Progression Of Gastric Adenocarcinoma Research Articles

Metabolic Reprogramming in Response to Alterations of Mitochondrial DNA and Mitochondrial Dysfunction in Gastric Adenocarcinoma

We used gastric cancer cell line AGS and clinical samples to investigate the roles of mitochondrial DNA (mtDNA) alterations and mitochondrial respiratory dysfunction in gastric adenocarcinoma (GAC). A total of 131 clinical samples, including 17 normal gastric mucosa (N-GM) from overweight patients who had received sleeve gastrectomy and 57 paired non-cancerous gastric mucosae (NC-GM) and GAC from GAC patients who had undergone partial/subtotal/total gastrectomy, were recruited to examine the copy number and D310 sequences of mtDNA. The gastric cancer cell line AGS was used with knockdown (KD) mitochondrial transcription factor A (TFAM) to achieve mitochondrial dysfunction through a decrease of mtDNA copy number. Parental (PT), null-target (NT), and TFAM-KD-(A/B/C) represented the parental, control, and TFAM knocked-down AGS cells, respectively. These cells were used to compare the parameters reflecting mitochondrial biogenesis, glycolysis, and cell migration activity. The median mtDNA copy numbers of 17 N-GM, 57 NC-GM, and 57 GAC were 0.058, 0.055, and 0.045, respectively. The trend of decrease was significant (p = 0.030). In addition, GAC had a lower mean mtDNA copy number of 0.055 as compared with the paired NC-GM of 0.078 (p < 0.001). The mean mtDNA copy number ratio (mtDNA copy number of GAC/mtDNA copy number of paired NC-GM) was 0.891. A total of 35 (61.4%) GAC samples had an mtDNA copy number ratio ≤0.804 (p = 0.017) and 27 (47.4%) harbored a D310 mutation (p = 0.047), and these patients had shorter survival time and poorer prognosis. After effective knockdown of TFAM, TFAM-KD-B/C cells expressed higher levels of hexokinase II (HK-II) and v-akt murine thymoma viral oncogene homolog 1 gene (AKT)-encoded AKT, but lower levels of phosphorylated pyruvate dehydrogenase (p-PDH) than did the NT/PT AGS cells. Except for a higher level of p-PDH, the expression levels of these proteins remained unchanged in TFAM-KD-A, which had a mild knockdown of TFAM. Compared to those of NT, TFAM-KD-C had not only a lower mtDNA copy number (p = 0.050), but also lower oxygen consumption rates (OCR), including basal respiration (OCRBR), ATP-coupled respiration (OCRATP), reserve capacity (OCRRC), and proton leak (OCRPL)(all with p = 0.050). In contrast, TFAM-KD-C expressed a higher extracellular acidification rate (ECAR)/OCRBR ratio (p = 0.050) and a faster wound healing migration at 6, 12, and 18 h, respectively (all with p = 0.050). Beyond a threshold, the decrease in mtDNA copy number, the mtDNA D310 mutation, and mitochondrial dysfunction were involved in the carcinogenesis and progression of GACs. Activation of PDH might be considered as compensation for the mitochondrial dysfunction in response to glucose metabolic reprogramming or to adjust mitochondrial plasticity in GAC.

An integrated analysis of DNA promoter methylation, microRNA regulation, and gene expression in gastric adenocarcinoma.

BackgroundGastric adenocarcinoma (GAC), a common type of gastric cancer, poses a significant public health threat worldwide. This study aimed to determine the transcriptional regulatory mechanisms of GAC.MethodsHTSeq-FPKM raw data were obtained from The Cancer Genome Atlas Stomach Adenocarcinoma data collection. Subsequently, the limma package in R was used to identify differentially expressed genes (DEGs). Differentially methylated genes (DMGs), DEGs, and differentially expressed microRNAs (miRNAs) in normal, and tumor tissues of the same patients were screened and compared using R software tools. A functional enrichment analysis was performed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) for various DEGs, DMGs, promoter methylation, and miRNAs. DEG-specific methylation and transcription factors were analyzed using ENCODE ChIP-seq.ResultsDEGs were centrally modified by the histone trimethylation of lysine 27 on histone H3 (H3K27me3). Upstream transcription factors of DEGs were enriched in different ChIP-seq clusters, such as Forkhead Box M1, E2F Transcription Factor 4, and suppressor of zest 12. Integrated regulatory networks of DEGs, promoter methylation, and miRNAs were constructed. Two miRNAs (hsa-mir-1 and hsa-mir-133a) and four DEGs (A disintegrin and metalloproteinase domain 12, transcription factor AP-2 alpha, solute carrier family 5 member 7, and cadherin 19) separately played important roles in the integrated regulatory network. Therefore, these DEGs, DMGs, promoter methylation, and miRNAs may play an important role in GAC pathogenesis.ConclusionsIn summary, the present study results provide insights into the oncogenesis and progression of GAC, thus accelerating the development of novel targeted GAC therapies.

Diagnostic and therapeutic potencies of miR-18a-5p in mixed-type gastric adenocarcinoma.

Mixed‐type gastric adenocarcinoma (by Lauren Classification) has poor clinical outcomes with few targeted treatment options. The primary objective of this study was to find the prognostic factors, accurate treatment approaches, and effective postoperative adjuvant therapy strategies for patients with mixed‐type gastric adenocarcinoma (GA). A microRNA sequencing data set and the corresponding clinical parameters of patients with gastric cancer were obtained from The Cancer Genome Atlas. Differentially expressed microRNAs (DEMs) of diffuse‐ and intestinal‐type GA were, respectively, determined. Kaplan–Meier and log‐rank tests were subsequently carried out to evaluate the prognostic relevance of each DEM. To study the common factors between diffuse‐ and intestinal‐type GA, a pathway enrichment analysis was performed on the target genes of identified DEMs using the PANTHER database. After data preprocessing, we analyzed a total of 230 samples from 210 patients with GA. Eighty‐six DEMs in diffuse‐type GA samples and 59 DEMs in intestinal‐type GA samples were, respectively, identified (p 2.0). The Kaplan–Meier survival method further screened out six prognosis‐related DEMs for diffuse‐type GA and seven prognosis‐related DEMs for intestinal‐type GA (p < 0.05). MiR‐18a‐5p was found to be the only common prognosis‐related DEM between diffuse‐ and intestinal‐type GA. The common signaling pathways further revealed that target genes of miR‐18a‐5p are involved in mixed‐type GA progression. This study suggests that miR‐18a‐5p acts as a potential target for treatment, and common signal pathways provide a rich basis to seek reliable and effective molecular targets for the diagnosis, clinical treatment, and postoperative adjuvant therapy strategy of mixed‐type GA.

MiRNA-621 exerts tumor suppressor function in gastric adenocarcinoma by targeting AURKA/GSK-3β pathway.

Gastric adenocarcinoma is a major challenge to human health worldwide. Abnormal expression of miR-621 was found in many types of cancer. This research aimed to investigate the effects and detailed molecular mechanisms of miR-621 on gastric adenocarcinoma progression. The present study first showed that miR-621 was downregulated in gastric cancer patients, and its expression level was correlated with tumor size. MiR-621 overexpression inhibited viability, colony formation and proliferation of gastric cancer cells. AURKA was identified as a direct target of miR-621. AURKA knockdown induced decrease of p-GSK-3β/GSK-3β ratio and increase of p-β-catenin/β-catenin ratio which confirmed that AURKA positively regulated GSK-3β phosphorylation. AURKA knockdown also inhibited proliferation of gastric adenocarcinoma cells. AURKA expression was negatively correlated with miR-621 level. In addition, AURKA overexpression reversed the effect of miR-621 on the growth of cancer cells. Taken together, our results suggest that miR-621 is an important tumor suppressor in gastric cancer and could be a promising target for the cancer treatment.

Association of Foxp3 rs3761548 polymorphism with cytokines concentration in gastric adenocarcinoma patients

T regulatory cells (Tregs) and related-cytokines are effectively engaged in the process of tumor immune escape and functionally inhibit immune response against the tumor. This study aimed to investigate the association of Foxp3 gene single nucleotide polymorphism (SNP) (rs3761548) with serum IL-35, IL-10, and TGF-β levels in gastric adenocarcinoma (GA) patients. The blood samples were obtained from 150 GA patients and 166 control subjects. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was done to genotyping of Foxp3 gene polymorphism (rs3761548). The serum cytokines levels were measured using the ELISA method. According to genotyping, the AA, and AC genotypes and A allele demonstrated significantly greater risk of GA. Considering the Lauren classification, our results revealed a greater risk of GA progression in patients with AC + AA genotype compared to CC genotype. Moreover, significantly increased levels of IL-10, IL-35, and TGF-β were observed in GA patients compared to controls and also in diffuse-type compared to the intestinal type of GA patients. The IL-35, IL-10 concentrations in GA patients displayed significant differences between the participants with CC, AC and AA genotypes. Further analysis indicated the prognostic role of serum IL-35, IL-10, and TGF-β levels in GA patients. Our results confirmed that the Foxp3 polymorphism (rs3761548) could influence the predisposition to GA and the serum IL-10, IL-35, and TGF-β levels. Thus, this polymorphism might be involved in the GA progression through influencing Tregs function and the secretion of immunomodulatory cytokines.

LETM1 is a potential biomarker that predicts poor prognosis in gastric adenocarcinoma

Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is closely linked to the occurrence and development of many malignant tumors. Many studies have reported that enhanced expression of LETM1 in several types of human cancers was associated with poor clinical outcomes; however, its clinical significance in gastric adenocarcinoma (GA) has not been elucidated. In this study, we assessed the expression of LETM1 along with the genes related to cancer stemness, cell cycle, and PI3K/Akt signaling in 189 paraffin-embedded GA tissue samples and GA-derived cell lines using immunohistochemistry (IHC), western blotting, and immunofluorescence. Our results showed that the expression of LETM1 was strongly correlated with the tumor grade, primary tumor (pT) stage, lymph node metastasis, clinical stage, and tumor gross type of GA. The Kaplan-Meier survival analysis revealed that patients with GA with high expression of LETM1 exhibit a shorter overall survival (OS) rate. Univariate and multivariate Cox regression analysis indicated that LETM1 is an independent poor prognostic factor of GA. Significantly, LETM1 expression was positively correlated with the expression of cancer stemness-related genes such as CD44 and LGR5 and expression of cell-cycle related gene, cyclin D1. Further, the expression of proteins involved in PI3K/Akt signaling pathway, such as pPI3K-p85 and pAkt-Thr308, was also increased. Additionally, small interfering RNA (esiRNA)-mediated silencing of LETM1 expression in GA-derived cell lines MKN28 and MKN74 strongly inhibited the expression of stemness and cell cycle-related proteins, suppressed cancer cell spheroid formation, migration and invasion ability, and affected cell cycle distribution. Furthermore, the GA-derived cell line AGS exhibited enhanced expression of LETM1, CD44, LGR5, and HIF1-α under hypoxic conditions. Lastly, we blocked PI3K expression using an inhibitor LY294002, which downregulated the expression of LETM1, pPI3K-p85, and pAkt-Thr308. Taken together, our results demonstrate that LETM1 regulates cell proliferation and promotes tumorigenicity of GA, and its overexpression is associated with the poor progression of GA. Therefore, LETM1 could serve as a potential prognostic biomarker and a therapeutic target for the better clinical management of GA.

FN1, SPARC, and SERPINE1 are highly expressed and significantly related to a poor prognosis of gastric adenocarcinoma revealed by microarray and bioinformatics

Gastric adenocarcinoma (GAC), also known as stomach adenocarcinoma (STAD), is one of the most lethal malignancies in the world. It is vital to classify and detect the hub genes and key pathways participated in the initiation and progression of GAC. In this study, we collected and sequenced 15 pairs of GAC tumor tissues and the adjacent normal tissues. Differentially expressed genes (DEGs) were analyzed and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) analysis were used to annotate the unique biological significance and important pathways of enriched DEGs. Moreover, we constructed the protein-protein interaction (PPI) network by Cytoscape and conducted KEGG enrichment analysis of the prime module. We further applied the TCGA database to start the survival analysis of these hub genes by Kaplan-Meier estimates. Finally, we obtained total 233 DEGs consisted of 64 up-regulated genes and 169 down-regulated genes. GO enrichment analysis found that DEGs most significantly enriched in single organism process, extracellular region, and extracellular region part. KEGG pathway enrichment analysis suggested that DEGs most significantly enriched in Protein digestion and absorption, Gastric acid secretion, and ECM-receptor interaction. Furthermore, the PPI network showed that the top 10 hub genes in GAC were IL8, COL1A1, MMP9, SST, COL1A2, TIMP1, FN1, SPARC, ALDH1A1, and SERPINE1 respectively. The prime gene interaction module in PPI network was enriched in protein digestion and absorption, ECM receptor interaction, the PI3K-Akt signaling pathway, and pathway in cancer. Survival analysis based on the TCGA database found that the expression of the FN1, SERPINE1, and SPARC significantly predicted poor prognosis of GAC. Collectively, we identified several hub genes and key pathways associated with GAC initiation and progression by analyzing the microarray data on DEGs, which provided a detailed molecular mechanism underlying GAC occurrence and progression.

Transcriptome sequencing identifies key pathways and genes involved in gastric adenocarcinoma.

The present study aimed to investigate the key pathways and genes associated with gastric adenocarcinoma via transcriptome sequencing. Five pairs of gastric adenocarcinoma tissue and normal tumor-adjacent tissue were harvested. After sequencing, raw data were processed and differentially expressed genes (DEGs) between tumor and control groups were screened, followed by functional enrichment analysis and gene clustering analysis. The effect of DEGs on patient prognosis was analyzed on the basis of the survival data from gastric adenocarcinoma patients in The Cancer Genome Atlas database. Several genes were validated through reverse transcription-quantitative polymerase chain reaction. In total, 1,477 upregulated and 282 downregulated DEGs were screened in tumor groups. These genes were segregated into four clusters. Genes in cluster 1 were significantly involved in metabolism of xenobiotics by cytochrome P450, genes in cluster 2 were majorly involved in apoptosis, tight junction formation, and platelet activation, genes in cluster 3 were primarily enriched in the p53 signaling pathway and genes in cluster 4 were significantly enriched in the insulin resistance pathway. Furthermore, 15 DEGs significantly influenced prognosis, including F2R, CTHRC1, and RASGRP3. The expression levels of CYP2B6, MAPK13, CTHRC, RASGRP3 and PYGM were consistent with our analysis results. In conclusion, pathways for metabolism of xenobiotics via cytochrome P450, apoptosis, tight junction formation, platelet activation, and insulin resistance may serve important roles in the progression of gastric adenocarcinoma. Notably, CTHRC1 and RASGRP3 may serve as key prognostic markers.

Reduced Expression of Deubiquitinase USP33 Is Associated with Tumor Progression and Poor Prognosis of Gastric Adenocarcinoma.

BackgroundUbiquitin-specific peptidase 33 (USP33) is a deubiquitinase that balances the ubiquitin status of proteins. It has been reported to act as a tumor suppressor in colorectal cancer and lung cancer. However, the expression pattern and clinical significance of USP33 have not been investigated in gastric adenocarcinoma (GAC).Material/MethodsWe explored the USP33 protein and RNA levels by immunohistochemistry (IHC), Western blot analysis, and qRT-PCR. The Pearson chi-square test was performed to evaluate the statistical associations between USP33 level and patient characteristics. Additionally, the relationship between USP33 expression and patient survival was investigated. Cellular studies, including proliferation assay, migration assay, and invasion assay, were conducted to demonstrate the underlying mechanisms of USP33 in GAC progression.ResultsThis study included 121 patients with GAC. USP33 showed a decreased expression in GAC tissues compared to adjacent normal gastric tissues. Low expression of USP33 was correlated with invasion depth and advanced TNM stage. According to survival analysis, upper location of tumor (P=0.003), invasion depth (P=0.048), advanced TNM stage (P=0.001), and low USP33 level (P=0.001) were all associated with poor overall survival of GAC patients. Cox analysis confirmed the independent role of USP33 in predicting patient survival. Cell experiments showed that USP33 overexpression significantly inhibited the proliferation, migration, and invasion of GAC cells.ConclusionsUSP33 was downregulated in GAC, and was an independent prognostic factor. In vitro results demonstrated the role of USP33 in suppressing tumor progression, suggesting that the developing an agonist of USP33 may be a novel direction for chemotherapy development.

Annexin A7 expression is downregulated in late-stage gastric cancer and is negatively correlated with the differentiation grade and apoptosis rate.

Annexin A7 is a member of the Annexin A family, which participates in various biological processes. Accumulating evidence has demonstrated that Annexin A7 serves an important role in tumorigenesis and is dysregulated in multiple types of cancer. However, the role of Annexin A7 in the tumorigenesis of gastric cancer remains to be determined. The present study revealed that Annexin A7 expression is downregulated in late-stage gastric cancer and is negatively correlated with the differentiation grade and apoptosis. There was a significant difference in Annexin A7 mRNA and protein expression in gastric cancer samples with distinct differentiation grades, with the lowest expression being observed in the highly differentiated cases. A terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling assay demonstrated that the apoptosis indices of highly, moderately and poorly differentiated gastric cancers were 18.12±2.40, 9.73±1.73 and 4.13±0.83%, respectively, with statistical significance (P<0.05). Flow cytometric analysis demonstrated that the apoptosis rates of gastric cancer MKN74, SGC7901 and BGC823 cells were 10.07±1.21, 7.11±1.04 and 4.25±1.02%, respectively, with statistical significance (P<0.05). Spearman's rank correlation analysis revealed that the Annexin A7 mRNA and protein levels were negatively correlated with the differentiation grade of the gastric cancer tissues, while the apoptosis index was positively correlated with the differentiation grade of the gastric cancer tissues. Furthermore, the apoptosis index was negatively correlated with Annexin A7 mRNA and protein expression. Similar associations were observed among Annexin A7 expression, differentiation grades and apoptosis in gastric cancer cell lines. The results of the present study demonstrated that Annexin A7 expression is downregulated, while apoptosis is upregulated, with the progression of gastric adenocarcinoma. These observations suggested that Annexin A7 may inhibit apoptosis during tumorigenesis and that it is a potential biomarker for the diagnosis, prognosis and treatment of gastric adenocarcinoma.

Expression of CD44v3, erythropoietin and VEGF-C in gastric adenocarcinomas: correlations with clinicopathological features.

To investigate the expression of CD44v3 and vascular endothelial growth factor C (VEGF-C) in gastric adenocarcinoma and the correlation with erythropoietin (EPO) and clinicopathological features. The expression of CD44v3, VEGF-C and EPO was evaluated by immunohistochemical staining in 169 gastric adenocarcinomas. The correlations between these parameters and patients' clinicopathological features were analyzed statistically. CD44v3 and VEGF-C were positive in 50 (29.6%) and 82 (48.5%) patients, respectively. High CD44v3 expression was associated with poor cellular differentiation, extensive lymph node metastasis and advanced stage of gastric adenocarcinoma (P <0.05). High VEGF-C expression was significantly correlated with Lauren type, extensive lymph node metastasis and advanced stage of gastric adenocarcinoma (P <0.05). Univariate analysis of survival demonstrated that patients with a strong CD44v3 immunoreaction had a significantly worse overall survival compared with patients showing a weak CD44v3 immunoreaction (log-rank test: P = 0.0449). The mean survival time of patients with low CD44v3 expression was 30.6 months, which was much longer than the 21.6 months in patients with high expression. In addition, a strong association between immunohistochemical expression of CD44v3 and EPO was noted. Increased expression of CD44v3 and VEGF-C may play a significant role in the carcinogenesis and progression of gastric adenocarcinoma. High CD44v3 expression may be a predictor of poor prognosis in gastric adenocarcinoma patients. We infer that some mechanisms may exist in regulating the expression of CD44v3 and EPO.

Evaluation of the expression and clinical value of lncRNA AC010761.9 in human gastric adenocarcinoma

BackgroundThe current study determined the expression and clinical value of lncRNA AC010761.9 in human gastric adenocarcinoma (GA).MethodsReal-time quantitative reverse transcription (qRT)-PCR was used to detect the level of lncRNA expression in 145 GA tissues and three GA cell lines, and the correlation between its level and clinicopathologic characteristics and potential corresponding mRNA of TNF receptor-associated factor 4 gene (TRAF4) was then evaluated.ResultsElevated lncRNA AC010761.9 was detected in all 6 GA tissues by previous lncRNA expression profile microarray assay. LncRNA AC010761.9 was over-expressed in 99 of 145 GA tissues (68.3%) with an elevated fold change of up to 35.14 compared to matched paracancerous tissues (p < 0.05), and was also over-expressed in the 3 GA cell lines (MGC803, BGC823, and SGC7901) compared to the normal gastric mucosal epithelial cell line (GES-1 cells; p < 0.05) by qRT-PCR. The elevated expression of this lncRNA was related to tumor size (p = 0.028), degree of differentiation (p = 0.047), and serum carbohydrate antigen (CA19-9) and carcinoembryonic antigen (CEA) concentrations (p = 0.026 and p = 0.037, respectively). Multivariate analysis further confirmed that the expression of lncRNA AC010761.9 was related to the degree of tumor differentiation (p = 0.015). Additionally, the expression of lncRNA AC010761.9 had a positive correlation with the mRNA expression of the potentially associated gene (TRAF4) in GA tissues (r = 0.385, p < 0.01).ConclusionsLncRNA AC010761.9 may be linked to GA progression and is a potential new biomarker for GA.

Decreased expression of insulin-like growth factor binding protein 6 is associated with gastric adenocarcinoma prognosis.

The present study aimed to investigate the expression and prognostic significance of insulin-like growth factor binding protein 6 (IGFBP-6) in gastric adenocarcinoma. The expression of IGFBP-6 was examined in 263 specimens from gastric adenocarcinoma patients using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blotting and immunohistochemical (IHC) staining. The association between IGFBP-6 expression, clinicopathological factors and clinical outcomes was investigated. Akaike information criterion (AIC) and Harrell's concordance index (c-index) were used to evaluate the accuracy of the predictive prognosis. RT-qPCR and western blotting results showed that IGFBP-6 mRNA expression was lower in the tumors compared with that in adjacent non-tumor tissues. IGFBP-6 showed significantly decreased expression in 170 out of 263 patients based on IHC data and this was associated with a larger tumor size (P<0.001) and poorly-differentiated adenocarcinoma (P=0.001), as well as with palliative gastrectomy (P=0.015). Additionally, decreased expression of IGFBP-6 was associated with stage T3/4a/4b disease and lymph node-positive metastasis (P<0.001). The association between decreased expression and a poor prognosis was revealed by Kaplan-Meier curves. Cox regression model identified IGFBP-6 as an independent prognostic factor. The prognostic value of the model with IGFBP-6 expression (AIC, 924.881; c-index, 0.878) was superior to that without IGFBP-6 expression (AIC, 947.164; c-index, 0.825). In conclusion, IGFBP-6 involves the development and progression of gastric adenocarcinoma, and its decreased expression predicts poor clinical outcomes.

The expression and significance of vascular endothelial growth factor in gastric adenocarcinoma and chronic atrophic gastritis with low grade intraepithelial neoplasia

Objective To investigate the expression and significance of vascular endothelial growth factor (VEGF) in gastric adenocarcinoma, normal gastric mucosa and chronic atrophic gastritis with low grade intraepithelial neoplasia. Methods Immunohistochemical streptavid-in-peroxidase (SP) method was used to detect the expression levels of VEGF in 65 cases of gastric cancer tissues, 50 cases of chronic atrophic gastritis with low grade intraepithelial neoplasia, and 35 cases of normal gastric mucosa (GM). The clinical data were reviewed in 65 patients with gastric adenocarcinoma. Results VEGF overexpression was seen in 2 cases of GM (2/35, 5.7%), 18 cases of chronic atrophic gastritis with low grade intraepithelial neoplasia (18/50, 36.0%), and 36 cases of gastric adenocarcinoma (36/65, 55.4%). Overexpression rate of VEGF in chronic atrophic gastritis with low grade intraepithelial neoplasia and gastric adenocarcinoma was significantly higher than that in the normal GM (P=0.001). Conclusion VEGF protein may play a certain role in the progression of gastric adenocarcinoma. It may also have significantly positive association with the oncegenesis and prognosis of the gastric cancer. Key words: Normal gastric mucosa; Gastric carcinoma; Vascular endothelial growth factor

Prognostic significance of autophagy-related proteins expression in resected human gastric adenocarcinoma.

Gastric adenocarcinoma (GC) is one of the most common malignancies in the world and one of the most frequent causes of cancer-related death. Autophagy is a highly regulated catabolic pathway responsible for the degradation of long-lived proteins and damaged intracellular organelles. However, the mechanism and guiding significance of autophagy in the development and progression of GC have remained to be elucidated. This study aimed to explore the clinicopathological significances and prognostic values of autophagy-related proteins AMBRA1 and Beclin-1 in GC. Quantum dots based immunofluorescence histochemistry (QDs-IHC) was performed to observe the expression of AMBRA1 and Beclin-1 proteins in the tissue microarrays including 163 specimens of GC and 20 noncancerous gastric tissues. Simultaneously, AMBRA1 and Beclin-1 proteins were detected by Western blotting in the 10 fresh GC and corresponding normal gastric tissues. The results showed that the expression levels of both AMBRA1 and Beclin-1 proteins were higher in GC tissues than in noncancerous gastric tissues by QDs-IHC and Western blotting (P<0.05). High AMBRA1 expression was detected in 90 of 163 (55.2%) GCs and high Beclin-1 expression was detected in 83 of 163 (50.9%) GCs. High AMBRA1 expression was closely related to depth of invasion, and lymph nodes metastasis (P<0.05). High expression of Beclin-1 protein was correlated with tumor grade (P<0.05). Positive correlation was observed between AMBRA1 and Beclin-1. Survival analysis indicated the high expression of AMBRA1 and Beclin- 1 was an independent factor in predicting poor overall survival (OS) of GC patients. These findings suggest the high expression of AMBRA1 and Beclin-1 proteins is significantly correlated with GC progression. High AMBRA1 and Beclin-1 expression heralds worse outcome of GC patients, suggesting a novel candidate prognostic marker and a therapeutic target for GC.

Up-Regulation of FOXC2 and FOXQ1 Is Associated with The Progression of Gastric-Type Adenocarcinoma.

Objective Forkhead box (FOX) proteins are important regulators of the epithelial-to-mesenchymal transition (EMT), which is the main mechanism of cancer metastasis. Different studies have shown their potential involvement in progression of cancer in different tissues such as breast, ovary and colorectum. In this study, we aimed to analyze the expression of genes encoding two FOX proteins in gastric adenocarcinoma. Materials and Methods In this experimental case-control study, the expression of FOXC2 and FOXQ1 was examined in 31 gastric adenocarcinoma tumors and 31 normal adjacent gastric tissues by reverse transcription polymerase chain reaction (PCR). Results The expression of both genes was significantly up-regulated in gastric adenocarcinoma tumors compared with the normal tissues (P<0.05). The differential expression of these two genes was also correlated with the grade of tumors (P<0.01). ConclusionWe show that up-regulation of FOXC2 and FOXQ1 are likely to be involved in the progression of gastric adenocarcinoma.

Association between CXCR2 and IL-22BP expression indicate a poor outcome for gastric adenocarcinoma progression.

C-X-C motif chemokine receptor type 2 (CXCR2), a key regulatory protein, has been associated with multiple roles in the progression of numerous tumors, including gastric adenocarcinoma (GA). However, the mechanism of CXCR2 in the development of tumors remains controversial and unclear. In a previous study, the expression of CXCR2 and interleukin-22 receptor 2 (IL-22BP) was observed in GA. This promoted the present study, which aimed to explore the association between the two proteins, and to further analyze their roles in GA. CXCR2 and IL-22BP protein expression was analyzed by immunohistochemistry and reverse transcription-quantitative polymerase chain reaction assays in gastric cancer (GC) tissue, additionally confirmed via western blotting and immunocytochemical analysis in the MKN-45, BGC-823 and SGC-7901 cell lines. The association between expression levels and clinicopathological characteristics was evaluated by the Mann-Whitney U and Kruskal-Wallis tests. Using Kaplan-Meier plots and Cox proportional hazard models, overall survival (OS) was analyzed. Compared with non-cancerous tissue, CXCR2 and IL-22BP were over expressed (P<0.001 and P<0.001, respectively), and were observed mainly in the cytoplasm (P=0.022 and P=0.014, respectively) in GA. The associated protein and messenger RNA levels were analyzed, and coexpression was identified. Increased expression and more positive cases of CXCR2 and IL-22BP were observed with advanced pathological tumor-node-metastasis (p-TNM) stage in GC (P<0.001 and P<0.001, respectively), as well as the presence and absence of lymph node metastasis (LNM) (P=0.003 and P=0.041, respectively) and deep or superficial muscular invasion (P=0.002 and P=0.004, respectively). In addition, an association between IL-22BP and tumor diameter was indicated (P=0.021). In a Kaplan-Meier analysis, compared with negative expression, the two proteins identified a group of patients with the shortest OS. Cox proportional hazard models revealed that the two proteins, in addition to p-TNM stage, LNM and depth of invasion, predicted a short time to OS. The coexpression of CXCR2 and IL-22BP was demonstrated in GA, which may indicate that CXCR2 is involved in more complex mechanisms and roles, and indicate a poor outcome in GA progression.

Mucin glycosylating enzyme GALNT2 suppresses malignancy in gastric adenocarcinoma by reducing MET phosphorylation.

Glycosylation affects malignancy in cancer. Here, we report that N- acetylgalactosaminyltransferase 2 (GALNT2), an enzyme that mediates the initial step of mucin type-O glycosylation, suppresses malignant phenotypes in gastric adenocarcinoma (GCA) by modifying MET (Hepatocyte growth factor receptor) activity. GALNT2 mRNA and protein were downregulated in GCAs, and this reduction was associated with more advanced disease stage and shorter recurrence-free survival. Suppressing GALNT2 expression in GCA cells increased cell growth, migration, and invasion in vitro, and tumor metastasis in vivo. GALNT2 knockdown enhanced phosphorylation of MET and decreased expression of the Tn antigen on MET. Inhibiting MET activity with PHA665752 decreased the malignant phenotypes caused by GALNT2 knockdown in GCA cells. Our results indicate that GALNT2 suppresses the malignant potential of GCA cells and provide novel insights into the significance of O-glycosylation in MET activity and GCA progression.

Serum VEGF-A and Tumor Vessel VEGFR-2 Levels Predict Survival in Caucasian but Not Asian Patients Undergoing Resection for Gastric Adenocarcinoma

Clinical trials of agents targeting the vascular endothelial growth factor A (VEGF-A) pathway in gastric adenocarcinoma (GA) suggest that these therapies may have varying efficacy in different races. VEGF-A in serum and/or VEGF receptor 2 (VEGFR-2) in CD31-positive tumor vessels (VEGFR-2/CD31) were measured in 118 Caucasians and 263 Asians who underwent gastric resection at two institutions and correlated with overall survival (OS). Blood was drawn before any treatment. Patients receiving neoadjuvant treatment were excluded from VEGFR-2 analysis. Compared with Asians, Caucasians were older (mean age 66-73 vs 59-62 years), had more proximal tumors, and had more advanced TNM stage. In the VEGF-A cohort, Caucasians had a median VEGF-A level that was 95 % higher than that of Asians and a much higher standard deviation (88 ± 6.206 vs 45 ± 76 pg/ml, p < 0.001). The 5-year OS for patients with low versus high VEGF-A levels was 72 versus 43 % in Caucasians (p = 0.001) and 86 versus 77 % in Asians (p = 0.236). In the VEGFR-2 cohort, OS was worse in Caucasians with high VEGFR-2/CD31 levels (49 vs 73 %, p = 0.038), while there was no significant difference in OS in Asians (80 vs 90 %, p = 0.119). On multivariate analyses of significant prognostic factors (excluding treatment factors and margin status), serum VEGF-A and tumor VEGFR-2/CD31 levels were independent predictors of OS only in Caucasians. In patients with resectable GA, VEGF-A and VEGFR-2/CD31 levels are independent predictors of OS in Caucasians but not in Asians, suggesting varying importance of this pathway in GA progression among different races.

Preoperative serum VEGF-A levels to predict survival for Caucasian and Asian patients undergoing resection for gastric adenocarcinoma.

81 Background: Clinical trials in gastric adenocarcinoma (GC) patients of vascular endothelial growth factor A (VEGF-A) targeted therapies have suggested these therapies may be more effective in Caucasians (CA) than in Asians (AS). Methods: Levels of VEGF-A in serum were measured in CA and AS treated at two institutions prior to potentially curative surgical resection for GC, and levels were correlated with overall survival (OS). Results: There were significant differences in CA (n=118) and AS (n=115) in terms of age (median 66 vs. 59), use of neoadjuvant (52% vs. 14%) and adjuvant therapy (27% vs. 18%), tumor location (58% upper/GE junction vs. 80% distal/middle), Lauren classification (57% vs. 46% intestinal), and TNM status (65% stage II or III vs. 55% stage I). CA had a median VEGF-A levels that was 95% higher than that of AS as well as a much higher standard deviation (88.1 + 6206 vs. 45.2 + 76.3 pg/ml, p&lt;0.001). CA with proximal/nondiffuse tumors had significantly higher VEGF-A levels than those with distal/nondiffuse or diffuse tumors (median 120 vs. 71 and 50 pg/ml; p=0.016). The 5-year OS for CA with low vs. high VEGF-A levels was 72.4% vs. 43.4% (p=0.001). In AS, there was no significant difference in 5-year OS according to VEGF-A level (77.4%% vs.85.6%, p=0.236). On multivariate analysis, tumor size, location, grade, N stage, and serum VEGF-A level were independent predictors of OS in CA. Conclusions: In patients with resectable GC, higher circulating VEGF-A levels are independently associated with decreased OS in CA but AS, suggesting varying importance of this angiogenic factor in GC progression among different races.