GARP: A Key Target to Evaluate Tumor Immunosuppressive Microenvironment

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• Glycoprotein-A repetitions predominant (GARP) acts as a receptor for latent transforming growth factor beta (LTGF-β), facilitating its activation.
• Elevated GARP expression is observed in various cancer types, present on tumor cells, regulatory T cells, and platelets within the tumor microenvironment (TME).

Purpose of the Study:

• To review the expression and function of GARP in the context of cancer.
• To evaluate membrane-bound GARP as a potential real-time biomarker for cancer prediction and therapeutic monitoring using molecular imaging.
• To examine soluble GARP as a circulating biomarker.

Main Methods:

• Literature review focusing on GARP expression, function, and biomarker potential in cancer.
• Analysis of GARP's role in the tumor microenvironment and TGF-β pathway.
• Exploration of molecular imaging techniques for assessing membrane GARP.
• Investigation of soluble GARP as a diagnostic marker.

Main Results:

• GARP is widely expressed in tumors and significantly contributes to active TGF-β production.
• The GARP-TGF-β pathway is implicated in immune evasion and cancer progression.
• Membrane GARP shows potential as a real-time biomarker detectable by molecular imaging.
• Soluble GARP is identified as a promising circulating biomarker.

Conclusions:

• GARP plays a critical role in cancer progression and immune evasion through TGF-β activation.
• Both membrane-bound and soluble GARP represent valuable biomarkers for cancer diagnosis, prognosis, and treatment monitoring.
• Molecular imaging of GARP could offer real-time insights into cancer status.