ABSTRACT
Objective To investigate the prognostic significance of proteolysis-inducing factor (PIF) in gastric cancer patients.Methods Biopsies of the rectus abdominis muscle were obtained intra operatively from 53 gastric cancer patients and 53 subjects undergoing surgery for benign abdominal diseases,muscle and serum PIF,ubiquitin expression,and proteasome proteolytic activities were assessed through reverse-transcription polymerase chain reaction (RT-PCR),Western blot,and enzyme-linked immunosorbent assay (ELISA).Results PIF was significantly upregulated in muscle of gastric cancer compared to control muscles.PIF was upregulated in 60％ (32/53) muscle of gastric cancer.Over expression of PIF in muscles of gastric cancer were associated with level of serum albumin,tumor node metastasis (TNM) stage,and percent of weight loss.The survival rate of patients with a high expression of PIF was significantly lower than those in patients with low expression (P ＜ 0.05).Conclusions PIF was significantly upregulated in muscle of gastric cancer,over expression of PIF in muscles of gastric cancer was associated with level of serum albumin,TNM stage,percent of weight loss,and prognosis.PIF might play an important role in progression and prognosis of gastric cancer.