IGFBP2 alteration contributes to prostate cancer progression by modulating prostate stroma activation

Area of Science:

• Oncology
• Molecular Biology
• Cancer Research

Background:

• Insulin-like growth factor binding protein-2 (IGFBP2) is a secretory protein modulating IGF activity.
• IGFBP2 is highly expressed in prostate cancer (PCa), with an unclear role in tumor progression.

Purpose of the Study:

• To investigate the expression pattern and role of IGFBP2 in PCa cells and associated stroma.
• To elucidate the molecular mechanisms underlying IGFBP2's involvement in prostate tumor progression.

Main Methods:

• Examined IGFBP2 expression in PCa cells and prostate stromal fibroblasts (PrSCs).
• Assessed the impact of IGFBP2 knockdown (siIGFBP2) and recombinant IGFBP2 (rIGFBP2) on tumor cell behavior.
• Analyzed cytokine secretion and TGF-β signaling pathways.

Main Results:

• IGFBP2 was highly expressed and secreted by PrSCs.
• IGFBP2 did not directly affect tumor cell growth or invasiveness.
• Reduced IGFBP2 expression increased PrSC activation and pro-tumorigenic cytokine secretion (IL-6, IL-8, IP10, CCL5) via TGF-β upregulation, enhancing PCa progression.
• Low stromal IGFBP2 correlated with reactive stroma, advanced PCa, and elevated serum IGFBP2.

Conclusions:

• IGFBP2 is a critical regulator of prostate stromal microenvironment activation.
• IGFBP2 contributes mechanistically to aggressive PCa progression.
• Stromal IGFBP2 levels serve as a potential biomarker for PCa aggressiveness.