OBJECTIVETo investigate the expression of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) in the serum and the rectus abdominis muscle in patients with gastric cancer and its relationship with the nutritional status. Method Clinical data of 102 patients with gastric cancer (gastric cancer group) and 53 patients with benign abdominal disease (control group) who were admitted to Zhejiang Province People's Hospital from January 2008 to October 2013 were analyzed retrospectively. Enzyme-linked immunosorbent assay(ELISA) was used to detect the serum expression of TWEAK. Reverse transcription polymerase chain reaction (RT-PCR) and Western blot were used to detect the mRNA and protein expression of TWEAK in the rectus abdominis muscle. Relationship between TWEAK expression and nutritional status of gastric cancer patients was examined.

RESULTSThe relative expression level of TWEAK protein in serum of gastric cancer group and control group was 0.403±0.065 and 0.148±0.036 respectively. The relative expression of TWEAK mRNA in the rectus abdominis muscle tissue was 0.313±0.089 (gastric cancer group) and 0.118±0.005 (control group). The relative expression of TWEAK protein in the rectus abdominis muscle tissue was 0.197±0.064 (gastric cancer group) and 0.066±0.014 (control group), and the differences were statistically significant (both P=0.000). The high expression of TWEAK (high than median) in rectus abdominis muscle of gastric cancer patients was related to the percentage of more than 10% decline in body weight (P=0.000), the small percentage of ideal body weight at the time of admission (P=0.000), BMI<20 kg/m(P=0.023), higher NRS2002 nutritional risk screening score (P=0.000), lower prognostic nutrition index (P=0.000) and serum albumin <35 g/L (P=0.000).

CONCLUSIONSThe expression of TWEAK in serum and rectus abdominis muscle of gastric cancer patients up-regulates compared to non-tumor patients. The expression level of TWEAK in the rectus abdominis muscle of gastric cancer patients is closely related to poor nutritional status, suggesting that TWEAK may play a key role in the process of cachexia of gastric cancer patients.