Incidence and mortality of gastric cancer in China

Repertaxin, an inhibitor of the chemokine receptors CXCR1 and CXCR2, inhibits malignant behavior of human gastric cancer MKN45 cells in vitro and in vivo and enhances efficacy of 5-fluorouracil

Chemokine-mediated activation of G protein-coupled receptors CXCR1/2 promotes tumor growth, invasion, inflammation and metastasis. Repertaxin, a CXCR1/2 small-molecule inhibitor, has been shown to attenuate many of these tumor-associated processes. The present study aimed to investigate the effects of repertaxin alone and in combination with 5-fluorouracil (5-FU) on the malignant behavior of gastric cancer and the potential mechanisms. Gastric cancer MKN45 cells were treated in vitro with repertaxin and 5-FU, either alone or in combination. MTT and colony formation assay were performed to assess proliferation. Cell cycle progression and apoptosis was completed by flow cytometry. Migration and invasion were also assessed by Transwell and wound-healing assay. Western blot analysis and quantitative RT-PCR were performed to determine expression of signaling molecules. MKN45 cells were also grown as xenografts in nude mice. Mice were treated with repertaxin and 5-FU, and tumor volume and weight, angiogenesis, proliferation and apoptosis were monitored. Combination of repertaxin and 5-FU inhibited MKN45 cell proliferation and increased apoptosis better than either agent alone. Similarly, enhanced effect of the combination was also observed in migration and invasion assays. The improved effect of repertaxin and 5-FU was also observed in vivo, as xenograft models treated with both compounds exhibited significantly decreased tumor volume and increased apoptosis. In conclusion, repertaxin inhibited malignant behavior of human gastric cancer MKN45 cells in vitro and in vivo and enhances efficacy of 5-fluorouracil. These data provide rationale that targeting CXCR1/2 with small molecule inhibitors may enhance chemotherapeutic efficacy for the treatment of gastric cancer.

Downregulation of microRNA-193-3p inhibits tumor proliferation migration and chemoresistance in human gastric cancer by regulating PTEN gene

In this study, we investigated the functional mechanisms of microRNA-193-3p (miR-193-3p) in human gastric cancer. Quantitative RT-PCR (qRT-PCR) was used to assess whether miR-193-3p was aberrantly expressed in gastric cancer cells and clinical samples from gastric cancer patients. Gastric cancer cell line AGS and MKN-45 cells were stably transduced with lentivirus to downregulate endogenous miR-193-3p. The modulation of miR-193-3p downregulation on gastric cancer proliferation, migration, chemo-drug responses, and tumor explant were assessed by MTT, wound-healing, 5-FU chemoresistance and in vivo tumorigenicity assays, respectively. Downstream target of miR-193-3p, phosphatase and tensin homolog (PTEN) in gastric cancer, was assessed by dual-luciferase reporter assay, qRT-PCR, and western blot. PTEN was knocked down by siRNA in AGS and MKN-45 cells to assess its direct impact on miR-193-3p modulation in gastric cancer. MiR-193-3p was aberrantly upregulated in both gastric cell lines and human gastric tumors. In AGS and MKN-45 cells, miR-193-3p downregulation reduced cancer proliferation, migration and 5-FU chemoresistance in vitro, and tumorigenicity in vivo. PTEN was confirmed to be targeted by miR-193-3p in gastric cancer. PTEN inhibition in AGS and MKN-45 cells directly reversed the anti-tumor modulations of miR-193-3p downregulation on gastric cancer proliferation, migration, and 5-FU chemoresistance. We presented clear evidence showing miR-193-3p played critical role in regulating human gastric cancer through direct targeting on PTEN gene.

Health Disparity and Cancer Health Disparity in China

China is one of the largest and most populated countries in the world. It has undergone rapid economic growth in recent years. However, the development is not equitable, and the distribution of wealth significantly varies among the regions in China. Geographical and socioeconomic inequalities, together with the lack of an equitable national social support system, cause the high variance of health outcomes among the regions. Furthermore, the fast growth of the economy has evoked many environmental challenges and puts much pressure on the population. The severe environmental deterioration, especially of the atmosphere and water bodies, has affected the health of the people living in China. As a result, cancer has become a major public health issue, and an alarming increase in incidence and mortality has been reported. However, cancer incidence and mortality vary in different areas in China. Cancer and cancer treatment disparities have existed for years. This article will discuss the existing health and cancer disparities associated with the risk factors and how these disparities are managed in China.

Expression of stem cell markers nanog and PSCA in gastric cancer and its significance

The present study aimed to determine the expression of stem cell markers Nanog compared with PSCA in gastric cancer tissues and adjacent normal tissues, and to investigate the association between tumor stem cells and initiation, progression, metastasis, and prognosis of gastric cancer. One hundred chemotherapy- and radiotherapy-naive patients with pathologically confirmed gastric cancer were enrolled from the General Surgery Department and Surgical Oncology Department of the Affiliated Hospital of Inner Mongolia Medical University (Hohhot, P.R. China), between October 2011 and June 2013. Surgically resected specimens of cancer tissues and adjacent normal tissues (>5 cm from the boundary of cancerous component) were collected. The mRNA expression levels of Nanog and PSCA in those tissues was determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The correlation between the expression of stem cell markers Nanog and PSCA in gastric cancer tissues and clinicopathological factors was analyzed. The qPCR results demonstrated that the relative expression of Nanog was increased in gastric cancer tissues compared with in the adjacent tissues (P<0.05); and relative expression of PSCA was reduced in gastric cancer tissues compared with adjacent tissues (P<0.05). The expression of Nanog and PSCA in gastric cancer tissues was associated with tumor differentiation. The expression of Nanog was increased in poorly-differentiated and undifferentiated tumors compared with moderately- and well-differentiated tumors (P<0.05). The expression of PSCA was reduced in poorly differentiated and undifferentiated tumors compared with moderately- and well-differentiated tumors (P<0.05). However, the expression of Nanog and PSCA was not associated with age, gender, tumor size, TNM stage, depth of invasion, or lymph node metastasis. Therefore, Nanog and PSCA may have potential as molecular markers to reflect the differentiation status of gastric cancer.

Reduced proliferation and increased apoptosis of the SGC‑7901 gastric cancer cell line on exposure to GDC‑0449

The sonic hedgehog (Shh) pathway is known to be vital in embryonic development and cancer propagation due to its irreplaceable role in cell proliferation and differentiation. GDC‑0449, a basal cell skin cancer target drug approved by the Food and Drugs Administration, is a smoothened (Smo)-specific antagonist. Although it has been clinically verified as a valid drug for the treatment of skin and pancreatic cancer, the application of GDC‑0449 in gastric cancer requires further investigation. In the present study, high-glucose Dulbecco's modified Eagle's medium with 10% fetal bovine serum was used for routine SGC‑7901 cell line culture. A Cell Counting Kit‑8 assay was employed for determination of the reproductive rate of the cells. Flow cytometry was performed to determine the apoptosis status of the SGC‑7901 cell line through Q4 analysis. Reverse transcription-quantitative polymerase chain reaction and Western blot analyses were used as target molecule detection vehicles. As expected, GDC‑0449 reduced the expression levels of Shh‑associated molecules, including Smo and gli1, compared with the blank group. The rate of cell proliferation was markedly limited and was accompanied by an increase in the apoptotic rate following GDC‑0449 exposure. In addition, further investigations confirmed B cell lymphoma‑2 (Bcl‑2) as the downstream molecular mechanism of GDC‑0449 efficacy. Of note, representatives of the cancer stem cell (CSC) surface marker, CD44 and CD133, demonstrated a similar trend to the Smo restriction observed. By repressing the expression of Bcl‑2, GDC‑0449 inhibited the normal proliferation of SGC‑7901 cells, and accelerated the apoptotic rate of the cells. It may also alter CSC properties due to the reduction in the expression of surface markers.

Identification of biomarkers for diagnosis of gastric cancer by bioinformatics

BACKGROUND

We aimed to discover potential gene biomarkers for gastric cancer (GC) diagnosis.

MATERIALS AND METHODS

Genechips of 10 GC tissues and 10 gastric mucosa (GM, para-carcinoma tissue, normal control) tissues were generated using an exon array of Affymetrix containing 30,000 genes. The differentially expressed genes (DEGs) between GC tissues and normal control were identified by the Limma package and analyzed by hierarchical clustering analysis. Gene ontology (GO) and pathway enrichment analyses were performed for investigating the functions of DEGs. Receiver operating characteristics (ROC) analysis was performed to measure the effects of biomarker candidates for diagnosis of GC.

RESULTS

Totals of 896 up-regulated and 60 down-regulated DEGs were identified to be differentially expressed between GC samples and normal control. Hierarchical clustering analysis showed that DEGs were highly differentially expressed and most DEGs were up-regulated. The most significantly enriched GO-BP term was revealed to be mitotic cell cycle and the most significantly enriched pathway was cell cycle. The intersection analysis showed that most significant DEGs were cyclin B1 (CCNB1) and cyclin B2 (CCNB2). The sensitivities and specificities of CCNB1 and CCNB2 were both high (p<0.0001). Areas under the ROC curve for CCNB1 and CCNB2 were both greater than 0.9 (p<0.0001).

CONCLUSIONS

CCNB1 and CCNB2, which were involved in cell cycle, played significant roles in the progression and development of GC and these genes may be potential biomarkers for diagnosis and prognosis of GC.

Systemic analysis on laparoscope-assisted gastrectomy for patients with gastric cancer

BACKGROUND

Laparoscope-assisted gastrectomy in treating patients with gastric cancers developed with a background of highly invasive traditional surgery and is being increasingly performed in the Asian Pacific area. This study systemically investigated the technique and clinical results for comparison with traditional radical subtotal gastrectomy for gastric cancers.

METHODS

Clinical studies evaluating the effectiveness and side effects of laparoscope-assisted gastrectomy in treating patients with gastric cancers were identified using a predefined search strategy. Summary rates of effectiveness and side effects of laparoscope-assisted gastrectomy were calculated.

RESULTS

Thirteen clinical studies which including 1,412 patients with gastric cancer treated by laparoscope-assisted gastrectomy were considered eligible for inclusion. Systemic analysis showed that, for all patients, the pooled resection rate was 100%. Major adverse effects were anastomotic stenosis, abdominal abscess, abdominal bleeding, postoperative ileus. Treatment related death occurred in 0. 71% (10/1412).

CONCLUSION

This systemic analysis suggests that laparoscope-assisted gastrectomy in treating patients with gastric cancers is associated with good curative rate and acceptable complications.

Upregulation of a disintegrin and metalloprotease 8 is associated with progression and prognosis of patients with gastric cancer

A disintegrin and metalloprotease 8 (ADAM8) is involved in the tumorigenesis of several types of solid tumors. However, its exact role in gastric cancer (GC) remains unclear. The aim of this study was to evaluate the clinical significance of ADAM8 in GC and to explore its biological effects on gastric carcinogenesis. In this study, quantitative reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemical staining analysis revealed that ADAM8 messenger RNA expression was significantly upregulated in GC tissues compared with noncancerous tissues (P = 0.004), and that positive ADAM8 expression is much more common in tumor tissues compared with normal tissues (P < 0.001) and is correlated with T stage (P = 0.036), N stage (P = 0.048), vessel invasion (P = 0.002), and a shorter patient overall survival (P = 0.024). In vitro assay indicated that ADAM8 overexpression promoted cell growth and increased migration and invasion abilities by decreasing the p-p38/p-extracellular regulated protein kinases (p-ERK) ratio. In conclusion, ADAM8 promotes GC cell proliferation and invasion, and its expression is positively correlated with poor survival, indicating that it might be a promising target in GC therapy.

Interpreting the distinct and shared genetic characteristics between Epstein-Barr virus associated and non-associated gastric carcinoma

Gastric carcinoma is one of the major causes of cancer mortality worldwide. There is a better prognosis for patients with Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) compared with those with EBV negative gastric carcinoma (EBVnGC). It is partly due to the fact that EBV infection recruits lymphocytes infiltrating the tumor. It has been reported that this infection indeed resulted in the changes in immune response genes and thus preventing the development of tumor. It is worthwhile to do a systematic study of EBVaGC and EBVnGC based on genetic characteristics and pathways. In this study, we investigated the information of gene ontology (GO) and KEGG pathway annotations to characterize EBVaGC and EBVnGC-related genes. By applying minimum redundancy maximum relevance (mRMR) algorithm, we provided an optimal set of features for identifying the EBVaGC and EBVnGC. We also employed the shortest path algorithm to probe the novel EBVaGC- and EBVnGC-related genes based on the interaction network of genes that differently expressed in them respectively. We obtained 1039 and 1003 features to identify these two types of gastric carcinoma respectively. Based on the optimal features of classification, we predicted 1881 and 2475 novel genes as additional candidates to support clinical research respectively for these two types of gastric cancers. We compared the differences and similarities of molecular traits between EBVaGC and EBVnGC, which would facilitate the understanding of gastric cancer and its therapy and was thus clinically relevant.

Clinical Significance of MiR-137 Expression in Patients with Gastric Cancer After Radical Gastrectomy

The dysregulation of miR-137 plays vital roles in the oncogenesis and progression of various types of cancer, but its role in prognosis of gastric cancer patients remains unknown. This study was designed to investigate the expression and prognostic significance of miR-137 in gastric cancer patients after radical gastrectomy. Quantitative real-time PCR (qRT-PCR) was performed to evaluate the expression of miR-137 in human gastric cancer cell lines and tissues in patients with gastric adenocarcinoma. Results were assessed for association with clinical factors and overall survival by using Kaplan-Meier analysis. Prognostic values of miR-137 expression and clinical outcomes were evaluated by Cox regression analysis. The results exhibited that the expression level of miR-137 was decreased in human gastric cancer cell lines and tissues, and down-regulated expression of miR-137 was associated with tumor cell differentiation, N stage, and TNM stage. Decreased miR-137 expression in gastric cancer tissues was positively correlated with poor overall survival of gastric cancer patients. Further multivariate Cox regression analysis suggested that miR-137 expression was an independent prognostic indicator for gastric cancer except for TNM stage. Applying the prognostic value of miR-137 expression to TNM stage III group showed a better risk stratification for overall survival. In conclusion, the results reinforced the critical role for the down-regulated miR-137 expression in gastric cancer and suggested that miR-137 expression could be a prognostic indicator for this disease. In addition, these patients with TNM stage III gastric cancer and low miR-137 expression might need more aggressive postoperative treatment and closer follow-up.

Relationship between CIP2A expression, and prognosis and MDR-related proteins in patients with advanced gastric cancer

CIP2A is highly expressed in a variety of malignancies. We determined the expression and clinical significance of CIP2A in patients with advanced gastric cancer. CIP2A protein was expressed in 25 of 37 cancer tissue specimens. There was no correlation between CIP2A and PGP, GST-π, Topo-II, and LRP expression. Survival analysis showed significant differences between the survival rate of the CIP2A protein-positive and -negative groups (χ(2)=4.509, P=0.034), but the degree of positive expression was unrelated to survival time (χ(2)=4.639, P=0.098). CIP2A expression may have no prospective value for optimizing chemotherapy regimens, but it can be an indicator for patient prognosis.

TCEA3 Attenuates Gastric Cancer Growth by Apoptosis Induction

Background

The aim of this study was to investigate and interpret the expression level and potential function of TCEA3 in gastric cancer.

Material/Methods

qRT-PCR was used to determine the expression level of TCEA3 in gastric cancer tissues. Pearson χ² test was performed to clarify the correlation between TCEA3 expression and patients’ clinicopathologic characteristics. Biological function of TCEA3 was tested by proliferation assay and colony formation assay. Flow cytometry was used to study the potential function of TCEA3 in apoptosis induction.

Results

TCEA3 expression was significantly downregulated in gastric cancer tissues compared with paired normal tissues. Poor prognoses were observed in the low TCEA3 expression group of patients in contrast to the high TCEA3 expression group. Functionally, upregulation of TCEA3 inhibited gastric cancer cell proliferation and colony formation. We also found that TCEA3 may attenuate cell growth through apoptosis induction.

Conclusions

Our findings suggest that TCEA3 attenuates the proliferation and induces apoptosis of gastric cancer cells.

Decreased expression and frequent promoter hypermethylation of RASSF2 and RASSF6 correlate with malignant progression and poor prognosis of gastric cardia adenocarcinoma

The RAS-association domain family (RASSF) consists of 10 members, and several members act as tumor suppressor genes and epigenetically inactivated in different tumor types. The present study investigated the role and methylation status of RASSF2, RASSF3, RASSF4, and RASSF6 in the pathogenesis and prognosis of GCA. Quantitative real-time RT-PCR, Western blot, and immunohistochemistry (IHC) methods were used respectively to detect the expression of RASSF2, RASSF3, RASSF4, and RASSF6 in 135 GCA cases and BS-MSP method was used to clarify the methylation status of these four genes. Decreased mRNA and protein expression of RASSF2, RASSF3, RASSF4, and RASSF6 were detected in GCA tumor tissues. Aberrant CpG island methylation of RASSF2, RASSF4, and RASSF6 were detected in GCA tumor tissues and were inversely correlated with the expression levels of these genes. Both of RASSF2 and RASSF6 expression and methylation were associated with TNM stage, depth of invasion, LN metastasis, distant metastasis or recurrence, and UGIC family history. GCA patients with simultaneous negative protein expression of RASSF2 and RASSF6 or with simultaneous methylation of both genes demonstrated poor patient survival. These results suggest that down-regulation of RASSF2, RASSF3, RASSF4, and RASSF6 is a tumor-specific phenomenon and the inactivation of RASSF2 and RASSF6 may be associated with tumor progression. Inactivation of RASSF2, RASSF4, and RASSF6 through CpG island methylation may play important roles in GCA carcinogenesis. A combination of RASSF2 and RASSF6 expression or hypermethylation may serve as useful prognostic biomarker for GCA. © 2015 Wiley Periodicals, Inc.

Guanine nucleotide binding protein-like 3 is a potential prognosis indicator of gastric cancer

Guanine nucleotide binding protein-like 3 (GNL3) is a GIP-binding nuclear protein that has been reported to be involved in various biological processes, including cell proliferation, cellular senescence and tumorigenesis. This study aimed to investigate the expression level of GNL3 in gastric cancer and to evaluate the relationship between its expression and clinical variables and overall survival of gastric cancer patients. The expression level of GNL3 was examined in 89 human gastric cancer samples using immunohistochemistry (IHC) staining. GNL3 in gastric cancer tissues was significantly upregulated compared with paracancerous tissues. GNL3 expression in adjacent non-cancerous tissues was associated with sex and tumor size. Survival analyses showed that GNL3 expression in both gastric cancer and adjacent non-cancerous tissues were not related to overall survival. However, in the subgroup of patients with larger tumor size (≥ 6 cm), a close association was found between GNL3 expression in gastric cancer tissues and overall survival. GNL3-positive patients had a shorter survival than GNL3-negative patients. Our study suggests that GNL3 might play an important role in the progression of gastric cancer and serve as a biomarker for poor prognosis in gastric cancer patients.

Curcumin Suppresses MAPK Pathways to Reverse Tobacco Smoke-induced Gastric Epithelial-Mesenchymal Transition in Mice

Tobacco smoke (TS) has been shown to cause gastric cancer. Epithelial-mesenchymal transition (EMT) is a crucial pathophysiological process in cancer development. Mitogen-activated protein kinase (MAPK) pathways play central roles in tumorigenesis including EMT process. Curcumin is a promising chemopreventive agent for several types of cancers. In the present study, we investigated the effects of TS on MAPK pathway activation and EMT alterations in the stomach of mice, and the preventive effect of curcumin was further examined. Results showed that exposure of mice to TS for 12 weeks resulted in activation of extracellular regulated protein kinases 1 and 2 (ERK1/2), the Jun N-terminal kinase (JNK), p38, and ERK5 MAPK pathways as well as activator protein 1 (AP-1) proteins in stomach. TS reduced the mRNA and protein expression levels of the epithelial markers E-cadherin and ZO-1, while the mRNA and protein expression levels of the mesenchymal markers vimentin and N-cadherin were increased. Treatment of curcumin effectively abrogated TS-triggered gastric activation of ERK1/2 and JNK MAPK pathways, AP-1 proteins, and EMT alterations. These results suggest for the first time the protective effects of curcumin in long-term TS exposure-induced gastric MAPK activation and EMT, thus providing new insights into the pathogenesis and chemoprevention of TS-associated gastric cancer.

DNA methyltransferase 3A promotes cell proliferation by silencing CDK inhibitor p18INK4C in gastric carcinogenesis

Little is known about the roles of DNA methyltransferase 3A (DNMT3A) in gastric carcinogenesis. Here, we reported that the exogenous expression of DNMT3A promoted gastric cancer (GC) cell proliferation by accelerating the G1/S transition. Subsequently, p18^INK4C was identified as a downstream target of DNMT3A. The elevated expression of DNMT3A suppressed p18^INK4C at least at the transcriptional level. Depletion of p18^INK4C expression in GC cells induced cell cycle progression, whereas its re-expression alleviated the effect of DNMT3A overexpression on G1/S transition. Furthermore, we found that DNMT3A modulated p18^INK4C by directly binding to and silencing the p18^INK4C gene via promoter hypermethylation. In clinical GC tissue specimens analyzed, the level of methylation of p18^INK4C detected in tumor tissues was significantly higher than that in paired non-tumor tissues. Moreover, elevated level of DNMT3A expression was associated with the differentiation of GC tissues and was negatively correlated with the p18^INK4C expression level. Taken together, our results found that DNMT3A contributes to the dysregulation of the cell cycle by repressing p18^INK4C in a DNA methylation-dependent manner, suggesting that DNMT3A-p18^INK4C axis involved in GC. These findings provide new insights into gastric carcinogenesis and a potential therapeutic target for GC that may be further investigated in the future.

MiR-338-3p inhibits the proliferation and migration of gastric cancer cells by targeting ADAM17

BACKGROUND

MicroRNAs (miRNA) have been documented playing a critical role in cancer progression. Although miR-338-3p has been implicated in several cancers, its role in gastric cancer is still unknown. The aim of our study was to investigate the role of miR-338-3p in gastric cancer progression.

METHODS

Expression levels of miR-338-3p in gastric cancer cell lines and tissues were determined by quantitative real-time PCR (qRT-PCR). The effect of miR-338-3p on proliferation was evaluated by MTT assay, cell migration and invasion were evaluated by transwell migration and invasion assays. Furthermore, luciferase reporter assay was conducted to confirm the target gene of miR-338-3p, and the results were validated in gastric cancer cells.

RESULTS

In the present study, we found that miR-338-3p was down-regulated in both gastric cancer cell lines and tissues. Enforced expression of miR-338-3p inhibited proliferation, migration and invasion of gastric cancer cells in vitro. Moreover, we identified A disintegrin and metalloproteinase 17 (ADAM17) gene as potential target of miR-338-3p. Importantly, ADAM17 rescued the miR-338-3p mediated inhibition of cell proliferation, migration and invasion.

CONCLUSIONS

Our study suggested that miR-338-3p is significantly decreased in gastric cancer, and inhibits cell proliferation, migration and invasion partially via the downregulation of ADAM17. Thus, miR-338-3p may represent a potential therapeutic target for gastric cancer intervention.

Two novel variants on 13q22.1 are associated with risk of esophageal squamous cell carcinoma

BACKGROUND

Chromosome 13q22.1 has previously been identified to be a susceptibility locus for pancreatic cancer in Chinese and European ancestry populations. This pleiotropy study aimed to identify novel variants in this region associated with susceptibility to different types of human cancer.

METHOD

To fine-map the 13q22.1 region, imputation analyses were conducted on the basis of the GWAS data of 2,031 esophageal squamous cell cancer (ESCC) cases and 2,044 controls and 5,930 SNPs (625 directly genotyped and 5,305 well imputed). Promising associations were then examined in ESCC (4,146 cases and 4,135 controls), gastric cardia cancer (1,894 cases and 1,912 controls), noncardia gastric cancer (1,007 cases and 2,243 controls), and colorectal cancer (1,111 cases and 1,138 controls). Fine mapping and biochemical analyses were further performed to elucidate the potential function of novel variants.

RESULTS

Two novel variants, rs1924966 and rs115797771, were associated with ESCC risk (P = 1.37 × 10(-10) and P = 2.32 × 10(-10), respectively) and were also associated with risk of gastric cardia cancer (P = 0.0003 and P = 0.0018, respectively) but not gastric cancer and colorectal cancer. Fine-mapping revealed another SNP, rs58090485, in strong linkage disequilibrium with rs115797771 (r(2) = 0.94). Functional analysis showed that this SNP disturbs a transcriptional repressor binding to the promoter region of KLF5, which might result in high constitutional expression of KLF5.

CONCLUSIONS

These results demonstrate that variants mapped on 13q22.1 are associated with the risk of different types of cancer.

IMPACT

13q22.1 might serve as a biomarker for the identification of individuals at risk for ESCC and gastric cardia cancer.

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.

Long non-coding RNA MEG3 functions as a competing endogenous RNA to regulate gastric cancer progression

Background

Long noncoding RNAs (lncRNAs) have recently emerged as important regulators in governing fundamental biological processes, and many of which are likely to have functional roles in tumorigenesis. Maternally expressed gene 3 (MEG3) gene encodes a lncRNA whose expression is lost in an expanding list of primary human tumors and tumor cell lines, however its biological role and regulatory mechanism in gastric cancer (GC) development and progression are poorly defined.

Methods

Quantitative RT-PCR analysis was used to determine whether aberrant MEG3 expression was associated with GC patients pTNM stage and pM state. Furthermore, the effect of ectopic expression of MEG3 on cell proliferation, migration, invasion and cell apoptosis was assessed by using CCK-8, wound healing, transwell invasion assays and flow cytometric analysis, respectively, in GC cell lines HGC-27 and MGC-803. Moreover, the competing endogenous RNA (ceRNA) activity of MEG3 on miR-181a was investigated via luciferase reporter assay and immunoblot analysis.

Results

MEG3 is decreased in GC patients and cell lines, and its expression was associated with metastatic GC. Furthermore, ectopic expression of MEG3 in HGC-27 and MGC-803 cells inhibited cell proliferation, migration, invasion, and promoted cell apoptosis, which might be due to MEG3 sequestering oncogenic miR-181 s in GC cells. Furthermore, MEG3 could up-regulated Bcl-2 via its competing endogenous RNA (ceRNA) activity on miR-181a.

Conclusions

These findings suggest that lncRNA MEG3, a ceRNA of miR-181 s, could regulate gastric carcinogenesis and may serve as a potential target for antineoplastic therapies.

Long non-coding RNA MEG3 functions as a competing endogenous RNA to regulate gastric cancer progression

BACKGROUND

Long noncoding RNAs (lncRNAs) have recently emerged as important regulators in governing fundamental biological processes, and many of which are likely to have functional roles in tumorigenesis. Maternally expressed gene 3 (MEG3) gene encodes a lncRNA whose expression is lost in an expanding list of primary human tumors and tumor cell lines, however its biological role and regulatory mechanism in gastric cancer (GC) development and progression are poorly defined.

METHODS

Quantitative RT-PCR analysis was used to determine whether aberrant MEG3 expression was associated with GC patients pTNM stage and pM state. Furthermore, the effect of ectopic expression of MEG3 on cell proliferation, migration, invasion and cell apoptosis was assessed by using CCK-8, wound healing, transwell invasion assays and flow cytometric analysis, respectively, in GC cell lines HGC-27 and MGC-803. Moreover, the competing endogenous RNA (ceRNA) activity of MEG3 on miR-181a was investigated via luciferase reporter assay and immunoblot analysis.

RESULTS

MEG3 is decreased in GC patients and cell lines, and its expression was associated with metastatic GC. Furthermore, ectopic expression of MEG3 in HGC-27 and MGC-803 cells inhibited cell proliferation, migration, invasion, and promoted cell apoptosis, which might be due to MEG3 sequestering oncogenic miR-181 s in GC cells. Furthermore, MEG3 could up-regulated Bcl-2 via its competing endogenous RNA (ceRNA) activity on miR-181a.

CONCLUSIONS

These findings suggest that lncRNA MEG3, a ceRNA of miR-181 s, could regulate gastric carcinogenesis and may serve as a potential target for antineoplastic therapies.

Genetic polymorphism of miR-146a is associated with gastric cancer risk: a meta-analysis

Several studies have investigated the associations between miR-146a rs2910164 and gastric cancer (GC) risk, but results have been inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. PubMed and China National Knowledge Infrastructure searches were carried out for relevant studies published before July 2014. Meta-analysis was performed with the stata, version 11.0. A total of seven case-control studies, including 3283 cases and 4535 controls, were selected. A significant association was found between rs2910164 and GC risk under all genetic models (CC vs. GG, OR = 0.76, 95% CI = 0.66-0.87; CC vs. GC+GG, OR = 0.84, 95% CI = 0.71-0.99; CC+GC vs. GG, OR = 0.82, 95% CI = 0.73-0.91) for the total data. In the subgroup analysis by ethnicity, statistically significant association was found in Asian. This meta-analysis suggested that the miR-146a rs2910164 was a risk factor for developing GC.

Association of miR-193b down-regulation and miR-196a up-regulation with clinicopathological features and prognosis in gastric cancer

Dysregulated expression of microRNAs (miRNAs) has been shown to be closely associated with tumor development, progression, and carcinogenesis. However, their clinical implications for gastric cancer remain elusive. To investigate the hypothesis that genome-wide alternations of miRNAs differentiate gastric cancer tissues from those matched adjacent non-tumor tissues (ANTTs), miRNA arrays were employed to examine miRNA expression profiles for the 5-pair discovery stage, and the quantitative real-time polymerase chain reaction (qRT- PCR) was applied to validate candidate miRNAs for 48-pair validation stage. Furthermore, the relationship between altered miRNA and clinicopathological features and prognosis of gastric cancer was explored. Among a total of 1,146 miRNAs analyzed, 16 miRNAs were found to be significantly different expressed in tissues from gastric cancer compared to ANTTs (p<0.05). qRT-PCR further confirmed the variation in expression of miR-193b and miR-196a in the validation stage. Down-expression of miR-193b was significantly correlated with Lauren type, differentiation, UICC stage, invasion, and metastasis of gastric cancer (p<0.05), while over-expression of miR-196a was significantly associated with poor differentiation (p=0.022). Moreover, binary logistic regression analysis demonstrated that the UICC stage was a significant risk factor for down-expression of miR-193b (adjusted OR=8.69; 95%CI=1.06-56.91; p=0.043). Additionally, Kaplan-Meier survival curves indicated that patients with a high fold-change of down-regulated miR-193b had a significantly shorter survival time (n=19; median survival=29 months) compared to patients with a low fold-change of down-regulated miR-193b (n=29; median survival=54 months) (p=0.001). Overall survival time of patients with a low fold-change of up-regulated miR- 196a (n=27; median survival=52 months) was significantly longer than that of patients with a high fold-change of up-regulated miR-196a (n=21; median survival=46 months) (p=0.003). Hence, miR-193b and miR-196a may be applied as novel and promising prognostic markers in gastric cancer.

Association of risk of gastric cancer and consumption of tobacco, alcohol and tea in the Chinese population

This study aimed at summarizing epidemiological research findings on associations between tobacco, alcohol and tea consumption and risk of gastric cancer (GC) in the Chinese population. The review searched PubMed, Embase, China National Knowledge Infrastructure (CNKI) and China Biology Medicine (CBM) databases and reference lists of review papers for all studies published in English or Chinese languages. Information extracted, via two independent researchers, from retrieved articles included first author, year of publication, study design, sample size, source of controls and adjusted odds ratio (OR) or relative risk (RR) with the corresponding 95% confidence intervals (CIs) for each category. Statistical analyses used software STATA version 12.0. The systematic search found 89 articles containing 25,821 GC cases and 135,298 non-cases. The overall random effects in terms of pooled OR and 95%CI for tobacco, alcohol and tea consumption were 1.62 (95%CI: 1.50-1.74), 1.57 (95%CI: 1.41-1.76) and 0.67 (95%CI: 0.59-0.76) respectively; while the heterogeneity among included studies ranged from 80.1% to 87.5%. The majority of subgroup analyses revealed consistent results with the overall analyses. All three behavioral factors showed statistically significant dose-dependent effects on GC (P<0.05). The study revealed that tobacco smoking and alcohol drinking were associated with over 1/2 added risk of GC, while tea drinking conferred about 1/3 lower risk of GC in the Chinese population. However, these results should be interpreted with caution given the fact that most of the included studies were based on a retrospective design and heterogeneity among studies was relatively high.

Elevated Rictor expression is associated with tumor progression and poor prognosis in patients with gastric cancer

The rapamycin insensitive companion of mTOR (Rictor) is an essential subunit of mTOR complex 2 (mTORC2), maintains the integrity of the complex and functions as regulator of Akt full activation. Rictor has been implicated to be involved in growth and progression of malignancies, however, little is known about its expression and prognostic role in gastric cancer in particular. Therefore, we investigated the relationship of Rictor expression with clinical outcomes, together with pAktSer473 and pS6, two downstream substrates of mTORC2 and mTORC1, in 396 gastric cancer tissue samples via immunohistochemistry. The results showed that 74.0% and 55.8% of tumors were Rictor and pAktSer473 positive staining, respectively, which correlated well with each other. Patients with positive expressions had poorer overall survival and relapse-free survival compared with those negative staining. Both Rictor and pAktSer473 expression were associated with lymph node metastasis, TNM stage, and WHO grading. Rictor was also correlated with tumor size, depth of invasion, and tumor thrombus, while pAktSer473 was also correlated with distant metastasis. In spite of 67.4% expression rate was presented in gastric cancer tissues, no significant association was observed between pS6Ser235/236, representing mTORC1 activity, and clinicopathological features or prognosis. These results suggest that mTORC2/Rictor/pAkt may play a more important role than mTORC1/pS6 in tumor progression, which could act as a prognostic biomarker or potential therapeutic target in gastric cancer.

An association study of histological types of gastric carcinoma with Helicobacter pylori infection

The aim of this study was to study the relation between histopathological classification of gastric carcinoma and Helicobacter pylori (H. pylori) infection. 200 patients with confirmed gastric carcinoma between January 2010 and January 2012 from our hospital were included. All these patients went through endoscopy and histological examinations for gastric carcinoma and immunological test for H. pylori infection. Patients were grouped according to the histological classification, and the infection rates of H. pylori in different groups were compared. Types of gastric cancer that was closely related to H. pylori infection were identified. Infection rate in patients with the intestinal type of gastric cancer was significantly higher compared to those with the diffuse type. For tubular type of carcinoma, the well to medium-differentiated group had a significantly higher infection rate than the poorly differentiated group. Helicobacter pylori infection and histological types were relevant. The effect of H. pylori infection on the intestinal type was more significant than that on the diffuse type. The infection rate of well-differentiated group was higher than that of the poorly differentiated group, which suggested an association between H. pylori infection and the degree of differentiation of tubular cancerous tissue.

Randomized controlled trial comparing gastric cancer screening by gastrointestinal X-ray with serology for Helicobacter pylori and pepsinogens followed by gastrointestinal endoscopy

BACKGROUND

Based on the results of several case-control and cohort studies gastrointestinal X-ray (GI X-ray) has been recommended for use in the nationwide screening program for gastric cancer.. Although this was the only effective screening program when almost all of the Japanese population were Helicobacter pylori (H. pylori) positive, there has been concern whether an alternative effective screening system should be established for the future H. pylori-negative generation. We therefore conducted the first randomized controlled trial (RCT) comparing GI X-ray and gastrointestinal endoscopy (GIE) scheduled according to results of serological testing (ST); this was done to determine the potential for an alternative screening method.

METHODS

Subjects who fulfilled the inclusion criteria were residents between the ages of 30 and 74 and who were able to receive gastric cancer screening in the Yurihonjo area. Participants were assigned to the GI X-ray group or the GIE-ST group by computer randomization. Subjects in each group were further subdivided into 4 categories according to their different risks for gastric cancer. The feasibility of stratified randomization was serologically assessed and detection rates of gastric cancer at entry by the different screening methods were also compared.

RESULTS

Of the 2,962 subjects invited, 1,206 individuals (41 percent) were included in the first stage of this stratified RCT, and 604 and 602 individuals were assigned to the GI X-ray group and the GIE-ST group, respectively. There were no statistically significant differences in sex, age, height, body weight, smoking, alcohol intake and family history of cancer between the 2 groups. During ST the GI X-ray group showed a distribution that was not statistically different from that of the GIE-ST group. Although 3 cases of gastric cancer were detected in the GIE-ST group, there was no statistically significant difference between the 2 groups. One complication found was barium aspiration during the examination in the X-ray group.

CONCLUSION

We confirmed that baseline demographic features of the 2 groups were well balanced. We are now organizing the first RCT to compare the existing screening method and the alternative method (Clinical trial registration number: UMIN000005962).

The MicroRNA-217 Functions as a Potential Tumor Suppressor in Gastric Cancer by Targeting GPC5

Gastric cancer (GC) is one of the most common malignancies worldwide. Emerging evidence has shown that aberrant expression of microRNAs (miRNAs) plays important roles in cancer progression. However, little is known about the potential role of miR-217 in GC. In this study, we investigated the role of miR-217 on GC cell proliferation and invasion. The expression of miR-217 was down-regulated in GC cells and human GC tissues. Enforced expression of miR-217 inhibited GC cells proliferation and invasion. Moreover, Glypican-5 (GPC5), a new ocncogene, was identified as the potential target of miR-217. In addition, overexpression of miR-217 impaired GPC5-induced promotion of proliferation and invasion in GC cells. In conclusion, these findings revealed that miR-217 functioned as a tumor suppressor and inhibited the proliferation and invasion of GC cells by targeting GPC5, which might consequently serve as a therapeutic target for GC patients.

Endoscopic Raman Spectroscopy for Molecular Fingerprinting of Gastric Cancer: Principle to Implementation

Currently, positive endoscopic biopsy is the standard criterion for gastric cancer diagnosis but is invasive, often inconsistent, and delayed although early detection and early treatment is the most important policy. Raman spectroscopy is a spectroscopic technique based on inelastic scattering of monochromatic light. Raman spectrum represents molecular composition of the interrogated volume providing a direct molecular fingerprint. Several investigations revealed that Raman spectroscopy can differentiate normal, dysplastic, and adenocarcinoma gastric tissue with high sensitivity and specificity. Moreover, this technique can indentify malignant ulcer and showed the capability to analyze the carcinogenesis process. Automated on-line Raman spectral diagnostic system raised possibility to use Raman spectroscopy in clinical field. Raman spectroscopy can be applied in many fields such as guiding a target biopsy, optical biopsy in bleeding prone situation, and delineating the margin of the lesion. With wide field technology, Raman spectroscopy is expected to have specific role in our future clinical field.

The Influence of PSCA Gene Variation on Its Expression and Gastric Adenocarcinoma Susceptibility in the Northwest Chinese Population

Gastric adenocarcinoma (GAC) imposes a considerable health burden around the world. Gene variation in prostate stem cell antigen gene (PSCA) has been identified to be associated with GAC risk, while the results showed regional variation. To explore the influence of PSCA gene variation on its expression and GAC risk in the Northwest Chinese population, four single nucleotide polymorphisms (SNPs) of PSCA were genotyped in 476 GAC cases and 481 controls using MassARRAY system. Two SNPs of rs2294008 (C>T) and rs2976392 (G>A) were identified to be associated with GAC risk. rs2294008, rs2976392 and rs10216533 made up two statistically significant haplotypes (Hap-CGG and Hap-TAG). Additionally, PSCA expression was analyzed by quantitative real time PCR, immunohistochemistry and tissue microarray. The results showed that PSCA expression was decreased in GAC tissues compared with adjacent normal tissues. For normal tissues, PSCA expression was higher with Hap-TA than that with Hap-CG. For GAC tissues, the differentiation degree of Hap-TA was higher than that of Hap-CG. The expression distribution of PSCA in multiple human organs showed disparity. These results suggest that PSCA gene variation has a potential effect on its expression and GAC risk in the Northwest Chinese population.

Effect of the number of lymph nodes harvested on the long-term survival of gastric cancer patients according to tumor stage and location: a 12-year study of 1,637 cases

BACKGROUND

The effect of the number of lymph nodes harvested on the long-term survival of gastric cancer according to Tumor, Node, and Metastasis (TNM) stage and tumor location remains unclear.

METHODS

Patients who underwent gastrectomy for gastric cancer (1998 to 2009) were evaluated retrospectively (1,637 patients). The patients' clinicopathological variables, overall survival (OS), and progression-free survival (PFS) were recorded. The effect of the number of lymph nodes harvested on survival was analyzed according to TNM stage and tumor location.

RESULTS

Harvest of greater than 30 lymph nodes was associated with significantly better OS and PFS than less than or equal to 14 lymph nodes, but no significant difference was observed between less than or equal to 14 and 15 to 29 lymph nodes harvested. The number of lymph nodes harvested was significantly associated with the OS or/and PFS of late stage cancer (N+, T3 to T4, and stage III to IV), harvest of greater than 30 lymph nodes brought significantly better survival compared with the other 2 groups. A higher number of harvested lymph nodes was associated with significantly better PFS for gastric cancer of the body of stomach, but not for proximal, distal, and whole stomach cancer. When the tumor was located in the body of the stomach, the PFS was better with 15 to 29 lymph nodes than less than 14 lymph nodes; however, the OS and PFS were not significantly different between greater than 30 lymph nodes and 15 to 29 lymph nodes. TNM stage and number of lymph nodes harvested were the independent risk factors affecting the survival.

CONCLUSION

Tailored lymphadenectomy according to TNM stage and tumor location might be considered for gastric cancer patients.

Downregulation of long noncoding RNA ZMAT1 transcript variant 2 predicts a poor prognosis in patients with gastric cancer

Gastric cancer is the second most common cause of cancer-related death partially because of its aggressive metastasis and the fact that it is often diagnosed at an advanced stage. Recent studies have shown that long noncoding RNAs (lncRNAs) play critical roles in multiple biological processes including oncogenesis. In the present study, we found for the first time that the lncRNA ZMAT1 transcript variant 2 is downregulated in gastric cancer tissues compared with adjacent normal tissues (P<0.001). The expression of ZMAT1 transcript variant 2 was inversely correlated with lymph node metastasis (P<0.05), depth of tumor invasion and tumor node metastasis stage (P<0.05). Univariate and multivariate analyses showed that ZMAT1 transcript variant 2 expression was an independent predictor for overall survival (P<0.05). Our study suggests that ZMAT1 transcript variant 2 is a potential diagnostic factor in patients with gastric cancer.

Preoperative psychological distress, coping and quality of life in Chinese patients with newly diagnosed gastric cancer

AIMS AND OBJECTIVES

The purpose of this study was to investigate the prevalence of preoperative psychological distress and its relationship with coping style and quality of life in Chinese patients with newly diagnosed gastric cancer.

BACKGROUND

Being newly diagnosed with cancer can be a source of psychological distress. Understanding the preoperative psychological distress may contribute to the development of appropriate interventions.

DESIGN

This is a descriptive correlational survey study.

METHODS

The study was conducted in two teaching hospitals in Anhui province, China. A total of 165 patients with gastric cancer completed a battery of self-report questionnaires including the Distress Thermometer, the revised Chinese version of the Quality of Life Questionnaire-Stomach 22 and the Cancer Coping Modes Questionnaire.

RESULTS

The prevalence of clinically significant preoperative psychological distress was 76·97% in this group. Statistically significant correlations were identified between the distress score and stomach pain, eating restrictions and anxiety subscale. Positive associations were found between the distress scores and four subdimensions of coping (avoidance and suppression, resignation, fantasy and catharsis), whereas a negative association was found between the distress scores and one subdimension of coping (Confrontation). There were also significant differences in the quality of life and coping style of patients who had different psychological distress statuses.

CONCLUSION

These findings indicate a relatively high prevalence of preoperative psychological distress among Chinese patients with gastric cancer. Patients with clinically psychological distress were more likely to have poor quality of life and to demonstrate negative coping styles.

RELEVANCE TO CLINICAL PRACTICE

Nursing professionals need to carefully assess the psychological status of patients with gastric cancer. Tailored interventions can be administered to help these patients appropriately cope with the disease and to enhance their quality of life.

Effects of Two Common Polymorphisms rs2910164 in miR-146a and rs11614913 in miR-196a2 on Gastric Cancer Susceptibility

Background. Single nucleotide polymorphisms (SNPs) in genes encoding microRNAs may play important role in the development of gastric cancer. It has been reported that common SNPs rs2910164 in miR-146a and rs11614913 in miR-196a2 are associated with susceptibility to gastric cancer. The published results remain inconclusive or even controversial. A meta-analysis was conducted to quantitatively assess potential association between the two common SNPs and gastric cancer risk. Methods. A comprehensive literature search was performed in multiple internet-based electronic databases. Data from 12 eligible studies were extracted to estimate pooled odds ratios (ORs) and 95% confidence intervals (95% CI). Results. C allele of rs2910164 is associated with reduced gastric cancer risk in heterozygote model and dominant model whereas rs11614913 indicates no significant association. Subgroup analysis demonstrates that C allele of rs2910164 and rs11614913 may decrease susceptibility to diffuse type gastric cancer in dominant model and recessive model, respectively, while rs11614913 increased intestinal type gastric cancer in dominant model. Conclusion. SNPs rs2910164 and rs11614913 might have effect on gastric cancer risk in certain genetic models and specific types of cancer. Further well-designed studies should be considered to validate the potential effect.

Effect of Helicobacter pylori Infection on the Composition of Gastric Microbiota in the Development of Gastric Cancer

BACKGROUND

Gastric cancer is one of the most common cancer types worldwide. In China, gastric cancer has become one of the major threats for public health, ranking second on incidence and third on cause of cancer death. Despite the common risk factors that promote the development of gastric cancer, the huge quantity of microorganism colonies within the gastrointestinal tract, particularly Helicobacter pylori infection, demonstrates a correlation with chronic inflammation and gastric carcinogenesis, as epidemiological studies have determined that H. pylori infection confers approximately 75% of the attributable risk for gastric cancer.

SUMMARY

The current article draws an overview on the correlation between the microbiota, inflammation and gastric tumorigenesis. H. pylori infection has been identified as the main risk factor as it triggers epithelial barrier disruption, survival signaling as well as genetic/epigenetic modulation. Apart from H. pylori, the existence of a diverse and complex composition of microbiota in the stomach has been identified, which supports a role of microbiota in the development of gastric cancer. Moreover, metagenomics studies focused on the composition and function of the microbiota have associated microbiota with gastric metabolic diseases and even tumorigenesis. Apart from the gastric microbiota, inflammation is another identified contributor to cancer development as well.

KEY MESSAGE

Though H. pylori infection and the non-H. pylori microbiota play a role in gastric cancer, the properties of gastric microbiota and mechanisms by which they participate in the genesis of gastric cancer are still not clearly depicted. Moreover, it remains to be understood how the presence of microbiota along with H. pylori infection affects the progress from gastric disease to cancer.

PRACTICAL IMPLICATIONS

This article summarized a clue of the current studies on microbiota, H. pylori infection and the progression from gastric disease to cancer.

Inflammatory serum proteins are severely altered in metastatic gastric adenocarcinoma patients from the Chinese population

BACKGROUND

Inflammation is one of the major hallmarks of cancer. This study was designed to profile a panel of inflammatory mediators in gastric adenocarcinoma (GA) and to identify their potential differences separately in metastatic and non-metastatic patient subgroups.

METHODS

Serum samples from 216 GA patients and 333 healthy controls from China were analyzed for six proteins using the Luminex multiplex assay.

RESULTS

The serum levels for all the six proteins were significantly elevated in metastatic GA compared to non-metastatic GA. Two acute phase proteins (SAA and CRP) and a CXC chemokine (GRO) were significantly elevated in metastatic GA (p <0.01) but smaller changes were observed in non-metastatic GA compared to healthy controls. OPN is moderately increased in non-metastatic GA (2.05-fold) and more severely elevated in metastatic GA (3.34-fold). Surprisingly, soluble VCAM1 and AGP were significantly lower in both non-metastatic and metastatic GA patients compared to controls. Several individual proteins were shown to possess moderate diagnostic value for non-metastatic GA (AUC = 0.786, 0.833, 0.823 for OPN, sVCAM1 and AGP, respectively) and metastatic GA (AUC = 0.931, 0.720, 0.834 and 0.737 for OPN, sVCAM1, SAA and CRP, respectively). However, protein combinations further improve the diagnostic potential for both non-metastatic GA (best AUC = 0.946) and metastatic GA (best AUC = 0.963). The protein combination with best AUC value for both comparisons is OPN+sVCAM1+AGP+SAA.

CONCLUSIONS

These results suggest that several serum proteins are directly related to the severity of gastric cancer. Overall, stronger associations are observed with metastatic than non-metastatic GA as the protein changes are greater with the metastatic status. A combination of these serum proteins may serve as non-invasive markers to assess the severity status and stage of gastric cancer.

Characteristics of gastric cancer in Asia

Gastric cancer (GC) is the fourth most common cancer in the world with more than 70% of cases occur in the developing world. More than 50% of cases occur in Eastern Asia. GC is the second leading cause of cancer death in both sexes worldwide. In Asia, GC is the third most common cancer after breast and lung and is the second most common cause of cancer death after lung cancer. Although the incidence and mortality rates are slowly declining in many countries of Asia, GC still remains a significant public health problem. The incidence and mortality varies according to the geographic area in Asia. These variations are closely related to the prevalence of GC risk factors; especially Helicobacter pylori (H. pylori) and its molecular virulent characteristics. The gradual and consistent improvements in socioeconomic conditions in Asia have lowered the H. pylori seroprevalence rates leading to a reduction in the GC incidence. However, GC remains a significant public health and an economic burden in Asia. There has been no recent systemic review of GC incidence, mortality, and H. pylori molecular epidemiology in Asia. The aim of this report is to review the GC incidence, mortality, and linkage to H. pylori in Asia.

Clinicopathological features of gastric carcinoma in Ibadan, Nigeria, 2000-2011

Aim:

The most recent study on the clinicopathological features of gastric carcinoma from the University College Hospital (UCH), Ibadan, was done in 2000. The aim of this study is to update the knowledge on the clinicopathological features of gastric carcinoma diagnosed in the Pathology Department of the UCH Ibadan between 2000 and 2011.

Materials and Methods:

This was a 12-year retrospective review of clinical and demographic data and the histopathological features of gastric cancers diagnosed at the Pathology Department of the UCH. The chi square test, Fisher's exact test, and the t-independent test were used as applicable in the statistical analyses.

Results:

A total of 117 cases of gastric carcinoma were histologically diagnosed at the Pathology Department of UCH, Ibadan in this period giving a relative ratio frequency of 1.38% for all cancers. It represented 18.4% of all gastrointestinal tract malignancies diagnosed in the same period. There was a male preponderance with male:female ratio of 1.72:1; the middle-aged and elderly made up about 76.1% of cases. The disease was clinically and histologically advanced in 92.8% of cases. Gastric tumours were predominantly antral/ pyloric in 80% of cases and exophytic in 62.3% of cases. The intestinal histotype constituted 47.0% cases although a rise in the diffuse histological type was observed.

Conclusion:

There is a decline in the relative ratio frequency of gastric carcinoma in Ibadan; and a fall in the rate of the intestinal type of gastric carcinoma relative to the diffuse type when compared to previous studies from our centre.

Cisplatin-mediated c-myc overexpression and cytochrome c (cyt c) release result in the up-regulation of the death receptors DR4 and DR5 and the activation of caspase 3 and caspase 9, likely responsible for the TRAIL-sensitizing effect of cisplatin

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) reverses multidrug resistance (MDR) and induces apoptosis in MDR gastric carcinoma cells. In our previous study, cisplatin proved to be a sensitizing agent for TRAIL. To study the synergistic effects of cisplatin and TRAIL, we investigated the mechanism by which TRAIL reverses multidrug resistance, the role of c-myc in modulating the death receptors DR4 and DR5 and the relationship between cisplatin and cytochrome c (cyt c) release in SGC7901/VCR and SGC7901/DDP cells. We found that after treatment with TRAIL, the DNA-PKcs/Akt/GSK-3β pathway, which is positively correlated with the levels of MDR1 and MRP1, was significantly inhibited and that this tendency can be abolished by Z-DEVD-FMK (a specific caspase 3 inhibitor). We also found that suppression of c-myc by siRNA reduced the expression of DR4 and DR5 and that transfection with a pAVV-c-myc expression vector increased the expression of DR4 and DR5. Moreover, cisplatin increased the expression of c-myc in the presence of TRAIL, and there is a clear increase in cyt c release from mitochondria with the increasing concentrations of cisplatin. Meanwhile, the intrinsic death receptor pathway of caspase 9, as well as the common intrinsic and extrinsic downstream target, caspase 3, was potently activated by the release of cyt c. Together, we conclude that in TRAIL-treated MDR gastric carcinoma cells, cisplatin induces the death receptors DR4 and DR5 through the up-regulation of c-myc and strengthens the activation of caspases via promoting the release of cyt c. These effects would then be responsible for the TRAIL sensitization effect of cisplatin.

Identification of potential targets for diallyl disulfide in human gastric cancer MGC-803 cells using proteomics approaches

Diallyl disulfide (DADS) is characterized as an effective agent for the prevention and therapy of cancer, however, mechanisms regarding its anticancer effects are not fully clarified. In the present study, we compared the protein expression profile of gastric cancer MGC-803 cells subjected to DADS treatment with that of untreated control cells to explore potential molecules regulated by DADS. Using proteomic approaches, we identified 23 proteins showing statistically significant differences in expression, including 9 upregulated and 14 downregulated proteins. RT-PCR and western blot analysis confirmed that retinoid-related orphan nuclear receptor α (RORα) and nM23 were increased by DADS, whereas LIM kinase-1 (LIMK1), urokinase-type plasminogen activator receptor (uPAR) and cyclin-dependent kinase-1 (CDK1) were decreased. DADS treatment and knockdown of uPAR caused suppression of ERK/Fra-1 pathway, downregulation of urokinase-type plasminogen activator (uPA), matrix metalloproteinase-9 (MMP-9) and vimentin, and upregulation of tissue inhibitor of metalloproteinase-3 (TIMP-3) and E-cadherin, concomitant with inhibition of cell migration and invasion. Moreover, knockdown of uPAR potentiated the effects of DADS on MGC-803 cells. These data demonstrate that downregulation of uPAR may partially be responsible for DADS-induced inhibition of ERK/Fra-1 pathway, as well as cell migration and invasion. Thus, the discovery of DADS-induced differential expression proteins is conducive to reveal unknown mechanisms of DADS anti-gastric cancer.

Cyclin-dependent kinase 5 decreases in gastric cancer and its nuclear accumulation suppresses gastric tumorigenesis

PURPOSE

As a cyclin-independent atypical CDK, the role of CDK5 in regulating cell proliferation in gastric cancer remains unknown.

EXPERIMENTAL DESIGN

Expression of CDK5 in gastric tumor and paired adjacent noncancerous tissues from 437 patients was measured by Western blotting, immunohistochemistry, and real-time PCR. The subcellular translocation of CDK5 was monitored during gastric cancer cell proliferation. The role of nuclear CDK5 in gastric cancer tumorigenic proliferation and ex vivo xenografts was explored. Furthermore, by screening for compounds in the PubChem database that disrupt CDK5 association with its nuclear export facilitator, we identified a small molecular (NS-0011) that inhibits gastric cancer cell growth.

RESULTS

CDK5 level was significantly decreased in the majority of gastric tumor tissues, and the reduction of CDK5 correlated with the severity of gastric cancer based on tumor and lymph node metastasis and patient 5-year fatality rate. Nuclear localization of CDK5 was found to be significantly decreased in tumor tissues and gastric cancer cell lines, whereas exogenously expression of nucleus-targeted CDK5 inhibited the proliferation and xenograft implantation of gastric cancer cells. Treatment with the small molecule NS-0011, which increases CDK5 accumulation in the nucleus, suppressed both cancer cell proliferation and xenograft tumorigenesis.

CONCLUSIONS

Our results suggest that low CDK5 expression is associated with poor overall survival in patients with gastric cancer, and nuclear accumulation of CDK5 inhibits the proliferation and tumorigenicity of human gastric cancer cells.

Prognostic significance of the recurrence pattern and risk factors for recurrence in patients with proximal gastric cancer who underwent curative gastrectomy

Proximal gastric cancer has a high propensity of early recurrence after curative resection due to high incidence of lymph node involvement. In the present study, we aimed to investigate the pattern and time of recurrence and to evaluate the risk factors for recurrence of patients with proximal gastric cancer. Between 2005 and 2013, 99 patients with recurrent proximal gastric cancer who underwent radical gastrectomy were retrospectively analyzed. The prognostic significance of the pattern and the time of recurrence and the relationship between the pattern of recurrence and the other clinicopathological factors were evaluated. The median time to recurrence was 24 months; 45.5 % of patients relapsed within 2 years. Forty-three (43.4 %) patients indicated hematogenous recurrence and 41 (41.4 %) patients revealed peritoneal recurrence with the most predominant patterns. The median progression-free survival (PFS) time for patients with locoregional recurrence was significantly better than that of patients with peritoneal recurrences, hematogenous recurrences, and distant lymph nodes (32.2 vs. 18.9 vs. 18.2 vs. 9.7 months, p = 0.005, respectively). Moreover, the median overall survival (OS) interval for patients with distant lymph nodes recurrence was significantly worse than that of patients with locoregional, peritoneal, and hematogenous recurrences (13.5 vs. 48.5 vs. 31.4 vs. 29.9 months, p = 0.006, respectively). The presence of lymph node metastasis (p = 0.004) and surgery type (p = 0.04) for PFS and the time of recurrence (p = 0.033), lymph node metastasis (p = 0.03), and surgery type (p = 0.04) for OS were found to be independent prognostic factors by multivariate analysis. Logistic regression analysis indicated that the presence of lymph node metastasis and surgery type were independent risk factors for predicting the occurrence of early recurrence (p = 0.001, OR 0.48 and p = 0.028, OR 0.41, respectively). The median OS time of early recurrence patients was significantly shorter than that of patients with late recurrence (16.6 vs. 55.2 months, p < 0.001). Furthermore, proximal gastrectomy, poorly differentiated histology, advanced pT stage, and lymph node metastasis were significantly associated with early recurrence. Our results showed that lymph node metastasis and surgery type were independent risk factors for prediction of early recurrence in proximal gastric cancer. Thus, total gastrectomy with regional lymph node dissection may be a suitable treatment option for proximal gastric cancer patients with tumors that have high risk features for recurrence.

Inhibition of microRNA-17/20a suppresses cell proliferation in gastric cancer by modulating UBE2C expression

microRNAs (miRNAs) are small non-coding RNAs that potentially play a critical role in carcinogenesis. Increasing evidence indicates that the miR-17/20 cluster is upregulated in numerous types of human cancers including gastric cancer which suggests that the miR-17/20 cluster may play an important role in tumorigenesis. However, its role in gastric cancer carcinogenesis remains poorly defined due to the lack of target gene information. The aim of the present study was to investigate the target genes of the miR-17/20 cluster and their role in the tumor growth of gastric cancer. We found that both miR-17 and miR-20a (miR-17/20a) target the UBE2C gene in gastric cancer cells. Luciferase assay, qRT-PCR and western blot analysis confirmed that UBE2C is a direct target of miR‑17/20a in gastric cancer cells. Our results showed that the expression of UBE2C was positively regulated by miR-17/20a at both the mRNA and protein levels. Moreover, miR-17/20a was upregulated and positively associated with UBE2C in the gastric cancer tissues when compared to the adjacent nontumor tissues. Inhibition of miR-17/20a in gastric cancer cells was statistically correlated with a decrease in cell growth. These results demonstrate that upregulation of miR-17/20a promotes gastric cancer cell growth by targeting UBE2C and inhibition of their levels is a potentially promising therapeutic strategy for gastric cancer.

Significant differences in the clinicopathological characteristics and survival of gastric cancer patients from two cancer centers in china and Korea

PURPOSE

To compare the clinicopathological data and long-term survival of gastric cancer patients in China and Korea.

MATERIALS AND METHODS

Patients who had undergone gastrectomy for gastric cancer between 1998 and 2009 in 2 high-volume institutions in both China (n=1,637) and Korea (n=2,231) were retrospectively evaluated. Clinicopathological variables, overall survival (OS), progression-free survival (PFS), and surgery-related complications were assessed for all patients and compared between the 2 institutions.

RESULTS

Chinese patients included in the study were significantly older and had a significantly lower body mass index (BMI) than the Korean patients. Esophagogastric junction tumors were more frequent in Chinese patients. However, the number of patients with stage I gastric cancer, the number of harvested lymph nodes, and the number of total gastrectomies were significantly higher in the Korean population. Korean patients also presented with fewer undifferentiated tumors than Chinese patients. Furthermore, Korean patients had prolonged OS and PFS for stage III cancers only. BMI, tumor-node-metastasis (TNM) stage, tumor invasion, number of positive lymph nodes, and distant metastases were all independent factors affecting OS and PFS.

CONCLUSIONS

Although China and Korea are neighboring Asian countries, the clinicopathological characteristics of Chinese patients are significantly different from those of Korean patients. Korean gastric cancer patients had longer OS and PFS than Chinese patients. Influencing factors included TNM stage, tumor invasion, and lymph node metastasis.

Association of interleukin 22 polymorphisms with gastric cancer risk

Interleukin (IL)-22 has been implicated in inflammation and tumorigenesis. To date, no studies have investigated the role of IL-22 polymorphism in the carcinogenesis of gastric cancer (GC). In this study, we aimed to investigate the association of IL-22 polymorphisms with the risk of GC in a Chinese population. One hundred eight GC patients and 110 healthy controls were included in the study. IL-22 rs1179251, rs2227485, and rs2227473 polymorphisms were determined by PCR amplification and DNA sequencing. Haplotypes were constructed, and a possible association of these haplotypes with GC was assessed. The distribution of IL-22 rs1179251 polymorphism with clinical parameters was also analyzed. The IL-22 rs1179251 polymorphism was significantly associated with an increased risk of GC (p < 0.05). Stratified analysis revealed that rs1179251 was associated with advanced stages, lymph node metastases, and distant metastases of GC (p < 0.05). No associations were found between rs2227485 and rs2227473 and the risk of GC (p > 0.05). Three possible haplotypes (C(rs1179251)-C(rs2227485)-G(rs2227485), C(rs1179251)-T(rs2227485)-G(rs2227485), and G(rs1179251)-T(rs2227485)-A(rs2227485)) were identified, but no associations were found between these and the risk of GC (p > 0.05). In summary, our study demonstrates that the rs1179251 polymorphism of IL-22 was associated with an increased risk of GC and may influence the progression of GC. Future larger studies with other ethnic populations are required to confirm these findings.

Lung Cancer Mortality Among Women in Xuan Wei, China

The identification of spatial clusters of lung cancer mortality can be a useful instrument in detecting locations with high risk of this disease. This study compared 2 methods for identifying spatial clusters of village-level women lung cancer mortality rates in Xuan Wei. One used a local indicator of spatial association to detect which groups of neighboring villages had lung cancer mortality rates that were significantly related to each other. The other was a spatial scan technique that calculated a maximum likelihood ratio of lung cancer deaths relative to the underlying population in order to identify the group of villages with relatively higher risk. As each technique based its cluster detection process on its own criteria, different clusters of villages were identified. However, the overlapping indicated that the 2 methods illustrated different components of the same clusters. These spatial analytic techniques were complementary to each other and can be used jointly rather than separately.

PPARγ suppressed Wnt/β-catenin signaling pathway and its downstream effector SOX9 expression in gastric cancer cells

Wnt signaling pathway activation plays a critical role in biological processes of tumor progression. SOX9 belongs to the sry-related high-mobility group box (SOX) family and is a key transcription factor in the development and differentiation of multiple cell lineages. The purpose of this study was to investigate whether suppression of Wnt signaling pathway by PPARγ gene affects target SOX9 gene expression. The pEGFP-N1-PPARγ overexpression recombinant plasmid was structured by molecular biology technology. The overexpression plasmid and empty vector pEGFP-N1 were transfected into three types of human gastric cancer cell lines, with different levels of differentiation, MKN-28, SGC-7901 and BGC-823. The PPARγ, β-catenin and SOX9 mRNA levels and proteins were examined by real-time PCR and Western blot analysis. The pEGFP-N1-PPARγ recombinant plasmid was constructed and transfected into MKN-28, SGC-7901 and BGC-823 successfully. High expression of PPARγ (p < 0.05) for transfection recombinant plasmid group induced obviously decreased expression of β-catenin (p < 0.05), whereas SOX9 expression decreased significantly (p < 0.05) compared with the transfection empty vector group and normal comparison group. PPARγ can suppress β-catenin expression in Wnt signaling pathway and its downstream effector SOX9 expression in gastric cancer cells.