Expression of Raf kinase inhibitor protein in human gastric cancer and its clinical significance / 中华消化杂志

ABSTRACT

Objective To investigate differential expression of Raf kinase inhibitor protein (RKIP)in gastric cancer and its clinical significance.Methods Pure gastric adenocarcinoma cells (GAC)and paracancerous gastric epithelial cells(NGEC)in 12 patient with gastric cancer were obtained using laser capture microdissection(LCM).After trypsin digestion all specimens were labeled with18O/16O.Quantitatively identification of differentially expressed proteins between GCC and NGEC was conducted using Nano-HPLC-MS/MS.The expression of RKIP in GAC was determined by Western blotting.Immunohistochemistry(IHC)was used to detect the expression of RKIP in gastric cancer(n=118),non-cancerous mucosa tissues(n=70)and matched positive lymph node tissues(n=35).Results A total of 78 differentially expressed proteins were identified and RKIP was downexpressed in GCC compared with NGEC(14.37).IHC examination revealed that positive expression of RKIP in gastric cancer had negative relation with deeper invasion,TNM stage and lymphoid node metastasis,while it had positive relation with histological differentiation(P＜0.05).Conclusion Down-regulation of RKIP in gastric cancer tissues might affect the biological behavior of gastric cancer.