Astrocyte-elevated gene-1 overexpression is associated with poor prognosis in gastric cancer

Astrocyte-elevated gene-1 (AEG-1) plays an important role in diverse cancers and its up-regulation is associated with poor survival of patients. However, the status of AEG-1 expression and its significance in gastric cancer are still unclear. In this study, the expression of AEG-1 was studied in different gastric cancer cell lines and gastric cancer tissues. Expression of AEG-1 was significantly higher in gastric cancer tissues than that in normal tissues. Overexpression of AEG-1 was found in 62.9% of gastric cancers and significantly associated with TNM stage and Ki-67 proliferation index (P < 0.01). For survival study, overexpression of AEG-1 was significantly associated with poor survival (P < 0.01). Further multivariate analysis suggested that AEG-1 overexpression was an independent prognostic factor for the disease. We demonstrated that inhibition of AEG-1 expression by specific siRNA clearly inhibited SGC-7901 cell growth and enhanced cell apoptosis (P < 0.01). Inhibition of AEG-1 reduced phosphorylation of AKT and glycogen synthase kinase (GSK)-3β (Ser 9) and decreased the level of β-catenin, lymphoid enhancer binding factor 1 (LEF1), and Cyclin D1. This indicated that AEG-1 may play a role in Wnt/β-catenin-mediated cancer progression. Taken together, overexpression of AEG-1 could be a useful prognostic factor in patients with gastric cancer. Targeted inhibition of AEG-1 may provide a novel therapeutic strategy for gastric cancer.     

Nuclear PRMT1 expression is associated with poor prognosis and chemosensitivity in gastric cancer patients

Background

Metastatic and refractory gastric cancer (GC) are associated with a poor prognosis; therefore, the identification of prognostic factors and chemosensitivity markers is extremely important. Protein arginine methyltransferase 1 (PRMT1) may play a role in chemosensitivity/apoptosis induction via activation of the tumor suppressor forkhead box O1 (FOXO1). The purpose of this study was to clarify the expression of and relationship between PRMT1 and FOXO1 to evaluate the applicability of PRMT1 as a prognostic marker and a therapeutic tool in GC.

Methods

We investigated the clinical and functional significance of PRMT1 and FOXO1 in 195 clinical GC samples using immunohistochemistry. We performed suppression analysis of PRMT1 using small interfering RNA to determine the biological roles of PRMT1 in chemosensitivity.

Results

PRMT1 and FOXO1 in GC samples were predominantly expressed in the nucleus. Patients with lower PRMT1 expression (n = 131) had suppressed nuclear accumulation of FOXO1, higher recurrence after adjuvant chemotherapy, and poorer prognosis than those with higher PRMT1 expression (n = 64). PRMT1 downregulation in GC cells by RNA interference inhibited cisplatin and 5-fluorouracil sensitivity. The expression of phosphorylated FOXO1 and phosphorylated BCL-2 antagonist of cell death was upregulated in PRMT1 small interfering RNA groups.

Conclusion

Our data suggest that the evaluation of PRMT1 expression in GC is a useful predictor of poor prognosis and recurrence after adjuvant chemotherapy. Moreover, these data suggest that PRMT1 is a promising therapeutic tool for overcoming refractory GC.

     

Methylation of ASC/TMS1 promoter is associated with poor prognosis of patients with gastric cancer

Objective

This study was conducted to explore the prognostic value of the methylation status of the ASC/TMS1 (apoptosis-associated speck-like protein containing a CARD/the target of methylation-induced silencing-1) promoter in gastric cancer (GC).

Methods

ASC/TMS1 expression was detected in GC tissues and normal gastric mucosal tissues by real-time quantitative PCR and Western blot analysis. Methylation-specific PCR (MSP) analysis was performed to detect the methylated degrees of the DNA of the ASC/TMS1 promoter of 200 GC patients. Associations between molecular, clinicopathological characteristics and survival data were analyzed.

Results

The mRNA and protein expression levels of ASC/TMS1 in GC tissues were lower than those in normal gastric mucosal tissues. With the MSP detection, ASC/TMS1 promoter methylation was found in 68 (34 %) in 200 GC tissues, while none of 40 normal gastric mucosal tissues were found to be methylated. The size of primary tumor and lymph node metastasis were identified as independent relative factors of methylation status of the ASC/TMS1 promoter in GC tissues. Multivariate analysis results demonstrated that the degree of differentiation, serosal invasion, lymph node metastasis and methylated status of ASC/TMS1 promoter were independent prognostic indicators of GC. Lymph node metastasis and methylated status of ASC/TMS1 promoter were optimal prognostic predictors of GC patients, as identified by Cox regression with Akaike information criterion value calculation.

Conclusions

The methylated status of ASC/TMS1 promoter had the potential applicability for clinical evaluation the prognosis of GC.

     

Negative Helicobacter pylori status is associated with poor prognosis in patients with gastric cancer

BACKGROUND:

Recent studies have suggested that Helicobacter pylori (H. pylori) infection may be related to better prognosis in patients with gastric cancer, but to the authors' knowledge, this finding has not yet been validated. In the current study, the association between H. pylori status and clinical outcome was investigated in a large cohort of patients.

METHODS:

Frozen non‐neoplastic gastric mucosa and serum samples obtained from 297 patients who underwent surgery for primary gastric cancer between 1988 and 2004 were retrieved from the serum and tissue bank of the study department. H. pylori status was defined by means of polymerase chain reaction (PCR) analysis for the vacA gene in gastric mucosa and by serologic assay of H. pylori and CagA antibodies. Univariate and multivariate analyses were used for the association between clinicopathologic variables and long‐term outcome.

RESULTS:

Positivity for H. pylori infection was observed in 256 of 297 patients (86%), whereas in 41 patients (14%), PCR for vacA and both serologic tests were negative. Negative H. pylori status was found to be significantly associated with cardia location, advanced pT classification, noncurative surgery, and a lower 5‐year survival rate after R0 resection (24% vs 57%; P < .001). Multivariate survival analysis confirmed H. pylori status as a significant prognostic factor (hazards ratio, 2.47; 95% confidence interval, 1.40‐4.35 [P = .002]). The influence of H. pylori status on long‐term survival was observed in patients with early as well as advanced pT classifications.

CONCLUSIONS:

Negative H. pylori status appears to be an indicator of poor prognosis in patients with gastric cancer, and is independent of other well?known clinical and pathologic prognostic variables. Cancer 2009. © 2009 American Cancer Society.     

Overexpression of keratin 17 is associated with poor prognosis in epithelial ovarian cancer

The aim of this study was to investigate the association between keratin 17 (K17) expression and the clinicopathological features of patients with epithelial ovarian cancer (EOC). K17 expression was detected by real-time quantitative RT-PCR in EOC and adjacent noncancerous tissues. In addition, K17 expression was analyzed by immunohistochemistry in 104 clinicopathologically characterized EOC cases. The expression levels of K17 mRNA and protein in EOC tissues were both significantly higher than those in noncancerous tissues. In addition, positive expression of K17 correlated with the clinical stage (p?=?0.001). Furthermore, Kaplan–Meier survival analysis showed that a high expression level of K17 resulted in a significantly poor prognosis of EOC patients. Multivariate analysis revealed that EOC expression level was an independent prognostic parameter for the overall survival rate of EOC patients. Our data are the first to suggest that increased K17 expression in EOC is significantly associated with aggressive progression and poor prognosis. K17 may be an important molecular marker for predicting the carcinogenesis, progression, and prognosis of EOC.     

Overexpression of minichromosome maintenance 2 predicts poor prognosis in patients with gastric cancer

We examined the expression of minichromosome maintenance 2 (MCM2) in gastric cancer and adjacent normal tissues and estimated the possible value of MCM2 as a novel prognostic marker. Using real-time PCR, western blotting and immunohistochemistry, we examined the expression of MCM2 in gastric carcinoma and paired normal gastric mucosa. Statistical analysis of the expression of MCM2 mRNA and protein in gastric cancer and normal tissues was performed to evaluate the relationship between MCM2 expression and clinicopathological characteristics in gastric cancer. The expression of MCM2 mRNA and protein in gastric carcinomas was significantly higher compared to that in normal gastric mucosa (P=0.04). Immunohistochemistry analysis showed that MCM2 expression was significantly up-regulated in tumor and metastastic lymph node tissues compared with the corresponding non-cancerous mucosa (P<0.05). Positive expression of MCM2 was significantly associated with patient age, T category and the presence of lymph node metastasis (P<0.05). There were no differences between MCM2 expression and gender, tumor size, tumor location, M category, International Union Against Cancer (UICC) stage, vessel invasion and tumor differentiation. Patients with negative tumor MCM2 expression displayed a better survival time than those with positive MCM2 expression (P<0.05). Survival analysis showed that positive MCM2 expression (P<0.05), T stage (P<0.05) and N stage (P<0.05) were independent prognostic factors for disease-free survival (DFS) and overall survival (OS). Our data suggest that MCM2 could serve as a novel prognostic biomarker in gastric carcinoma.     

High RIN1 expression is associated with poor prognosis in patients with gastric adenocarcinoma

The aim of this study was to investigate the expression and prognostic significance of RIN1 in gastric adenocarcinoma. RIN1 expression was analyzed using quantitative real-time PCR (qRT-PCR), Western blotting, and immunohistochemical staining on tissue samples from a consecutive series of 315 gastric adenocarcinoma patients who underwent tumor resections between 2003 and 2006. The relationship between RIN1 expression, clinicopathological factors, and patient survival was investigated. qRT-PCR results showed that the RIN1 mRNA expression was higher in tumor tissue samples than in the adjacent normal tissues, and a corresponding increase in protein expression was confirmed by Western blotting. Immunohistochemical staining indicated that RIN1 is highly expressed in 54.3?% of gastric adenocarcinomas. RIN1 expression levels were closely associated with tumor size, histological differentiation, tumor stage, and lymph node involvement. Kaplan?CMeier survival analysis showed that high RIN1 expression exhibited a significant correlation with poor prognosis for gastric adenocarcinoma patients. Multivariate analysis revealed that RIN1 expression is an independent prognostic parameter for the overall survival rate of gastric adenocarcinoma patients. Our data suggest that RIN1 plays an important role in gastric adenocarcinoma progression and that a high RIN1 expression predicts an unfavorable prognosis in gastric adenocarcinoma patients.     

Overexpression of G6PD is associated with poor clinical outcome in gastric cancer

This study aims to investigate the expression and significance of glucose-6-phosphate dehydrogenase (G6PD) in human gastric cancer progression and prognosis. Using immunohistochemistry and real-time RT-PCR assay, we identified abnormally elevated expression of G6PD in gastric cancer tissues compared to paired normal stomach mucosa tissues in 24 patients (p < 0.05). In order to investigate the correlations between G6PD and the clinicopathological features of gastric cancer, the expression of G6PD in 167 patients with gastric cancer were detected by immunohistochemistry, and the results showed that overexpression of G6PD was associated with the size of tumor (p = 0.039), depth of invasion (p = 0.039), lymph node metastasis (p = 0.044), distant metastasis (p = 0.003), TNM stage (p = 0.030), and survival rate (p = 0.010). Further, Cox multivariates analysis indicated that G6PD expression level was an independent prognostic factor for patients after radical resection (p = 0.013). In conclusion, overexpression of G6PD is closely related to progression of gastric cancer, and might be regarded as an independent predictor of poor prognosis for gastric cancer.     

Overexpression of the centrosomal protein Aurora-A kinase is associated with poor prognosis in epithelial ovarian cancer patients.

PURPOSE: To assess the clinical significance of Aurora-A kinase, a centrosome-regulating serine-threonine kinase, in ovarian carcinoma. EXPERIMENTAL DESIGN: Aurora-A kinase expression was assessed by Western blot (cell lines) or immunohistochemistry (high-grade epithelial ovarian cancers), and clinical variables were collected by retrospective chart review. Centrosome amplification was assessed by immunofluorescence in cell lines, and by immunohistochemistry in patient samples. RESULTS: All ovarian cancer cell lines exhibited significant Aurora-A kinase protein overexpression, and all except A2780-par had centrosome amplification, a characteristic of mitotic dysregulation leading to genomic instability. Fifty-eight of 70 patient samples (82.8%) exhibited Aurora-A kinase overexpression compared with normal ovarian surface epithelium. High Aurora-A kinase expression was strongly associated with supernumerary centrosome count in tumor cells (P<0.001). Tumors with the greatest Aurora-A overexpression (n=24) had decreased patient survival (median survival, 1.44 versus 2.81 years; P=0.01). High Aurora-A expression and suboptimal surgical cytoreduction remained predictors of poor survival (P<0.05) by multivariate analysis. CONCLUSIONS: Aurora-A kinase is overexpressed by a substantial proportion of ovarian cancers and is associated with centrosome amplification and poor survival. It may be a useful prognostic marker and target in ovarian cancer.     

Overexpression of TMPRSS4 in non-small cell lung cancer is associated with poor prognosis in patients with squamous histology

Background:

Mortality rates in lung cancer patients have not decreased significantly in recent years, even with the implementation of new therapeutic regimens. One of the main problems is that a large proportion of patients present local or distant metastasis at the time of diagnosis. The need for identification of novel biomarkers and therapeutic targets for a more effective management of lung cancer led us to investigate TMPRSS4, a protease reported to promote tumour growth and metastasis.

Material and methods:

In all, 34 lung cancer cell lines were used to evaluate the TMPRSS4 expression. Cell migration and clonogenic assays, and an in-vivo lung metastasis model were used for functional analysis of the TMPRSS4 downregulation in H358, H441 and H2170 cell lines. The TMPRSS4 expression analysis in normal and malignant lung tissue samples was performed by qPCR. Five different microarray-based publicly available expression databases were used to validate our results and to study prognosis.

Results:

The TMPRSS4 knock down in H358, H441 and H2170 cells resulted in a significant reduction in proliferation, clonogenic capacity and invasion. A significant (P<0.05) decrease in the lung colonisation and growth was found when mice were injected with TMPRSS4-depleated H358-derived clones, as compared with controls. Expression of TMPRSS4 showed a >30-fold increase (P<0.001) in tumours in comparison with non-malignant samples. Levels in tumours with squamous cell carcinoma (SCC) histology were found to be significantly higher (P<0.001) than those with adenocarcinoma (AC) histology, which was confirmed in data retrieved from the microarrays. Kaplan–Meier curves demonstrated that high levels of TMPRSS4 were significantly associated (P=0.017) with reduced overall survival in the patients with SCC histology, whereas no correlation was found for the AC histology.

Conclusion:

Our results demonstrate that TMPRSS4 has a role in the lung cancer development. The potential use of TMPRSS4 as a biomarker for lung cancer detection or as a predictor of patient''s outcome warrants further investigation.     

Decreased Muc5AC expression is associated with poor prognosis in gastric cancer

Mucins reportedly play numerous key roles in carcinogenesis, including in tumor invasion, regulation of differentiation and tumor cell proliferation. We investigated the effect of Muc5AC, a secreted mucin, on the invasiveness/migratory capability of gastric cancer cells and the prognostic significance of Muc5AC in gastric cancer patients. The clinicopathological and prognostic significance of Muc5AC expression was validated using immunohistochemical analysis in 412 gastric cancer patients. Differential gene expression was investigated using complementary DNA microarray analysis of 48 fresh tumor tissue samples. Silencing of Muc5AC by using a small hairpin RNA‐containing lentivirus increased the invasion and migration of SNU216 and AGS cells as well as Akt phosphorylation and the expression of vascular endothelial growth factor and matrix metalloproteinase‐7, which were blocked by inhibitors of the phosphatidylinositol 3‐kinase/Akt pathway. Loss of Muc5AC expression was significantly associated with tumor progression (advanced T stage; p = 0.004), lymph node metastases (p = 0.001), lymphovascular invasion (p < 0.0001), and increased tumor size (p = 0.027). Lower MUC5AC expression was identified as an independent poor prognostic factor in diffuse‐type gastric cancer by using the Cox regression proportional hazard model (hazard ratio, 2.39; p = 0.043). Complementary DNA microarray analysis revealed 86 differentially expressed genes, including genes related to metastasis and invasion, in gastric cancer tissues with high (≥25%) and low (<25%) Muc5AC expression levels. Low Muc5AC expression increased the invasion and migration of gastric cancer cells and could be a useful biomarker of poor prognosis in gastric cancer.     

Cyclin E amplification/overexpression is associated with poor prognosis in gastric cancer

We describe the correlation between cyclin E and HER2 amplification/overexpression and the clinical outcome in 87 patients with gastric cancer (GC) treated with surgery and adjuvant treatment at our centre. We observed that cyclin E and HER2 amplification/overexpression are not mutually exclusive, and that cyclin E amplification/overexpression correlates with poor prognosis. The co-amplification of cyclin E and HER2 in GC warrants prospective evaluation given the reported role of cyclin E in limiting the effectiveness of anti-HER2 therapies.     

High expressions of galectin-1 and VEGF are associated with poor prognosis in gastric cancer patients

High expressions of galectin-1 and vascular endothelial growth factor (VEGF) are correlated with biological behavior in some cancers. The aim of this study is to evaluate the expressions of galectin-1 and VEGF in gastric cancer and investigate their relationships with clinicopathological factors and prognostic significance. Immunohistochemical analyses for galectin-1 and VEGF expression were performed on 108 cases of gastric cancer. The relationship between the expression and staining intensity of galectin-1 and VEGF, clinicopathological variables, and survival rates was analyzed. Immunohistochemical staining demonstrated that 68 of 108 gastric cancer samples (63.0 %) were positive for galectin-1 and 62 out of 108 gastric cancer samples (57.4 %) were positive for VEGF. Galectin-1 expression was associated with tumor size, differentiation grade, TNM stage, lymph node metastases, and VEGF expression. VEGF expression was related to tumor size, TNM stage, and lymph node metastases. Kaplan–Meier survival analysis showed that high galectin-1 and VEGF expressions exhibited significant correlations with poor prognosis for gastric cancer patients. Multivariate analysis revealed that galectin-1 and VEGF expressions were independent prognostic parameters for the overall survival rate of gastric cancer patients. The results of the present study suggest that galectin-1 expression is positively associated with VEGF expression. Both galectin-1 and VEGF can serve as independent prognostic indicators of poor survival for gastric cancer.