Cyclooxygenase inhibitors suppress angiogenesis and reduce tumor growth in vivo

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Angiogenesis is crucial for malignant tumor development.
• Cyclooxygenase (COX) enzymes are implicated in tumor growth and angiogenesis.

Purpose of the Study:

• To investigate the effects of COX inhibitors on gastrointestinal cancer xenografts.
• To clarify the roles of COX-1 and COX-2 in tumor angiogenesis and growth.

Main Methods:

• In vivo study using nude mice with two types of gastrointestinal cancer xenografts (COX-2 overexpressing and non-COX expressing).
• Oral administration of specific COX-2 or non-specific COX inhibitors.
• Assessment of tumor volume, angiogenesis, expression of angiogenic factors (VEGF, bFGF), apoptosis, and cell replication.

Main Results:

• Positive correlation observed between tumor volume and angiogenesis.
• COX inhibitors dose-dependently reduced angiogenesis, growth, and expression of VEGF and bFGF in COX-2 overexpressing xenografts.
• Non-specific COX inhibitors, but not COX-2 specific inhibitors, reduced growth and angiogenesis in non-COX expressing xenografts by inhibiting COX-1 in vascular endothelial cells.

Conclusions:

• COX inhibitors suppress tumor angiogenesis and growth by inhibiting angiogenic factor expression and vascular endothelial cell proliferation.
• COX plays a significant role in cancer growth through angiogenesis.
• COX inhibitors (NSAIDs) represent a potential therapeutic strategy against cancer.