Poor Prognosis In Gastric Cancer Research Articles

Intraoperative blood loss does not independently affect the survival outcome of gastric cancer patients who underwent curative resection.

Whether intraoperative blood loss (IBL) was independently associated with poor prognosis of gastric cancer (GC) patients remains controversial. In the present study, we evaluated the impact of IBL on the disease-free survival (DFS) of GC patients. A total of 1669 patients who underwent curative gastrectomy for GC were reviewed retrospectively. All patients were classified as IBL < 400mL and IBL ≥ 400mL group according to the amount of IBL. The prognostic difference between two patient groups was compared and clinicopathologic factors associated with the prognosis of GC patients were analyzed. The 5-year DFS rate of the patients with IBL < 400mL and those with IBL ≥ 400mL was 52.1% and 41.5%, respectively (P < 0.001). The 5-year DFS rate of the patients who did and did not receive intraoperative blood transfusion was 36.9% and 53.2%, respectively (P < 0.001). However, the similar survival outcomes were not observed in the subgroup analysis based on the TNM stage. The multivariate analysis indicated that IBL (HR 1.021, 95% CI 0.875-1.191, P > 0.05) and intraoperative blood transfusion (HR 1.111, 95% CI 0.943-1.309, P > 0.05) were not independent prognostic factors for GC patients. In addition, the patients with IBL ≥ 400mL had a higher risk of postoperative complications than those with IBL < 400mL, especially for intraabdominal infection and wound infection. The tumor located in upper 1/3 stomach, total gastrectomy, combined organ resection and advanced tumor stage (stage III) were independent risk factors for intraoperative massive hemorrhage. Intraoperative blood loss was significantly associated with tumor-related and surgery-related factors. Intraoperative blood loss itself could not independently affect survival outcome of GC patients after curative gastrectomy.

Elevated epiregulin expression predicts poor prognosis in gastric cancer

Epiregulin (EREG) is a novel family member of EGF-like ligands and have elevated expression in a variety of human cancers. EREG expression promotes tumor progression and metastasis and reduces patient survival. However, the expression of EREG and its prognostic value are not clear in gastric cancer (GC). We assessed EREG mRNA and protein expression in GC tissues from Chinese patients using quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical staining of tissue microarray, and analyzed the correlation between the level of EREG expression and patient clinical characteristics and prognosis. We found that EREG expression was significantly higher in GC tissues than in matched adjacent noncancerous tissues. High EREG protein expression in GC was significantly associated with TNM stage including tumor size, lymph node metastases and distant metastases as well as poor overall survival. These finding demonstrate that EREG is an independent prognostic biomarker for GC.

GATA6 suppresses migration and metastasis by regulating the miR-520b/CREB1 axis in gastric cancer

Transcription factors (TFs) and microRNAs (miRNAs) are tightly linked to each other in tumor development and progression, but their interactions in gastric cancer (GC) metastasis remain elusive. Here we report a novel suppressive role of GATA6 in inhibiting GC metastasis by transactivating miR-520b. We found that GATA6 expression was significantly downregulated in metastatic GC cells and tissues and that its downregulation was correlated with a poor GC prognosis. Overexpression of GATA6 suppressed GC cell migration, invasion and metastasis both in vitro and in vivo. Luciferase reporter assays and chromatin immunoprecipitation assays demonstrated that miR-520b is a direct transcriptional target of GATA6. Moreover, miR-520b expression was positively correlated with GATA6 expression in GC tissues, and ectopic expression of miR-520b inhibited the migration and invasion of GC cells. Furthermore, cAMP responsive element binding protein 1 (CREB1) was identified as a direct and functional target of miR-520b, and GATA6 could suppress GC cell migration and metastasis via miR-520b-mediated repression of CREB1. Downregulation of GATA6 and miR-520b may partly account for the overexpression of CREB1 in GC. In conclusion, our results provide novel insight into the TF-miRNA regulatory network involved in GC metastasis. Targeting the GATA6/miR-520b/CREB1 axis may be an effective approach for GC treatment.

Tumor-associated neutrophils induce EMT by IL-17a to promote migration and invasion in gastric cancer cells

PurposeEpithelial to mesenchymal transition (EMT) can contribute to gastric cancer (GC) progression and recurrence following therapy. Tumor-associated neutrophils (TANs) are associated with poor outcomes in a variety of cancers. However, it is not clear whether TANs interact with the EMT process during GC development.MethodsImmunohistochemistry was performed to examine the distribution and levels of CD66 + neutrophils in samples from 327 patients with GC. CD66b + TANs were isolated either directly from GC cell suspensions or were conditioned from healthy donor peripheral blood polymorphonuclear neutrophils (PMNs) stimulated with tumor tissue culture supernatants (TTCS) and placed into co-culture with MKN45 or MKN74 cells, after which migration, invasion and EMT were measured. Interleukin-17a (IL-17a) was blocked with a polyclonal antibody, and the STAT3 pathway was blocked with the specific inhibitor AG490.ResultsNeutrophils were widely distributed in gastric tissues of patients with GC and were enriched predominantly at the invasion margin. Neutrophil levels at the invasion margin were an independent predictor of poor disease-free survival (DFS) and disease-specific survival (DSS). IL-17a + neutrophils constituted a large portion of IL-17a-producing cells in GC, and IL-17a was produced at the highest levels in co-culture compared with that in TANs not undergoing co-culture. TANs enhanced the migration, invasion and EMT of GC cells through the secretion of IL-17a, which activated the Janus kinase 2/signal transducers and activators of transcription (JAK2/STAT3) pathway in GC cells, while deprivation of IL-17a using a neutralizing antibody or inhibition of the JAK2/STAT3 pathway with AG490 markedly reversed these TAN-induced phenotypes in GC cells induced by TANs.ConclusionsNeutrophils correlate with tumor stage and predict poor prognosis in GC. TANs produce IL-17a, which promotes EMT of GC cells through JAK2/STAT3 signalling. Blockade of IL-17a signalling with a neutralizing antibody inhibits TAN-stimulated activity in GC cells. Therefore, IL-17a-targeted therapy might be used to treat patients with GC.

Stathmin gene silencing suppresses proliferation, migration and invasion of gastric cancer cells via AKT/sCLU and STAT3 signaling.

Globally, gastric cancer is the fifth most common malignancy, with high rates of incidence and mortality. The high mortality rate and poor prognosis of gastric cancer are closely associated with its profound invasiveness, high incidence of metastasis, rapid proliferation, and high rate of recurrence. Previous studies have confirmed that stathmin (STMN) has an important role in the occurrence, development and prognosis of gastric cancer. However, the detailed mechanisms by which STMN affects these processes remain unclear. The aim of the present study was to determine how STMN promotes invasion, migration and proliferation in gastric cancer tumor cells. The results of immunohistochemistry indicated that STMN is overexpressed in stomach neoplasm tissues, and that it is associated with migration, invasion, proliferation and anti‑apoptotic states of gastric cancer cells. The secretory proteins of gastric cancer cells with or without STMN knockdown were further analyzed using the isobaric tags for relative and absolute quantitation method to identify differentially expressed proteins verified by reverse transcription‑quantitative polymerase chain reaction and western blot analysis. Inhibition of STMN decreases the levels of clusterin, cystatinC and matrix metalloproteinases, followed by inhibiting the protein kinaseB and signal transducer and activation of transcription activation. These findings suggest that STMN could be a promising therapeutic target for gastric cancer.

Preoperative Anemia or Low Hemoglobin Predicts Poor Prognosis in Gastric Cancer Patients: A Meta-Analysis.

Background The prognostic value of preoperative anemia in gastric cancer remains unclear. Therefore, the purpose of the present study is to evaluate the prognostic value of preoperative anemia in gastric cancer. Methods We searched Embase and PubMed databases for relevant studies from inception to March 2018. The prognostic value of preoperative anemia in gastric cancer was determined by calculating the hazard ratio (HR) and the corresponding 95% confidence interval (CI) as effect measures. A random effect model was used in cases in which there was significant heterogeneity; otherwise, a fixed effect model was used. Statistical analyses were performed using Stata software. Results Seventeen studies involving 13,154 gastric cancer patients were included. The estimated rate of preoperative anemia was 36% (95%CI = 27-44%). The overall survival of preoperative anemia was poor (HR = 1.33, 95%CI = 1.21-1.45). Moreover, disease-free survival was significantly lower in patients with preoperative anemia compared with those without this condition (HR = 1.62, 95%CI = 1.13-2.32). These findings were corroborated by the results of subgroup analyses. Conclusions The results indicate that preoperative anemia predicts poor prognosis in gastric cancer, including overall survival and disease-free survival. Therefore, preoperative anemia may be a convenient and cost-effective blood-derived prognostic marker for gastric cancer.

Characterization of the prognostic values of the NDRG family in gastric cancer.

Background:The N-myc downstream-regulated gene (NDRG) family, NDRG1-4, has been involved in a wide spectrum of biological functions in multiple cancers. However, their prognostic values remain sparse in gastric cancer (GC). Therefore, it is crucial to systematically investigate the prognostic values of the NDRG family in GC.Methods:The prognostic values of the NDRG family were evaluated by Kaplan–Meier Plotter and SurvExpress. The mRNA of the NDRG family was investigated in The Cancer Genome Atlas (TCGA). Transcription factors (TFs) and miRNAs associated with the NDRG family were predicted by NetworkAnalysis. The prognostic values of DNA methylation levels were analyzed by MethSurv. The correlation between immune cells and the NDRG family was evaluated by the Tumor Immune Estimation Resource (TIMER) database.Results:High levels of mRNA expression of NDRG2 and NDRG3 were associated with a favorable prognosis in all GCs. In HER2− GC, NDRG1 was significantly associated with a poor prognosis of GC [hazard ratio (HR) = 1.65, 95% confidence interval (CI) = 1.16–2.33, p = 0.0046]. In HER2+ GC, NDRG4 showed a poor prognosis (HR = 1.4, 95% CI: 1.06–1.85, p = 0.017). NDRG4 was an independent prognostic factor in recurrence-free survival by TCGA cohort. The low-risk NDRG-signature group displayed a significantly favorable survival outcome than the high-risk group (HR = 1.76, 95% CI: 1.2–2.59, p = 0.00385). The phosphorylated protein NDRG1 (NDRG1_pT346) displayed a favorable overall survival and was significantly associated with HER2 and phosphorylated HER2. Epidermis development was the top biological process (BP) for coexpressed genes associated with NDRG1 and NDRG4, while mitotic nuclear division and mitotic cell processes were the top BPs for NDRG2 and NDRG3, respectively. Overall, 6 CpGs of NDRG1, 4 CpGs of NDRG2, 3 CpGs of NDRG3 and 24 CpGs of NDRG4 were associated with significant prognosis. CD4+ T-cells showed the highest correlation with NDRG4 (correlation = 0.341, p = 2.14e−11). Furthermore, BCL6 in follicular helper T-cells (Tfh) cells showed the highest association with NDRG4 (correlation = 0.438, p = 00e+00).Conclusions:This study analyzed the multilevel prognostic values and biological roles of the NDRG family in GC.

The Value of Serum Immunoglobulin G Glycome in the Preoperative Discrimination of Peritoneal Metastasis from Advanced Gastric Cancer.

Background: Peritoneal metastasis, associated with poor prognosis in gastric cancer, is difficult to discriminate from advanced gastric cancer preoperatively. However, operative diagnosis could bring both mental and physical trauma and economic burden for patients. Consequently, a non-invasive biomarker is necessary to reduce the burden of operative diagnosis and improve survival quality of patients. This study aims to elucidate the correlation between Immunoglobulin G (IgG) N-glycome and peritoneal metastasis and find potential biomarkers in preoperative discrimination of peritoneal metastasis from advanced gastric cancer based on the comprehensive sample set.Methods: A total of 373 gastric cancer patients were enrolled and randomly sorted into training cohort (n=249) and validation cohort (n=124). The IgG N-glycome composition was analyzed by ultra-performance liquid chromatography.Results: Twenty-four glycan peaks were directly detected and 15 traits based on the same structures were evaluated between peritoneal metastasis group and advanced gastric cancer group. Several differences in IgG glycosylation were found: sialylation and fucosylation were increased in peritoneal metastasis, while neutral glycosylation, monogalacosylation and bisecting GlcNAc were decreased. Based on the significant glycomics profile, a glyco-model composed of five glycan peaks (GP6, GP9, GP11, GP21 and GP23) was established with area under the receiver operating characteristic curve (AUC) value of 0.80 (training cohort) and 0.77 (validation cohort), which showed good potential in discriminating peritoneal metastasis from advanced gastric cancer. The diagnostic performance of this model was further validated in a combined cohort (AUC=0.79). Two patients with gastric cancer were selected to perform and demonstrate the usage of the diagnostic workflow.Conclusions: Here we firstly present IgG glycome profiles in a large number of preoperative peritoneal metastasis serums. The IgG glycan was highly associated with peritoneal metastasis. These findings enhance the understanding of peritoneal metastasis. Besides, our results suggested that the newly established glyco-model could be a reliable predictor of the presence of peritoneal metastasis in patients with advanced gastric cancer.

Elevated serum levels of interleukin-37 correlate with poor prognosis in gastric cancer.

interleukin-37 (IL-37) is as a natural suppressor of the innate inflammatory and immune responses. It has also been reported to be involved in carcinogenesis and metastasis. The present case-control study was designed to investigate the role of serum levels of IL-37 in patients with gastric cancer. serum IL-37 levels were determined using the enzyme-linked immunosorbent assay in 180 patients diagnosed with gastric cancer and 100 healthy controls. The association between IL-37 levels and clinical factors was assessed. Univariate and multivariate analyses were performed to investigate the prognostic significance of these parameters in gastric cancer. serum IL-37 levels in gastric cancer patients (5.606 ± 0.837 pg/ml) were significantly higher than those in healthy controls (2.364 ± 0.210 pg/ml, p < 0.001). High serum IL-37 levels were related to a poorly differentiated histologic type (p = 0.046) and advanced T stage (p = 0.003). The Kaplan-Meier survival analysis indicated that the high-IL-37 group had a poorer overall survival and progression-free survival (overall survival [OS]: 39.0 months vs 13.0 months, p < 0.001, progression-free survival [PFS]: 25.0 months vs 10.0 months, p < 0.001). Multivariate analyses showed serum IL-37 to be an independent prognostic factor for gastric cancer patients (OS: hazard ratios [HR] = 1.842, 95% CI: 1.190-2.854, p = 0.006; PFS: HR = 1.547, 95% CI: 1.014-2.359, p = 0.043). in conclusion, serum IL-37 levels were associated with poor overall survival and progression-free survival in gastric cancer patients. IL-37 may be a potential predictor of prognosis in gastric cancer.

Gastric cancer patient with c-MET amplification treated with crizotinib after failed multi-line treatment: A case report and literature review

Gastric cancer is one of the most common gastrointestinal tumors. Most patients have been in advanced stage at diagnosis and lack effective treatment. Molecular targeted drugs have become new therapeutic strategies. MET is an important driving gene for the development of gastric cancer. MET gene amplification and protein over-expression are closely related to the invasion and metastasis, late stage and poor prognosis of gastric cancer. Crizotinib is a small molecule inhibitor against MET. There are few reports of crizotinib in gastric cancer patients with c-MET amplification. This article reports a case of c-MET gene amplification in advanced gastric cancer with liver metastases. After 2 months of treatment with crizotinib, liver lesions were completely relieved and progression-free survival lasted for up to 20 months.

Plasmacytoid Dendritic Cells and ICOS+ Regulatory T Cells Predict Poor Prognosis in Gastric Cancer: A Pilot Study

Background: Regulatory T cells (Tregs) and plasmacytoid dendritic cells (pDCs) are the main immunosuppressive cells in tumor microenvironment of gastric cancer (GC). In this prospective study, the association of prognosis with Tregs subsets and pDCs were further analyzed.Methods: pDCs, Tregs population and its expression of inducible costimulator (ICOS) were analyzed in peripheral blood from 41 GC patients by multicolor flow cytometry. These cell populations in carcinoma tissue, peritumor tissue and normal gastric mucosa from 87 GC patients were also detected by immunohistochemistry and double immunofluorescence.Results: Both ICOS+Foxp3+Treg cells (P=0.0341 and P=0.0298, respectively) and pDC (P=0.0237 and P=0.0083, respectively) in peripheral blood and tumor tissue could predict poor clinical outcome in GC patients. However, the total Foxp3+Tregs in the GC tissue didn't correlated with the outcome (P=0.4299). No correlation of CD4+ T cell or CD8+ T cell frequency could be found with clinical outcome neither in peripheral blood nor in tumor tissue.Conclusions: ICOS+Tregs and pDCs could predict poor prognosis of GC, targeting ICOS-L/ICOS costimulation axis may be a potential treatment for GC.

Low expression of PDHA1 predicts poor prognosis in gastric cancer

PDH E1 component subunit alpha (PDHA1) has been reported to be biologically significant in several human tumors. The aim of this study was to investigate the expression of PDHA1 in gastric cancer (GC) and its relationship with clinicopathological characteristics and prognosis. Oncomine analysis of neoplastic vs. normal tissue showed that the mRNA levels of PDHA1 were significantly underexpressed in different types of GC across three analyses. Underexpression of PDHA1 was found in intestinal-type GC (P = 0.009), diffuse-type GC (P = 0.036), and mixed-type GC (P = 0.025). Immunohistochemical staining of the 174 GC tissue microarray showed that PDHA1 staining is much stronger in normal mucosa than in GC samples (P = 0.040). Furthermore, PDHA1 expression levels were found to be significantly lower in 69.05% (87/126) of poorly differentiated GCs as compared to the well or moderately differentiated ones (P = 0.037). Intriguingly, PDHA1 expression was significantly correlated with depth of invasion (P < 0.001), lymph node metastasis (P < 0.001), TNM stage (P < 0.001), and nerve invasion (P = 0.006). However, it was not correlated with gender, age, Lauren classification, and lymphovascular invasion (P > 0.05 for all). Kaplan-Meier analysis revealed that low tumor expression of PDHA1 was significantly correlated with a poorer overall survival in patients with GC (5-year overall survival rates for patients with low vs high PDHA1 expression = 49.8% vs 72.7%, hazard ratio of death from GC = 2.594, 95% CI = 1.527 to 4.408, P < 0.001). Multivariate analysis showed that PDHA1 (P = 0.025) was an independent predictor of overall survival. These findings are of potential clinical utility and merit further validation.

Plastin3 is associated with epithelial-mesenchymal transition and poor prognosis in gastric cancer.

The plastin3 (PLS3) gene, which encodes an actin bundling protein known to inhibit cofilin-mediated depolymerization of actin fiber, has been previously reported to serve an important role in the epithelial-mesenchymal transition (EMT) in cancer. The aim of the present study was to determine the clinical significance of PLS3 and its role in regulating EMT, as well as in promoting cell invasion and migration in gastric cancer. The expression of plastin3 mRNA was measured in 163 resected gastric cancer specimens, in order to determine the clinicopathological significance. Furthermore, in vitro invasion and migration assays were performed on gastric cancer cells, which revealed that PLS3 expression was suppressed. The high PLS3 expression group had a higher incidence of advanced tumour stage, cancer differentiation, tumour invasion depth and distant metastases compared with the low PLS3 expression group (P<0.05). In addition, the high PLS3 expression group had a significantly poorer prognosis than the low expression group (P=0.012). Multivariate analysis indicated that high PLS3 expression was an independent prognostic factor for survival. The present study also identified that suppression of PLS3 in gastric cancer cells was associated with decreased cell invasion and migration. The findings from the present study indicate that high expression of PLS3 in gastric cancer is independently associated with a poor prognosis, and that PL3 serves an important role in EMT.

Low STYK1 expression indicates poor prognosis in gastric cancer.

BackgroundThe expression of serine threonine tyrosine kinase 1 (STYK1), a member of the receptor protein tyrosine kinase (RPTK) family, is abnormal in several cancers. However, the molecular mechanism of STYK1 regulation of gastric cancer (GC) progression is unknown.Materials and methodsWe evaluated STYK1 expression in GC tissues and the corresponding normal tissues. Specimens from 93 patients with GC were examined with immunohistochemical staining. The relationship between STYK1 protein expression and the patients’ clinicopathological features was assessed. Kaplan–Meier and Cox proportional regression analyses were used to evaluate the association between STYK1 expression and survival.ResultsSTYK1 expression was decreased in GC tissues. Low STYK1 expression was significantly associated with poor tumor differentiation (P=0.023), advanced clinical stage (P=0.021), and poor overall survival (OS; P=0.034). Univariate and multivariate analyses revealed that STYK1expression was an independent prognostic indicator (HR =0.53, 95% CI =0.29–0.95, P=0.039; HR =0.51, 95% CI =0.24–0.91, P=0.030, respectively).ConclusionDownregulated STYK1 expression correlated significantly with poor tumor differentiation, advanced clinical stage, and poor OS in GC. STYK1 might be a diagnostic and prognostic indicator in patients with GC.

Circ_0009910 regulates growth and metastasis and is associated with poor prognosis in gastric cancer.

Circular RNAs (circRNAs) have recently shown capabilities as gene regulators in mammals. In this study, we aimed to evaluate the effects and mechanism of circ_0009910 in gastric cancer (GC). Circ_0009910 expression was quantified by Real-time PCR in human GC cell lines and tissues. Association between circ_0009910 levels and clinicopathological factors and patient's prognosis was analyzed. The roles of circ_0009910 in regulating GC cell proliferation, colony formation, migration, and invasion were evaluated in vitro. Western blot analysis was conducted to detect the expressions of molecular markers of epithelial-mesenchymal transition (EMT). Circ_0009910 expression level was elevated in GC tissues and cell lines and associated with clinical stage (p = 0.032), distant metastasis (p = 0.028) and differentiation (p = 0.007). Kaplan-Meier survival analysis indicated that circ_0009910 expression in positive group has a worse overall survival compared to the negative group (p = 0.0013). Multivariate analysis showed that circ_0009910 was an independent risk factor for GC (HR = 2.346, 95% CI: 1.673-3.775, p = 0.006). Knockdown of circ_0009910 expression can suppress BGC823 and AGS cells proliferation, migration and invasion in vitro experiments. The results of Western blot indicated that knockdown of circ_0009910 increased expression of E-cadherin and decreased expression of the mesenchymal markers, snail and N-cadherin. Altogether, we demonstrate that circ_0009910 acts as a prognostic biomarker and promote cell proliferation, migration, invasion and EMT in GC, indicating that circ_0009910 may be a novel potential biomarker and therapeutic target of GC.

Transmembrane protein GRINA modulates aerobic glycolysis and promotes tumor progression in gastric cancer

BackgroundRecent observations indicate a decreased cancer risk in patients with Alzheimer’s disease (AD). AD is a severe neurodegenerative disorder characterized by progressive cognitive decline. The 8q24 region has been shown to be involved in AD aetiology. We aimed to identify and explore the potential oncogenes or antioncogenes on chromosome 8q24.MethodsWe compared expression of genes on Chromosome 8q24 in 32 pairs of samples from The Cancer Genome Atlas (TCGA) database. We conducted bioinformatics analysis of the commonly used gastric cancer databases and performed clinical verification of gastric cancer samples, combined with assessment of biological function both in vitro and in vivo to determine the relationship between upregulated expression of GRINA and gastric cancer progression. We also explored the molecular mechanism of GRINA upregulation and its function in gastric cancer development and progression.ResultsThe expression of GRINA in cancer tissues was significantly higher than that in normal tissues. GRINA indicated poor prognosis in gastric cancer. GRINA promoted the proliferation, migration and invasion capacity of gastric cancer cells. GRINA was transcriptionally mediated by c-Myc and promotes cell cycle transition. GRINA knockdown decreased PI3K/Akt/mTOR signaling and glycolytic metabolism in gastric cancer cells. The apoptosis rate was significantly increased in gastric cancer cell lines after knockdown of GRINA. The expression of pro-apoptotic protein Bax was significantly upregulated, whereas the anti-apoptotic protein Bcl-2 was significantly downregulated in GRINA silenced cells.ConclusionsHuman gastric cancers have increased levels of GRINA, which promotes growth of gastric cancer and inhibits tumor cells apoptosis.

Significant association of DIRC1 overexpression with tumor progression and poor prognosis in gastric cancer.

DIRC1, Disrupted in Renal Cancer 1, was identified as a breakpoint-spanning gene in a chromosomal translocation, which was associated with the onset and progression of some cancers. However, the expression in human gastric cancer (GC) and the role of DIRC1 in human gastric tumorigenesis are unknown. Thereby, the main purpose of this study was to unearth the association of DIRC1 with GC. By analyzing The Cancer Genome Atlas (TCGA) datasets, the expression of DIRC1 in GC and normal gastric tissues were compared. Besides, its association with clinicopathological significance, overall survival (OS) and independent prognosis were analyzed by Pearson's x2 test, Kaplan-Meier method and Cox proportional hazards model, respectively. Functionally, the knockdown of DIRC1 was performed by siRNA method; moreover, its effects on the proliferation and metastasis of GC cells were examined by CCK-8 and transwell assays. Furthermore, the key markers of protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling were tested by Western blot assay. The results showed that high expression of DIRC1 was found in GC tissues compared with normal gastric tissues. High expression of DIRC1 was associated with more cases of severer tumor malignancy and shorter OS; besides, high-level of DIRC1 was suggested to be an independent prognostic factor for GC. Furthermore, the knockdown of DIRC1 inhibited SGC-7901 GC cells proliferation, migration and invasion. Mechanically, the activity of AKT/mTOR signaling was suppressed by the knockdown of DIRC1. These findings offer clinical associations and an in vitro evidence showing that the knockdown of DIRC1 impeded the GC carcinogenicity possibly via suppression of AKT/mTOR signaling. This work might provide a potential therapeutic target for GC treatment.

High expression of ALPPL2 is associated with poor prognosis in gastric cancer

Alkaline phosphatase placental-like 2 (ALPPL2) is a member of the ALPP alkaline phosphatase family and is reported to be associated with the growth of some tumors. Gastric cancer is one of the most common cancers worldwide. We previously identified a distinct expression pattern of ALPPL2 between gastric cancer and adjacent normal tissues. In this study, we examined the expression of ALPPL2 in gastric adenocarcinoma and its ability to predict prognosis. We used bioinformatics analysis and immunohistochemistry to examine the expression pattern of ALPPL2 and analyzed the associations between ALPPL2 level and perioperative characteristics and the prognosis of gastric adenocarcinoma patients by Kaplan-Meier plotter analysis. Our results indicated that the expression of ALPPL2 was significantly increased in gastric adenocarcinoma (P < .01) and was an independent factor (P < .05) that could provide reliable prognostic information on gastric adenocarcinoma patients. High expression of ALPPL2 was associated with advanced TNM stage (P < .05) and high HER-2 expression (P < .01). Our study suggests that ALPPL2 has the potential to reveal prognostic information on gastric cancer.

Investigating Potential Molecular Mechanisms of Carcinogenesis and Genes as Biomarkers for Prognosis of Gastric Cancer Based on Integrated Bioinformatics Analysis

Gastric cancer, as the fifth most common malignancy worldwide, is a deadly disease afflicting nearly a million people. Researchers have devoted much to study the mechanisms of carcinogenesis and progression, but the exact information of tumor initiation and progression is remained largely unknown. Here, we hypothesized several differentially expressed genes and possible pathways by employing integrated bioinformatics analysis. We fully analyzed four gastric cancer-related microarray datasets to screen differentially expressed mRNAs (DEMs), miRNAs (DEMis) and lncRNAs (DELs). The functional enrichment analysis was deeply construed, PPI network and ceRNA regulatory network were constructed to investigate potential mechanisms of tumorigenesis and progression. Furthermore, survival analysis was performed to identify critical lncRNAs that may significantly affect pathogenesis of gastric cancer. QRT-PCR was applied to verify our result. We identified two hub subnetworks that may explain the progression, metastasis and poor prognosis of gastric cancer. Meanwhile, several potential significant lncRNAs were identified. In summary, we ascertained several significantly changed KEGG pathways in the tumor initiation and progression. We also hypothesized several lncRNAs that contribute to poor prognosis of gastric cancer via integrated bioinformatics, which deserve further investigation.

Long noncoding RNA LINC00165-induced by STAT3 exerts oncogenic properties via interaction with Polycomb Repressive Complex 2 to promote EMT in gastric cancer

Long non-coding RNAs (lncRNAs) are a crucial member of the non-coding RNA family, and increasing evidence demonstrates that lncRNAs participate in the initiation and progression of cancers. Our study aimed to explore the role of the lncRNA LINC00165 in gastric cancer (GC) development. In the present study, our results showed that LINC00165 was upregulated in GC tissues and cell lines and high expression of LINC00165 was correlated with tumor-node-metastasis stage, invasion depth, and overall survival of GC patients. Functional assays showed that LINC00165 knockdown inhibited the proliferation, migration and invasion of GC cells and LINC00165 overexpression stimulated their proliferation, migration and invasion. Online transcription factor binding site prediction analysis showed that there were STAT3 binding sites in the LINC00165 promoter region. Furthermore, luciferase reporter and chromatin immunoprecipitation assays provided evidence that STAT3 could bind directly to the region between −547 bp to −537 bp (ATGTTGGGAAA) of LINC00165 promoter and activate its transcription. Then GC cells were partitioned into nuclear and cytoplasmic fractions and we found that LINC00165 was localized preferentially to the nucleus. Mechanistically, we revealed that LINC00165 functioned as a scaffold for interaction with Polycomb Repressive Complex 2 to promote the epithelial-mesenchymal transition in GC cells. Taken together, our study revealed that LINC00165 was involved in the progression and poor prognosis of GC as an oncogenic role. Therefore, LINC00165 might become a new potential target for GC chemotherapy and further predict prognosis of patients.