Mechanism of gambogic acid repressing invasion and metastasis of colorectal cancer by regulating macrophage...

Area of Science:

• Oncology
• Molecular Biology
• Immunology

Background:

• Colorectal cancer (CRC) poses a significant global health burden.
• Gambogic acid (GA) shows potential as an anti-CRC therapeutic.
• The role of tumor-derived extracellular vesicles (EVs) and microRNAs in CRC metastasis requires further elucidation.

Purpose of the Study:

• To investigate the mechanism by which Gambogic acid (GA) inhibits colorectal cancer (CRC) invasion and metastasis.
• To determine the specific role of tumor cell-derived extracellular vesicle (EV)-carried miR-21 in GA's anti-cancer effects.
• To examine GA's impact on macrophage polarization in the context of CRC metastasis.

Main Methods:

• A nude mouse peritoneal carcinomatosis (PC) model was treated with GA.
• miR-21 expression, macrophage markers (CD68, CD86, CD206), and cytokine levels (IL-12, IL-10) were quantified.
• In vitro studies assessed GA's effects on CRC cell proliferation, migration, invasion, and apoptosis, alongside EV characterization and macrophage uptake experiments.

Main Results:

• GA treatment reduced liver metastasis, miR-21 expression, and M2 macrophage polarization in vivo.
• GA decreased CRC cell proliferation, migration, and invasion while enhancing apoptosis in vitro.
• Tumor cell-derived EVs carried miR-21, and this miR-21 within EVs counteracted GA's suppressive effects on M2 polarization.

Conclusions:

• Gambogic acid (GA) effectively suppresses colorectal cancer (CRC) invasion and metastasis.
• GA exerts its effects by reducing miR-21 levels within tumor cell extracellular vesicles (EVs).
• GA's mechanism involves inhibiting M2 macrophage polarization, thereby weakening the pro-metastatic microenvironment.