Expression and significance of TRAF6 in rectus abdominis of gastric cancer patients

Abstract

Objective To research the expression of tumor necrosis factor receptor-associated factor 6 (TRAF6) in rectus abdominis of gastric cancer patients and abdominal benign disease patients, and discuss the relationship between nutritional status and prognosis of gastric cancer patients with TRAF6. Methods Biopsies of the rectus abdominis were obtained intraoperatively from 64 gastric cancer patients and 53 subjects undergoing surgery for benign abdominal diseases. The expression levels of TRAF6 mRNA and protein were assessed through quantitative real time reverse transcriptase PCR (RT-QPCR) and Western blotting, and the relationships between nutritional status and prognosis of gastric cancer patients and the expression status of TRAF6 were analyzed. Results TRAF6 mRNA was significantly upregulated in muscle of stage Ⅰ (2.080±0.611), stage Ⅱ (2.126±0.640), stage Ⅲ (3.127±0.953), stage Ⅳ (3.289±0.734) gastric cancer compared with the control group (1.249±0.723), t=4.107, P=0.001; t=4.128, P=0.000; t=8.741, P=0.000; t=9.208, P=0.000. TRAF6 protein was significantly upregulated in muscle of stage Ⅰ (0.198±0.042), stage Ⅱ (0.209±0.051), stage Ⅲ (0.295±0.072), stage Ⅳ (0.345±0.084) gastric cancer compared with the control group (0.088±0.013), t=5.203, P=0.000; t= 5.642, P=0.000; t=9.351, P=0.000; t=9.854, P=0.000. TRAF6 was upregulated in 67.2% (43/64) of gastric cancer patients. The expression of TRAF6 in muscles of gastric cancer was associated with the percent of weight loss (χ2=12.231, P=0.000), the level of serum albumin (χ2=22.808, P=0.000) and the survival rate (χ2=3.933, P=0.047). Conclusion TRAF6 is significantly upregulated in rectus abdominis of gastric cancer, suggesting that TRAF6 may play an important role in progression and prognosis of cancer cachexia, and its overexpression suggests unfavorable prognosis. Key words: Stomach neoplasms; Rectus abdominis; Cachexia; Tumor necrosis factor receptor-asso-ciated factor 6