Nucleotide biosynthesis links glutathione metabolism to ferroptosis sensitivity

Area of Science:

• Cellular biology
• Biochemistry
• Molecular oncology

Background:

• Nucleotide synthesis is vital for cellular functions like DNA replication.
• While some anticancer drugs induce apoptosis by inhibiting nucleotide metabolism, their effect on non-apoptotic cell death remains unclear.
• Ferroptosis is a distinct form of programmed cell death influenced by cellular metabolism.

Purpose of the Study:

• To investigate the impact of inhibiting nucleotide metabolism on ferroptosis.
• To elucidate the role of the p53 pathway in regulating ferroptosis through metabolic control.

Main Methods:

• Utilized p53 pathway activation to inhibit nucleotide metabolism.
• Measured expression of p53 target genes, including CDKN1A (p21).
• Assessed ribonucleotide reductase (RNR) subunit expression (RRM1 and RRM2).
• Quantified intracellular glutathione levels and lipid peroxide accumulation.
• Induced ferroptosis via cystine deprivation.

Main Results:

• p53 pathway activation suppressed ferroptosis.
• Stabilization of wild-type p53 led to CDKN1A (p21) induction.
• This resulted in decreased expression of RNR subunits (RRM1 and RRM2).
• Direct RNR inhibition conserved intracellular glutathione and limited toxic lipid peroxides.
• These effects prevented ferroptosis onset during cystine deprivation.

Conclusions:

• p53-dependent regulation of nucleotide metabolism is sufficient to suppress ferroptosis.
• The p53-CDKN1A-RNR axis plays a critical role in preventing ferroptosis.
• This study reveals a novel link between nucleotide synthesis control and non-apoptotic cell death pathways.