidation.

Main Results:

• A PHLDA2-mediated ferroptosis pathway was discovered, distinct from ACSL4-dependent pathways and not requiring external inducers.
• This PHLDA2-mediated ferroptosis involves phosphatidic acid peroxidation driven by high reactive oxygen species (ROS) levels.
• Loss of PHLDA2 abolished ROS-induced ferroptosis, promoting tumor growth without affecting normal tissues in mouse models.

Conclusions:

• PHLDA2-mediated phosphatidic acid peroxidation initiates a unique ferroptosis response critical for tumor suppression.
• This pathway demonstrates that ferroptosis can naturally occur in vivo without external inducer treatment.
• PHLDA2-mediated ferroptosis represents a promising target for cancer therapy, distinct from current ferroptosis inducer strategies.