Zhenbin Shen

Loss of RACK1 Promotes Metastasis of Gastric Cancer by Inducing a miR-302c/IL8 Signaling Loop

Gastric cancer remains the third leading cause of cancer-related mortality worldwide, and invasion and metastasis of gastric cancer represent the major reason for its poor prognosis. In this study, we found that loss of the receptor for activated C-kinase 1 (RACK1) promoted the metastasis of gastric cancer by enhancing the autocrine expression of IL8 in vitro and in vivo. microRNA (miRNA; miR) array identified that RACK1 modulated the expression of a series of miRNAs, including the miR-302 cluster, and RACK1 modulated the IL8 expression and tumor invasion through miRNA-302c. Moreover, upregulation of IL8 in turn decreased the level of miRNA-302c and induced IL8 expression in a feedback manner. Tissue microarray also indicated that RACK1 was correlated with invasion/metastasis phenotype, IL8 expression, as well as 5-year survival in clinical cases of gastric cancer. Together, our results imply that loss of RACK1 in gastric cancer links epigenetics to inflammatory cytokines to promote tumor metastasis.

Snail is an independent prognostic predictor for progression and patient survival of gastric cancer

The present study investigated the clinical significance of Snail, a zinc‐finger transcription factor, in the development and progression of gastric cancer. To elucidate the relationship between Snail expression and dedifferentiation status with cancer stem cell phenotype in gastric cancer cells, we used western blot analysis, RT‐PCR, quantitative real‐time PCR and flow cytometry. Immunohistochemistry staining and evaluation of Snail expression in 10 human normal gastric samples versus 103 clinicopathologically characterized gastric cancer tissues followed by statistical analyses were applied to evaluate the prognostic value of Snail expression for progression and patient survival of gastric carcinomas. The results showed that functional Snail expression interlinks dedifferentiation status with cancer stem cell phenotype in gastric cancer cells. In addition, expression levels of Snail in gastric cancer tissues were significantly associated with tumor cell differentiation, local tumor growth, lymph node status, distant metastasis and tumor stage. The overall survival rate of gastric cancer patients with high Snail expression was significantly lower than for those patients with low Snail expression. Multivariate Cox regression analyses showed that Snail expression is an independent prognostic predictor for patient survival of gastric carcinomas. Thus, our data suggest that Snail expression could be a reliable independent prognostic factor to predict gastric carcinoma progression, which might open a new avenue for potential clinical intervention with functional Snail expression in gastric cancer patients. (Cancer Sci 2012; 103: 1296–1303)

Upregulated Expression of C-X-C Chemokine Receptor 4 Is an Independent Prognostic Predictor for Patients with Gastric Cancer

Aberrant chemokine (C-X-C motif) receptor CXCR4 expressions in malignant tissues have been reported, but its role in gastric cancer prognosis remains unknown. Our studies were designed to investigate the expression and prognostic significance of CXCR4 in patients with gastric cancer. CXCR4 expression was retrospectively analyzed by immunohistochemistry in 97 patients with gastric adenocarcinoma from China. Results were assessed for association with clinical features and overall survival by using Kaplan-Meier analysis. Prognostic values of CXCR4 expression and clinical outcomes were evaluated by Cox regression analysis. A molecular prognostic stratification scheme incorporating CXCR4 expression was determined by using receiver operating characteristic (ROC) analysis. The results show that CXCR4 predominantly localized in the cell membranes and cytoplasm. The protein level of CXCR4 was upregulation in gastric cancer tissues and upregulated expression of CXCR4 was only significantly associated with Lauren classification (P<0.001). Increased CXCR4 expression in gastric cancer tissues was positively correlated with poor overall survival of gastric cancer patients (P<0.001). Further multivariate Cox regression analysis suggested that intratumoral CXCR4 expression was an independent prognostic indicator for the disease. Applying the prognostic value of intratumoral CXCR4 density to TNM stage system showed a better prognostic value in patients with gastric cancer. In conclusion, intratumoral CXCR4 expression was recognized as an independent prognostic marker for the overall survival of patients with gastric cancer. On the basis of TNM stage, detection of CXCR4 expression will be helpful for predicting prognosis for patients with gastric cancer.

BAY 11-7082, a nuclear factor-κB inhibitor, induces apoptosis and S phase arrest in gastric cancer cells

BackgroundInhibitors of nuclear factor (NF)-κB pathway have shown potential anti-tumor activities. However, it is not fully elucidated in gastric cancer.MethodsFirstly, we screened the inhibitory effect of pharmacologic NF-κB inhibitors on cell viability of human gastric cancer cells via CCK-8 assay. Next, cell apoptosis, cell cycle distribution, and mitochondrial membrane potential after BAY 11-7082 treatment were detected by annexin V staining, propidium iodide staining, TUNEL, and JC-1 assays in human gastric cancer HGC-27 cells. Expression of regulatory factors for apoptosis and cell cycle were measured by western blot. Finally, human gastric cancer xenograft model was established to verify the anti-tumor effects of BAY 11-7082 in vivo. Cellular apoptosis and growth inhibition in subcutaneous tumor section were detected by TUNEL and immunohistochemistry assays.ResultsBAY 11-7082 exhibited rapid and potent anti-tumor effects on gastric cancer cells in vitro within a panel of NF-κB inhibitors. BAY 11-7082 induced rapid apoptosis in HGC-27 cells through activating the mitochondrial pathway, as well as down-regulation of Bcl-2 and up-regulation of Bax. BAY 11-7082 also induced S phase arrest through suppressing Cyclin A and CDK-2 expression. Xenograft model confirmed the anti-tumor effects of BAY 11-7082 on apoptosis induction and growth inhibition in vivo.ConclusionsOur results demonstrated that BAY 11-7082 presented the most rapid and potent anti-tumor effects within a panel of NF-κB inhibitors, and could induce cellular apoptosis and block cell cycle progression both in vitro and in vivo, thus providing basis for clinical application of BAY 11-7082 in gastric cancer cases.

Increased expression of IDO associates with poor postoperative clinical outcome of patients with gastric adenocarcinoma.

Clinical significance of 2,3-dioxygenase (IDO) has been studied in types of tumors, but the role that IDO played in gastric adenocarcinoma (GAC) is still unclear. Here, we aim to investigate the prognostic value of IDO expression in patients with GAC. We examined intratumoral IDO expression in retrospectively enrolled 357 patients with GAC undergoing gastrectomy at Zhongshan Hospital of Fudan University in 2008 by immunohistochemical staining. The Kaplan-Meier method and Cox regression models were used to evaluate the prognostic value of IDO expression and its association with clinical pathological factors. We generated a predictive nomogram by integrating IDO expression with the TNM staging system for overall survival of GAC patients. High expression of intratumoral IDO predicted a dismal outcome. Intratumoral IDO expression gave a further discrimination for the prognosis of GAC patients. By Cox multivariate analysis, IDO expression was defined as an independent prognosticator. The generated nomogram performed well in predicting the 3- and 5-year overall survival of GAC patients. Conclusively, IDO is a potential prognostic biomarker for overall survival of patients with GAC after gastrectomy.

Clinical and prognostic implications of β1, 6-N-acetylglucosaminyltransferase V in patients with gastric cancer.

Aberrant β1, 6‐N‐acetylglucosaminyltransferase V (MGAT5) expression in malignant tissues has been reported to be involved in the development of various cancers and their progression, through altering N‐glycan branching. We aimed to investigate the clinical and prognostic values of MGAT5 and improve the risk stratification in patients with gastric cancer. MGAT5 expression was retrospectively analyzed by immunohistochemistry in three independent sets comprising 313 patients from China with gastric adenocarcinoma. Results were assessed for association with clinical features and overall survival using Kaplan–Meier analysis. Prognostic values of MGAT5 expression and clinical outcomes were evaluated by Cox regression analysis. A molecular prognostic stratification scheme incorporating MGAT5 expression was determined in patients with late‐stage gastric cancer by using receiver operating characteristic analysis. The results show that low intratumoral MGAT5 density, which was associated with poor differentiation, N classification, TNM stage, and Kiel stage, was an independent prognosticator for poor overall survival. The combination of intratumoral MGAT5 expression and TNM or Kiel staging systems had a better predictive power for overall survival. Applying the prognostic value of intratumoral MGAT5 density to TNM stage III+IV and Kiel stage IIIB+IV groups showed a better risk stratification for overall survival in patients with late‐stage gastric cancer. In conclusion, integrating intratumoral MGAT5 density that was recognized as an independent prognostic marker into current clinical staging systems significantly improved prognostic stratification of patients with late‐stage gastric cancer. This refined risk stratification scheme might aid in appropriate therapeutic options and ultimately improve the outcomes of patients with advanced‐stage disease.

Tumor-infiltrating Neutrophils is Prognostic and Predictive For Postoperative Adjuvant Chemotherapy Benefit in Patients With Gastric Cancer.

Objective: This study was aimed to investigate the prognostic value of tumor-infiltrating neutrophils (TINs) and to generate a predictive model to refine postoperative risk stratification system for patients with gastric cancer. Background: TIN presents in various malignant tumors, but its clinical significance in gastric cancer remains obscure. Methods: The study enrolled 3 independent sets of patients with gastric cancer from 2 institutional medical centers of China. TIN was estimated by immunohistochemical staining of CD66b, and its relationship with clinicopathological features and clinical outcomes were evaluated. Prognostic accuracies were evaluated by C-index and Akaike information criterion. Results: TINs in gastric cancer tissues ranged from 0 to 192 cells/high magnification filed (HPF), 0 to 117 cells/HPF, and 0 to 142 cells/HPF in the training, testing, and validation sets, respectively. TINs were negatively correlated with lymph node classification (P = 0.007, P = 0.041, and P = 0.032, respectively) and tumor stage (P = 0.019, P = 0.013, and P = 0.025, respectively) in the 3 sets. Moreover, multivariate analysis identified TINs and tumor node metastasis (TNM) stage as 2 independent prognostic factors for overall survival. Incorporation of TINs into well-established TNM system generated a predictive model that shows better predictive accuracy for overall survival. More importantly, patients with higher TINs were prone to overall survival benefit from postoperative adjuvant chemotherapy. These results were validated in the independent testing and validation sets. Conclusions: TIN in gastric cancer was identified as an independent prognostic factor, which could be incorporated into standard TNM staging system to refine risk stratification and predict for overall survival benefit from postoperative chemotherapy in patients with gastric cancer.

Overexpression of Ras-GTPase-activating protein SH3 domain-binding protein 1 correlates with poor prognosis in gastric cancer patients.

AIMS Ras-GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) is a downstream effector of Ras signalling, and is overexpressed in several types of human malignancy. However, its role in gastric cancer remains unclear. The aim of this study was to investigate the prognostic significance of G3BP1 in gastric cancer. METHODS AND RESULTS G3BP1 mRNA and protein levels in paired frozen tumour samples were detected by real-time polymerase chain reaction and western blotting, respectively. Paraffin-embedded tumour samples were used for immunohistochemistry. Gastric cancer cells were used to detect the tumorigenic role of G3BP1 in vitro. We found that G3BP1 protein expression was markedly increased in gastric cancer tissues as compared with corresponding non-malignant mucosa, whereas corresponding changes in mRNA levels were not observed. G3BP1 staining was positively correlated with tumour size, vascular invasion, T classification, lymph node metastasis, TNM stage, and reduced overall survival. Further analysis identified G3BP1 as an independent prognostic factor for poor prognosis, and combining G3BP1 with TNM stage generated a better predictive model for patient outcomes. G3BP1 also promoted proliferation, migration/invasion and extracellular signal-related kinase and AKT activation in gastric cancer cells. CONCLUSIONS Our data define G3BP1 as a novel independent prognostic factor that is correlated with gastric cancer progression.

Survival benefit of greater number of lymph nodes dissection for advanced node-negative gastric cancer patients following radical gastrectomy

OBJECTIVE A common clinicopathological factor except for T stage that could significantly influence the clinical outcome of advanced node-negative gastric cancer patients following radical gastrectomy was unknown. This study was designed to investigate the clinicopathological characteristics of these patients, and to evaluate the outcome indicators and improve the risk stratification. METHODS A total of 195 patients harboring advanced gastric adenocarcinoma with no lymph node and distant metastases and following radical gastrectomy were retrospectively analyzed from the prospectively collected database of Zhongshan Hospital of Fudan University between 2006 and 2010. RESULTS The 3-year and 5-year overall survival rates of this study population were 85.0 and 69.6%. Factors influencing the overall survival were the degree of tumor differentiation, the depth of invasion and the number of lymph nodes resected (LN, cutoff = 18). Lymph node was recognized as an independent prognostic factor for overall survival of advanced node-negative gastric cancer patients, and the prognosis of the patients with greater number of lymph nodes resected (LN ≥ 18) was significantly better than those with lymph node < 18, and only the patients with T3/T4 stage could be significantly stratified by lymph node. Based on this condition, a new staging system named tumor-node-metastasis staging system for T3/T4 node-negative gastric cancer was constructed, which could have statistically different overall survival between subgroups. CONCLUSIONS Lymph node was an independent prognostic factor of patients with advanced node-negative gastric cancer, and retrieval of more than 18 lymph nodes should be warranted. In addition, these patients with lesser number of lymph nodes resected might need aggressive postoperative treatment and closer follow-up.

Decreased expression of Calpain-9 predicts unfavorable prognosis in patients with gastric cancer

Calpain-8 and calpain-9 belong to the family of calcium-dependent cysteine proteases, which are highly expressed in the stomach. However, the roles of calpain-8 and calpain-9 in gastric tumorigenesis remain little understood. Herein, we demonstrated that calpain-9 was generally decreased in gastric cancer cell lines and primary tumor tissues, while calpain-8 expression was not significantly altered. Calpain-9, but not calpain-8, induced cell cycle arrest in the G1 phase and cellular apoptosis in vitro, and it attenuated the growth of subcutaneous tumor xenografts in vivo. Low expression of calpain-9 was positively associated with male sex, late T stage, lymph node metastasis, and advanced TNM stage. Further analysis identified calpain-9 as an independent prognostic factor for poor prognosis, and combining calpain-9 with TNM stage generated a better predictive model for patient outcomes. In conclusion, calpain-9 is a tumor suppressor that can be regarded as a potential prognosis indicator for clinical outcomes in gastric cancer.