Shmt2: A Stat3 Signaling New Player in Prostate Cancer Energy Metabolism

Area of Science:

• Oncology
• Molecular Biology
• Cancer Metabolism

Background:

• Prostate cancer (PCa) involves complex regulatory pathways, with STAT3 protein influencing metabolic enzymes.
• STAT3 activation is linked to aberrant metabolic activity in cancer cells, including the Warburg effect.

Purpose of the Study:

• To investigate the role of the STAT3 pathway and its interaction with SHMT2 in prostate cancer progression.
• To elucidate the molecular mechanisms linking inflammation, metabolic reprogramming, and PCa aggressiveness.

Main Methods:

• Bioinformatic analysis to identify STAT3 binding sites on the SHMT2 gene.
• In vitro studies using LNCaP cells (PCa cell line) to examine JAK2/STAT3 pathway activation and SHMT2 expression.
• Analysis of FFPE prostate tissue sections from patients with varying Gleason scores.

Main Results:

• IL-6 stimulation upregulated SHMT2 expression via the JAK2/STAT3 pathway in LNCaP cells.
• SHMT2 activation decreased serine levels, promoting nuclear PKM2 translocation and non-canonical STAT3 activation, leading to a shift towards anaerobic metabolism.
• A STAT3/SHMT2/PKM2 loop was identified in early-stage PCa, while a STAT3/HIF-1α/PKM2 loop maintained the Warburg effect in aggressive PCa.

Conclusions:

• The STAT3/SHMT2/PKM2 loop mediates metabolic shifts in response to inflammation during early PCa.
• Chronic inflammation may promote PCa progression through STAT3-mediated metabolic reprogramming.
• SHMT2 is a potential key factor in understanding the transition to aggressive prostate cancer phenotypes.