Résumé
Objective To look into the effect of ubiquitin (Ub) in muscles of gastric cancer patients on their nutritional status and prognosis.Methods Abdominal rectus muscles of 102 patients with gastric cancer and 53 patients with benign abdominal diseases were studied.The expressions of Ub mRNA and protein were assessed through real time-PCR and Western blot.Results The relative expression of Ub mRNA in rectus abdominis muscles of gastric cancer patients (4.10± 1.04) was significantly upregulated compared with the control group (3.17±0.32) (t =7.386,P=0.000).The expression of Ub protein in rectus abdominis muscles of patients with gastric cancer was upregulated compared with the controls (0.151 ±0.058 vs.0.084±0.046,t =7.275,P =0.000).The high expression of Ub mRNA in rectus abdominis muscles of gastric cancer patients was significantly associated with decreases in weight,body mass index,prognostic nutritional index,serum albumin and hemoglobin (x2 =11.780,6.557,11.849,15.742,8.360;P=0.001,0.010,0.001,0.000,0.004).The high expression of Ub mRNA in rectus abdominis muscles of gastric cancer patients was not correlated with the patients'sex,age,tumor size or Borrmann type (x2 =0.038,1.978,0.486,1.483;P=0.774,0.160,0.486,0.223),but it was related to the pathologic type,lymph node metastasis and TNM staging of gastric carcinoma (x2 =11.260,9.362,20.517;P=0.004,0.002,0.000).The survival rate of gastric cancer patients with high expression of Ub mRNA was lower than those with low expression (x2 =5.775,P =0.016).Conclusions Ub mRNA and protein were upregulated in rectus abdominis muscles of gastric cancer patients.The high expression of Ub mRNA in these patients was related to their nutritional status and prognosis,which might play an important role in the development of cachexia.
Résumé
Objective To investigate the expressions of myostatin (MSTN) in the gastric cancer patients' rectus abdominis and serum,and to discuss its relation with the nutritional status and outcome of the gastric cancer patients.Methods We recruited 102 patients with gastric cancer and another 53 patients with benign abdominal disease who were admitted to Zhejiang Province People's Hospital and Tongde Hospital of Zhejiang Province from February 2008 to February 2011.We tested MSTN expression in the malignant patients' rectus abdominis and serum using reverse transcription polymerase chain reaction,Western blot,and enzymelinked immunosorbent assay.Relationship between MSTN expression and nutrition status of gastric cancer patients was explored.Results The relative expression of MSTN mRNA of rectus abdominis muscle in gastric cancer group and control group was 3.43 ± 1.11 and 1.07 ± 0.31 (t =19.406,P ＜ 0.01),the relative expression level of MSTN protein in gastric cancer group and control group was 0.115±0.696 and 0.085±0.499 (t=2.856,P＜0.05) and its serum expression 8.79±4.32 and 1.21±0.55 in these two group (t =16.701,P＜0.05),showing significant difference.The high (defined as higher than median) expression of MSTN in rectus abdominis muscle of gastric cancer patients was significantly correlated with age (x2 =22.039,P =0.000),percentage of more than 10％ decline in body weight in half a year (x2 =14.365,P=0.000),body mass index (BMI) ＜22 kg/m2 (x2 =6.800,P=0.009),serum albumin (x2 =31.018,P=0.000),hemoglobin (x2=10.079,P =0.001),prognostic nutritional index (x2 =10.074,P =0.002),higher Nutritional Risk Screening 2002 Score (Z=2.628,P=-0.009),tumor stage of TNM (Z=2.550,P=0.011).The expression of the rectus abdominis muscle in patients with gastric cancer was significantly correlated with the survival rate of the patients (x2 =12.200,P＜0.01).Conclusions The expression of MSTN increases in the rectus abdominis and serum of gastric cancer patients with cachexia.The increased MSTN expression is closely related with malnutrition and TNM stage in these patients,suggesting MSTN may also play an important role in the muscle consumption of the gastric cancer patients.