Low Expression Levels of Peroxisome Proliferator-Activated Receptor Gamma (PPARγ) in Gastric Cancer and its Relationship with Tumor Progression

Abstract

Background: Peroxisome proliferator-activated receptor gamma (PPARγ) plays a crucial role in hindering the progression and growth of cancer cells. The function of PPARγ in gastric cancer and its relationship with progression of the disease have not been appropriately defined. Therefore, this study examined the association of PPARγ expression in tumor with advancement of gastric cancer. Methods: In the cross-sectional case-control study, the expression of PPARγ in tumoral and the paired adjacent normal tissues of 50 patients with gastric cancer, who undergone tumor resection at Institute of Imam Khomeini University Hospital, Tehran, Iran, were assayed and compared using quantitative real-time polymerase chain reaction method. Correlation between PPARγ expression in tumor tissue and the cancer progression relevant clinicopathological features was evaluated using the Spearman’s rho correlation test. Findings: The relative expression levels of PPARγ in tumoral tissues were shown to be profoundly decreased compared with their adjacent normal tissues [0.36 (0.15-0.89) vs. 1.01 (0.83-1.16), P < 0.001]. There was significant correlation between the relative expression level of PPARγ in tumoral tissues and clinicopathological features such as cancer staging, tumor differentiation, tumor size, and lymphatic and vascular invasion. However, there was no noticeable correlation between the relative PPARγ expression level and other features such as age, gender, and metastasis. Conclusion: Decreased expression of PPARγ in gastric cancer tissue compared to the adjacent normal tissues is inversely associated with the cancer progression and development relevant clinicopathological features; hence, it may play an important role in the pathophysiology of gastric cancer.

Keywords

• PPAR gamma
• Gastric cancer
• Cancer staging
• Disease progression