Gastric cancer

Prognostic impact and immunotherapeutic implications of NETosis-related gene signature in gastric cancer patients

The role of NETosis and its related molecules remains unclear in gastric cancer. The data used in this study was directly downloaded from the Cancer Genome Atlas (TCGA) database. All analysis and plots are completed in R software using diverse R packages. In our study, we collected the list of NETosis-related genes from previous publications. Based on the list and expression profile of gastric cancer patients from the TCGA database, we identified the NETosis-related genes significantly correlated with patients survival. Then, CLEC6A, BST1 and TLR7 were identified through LASSO regression and multivariate Cox regression analysis for prognosis model construction. This prognosis model showed great predictive efficiency in both training and validation cohorts. We noticed that the high-risk patients might have a worse survival performance. Next, we explored the biological enrichment difference between high- and low-risk patients and found that many carcinogenic pathways were upregulated in the high-risk patients. Meanwhile, we investigated the genomic instability, mutation burden and immune microenvironment difference between high- and low-risk patients. Moreover, we noticed that low-risk patients were more sensitive to immunotherapy (85.95% vs. 56.22%). High-risk patients were more sensitive to some small molecules compounds like camptothecin_1003, cisplatin_1005, cytarabine_1006, nutlin-3a (-)_1047, gemcitabine_1190, WZ4003_1614, selumetinib_1736 and mitoxantrone_1810. In summary, our study comprehensively explored the role of NETosis-related genes in gastric cancer, which can provide direction for relevant studies.

Nuclear translocation of cleaved PCDH9 impairs gastric cancer metastasis by downregulating CDH2 expression

Loss of Protocadherin 9 (PCDH9) is associated with the metastasis and the prognosis of gastric cancer patients, while the molecular mechanism of PCDH9-impaired gastric cancer metastasis remains unclear. Here we show that PCDH9 is cleaved in gastric cancer cells. Intracellular domain of PCDH9 translocates into nucleus, where it interacts with DNA methyltransferase 1 (DNMT1) and increases DNMT1 activity. Activated DNMT1 downregulates cadherin 2 (CDH2) expression by increasing DNA methylation at its promoter, thereby dampening the migration and in vivo metastasis of gastric cancer cells. In addition, the levels of nuclear PCDH9 correlate with CDH2 expression, lymph node metastasis, and the prognosis of gastric cancer patients. Our finding demonstrates a unique mechanism of nuclear PCDH9-impaired gastric cancer metastasis by promoting DNA methylation of CDH2 promoter.

Construction of iron metabolism-related prognostic features of gastric cancer based on RNA sequencing and TCGA database

BACKGROUND

Researches have manifested that the disorder of iron metabolism is participated in Gastric cancer (GC), but whether iron metabolism-relevant genes (IMRGs) is related to the survival outcome of GC remain unknown.

METHODS

Eleven tumor as well as nine adjacent normal tissues from GC patients were underwent mRNA sequencing, and the The Cancer Genome Atlas Stomach Cancer (TCGA-STAD) datasets were acquired from the TCGA database. Cox analyses and least absolute shrinkage and selection operator (LASSO) regression were applied to build a IMRGs signature. The relationship between signature genes and the infiltration profiling of 24 immune cells were investigated using single-sample GSEA (ssGSEA). Meanwhile, the potential biological significance, genes that act synergistically with signature genes, and the upstream regulatory targets were predicted. Finally, the abundance of the signature genes were measured via the quantitative real-time PCR (qRT-PCR).

RESULTS

A IMRGs signature was constructed according to the expression and corresponding coefficient of DOHH, P4HA3 and MMP1 (The Schoenfeld individual test showed risk score was not significant with P values = 0.83). The prognostic outcome of patients in the high-risk group was terrible (p < 0.05). Receiver operating characteristic (ROC) curves confirmed that the IMRGs signature presented good efficiency for predicting GC prognosis (AUC > 0.6). The nomogram was performed well for clinical utilize (C-index = 0.60), and the MMP1 expression significantly increased in the cohorts at age > 60 and Stage II-IV (p < 0.05). The positive correlation of P4HA3 and MMP1 expression as well as the negative correlation of DOHH expression with risk score (p < 0.0001) and worse prognosis (p < 0.05) were detected as well. Furthermore, 11 differential immune cells were associated with these signature genes (most p < 0.01). Finally, qRT-PCR revealed that the abundance of DOHH, P4HA3 and MMP1 were high in tumor cases, indicating the complex mechanism between the high expression of DOHH as a protective factor and the high expression of P4HA3 and MMP1 as the risk factors in the development of GC.

CONCLUSION

An iron metabolism-related signature was constructed and has significant values for foretelling the OS of GC.

Identification of a novel reactive oxygen species (ROS)-related genes model combined with RT-qPCR experiments for prognosis and immunotherapy in gastric cancer

Reactive oxygen species play a crucial role in the prognosis and tumor microenvironment (TME) of malignant tumors. An ROS-related signature was constructed in gastric cancer (GC) samples from TCGA database. ROS-related genes were obtained from the Molecular Signatures Database. Consensus clustering was used to establish distinct ROS-related subtypes related to different survival and immune cell infiltration patterns. Sequentially, prognostic genes were identified in the ROS-related subtypes, which were used to identify a stable ROS-related signature that predicted the prognosis of GC. Correlation analysis revealed the significance of immune cell iniltration, immunotherapy, and drug sensitivity in gastric cancers with different risks. The putative molecular mechanisms of the different gastric cancer risks were revealed by functional enrichment analysis. A robust nomogram was established to predict the outcome of each gastric cancer. Finally, we verified the expression of the genes involved in the model using RT-qPCR. In conclusion, the ROS-related signature in this study is a novel and stable biomarker associated with TME and immunotherapy responses.

Comprehensive Analysis Based on the Cancer Immunotherapy and Immune Activation of Gastric Cancer Patients

When it comes to aggressiveness and prognosis, immune cells play an important role in the microenvironment of gastric cancer (GC). Currently, there is no well-established evidence that immune status typing is reliable as a prognostic tool for gastric cancer. This study aimed to develop a genetic signature based on immune status typing for the stratification of gastric cancer risk. TCGA data were used for gene expression and clinical characteristics analysis. A ssGSEA algorithm was applied to type the gastric cancer cohorts. A multivariate and univariate Cox regression and a lasso regression were conducted to determine which genes are associated with gastric cancer prognosis. Finally, we were able to produce a 6-gene prognostic prediction model using immune-related genes. Further analysis revealed that the prognostic prediction model is closely related to the prognosis of patients with GC. Nomograms incorporating genetic signatures and risk factors produced better calibration results. The relationship between the risk score and gastric cancer T stage was also significantly correlated with multiple immune markers related to specific immune cell subsets. According to these results, patients' outcomes and tumor immune cell infiltration correlate with risk scores. In addition, immune cellular-based genetic signatures can contribute to improved risk stratification for gastric cancer. Clinical decisions regarding immunotherapy and followup can be guided by these features.

HMMR promotes peritoneal implantation of gastric cancer by increasing cell-cell interactions

BACKGROUND

Distant metastasis is the prominent factor for cancer-induced death of gastric cancer in which peritoneum is one of the dominating targets of gastric cancer metastasis. However, there is still a lack of effective predictive indicators and treatment methods for gastric cancer patients with peritoneal metastasis.

METHODS

A clustering assay was used to investigate the cell aggregates formation ability. While the soft agar assay and anoikis assay were performed to detect the anchorage-independent growth and anoikis-resistant ability respectively. Luciferase activity assay, western blotting and immunofluorescence were used to explore the effect of HMMR on AKT signaling activity. The peritoneal implantation model was examined to explore the role of HMMR in vivo.

RESULTS

Silencing of HMMR expression markedly reduced the peritoneal metastasis of gastric cancer cells through reducing cell-cell interactions. Mechanistically, HA-HMMR could activate Akt signaling, thus succeeding in distant colonization and metastatic outgrowth. Importantly, inducible depletion of HMMR significantly abrogates peritoneal implantation of gastric cancer in vitro and in vivo.

CONCLUSION

Our study highlights that HMMR promotes peritoneal implantation of gastric cancer. A better understanding of HMMR's functions and mechanism might provide a novel therapeutic target and prognostic marker for metastatic gastric cancer.

Quantitative Dynamic-Enhanced MRI and Intravoxel Incoherent Motion Diffusion-Weighted Imaging for Prediction of the Pathological Response to Neoadjuvant Chemotherapy and the Prognosis in Locally Advanced Gastric Cancer

Background

This study aimed to explore the predictive value of quantitative dynamic contrast-enhanced MRI (DCE-MRI) and intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) quantitative parameters for the response to neoadjuvant chemotherapy (NCT) in locally advanced gastric cancer (LAGC) patients, and the relationship between the prediction results and patients’ prognosis, so as to provide a basis for clinical individualized precision treatment.

Methods

One hundred twenty-nine newly diagnosed LAGC patients who underwent IVIM-DWI and DCE-MRI pretreatment were enrolled in this study. Pathological tumor regression grade (TRG) served as the reference standard of NCT response evaluation. The differences in DCE-MRI and IVIM-DWI parameters between pathological responders (pR) and pathological non-responders (pNR) groups were analyzed. Univariate and multivariate logistic regressions were used to identify independent predictive parameters for NCT response. Prediction models were built with statistically significant quantitative parameters and their combinations. The performance of these quantitative parameters and models was evaluated using receiver operating characteristic (ROC) analysis. Clinicopathological variables, DCE-MRI and IVIM-DWI derived parameters, as well as the prediction model were analyzed in relation to 2-year recurrence-free survival (RFS) by using Cox proportional hazards model. RFS was compared using the Kaplan–Meier method and the log-rank test.

Results

Sixty-nine patients were classified as pR and 60 were pNR. K^trans, k_ep, and v_e values in the pR group were significantly higher, while ADC_standard and D values were significantly lower than those in the pNR group. Multivariate logistic regression analysis demonstrated that K^trans, k_ep, v_e, and D values were independent predictors for NCT response. The combined predictive model, which consisted of DCE-MRI and IVIM-DWI, showed the best prediction performance with an area under the curve (AUC) of 0.922. Multivariate Cox regression analysis showed that ypStage III and NCT response predicted by the IVIM-DWI model were independent predictors of poor RFS. The IVIM-DWI model could significantly stratify median RFS (52 vs. 15 months) and 2-year RFS rate (72.3% vs. 21.8%) of LAGC.

Conclusion

Pretreatment DCE-MRI quantitative parameters K^trans, k_ep, v_e, and IVIM-DWI parameter D value were independent predictors of NCT response for LAGC patients. The regression model based on baseline DCE-MRI, IVIM-DWI, and their combination could help RFS stratification of LAGC patients.

BET protein inhibitor JQ1 downregulates chromatin accessibility and suppresses metastasis of gastric cancer via inactivating RUNX2/NID1 signaling

Chromatin accessibility is critical for tumor development, whose mechanisms remain unclear. As a crucial regulator for chromatin remodeling, BRD4 promotes tumor progression by regulating multiple genes. As a small-molecule inhibitor of BRD4, JQ1 has potent chemotherapeutic activity against various human cancers. However, whether JQ1 has potential anti-tumor effects and how JQ1 regulates global transcription in gastric cancer (GC) remain largely unknown. In this research, we found BRD4 was highly expressed in GC tissues and was significantly associated with poor prognosis. JQ1 inhibited the proliferation and induced apoptosis of GC cells in vitro. Besides, JQ1 suppressed the migration and invasion of cancer cells by inducing MET. Notably, an assay for transposase-accessible chromatin using sequencing (ATAC-seq) data showed that JQ1 obviously downregulated the chromatin accessibility of GC cells and differentially accessible regions were highly enriched for RUNX2-binding motifs. Combinational analysis of ATAC-seq and RNA-seq data discovered NID1 as the downstream target of JQ1 and JQ1 reduced NID1 expression in GC cells. Chromatin immunoprecipitation, luciferase reporter gene assay, and rescue experiments all confirmed that RUNX2/NID1 axis was responsible for JQ1-inhibiting metastasis of GC cells. What’s more, high expression of NID1 in GC tissues also predicted poor survival outcome of cancer patients and NID1 knockdown prohibited migration and invasion of cancer cells via partially inducing MET. Finally, in vivo models showed that JQ1 prevented GC growth and suppressed cancer metastasis. In conclusion, JQ1 inhibits the malignant progression of GC by downregulating chromatin accessibility and inactivating RUNX2/NID1 signaling. In addition, NID1 is also a novel therapeutic target for progressive GC patients.

The use of DNA repair genes as prognostic indicators of gastric cancer

DNA repair genes can be used as prognostic biomarkers in many types of cancer. We aimed to identify prognostic DNA repair genes in patients with gastric cancer (GC) by systematically bioinformatic approaches using web-based database. Global gene expression profiles from altogether 1,325 GC patients' samples from six independent datasets were included in the study. Clustering analysis was performed to screen potentially abnormal DNA repair genes related to the prognosis of GC, followed by unsupervised clustering analysis to identify molecular subtypes of GC. Characteristics and prognosis differences were analyzed among these molecular subtypes, and modular key genes in molecular subtypes were identified based on changes in expression correlation. Multivariate Cox proportional hazard analysis was used to find the independent prognostic gene. Kaplan-Meier method and log-rank test was used to estimate correlations of key DNA repair genes with GC patients'overall survival. There were 57 key genes significantly associated to GC patients' prognosis, and patients were stratified into three molecular clusters based on their expression profiles, in which patients in Cluster 3 showed the best survival (P < 0.05). After a three-phase training, test and validation process, the expression profile of 13 independent key DNA repair genes were identified can classify the prognostic risk of patients. Compared with patients with low-risk score, patients with high risk score in the training set had shorter overall survival (P < 0.0001). Furthermore, we verified equivalent findings by these key DNA repair genes in the test set (P < 0.0001) and the independent validation set (P = 0.0024). Our results suggest a great potential for the use of DNA repair gene profiling as a powerful marker in prognostication and inform treatment decisions for GC patients.

Increased musashi 2 expression indicates a poor prognosis and promotes malignant phenotypes in gastric cancer

Musashi 2 (MSI2), a marker of stem and progenitor cells, has been identified as an oncogene. Various investigations have revealed that MSI2 is differently expressed in several types of blood cancer and solid cancers. However, its expression and biological functions in gastric cancer (GC) remain unclear. In the present study, MSI2 mRNA and protein expression were assessed in GC tissue samples. The associations between MSI2 mRNA expression and the clinicopathological characteristics of patients with GC were analyzed, and the effect of MSI2 on the prognosis of patients with GC was verified. The biological functions of MSI2 in GC cells were assessed using gain-of-function assays in vitro. The results revealed that MSI2 was overexpressed in the majority of GC tissue samples, although this difference was not significant. MSI2 mRNA expression levels were associated with invasion depth, tumor-node-metastasis stage, degree of differentiation and tumor size (P<0.05), but were not associated with sex, age, tumor location or human epidermal growth factor receptor 2 expression. Increased MSI2 expression resulted in a poorer prognosis in patients with GC (χ²=4.221; P=0.040). In vitro assays revealed that MSI2 promoted MKN-28 cell proliferation, migration and invasion, and promoted tube formation in HUVECs. Although no significance of MSI2 expression was found, its oncogenic functions in the GC cell line indicated that MSI2 may be a potential oncogene that may serve as a biomarker for GC diagnosis and prognosis with verification from a larger sample and more GC cell lines.

Identification and validation of a prognostic 9-genes expression signature for gastric cancer

Gastric cancer (GC) is a common malignant tumor with high incidence and mortality. Reasonable assessment of prognosis is essential to improve the outcomes of patients. In this study, we constructed and validated a prognostic gene model to evaluate the risks of GC patients. To identify the differentially expressed genes between GC patients and controls, we extracted Gene expression profiles of GC patients (N=432) from Gene Expression Omnibus database and then stable signature genes by using Robust likelihood-based modeling with 1000 iterations. Unsupervised hierarchical clustering of all samples was performed basing on the characteristics of gene expressions. Meanwhile, the differences between the clusters were analyzed by Kaplan Meier survival analysis. A 9-genes model was obtained (frequency = 999; p=1.333628e^-18), including two negative impact factors (NR1I2 and LGALSL) and 7 positive ones (C1ORF198, CST2, LAMP5, FOXS1, CES1P1, MMP7 and COL8A1). This model was verified in single factor survival analysis (p=0.004447558) and significant analysis with recurrence time (p=0.001474831) by using independent datasets from TCGA. The constructed 9-genes model was stable and effective, which might serve as prognostic signature to predict the survival of GC patients and monitor the long-term treatment of GC.

SUMO-1 Gene Silencing Inhibits Proliferation and Promotes Apoptosis of Human Gastric Cancer SGC-7901 Cells

Background: It has been reported that blocking small ubiquitin-like modifier (SUMO) conjugation by silencing SUMO gene remarkably decreased tumor growth in vivo. However, few studies have examined the relationship between SUMO gene silencing and gastric cancer (GC). The study aims to explore the effects of SUMO-1 gene silencing on GC cell proliferation and apoptosis. Methods: GC cells were cultured and divided into 5 groups: the blank group (without any transfection or treatment), the empty vector group (transfected with empty vector), the shRNA-SUMO-1-1 group (transfected with shRNA-SUMO-1-1 plasmid), the shRNA-SUMO-1-2 group (transfected with shRNA-SUMO-1-2 plasmid), and the shRNA-SUMO-1-3 group (transfected with shRNA-SUMO-1-3 plasmid). Cell Counting Kit-8 (CCK-8) assay was performed to examine cell proliferation. Annexin V/PI staining combined with flow cytometry were used to detect cell apoptosis. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were employed to measure the mRNA and protein expressions of SUMO-1, P53, Bcl-2 and c-myc, respectively. Results: SUMO-1 mRNA and protein expressions were decreased after transfecting with shRNA-SUMO-1. Compared with the blank group, the shRNA-SUMO-1-1 group presented a remarkable decreased proliferation of SGC-7901 cells. Significant increase in cell apoptosis rate was observed. Bcl-2, c-myc and P53 expressions were declined after transfecting with shRNA-SUMO plasmid. Conclusion: Our study provided evidence that SUMO-1 gene silencing could decrease proliferation and promote apoptosis in GC cells.

Impact of clinicopathological parameters on survival after multiorgan resection among patients with T4 gastric carcinoma: a systematic review and meta-analysis

BACKGROUND

The prognostic factors which can improve the overall survival (OS) of patients with T4 gastric carcinoma (GC) are still controversial: a meta-analysis was conducted to analyze the impact of clinicopathological parameters on survival after MOR among patients with T4 GC.

METHODS

A systematic search was performed. Odd risks (ORs) of patients with T4 GC were used to calculate the relationship between clinicopathological parameters and OS.

RESULTS

Nine studies involving 941 patients with T4 GC were identified. Well-moderate differentiation led to increased 1-, 3-, 5-year OS with an OR of 2.63, 1.58 and 1.45. Borrmann type I-II led to increased 1-, 3-year OS with an OR of 1.67 and 2.08. No lymph node metastasis led to increased 1-, 3-, 5-year OS with an OR of 7.16, 3.18 and 3.71. Total gastrectomy led to increased 1-, 3-year OS with an OR of 2.01 and 1.79. ≥2 Organs resected led to increased 1-, 3-year OS with an OR of 2.19 and 2.19. TNM stage II-III led to increased 1-, 3-year OS with an OR of 3.68 and 5.75. Curative resection led to increased 1-, 3-, 5-year OS with an OR of 4.46, 5.80 and 5.98.

CONCLUSION

Well-moderate differentiation, Borrmann type I-II, no lymph node metastasis, total gastrectomy, ≥2 organs resected, TNM stage II-III and curative resection were positive prognostic factors for OS of patients with T4 GC.

The expression of metastasis-associated in colon cancer-1 and KAI1 in gastric adenocarcinoma and their clinical significance

Background

The most common reason for malignant tumor treatment failure is recurrence and metastasis. Metastasis-associated in colon cancer-1 (MACC1) was originally identified as a metastatic and prognostic biomarker for colon cancer and later other solid tumors. Kangai 1 (KAI1), a marker of suppressor of metastasis, is also associated with metastasis and poor prognosis in many tumors. However, the prognostic value of either MACC1 or KAI1 in gastric adenocarcinoma (GAC) is unclear. In this study, we explored the relationship between MACC1 and KAI1 expression, as well as their respective correlation with clinicopathological features, to determine if either could be helpful for improvement of survival prognosis in GAC patients.

Methods

The expression levels of both MACC1 and KAI1 in 325 whole-tissue sections of GAC were examined by immunohistochemistry. Clinical data was also collected.

Results

MACC1 was significantly overexpressed in GAC tissues when compared to levels in normal gastric tissues; KAI1 was significantly down-expressed in GAC tissues when compared to levels in normal gastric tissues. Investigation of association between MACC1 and KAI1 protein levels with clinicopathological parameters of GAC indicated association between the expression of each with tumor grade, lymph node metastasis, invasive depth, and TNM stages. The overall survival time of patients with MACC1- or KAI1-positive GAC tumors was significantly shorter or longer than that of those who were negative. Importantly, multivariate analysis suggested that positive expression of either MACC1 or KAI1, as well as TNM stage, could be independent prognostic factors for overall survival in patients with GAC.

Conclusions

MACC1 and KAI1 may represent promising metastatic and prognostic biomarkers, as well as potential therapeutic targets, for GAC.

BET inhibition as a new strategy for the treatment of gastric cancer

Gastric cancer is one of the most common malignancies and a leading cause of cancer death worldwide. The prognosis of stomach cancer is generally poor as this cancer is not very sensitive to commonly used chemotherapies. Epigenetic modifications play a key role in gastric cancer and contribute to the development and progression of this malignancy. In order to explore new treatment options in this target area we have screened a library of epigenetic inhibitors against gastric cancer cell lines and identified inhibitors for the BET family of bromodomains as potent inhibitors of gastric cancer cell proliferations. Here we show that both the pan-BET inhibitor (+)-JQ1 as well as a newly developed specific isoxazole inhibitor, PNZ5, showed potent inhibition of gastric cancer cell growth. Intriguingly, we found differences in the antiproliferative response between gastric cancer cells tested derived from Brazilian patients as compared to those from Asian patients, the latter being largely resistant to BET inhibition. As BET inhibitors are entering clinical trials these findings provide the first starting point for future therapies targeting gastric cancer.

Tissue Inhibitor of Metalloproteinase-1 Is Confined to Tumor-Associated Myofibroblasts and Is Increased With Progression in Gastric Adenocarcinoma

The tissue inhibitor of metalloproteinase-1 (TIMP-1) inhibits the extracellular matrix-degrading activity of several matrix metalloproteinases, thereby regulating cancer cell invasion and metastasis. Studies describing the expression pattern and cellular localization of TIMP-1 in gastric cancer are, however, highly discordant. We addressed these inconsistencies by performing immunohistochemistry and in situ hybridization analyses in a set of 49 gastric cancer lesions to reexamine the TIMP-1 localization. In addition, we correlated these findings to clinicopathological parameters. We show that strong expression of TIMP-1 protein and mRNA was observed in a subpopulation of stromal fibroblast-like cells at the periphery of the cancer lesions. In a few cases, a small fraction of cancer cells showed weak expression of TIMP-1 protein and mRNA. The stromal TIMP-1-expressing cells were mainly tumor-associated myofibroblasts. In the normal-appearing mucosa, scattered TIMP-1 protein was only found in chromogranin A positive cells. TIMP-1-positive myofibroblasts at the invasive front of the tumors were more frequently seen in intestinal than in diffuse histological subtype cases (p=0.009). A significant trend to a higher number of cases showing TIMP-1 staining in myofibroblasts with increasing tumor, node, metastasis (TNM) stage was also revealed (p=0.041). In conclusion, tumor-associated myofibroblasts are the main source of increased TIMP-1 expression in gastric cancer.

Prognostic Significance of Tag SNP rs1045411 in HMGB1 of the Aggressive Gastric Cancer in a Chinese Population

Compelling evidences have suggested that high mobility group box-1 (HMGB1) gene plays a crucial role in cancer development and progression. This study aimed to evaluate the effects of single nucleotide polymorphisms (SNPs) in HMGB1 gene on the survival of gastric cancer (GC) patients. Three tag SNPs from HMGB1 gene were selected and genotyped using Sequenom iPEX genotyping system in a cohort of 1030 GC patients (704 in training set, 326 in validation set). Multivariate Cox proportional hazard model and Kaplan-Meier Curve were used for prognosis analysis. AG/AA genotypes of SNP rs1045411 in HMGB1 gene were significantly associated with better overall survival (OS) in a set of 704 GC patients when compared with GG genotypes (HR = 0.77, 95% CI: 0.60-0.97, P = 0.032). This prognostic effect was verified in an independent validation set and pooled analysis (HR = 0.80, 95% CI: 0.62-0.99, P = 0.046; HR = 0.78, 95% CI: 0.55-0.98, P = 0.043, respectively). In stratified analysis, the protective effect of rs1045411 AG/AA genotypes was more prominent in patients with adverse strata, compared with patients with favorable strata. Furthermore, strong joint predictive effects on OS of GC patients were noted between rs1045411 genotypes and Lauren classification, differentiation, stage or adjuvant chemotherapy. Additionally, functional assay indicated a significant effect of rs1045411 on HMGB1 expression. Our results suggest that rs1045411 in HMGB1 is significantly associated with clinical outcomes of Chinese GC patients after surgery, especially in those with aggressive status, which warrants further validation in other ethnic populations.

The anthelmintic drug mebendazole inhibits growth, migration and invasion in gastric cancer cell model

The present study aimed to investigate the effects of MBZ on a human malignant ascites cell line derived from a primary gastric cancer tumor. Our data reveal that MBZ showed high cytotoxicity in vitro, displaying an IC50 of 0.39 μM and 1.25 μM in ACP-02 and ACP-03, respectively. The association between MBZ and 5-FU increased slightly the cytotoxicity when compared to MBZ and 5-FU alone. Furthermore, MBZ disrupted the microtubule structure of AGP-01 cells and inhibited significantly the invasion and migration of these cells. Activity of active MMP-2 significantly decreased at all tested concentration of MBZ compared to negative control. These results support the indication of MBZ in combination with chemotherapeutic agents as a possible adjuvant therapy for the management/treatment of patients with advanced gastric cancer since MBZ is a drug of low cost with acceptable safety profile and reduced toxicity to normal cells. However, clinical trials must be performed in o to evaluate its efficacy in gastric cancer patients.

Effects of stromal interacting molecule 1 gene silencing by short hairpin RNA on the biological behavior of human gastric cancer cells

Gastric cancer is one of the most common types of cancer worldwide. It has been reported that stromal interacting molecule 1 (STIM1) is associated with tumor progression and metastatic spread, including in cervical cancer, breast carcinoma and prostatic cancer. The present study investigated whether STIM1, an endoplasmic reticulum Ca(2+) sensor and activator of store-operated channel entry, contributed to SGC7901 cell progression. The pGPU6-shSTIM1 recombinant plasmid was constructed, and the effects of downregulation of STIM1 on the proliferation, apoptosis, migration and invasion of SGC7901 cells were examined. Western blot analysis revealed that transfection with the pGPU6-shSTIM1 plasmid successfully inhibited the expression of STIM1. STIM1 silencing in the gastric cancer cells significantly inhibited cell proliferation by arresting the cell cycle at the G0/G1 phase, and increasing the apoptotic rate following treatment of the SGC7901 cells with pGPU6-shSTIM1, indicated using an MTT cell viability assay and flow cytometery, respectively. As expected, STIM1 knock down also reduced the migration and invasion of the SGC7901 cells, demonstrated using a Transwell assay. The possible molecular mechanism involved the regulation of several signaling pathways involved in the biological behavior of cell survival, apoptosis, migration and metastasis. Together, these finding suggested that the expression of STIM1 is crucial for the proliferation and invasion of SGC7901 cells, providing a foundation for the development of novel type‑specific diagnostic strategies and treatments for gastric cancer.

The Serum Immunoglobulin G Glycosylation Signature of Gastric Cancer

Biomarkers may facilitate detection of gastric cancer at an earlier stage and reduce mortality. Here we sought to determine if the glycosylation profile of serum immunoglobulin G (IgG) could distinguish patients with non-atrophic gastritis (NAG), duodenal ulcer (DU) and gastric cancer (GC). Serum IgG was released and analyzed using nano-LC-TOF mass spectrometry. Statistically significant false discovery rate (FDR)-adjusted p-values were observed for 18 glycans, eight that differed significantly between NAG and GC, three that distinguished NAG from DU, and eight that differed between DU and GC. The IgG glycosylation signature may be useful as a predictive marker for gastric cancer.

Circulating metastasis associated in colon cancer 1 transcripts in gastric cancer patient plasma as diagnostic and prognostic biomarker

AIM: To evaluate the diagnostic and prognostic value of circulating Metastasis Associated in Colon Cancer 1 (MACC1) transcripts in plasma of gastric cancer patients.

METHODS: We provide for the first time a blood-based assay for transcript quantification of the metastasis inducer MACC1 in a prospective study of gastric cancer patient plasma. MACC1 is a strong prognostic biomarker for tumor progression and metastasis in a variety of solid cancers. We conducted a study to define the diagnostic and prognostic power of MACC1 transcripts using 76 plasma samples from gastric cancer patients, either newly diagnosed with gastric cancer, newly diagnosed with metachronous metastasis of gastric cancer, as well as follow-up patients. Findings were controlled by using plasma samples from 54 tumor-free volunteers. Plasma was separated, RNA was isolated, and levels of MACC1 as well as S100A4 transcripts were determined by quantitative RT-PCR.

RESULTS: Based on the levels of circulating MACC1 transcripts in plasma we significantly discriminated tumor-free volunteers and gastric cancer patients (P < 0.001). Levels of circulating MACC1 transcripts were increased in gastric cancer patients of each disease stage, compared to tumor-free volunteers: patients with tumors without metastasis (P = 0.005), with synchronous metastasis (P = 0.002), with metachronous metastasis (P = 0.005), and patients during follow-up (P = 0.021). Sensitivity was 0.68 (95%CI: 0.45-0.85) and specificity was 0.89 (95%CI: 0.77-0.95), respectively. Importantly, gastric cancer patients with high circulating MACC1 transcript levels in plasma demonstrated significantly shorter survival when compared with patients demonstrating low MACC1 levels (P = 0.0015). Furthermore, gastric cancer patients with high circulating transcript levels of MACC1 as well as of S100A4 in plasma demonstrated significantly shorter survival when compared with patients demonstrating low levels of both biomarkers or with only one biomarker elevated (P = 0.001).

CONCLUSION: Levels of circulating MACC1 transcripts in plasma of gastric cancer patients are of diagnostic value and are prognostic for patient survival in a prospective study.

Serum glycan signatures of gastric cancer

Glycomics, a comprehensive study of glycans expressed in biologic systems, is emerging as a simple yet highly sensitive diagnostic tool for disease onset and progression. This study aimed to use glycomics to investigate glycan markers that would differentiate patients with gastric cancer from those with nonatrophic gastritis. Patients with duodenal ulcer were also included because they are thought to represent a biologically different response to infection with Helicobacter pylori, a bacterial infection that can cause either gastric cancer or duodenal ulcer. We collected 72 serum samples from patients in Mexico City that presented with nonatrophic gastritis, duodenal ulcer, or gastric cancer. N-glycans were released from serum samples using the generic method with PNGase F and were analyzed by matrix-assisted laser desorption/ionization Fourier transform-ion cyclotron resonance mass spectrometry. The corresponding glycan compositions were calculated based on accurate mass. ANOVA-based statistical analysis was performed to identify potential markers for each subgroup. Nineteen glycans were significantly different among the diagnostic groups. Generally, decreased levels of high-mannose-type glycans, glycans with one complex type antenna, bigalactosylated biantennary glycans, and increased levels of nongalactosylated biantennary glycans were observed in gastric cancer cases. Altered levels of serum glycans were also observed in duodenal ulcer, but differences were generally in the same direction as gastric cancer. Serum glycan profiles may provide biomarkers to differentiate gastric cancer cases from controls with nonatrophic gastritis. Further studies will be needed to validate these findings as biomarkers and identify the role of protein glycosylation in gastric cancer pathology.

Biomarkers of Helicobacter pylori-associated gastric cancer

Helicobacter pylori-associated gastric cancer is a major cause of morbidity and mortality worldwide, and is predicted to become even more common in developing countries as the population ages. Since gastric cancer develops slowly over years to decades, and typically progresses though a series of well-defined histologic stages, cancer biomarkers have potential to identify asymptomatic individuals in whom surgery might be curative, or even those for whom antibiotics to eradicate H. pylori could prevent neoplastic transformation. Here we describe some of the challenges of biomarker discovery, summarize current approaches to biomarkers of gastric cancer, and explore some recent novel strategies.

Prognostic role of microRNA polymorphisms in advanced gastric cancer: a translational study of the Arbeitsgemeinschaft Internistische Onkologie (AIO)

BACKGROUND

To determine the prognostic role of selected microRNA (miRNA) polymorphisms in advanced gastric cancer (AGC).

PATIENTS AND METHODS

Six hundred and seventy-four AGC patients received 5-fluorouracil (F), leucovorin (L), oxaliplatin (O) or FL + cisplatin (P) or additional docetaxel (T) to FLO (FLOT) within four clinical trials. Polymorphisms of mir-26a1 (rs7372209), mir-27a (rs895819), mir-100 (rs1834306), mir-146a (rs2910164), mir-196-a2 (rs11614913), mir-219-1 (rs107822) and mir-423 (rs6505162) were genotyped. Variable selection for the final multivariate model (n = 487) was based on univariate and multivariate Cox-regression analyses with a cut-off P-value of ≤ 20%.

RESULTS

Genetic factors significantly associated with overall survival (OS) were rs7372209 (mir-26a1) variant genotypes (hazard ratio, HR 1.307 [95% confidence interval (CI) 1.031-1.656], P = 0.0272), rs895819 (mir-27a) variant genotypes (HR 1.304 [95% CI 1.031-1.650], P = 0.0270) and rs11614913 (mir-196a2) variant genotypes (HR 0.791 [95% CI 0.625-1.000], P = 0.0497). Clinical factors with significant impact on OS were Eastern Cooperative Oncology Group (ECOG) 2 performance status (HR 1.880 [95% CI 1.254-2.820], P = 0.0023), curative surgery of advanced disease (HR 0.235 [95% CI 0.123-0.449], P < 0.0001) and addition of docetaxel in locally AGC patients (HR 0.348 [95% CI 0.145-0.838], P = 0.0301). Combined analyses revealed an improved OS in patients without any unfavourable genotype of 18 months compared with 14, 12 and 10 months in patients with 1, 2 and 3 unfavourable genotypes, respectively (P = 0.0257).

CONCLUSIONS

These data suggest a significant impact of selected miRNA polymorphisms on prognosis in AGC.

Irinotecan, leucovorin and 5-fluorouracil (modified FOLFIRI) as salvage chemotherapy for frail or elderly patients with advanced gastric cancer

We retrospectively evaluated the efficacy and safety of the modified FOLFIRI regimen in frail or elderly patients with advanced gastric cancer (AGC). We reviewed 24 frail [Eastern Cooperative Oncology Group performance status (ECOG PS) of 2] or elderly (65 years or over) patients with AGC who received the modified FOLFIRI regimen as salvage chemotherapy. Patients received irinotecan 150 mg/m(2) and leucovorin (LV) 100 mg/m(2) as a 2 h intravenous infusion, followed by 5-fluorouracil (5-FU) 2,000 mg/m(2) as a 46 h continuous infusion. Among the 24 patients, 18 (75%) had an ECOG PS of 2, and 11 (45.8%) were aged 65 years or over. A total of 113 cycles were conducted, with a median number of 4 cycles per patient. A total of 3 patients achieved partial response (PR) and 8 demonstrated stable disease (SD). On an intent-to-treat basis, the overall response rate (RR) was 12.5% and the disease control rate (PR and SD) was 45.8%. The median time to progression (TTP) was 2 months [95% confidence interval (CI), 1.9-2.1 months] and the median overall survival (OS) was 5.4 months (95% CI, 4.1-6.7 months). Grade 3-4 hematological toxicities, including neutropenia, anemia and thrombocytopenia, were observed in 6 (25%), 4 (16.7%) and 1 (4.2%) patients, respectively. Additionally, 3 (12.5%) patients developed febrile neutropenia, of which 1 succumbed to pneumonia. Grade 3-4 gastrointestinal toxicities, including nausea, vomiting, diarrhea and mucositis, were observed in 3 (12.5%), 2 (8.3%), 1 (4.2%) and 1 (4.2%) patients, respectively. In conclusion, the modified FOLFIRI regimen as salvage chemotherapy for AGC patients over 65 years of age or with a poor PS was effective and acceptable. These results suggest that this regimen may be an effective option for frail or elderly patients with AGC.

ZEB2 promotes the metastasis of gastric cancer and modulates epithelial mesenchymal transition of gastric cancer cells

BACKGROUND

Invasion and metastasis are the hallmarks of advanced gastric cancer progression. Therefore, it is urgent to overcome metastasis in order to improve the survival of gastric cancer patients.

AIMS

This study aimed to examine the expression of ZEB2 in gastric cancer samples and analyze its correlation with clinicopathologic features. In addition, the molecular mechanism by which ZEB2 contributes to gastric cancer metastasis will be explored.

METHODS

ZEB2 expression in clinical gastric cancer samples was evaluated by immunohistochemical analysis. ZEB2 was knocked-down in HGC27 gastric cancer cells by shRNA and the effects on cell invasion and migration were examined by in vitro cell invasion and migration assays. The expression of epithelial marker E-cadherin, mesenchymal markers fibronecin and vimentin, and MMPs was detected by western blot analysis.

RESULTS

The expression of ZEB2 was positively correlated with the depth of invasion, lymph node metastasis and TNM stage. In addition, patients with positive ZEB2 expression showed a significantly shorter overall survival time than did patients with negative ZEB2. shRNA mediated knockdown of ZEB2 resulted in reduced invasion and migration of HGC27 cells, along with the upregulation of E-cadherin and downregulation of fibronecin, vimentin, MMP2, and MMP9.

CONCLUSIONS

ZEB2 expression is closely associated with the clinicopathological parameters of gastric cancer. ZEB2 promotes gastric cancer cell migration and invasion at least partly via the regulation of epithelial-mesenchymal transition. ZEB2 is a potential target for gene therapy of aggressive gastric cancer.

Oxaliplatin, 5-fluorouracil and leucovorin (modified FOLFOX-6) as first-line chemotherapy for advanced gastric cancer patients with poor performance status

This study was designed to retrospectively evaluate the efficacy and safety of modified FOLFOX-6 regimen in advanced gastric cancer (AGC) patients with poor performance status (PS). From January 2005 to August 2010, 23 AGC patients with poor PS who received mFOLFOX-6 as first-line chemotherapy were reviewed. Patients received 100 mg/m(2) oxaliplatin and 100 mg/m(2) leucovorin (LV) as a 2-h intravenous infusion on day 1, followed by 5-fluorouracil (5-FU) at 2000 mg/m(2) as a 46-h continuous infusion. A total of 22 patients received more than 3 cycles of chemotherapy and were evaluable for tumor response. Seven patients achieved partial response, giving an overall response rate of 31.8%. The median time to progression and overall survival were 3.5 and 9.2 months, respectively. Grade 3-4 hematological toxicities were noted: neutropenia in four patients (17.4%), anemia in two (8.7%) and thrombocytopenia in one (4.3%). Two patients developed febrile neutropenia and one of these patients succumbed to sepsis. Grade 3-4 gastrointestinal toxicities, such as nausea, vomiting and diarrhea were observed in less than 10% of patients. Peripheral neuropathy was observed in 9 patients (39.1%). In conclusion, the mFOLFOX-6 regimen for AGC patients with poor PS was effective with acceptable toxicity. Our results suggest that this regimen may be an effective option for these patients.

Combination immunotherapy and active-specific tumor cell vaccination augments anti-cancer immunity in a mouse model of gastric cancer

Background

Active-specific immunotherapy used as an adjuvant therapeutic strategy is rather unexplored for cancers with poorly characterized tumor antigens like gastric cancer. The aim of this study was to augment a therapeutic immune response to a low immunogenic tumor cell line derived from a spontaneous gastric tumor of a CEA424-SV40 large T antigen (CEA424-SV40 TAg) transgenic mouse.

Methods

Mice were treated with a lymphodepleting dose of cyclophosphamide prior to reconstitution with syngeneic spleen cells and vaccination with a whole tumor cell vaccine combined with GM-CSF (a treatment strategy abbreviated as LRAST). Anti-tumor activity to subcutaneous tumor challenge was examined in a prophylactic as well as a therapeutic setting and compared to corresponding controls.

Results

LRAST enhances tumor-specific T cell responses and efficiently inhibits growth of subsequent transplanted tumor cells. In addition, LRAST tended to slow down growth of established tumors. The improved anti-tumor immune response was accompanied by a transient decrease in the frequency and absolute number of CD4⁺CD25⁺FoxP3⁺ T cells (Tregs).

Conclusions

Our data support the concept that whole tumor cell vaccination in a lymphodepleted and reconstituted host in combination with GM-CSF induces therapeutic tumor-specific T cells. However, the long-term efficacy of the treatment may be dampened by the recurrence of Tregs. Strategies to counteract suppressive immune mechanisms are required to further evaluate this therapeutic vaccination protocol.

Runx3 suppresses gastric cancer metastasis through inactivation of MMP9 by upregulation of TIMP-1

Recent studies have suggested that loss of RUNX3 expression is involved with gastric tumor metastasis. However, the precise mechanism of RUNX3-mediated suppression of tumor metastasis remains elusive. We aimed to clarify the effect of RUNX3 on tumor metastasis in gastric cancer cell lines and tumors. Immunohistochemistry revealed that RUNX3 was significantly decreased in metastatic gastric cancer. Gelatin zymography and Western blot showed that instead of regulating matrix metalloproteinase 9 (MMP9) expression, RUNX3 expression inhibited MMP9 enzyme activity, and this was consistent with the upregulation of tissue inhibitor of metalloproteinases 1 (TIMP1) by RUNX3. TIMP1 siRNA treatment impaired RUNX3-mediated suppression of gastric cancer cell invasion. Reporter assays demonstrated regulation of TIMP-1 by RUNX3. Two RUNX3 binding sites were identified in the TIMP-1 promoter and direct interaction of RUNX3 with the TIMP-1 promoter was confirmed in vitro and in vivo. These findings provide evidence for RUNX3-mediated suppression of gastric cancer invasion and metastasis and define a novel molecular mechanism that for the metastasis-inhibiting activity of RUNX3. These data may be applied in the development of RUNX3 for gastric cancer metastasis diagnostics and therapeutics.

Some early results related to electrical impedance of normal and abnormal gastric tissue

Gastric cancer is the fourth most common cancer and most patients with gastric cancer are being diagnosed in advanced stages of the disease so they do not gain any survival chance from conventional surgical, chemotherapeutic or radiotherapeutic methods. These are relatively high cost procedures in terms of both time and money. This study considers the introduction of a novel minimally invasive diagnostic technique which shows the relationship between histopathology and the electrical impedance spectrum in the human stomach. In this study, 4 electrode technique was used to differentiate tissues from each other using Tabriz Mark 1 electrical impedance system (30 different frequencies in the range of 2 kHz to 1 MHz). A total of 97 points from 45 patients were studied in terms of their biopsy reports matching to the electrical impedance measurements (in vivo). After impedance measurements and applying calibration factors, a non-parametric statistical technique, the Kruskal-Wallis test was used to evaluate the difference among the groups. According to the calculation of respective data using this spectroscopy system, the resistivity of the normal group was higher than that of the benign group, and the resistivity of these groups were higher than that of the malignant group at frequencies between 470 kHz and 1 MHz (P < 0.05). In these frequencies, the impedivity of the dysplastic tissue was significantly lower than that of the other groups (P < 0.05). Also, Cole equation fitting procedure was used to generate a scatter plot of the malignant and benign points: it shows in general, benign points had higher values of R than the malignant points. Therefore, electrical impedance spectroscopy can be a useful technique to characterize the stomach tissue.

Increasing the frequency of CIK cells adoptive immunotherapy may decrease risk of death in gastric cancer patients

AIM: To analyze the correlation between cytokine-induced killer (CIK) cells adoptive immunotherapy and cancer-related death in gastric cancer patients.

METHODS: One hundred and fifty-six gastric cancer patients after operation at the Third Affiliated Hospital of Soochow University were enrolled in this study. Their clinical data including demographic characteristics, operation time, tumor size, pathological type and staging, tumor metastasis, outcome of chemotherapy or CIK cells adoptive immunotherapy, survival time or time of death were collected with a standard structured questionnaire. Kaplan-Meier method was used to estimate the median survival time, and the 2- and 5- year survival rates. Hazard risk (HR) and 95% confidence interval (95% CI) of CIK cells adoptive immunotherapy for gastric cancer were calculated using the two-stage time-dependent covariates Cox model.

RESULTS: The survival time of gastric cancer patients was longer after CIK cells adoptive immunotherapy than after chemotherapy (χ² = 10.907, P = 0.001). The median survival time of gastric cancer patients was also longer after CIK cells adoptive immunotherapy than after chemotherapy (49 mo vs 27 mo, P < 0.05). The 2- and 5-year survival rates of gastric cancer patients were significantly higher after CIK cells adoptive immunotherapy than after chemotherapy (73.5% vs 52.6%, 40.4% vs 23.9%, P < 0.05). A significant difference was observed in the survival curve for patients who received CIK cells adoptive immunotherapy (0, 1-10, 11-25, and over 25 frequencies) (χ² = 14.534, P = 0.002). The frequencies of CIK cells adoptive immunotherapy were significantly related with the decreasing risk of death in gastric cancer patients after adjustment for sex and age of the patients, tumor stage and relapse (HR = 0.54, 95% CI: 0.36-0.80) when the first stage Cox model was used to define the subjects who remained alive beyond 36 mo as survivors. However, no correlation was observed between the frequencies of death in CIK cells adoptive immunotherapy and the risk of gastric cancer patients (HR = 1.09, 95% CI: 0.63-0.89) when the second stage Cox model was used to define the subjects who survived for more than 36 mo as survivors.

CONCLUSION: The survival time of the gastric cancer patients treated with chemotherapy combined with CIK cells adoptive immunotherapy is significantly longer than that of the patients treated with chemotherapy alone and increasing the frequency of CIK cells adoptive immunotherapy seems to benefit patients more.

Quantitative proteomics discloses MET expression in mitochondria as a direct target of MET kinase inhibitor in cancer cells

Cancer cells with MET overexpression are paradoxically more sensitive to MET inhibition than cells with baseline MET expression. The underlying molecular mechanisms are incompletely understood. Here, we have traced early responses of SNU5, a MET-overexpressing gastric cancer cell line, exposed to sublethal concentration of PHA-665752, a selective MET inhibitor, using iTRAQ-based quantitative proteomics. More than 1900 proteins were quantified, of which >800 proteins were quantified with at least five peptides. Proteins whose expression was perturbed by PHA-665752 included oxidoreductases, transfer/carrier proteins, and signaling proteins. Strikingly, 38% of proteins whose expression was confidently assessed to be perturbed by MET inhibition were mitochondrial proteins. Upon MET inhibition by a sublethal concentration of PHA-665752, mitochondrial membrane potential increased and mitochondrial permeability transition pore was inhibited concomitant with widespread changes in mitochondrial protein expression. We also showed the presence of highly activated MET in mitochondria, and striking suppression of MET activation by 50 nm PHA-665752. Taken together, our data indicate that mitochondria are a direct target of MET kinase inhibition, in addition to plasma membrane MET. Effects on activated MET in the mitochondria of cancer cells that are sensitive to MET inhibition might constitute a novel and critical noncanonical mechanism for the efficacy of MET-targeted therapeutics.

Expression of EphA2 and E-cadherin in gastric cancer: correlated with tumor progression and lymphogenous metastasis

In this study, gastric cancer progression was correlated with the over-expression of erythropoietin-producing hepatocellular (Eph)A2 receptor and down-expression of epithelial cadherin (E-cadherin). Immunohistochemistry of EphA2 and E-cadherin were performed on these tumor samples from 165 primary lesions of gastric cancer. The results showed that expression of EphA2 was obviously increased in gastric cancer tissues (P < 0.01), which was positively correlated with the depth of cancer invasion, tumor-node-metastasis (TNM) stage and lymph node metastasis (P < 0.05). Meanwhile, the expression of E-cadherin was significantly reduced (P < 0.01), which was negatively correlated with the depth of cancer invasion, grade of tumor differentiation, TNM stage and lymph node metastasis (P < 0.05). The correlation between EphA2 and E-cadherin expression was negative (r = -0.198, P = 0.011). In conclusion, either the over-expression of EphA2 or the down-expression of E-cadherin is correlated with cancer progression and lymphogenous metastasis in gastric cancer, suggesting that both of them may play an important role in tumor progression and metastasis.

Prognostic Factors of Patients With Transmural Advanced Gastric Carcinoma

Background

The purpose of this study is to evaluate perioperative morbidity, mortality and the prognostic factors that influence survival of the patients with transmural advanced gastric carcinoma after curative surgical therapy.

Methods

Fifty patients with transmural advanced gastric adenocarcinoma underwent curative resection in our clinic. The records of the patients were reviewed and the prognostic factors such as age, gender, location and size of the tumor, type of surgery, blood transfusion, depth of tumor invasion, lymph node metastases, stage of the disease, grading, vascular invasion, lymph vessel invasion, characteristics of the tumor according to Lauren’s classification, and lymph node ratio were evaluated by using statistical methods.

Results

In a total of 12 patients (24%) major morbidities developed, and five patients (10%) died. The overall survival rate was 48% at 1 year, 31% at 3 years, and 19% at 5 years. Lymph node metastases (P = 0.03), lymph vessel invasion (P = 0.001), blood transfusion (P = 0.021), and lymph node ratio (P = 0.006) were the prognostic features identified by univariate analysis. Among the multiple significant prognostic factors in the univariate analysis only one factor, lymph node ratio, proved to be independently significant in the multivariate analysis (RR: 4.47).

Conclusions

Our data showed that we can expect a good survival for patients with a lymph node ratio less than 0.2.

Over-expression of EphA2 and EphrinA-1 in human gastric adenocarcinoma and its prognostic value for postoperative patients

This study aims to investigate the expression and significance of EphA2 and EphrinA-1 in human gastric adenocarcinoma progression and prognosis. The expression of EphA2 and EphrinA-1 was detected in the cell lines and tissues of gastric adenocarcinoma. Different expression levels of EphA2 and EphrinA-1 were found in two cell lines. The expression of EphA2 and EphrinA-1 was significantly higher in gastric adenocarcinoma tissues than in normal tissues. Statistical analysis showed a significant correlation of EphA2 expression with the depth of tumor invasion, tumor-node-metastasis (TNM) stages, and lymph node metastasis. EphrinA-1 over-expression was significantly correlated with TNM stages and lymph node metastasis, while EphA2 expression was found to be an independent prognostic factor of postoperative gastric adenocarcinoma. In conclusion, the increased expression of EphA2 and EphrinA-1 plays an important role in the progression of human gastric adenocarcinoma, in which elevated EphA2 expression is an independent factor that indicates poor prognosis in postoperative gastric adenocarcinoma.

Association of cytotoxic T lymphocyte-associated antigen-4 gene haplotype with the susceptibility to gastric cancer

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) was widely accepted as a pivotal molecule in downregulating T-cell mediated immune responses. In this study we investigated the polymorphisms which would impact the CTLA-4 gene expression and function to assess the association with the risk of gastric cancer. 205 gastric cancer patients and 262 healthy controls were included in the case-control study. PCR and restriction fragment length polymorphism (RFLP) methods were performed to identify the +49A/G and promoter -1661A/G polymorphisms. The promoter -1772T/C polymorphism was detected by PCR amplification refractory mutation system (ARMS) technique. A significant difference was observed between case and control groups. The frequency of +49A/G polymorphism AG and -1661A/G polymorphism GG genotype were significantly higher in patients than in controls (OR = 2.15, OR = 1.88, respectively). No significant difference was found in the allelic frequency of -1772T/C polymorphism between cases and controls (P = 0.478). By the haplotype analysis, logistic regression showed the frequency of haplotype A (GAT) and D (AGT) in the case group revealed significant difference compared with in control group (OR = 2.00, P < 0.001; OR = 1.62, P = 0.043, respectively). Our findings implied the genetic variations within CTLA-4 gene would be a critical risk factor to the susceptibility of gastric cancer.

Sensitivity of ultrasonography for gastric cancer diagnosis in symptomatic patients

Endoscopy with biopsy sampling is the gold standard used in gastric cancer diagnosis. However, the positive predictive value of signs and symptoms for the diagnosis of carcinomas is quite limited, and, therefore, many patients are subjected to non-diagnostic endoscopies, especially when symptoms are not so specific. This study shows that ultrasonography is sensitive enough for the diagnosis of gastric cancer, and, therefore, use of this technique would further ensure a better selection of patients for endoscopy. The study included 143 patients (86 men and 57 women, with an average age of 68.6 years) who were suspected of having gastric cancer. The diagnostic accuracy of ultrasonography was evaluated in a blind study. The conventional technique was used in all cases. Demographic parameters and a series of other clinical-analytical variables were studied to look for possible gastric cancer predictive factors, which when present would make ultrasonographic results irrelevant. Statistical analysis was done using SPSS 12.0, wherein a value of P < 0.05 was considered to be statistically significant. Of the 143 patients studied, 40 were diagnosed to have gastric cancer. Sonography was able to diagnose 37 cases correctly, while there were three false negative findings and eight false positive findings. This results in 92.5% sensitivity, 92.2% specificity, 82.2% positive predictive value, 96.9% negative predictive value, and a global accuracy of 92.3%. Univariate analysis showed that persistent vomiting (P = 0.021), hemoglobin level of less than 8 g/dl (P = 0.045) and a positive ultrasonography result (P < 0.0001) were associated with a higher frequency of gastric cancer. Multivariate analysis showed that persistent vomiting, with an odds ratio for gastric cancer of 3.68 (95% confidence interval 1.15-11.79; P = 0.039), and a positive ultrasonography result, with an odds ratio for gastric cancer of 117.78 (95% confidence interval 32.45-427.49; P < 0.0001), could be considered as independent predictive factors for gastric cancer. It was concluded that ultrasonography is a very sensitive and specific technique for diagnosing gastric cancer. Gastric cancer was found to be present in just 28% of the patients studied, and their condition was suspect because of the clinical manifestations. Only vomiting and a positive ultrasonography result can be considered as independent predictive factors of gastric cancer.

Second-line chemotherapy for patients with advanced gastric cancer: who may benefit?

No established second-line chemotherapy is available for patients with advanced gastric cancer failing to respond or progressing to first-line chemotherapy. However, 20–40% of these patients commonly receive second-line chemotherapy. We evaluated the influence of clinico-pathologic factors on the survival of 175 advanced gastric cancer patients, who received second-line chemotherapy at three oncology departments. Univariate and multivariate analyses found five factors which were independently associated with poor overall survival: performance status 2 (hazard ratio (HR), 1.79; 95% CI, 1.16–2.77; P=0.008), haemoglobin ⩽11.5 g l⁻¹ (HR, 1.48; 95% CI, 1.06–2.05; P=0.019), CEA level >50 ng ml⁻¹ (HR, 1.86; 95% CI, 1.21–2.88; P=0.004), the presence of greater than or equal to three metastatic sites of disease (HR, 1.72; 95% CI, 1.16–2.53; P=0.006), and time-to-progression under first-line chemotherapy ⩽6 months (HR, 1.97; 95% CI, 1.39–2.80; P<0.0001). A prognostic index was constructed dividing patients into low- (no risk factor), intermediate- (one to two risk factors), or high- (three to five risk factors) risk groups, and median survival times for each group were 12.7 months, 7.1 months, and 3.3 months, respectively (P<0.001). In the absence of data deriving from randomised trials, this analysis suggests that some easily available clinical factors may help to select patients with advanced gastric cancer who could derive more benefit from second-line chemotherapy.

CTLA-4 gene promoter and exon 1 polymorphisms in Iranian patients with gastric and colorectal cancers

BACKGROUND AND AIM

Cytotoxic T-lymphocyte antigen-4 (CTLA-4) is a potent immunoregulatory molecule that suppresses antitumor response by down-regulating T-cell activation. Effects of several polymorphisms in CTLA-4 on CTLA-4 expression and function have been previously documented. The aim of this study was to investigate the putative effect of CTLA-4 polymorphisms on susceptibility to gastric and colorectal cancers in an Iranian population.

METHODS

A total of 155 patients (109 with colorectal cancer and 46 with gastric cancer) and 190 age- and sex-matched healthy controls were evaluated. Genotyping of -1722T/C, -1661A/G, and +49A/G were performed by PCR restriction fragment length polymorphism methods and of -318C/T by a PCR amplification refractory mutation system technique.

RESULTS

No statistically significant differences were found in the genotype distribution and allele frequencies among patients and controls. Haplotype analysis demonstrated that the TACG haplotype (-1722T, -1661A, -318C, +49G) frequency was significant increased in patients with colorectal cancer (P = 0.009) and gastric cancer (P = 0.006) in comparison to the control group. In contrast, the TACA haplotype frequency was significantly decreased in patients with colorectal cancer (P = 0.02) and not significantly decreased in patients with gastric cancer (P = 0.13) compared to the control group.

CONCLUSION

A positive association between CTLA-4 TACG haplotype and gastric and colorectal cancers was found in an Iranian population. A protective role for TACA haplotype is postulated.