Prognosis Of Gastric Carcinoma Research Articles

An Advanced Systems Pharmacology Strategy Reveals AKR1B1, MMP2, PTGER3 as Key Genes in the Competing Endogenous RNA Network of Compound Kushen Injection Treating Gastric Carcinoma by Integrated Bioinformatics and Experimental Verification.

Gastric carcinoma (GC) is a severe tumor of the digestive tract with high morbidity and mortality and poor prognosis, for which novel treatment options are urgently needed. Compound Kushen injection (CKI), a classical injection of Chinese medicine, has been widely used to treat various tumors in clinical practice for decades. In recent years, a growing number of studies have confirmed that CKI has a beneficial therapeutic effect on GC, However, there are few reports on the potential molecular mechanism of action. Here, using systems pharmacology combined with proteomics analysis as a core concept, we identified the ceRNA network, key targets and signaling pathways regulated by CKI in the treatment of GC. To further explore the role of these key targets in the development of GC, we performed a meta-analysis to compare the expression differences between GC and normal gastric mucosa tissues. Functional enrichment analysis was further used to understand the biological pathways significantly regulated by the key genes. In addition, we determined the significance of the key genes in the prognosis of GC by survival analysis and immune infiltration analysis. Finally, molecular docking simulation was performed to verify the combination of CKI components and key targets. The anti-gastric cancer effect of CKI and its key targets was verified by in vivo and in vitro experiments. The analysis of ceRNA network of CKI on GC revealed that the potential molecular mechanism of CKI can regulate PI3K/AKT and Toll-like receptor signaling pathways by interfering with hub genes such as AKR1B1, MMP2 and PTGERR3. In conclusion, this study not only partially highlighted the molecular mechanism of CKI in GC therapy but also provided a novel and advanced systems pharmacology strategy to explore the mechanisms of traditional Chinese medicine formulations.

GNEN-1: a spontaneously immortalized cell line from gastric neuroendocrine neoplasia.

Mixed neuroendocrine-non-neuroendocrine neoplasms (MINEN) are rare tumors that consist of at least 30% of both neuroendocrine and non-neuroendocrine components. The data concerning the pathogenesis of MINEN suggest a monoclonal origin. We describe a spontaneously immortalized cell line derived from gastric MINEN called GNEN-1. Primary tumor consisted of components of high-grade neuroendocrine carcinoma and adenocarcinoma. The GNEN-1 cell line was initiated from metastatic tumor cells of peritoneal fluid and expresses a purely neuroendocrine phenotype. The GNEN-1 cell line grows as monolayers and has retained the neuroendocrine phenotype with positivity for chromogranin A in immunohistochemistry. Electron microscopy showed cytoplasmic dense core granules and axon hillocks. The karyotype revealed alterations typical of both adenocarcinoma and neuroendocrine carcinoma such as trisomy 7 and 8. GNEN-1 cells were also positive for stanniocalcin-1, a marker of poor prognosis in gastric carcinomas. Expression of several markers related to neuroendocrine tumors was found. There have been only a few studies on the pathogenesis of MINEN and management of the disease due to the rarity of this tumor type. Here we describe for the first time an immortalized cell line derived from mixed gastric NEN. The GNEN-1 line offers a tool for future research on gastric NEN.

Circular RNA PLEC acts as a sponge of microRNA-198 to promote gastric carcinoma cell resistance to paclitaxel and tumorigenesis

Gastric carcinoma (GC) is one of the most frequent types of malignancy worldwide. Resistance to paclitaxel (PTX) has become an obstacle to the prognosis of GC, and the underlying mechanism is not clear. A previous study identified GC-related circRNAs via microarray analysis and bioinformatics analysis, and we discovered that circPLEC (hsa_circ_104722) was markedly upregulated in GC tissues and cells. The molecular mechanism of circPLEC in PTX-resistant GC cells still needs to be explored. In the present study, qRT-PCR demonstrated that circPLEC was upregulated in PTX-resistant GC tissues and cells, indicating that circPLEC boosts the PTX resistance of GC. circPLEC downregulation weakened GC resistance to PTX and tumorigenesis, migration and invasion and promoted the apoptosis of PTX-resistant GC cells. MiR-198 inhibitor reversed the effect of circPLEC downreguAlation in PTX-resistant GC cells, and MUC19 downregulation weakened GC resistance to PTX and tumorigenesis and improved the apoptosis of PTX-resistant GC cells. In summary, circPLEC acts as a sponge of miR-198 to promote the PTX resistance and tumorigenesis of GC cells by regulating MUC19 expression.

Kinase DYRK2 Acts as a Regulator of Autophagy and an Indicator of Favorable Prognosis in Gastric Carcinoma

Background: Gastric cancer (GC) is the third leading cancer-causing death worldwide. Therefore, new and more specific molecules for GC are needed. Here, we found that dual specificity tyrosine phosphorylation regulated kinase 2 (DYRK2) may be a specific marker for GC. Methods: The immunohistochemistry, statistical and bioinformatics analyses were used to detect the DYRK2 expression in stomach tissues. The role of DYRK2 in GC was analysed via nude mouse model, CCK8, wound healing and transwell assays. The Western blotting and immunofluorescent experiments were also performed to show the relationship between DYRK2 expression and epithelial-mesenchymal transition (EMT) / autophagy progress. Findings: We found that DYRK2 expression in GC tissues was lower than that in benign or normal tissues, and patients with high DYRK2 expression had a good prognosis. In vitro, the results showed that DYRK2 expression inhibited the tumorigenic activities of GC, including proliferation, migration, and invasion. By analyzing the expression of EMT markers after altering DYRK2 expression, we found that DYRK2 inhibits the occurrence of EMT. The nude mouse model also indicated that DYRK2 does indeed inhibit tumor growth. Finally, we reported that DYRK2 promotes autophagy by Western blotting and immunofluorescent technology. Interpretation: DYRK2 may be a good reference indicator for the clinical diagnosis of GC. Funding Statement: This work was supported by the National Natural Science Foundation of China (81572390, 81874067); Jiangsu Provincial Science and Technology Department Social Development - Clinical Frontier Technology (BE2018673); the 13th Five Years Key Talent's Subsidy Project in Science and Education of Jiangsu Province (ZDRCA2016051). Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: The research method was approved by the Human Research Ethics Committee of the Affiliated Hospital of Nantong University, and the review number is 2018-K020. All studies involving animals were approved by the Nantong University Institutional Animal Care and Use Committee (No. 20150307-006).

Identification of pivotal genes associated with the prognosis of gastric carcinoma through integrated analysis.

Purpose: Detecting and diagnosing gastric cancer (GC) during its early period remains greatly difficult. Our analysis was performed to detect core genes correlated with GC and explore their prognostic values.Methods: Microarray datasets from the Gene Expression Omnibus (GEO) (GSE54129) and The Cancer Genome Atlas (TCGA)-stomach adenocarcinoma (STAD) datasets were applied for common differentially co-expressed genes using differential gene expression analysis and Weighted Gene Co-expression Network Analysis (WGCNA). Functional enrichment analysis and protein–protein interaction (PPI) network analysis of differentially co-expressed genes were performed. We identified hub genes via the CytoHubba plugin. Prognostic values of hub genes were explored. Afterward, Gene Set Enrichment Analysis (GSEA) was used to analyze survival-related hub genes. Finally, the tumor-infiltrating immune cell (TIC) abundance profiles were estimated.Results: Sixty common differentially co-expressed genes were found. Functional enrichment analysis implied that cell–cell junction organization and cell adhesion molecules were primarily enriched. Hub genes were identified using the degree, edge percolated component (EPC), maximal clique centrality (MCC), and maximum neighborhood component (MNC) algorithms, and serpin family E member 1 (SERPINE1) was highly associated with the prognosis of GC patients. Moreover, GSEA demonstrated that extracellular matrix (ECM) receptor interactions and pathways in cancers were correlated with SERPINE1 expression. CIBERSORT analysis of the proportion of TICs suggested that CD8+ T cell and T-cell regulation were negatively associated with SERPINE1 expression, showing that SERPINE1 may inhibit the immune-dominant status of the tumor microenvironment (TME) in GC.Conclusions: Our analysis shows that SERPINE1 is closely correlated with the tumorigenesis and progression of GC. Furthermore, SERPINE1 acts as a candidate therapeutic target and prognostic biomarker of GC.

Relationship Between Postoperative Complications and the Prognosis of Gastric Carcinoma Patients Who Underwent Surgical Resection: A Systematic Review and Meta-Analysis.

Background:Whether the presence of postoperative complications was associated with poor prognosis of gastric carcinoma (GC) patients remain controversial. This meta-analysis was designed and reported to compare the survival difference between patients with complications and non-complications.Methods:Cochrane Library, PubMed and Embase databases were comprehensively searched for published literatures to review current evidence on this topic. The survival data were extracted, and a random-effect or fixed-effect model was used to analyze the correlation between postoperative complications and oncologic outcome of GC patients.Results:Of all studies identified, 32 were eligible for this pooled analysis, with a total of 32,067 GC patients. The incidence of postoperative complications was approximately 12.5% to 51.0%. Among them, infectious complications varied from 3.0% to 28.6%, anastomotic leakage varied from 1.1% to 8.7% and postoperative pneumonia varied from 1.6% to 12.8%. The presence of postoperative complications resulted in a significant poorer overall survival (OS) of gastric carcinoma patients (hazard ratio [HR]:1.49, 95% confidence interval [CI]: 1.33-1.67, P < 0.001). Additionally, the pooled results showed a significant correlation between infectious complications and decreased OS (HR: 1.61, 95%CI: 1.38-1.88, P < 0.001). Concerning specific postoperative complications, we found that both anastomotic leakage (HR: 2.36, 95%CI: 1.62-3.42, P < 0.001) and postoperative pneumonia (HR: 1.74, 95%CI: 1.22-2.49, P = 0.002) impaired the OS of gastric carcinoma patients.Conclusion:Postoperative complications were significantly correlated to recurrence and poor survival in gastric carcinoma patients. To gain a better surgical outcome and long-term oncological outcome, postoperative complications should be minimized as much as possible.

Identification of ALDH3A2 as a novel prognostic biomarker in gastric adenocarcinoma using integrated bioinformatics analysis

BackgroundExtensive research has revealed that genes play a pivotal role in tumor development and growth. However, the underlying involvement of gene expression in gastric carcinoma (GC) remains to be investigated further.MethodsIn this study, we identified overlapping differentially expressed genes (DEGs) by comparing tumor tissue with adjacent normal tissue using the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) database.ResultsOur analysis identified 79 up-regulated and ten down-regulated genes. Functional enrichment analysis and prognosis analysis were conducted on the identified genes, and the fatty aldehyde dehydrogenase (FALDH) gene, ALDH3A2, was chosen for more detailed analysis. We performed Gene Set Enrichment Analysis (GSEA) and immunocorrelation analysis (infiltration, copy number alterations, and checkpoints) to elucidate the mechanisms of action of ALDH3A2 in depth. The immunohistochemical (IHC) result based on 140 paraffin-embedded human GC samples indicated that ALDH3A2 was over-expressed in low-grade GC cases and the OS of patients with low expression of ALDH3A2 was significantly shorter than those with high ALDH3A2 expression. In vitro results indicated that the expression of ALDH3A2 was negatively correlated with PDCD1, PDCD1LG2, and CTLA-4.ConclusionWe conclude that ALDH3A2 might be useful as a potential reference value for the relief and immunotherapy of GC, and also as an independent predictive marker for the prognosis of GC.

Identification of a nine-gene prognostic signature for gastric carcinoma using integrated bioinformatics analyses.

BACKGROUNDGastric carcinoma (GC) is one of the most aggressive primary digestive cancers. It has unsatisfactory therapeutic outcomes and is difficult to diagnose early.AIMTo identify prognostic biomarkers for GC patients using comprehensive bioinformatics analyses.METHODSDifferentially expressed genes (DEGs) were screened using gene expression data from The Cancer Genome Atlas and Gene Expression Omnibus databases for GC. Overlapping DEGs were analyzed using univariate and multivariate Cox regression analyses. A risk score model was then constructed and its prognostic value was validated utilizing an independent Gene Expression Omnibus dataset (GSE15459). Multiple databases were used to analyze each gene in the risk score model. High-risk score-associated pathways and therapeutic small molecule drugs were analyzed and predicted, respectively.RESULTSA total of 95 overlapping DEGs were found and a nine-gene signature (COL8A1, CTHRC1, COL5A2, AADAC, MAMDC2, SERPINE1, MAOA, COL1A2, and FNDC1) was constructed for the GC prognosis prediction. Receiver operating characteristic curve performance in the training dataset (The Cancer Genome Atlas-stomach adenocarcinoma) and validation dataset (GSE15459) demonstrated a robust prognostic value of the risk score model. Multiple database analyses for each gene provided evidence to further understand the nine-gene signature. Gene set enrichment analysis showed that the high-risk group was enriched in multiple cancer-related pathways. Moreover, several new small molecule drugs for potential treatment of GC were identified.CONCLUSIONThe nine-gene signature-derived risk score allows to predict GC prognosis and might prove useful for guiding therapeutic strategies for GC patients.

Gastric Carcinoma in Young Patients and Its Clinicopathological Characteristics and Prognosis.

Background Gastric cancer is usually an age-related disease and mostly diagnosed after the sixth decade of life, though it may also be diagnosed earlier. Objective The aim of this study is to explore the clinicopathological characteristics and prognosis of gastric carcinoma in young patients. Methods A total of 1379 patients younger than 75 years histologically diagnosed with primary gastric carcinoma underwent gastrectomy. Patients were categorized into three groups based on their age which included young age group (≤40 years), middle-aged group (age 41-60 years), and elderly group (age 61-75 years). The young age group was further subdivided into two groups: Group A (age ≤35 years) and Group B (age 35-40 years). The analysis of the clinicopathological characteristics and prognosis followed thereafter. Results Females predominate in young group (p < 0.001). A significantly higher undifferentiated histological pattern was found in the young age group from the other two groups (p < 0.001). Tumor location in the lower third of the stomach was significantly higher in the young group than the other groups (p < 0.001). T4 stage was common in young patients similar to the middle and old age group (p = 0.049). Distal gastrectomy was performed more in the young age group rather than the middle and old age groups with the following percentage ratios: young group 74.5% (123/165), middle age group 59.9% (429/716), and old age group 52.2% (260/498) (p < 0.001). The 5-year overall survival rate of the young, middle, and old age groups were 46%, 48%, and 39%, respectively, whereas the 5-year overall survival rates of the subgroups of young patients, Group A and Group B, were 33% and 49%, respectively. Multivariate analysis revealed that independent negative prognostic factors were as follows: tumor location (L), p = 0.016, OR = 0.795, 95%CI = [0.659; 0.959]; larger tumor size, p = 0.026, OR = 1.727, 95%CI = [1.067; 2.797]; resection margin, p < 0.001, OR = 2.167, 95%CI = [1.751; 2.682]; tumor stage (T4), p < 0.001, OR = 2.572, 95%CI = [1.709; 3.870]; and nodal involvement N1, p = 0.005, OR = 1.506, 95%CI = [1.123; 2.020]; N2, p < 0.001, OR = 1.708, 95%CI = [1.289; 2.263]; and N3, p < 0.001, OR = 2.986, 95%CI = [2.314; 3.854]. Conclusion The young age groups of patients were predominantly female and had a higher proportion of poorly differentiated and undifferentiated type of tumor; moreover, patients aged <35 years had a poor prognosis. In addition, gastric cancer can occur in patients less than 30 years old, and symptoms suggestive of gastric cancer should be investigated aggressively; therefore, a close scrutiny and monitoring should be done in younger patients especially those associated with high-risk factors which could indicate the presence of the disease at an early stage.

ARMCX Family Gene Expression Analysis and Potential Prognostic Biomarkers for Prediction of Clinical Outcome in Patients with Gastric Carcinoma.

Armadillo gene subfamily members (ARMCX1-6) are well-known to regulate protein-protein interaction involved in nuclear transport, cellular connection, and transcription activation. Moreover, ARMCX signals on cell pathways also implicated in carcinogenesis and tumor progression. However, little is known about the associations of the ARMCX subfamily members with gastric carcinoma. This study investigated the prognostic value of ARMCX subfamily mRNA expression levels with the prognosis of gastric carcinoma (GC). We retrieved the data of a total of 351 GC patients from TCGA database. Survival and gene set enrichment analyses were employed to explore the predictive value and underlying mechanism of ARMCX genes in GC. The multivariate survival analysis revealed that individually low expressions of ARMCX1 (adjusted P = 0.006, HR = 0.620, CI = 0.440 − 0.874) and ARMCX2 (adjusted P = 0.005, HR = 0.610, 95%CI = 0.432–0.861) were related to preferable overall survival (OS). The joint-effects analysis shown that combinations of low level expression of ARMCX1 and ARMCX2 were correlated with favorable OS (adjusted P = 0.003, HR = 0.563, 95%CI = 0.384–0.825). ARMCX1 and ARMCX2 were implicated in WNT and NF-kappaB pathways, and biological processes including cell cycle, apoptosis, RNA modification, DNA replication, and damage response. Our results suggest that mRNA expression levels of ARMCX subfamily are potential prognostic markers of GC.

Mining the role of RECQL5 in gastric cancer and seeking potential regulatory network by bioinformatics analysis

AimThe role of RecQ protein-like 5 (RECQL5) in gastric carcinoma (GC) is still unclear. Here, we investigated the role of RECQL5 in human GC and its potential regulatory network via bioinformatics analysis. MethodsBioinformatic analysis was performed using data in the Oncomine database, Kaplan- Meier Plotter online software, MethHC database, catalogue of somatic mutations in cancer (COSMIC), cbioportal database and String database. Then, we verified the association between RECQL5 expression and GC prognosis by immunohistochemistry (IHC). The independent prognostic factors were determined by Cox multivariate analysis. ResultsIt was found that both the mRNA and protein expression levels of RECQL5 were downregulated in GC samples (P < .05). Low RECQL5 expression indicated a poor prognosis in GC patients and is the independent prognostic factors for GC. No correlation between RECQL5 mRNA and DNA methylation was found using the MethHC database. The analysis of the COSMIC database showed a high proportion of missense mutation in GC. The functional enrichment analysis predicted that RECQL5 plays a role in DNA repair and cellular responses to DNA damage stimulus. RECQL5 might be enriched in homologous recombination pathways and Fanconi anemia pathway. Bioinformatics analysis identified 5 genes, namely POLR2D, POLR2G, DXO, KIN, and EIF2D, that were significantly correlated with RECQL5. ConclusionThe low expression of RECQL5 predicts poor overall survival in GC. RECQL5 may be a novel tumor suppressor for patients with GC.

Disadvantages for non-Hispanic whites in gastric carcinoma survival in Florida.

The prognosis for gastric carcinoma (GC) remains challenging with less than 35% of patients surviving 5years. GC survival varies greatly by anatomical site, cardia and non-cardia. However, these important differences have not been thoroughly studied in relation to the increasing diversity in US populations such as Florida. In this study we examined, for the first time, the effect of race-ethnicity on risk of death from GC controlling for potential risk factors separately for cardia and non-cardia GCs. Data on GCs diagnosed in Florida from 2005-2016 were obtained from the statewide cancer registry. Age-standardized GC-specific 5-year survival was computed by anatomical site and race-ethnicity. In addition, a competing risk analysis was performed to assess prognostic factors and to estimate subdistribution hazard ratios of death from GC. Whites had high proportions of cardia GC (43.9%) compared to all racial/ethnic minorities (10.9%, 19.6%, and 13.8% in Blacks, Hispanics, and Asians, respectively; p < .0001). Among 12,302 cases included, there were 7534 deaths from GC and 1179 from other causes. Age standardized GC-specific 5-year survival was significantly lower for Whites (28.0%) compared to Blacks (31.6%), Hispanics (37.6%), and Asians, (39.6%) and significantly lower for cardia GC (25.0%, 95% CI 23.4-26.6) compared to non-cardia GC (37.0%, 95% CI 35.5-38.4). Multivariable competing risk analysis in patients with non-cardia GC showed that Asians (sHR: 0.64, 95% CI 0.51-0.80), Hispanics (sHR 0.71, 95% CI 0.64-0.78), and Blacks (sHR 0.83, 95% CI 0.75-0.92) all had lower risks of death from GC compared to Whites. In patients with cardia GC, only Hispanics had statistically significant lower risk of death from GC than Whites (sHR 0.84, 95% CI 0.74-0.95, p = 0.005). The study of racial/ethnic survival disparities in patients with GC in Florida reveals Whites as the most disadvantaged group. Whites are more afflicted by cardia GC, which is associated with higher risk of death than non-cardia GC. However, even within non-cardia GC, Whites had higher risk of death than the other racial-ethnic groups. Commonly assessed survival determinants do not adequately explain these unusual disparities; thus, further investigation is warranted.

A transcriptional co-expression network-based approach to identify prognostic biomarkers in gastric carcinoma.

BackgroundGastric carcinoma is a very diverse disease. The progression of gastric carcinoma is influenced by complicated gene networks. This study aims to investigate the actual and potential prognostic biomarkers related to survival in gastric carcinoma patients to further our understanding of tumor biology.MethodsA weighted gene co-expression network analysis was performed with a transcriptome dataset to identify networks and hub genes relevant to gastric carcinoma prognosis. Data was obtained from 300 primary gastric carcinomas (GSE62254). A validation dataset (GSE34942 and GSE15459) and TCGA dataset confirmed the results. Gene ontology, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and gene set enrichment analysis (GSEA) were performed to identify the clusters responsible for the biological processes and pathways of this disease.ResultsA brown transcriptional module enriched in the organizational process of the extracellular matrix was significantly correlated with overall survival (HR = 1.586, p = 0.005, 95% CI [1.149–2.189]) and disease-free survival (HR = 1.544, p = 0.008, 95% CI [1.119–2.131]). These observations were confirmed in the validation dataset (HR = 1.664, p = 0.006, 95% CI [1.155–2.398] in overall survival). Ten hub genes were identified and confirmed in the validation dataset from this brown module; five key biomarkers (COL8A1, FRMD6, TIMP2, CNRIP1 and GPR124 (ADGRA2)) were identified for further research in microsatellite instability (MSI) and epithelial-tomesenchymal transition (MSS/EMT) gastric carcinoma molecular subtypes. A high expression of these genes indicated a poor prognosis.ConclusionA transcriptional co-expression network-based approach was used to identify prognostic biomarkers in gastric carcinoma. This method may have potential for use in personalized therapies, however, large-scale randomized controlled clinical trials and replication experiments are needed before these key biomarkers can be applied clinically.

Serum miR-191 and miR-425 as Diagnostic and Prognostic Markers of Advanced Gastric Cancer Can Predict the Sensitivity of FOLFOX Chemotherapy Regimen.

PurposemiR-191 and miR-425 have been proved to be highly expressed in gastric carcinoma (GC). However, little research has been done on their clinical value in serum of patients with advanced GC. In addition, it is not clear whether they can be used as markers for the response and prognosis of GC patients treated with oxaliplatin combined with 5-fluorouracil and FOLFOX chemotherapy.Patients and MethodsA total of 230 patients with advanced GC admitted to our hospital were selected as the study objects, all of whom received FOLFOX chemotherapy regimen. Another 100 cases of healthy subjects were included. QRT-PCR was employed to detect the serum expression of miR-191 and miR-425 in patients.ResultsCompared with the healthy subjects, the serum expressions of miR-191 and miR-425 in GC patients were significantly upregulated, which were correlated with differentiation degree and TNM staging, respectively. According to the ROC curve, the AUC of miR-191 and miR-425 for GC diagnosis was 0.937 and 0.901, respectively, while the AUC for differentiation degree diagnosis was 0.854 and 0.822, and that for TNM staging diagnosis was 0.860 and 0.829, respectively. The predictive AUC of miR-191 and miR-425 for chemosensitivity was 0.868 and 0.835, respectively, with a combined predictive AUC of 0.935. Low differentiation degree, high TNM staging, high miR-191 and high miR-425 expressions were independent risk factors for chemotherapy insensitivity. Differentiation degree, TNM staging, chemotherapy effect, miR-191 and miR-425 were independent influencing factors for the prognosis of GC patients.ConclusionUp-regulated expression of miR-191 and miR-425 in the serum of patients with advanced GC are effective biomarkers for the diagnosis, chemotherapy and prognosis evaluation of GC.

TRFs as Potential Exosome tRNA-Derived Fragment Biomarkers for Gastric Carcinoma.

Gastric Carcinoma (GC) is one of the common diseases induced by the interaction of genes and environment. Exosomes are potential markers for several health problems, which contain lipids, proteins, long non-coding RNAs, microRNAs (miRNAs), and tRNA-derived fragments (tRFs). The roles of mRNAs and miRNAs in GC have been studied comprehensively; however, little research was focused on the function of plasma exosomal tRFs. We collected plasma samples from fifty healthy controls and fifty GC patients, and all exosomes were isolated with a combined centrifugation and characterized by electron microscopy, western blot, and flow cytometry. The small RNA sequence was performed to detect the plasma exosomal tRFs, and tRFs markers were validated by real-time quantitative PCR. Three exosomal diagnostic tRFs were confirmed by receiver operating characteristic analyses. In this study, we found higher plasma exosomal tRF-25, tRF-38, tRF-18 expression in GC than in controls. Plasma exosomal tRF-25, tRF-38, and tRF-18 showed better accuracy for GC diagnosis. Our results suggest that plasma exosomal tRF-25, tRF-38, and tRF-18 were biomarkers for GC detection; tRF-25, tRF-38 and tRF-18 might be predictive of GC prognosis.

Oct4 expression in gastric carcinoma: association with tumor proliferation, angiogenesis and survival

BackgroundOctamer-binding transcription factor 4 (Oct4) is a transcription factor that has an important role in stem cell differentiation and self-renewal. Oct4 has also been implicated in tumorigenicity of different cancers. This study aimed to analyze Oct4 expression in gastric carcinoma (GC) and to evaluate the relation between Oct4 expression and clinicopathologic parameters, tumor proliferation, and angiogenesis in addition to patient survival.ResultsOct4 mRNA was detected by quantitative reverse transcription PCR (qRT-PCR) in 45 GC specimens and adjacent non-cancerous tissues. We found a significant difference in Oct4 mRNA relative expression levels in GC tissue compared with adjacent non-cancerous tissues (p < 0.001). Furthermore, immunohistochemistry (IHC) was performed to study the Oct4 expression in GC cases. High Oct4 immunostaining was detected in 62.2% of GC specimens. High Oct4 expression both by mRNA relative quantitation and IHC were significantly related to poorly differentiated tumors, nodal metastasis, and stage III tumors. Moreover, high Oct4 IHC expression was also associated with cases positive for Ki-67 and VEGF expressions (p < 0.001 and 0.021, respectively). Oct4 expression identified by both mRNA relative quantitation and IHC was significantly related (p < 0.001). As regards patient survival, high Oct4 expression was significantly related to poor overall survival (OS) and disease-free survival (DFS) (p = 0.029 and 0.031, respectively).ConclusionOct4 plays a valuable role in the progression and prognosis of GC. High Oct4 expression is associated with high tumor grade, nodal metastasis, stage III tumors, and poor OS and DFS. High Oct4 is also significantly associated with Ki-67 and VGEF expression, thus enhancing tumor proliferation and angiogenesis.

LncRNA LOXL1-AS1 facilitates the tumorigenesis and stemness of gastric carcinoma via regulation of miR-708-5p/USF1 pathway.

ObjectivesAs one of the most life‐threatening malignancies, gastric cancer is the third contributor of cancer mortalities globally. Increasing studies have proven the regulatory roles of lncRNAs in the development of diverse malignant tumours. But little is known about its function and molecular mechanism in gastric carcinoma.Materials and methodsRT‐qPCR was performed to measure the expression pattern of LOXL1‐AS1 in gastric cancer. To ascertain its definite role, CCK‐8, EdU, Western blot, transwell and sphere formation assays were adopted. RNA pull‐down, RIP, ChIP and luciferase reporter assays were carried out to investigate the molecular mechanism of LOXL1‐AS1 in gastric carcinoma.ResultsLOXL1‐AS1 was highly expressed in tissues and cells of gastric cancer. The upregulation of LOXL1‐AS1 predicted poor prognosis in gastric carcinoma. Our findings demonstrated that LOXL1‐AS1 accelerated the deterioration of gastric cancer by inducing cell proliferation, migration, EMT and stemness. Moreover, the expression of USF1 in gastric cancer was higher than in normal control and LOXL1‐AS1 negatively modulated USF1. Functionally, LOXL1‐AS1 acted as a ceRNA to upregulate USF1 via sponging miR‐708‐5p. Besides, we confirmed USF1 promoted the transcription of stemness marker SOX2. Rescue experiments testified the stimulative role of LOXL1‐AS1/miR‐708‐5p/USF1 pathway in gastric cancer progression. It was also validated that LOXL1‐AS1 facilitated cell growth of gastric carcinoma in vivo.ConclusionsOur study unravelled that LOXL1‐AS1/miR‐708‐5p/USF1 pathway contributed to the development of gastric cancer.

MiR-92a antagonized the facilitation effect of extracellular matrix protein 1 in GC metastasis through targeting its 3′UTR region

MicroRNAs were known to play very important roles in human diseases, and have attracted great interests of research scientists in medicine, toxicology and functional foods. Gastric carcinoma (GC) remains one of the most common and lethal types of malignancy worldwide. However, the molecular mechanism of GC and the role of microRNAs in GC development remain unclear. The expression of extracellular matrix protein 1 (ECM1) is up-regulated in many cancer types, but its functional role is inconstant. In the present study, we aimed to investigate the correlation between GC development and ECM1 expression, along with its regulation by microRNAs. Immunohistochemical results showed that ECM1 was up-regulated in GC tissues and ECM1 expression level was negatively correlated with the prognosis of GC. ECM1 was found to promote gastric cancer cell metastasis in cell migration assays by facilitating the expression of proteins involved in epithelial-mesenchymal transition (EMT). MiR-92a was recognized for the first time to suppress the migration of human GC cells by directly targeting to the 3′UTR of ECM1 gene in a dual-luciferase reporter assay. These results highlighted the antagonistic roles of ECM1 and miR-92a in GC development, which may serve as a new target for gastric cancer.

High expression of MRE11 correlates with poor prognosis in gastric carcinoma

BackgroundMRE11, a protein known to play a vital role in DNA double-strand break repair, is associated with the prognosis of a variety of tumours, but there are few studies regarding the role of MRE11 in gastric carcinoma (GC). The present study aimed to explore the clinicopathological significance and prognostic value of MRE11 expression in GC.MethodsData from the TCGA, GEO and Oncomine databases were analysed to assess MRE11 mRNA levels in GC. The prognostic role of the level of MRE11 mRNA was examined via the Kaplan-Meier plotter. MRE11 protein expression in tumour tissues from 155 GC patients was analysed by immunohistochemistry. Relationships between MRE11 expression and clinicopathological characteristics, overall survival (OS) and recurrence-free survival (RFS) were evaluated by Cox proportional hazards regression models and Kaplan-Meier survival curves.ResultsThe results of bioinformatics analysis showed that MRE11 mRNA levels in GC tissues were higher than those in normal tissues (P < 0.01). Tissue microarray analysis showed that MRE11 protein expression was increased in GC tissues (P < 0.001), and MRE11 overexpression in GC tissues was significantly related to lymph node metastasis (P < 0.05), distant metastasis (P < 0.05) and tumour-node-metastasis stage (P < 0.05). Kaplan-Meier analyses showed that patients with GC who exhibited MRE11 overexpression had worse OS and RFS. According to Cox proportional hazards analyses, MRE11 overexpression was an independent prognostic factor for OS and RFS in these GC patients.ConclusionsMRE11 overexpression is significantly associated with poor prognosis, and MRE11 may serve as a prognostic biomarker in GC patients.

Effects of microRNA-378 on epithelial-mesenchymal transition, migration, invasion and prognosis in gastric carcinoma by targeting BMP2.

Gastric cancer (GC) is a common malignancy. Recent studies have suggested that microRNAs are crucial factors in tumorigenesis. Thus, we investigated the effect of miR-378 on GC metastasis and further explored the underlying mechanism. Quantitative Real-time polymerase chain reaction (qRT-PCR) was carried out to measure the miR-378 expressions in GC and adjacent normal tissue samples. MiR-378 expressions in human GC cells were determined using qRT-PCR and Western blots. Moreover, transwell assays were conducted to measure the invasion and migration capacities of GC cells. Additionally, the regulating effects on BMP2 by miR-378 were assessed by luciferase reporter assays and western blots. Western blot was also carried out to observe the protein expressions of epithelial-mesenchymal transition (EMT) related genes. MiR-378 expressions in GC tissues were downregulated. In the meantime, reduced miR-378 expression was associated with poor prognosis and malignant clinicopathologic features of GC patients. MiR-378 overexpression repressed GC cell invasion, migration and EMT. Furthermore, BMP2 was a direct target of miR-378 and implicated in miR-378-mediated suppressive functions in GC invasion, migration and EMT. We showed that miR-378 served as a tumor suppressor in GC via modulating BMP2, suggesting that miR-378/BMP2 axis might be therapeutic targets and promising biomarkers for GC treatment.