Diagnostic Marker For Gastric Cancer Research Articles

Genome-wide 5-hydroxymethylcytosines in circulating cell-free DNA as noninvasive diagnostic markers for gastric cancer.

5-Hydroxymethylcytosine-enriched gene profiles and regions show tissue-specific and tumor specific. There is a potential value to explore cell-free DNA 5-hydroxymethylcytosine feature biomarkers for early gastric cancer detection. A matched case‒control study design with 50 gastric cancer patients and 50 controls was performed to sequence the different 5-hydroxymethylcytosine modification features of cell free DNA. Significantly differential 5-hydroxymethylcytosine modification genes were identified to construct a gastric cancer diagnostic model. Data set from GEO was used as an external testing set to test the robustness of the diagnostic model. Accounting for more than 90% of 5-hydroxymethylcytosine peaks were distributed in the gene body in both the gastric cancer and control groups. The diagnostic model was developed based on five different 5-hydroxymethylcytosine modification genes, FBXL7, PDE3A, TPO, SNTG2 and STXBP5. The model could effectively distinguish gastric cancer patients from controls in the training (AUC = 0.95, sensitivity = 88.6%, specificity = 94.3%), validation (AUC = 0.87, sensitivity = 73.3%, specificity = 93.3%) and testing (AUC = 0.90, sensitivity = 81.9%, specificity = 90.2%) sets. The risk scores of the controls from the model were significantly lower than those of gastric cancer patients in bothour own data (P < 0.001) and GEO external testing data (P < 0.001), and no significant difference between different TNM stage patients (P = 0.09 and 0.66). Furthermore, there was no significant difference between the healthy control and benign gastric disease patients in the testing set from GEO (P = 0.10). The characteristics of 5-hydroxymethylcytosine in cell free DNA are specific to gastric cancer patients, and the diagnostic model constructed by five genes' 5-hydroxymethylcytosine features could effectively identify gastric cancer patients.

Predicting early gastric cancer risk using machine learning: A population-based retrospective study.

Early detection and treatment are crucial for reducing gastrointestinal tumour-related mortality. The diagnostic efficiency of the most commonly used diagnostic markers for gastric cancer (GC) is not very high. A single laboratory test cannot meet the requirements of early screening, and machine learning methods are needed to aid the early diagnosis of GC by combining multiple indicators. Based on the XGBoost algorithm, a new model was developed to distinguish between GC and precancerous lesions in newly admitted patients between 2018 and 2023 using multiple laboratory tests. We evaluated the ability of the prediction score derived from this model to predict early GC. In addition, we investigated the efficacy of the model in correctly screening for GC given negative protein tumour marker results. The XHGC20 model constructed using the XGBoost algorithm could distinguish GC from precancerous disease well (area under the receiver operating characteristic curve [AUC] = 0.901), with a sensitivity, specificity and cut-off value of 0.830, 0.806 and 0.265, respectively. The prediction score was very effective in the diagnosis of early GC. When the cut-off value was 0.27, and the AUC was 0.888, the sensitivity and specificity were 0.797 and 0.807, respectively. The model was also effective at evaluating GC given negative conventional markers (AUC = 0.970), with the sensitivity and specificity of 0.941 and 0.906, respectively, which helped to reduce the rate of missed diagnoses. The XHGC20 model established by the XGBoost algorithm integrates information from 20 clinical laboratory tests and can aid in the early screening of GC, providing a useful new method for auxiliary laboratory diagnosis.

Cell-free Nucleic Acid as Promising Diagnostic Biomarkers for Gastric Cancer: a Systematic Review.

Background: Gastric cancer (GC) is a common malignancy with early detection being crucial for survival. Liquid biopsy analysis using cell-free nucleic acid is a preferred method for detection. Hence, we conducted a systematic review to assess the diagnostic efficacy of cell-free nucleic acid markers for GC. Methods: We searched PubMed and ISI Web of Science databases for articles that conformed to our inclusion and exclusion criteria from 2012 to 2022. The following information was abstracted: first author, year of publication, country/region, age, male proportion, tumor stage for cases, specimen type, measurement method, targeted markers and diagnostic related indicators (including sensitivity, specificity, AUC, P-value). Results: Fifty-eight studies examined cell-free RNAs (cfRNAs) with a total of 62 individual circulating markers and 7 panels in serum or plasma, while 21 studies evaluated cell-free DNAs (cfDNAs) with 29 individual circulating markers and 7 panels. For individual cfRNAs, the median (range) sensitivity and specificity were 80% (21% - 98%) and 80% (54% - 99%), respectively. The median (range) sensitivity and specificity for cfRNA panels were 86% (83% - 90%) and 75% (60% - 98%), respectively. In comparison, the median (range) sensitivity and specificity reported for individual cfDNAs were 50% (18% - 96%) and 93% (57% - 100%), respectively, while cfDNA panels had a median (range) sensitivity and specificity of 85% (41% - 92%) and 73.5% (38% - 90%), respectively. The meta results indicate that cfRNA markers exhibit high sensitivity (80%) and low specificity (80%) for detecting GC, while cfDNA markers have lower sensitivity (59%) but higher specificity (92%). Conclusions: This review has demonstrated that cell-free nucleic acids have the potential to serve as useful diagnostic markers for GC. Given that both cfRNA and cfDNA markers have shown promising diagnostic performance for GC, the combination of the two may potentially enhance diagnostic efficiency.

Soluble HLA-G (sHLA-G) measurement might be useful as an early diagnostic biomarker and screening test for gastric cancer

Gastric cancer (GC) is the fifth most frequent malignancy worldwide and has a high mortality rate related to late diagnosis. Although the gold standard for the GC diagnosis is endoscopy with biopsy, nonetheless, it is not cost-effective and is invasive for the patient. The Human leukocyte antigen G (HLA-G) molecule is a checkpoint of the immune response. Its overexpression in cancer is associated with immune evasion, metastasis, poor prognosis, and lower overall survival. We evaluate the plasma levels of soluble HLA-G, (sHLA-G) in patients with GC and benign gastric pathologies using an ELISA test. A higher concentration of sHLA-G in patients with GC than in those with benign pathologies, higher levels of plasma sHLA-G in women with GC compared with men and significant differences in the sHLA-G levels between the benign gastric pathologies evaluated, was our main findings. As no significant differences were found between the GC assessed stages in our study population, we suggest that sHLA-G is not an adequate marker for staging GC, but it does have diagnostic potential. In addition to providing information on the potential of sHLA-G as a diagnostic marker for GC, our study demonstrate that HLA-G molecules can be found in the membrane of exosomes, which highlights the need to perform studies with a larger number of samples to explore the functional implications of HLA-G positive exosomes in the context of gastric cancer, and to determine the clinical significance and possible applications of these findings in the development of non-invasive diagnostic methods.

Single and combined use of the platelet-lymphocyte ratio, neutrophil-lymphocyte ratio, and systemic immune-inflammation index in gastric cancer diagnosis.

The platelet-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR), and systemic immune-inflammation index (SII) are markers for systemic inflammatory responses and have been shown by numerous studies to correlate with the prognosis of gastric cancer (GC). However, the diagnostic value of these three markers in GC is unclear, and no research has examined them in combination. In this study, we investigated the value of the PLR, NLR, and SII individually or in combination for GC diagnosis and elucidated the connection of these three markers with GC patients' clinicopathological features. This retrospective study was conducted on 125 patients diagnosed with GC and 125 healthy individuals, whose peripheral blood samples were obtained for analysis. The preoperative PLR, NLR, and SII values were subsequently calculated. The results suggest that the PLR, NLR, and SII values of the GC group were considerably higher than those of the healthy group (all P ≤ 0.001); moreover, all three parameters were notably higher in early GC patients (stage I/II) than in the healthy population. The diagnostic value of each index for GC was analyzed using receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) calculation. The diagnostic efficacy of the SII alone (AUC: 0.831; 95% confidence interval [CI], 0.777-0.885) was expressively better than those of the NLR (AUC: 0.821; 95% CI: 0.769-0.873, P = 0.017) and PLR (AUC: 0.783; 95% CI: 0.726-0.840; P = 0.020). The AUC value of the combination of the PLR, NLR, and SII (AUC: 0.843; 95% CI: 0.791-0.885) was significantly higher than that of the combination of the SII and NLR (0.837, 95% CI: 0.785-0.880, P≤0.05), PLR (P = 0.020), NLR (P = 0.017), or SII alone (P ≤ 0.001). The optimal cut-off values were determined for the PLR, NLR, and SII using ROC analysis (SII: 438.7; NLR: 2.1; PLR: 139.5). Additionally, the PLR, NLR, and SII values were all meaningfully connected with the tumor size, TNM stage, lymph node metastasis, and serosa invasion (all P ≤ 0.05). Elevated levels of the NLR and SII were linked to distant metastasis (all P ≤ 0.001). These data suggest that the preoperative PLR, NLR, and SII could thus be utilized as diagnostic markers for GC or even early GC. Among these three indicators, the SII had the best diagnostic efficacy for GC, and the combination of the three could further improve diagnostic efficiency.

Circ_0000467 regulates proliferation, migration, invasion, and apoptosis in gastric cancer by targeting the miR-622/ROCK2 axis.

Gastric cancer (GC) ranks fourth as a cause of cancer-induced mortality worldwide. Recently, some studies have demonstrated that circular RNAs (circRNAs) play vital roles in human cancers, including GC. The expression levels of circ_0000467, microRNA-622 (miR-622), and Rho-associated coiled-coil-containing protein kinase2 (ROCK2) were determined by RT-qPCR assay. The protein expression was quantified by western blot assay. The interaction relationship between miR-622 and circ_0000467 or ROCK2 was confirmed by dual-luciferase reporter assay and RIP assay. The biological behaviors of GC cells including proliferation, apoptosis, migration, and invasion were determined by EdU assay, colony-forming assay, flow cytometry, and transwell assay. The effects of circ_0000467 silencing in vivo were assessed by a xenograft experiment in nude mice. MiR-622 was downregulated and ROCK2 was upregulated in GC tissues and cells. Loss-of-function experiment revealed that overexpression of miR-622 decreased proliferation, migration, and invasion while it increased apoptosis in GC cells. Furthermore, ROCK2 was a functional target of miR-622, and upregulation of ROCK2 abolished miR-622-induced effects on GC cells. What's more, circ_0000467 was upregulated in GC, and inhibition of miR-622 reversed silencing of circ_0000467-caused effects on GC cells, suggesting that miR-622 was a target of circ_0000467. The suppression of circ_0000467 was able to slow the tumor growth in vivo. Mechanistically, circ_0000467 functioned as an oncogenic regulator in GC by specifically binding to miR-622 to upregulate ROCK2, which might be novel diagnostic markers for GC.

Identification of the diagnostic genes and immune cell infiltration characteristics of gastric cancer using bioinformatics analysis and machine learning.

Background: Finding reliable diagnostic markers for gastric cancer (GC) is important. This work uses machine learning (ML) to identify GC diagnostic genes and investigate their connection with immune cell infiltration. Methods: We downloaded eight GC-related datasets from GEO, TCGA, and GTEx. GSE13911, GSE15459, GSE19826, GSE54129, and GSE79973 were used as the training set, GSE66229 as the validation set A, and TCGA & GTEx as the validation set B. First, the training set screened differentially expressed genes (DEGs), and gene ontology (GO), kyoto encyclopedia of genes and genomes (KEGG), disease Ontology (DO), and gene set enrichment analysis (GSEA) analyses were performed. Then, the candidate diagnostic genes were screened by LASSO and SVM-RFE algorithms, and receiver operating characteristic (ROC) curves evaluated the diagnostic efficacy. Then, the infiltration characteristics of immune cells in GC samples were analyzed by CIBERSORT, and correlation analysis was performed. Finally, mutation and survival analyses were performed for diagnostic genes. Results: We found 207 up-regulated genes and 349 down-regulated genes among 556 DEGs. gene ontology analysis significantly enriched 413 functional annotations, including 310 biological processes, 23 cellular components, and 80 molecular functions. Six of these biological processes are closely related to immunity. KEGG analysis significantly enriched 11 signaling pathways. 244 diseases were closely related to Ontology analysis. Multiple entries of the gene set enrichment analysis analysis were closely related to immunity. Machine learning screened eight candidate diagnostic genes and further validated them to identify ABCA8, COL4A1, FAP, LY6E, MAMDC2, and TMEM100 as diagnostic genes. Six diagnostic genes were mutated to some extent in GC. ABCA8, COL4A1, LY6E, MAMDC2, TMEM100 had prognostic value. Conclusion: We screened six diagnostic genes for gastric cancer through bioinformatic analysis and machine learning, which are intimately related to immune cell infiltration and have a definite prognostic value.

Exosomal miRNA Expression Profiling and the Roles of Exosomal miR-4741, miR-32, miR-3149, and miR-6727 on Gastric Cancer Progression.

Objective Accumulated evidence highlights the biological implications of exosomes in gastric cancer. Herein, we conducted the exosomal miRNA expression profiling and identified potential diagnostic markers for gastric cancer. Methods Plasma exosomes were isolated and identified from three gastric cancer patients and three healthy participants. Microarrays of exosomal miRNAs were then analyzed. Differentially expressed exosomal miRNAs were screened with fold − change|≥2.0 and p ≤ 0.05. Among them, miR-4741, miR-32, miR-3149, and miR-6727 expressions were verified in tissues and plasma of patients and healthy subjects. ROC curves were conducted for evaluating the diagnostic performance. The roles of miR-32, miR-3149, miR-6727, and miR-4741 on gastric cancer progression were observed by cellular experiments. Results Isolated exosomes were well characterized by Western blot and transmission electron microscopy as well as nanoparticle-tracking analyses. According to the microarrays, 142 exosomal miRNAs were upregulated, and 34 were downregulated in gastric cancer than healthy subjects. miR-4741 upregulation and miR-32, miR-3149, and miR-6727 downregulations were found in tissues and plasma of gastric cancer patients. The AUCs of miR-4741, miR-32, miR-3149, and miR-6727 were separately 0.8554, 0.9456, 0.7683, and 0.8923. Upregulated miR-32, miR-3149, and miR-6727 as well as downregulated miR-4741 lowered proliferative, migratory, and invasive capacities as well as elevated apoptotic levels of gastric cancer cells. Conclusion Our study successfully isolated and verified exosomes from plasma of gastric cancer as well as proposed four exosomal miRNAs that could act as promising diagnostic markers and suppress gastric cancer progression.

Validity of Check Point Inhibitor (PD-1 and PD-L1) in Diagnosis of Gastric Adenocarcinoma Using Modified Tissue Elisa

Background: Checkpoint inhibitors (PD-1, PD-L1) are revolutionizing the oncology disease management process. Despite the fact that gastric cancer is a common malignancy with a poor prognosis, relatively little attention has been drawn and attracted to the treatment and diagnosis of this disease by using checkpoint inhibitor. James P. Allison and Tasuku Honjo were awarded the the Nobel Prize in Physiology and Medicine for their developments in fundamental science enabling checkpoint inhibitor therapies. Checkpoint inhibitor overexpression has been related to gastric cancer progression and clues for developing therapeutic goals as well as may provide diagnostic markers for gastric cancer. Aims: The aims of this study are firstly to detection of Checkpoint Inhibitors (PD-1, PD-L1) as novel diagnostics and prognostics markers first time in the world. Secondly, to investigate the validity of using (a modified tissue ELISA method) as a rapid, sensitive, low cost and specific diagnostic method in patients with gastric cancer. Patients and methods: Thirty gastric cancer patients were among patients who attending the Histopathology section -GIT hospital and Histopathology department- Teaching laboratories/ medical city teaching complex Baghdad / Ministry of Health, during the period from August 2020 to April 2021. Another 30 patients diagnosed with benign tumor, In addition, 30 apparently healthy people were chosen as a healthy control group. For these three groups, PD-1, PD-L1, using tissue ELISA technique was carried out. Results: The current study showed that the mean values of PD-1 in tissues of gastric cancer patients (133.413±53.126) was significantly higher (P=0.0001) in it in comparison to both benign tumor group (29.905±12.634) and control healthy group (21.775±12.489); for PD-L1 that the mean values of PD-L1 in tissues of gastric cancer patients (151.175±47.641) was significantly higher (P=0.0001) in it in comparison to both benign tumor group (72.565±9.945) and control healthy group (82.102±12.642); using receiver operating characteristic curve (ROC) area, which showed that area under the curve for PD-1 was (1.000) (p value 0.0001), while area under the curve for PDL-1 was (0.913) (p value 0.0001) and The cut off value for PD-1 associated with highest sensitivity and specificity (100%) was 40.2 ng/ml. The cut off value for PDL-1 associated with sensitivity (80%) and specificity (80%) was 51.6ng/ml. Conclusions: The present study showed that Checkpoint inhibitors (PD-1, PD-L1) values were significantly higher in patients affect with malignant gastric adenocarcinoma which may check a possible role of this marker in the progressing of the disease, furthermore the maximum sensitivity obtained from Checkpoint inhibitors (PD-1, PD-L1) was by using a cut off values equal to (40.2 ng/ml; 51.6 ng/ml) respectively. Therefore, Checkpoint inhibitors (PD-1, PD-L1) may be promising diagnostic tools especially at early stages and among patients at in promotion risk. Keywords: Checkpoint inhibitors (PD-1, PD-L1), gastric cancer.

CHREBP suppresses gastric cancer progression via the cyclin D1-Rb-E2F1 pathway

Accumulating evidence has demonstrated that carbohydrate response element binding protein (CHREBP) has a crucial function in tumor pathology. In this study, we found CHREBP downregulation in gastric cancer (GC) tissues, and CHREBP was determined to be an independent diagnostic marker of GC. The downregulation of CHREBP promoted cell proliferation and inhibited apoptosis. Moreover, the level of cyclin D1 was significantly correlated with CHREBP expression in GC and paracancerous normal samples. In addition, CHREBP transcriptionally inhibited cyclin D1 expression in GC cells. Tumor suppressor activity of CHREBP could be affected by the upregulation of cyclin D1. In summary, CHREBP was found to be an independent diagnostic marker of GC and to influence GC growth and apoptosis via targeting the cyclin D1-Rb-E2F1 pathway.

CircFCHO2 promotes gastric cancer progression by activating the JAK1/STAT3 pathway via sponging miR-194-5p

ABSTRACT circFCHO2 has been revealed to be overexpressed in gastric cancer (GC) patients. This article identified the function of circFCHO2 on GC progression. The expression of circFCHO2, miR-194-5p and JAK1 in 30 GC patients and cells was monitored by quantitative reverse transcription-polymerase chain reaction. circFCHO2 localization in GC cells was monitored by RNA fluorescence in situ hybridization. Cell counting kit-8 assay, 5-ethynyl-2-deoxyuridine staining, transwell experiment, tube formation and sphere formation experiments were applied to detect GC cell proliferation, invasion, angiogenesis and cancer stem cell characteristics. Dual-luciferase reporter gene assay, RNA pull down assay and RNA immunoprecipitation experiment were utilized to research the binding between two genes. In vivo tumorigenesis and lung metastasis were studied using nude mice. Immunohistochemistry and hematoxylin–eosin staining were conducted. Protein expression was assessed by Western blot. Serum exosomes of GC patients and healthy participants were isolated. circFCHO2 up-modulation in GC patients was related to poor outcome. circFCHO2 was located in the cytoplasm of GC cells. circFCHO2 silencing weakened the proliferation, invasion, angiogenesis and stem cell characteristics of GC cells. miR-194-5p knockdown counteracted this effect. circFCHO2 activated the JAK1/STAT3 pathway by sponging miR-194-5p. miR-194-5p overexpression attenuated the malignant phenotypes of GC cells. JAK1 overexpression abrogated this effect. circFCHO2 silencing weakened GC cells growth and lung metastasis in vivo. circFCHO2 was up-modulated in serum exosomes of GC patients. circFCHO2 was an oncogene in GC by activating the JAK1/STAT3 pathway via sponging miR-194-5p. circFCHO2 might be a novel target and diagnostic marker for GC.

Serum WT1-271 IgM antibody as a novel diagnostic marker for Gastric Cancer.

The Wilms tumor 1 gene, WT1, is overexpressed in various types of cancer, including gastric cancer. The product of WT1 is highly immunogenic and is a promising target molecule for cancer immunotherapy. The current study aimed to examine the production of WT1-specific IgG and IgM autoantibodies to identify biomarkers of diagnostic value in patients with gastric cancer. IgG antibodies that bind to WT1-derived peptides were obtained, the serum levels of which correlate with those of IgG antibodies against the WT1 protein in patients with intestinal malignancies. The serum levels of IgG and IgM antibodies against the WT1-271 peptide (271-288 amino acids) were examined in 39 healthy individuals and 97 patients with gastric cancer. The positivity cutoff value was determined according to the receiver operating characteristic curve. The association between WT1-271 IgM and the clinicopathological factors and prognosis of patients was additionally analyzed. The results revealed that serum WT1-271 IgM antibody levels in patients with gastric cancer were significantly higher than those in healthy individuals. The sensitivity and specificity of this antibody for gastric cancer were 67.0 and 71.8%, respectively; this sensitivity was improved when compared with conventional tumor markers (P<0.001). There was no statistical difference in WT1-271 IgG antibody levels between patients with gastric cancer and healthy individuals. Serum WT1-271 IgM antibody levels were not significantly associated with clinicopathological factors but were associated with unfavorable prognosis. Serum WT1-271 IgM antibody levels could serve as a diagnostic biomarker in patients with gastric cancer.

Nuclear staining of claudin-18 is a new immunohistochemical marker for diagnosing intramucosal well-differentiated gastric adenocarcinoma.

Diagnosis of gastric adenocarcinoma using small biopsy samples is occasionally difficult. Various markers have been employed for improving the diagnostic accuracy, but there remains room for improvement. A total of 129 endoscopically biopsied samples were studied, consisting of 104 intramucosal tubular adenocarcinomas, 24 non-cancerous lesions and one cancer sample originally suspected of non-cancer but revised as cancer after immunostaining. We evaluated the association between histopathology and immunohistochemical expression of MUC1, HER2, p53, CEA, E-cadherin, β-catenin and claudin-18. Regarding β-catenin and claudin-18, not only membranous expression (β-catenin(M) and claudin-18(M)) but also nuclear expression (β-catenin(N) and claudin-18(N)) were analyzed. When subtyped with mucin core protein expression, the gastric-type cancers dominantly expressed claudin-18(M), while claudin-18(N) was significantly encountered in intestinal- and mixed-types. Expression of MUC1 (P = 0.0010), HER2 (P = 0.0173), p53 (P = 0.0002), CEA (P = 0.0019) and claudin-18(N) (P < 0.0001) revealed significant correlation with gastric cancers. Negative correlation of claudin-18(M) (P = 0.0125) was also noted. MUC1 and p53 were negative in non-cancer lesions. The non-cancer group exceptionally expressed HER2 and β-catenin(N). Membranous expression of E-cadherin was consistent in both groups. Logistic regression analysis showed that MUC1 (P = 0.0086), p53 (P = 0.0031), claudin-18(M) (P = 0.0158) and claudin-18(N) (P = 0.0190) were independently associated with gastric cancers. Nuclear expression of claudin-18 should be the novel diagnostic marker for gastric cancer.

Circular RNA hsa_circRNA_102958 may serve as a diagnostic marker for gastric cancer.

Circular RNAs (circRNA) play key regulatory roles in cancer progression. Human circRNA microarray was performed to screen for abnormally expressed circRNA in gastric cancer tissues. In this study, we found circRNA102958 was up-regulated in gastric cancer tissues and cell lines. The hsa_circRNA_102958 levels were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in gastric tissue and cell. Then, the association between the expression level of hsa_circRNA_102958 and the clinicopathological features of patients with gastric cancer was further analyzed. Finally, a network of hsa_circRNA_102958-miRNA-mRNA interactions was predicated. In this study, we analyzed 30 patients and found that hsa_circRNA_102958 was significantly overexpressed in gastric cancer tissues compared with paired adjacent normal tissues. Clinicopathological features showed that hsa_circRNA_102958 level in GC tissues was positively associated with TNM stage (p= 0.032). The area under the ROC curve was 0.74. Finally, a total of 5 miRNAs were predicted to have an interaction with hsa_circRNA_102958. hsa_circRNA_102958 may be a potential novel and stable biomarker for the diagnosis of gastric carcinoma.

&lt;p&gt;Exosomal Long Non-Coding RNA CEBPA-AS1 Inhibits Tumor Apoptosis and Functions as a Non-Invasive Biomarker for Diagnosis of Gastric Cancer&lt;/p&gt;

AimTraditional non-invasive diagnostic markers for gastric cancer (GC) exhibit insufficient sensitivity and specificity. Circulating exosomes are clinically useful non-invasive biomarkers for tumor diagnosis. In addition to their potential role in cancer biology, circulating long non-coding RNAs (lncRNAs) are a new class of promising cancer biomarkers. In the present study, we aimed to identify lncRNAs in circulating exosomes with potential as biomarkers for GC detection.MethodsWe compared the expression of CEBPA-AS1 between GC cells and gastric epithelial cells. The biological function of exosomal CEBPA-AS1 was determined by cell phenotype experiments and rescue assays. We also compared the expression of CEBPA-AS1 in cancerous tissue from GC patients and corresponding adjacent normal tissues, as well as the expression of CEBPA-AS1 in plasma exosomes of GC patients and healthy controls. Diagnostic accuracy was assessed by the receiver operating characteristic (ROC) curve and area under the curve (AUC).ResultsCEBPA-AS1 was highly expressed in both GC cells and in exosomes secreted by GC cells. In addition, CEBPA-AS1-containing exosomes secreted by GC cells could promote cell proliferation and inhibit apoptosis, thereby inducing the malignant behavior of GC cells. The level of CEBPA-AS1 was also significantly increased in tissues and plasma exosomes of GC patients. Stability tests showed that most plasma CEBPA-AS1 was encased in exosomes, thus avoiding degradation by RNases. We evaluated the diagnostic accuracy of exosome-derived CEBPA-AS1. The AUC value of CEBPA-AS1 in discriminating GC patients from healthy controls was 0.824, which was higher than the diagnostic accuracy of other traditional tumor biomarkers.ConclusionCEBPA-AS1-containing exosomes secreted from GC cells could promote cell proliferation, inhibit apoptosis, and induce GC progression, indicating that exosomal CEBPA-AS1 is involved in cell-to-cell communication in GC carcinogenesis. Exosomal CEBPA-AS1 is a promising new biomarker for clinical diagnosis of GC.

Nuclear factor κB -inducing kinase is a diagnostic marker of gastric cancer.

Nuclear factor-κB-inducing kinase (NIK) is a new regulator of nuclear factor-κB signaling, which plays an important role in tumorigenesis. This study aimed to examine the expression of NIK in gastric cancer and investigate its clinical significance.Tumor issues were collected from 80 gastric cancer patients who received surgery and the diagnosis was confirmed by postoperative pathological analysis. The expression of NIK in gastric cancer tissues and adjacent normal mucosa was detected by immunohistochemical analysis. The associations between NIK expression and clinicopathological features of the patients were further analyzed.NIK expression was significantly higher in gastric cancer tissues than in adjacent normal tissues (P < .05). Furthermore, NIK expression showed significant association with UICC stage, T status, and differentiation, but not with age and gender of gastric cancer patients.NIK is overexpressed in gastric cancer and is a potential diagnostic marker of gastric cancer.

Exosomal long noncoding RNA lnc-GNAQ-6:1 may serve as a diagnostic marker for gastric cancer

BackgroundGastric cancer (GC) is one of the most aggressive cancers, with limited early diagnostic measures. Tumor-originated exosomal molecules are regarded as suitable candidates for non-invasive diagnosis. This study aimed to investigate the capacity of exosomal long noncoding RNA lnc-GNAQ-6:1 as a biomarker for early diagnosis of GC. MethodsIn this study, we collected sera from 43 patients with gastric cancer and 27 healthy subjects, then exosomes were isolated using commercial kits. Particle size analysis, Western bloting and protein-based exosomes quantification were conducted to identify the isolated exosomes and to evaluate its yield and purity. Expression levels of exosomal lnc-GNAQ-6:1 were detected by quantitative reverse transcription PCR (qRT-PCR). The serum concentrations of traditional biomarker (CA72-4, CEA, and CA19-9) were measured via a chemiluminescent detection system.The receiver operating characteristic curve (ROC) and area under curve (AUC) were used to estimate the diagnostic capacity. Furthermore, we analyzed the potential relationship between serum exosomal lnc-GNAQ-6:1 expression and clinicopathological parameters of gastric cancer. ResultsThe exosomes extracted in this study exhibited the typical exosome characteristics and purity. Patients with gastric cancer had the higher exosome yield than healthy volunteer. The results of qRT-PCR showed that compared with the healthy control, the expression of lnc-GNAQ-6:1 was significantly lower in the gastric cancer group. The area under the ROC curve is 0.732, which was higher than the diagnostic accuracy of CEA, CA 19–9 and CA72–4. However, the expression level of lnc-GNAQ-6:1 was not correlated with gender, age, tumor metastasis, serum carcinoembryonic antigen (CEA), carbohydrate antigen 19–9 (CA19-9), and carbohydrate antigen 72–4(CA72-4). ConclusionsOur data demonstrated that serum exosomal lnc-GNAQ-6:1 is lowly expressed in patient with gastric cancer and might be evaluated in larger studies as a new diagnostic marker for gastric cancer.

Clinical Significance of Matrix Metalloproteinases in Blood Plasma of Patients with Gastric Cancer.

Plasma levels of MMP-2, MMP-7, and MMP-9 and their tissue inhibitor TIMP-2 were measured in 89 patients with gastric cancer and the relationship between these parameters and the main clinical morphological characteristics of the disease was analyzed. Plasma levels of the proteins were measured using standard direct ELISA kits. The level of MMP-7 in patients with gastric cancer was significantly higher than in the control group (medians 2.7 and 1.2 ng/ml, respectively; p<0.01), but only in 51% patients this parameter surpassed the upper threshold normal value (2.35 ng/ml; 95% percentile of control). The level of MMP-9 in gastric cancer patients was lower than in control group by 1.6 times (medians 167 and 267 ng/ml, respectively; p<0.01). Plasma levels of MMP-2 and TIMP-2 in patients with gastric cancer and healthy subjects were similar. No appreciable associations of plasma matrixins and TIMP-2 with the main clinical morphological characteristics of the disease were detected. The patients were followed up for 8 to 85 months (median 70.8 months). Low level of MMP-2 and high level of MMP-7 in the plasma proved to be unfavorable prognostic factors for overall survival. At MMP-2<268 ng/ml, the 5-year overall survival was 32% vs. 60% for patients with the marker level higher than this threshold value (p=0.016). The differences in overall survival in relation to their MMP-7 levels for 5-year observation did not surpass 16% (39% at marker level >2.7 ng/ml and 55% at lower level; p=0.048). Plasma levels of MMP-2 and TIMP-2 were not significantly associated with overall survival. Multivariate analysis showed that only T index (p=0.034) and plasma MMP-7 level (p=0.007) were essential for overall survival. The increase in plasma or serum MMP-7 levels is a universal phenomenon in tumors of different histogenesis, which precluded the use of this parameter as a specific diagnostic marker of gastric cancer. At the same time, it could be useful for monitoring the treatment efficiency and detection of relapses. In addition, high plasma level of MMP-7 remained an independent factor of unfavorable prognosis for overall survival of patients with gastric cancer.

Gastrokine 1 protein is a potential theragnostic target for gastric cancer

BackgroundGastrokine 1 (GKN1) plays important roles in maintaining mucosal homeostasis, and in regulating cell proliferation and differentiation. Here, we determined whether GKN1 is a potential theragnostic marker for gastric cancer.MethodsWe identified GKN1 binding proteins using the protein microarray assay and investigated whether GKN1 is one of the exosomal cargo proteins by western blot, immunoprecipitation, and immunofluorescent assays. Cell proliferation and apoptosis were analyzed by MTT, BrdU incorporation, flow cytometry, and western blot assays. We further validated the functional relevance of exosomal GKN1 in MKN1-injected xenograft mice. The possibility of serum GKN1 as a diagnostic marker for gastric cancer was determined by ELISA assay.ResultsIn protein microarray assay, GKN1 binding to 27 exosomal proteins was clearly observed. GKN1 was expressed in exosomes derived from HFE-145 gastric epithelial cells by western blot and immunofluorescent assays, but not in exosomes from AGS and MKN1 gastric cancer cells. Exosomes carrying GKN1 inhibited cell proliferation and induced apoptosis in both AGS and MKN1 cells, and exosomes carrying GKN1-treated nude mice-bearing MKN1 xenograft tumors exhibited significantly reduced tumor volume and tumor weight. Silencing of clathrin markedly down-regulated the internalization of exosomal GKN1. Interestingly, serum GKN1 concentrations in patients with gastric cancer were significantly lower than those in healthy individuals and patients with colorectal and hepatocellular carcinomas.ConclusionsThe GKN1 is secreted and internalized in the gastric epithelium by exosome-driven transfer, which inhibits gastric tumorigenesis and supports the clinical application of GKN1 protein in gastric cancer diagnosis and treatment.

Glycoprofiling of Early Gastric Cancer Using Lectin Microarray Technology.

Recently, studies have reported that protein glycosylation plays an important role in the occurrence and development of cancer. Gastric cancer is a common cancer with high morbidity and mortality owing to most gastric cancers are discovered only at an advanced stage. Here, we aim to discover novel specific serum glycanbased biomarkers for gastric cancer. A lectin microarray with 50 kinds of tumor-associated lectin was used to detect the glycan profiles of serum samples between early gastric cancer and healthy controls. Then lectin blot was performed to validate the differences. The result of the lectin microarray showed that the signal intensities of 13 lectins showed significant differences between the healthy controls and early gastric cancer. Compared to the healthy, the normalized fluorescent intensities of the lectins PWA, LEL, and STL were significantly increased, and it implied that their specifically recognized GlcNAc showed an especially elevated expression in early gastric cancer. Moreover, the binding affinity of the lectins EEL, RCA-II, RCA-I, VAL, DSA, PHA-L, UEA, and CAL were higher in the early gastric cancer than in healthy controls. These glycan structures containing GalNAc, terminal Galβ 1-4 GlcNAc, Tri/tetraantennary N-glycan, β-1, 6GlcNAc branching structure, α-linked fucose residues, and Tn antigen were elevated in gastric cancer. While the two lectins CFL GNL reduced their binding ability. In addition, their specifically recognized N-acetyl-D-galactosamine structure and (α-1,3) mannose residues were decreased in early gastric cancer. Furthermore, lectin blot results of LEL, STL, PHA-L, RCA-I were consistent with the results of the lectin microarray. The findings of our study clarify the specific alterations for glycosylation during the pathogenesis of gastric cancer. The specific high expression of GlcNAc structure may act as a potential early diagnostic marker for gastric cancer.