Regulation of metabolism by hypoxia-inducible factor 1

Area of Science:

• Cellular Biology
• Cancer Metabolism
• Molecular Oncology

Background:

• Oxygen homeostasis is vital for survival, regulated by hypoxia-inducible factor 1 (HIF-1).
• Cancer cells exhibit altered metabolism, favoring glycolysis even with sufficient oxygen.
• Pyruvate kinase M2 (PKM2) is implicated in cancer growth, but its mechanism is unclear.

Purpose of the Study:

• To elucidate the mechanism by which PKM2 influences cancer metabolism and progression.
• To investigate the interaction between PKM2 and HIF-1α in cancer cells.

Main Methods:

• Studied the physical and functional interaction between PKM2 and HIF-1α.
• Investigated the role of PHD3 in mediating PKM2 and HIF-1α interaction.
• Analyzed the impact of PHD3 knockdown on gene expression and cellular metabolism.

Main Results:

• PKM2 physically and functionally interacts with HIF-1α, enhancing HIF-1 binding to target genes, coactivator recruitment, and histone acetylation.
• PHD3 facilitates PKM2 interaction with HIF-1α via hydroxylation.
• PHD3 knockdown reduced expression of metabolic genes (e.g., GLUT1, LDH-A, PDK1), glucose uptake, and lactate production, while increasing oxygen consumption.
• VEGF expression was also regulated by the PKM2/PHD3 pathway.

Conclusions:

• PKM2 promotes cancer metabolic reprogramming and progression through interaction with HIF-1α.
• The PKM2/PHD3 axis plays a significant role in regulating cancer cell metabolism and gene transcription.
• PKM2 has a broader role in cancer progression than previously recognized.