Decreased Expression Of The Carboxyl Terminus Of Heat Shock Cognate70Interacing Protein In Human Gastric Cancer And Its Clinical Significance

Backgroud: The carboxyl terminus of heat shock cognate70interacting protein (CHIP) isan E3ubiquitin ligase, which can promote ubiquitylation and degradation of manytumor-related proteins. Reports have found CHIP expression decreased in human breastcancers in vivo. However, the expression of CHIP in human gastric cancer has not beeninvestigated.Materials and Methods: In this study, the mRNA and protein levels of CHIP expression in53cases of gastric cancer and matched normal tissues were determined by quantitativereal-time PCR, western blotting and immunohistochemistry. And the correlations betweenCHIP expression and the clinicopathological characteristics were also evaluated.Results: We showed that CHIP was registered from basal to middle portions of normalgastric mucosa. CHIP expression was notably decreased or lost in human gastric cancersamples compared with the matched normal non-cancer samples. The expression of CHIPwas significantly lower in the gastric cancer samples compared to the matched normalsamples at both mRNA and protein levels (P<0.05and P<0.05, respectively).Down-regulation of CHIP mRNA expression was found in37/53(70%) gastric cancerpatients, and CHIP protein expression was decreased in29/53(55%) gastric cancer patients,respectively. More importantly, the downregulation of CHIP was correlated with TNMstage (P=0.048) and lymph node metastasis (P=0.010) at the mRNA levels. In addition, thedownregulation of CHIP was correlated with lymph node metastasis (P=0.021) and tumordifferentiation (P=0.009) at the protein levels.Conclusions: At both mRNA and protein levels, the decreased expression of CHIP wascorrelated with lymph node metastasis. Furthermore, our study suggests that a negativecorrelation exists between CHIP expression and tumor malignancy in human gastric cancer.