Glyoxalase 2 Is Involved in Human Prostate Cancer Progression as Part of a Mechanism Driven By PTEN/PI3K/AKT/mTOR Signaling With Involvement of PKM2 and ERα

Prostate. 2017 Feb;77(2):196-210. doi: 10.1002/pros.23261. Epub 2016 Oct 3.

Abstract

Background: Glyoxalase 2 (Glo2), together with glyoxalase 1 (Glo1), forms the main scavenging system of methylglyoxal, a potent pro-apoptotic agent mainly generated by glycolysis. An increased rate of glycolysis is a well known signature of cancer cells. As a survival strategy, Glo1 is overexpressed in many human malignant cells, including prostate cancer (PCa), where it plays a crucial role in progression. No information is available on the role of Glo2 in the same ambit. PCa is the most common malignancy affecting men in the western world. Progression to a lethal hormone-refractory PCa represents the major concern in this pathology. Therefore, a deeper understanding of the molecular mechanisms underlying PCa invasiveness and metastasis is urgently needed in order to develop novel therapeutic targets for this incurable state of the malignancy.

Methods: Glo2 and Glo1 expression was examined in clinical samples of PCa by immunohistochemistry and in different PCa cell models by western blotting and quantitative real-time polymerase chain reaction. Gene silencing/overexpression and scavenging/inhibitory agents were used for functional analyses.

Results: We demonstrated that Glo2, together with Glo1, represents a novel mechanism in PCa progression as part of a pathway driven by PTEN/PI3K/AKT/mTOR signaling with involvement of PKM2 and ERα. Importantly, Glo1/Glo2 silencing did not alter the behavior of benign cells.

Conclusions: Targeting glyoxalases metabolic pathway may represent a strategy to selectively inhibit advanced PCa. Prostate 77:196-210, 2017. © 2016 Wiley Periodicals, Inc.

Keywords: ER-α; PKM2; PTEN; glyoxalases; prostate cancer.

MeSH terms

  • Biomarkers, Tumor / metabolism
  • Carrier Proteins / metabolism*
  • Cell Line, Transformed
  • Disease Progression
  • Estrogen Receptor alpha / metabolism*
  • Humans
  • Lactoylglutathione Lyase / metabolism*
  • Male
  • Membrane Proteins / metabolism*
  • PTEN Phosphohydrolase / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction / physiology
  • TOR Serine-Threonine Kinases / metabolism
  • Thiolester Hydrolases / metabolism*
  • Thyroid Hormone-Binding Proteins
  • Thyroid Hormones / metabolism*

Substances

  • Biomarkers, Tumor
  • Carrier Proteins
  • Estrogen Receptor alpha
  • Membrane Proteins
  • Thyroid Hormones
  • MTOR protein, human
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases
  • Thiolester Hydrolases
  • hydroxyacylglutathione hydrolase
  • PTEN Phosphohydrolase
  • PTEN protein, human
  • GLO1 protein, human
  • Lactoylglutathione Lyase