Incidence and mortality of gastric cancer in China

Overexpression of forkhead box M1 and urokinase-type plasminogen activator in gastric cancer is associated with cancer progression and poor prognosis

Forkhead box M1 (FOXM1) and urokinase-type plasminogen activator (uPA) are overexpressed and associated with the pathogenesis of multiple types of human malignancy. The aims of the present study were to investigate FOXM1 and uPA expression levels in human gastric cancer using tissue microarray techniques; determining their association with clinicopathological characteristics as well as their prognostic value. Tissue microarray blocks, comprising 436 gastric cancer cases and 92 non-cancerous adjacent normal gastric tissues, were analyzed for FOXM1 and uPA protein expression levels using immunohistochemistry. The results were analyzed statistically in association with various clinicopathological characteristics and overall survival rates. FOXM1 and uPA were detected in 78.67 (343/436) and 83.26% (363/436) of cancer samples, respectively. FOXM1 and uPA were not expressed in the 92 normal gastric tissue samples. In gastric cancer, FOXM1 and uPA levels were associated with tumor size, depth of invasion, tumor-node-metastasis (TNM) stage, lymph node metastasis, vessel invasion and distant metastases. The overall survival rate was significantly decreased in patients expressing FOXM1 and uPA compared with FOXM1- and uPA-negative patients. Coxs multivariate analysis revealed that age, depth of invasion and expression levels of FOXM1 and uPA are independent predictors of survival in patients with gastric cancer. These results indicated that increased FOXM1 and uPA expression levels are associated with the invasive and metastatic processes in human gastric cancer, and inversely associated with patient prognosis. Therefore, FOXM1 and uPA may serve as novel prognostic markers independent of, but supplementing, the TNM staging system.

Association between ALDH2 rs671 G>A polymorphism and gastric cancer susceptibility in Eastern Asia

To date, the relationship between the aldehyde dehydrogenases-2 (ALDH2) rs671 G>A (Glu504Lys) polymorphism and gastric cancer (GC) risk has not been thoroughly elucidated. To derive a more precise estimation of the effect of the ALDH2 rs671 G>A polymorphism on GC, we conducted this meta-analysis. We searched for qualified studies in the Embase, PubMed, Wang Fan and China National Knowledge Infrastructure databases. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the association. A total of 6,421 GC patients and 8,832 control subjects were included in the present study. The pooled results indicated no significant relationship between the ALDH2 rs671 G>A polymorphism and GC susceptibility in all genetic models. A stratified analysis by country showed that the ALDH2 rs671 G>A polymorphism might be a risk factor for GC in Japan (Allele model: P_unadjusted = 0.034; Dominant model: P_unadjusted = 0.040); however, the result was nonsignificant when the Bonferroni correction and false discovery rate (FDR) were applied. In subgroup analyses by drinking status in the dominant model, our study revealed that the ALDH2 rs671 G>A polymorphism significantly increased the risk of GC for drinkers (dominant model: P < 0.001). No relationship between the ALDH2 rs671 G>A polymorphism and GC risk was observed in any other subgroup. Our present study indicated no association between the ALDH2 rs671 G>A polymorphism and GC risk in Eastern Asian populations. However, the ALDH2 rs671 G>A polymorphism can significantly increase GC risk for drinkers.

Blocking autophagy enhances the pro-apoptotic effect of bufalin on human gastric cancer cells through endoplasmic reticulum stress

Bufalin has been used to treat cancer for several years. However, the molecular mechanisms for its anti-tumor function are not fully understood. This work aimed to investigate the effect of bufalin on the proliferation and apoptosis of human gastric cancer (HGC) cells and the roles of endoplasmic reticulum (ER) stress and autophagy in bufalin-induced apoptosis. HGC cell lines, SGC7901 and BGC823, were treated with different concentrations of bufalin or 80 nmol/l bufalin for 1, 2, 3 and 4 days. Cell counting kit-8 (CCK-8) assay and direct cell counting method were used to detect proliferation. Cell cycle arrest and apoptosis was detected using flow cytometry. Protein levels of caspase-3, -8, Bax/Bcl-2, Beclin-1, LC3, inositol-requiring enzyme 1 (IRE1) and C/EBP homologous protein (CHOP) were determined using western blotting. Autophagy was blocked using 3-methyladenine (3MA) or Atg5 siRNA to evaluate the effect of autophagy on bufalin-induced apoptosis. The IRE1 and CHOP were knocked down using specific siRNA to determine the pathway involved in bufalin-induced autophagy. It was found that bufalin significantly suppressed proliferation of SGC7901 and BGC823 cells and induced apoptosis in a time- and dose-dependent manner. The mechanism responsible for bufalin-induced apoptosis was the formation of ER stress via the IRE1-JNK pathway. Moreover, autophagy was activated during ER stress, and blocking autophagy significantly exacerbated bufalin-induced apoptosis.

Summary: Bufalin suppressed human gastric cancer cells and induced apoptosis. The mechanism was related to ER stress formation via the IRE1-JNK pathway. Blocking autophagy exacerbated bufalin-induced apoptosis.

Mastl overexpression is associated with epithelial to mesenchymal transition and predicts a poor clinical outcome in gastric cancer

Microtubule-associated serine/threonine kinase like (Mastl) is deregulated in a number of types of human malignancy and may be a kinase target for cancer treatment. The aim of the present study was to determine the Mastl expression in gastric cancer and to clarify its clinical and prognostic significance. Immunohistochemistry was performed on a cohort of 126 postoperative gastric cancer samples to detect the expression of Mastl and two epithelial to mesenchymal transition (EMT) markers, epithelial-cadherin and Vimentin. The χ² test, Kaplan-Meier estimator analysis and Cox's regression model were used to analyze the data. Upregulated Mastl protein expression was observed in the gastric cancer tissues compared with that in the adjacent non-cancerous gastric tissues. Increased Mastl expression was identified in 54/126 (42.9%) gastric cancer samples, and was significantly associated with lymph node metastasis, tumor relapse, EMT status and poor overall survival. Additional analysis demonstrated that the Mastl expression level stratified the patient outcome in stage III, but not stage II tumor subgroups. Cox's regression analysis revealed that increased Mastl expression was an independent prognostic factor for patients with gastric cancer. Mastl expression may be a valuable prognostic marker and a potential target for patients with gastric cancer.

The relationship between stromal cell derived SPARC in human gastric cancer tissue and its clinicopathologic significance

Background

We aimed to investigate the cellular source of secreted protein acidic and rich in cysteine (SPARC) in gastric cancer tissues and the relationship between SPARC expression and its prognostic significance.

Methods

The expression of SPARC in 365 primary advanced gastric adenocarcinomas and 39 non-cancerous tissues was evaluated by immunohistochemical staining. Double-immunofluorescence staining was used to reveal the cellular source of SPARC in tumor tissues. Western blotting and immunofluorescence staining were applied for verifying the endogenous expression of SPARC in human cell lines of gastric cancer and fibroblast.

Results

Higher positivity of SPARC was observed in gastric cancer tissues than non-cancerous gastric tissues (P=0.000). The positivity of SPARC was related to age (P=0.032), tumor location (P=0.018), depth of tumor invasion (P=0.011), nodal metastasis (P=0.023), TNM stage (P=0.034), the differentiation degree (P=0.006) and pathological type (P=0.002) of gastric cancer. SPARC in gastric cancer tissues was mainly expressed by cancer-associated fibroblasts. SPARC also appeared in neovascular endothelial cells and a few tumor-associated macrophages. The endogenous expression of SPARC in fibroblasts was suppressed by mucus-producing gastric adenocarcinoma cells(MKN-45). Increased SPARC expression in gastric cancer tissue was suggestive of a shorter cumulative survival in the patients with gastric adenocarcinoma, though this difference was not statistically significant(P>0.05).

Conclusion

SPARC in human gastric cancer tissue was derived from the stromal cells and was mainly produced by cancer-associated fibroblasts. Production of SPARC in fibroblasts was reduced by the mucus-producing gastric adenocarcinoma cells.

Human Epidermal Growth Factor Receptor-2 in Sri Lankan Gastric Carcinoma Patients with Clinicopathological Association and Survival

BACKGROUND

HER2 protein expression indicates adverse prognosis in gastric adenocarcinoma (GCa). GCa HER2 positivity ranges from 10 to 22.8%. Similar data are scarce in South Asia and unavailable in Sri Lanka.

AIM

To evaluate HER2 protein expression, its clinicopathological relationship and survival in a Sri Lankan GCa cohort.

METHODS

One hundred consecutive GCa patients were recruited prospectively for 2 years. Histological diagnosis was confirmed on endoscopic biopsies/gastrectomy specimens. Clinicopathological and overall survival data were collected. HER2 expression was assessed using immunohistochemistry. 2+ and 3+ scores were considered positive. HER2 expression and clinicopathological parameters were analyzed by Chi-squared test and multivariate analysis with logistic regression using SPSS-21. Kaplan-Meier method and log-rank test were used for survival analysis.

RESULTS

Study includes 56 biopsies and 44 resections. Male/female ratio was 1.9:1. Mean age of diagnosis was 61.1 years (range 32-82). Majority tumors were proximally located (58%). HER2 positivity was 9%. Even though intestinal subtype predominated HER2 positivity was mostly among diffuse variant (14.8%). In multivariate analysis, mitotic count >5/hpf, high nuclear grade and tumor necrosis were significantly associated with HER2 positivity, while poor differentiation, signet cells, extracellular mucin, perineural invasion and pathological nodal metastasis (all p < 0.05) showed a correlation in univariate analysis. Mean follow-up duration was 37.4 weeks (range 0-104). HER2 positivity was associated with a significantly lower median overall survival (p = 0.046).

CONCLUSION

GCa HER2 positivity was 9%, associated with a lower median overall survival. Adverse histological features had a positive correlation with HER2 positivity. These histological features could direct patients for confirmatory HER2 testing in limited resource settings.

VPS52 induces apoptosis via cathepsin D in gastric cancer

Vacuolar protein sorting (VPS) genes encode a class of proteins involved in vesicular trafficking. Growing evidence suggests that VPS proteins play roles in tumor biology. Vacuolar protein sorting 52 (VPS52) is involved in retrograde transport of endosomes, and its roles in cancers have not been explored. This study investigated the genetic alterations, protein changes, biological role, and molecular mechanism of VPS52 in gastric cancer. Loss of heterozygosity of VPS52 was detected in 52.9% (9/17) of gastric cancer samples. Twenty-five percent (5/20) gastric cancer samples contained somatic stop-gain mutation of VPS52, two of which also had simultaneous loss of heterozygosity. Lack of VPS52 protein expression in gastric cancer tissue was found compared with pericancerous tissue and was significantly correlated with more advanced TNM staging and shorter 3-year overall survival. Overexpression of VPS52 significantly reduced viability and increased apoptosis in gastric cancer cells in vitro and reduced tumor volume and tumor weight in xenograft model in vivo. Activation of the cathepsin D/Bax/cytochrome C/caspase 9/caspase 3 pathway was detected in gastric cancer cells overexpressing VPS52. Collectively, VPS52 is a tumor suppressor gene in gastric cancer and could be used as a biomarker. VPS52 adenovirus could be a novel anti-tumor reagent for future gene therapy.

KEY MESSAGES

Loss of heterozygosity and stop-gain mutation of VPS52 were found in gastric cancer. Negative expression of VPS52 significantly correlated with poor prognosis. VPS52 inhibited viability and induced apoptosis of gastric cancer cells in vitro. VPS52 reduced tumor volume and tumor weight in vivo. VPS52 activated the apoptotic pathway through cathepsin D in gastric cancer cells.

A global burden of gastric cancer: the major impact of China

Gastric cancer (GC) is a highly aggressive cancer and a major cause of cancer-related deaths worldwide. Approximately half of the world's GC cases and deaths occur in china. GC presents challenges in early diagnosis and effective therapy due to a lack of understanding of the underlying molecular biology. The primary goals of this review are to outline current GC research in china and describe future trends in this field. Areas covered: This review mainly focuses on a series of GC-related advances China has achieved. Considerable progress has been made in understanding the role of H. pylori in GC by a series of population-based studies in well-established high-risk areas; A few germline and somatic alterations have been identified by 'omics' studies; Studies on the mechanisms of malignant phenotypes have helped us to form an in-depth understanding of GC and advance drug discovery. Moreover, identification of potential biomarkers and targeted therapies have facilitated the diagnosis and treatment of GC. However, many challenges remain. Expert commentary: To combat GC, sufficient funding is important. More attention should be paid on early diagnosis and the discovery of novel efficient biomarkers and the development of biomarker-based or targeted therapeutics in GC.

Roles of p38 and JNK protein kinase pathways activated by compound cantharidin capsules containing serum on proliferation inhibition and apoptosis of human gastric cancer cell line

The aim of the present study was to investigate the inhibitory effect of compound cantharides capsules (CCCs) on the viability and apoptosis of human gastric cancer cell lines, BGC-823 and SGC-7901, and to detect its regulation of gene expression levels, as well as its inhibition mechanisms. Each cell line was grouped into a control group, CCC serum group, 5-fluorouracil (5-FU) group, combination therapy group (CCC serum + 5-FU) and serum control group. Growth curves were measured and flow cytometry was used to detect cell apoptosis and cell viability. The mRNA expression level of proliferation-related C-MYC and p53 genes were assayed by reverse transcription-quantitative polymerase chain reaction. Protein phosphorylation levels of proliferating cell nuclear antigen, p38 mitogen-activated protein kinase, extracellular signal-related kinase 1/2, c-Jun N-terminal kinase (JNK) and IκB were assayed by western blotting. The combined CCC serum and 5-FU group exhibited a higher inhibition rate in both cell lines and CCC serum therapy demonstrated a similar effect to 5-FU treatment, as demonstrated in the MTT and cell growth assay. Combined therapy significantly decreased the C-MYC mRNA expression levels and increased p53 mRNA expression levels (P<0.05). Combined therapy of 5-FU and CCC was more significant compared with CCC serum or 5-FU only (P<0.05). P38 and JNK-related protein phosphorylation are involved in apoptosis initiated by CCC combined 5-FU therapy. Combined therapy was able to significantly inhibit human gastric cancer cell growth (P<0.05), and advance cell apoptosis compared with CCC serum only. CCC serum resulted in downregulation of the c-Myc gene and upregulation of the p53 gene. p38 and JNK-related protein phosphorylation is involved in the inhibition of cell viability and apoptosis of human gastric cancer cell lines.

Suppression of midkine gene promotes the antitumoral effect of cisplatin on human gastric cancer cell line AGS in vitro and in vivo via the modulation of Notch signaling pathway

Midkine (MK) is reported to be associated with the clinical stages and distant metastases in gastric cancer, and to positively regulate the proliferation of human gastric cancer cells. However, the possible mechanisms of MK in the development of gastric cancer are still not fully clarified. In this study, the therapeutic effect of MK inhibition in gastric cancer in vivo and in vitro was investigated, by knock-down of MK expression with a small interfering RNA (siRNA). MK was expressed in gastric carcinoma tissues and cancer cells. The cytotoxic effect of cisplatin on AGS cells in vitro was attenuated by recombinant human MK, but was promoted by suppressing MK expression via downregulating the Notch signaling pathway-related proteins (Notch 1, Notch 2, Delta-like 1 and Jagged 1). Suppression of MK expression also promoted the inhibitory effect of cisplatin on AGS cells in vivo. In concusion, suppression of midkine gene promoted the antitumoral effect of cisplatin on human gastric cell line AGS in vitro and in vivo via Notch signaling pathway.

MicroRNA-630 Suppresses Epithelial-to-Mesenchymal Transition by Regulating FoxM1 in Gastric Cancer Cells

In the present study, we investigated the functional role of microRNA (miR)-630 in epithelial-to-mesenchymal transition (EMT) of gastric cancer (GC) cells, as well as the regulatory mechanism. Cells of human GC cell line SGC 7901 were transfected with miR-630 mimic or miR-630 inhibitor. The transfection efficiency was confirmed by qRT-PCR. Cell migration and invasion were determined by Transwell assay. Protein expression of E-cadherin, vimentin, and Forkhead box protein M1 (FoxM1) was tested by Western blot. Moreover, the expression of FoxM1 was elevated or suppressed, and then the effects of miR-630 abnormal expression on EMT and properties of migration and invasion were examined again, as well as protein expression of Ras/phosphoinositide 3-kinase (PI3K)/AKT related factors. The results showed that (i) the EMT and properties of migration and invasion were statistically decreased by overexpression of miR-630 compared to the control group but markedly increased by suppression of miR-630. However, (ii) abnormal expression of FoxM1 reversed these effects in GC cells. Moreover, (iii) expression of GTP-Rac1, p-PI3K, and p-AKT was decreased by miR-630 overexpression but increased by FoxM1 overexpression. (iv) The decreased levels of GTP-Rac1, p-PI3K, and p-AKT induced by miR-630 overexpression were dramatically elevated by simultaneous overexpression of FoxM1. In conclusion, our results suggest that miR-630 might be a tumor suppressor in GC cells. MiR-630 suppresses EMT by regulating FoxM1 in GC cells, supposedly via inactivation of the Ras/PI3K/AKT pathway.

MicroRNA-508-5p suppresses metastasis in human gastric cancer by targeting S-phase kinase‑associated protein 2

S-phase kinase-associated protein 2 (SKP2), a potent oncogene was revealed to be upregulated in gastric cancer (GC) tissue samples, in which SKP2 was inversely correlated with microRNA (miR)‑508‑5p transcripts. In present study, the functional effect of miR‑508‑5p on SKP2 and its metastatic potential were investigated in SGC‑7901 GC cells. Significant downregulation of the miR‑508‑5p transcript was associated with the progression of GC. Furthermore, the overexpression of miR‑508‑5p was demonstrated to inhibit the proliferation, migration and invasion of SGC‑7901 cells, as well as induced cell apoptosis and cell cycle arrest at the G0/G1 phase in vitro. The overexpression of miR‑508‑5p was able to downregulate the expression of the SKP2 oncogene, through a mechanism by which miR‑508‑5p directly targeted the SKP2 gene. Thus, regulating transcriptional and post‑transcriptional SKP2 expression, as demonstrated using luciferase reporter assays, reverse transcription‑quantitative polymerase chain reaction analysis and immunoblotting assays. The results of the present study identified that miR‑508‑5p functionally affects the SKP2 gene and reduces metastatic potential in GC, suggesting a novel role of miR‑508‑5p in the regulation of SKP2 and cell cycle.

Third-line chemotherapy in advanced gastric cancer: A systematic review and meta-analysis

BACKGOUND

Little information regarding to the survival advantage of third-line chemotherapy in advanced gastric cancer patients is available. The current study is designed to systematically review and perform meta-analysis on the effect of third-line chemotherapy on progressive or recurrent gastric cancer treatment.

METHODS

After thorough searching of online databases, total 20 articles were included into qualitative systematic review and 6 of them were used to conduct qualitative meta-analysis.

RESULTS

It was found that the third-line chemotherapy was superior to placebo or best supportive care in terms of prolonging median oval survival (OS) length and progress free survival (PFS) length (Hedges's g for OS = -0.315 ± 0.077, P < .001; and for PFS = -0.382 ± 0.098, P < .001). In addition, the third-line chemotherapy was favored (Hedges's g = 0.848, P < .001) in terms of overall survival rate (Hazard ratio = 0.679, 95% confidence interval: 0.565-0.816, P < .001) or tumor free survival rate (Hazard ratio = 0.561, 95% confidence interval: 0.444-0.709, P < .001).

CONCLUSION

The third-line chemotherapy is superior to the best supportive care in advanced gastric cancer patients who had been pretreated with first-line and second-line chemotherapy.

Aberrant CpG Island Shore Region Methylation of CAV1 Is Associated with Tumor Progression and Poor Prognosis in Gastric Cardia Adenocarcinoma

BACKGROUND AND AIMS

Caveolin-1 (CAV1) is a multifunctional scaffolding protein and plays an important role in tumorigenesis. However, the epigenetic changes of CAV1 in gastric cardia adenocarcinoma (GCA) have not been investigated so far. The purpose of this study was to clarify the contribution of critical CpG sites in CAV1 to progression/prognosis of GCA and to further elucidate the effect of critical CpG sites on the ectopic expression of β-catenin in GCA.

METHODS

Methylation-specific polymerase chain reaction (MSP) and bisulfite genomic sequencing (BGS) methods were, respectively, applied to examine the methylation status of CAV1. RT-PCR and immunohistochemistry methods were used to determine the mRNA and protein expression of CAV1 and β-catenin.

RESULTS

Decreased mRNA and protein expression of CAV1 were observed in GCA tumor tissues and were associated with hypermethylation of CpG island shore and transcription start site (TSS) regions in CAV1. Hypermethylation of the other two regions within CpG islands in CAV1 was observed both in tumor and corresponding adjacent tissues but was not related to the transcriptional inhibition of CAV1. The methylation status of CpG island shore region in CAV1 was associated with the ectopic expression of β-catenin and was independently associated with survival in GCA patients.

CONCLUSIONS

Hypermethylation of CpG island shore and TSS regions is cancer specific and is closely associated with reduced expression of CAV1. The CpG island shore methylation of CAV1 may play an important role in progression of GCA and may serve as a prognostic methylation biomarker for GCA patients.

Racial and Ethnic Variability in the Prevalence and Incidence of Comorbidities Associated with Gastric Cancer in the United States

PURPOSE

Comorbidities are known to impact quality of life, treatment choices, and survival. Our objectives were to characterize comorbid conditions in a cohort of elderly gastric cancer patients and to determine if there is variability in the prevalence or incidence of the comorbid conditions across racial/ethnic groups.

METHODS

A total of 12,612 individuals, ≥66 years of age, diagnosed with gastric cancer between 2000 and 2007, and an equal number of gender- and region-matched cancer-free individuals, were identified using the National Cancer Institute's Surveillance, Epidemiology, and End Results registry linked to Medicare claims in the United States. The prevalence (%) in the year before diagnosis and the 12-month incidence rates after diagnosis were estimated for 32 chronic and ten acute comorbid conditions for the entire cohort and by race/ethnicity (Asian, Black, Hispanic, White, and other) and Asian subgroups (e.g., Chinese, Filipino, Japanese, Pacific Islander).

RESULTS

White and Black cases exhibited the highest prevalence of most comorbid conditions. Asian and Pacific Islander cases exhibited the lowest. There was substantial variability in the 12-month incidence of the comorbidities across the racial/ethnic groups. Electrolyte disorder was the most common incident condition among Whites and Blacks. With the exception of Whites, anemia was the most common incident condition in all racial and ethnic groups 180 days following chemotherapy.

CONCLUSIONS

There is variability in the prevalence and incidence in comorbidities across racial/ethnic groups.

Expression of CRM1 and CDK5 shows high prognostic accuracy for gastric cancer

AIM

To evaluate the predictive value of the expression of chromosomal maintenance (CRM)1 and cyclin-dependent kinase (CDK)5 in gastric cancer (GC) patients after gastrectomy.

METHODS

A total of 240 GC patients who received standard gastrectomy were enrolled in the study. The expression level of CRM1 and CDK5 was detected by immunohistochemistry. The correlations between CRM1 and CDK5 expression and clinicopathological factors were explored. Univariate and multivariate survival analyses were used to identify prognostic factors for GC. Receiver operating characteristic analysis was used to compare the accuracy of the prediction of clinical outcome by the parameters.

RESULTS

The expression of CRM1 was significantly related to size of primary tumor (P = 0.005), Borrmann type (P = 0.006), degree of differentiation (P = 0.004), depth of invasion (P = 0.008), lymph node metastasis (P = 0.013), TNM stage (P = 0.002) and distant metastasis (P = 0.015). The expression of CDK5 was significantly related to sex (P = 0.048) and Lauren's classification (P = 0.011). Multivariate Cox regression analysis identified that CRM1 and CDK5 co-expression status was an independent prognostic factor for overall survival (OS) of patients with GC. Integration of CRM1 and CDK5 expression could provide additional prognostic value for OS compared with CRM1 or CDK5 expression alone (P = 0.001).

CONCLUSION

CRM1 and CDK5 co-expression was an independent prognostic factors for GC. Combined CRM1 and CDK5 expression could provide a prognostic model for OS of GC.

Leptin-LepRb Expressed in Gastric Cancer Patients and Related to Cancer-Related Depression

Depression is the most common psychiatric disorder among cancer patients. Studies have not only highlighted that leptin and its receptor (LepRb) are independent poor prognostic factors in gastric cancer (GC) patients but also shown that the leptin-LepRb is necessary for antidepressant-like behaviors. In this study, we examined the serum and tissue leptin-LepRb expression in GC patients. Enzyme-linked immunosorbent assay showed that depressive GC patients had significantly higher serum leptin-LepRb than healthy donors. Leptin-LepRb levels in GC tissues were also significantly higher than in matched paracarcinoma tissues using real-time RT-PCR. Moreover, we observed that both serum and tissue leptin-LepRb were significantly higher in depressive GC patients than those in nondepressive GC patients. Further, the patients with high tumor stage tend to have higher leptin-LepRb mRNA levels than that with low tumor stage. Together, our findings suggest that leptin-LepRb plays an important role in the pathogenesis and depression in GC. Leptin-LepRb therefore could be a potential diagnostic marker and therapeutic target in GC patients with depression.

UBE2C induces EMT through Wnt/β‑catenin and PI3K/Akt signaling pathways by regulating phosphorylation levels of Aurora-A

The ubiquitin-conjugating enzyme 2C (UBE2C) is the key component in the ubiquitin proteasome system (UPS) by partnering with the anaphase‑promoting complex (APC/C). A high UBE2C protein expression level has been reported in various types of human tumors. However, little is known about the precise mechanism by which UBE2C expression is downregulated in gastric cancer. We found in MGC‑803 and SGC‑7901 gastric cancer cells UBE2C‑deficient G2/M phase arrest in the cell cycle and subsequently decreased gastric adenocarcinoma tumorigenesis. In the previous study, we identified Aurora-A (AURKA) as the hub gene of the gastric cancer linkage network based genome‑wide association study (eGWAS). Furthermore, knockdown of UBE2C using siRNA markedly reduced the level of phosphorylation AURKA (p‑AURKA) via Wnt/β‑catenin and PI3K/Akt signaling pathways suppressed the occurrence and development of gastric cancer. Additionally, the expression of E‑cadherin was up‑regulated and N-cadherin was downregulated in response to UBE2C knockdown and inhibits epithelial-mesenchymal transition (EMT). Collectively, our data suggest that the activity of AURKA might be regulated by UBE2C through regulating the activity of APC/C. UBE2C may be a new marker in the diagnosis of gastric cancer and may be a potential therapeutic target for the treatment of gastric adenocarcinoma.

Cancer burden with ageing population in urban regions in China: projection on cancer registry data from World Health Organization

BACKGROUND

China is facing the challenges of an expanding ageing population and the impact of rapid urbanization, cancer rates are subsequently increasing. This study focuses on the changes of the ageing population and projects the incidence of common ageing-related cancers in the urban regions in China up to 2030.

SOURCES OF DATA

Cancer incidence data and population statistics in China were extracted from the International Agency for Research on Cancer.

AREAS OF AGREEMENT

Due to improving longevity in China, continuous and remarkable increasing trends for the lung, colorectal and prostate cancers are expected.

GROWING POINTS

The rate of expanding ageing population was taken into account when predicting the trend of cancer incidence; the estimations of ageing-related cancers were more factual and significant than using the conventional approach of age standardization.

AREAS TIMELY FOR DEVELOPING RESEARCH

The incidence rates of lung, colorectal and prostate cancers will continue to rise in the future decades due to the rise of ageing population. Lifestyle modification such as cutting tobacco smoking rates and promoting healthier diets as well as cancer screening programs should be a health system priority in order to decrease the growing burden of cancer-related mortality and morbidity.

Identification of a prognostic 5-Gene expression signature for gastric cancer

PURPOSE

Gastric cancer (GC) is a major tumor throughout the world with remaining high morbidity and mortality. The aim is to generate a gene model to assess the prognoses risk of patients with GC.

METHODS

Gene expression profiling of gastric cancer patients, GSE62254 (300 samples) and GSE26253 (432 samples), was downloaded from Gene Expression Omnibus (GEO) database. Univariate survival analysis and LASSO (Least Absolute Shrinkage and Selectionator operator) (1000 iterations) of differentially expressed genes in GSE62254 was assessed using survival and glmnet in R package, respectively. Kaplan-Meier analysis on the clustering algorithm from each regression model was performed to calculate the influence to the prognosis. Random samples in GSE26253 were analyzed in multivariate and univariate survival analysis for one thousand times to calculate statistical stability of each regression model.

RESULTS

A total of 854 Genes were identified differentially expressed in GSE62254, among which 367 Genes were found influencing the prognoses. Six gene clusters were selected with good stability. Hereinto, five or more genes in 11-Gene model, TRPC1, SGCE, TNFRSF11A, LRRN1, HLF, CYS1, PPP1R14A, NOV, NBEA, CES1 and RGN, was available to evaluate the prognostic risk of GC patients in GSE26253 (P = 0.00445). The validity and reliability was validated.

CONCLUSION

In conclusion, we successfully generated a stable 5-Gene model, which could be utilized to predict prognosis of GC patients and would contribute to postoperational treatment and follow-up strategies.

STAT3 signaling drives EZH2 transcriptional activation and mediates poor prognosis in gastric cancer

BACKGROUND

STAT3 signaling plays the pivotal role in tumorigenesis through EZH2 epigenetic modification, which enhanced STAT3 activity by increased tyrosine phosphorylation of STAT3. Here, another possible feedback mechanism and clinical significance of EZH2 and STAT3 were investigated in gastric cancer (GC).

METHODS

STAT3, p-STAT3 (Tyr 705) and EZH2 expression were examined in 63 GC specimens with matched normal tissues by IHC staining. EZH2 and STAT3 were also identified in five GC cell lines using RT-PCR and western blot analyses. p-STAT3 protein was detected by western blotting. In order to investigate whether EZH2 expression was directly regulated by STAT3, EZH2 expression was further detected using siRNA for STAT3 or IL-6 stimulation, with dual luciferase reporter analyses, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assays. The clinical significance of STAT3, p-STAT3 and EZH2 expression was evaluated by multi-factor COX regression and Kaplan-Meier analyses.

RESULTS

Hyper-activation of STAT3, p-STAT3 and EZH2 expression were observed in GC cells and tissues. STAT3 signaling was correlated with EZH2 expression in GC (R = 0.373, P = 0.003), which was consistent with our data showing that STAT3 as the transcriptional factor enhanced EZH2 transcriptional activity by binding the relative promoter region (-214 ~ -206). STAT3 was an independent signature for poor survival (P = 0.002). Patients with STAT3⁺/EZH2⁺ or p-STAT3⁺/EZH2⁺ had a worse outcome than others (P < 0.001); Besides, high levels of STAT3 and EZH2 was associated with advanced TNM staging (P = 0.017). Moreover, treatment with a combination of siSTAT3 and EZH2-specific inhibitor, 3-deazaneplanocin A (DZNEP), increased the apoptotic ratio of cells. It is benefit for targeting STAT3-EZH2 interplay in GC treatment.

CONCLUSIONS

Our results indicate that STAT3 status mediated EZH2 upregulation, associated with advanced TNM stage and poor prognosis, suggesting that combination with knockdown of STAT3 and EZH2 inhibitor might be a novel therapy in GC treatment. Collectively, STAT3, p-STAT3 and EZH2 expression were provided for the precision medicine in GC patients.

Randomized controlled trials evaluating cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in prevention and therapy of peritoneal metastasis: a systematic review

BACKGROUND

Cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is increasingly used to prevent or treat peritoneal metastases (PM) in selected indications. The objective of this article was to review published, recruiting or planned randomized controlled trials (RCTs) evaluating CRS and HIPEC versus standard of care. Comparator was systemic chemotherapy and/or CRS alone.

CONTENT

Systematic review according to PRISMA guidelines. Electronic searches for published RCT using PubMed (from 1980 to November 2016) and for ongoing RCT in the United States and European clinical databases (until November 2016). Current update on ongoing trials from the 10th PSOGI meeting in November 2016 in Washington DC. Fourteen RCTs on CRS and HIPEC were excluded for various reasons.

SUMMARY

Thirty-eight trials designed for randomizing 7,303 patients were identified: 11 in colorectal cancer (6 for prevention of PM, n=1,107 patients; 5 for therapy, n=781), 10 in ovarian cancer (5 in frontline therapy, n=438 patients; 5 for treating recurrence, n=1,062) and 17 in gastric cancer (14 for prevention of PM, n=3,659 patients; 3 for therapy, n=256). Results of 9 RCTs have been published: 1 in colorectal cancer (105 patients), 1 in ovarian cancer (130 patients) and 7 in gastric cancer (together 669 patients). Five RCTs have completed recruitment and follow-up is ongoing. There is a clear trend in recent trial design from therapeutic to preventive indications.

OUTLOOK

The number of published RCT evaluating CRS and HIPEC in prevention or therapy of PM is relatively small. There is some evidence that CRS and HIPEC improve survival in recurrent colorectal origin, evidence in ovarian and gastric cancer remains debated. A large number of studies is ongoing that might deliver additional evidence. Trial design and interpretation of results remain difficult because of multiple methodological challenges.

Human papillomavirus as a potential risk factor for gastric cancer: a meta-analysis of 1,917 cases

Background

Human papillomaviruses (HPVs) are causally associated with the tumorigenesis of several classes of cancers. However, the prevalence of HPV in gastric cancer (GC) has not yet been systematically reviewed. Hence, a meta-analysis was conducted to estimate the HPV prevalence in patients with GC, and its potential etiologic significance was assessed.

Methods

The pooled HPV prevalence and 95% confidence intervals (CIs) were estimated among all GC patients. Heterogeneity was described by using the I² statistic. Sources of heterogeneity were explored by meta-regression and stratified analyses. The meta-influence was applied to evaluate the influence of a single study on the pooled estimates. Odds ratios (ORs) and 95% CIs were computed for case–control studies. For research providing clinicopathological parameters of age, sex, pathological, differentiated, and clinical stages, and HPV subtypes, the corresponding pooled ORs and 95% CIs were also calculated.

Results

Thirty studies were included in the current meta-analysis, involving 1,917 patients with GC and 576 controls. The pooled HPV prevalence was 28.0% (95% CI: 23.2%, 32.7%) among all the patients with GC, and the I² was 96.9% (P<0.001). A pooled OR of 7.388 (95% CI: 3.876, 14.082) was achieved based on 15 case–control studies (I²=56.7%, P=0.004). Moreover, the HPV prevalence was significantly higher in patients from China than in those from non-Chinese regions (31% vs 9%, I²=95.0%, P<0.001). The pooled prevalence of HPV16 was 21% in GC tissues, and the pooled prevalence of HPV18 was 7% with an OR of 3.314 (95% CI =1.617, 6.792). HPV16 was 3 times more frequently detected than HPV18.

Conclusion

HPV could play a potential role in the pathogenesis of GC. A causal relationship can be confirmed only by detecting HPV in the cells of GC precursor lesions (gastric dysplasia or adenoma). In addition, this study might be beneficial for expounding the potential etiologic significance of molecular mechanism of gastric tumorigenesis and providing opinions regarding precautionary measures.

The application of nanoparticles in diagnosis and theranostics of gastric cancer

Gastric cancer is the fourth most common cancer and the second leading cause of cancer related death worldwide. For the diagnosis of gastric cancer, apart from regular systemic imaging, the locoregional imaging is also of great importance. Moreover, there are still other ways for the detecting of gastric cancer, including the early detection of gastric cancer by endoscopy, the detection of gastric-cancer related biomarkers and the detection of circulating tumor cells (CTCs) of gastric cancer. However, conventional diagnostic methods are usually lack of specificity and sensitivity. Nanoparticles provide many benefits in the diagnosis of gastric cancer. Besides, nanoparticles are capable of integrating the functions of diagnosis and treatment together (theranostics). In this paper, we reviewed the applications of nanoparticles in diagnosis and theranostics of gastric cancer in the above mentioned aspects.

DNMT1, DNMT3A and DNMT3B Polymorphisms Associated With Gastric Cancer Risk: A Systematic Review and Meta-analysis

BACKGROUND

Increasing studies showed that abnormal changes in single nucleotide polymorphisms (SNPs) of DNMTs (DNMT1, DNMT3A and DNMT3B) were associated with occurrence or decrease of various tumors. However, the associations between DNMTs variations and gastric cancer (GC) risk were still conflicting. We aimed to assess the effect of DNMTs polymorphisms on the susceptibility to GC.

METHODS

Firstly, we did a meta-analysis for 7 SNPs (rs16999593, rs2228611, rs8101866 in DNMT1, rs1550117, rs13420827 in DNMT3A, rs1569686, rs2424913 in DNMT3B). Four genetic models (homozygote, heterozygote, dominant and recessive model) were used. Moreover, a meta-sensitivity and subgroup analysis was performed to clarify heterogeneity source. Lastly, 17 SNPs that couldn't be meta-analyzed were presented in a systematic review.

FINDINGS

20 studies were included, 13 studies could be meta-analyzed and 7 ones could not. Firstly, a meta-analysis on 13 studies (3959 GC cases and 5992 controls) for 7 SNPs showed that GC risk increased in rs16999593 (heterozygote model: OR 1.36, 95%CI 1.14-1.61; dominant model: OR 1.36, 95%CI 1.15-1.60) and rs1550117 (homozygote model: OR 2.03, 95%CI 1.38-3.00; dominant model: OR 1.20, 95%CI 1.01-1.42; recessive model: OR 1.96, 95%CI 1.33-2.89) but decreased in rs1569686 (dominant model: OR 0.74, 95%CI 0.61-0.90). The remaining SNPs were not found associated with GC risk. Furthermore, the subgroup analysis indicated that for rs1550117 and rs1569686, the significant associations were particularly found in people from Chinese Jiangsu province (rs1550117, OR 1.77, 95%CI 1.25-2.51; rs1569686, OR 0.48, 95%CI 0.36-0.64) and that PCR-RFLP was a sensitive method to discover significant associations (rs1550117, OR 1.77, 95%CI 1.25-2.51; rs1569686, OR 0.49, 95%CI 0.37-0.65). Lastly, a systematic review on 7 studies for 17 SNPs suggested that rs36012910, rs7560488 and rs6087990 might have a potential effect on GC initiation.

CONCLUSION

This meta-analysis demonstrated that rs16999593 and rs1550117 could contribute to GC risk and that rs1569686 might be a protective factor against gastric carcinogenesis. By using these SNPs as biomarkers, it is feasible to estimate the risk of acquiring GC and thus formulate timely preventive strategy.

Downregulation of Potential Tumor Suppressor miR-203a by Promoter Methylation Contributes to the Invasiveness of Gastric Cardia Adenocarcinoma

Like many tumor suppressor genes, some miRNA genes harboring CpG islands undergo methylation-mediated silencing. In the study, we found significant downregulation and proximal promoter methylation of miR-203a and miR-203b in gastric cardia adenocarcinoma (GCA) tissues. The methylation status of miR-203a and miR-203b in tumor tissues was negatively correlated with their expression level. GCA patients in stage III and IV with reduced expression or hypermethylation of miR-203a demonstrated poor patient survival. In all, miR-203a and miR-203b may function as tumor suppressive miRNAs, and reactivation of miR-203a may have therapeutic potential and may be used as prognostic marker for GCA patients.

MicroRNA-1225-5p inhibits proliferation and metastasis of gastric carcinoma through repressing insulin receptor substrate-1 and activation of β-catenin signaling

Emerging evidence has linked aberrantly expressed microRNAs (miRNAs) with oncogenesis and malignant development in various human cancers. However, their specific roles and functions in gastric carcinoma (GC) remain largely undefined. In this study we identify and report a novel miRNA, miR-1225-5p, as tumor suppressor in GC development and progression. Microarray analysis revealed that there were fifty-six differentially expressed miRNAs (thirty-two upregulated and twenty-four downregulated) in GC tumor samples compared to their corresponding nontumorous tissues. Downregulation of miR-1225-5p was frequently detected in GC and strongly correlated with more aggressive phenotypes and poor prognosis. Functional assays demonstrated that ectopic overexpression of miR-1225-5p could inhibit cell proliferation, colony formation, migration and invasion in vitro, as well as suppress tumor growth and metastasis in nude mice. Further integrative and functional studies suggested insulin receptor substrate 1 (IRS1) as a downstream effector of miR-1225-5p which acted through β-catenin signaling pathway. These results demonstrate that miR-1225-5p serves to constrain GC growth and metastatic potential via inhibition of IRS1 and β-catenin signaling. Therefore, downregulation of miR-1225-5p is likely to be one of major molecular mechanisms accounting for the development and progression of GC.

MicroRNA-200c is involved in proliferation of gastric cancer by directly repressing p27Kip1

P27^Kip1, also known as Cyclin-dependent kinase inhibitor 1B, is an important check-point protein in the cell cycle. It has been identified that although as a tumor suppressor, P27^Kip1 is expressed in different cancer cell types, which shows the therapeutic potential in tumor genesis. In this study, we examined the upstream regulatory mechanism of P27^Kip1 at the microRNA (miRNA) level in gastric carcinogenesis. We used bioinformatics to predict that microRNA-200c (miR-200c) might be a direct upstream regulator of P27^Kip1. It was also verified in gastric epithelial-derived cell lines that overexpression of miR-200c significantly inhibited the expression levels of P27^Kip1, whereas knockdown of miR-200c promoted P27^Kip1 expression in AGS and BGC-823 cells. Furthermore, we identified the direct binding of miR-200c on the P27^Kip1 3′ -UTR sequence by luciferase assay. MiR-200c could enhance the colony formation of cells by repressing P27^Kip1 expression. In addition, the negative correlation between P27^Kip1 and miR-200c in human gastric cancer tissues and matched normal tissues further supported the tumor-promoting action of miR-200c in vivo. Our finding suggested that miR-200c directly regulates the expression of P27^Kip1 and promotes cell growth in gastric cancer as an oncogene, which may provide new clues to treatment.

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miR-200c is involved in the proliferation of gastric cancer cell lines.

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P27Kip1 is a direct downstream target of miR-200c.

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miR-200c is determined an oncogene in human gastric cancer tissue species.

miR-218 Inhibits Proliferation, Migration, and EMT of Gastric Cancer Cells by Targeting WASF3

MicroRNAs (miRNAs) play an important role in carcinogenesis. miR-218 is one of the most known miRNAs and has been demonstrated to inhibit progression in gastric cancer. However, the underlying molecular mechanism is not established. In this study, qRT-PCR and Western blot indicated that miR-218 was downregulated in gastric cancer cell lines SGC7901 and BGC823 compared to that in normal gastric epithelial cell line GES-1. MTT and wound scratch assays suggested that overexpression of miR-218 markedly suppressed cell proliferation, migration, and EMT of gastric cancer cells. Furthermore, we proved that WASF3 was a direct target of miR-218 by luciferase reporter assay, and restoration of WASF3 expression impairs miR-218-induced inhibition of proliferation, migration, and EMT in gastric cancer cells SGC7901. In summary, our results demonstrated that miR-218 functions as one of the tumor-suppressive miRNAs and inhibits gastric cancer tumorigenesis by targeting WASF3. miR-218 may serve as a potential therapeutic target for the treatment of gastric cancer.

MicroRNA-561 inhibits gastric cancercell proliferation and invasion by downregulating c-Myc expression

Gastric cancer (GC) causes nearly one million deaths worldwide each year. However, the molecular pathway of GC development remains unclear. Increasing evidences have shown that microRNAs (miRNAs) are highly associated with tumor development. However, relative little is known about the potential role of miRNAs in gastric cancer development. In the present study, we showed that miR-561 was down-regulated frequently in human GCs cell lines and tissues, and its expression was associated with tumor-node-metastasis (pTNM) stage. Enforced expression of miR-561 in GC cells inhibited cell proliferation and invasion in vitro. In contrast, knockdown of miR-561 had the opposite effect on cell proliferation and invasion. Moreover, c-Myc was identified as a potential miR-561 target. Further studies confirmed that miR-561 suppressed the expression of c-Myc by directly binding to its 3'-untranslated region. Restoration of c-Myc in miR-561-overexpressed GC cells reversed the suppressive effects of miR-561 and c-Myc was inversely correlated with miR-561 expression in GC tissues. These results demonstrate that miR-561 acts as a novel tumor suppressor in GC by targeting c-Myc gene and inhibiting GC cells proliferation and invasion. These findings contribute to current understanding of the functions of miR-561 in GC.

Tbx3 overexpression in human gastric cancer is correlated with advanced tumor stage and nodal status and promotes cancer cell growth and invasion

The objective of the current study was to investigate the expression pattern of Tbx3 and its clinicopathological significance in patients with gastric cancer. The expression pattern of Tbx3 in gastric cancer tissues and adjacent noncancerous surface epithelia and mucosal glands was detected by immunohistochemistry. Tbx3 was found to be overexpressed in 46 of 98 human gastric cancer samples, and this correlated with advanced clinical stage, tumor stage, and nodal status. In addition, in the SGC-7901 gastric cancer cell line, Tbx3 overexpression by plasmid transfection promoted growth and invasion. Conversely, depleting Tbx3 expression by small-interfering RNA inhibited proliferation and invasion in BGC-823 cell line. Moreover, Tbx3 accelerated cell cycle progression at the G1/S boundary. Tbx3 also regulated epithelial-to-mesenchymal transition (EMT) to promote cell invasion by repressing E-cadherin expression and increasing expression levels N-cadherin, vimentin. These results indicate that in gastric cancer, Tbx3 plays an important role and might be a useful therapy target.

Alu-based cell-free DNA: a novel biomarker for screening of gastric cancer

Gastric cancer (GC) is the fourth most common cancer and the second major cause of cancer-related deaths worldwide. In our previous study, a novel and sensitive method for quantifying cell-free DNA (CFD) in human blood was established and tested for its ability to predict patients with tumor. We want to investigate CFD expression in the sera of GC patients in an attempt to explore the clinical significance of CFD in improving the early screening of GC and monitoring GC progression by the branched DNA (bDNA)-based Alu assay. The concentration of CFD was quantitated by bDNA-based Alu assay. CEA, CA19-9, C72-4 and CA50 concentrations were determined by ABBOTT ARCHITECT I2000 SR. We found the CFD concentrations have significant differences between GC patients, benign gastric disease (BGD) patients and healthy controls (P < 0.05). CFD were weakly correlated with CEA (r = −0.197, P < 0.05) or CA50 (r = 0.206, P < 0.05), and no correlation with CA19-9 (r = −0.061, P > 0.05) or CA72-4 (r = 0.011, P > 0.05). In addition, CFD concentrations were significantly higher in stage I GC patients than BGD patients and healthy controls (P < 0.05), but there was no significant difference in CEA, CA19-9 and CA50 among the three traditional tumor markers (P > 0.05). Our analysis showed that CFD was more sensitive than CEA, CA19-9, CA72-4 or CA50 in early screening of GC. Compared with CEA, CA19-9, CA72-4 and CA50, CFD may prove to be a better biomarker for the screening of GC, thus providing a sensitive biomarker for screening and monitoring progression of GC.

miR-302b regulates cell cycles by targeting CDK2 via ERK signaling pathway in gastric cancer

To investigate the molecular mechanism of miR‐302b in the regulation of cell proliferation and cell cycle regulation in gastric cancer. Samples of tumor and adjacent normal tissues were collected from 30 gastric cancer patients. Bioinformatics and the dual luciferase report were used for verification of the relationship between miR‐302b expression and cyclin‐dependent kinase 2 (CDK2). RT‐PCR and western blot were used to examine CDK2 mRNA and protein levels. The impacts of miR‐302b on CDK2 expression and extracellular signal‐regulated kinase (ERK) signaling pathway were assessed in cells transfected with miR‐302b analogs and CDK2 overexpression carrier, respectively. We used 3‐(4,5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide (MTT) to assay gastric cancer cell growth after transfection, flow cytometry to analyze cell cycle. Compared with normal tissues, miR‐302b expression was significantly lower in gastric cancer tissues, which was significantly related to lymph node metastasis, metastasis distance, and TNM staging. miR‐302b expression was increased in miR‐302b mimics transfected cells and was significantly decreased in miR‐302b inhibitors transfected cells. CDK2 is a target gene of miR‐302b. Decreased miR‐302b and increased CDK2 expressions can significantly promote proliferation and G1/S phase transformation in gastric cancer. miR‐302b promoted the proliferation of gastric cancer cells through upregulation of CDK2, thereby inhibiting ERK pathway, which can in turn inhibit the promoting ability of miR‐302b on proliferation. The upregulation of miR‐302b reduced the expression of CDK2, and inhibited ERK signaling pathway, thereby inhibiting cell proliferation and G1/S phase conversion rate. Therefore, miR‐302b provides new perspectives for research of cell regulation and proliferation in gastric cancer, and new targets for gastric cancer diagnosis and treatment.

Galectin-8 is associated with recurrence and survival of patients with non-metastatic gastric cancer after surgery

The expression of galectin family has been unraveled in many malignant tumors and related with clinical outcomes. Our current study aims to investigate the prognostic value of galectin-8 expression and refine the current risk stratification system in non-metastatic gastric cancer patients. We retrospectively enrolled 421 patients with gastric cancer from Zhongshan Hospital, Fudan University in 2008. The expression of galectin-8 was detected by immunohistochemistry, and its association with clinicopathological features and prognostic outcomes were assessed. We found that galectin-8 expression was significantly associated with tumor size (P = 0.007), T stage (P = 0.001), N stage (P < 0.001), and tumor node metastasis (TNM) stage (P < 0.001). In addition, low galectin-8 expression indicated poor overall survival (OS) (P < 0.001) and disease-free survival (DFS) (P < 0.001). Furthermore, galectin-8 expression level was identified as an independent favorable prognostic factor for OS (P < 0.001). A predictive nomogram was generated with identified independent prognosticators to evaluate patient OS at 3 and 5 years. Our study suggested that galectin-8 is a potential independent favorable prognostic biomarker for survival and recurrence of patients with gastric cancer after surgical resection and the integration of intratumoral galectin-8 expression level into current TNM staging system would help to refine individual risk stratification.

Intervention effect of pinelliae decoction for purging stomach-fire on malignant transformation of bone marrow mesenchymal stem cells in the gastric cancer microenvironment

OBJECTIVE

The study aimed to simulate the microenvironment of gastric cancer to promote the malignant transformation of bone marrow mesenchymal stem cells (BMSCs) and further evaluate the effect of Pinelliae Decoction for Purging Stomach-Fire and its disassembled prescriptions on BMSCs.

METHODS

Transwell co-culture was performed on the human gastric cancer cell strains BGC-823 and BMSCs to simulate the microenvironment of gastric cancer. The drug-containing serum prepared by Pinelliae Decoction for Purging Stomach-Fire and its disassembled prescriptions was used, and its influence on BMSCs with malignant transformation was observed.

RESULTS

BMSCs were harvested successfully from the rat bone marrow, and flow cytometer identification indicated that CD44+/CD34- cells accounted for 70.64%. The co-culture of BGC-823 cells can induce malignant transformation of BMSCs. And the drug-containing serum can induce G2 phase arrest, inhibit cell proliferation, simultaneously inhibit TERT and c-myc expression, lower the cellular ability of chemotactic migration, inhibit the tumor-forming ability of BGC-823 in nude rats and promote the tumor apoptosis.

CONCLUSION

The effective components of Pinelliae Decoction for Purging Stomach-Fire in gastric cancer treatment are pinelliae and dried ginger, and the main acting mechanism is to inhibit tumor cell proliferation and chemotactic migration and promote apoptosis.

Low Expression of CDK5 and p27 Are Associated with Poor Prognosis in Patients with Gastric Cancer

Several previous studies have demonstrated that CDK5 or p27 expression in gastric cancer are associated with overall survival. We have previously reported that tumor suppressive function of CDK5 is related to p27. The aim of this study was to investigate correlation between the clinicopathological parameters and overall survival with different CDK5/p27 expression statuses in 244 gastric cancer patients using immunohistochemistry. Low CDK5 expression was detected in 93 cases (38.11%) and low p27 in 157 cases (64.34%). The expression of CDK5 was significantly related to sex (P = 0.034) and Lauren's classification (P = 0.013). The expression of p27 was significantly related to sex (P = 0.012), differentiation (P = 0.003), TNM stage (P = 0.013) and lymph node metastasis (P = 0.001). Based on the combined expression of CDK5 and p27, we classified the patients into four subtypes: CDK5 Low/p27 Low (n = 69), CDK5 High/p27 Low (n = 88), CDK5 Low/p27 High (n = 24) and CDK5 High/p27 High (n = 63). The CDK5 Low/p27 Low expression was closely related to female (P = 0.026), diffuse type (P = 0.027) and lymph node metastasis (P = 0.010). The CDK5 Low/p27 Low patients displayed poorer survival in comparison with the rest of the patients in Kaplan-Meier analysis. No significant overall survival difference was observed among the patients with CDK5 High and/or p27 High expression. In the multivariate analysis, CDK5 and p27 co-expression status was identified as an independent prognostic factor for patients with gastric cancer.

Correlation Between Interleukin-1β-511 C/T Polymorphism and Gastric Cancer in Chinese Populations: A Meta-Analysis

Background

Several studies have indicated that interleukin (IL)-1β-511 C/T polymorphism may contribute to individual susceptibility to gastric cancer, but the results vary among regions and races. No relevant meta-analysis has been conducted in a Chinese population. Therefore, we performed the current meta-analysis to investigate the possible correlation between IL-1β-511 C/T polymorphism and gastric cancer susceptibility in Chinese subjects.

Material/Methods

PubMed, EmBase, Cochrane Library, Chinese Biology Medicine (CBM), Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases were searched for case-control studies published before 21 January 2015 and investigating a correlation between IL-1β-511 C/T polymorphism and gastric cancer susceptibility. Two investigators independently screened the studies, extracted data, and evaluated the quality of included studies with the Newcastle-Ottawa scale. Meta-analysis was conducted with STATA 12.0.

Results

A total of 27 articles from 28 case-control studies were collected. Meta-analysis showed that IL-1β-511C/T polymorphism was related to increased susceptibility to gastric cancer in Chinese subjects [T vs. C: OR=1.21, 95%CI (1.07–1.37), P<0.01; TT vs. CC: OR=1.41, 95%CI (1.11–1.80), P<0.01; CT vs. CC: OR=1.26, 95% CI (1.05–1.50), P<0.01; TT+CT vs. CC: OR=1.31, 95%CI (1.08–1.58), P<0.01; and TT vs. CT+CC: OR=1.24, 95%CI (1.05–1.47), P<0.01]. Subgroup analysis showed a significant correlation between IL-1β-511C/T polymorphism and susceptibility to gastric cancer in residents of southern China and in patients with intestinal-type gastric cancer, but not in residents of northern China or in patients with diffuse gastric cancer. Moreover, H. pylori-infected subjects carrying T (CT+TT) exhibited a relatively higher risk of GC [OR=2.4, 95% CI (1.2–5.1), P=0.02].

Conclusions

IL-1β-511C/T polymorphism is significantly associated with increased susceptibility to gastric cancer in residents of southern China and in intestinal-type gastric cancer. We also found a synergistic interaction between IL-1β-511C/T polymorphism and H. pylori infection in the development of GC.

Long noncoding RNA OR3A4 promotes metastasis and tumorigenicity in gastric cancer

The contribution of long noncoding RNAs (lncRNAs) to metastasis of gastric cancer remains largely unknown. We used microarray analysis to identify lncRNAs differentially expressed between normal gastric tissues and gastric cancer tissues and validated these differences in quantitative real-time (qRT)-PCR experiments. The expression levels of lncRNA olfactory receptor, family 3, subfamily A, member 4 (OR3A4) were significantly associated with lymphatic metastasis, the depth of cancer invasion, and distal metastasis in 130 paired gastric cancer tissues. The effects of OR3A4 were assessed by overexpressing and silencing OR3A4 in gastric cancer cells. OR3A4 promoted cancer cell growth, angiogenesis, metastasis, and tumorigenesis in vitro and in vivo. Global microarray analysis combined with RT-PCR, RNA immunoprecipitation, and RNA pull-down analyses after OR3A4 transfection demonstrated that OR3A4 influenced biologic functions in gastric cancer cells via regulating the activation of PDLIM2, MACC1, NTN4, and GNB2L1. Our results reveal OR3A4 as an oncogenic lncRNA that promotes tumor progression, Therefore, lncRNAs might function as key regulatory hubs in gastric cancer progression.

By downregulating TIAM1 expression, microRNA-329 suppresses gastric cancer invasion and growth

Gastric cancer (GC) is one of the most common malignant tumors worldwide. Emerging evidence has shown that abnormal microRNAs (miRNAs) expression is involved in tumorigenesis. MiR-329 was previously reported to act as a tumor suppressor or oncogene in some types of cancer. However, its function in gastric cancer (GC) is unclear. Here, we found that miR-329 was down-regulated in GC compared with adjacent controls. Enforced expression of miR-329 inhibited proliferation, migration and invasion of gastric cancer cells in vitro. We identified T lymphoma invasion and metastasis 1 (TIAM1) gene as potential target of miR-329. MiR-329 levels inversely correlated with TIAM1 expression in GC. Importantly, TIAM1 rescued the miR-329-mediated inhibition of cell invasion and proliferation. Finally, reintroduction of miR-329 significantly inhibited tumor formation of GC in the xenograft mice. Our findings suggest that miR-329 is a tumor suppressor and potential therapeutic target of GC

Methylation-mediated downregulation of long noncoding RNA LOC100130476 in gastric cardia adenocarcinoma

Accumulating evidences indicate that long non-coding RNAs (lncRNAs) play important roles in several biological processes and dysregulated lncRNAs are involved in different kinds of cancer and are associated with carcinogenesis, metastasis, and prognosis of cancer. The role of a new lncRNA LOC100130476 in gastric cardia adenocarcinoma (GCA) has remained unknown. The present study investigated the role and methylation status of LOC100130476 in the pathogenesis of GCA, and further evaluated the potential prognostic role of LOC100130476 in GCA. Significant downregulation of LOC100130476 was detected in SGC-7901 and BGC-823 cell lines and primary GCA tissues. Methylation frequency of LOC100130476 was gradually increased from exon 1 to exon 2 both in tumor tissues and corresponding normal tissues; however, methylation status of region 1 closing to the transcription start site was more tumor-specific among the three regions examined. The findings of the association between LOC100130476 expression, methylation and TNM stage, pathological differentiation, and GCA patients' survival further identified the role of LOC100130476 as a tumor suppressor gene. Furthermore, the hypermethylation of LOC100130476 was also detected in peripheral white blood cells of GCA cases. Thus, LOC100130476 may be act as a tumor suppressor gene in GCA carcinogenesis and aberrant methylation at the CpG sites near the transcription start site within exon 1 may be critical for gene silencing. In addition, aberrant methylation of LOC100130476 in peripheral white blood cells and GCA tissues may be used as a potential valuable biomarker in GCA diagnosis and prognosis.

FEATURES

Fighting Cancer with Immunotherapy.

21st Century Cancer Warfare: A Glimpse into the Operations of a Modern Radiotherapy Unit.

Is Colorectal Carcinomas due to ‘Bad Luck’ or Is It Preventable?

Asian Point of View on Cancer.

Improving Overall Survival in Hepatocellular Carcinoma through a Multi-Disciplinary Approach: Intra-Tumoral Heterogeneity, Immunology and the Promise of Better Outcomes.

Cancer of the Cervix – Can It be Prevented?

Prognostic Significance of MiR-34a Expression in Patients with Gastric Cancer after Radical Gastrectomy

BACKGROUND

MiR-34a dysregulation has been implicated in tumorigenesis and progression of gastric cancer, but its role in prognosis of patients with gastric cancer remains unknown. The aim of this study was to investigate the expression and prognostic significance of miR-34a in gastric cancer patients after radical gastrectomy.

METHODS

Quantitative real-time polymerase chain reaction was performed to detect the expression of miR-34a in human gastric cancer cell lines and tissues in 76 patients with gastric adenocarcinoma from China. Results are assessed for association with clinical features and overall survival (OS) using Kaplan-Meier analysis. Prognostic values of miR-34a expression and clinical outcomes were evaluated by Cox regression analysis. A molecular prognostic stratification scheme incorporating miR-34a expression was determined using receiver operating characteristic analysis.

RESULTS

The results show that the expression level of miR-34a was decreased in human gastric cancer cell lines and tissues, and down-regulated expression of miR-34a was associated with Lauren classification (P = 0.034). Decreased miR-34a expression in gastric cancer tissues was positively correlated with poor OS of gastric cancer patients (P = 0.013). Further multivariate Cox regression analysis suggested that miR-34a expression was an independent prognostic indicator for gastric cancer (P = 0.027). Applying the prognostic value of miR-34a expression to tumor node metastasis (TNM) stage system showed a better prognostic value in patients with gastric cancer than miR-34a expression (P = 0.0435) or TNM stage (P = 0.0249) alone.

CONCLUSION

The results reinforce the critical role for the down-regulated miR-34a expression in gastric cancer and suggest that miR-34a could be a prognostic indicator for this disease.

Association study between genome-wide significant variants of vitamin B12 metabolism and gastric cancer in a han Chinese population

Gastric cancer is one of the leading causes of cancer mortality worldwide. Accumulating evidence suggests that vitamin B12 plays an important role in the development of gastric cancer. Genome-wide association studies on metabolites in the one-carbon metabolism pathway identified several vitamin B12-related polymorphisms. Therefore, we investigated the association between variants within vitamin B12-related genes and gastric cancer in a Han Chinese population. Eight variants within the genome were significant vitamin B12-related genes, and they were selected for analysis in this case-control study. This study used a total of 492 gastric cancer patients and 550 noncancer controls. The variant rs526934 from the TCN1 gene was associated with an increased risk of developing gastric cancer. Increased risks of gastric cancer occurrence were observed in the minor G allele (OR = 1.25, 95% CI = 1.03-1.52, P = 0.031) and GG genotype (OR = 2.06, 95% CI = 1.24-3.42, P = 0.0043) compared with the wild-type A allele and AA-GA genotype, respectively. In the haplotypic analysis, we found that the CUBN haplotypes were associated with an altered gastric cancer risk. The rs1801222T/rs11254363A (OR = 1.40, 95% CI = 1.05-1.86, P = 0.021) and rs1801222C/rs11254363G (OR = 4.39, 95% CI = 2.32-8.30, P < 0.0001) haplotypes exhibited an increased gastric cancer risk, while rs1801222T/rs11254363G showed protective effects against gastric cancer (OR = 0.43, 95% CI = 0.25-0.73, P = 0.002) compared with the wild-type rs1801222C/rs11254363A haplotype. The circulating vitamin B12 concentration-related variants were associated with the occurrence of gastric cancer. This finding shed light on the unexpected role of vitamin B12 metabolism genes in gastric carcinogenesis and highlighted the interplay of diet, genetics, and human cancers.