Methionine is a metabolic dependency of tumor-initiating cells

Area of Science:

• Oncology
• Cancer Metabolism
• Epigenetics

Background:

• Cancer cells exhibit altered metabolic pathways compared to normal tissues.
• Tumor-initiating cells (TICs) are critical therapeutic targets but remain metabolically uncharacterized.
• Understanding TIC metabolism is key for developing novel cancer therapeutics.

Purpose of the Study:

• To characterize the metabolic alterations in tumor-initiating cells (TICs).
• To investigate the role of the methionine cycle in TIC function and cancer initiation.
• To explore MAT2A as a potential therapeutic target in cancer.

Main Methods:

• Metabolomics analysis
• Metabolite tracing analysis
• Pharmacological inhibition of methionine cycle enzymes

Main Results:

• TICs exhibit significantly elevated methionine cycle activity and transmethylation rates, driven by MAT2A.
• High methionine cycle activity leads to an addiction to exogenous methionine.
• Transient inhibition of the methionine cycle impairs TIC tumor-initiating capability.
• Methionine cycle flux impacts cancer cell epigenetic state and drives tumor initiation.

Conclusions:

• The methionine cycle, particularly MAT2A, is a critical metabolic vulnerability in TICs.
• Targeting the methionine cycle offers a promising therapeutic strategy for cancer, impacting tumor initiation and epigenetic regulation.
• MAT2A expression influences sensitivity to therapeutic inhibition in various cancer types.