Phosphoenolpyruvate Carboxykinase Maintains Glycolysis-driven Growth in Drosophila Tumors

Area of Science:

• Cancer Biology
• Metabolic Pathways
• Drosophila melanogaster Models

Background:

• Chromosomal instability (CIN) is a hallmark of cancer, leading to aneuploidy and oxidative stress.
• CIN tumors exhibit unique metabolic vulnerabilities compared to normal cells.
• Targeting these metabolic differences offers a potential strategy for cancer therapy.

Purpose of the Study:

• To identify metabolic interventions against CIN tumors in Drosophila.
• To exploit metabolic differences between normal and CIN cells for therapeutic benefit.
• To investigate the role of phosphoenolpyruvate carboxykinase (PEPCK) in CIN tumor growth.

Main Methods:

• Utilized Drosophila melanogaster as a model organism.
• Employed RNA interference (RNAi) to deplete metabolic enzymes.
• Administered PEPCK inhibitors and manipulated NAD+/NADH levels.
• Blocked the glycerol-3-phosphate shuttle to assess its impact on tumor growth.

Main Results:

• Depletion of PEPCK significantly inhibited CIN tumor growth in a brat tumor explant model.
• Increasing NAD+ or oxidizing cytoplasmic NADH rescued growth in PEPCK-depleted tumors, indicating impaired NADH clearance.
• Blocking the glycerol-3-phosphate shuttle also inhibited tumor growth and reduced reactive oxygen species (ROS) levels.

Conclusions:

• Proliferating CIN cells are uniquely susceptible to PEPCK inhibition due to their compromised redox status.
• Targeting PEPCK or its associated metabolic network presents a promising therapeutic strategy for CIN-driven cancers.
• Metabolic interventions can selectively target cancer cells while sparing normal host tissues.