PTEN Suppresses Glycolysis by Dephosphorylating and Inhibiting Autophosphorylated PGK1

Area of Science:

• Biochemistry
• Oncology
• Molecular Biology

Background:

• The PTEN tumor suppressor is crucial in cancer, regulating glucose metabolism via the PI3K-AKT pathway.
• Its direct role in controlling glycolysis within tumor cells remains largely undefined.

Purpose of the Study:

• To investigate the direct interaction between PTEN and phosphoglycerate kinase 1 (PGK1).
• To elucidate the role of PTEN in regulating PGK1 activity and its impact on glycolysis and tumorigenesis.

Main Methods:

• Co-immunoprecipitation assays to confirm PTEN-PGK1 interaction.
• In vitro phosphatase assays to assess PTEN's effect on PGK1 phosphorylation.
• Analysis of glycolytic intermediates, ATP levels, and cell proliferation.
• In vivo studies using knockin models and analysis of human glioblastoma specimens.

Main Results:

• PTEN directly binds to PGK1, a key glycolytic enzyme.
• PTEN dephosphorylates and inhibits PGK1's autophosphorylation at Y324, reducing glycolysis and ATP production.
• A PGK1 Y324F mutant suppressed brain tumor formation.
• PGK1 Y324 phosphorylation inversely correlates with PTEN expression in glioblastoma and predicts poor prognosis.

Conclusions:

• PTEN's phosphatase activity directly inhibits PGK1 activation and glycolysis.
• PGK1 autophosphorylation is essential for its activation and tumor cell proliferation.
• PTEN-PGK1 interaction represents a novel regulatory axis in cancer metabolism and tumorigenesis.