Cyclooxygenase-2 inhibition as a strategy for treating gastric adenocarcinoma

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Cyclooxygenase-2 (COX-2) plays a significant role in inflammation and cancer development.
• Celecoxib, a COX-2 inhibitor, demonstrates anti-inflammatory, immunosuppressive, and anti-arthritic effects.
• The specific function of COX-2 in human gastric adenocarcinoma (GAC) requires further investigation.

Purpose of the Study:

• To investigate the role of COX-2 in human gastric adenocarcinoma (GAC).
• To assess the expression of COX-2 and proliferating cell nuclear antigen (PCNA) in GAC tissues.
• To evaluate the effects of COX-2 inhibition on GAC cell behavior and underlying molecular mechanisms.

Main Methods:

• Immunohistochemical analysis of COX-2 and PCNA expression in 45 GAC tissues and adjacent non-cancerous tissues (ANCTs) using tissue microarrays.
• In vitro studies involving GAC cell lines (SGC-7901 and MKN-45) treated with COX-2 siRNA or celecoxib.
• In vivo experiments using a subcutaneous tumor model in mice with MKN-45 cells treated with siCOX-2.

Main Results:

• COX-2 and PCNA expression were significantly higher in GAC tissues compared to ANCTs (80.0% vs. 53.3% and 68.9% vs. 48.9%, respectively).
• Elevated COX-2 expression correlated positively with lymph node metastasis in GAC patients.
• Inhibition of COX-2, via siRNA or celecoxib, suppressed GAC cell proliferation, migration, and invasion, accompanied by decreased PCNA expression.
• Tumor volume was significantly reduced in the siCOX-2 treated group compared to the control group in vivo.

Conclusions:

• COX-2 is overexpressed in human gastric adenocarcinoma and is associated with disease progression.
• Targeting COX-2 signaling, through inhibition or knockdown, effectively suppresses GAC cell proliferation and invasion.
• These findings provide a strong preclinical basis for targeting COX-2 as a therapeutic strategy for gastric adenocarcinoma.