Diagnosis Of GC Research Articles

Application of large-scale and multicohort plasma proteomics data to discover novel causal proteins in gastric cancer

PurposesGastric cancer (GC) is one of the most common malignant tumors threatening human beings and has a poor prognosis. Therefore, exploring unveiled biomarkers or therapeutic targets for the diagnosis and treatment of GC is crucial.MethodsA total of 5772 protein quantitative trait loci (pQTL) were aggregated from four latest large-scale proteomics cohorts. Two-sample Mendelian randomization (two-sample MR) was utilized to identify the causal effect of blood plasma proteins on GC. Heterogeneity, pleiotropy, and directionality analyses were employed to evaluate proteins identified via two-sample MR. The robustness of results was further validated via colocalization. The drug targets of proteins were evaluated to reveal the compounds that can interfere with these proteins.ResultsTen proteins with potential causations in relation to GC were identified: LY6D, SLURP1, MLN, PSCA, THSD1, CFTR, PPM1B, KDM3A, TSC1, and HCG22. Among these proteins, LY6D, SLURP1, and THSD1 were considered as the most reliable biomarkers of GC due to their significant H4 posterior probabilities in colocalization analysis and absence of pleiotropy. Compound 35, nitrosamide, and 0175029-0000 were potential drugs or small molecules targeting LY6D, SLURP1, and THSD1, respectively.ConclusionThis study identified several plasma proteins as potential biomarkers of GC and provided data support and new insights into the early diagnosis, intervention, and therapeutic targets of GC.

Integrated multi-omics analysis and machine learning developed a prognostic model based on mitochondrial function in a large multicenter cohort for Gastric Cancer

BackgroundGastric cancer (GC) is a common and aggressive type of cancer worldwide. Despite recent advancements in its treatment, the prognosis for patients with GC remains poor. Understanding the mechanisms of cell death in GC, particularly those related to mitochondrial function, is crucial for its development and progression. However, more research is needed to investigate the significance of the interaction between mitochondrial function and GC cell death.MethodsWe employed a robust computational framework to investigate the role of mitochondria-associated proteins in the progression of GC in a cohort of 1,199 GC patients. Ten machine learning algorithms were utilized and combined into 101 unique combinations. Ultimately, we developed a Mitochondrial-related-Score (MitoScore) using the machine learning model that exhibited the best performance. We observed the upregulation of LEMT2 and further explored its function in tumor progression. Mitochondrial functions were assessed by measuring mitochondrial ATP, mitochondrial membrane potential, and levels of lactate, pyruvate, and glucose.ResultsMitoScore showed significant correlations with GC immune and metabolic functions. The higher MitoScore subgroup exhibited enriched metabolic pathways and higher immune activity. Overexpression of LETM2 (leucine zipper and EF-hand containing transmembrane protein 2) significantly enhanced tumor proliferation and metastasis. LETM2 plays a role in promoting GC cell proliferation by activating the mTOR pathway, maintaining mitochondrial homeostasis, and promoting glycolysis.ConclusionThe powerful machine learning framework highlights the significant potential of MitoScore in providing valuable insights and accurate assessments for individuals with GC. This study also enhances our understanding of LETM2 as an oncogene signature in GC. LETM2 may promote tumor progression by maintaining mitochondrial health and activating glycolysis, offering potential targets for diagnosis, treatment, and prognosis of GC.

Targeted plasma proteomic analysis uncovers a high-performance biomarker panel for early diagnosis of gastric cancer

BackgroundGastric cancer (GC) is characterized by high morbidity, high mortality and low early diagnosis rate. Early diagnosis plays a crucial role in radically treating GC. The aim of this study was to identify plasma biomarkers for GC and early GC diagnosis. MethodsWe quantified 369 protein levels with plasma samples from discovery cohort (n = 88) and validation cohort (n = 50) via high-throughput proximity extension assay (PEA) utilizing the Olink-Explore-384-Cardiometabolic panel. The multi-protein signatures were derived from LASSO and Ridge regression models. ResultsIn the discovery cohort, 13 proteins (GDF15, ITIH3, BOC, DPP7, EGFR, AMY2A, CCDC80, CD163, GPNMB, LTBP2, CTSZ, CCL18 and NECTIN2) were identified to distinguish GC (Stage I-IV) and early GC (HGIN-I) groups from control group with AUC of 0.994 and AUC of 0.998, severally. The validation cohort yielded AUC of 0.930 and AUC of 0.818 for GC and early GC, respectively. ConclusionsThis study identified a multi-protein signature with the potential to benefit clinical GC diagnosis, especially for Asian and early GC patients, which may contribute to the development of a less-invasive, convenient, and efficient early screening tool, promoting early diagnosis and treatment of GC and ultimately improving patient survival.

LUM as a novel prognostic marker and its correlation with immune infiltration in gastric cancer: a study based on immunohistochemical analysis and bioinformatics

BackgroundGastric cancer (GC) is considered the sixth highly prevailing malignant neoplasm and is ranked third in terms of cancer mortality rates. To enable an early and efficient diagnosis of GC, it is important to detect the fundamental processes involved in the oncogenesis and progression of gastric malignancy. The understanding of molecular signaling pathways can facilitate the development of more effective therapeutic strategies for GC patients.MethodsThe screening of genes that exhibited differential expression in early and advanced GC was performed utilizing the Gene Expression Omnibus databases (GSE3438). Based on this, the protein and protein interaction network was constructed to screen for hub genes. The resulting list of hub genes was evaluated with bioinformatic analysis and selected genes were validated the protein expression by immunohistochemistry (IHC). Finally, a competing endogenous RNA network of GC was constructed.ResultsThe three genes (ITGB1, LUM, and COL5A2) overexpressed in both early and advanced GC were identified for the first time. Their upregulation has been linked with worse overall survival (OS) time in patients with GC. Only LUM was identified as an independent risk factor for OS among GC patients by means of additional analysis. IHC results demonstrated that the expression of LUM protein was increased in GC tissue, and was positively associated with the pathological T stage. LUM expression can effectively differentiate tumorous tissue from normal tissue (area under the curve = 0.743). The area under 1-, 3-, and 5-year survival relative operating characteristics were greater than 0.6. Biological function enrichment analyses suggested that the genes related to LUM expression were involved in extracellular matrix development-related pathways and enriched in several cancer-related pathways. LUM affects the infiltration degree of cells linked to the immune system in the tumor microenvironment. In GC progression, the AC117386.2/hsa-miR-378c/LUM regulatory axis was also identified.ConclusionCollectively, a thorough bioinformatics analysis was carried out and an AC117386.2/hsa-miR-378c/LUM regulatory axis in the stomach adenocarcinoma dataset was detected. These findings should serve as a guide for future experimental investigations and warrant confirmation from larger studies.

Microbial-Related Metabolites May Be Involved in Eight Major Biological Processes and Represent Potential Diagnostic Markers in Gastric Cancer.

Metabolites associated with microbes regulate human immunity, inhibit bacterial colonization, and promote pathogenicity. Integrating microbe and metabolome research in GC provides a direction for understanding the microbe-associated pathophysiological process of metabolic changes and disease occurrence. The present study included 30 GC patients with 30 cancerous tissues and paired non-cancerous tissues (NCs) as controls. LC-MS/MS metabolomics and 16S rRNA sequencing were performed to obtain the metabolic and microbial characteristics. Integrated analysis of the microbes and metabolomes was conducted to explore the coexistence relationship between the microbial and metabolic characteristics of GC and to identify microbial-related metabolite diagnostic markers. The metabolic analysis showed that the overall metabolite distribution differed between the GC tissues and the NC tissues: 25 metabolites were enriched in the NC tissues and 42 metabolites were enriched in the GC tissues. The α and β microbial diversities were higher in the GC tissues than in the NC tissues, with 11 differential phyla and 52 differential genera. In the correlation and coexistence integrated analysis, 66 differential metabolites were correlated and coexisted, with specific differential microbes. The microbes in the GC tissue likely regulated eight metabolic pathways. In the efficacy evaluation of the microbial-related differential metabolites in the diagnosis of GC, 12 differential metabolites (area under the curve [AUC] >0.9) exerted relatively high diagnostic efficiency, and the combined diagnostic efficacy of 5 to 6 microbial-related differential metabolites was higher than the diagnostic efficacy of a single feature. Therefore, microbial diversity and metabolite distribution differed between the GC tissues and the NC tissues. Microbial-related metabolites may be involved in eight major metabolism-based biological processes in GC and represent potential diagnostic markers.

Exosomes-mediated transfer of LINC00691 regulates the formation of CAFs and promotes the progression of gastric cancer

ObjectiveGastric cancer (GC) is one of the malignant tumors with the highest mortality worldwide. Our previous studies have revealed that LINC00691 is up-regulated in serum of GC patients as a novel potential biomarker for GC diagnosis and prognosis. However, the roles of serum exosomal LINC00691 in GC has not been clarified. This study aimed to find the expression pattern of serum exosomal LINC00691 in GC patients and the correlation between the level of serum exosomal LINC00691 and the pathology of gastric cancer patients.MethodsWe collected the serum of 94 GC patients before surgery and extracted exosomes to detect the expression level of exosomal LINC00691, with 21 healthy volunteers and 17 patients with benign gastric diseases as controls. Surgical GC tissues and paired healthy tissues were collected to culture primary cancer-associated fibroblasts (CAFs) and normal fibroblasts (NFs). We then treated NFs with LINC00691-rich GC cell culture supernatant or exosomes and detected the activation markers and biological functions of the fibroblasts.ResultsThe results of real-time qPCR indicated that the serum exosomal LINC00691 of GC patients was significantly higher than that of healthy subjects and patients with benign gastric diseases, and was associated with the clinicopathology of GC patients. More interestingly, when the NFs were treated with GC exosomes, the level of LINC00691 was significantly increased, the cell proliferation and migration were noticeably enhanced, and the ability to accelerate GC cell proliferation and invasion was promoted, which means that the induced fibroblasts gained the properties of CAFs. In addition, we found that knockdown of LINC00691 and the use of the JAK2/STAT3 signaling pathway inhibitor ruxolitinib effectively deprived exosome-containing GC cell supernatants of the effects on NFs.ConclusionOur study suggested that exosomal LINC00691 promoted NFs to gained the properties of CAFs depending on JAK2/STAT3 signaling pathway as a potential diagnostic biomarker for GC.

Latin American young patients with gastric adenocarcinoma: worst prognosis and outcomes.

Incidence of young patients (aged 40 years or younger) diagnosed with gastric carcinoma has increased worldwide. Young GC diagnosis, have clinicopathological features that differ from elderly, and is correlated with bad prognosis factors. The purpose of this work is to describe the prevalence, clinic-pathological features, and prognosis of overall survival (OS) of young Latin-American patients with GC. Retrospective, observational study. Included patients treated at the National Cancer Institute [2004-2020]. Statistical analysis: χ2 and t-test, Kaplan-Meier, Log-Rank and Cox-Regression. Statistical significance differences were assessed when P was bilaterally <0.05. A total of 2,543 patients fulfilled the inclusion criteria. Young-patients were predominantly female (54%), with diffuse-type adenocarcinoma (68%), signet-ring-cell (72%), poor-differentiation (90%), and metastatic (79%). In OS analysis, patients with metastatic disease, showed differences regarding age, young patients reported a median-OS of 8 versus 13 months for elderly patients (P=0.001). Among young patients, differences were also observed regarding gender, young-female patients had a median-OS of 5 versus 11 months for young-man (P=0.001). This is one of the pioneer studies correlating age with gender and the prognostic features of bad prognosis in Latin-American population. Besides, supports the idea that a global effort is required to improve awareness, prevention, and early diagnosis of GC.

Identification of novel prognostic circRNA biomarkers in circRNA-miRNA-mRNA regulatory network in gastric cancer and immune infiltration analysis

BackgroundGastric cancer (GC) carries significant morbidity and mortality globally. An increasing number of studies have confirmed that circular RNA (circRNA) is tightly associated with the carcinogenesis and development of GC, especially acting as a competing endogenous RNA for miRNAs.ObjectiveOur study aimed to construct the circRNA-miRNA-mRNA regulatory network and analyze the function and prognostic significance of the network using bioinformatics tools.MethodsWe first downloaded the GC expression profile from the Gene Expression Omnibus database and identified differentially expressed genes and differentially expressed circRNAs. Then, we predicted the miRNA-mRNA interaction pairs and constructed the circRNA-miRNA-mRNA regulatory network. Next, we established a protein-protein interaction network and analyzed the function of these networks. Finally, we primarily validated our results by comparison with The Cancer Genome Atlas cohort and by performing qRT-PCR.ResultsWe screened the top 15 hub genes and 3 core modules. Functional analysis showed that in the upregulated circRNA network, 15 hub genes were correlated with extracellular matrix organization and interaction. The function of downregulated circRNAs converged on physiological functions, such as protein processing, energy metabolism and gastric acid secretion. We ascertained 3 prognostic and immune infiltration-related genes, COL12A1, COL5A2, and THBS1, and built a nomogram for clinical application. We validated the expression level and diagnostic performance of key prognostic differentially expressed genes.ConclusionsIn conclusion, we constructed two circRNA-miRNA-mRNA regulatory networks and identified 3 prognostic and screening biomarkers, COL12A1, COL5A2, and THBS1. The ceRNA network and these genes could play important roles in GC development, diagnosis and prognosis.

Metabolomic profiling of plasma reveals potential biomarkers for screening and early diagnosis of gastric cancer and precancerous stages

AbstractGastric cancer (GC) faces a great challenge in clinical diagnosis, that it often is detected at advanced stages and there is a loss of optimum time for treatment. Thus, it is necessary to develop effective strategies for diagnosis of GC. In this study, 82 participants were enrolled, including 50 chronic superficial gastritis (CSG) patients, 7 early gastric cancer (EGC), and 25 advanced gastric cancer (AGC) ones. Metabolites profiling on patient plasma was performed. Furthermore, the proposed biomarkers were used to create random forest models, in which discrimination efficiency and accuracy were ascertained by receiver operating characteristic (ROC) curve analysis. l‐carnitine, l‐proline, pyruvaldehyde, phosphatidylcholines (PC) (14:0/18:0), lysophosphatidylcholine (14:0) (LysoPC 14:0), lysinoalanine were defined as the potential biomarker panel for the diagnosis among CSG and EGC patients. Compared with EGC patients, PC(O‐18:0/0:0) and LysoPC(20:4(5Z,8Z,11Z,14Z)) were found to be upregulated in AGC patients, whereasl‐proline, l‐valine, adrenic acid, and pyruvaldehyde downregulated. Pathway analysis revealed several metabolism disorders, involving amino acids and lipid metabolism. ROC analysis demonstrated a high diagnostic performance in disease diagnosis between CSG and GC. The above results indicate that the biomarker panels are sensitive to early diagnosis of GC disease, which is expected to be a promising diagnostic tool for disease stratification studies.

Intertumor heterogeneity of locally advanced gastric cancer.

435 Background: The aim of the present study was to determine to the effect of HER2, dMMR, PD-L1 status in the primary tumor and in metastasis to the regional lymph node of GC patients. Methods: A total of 44 patients with primary loco-regional (N+) gastric adenocarcinoma were recruited, and two formalin-fixed paraffin-embedded (FFPE) tumor-containing blocks of each patient (one block with primary tumor and one block with metastasis to the regional lymph node)were selected for HER2, dMMR, PD-L1 (CPS) immunohistochemical (IHC) assay. Clinicopathological characteristics were recorded, and intertumoral heterogeneity of HER2, dMMR, PD-L1 IHC expression was determined. Results: The study included 19 women and 25 men, 30 patients had Laurén’s intestinal type of cancer, 14 had a Laurén’s diffuse type. In 5 patients (11.4%) overexpression of Her-2 neu was detected, and heterogeneity was detected in all five cases: in three patients with HER2 overexpression in the primary tumor, no overexpression was detected in the metastasis to the regional lymph node, in two cases overexpression was detected in the metastasis, while no overexpression was observed in the primary tumor. 2 patients showed signs of dMMR (4.5%), in one case, heterogeneity in dMMR status was also revealed: signs of dMMR in the primary tumor and its absence in regional metastasis (pMMR). Assessment of PD-L1 status was carried out using the CPS formula. Ten patients (22.7%) had a negative PD-L1 status (CPS=0) both in the primary tumor and in regional metastasis. Positive PD-L1 status in the primary tumor: in 24 patients CPS= 0-5 (54.5%), in 5 patients CPS= 5-10 (11.4%) and 5 patients CPS= 10 or more (11.4% ). Positive PD-L1 status in regional lymph node metastasis: in 24 patients CPS= 0-5 (54.5%), in 5 patients CPS= 5-10 (11.4%) and in 5 patients CPS= 10 or more ( 11.4%). In 5 cases (11.4%) marked heterogeneity in PD-L1 status between the primary tumor and its regional metastasis (1 case with dMMR heterogeneity). Conclusions: The research findings in this paper indicate that the intertumoral heterogeneity of HER2 overexpression is common in GC patients, We highly recommend multi-block HER2 assessment for accurate diagnosis of GC. Given the rarity of status detection dMMR, a study in a larger number of patients is required, however, our data also confirm the presence of heterogeneity in dMMR status, and probably the possibility of metastasis of a more aggressive pMMR clone. Heterogeneity in PD-L1 status is quite rare and amounted to only 11.4%, which also has important practical significance.

Exosomal LINC00355 promotes the malignant progression of gastric cancer through histone deacetylase HDAC3-mediated TP53INP1 transcriptional inhibition

AimsExosomes are a subpopulation of extracellular vesicles (EV) derived from multivesicular body (MVB) that transmit various cellular molecular constituents, including long noncoding RNAs (lncRNAs), to promote intercellular communication.Our aim was to investigate the function and mechanism of exosomal LINC00355 in gastric cancer cells. Main methodsExosomal levels of LINC00355 in GC patients and healthy controls were measured by RT–qPCR. The effects of exosomal LINC00355 on GC cell viability, proliferation, migration and invasion were evaluated by CCK8, colony formation, Transwell and wound healing assays. The expression levels of Ki67 in xenograft tumor tissues were confirmed by immunohistochemistry assay, and apoptosis was analyzed by TUNEL apoptosis assay. Western blotting was used to monitor protein expression. RNA immunoprecipitation and RNA pulldown were performed to detect the interaction between LINC00355 and HDAC3. Chromatin immunoprecipitation was used to assess the interaction of HDAC3 with the TP53INP1 promoter. Key findingsExosomal LINC00355 levels were higher in plasma from gastric cancer patients than in plasma from healthy volunteers. Exosomal LINC00355 promoted the proliferation, migration and invasion of gastric cancer cell lines. RNA sequence analysis demonstrated that LINC00355 knockdown downregulated histone deacetylase HDAC3 and upregulated TP53INP1. Mechanistic investigation indicated that exosomal LINC00355 interacted with HDAC3 to suppress TP53INP1 transcription, which promoted epithelial-mesenchymal transition (EMT). SignificanceExosomal LINC00355 plays a pivotal role in regulating EMT to induce the malignant progression of GC. Exosomal LINC00355 could be a promising biomarker in the early diagnosis and prognosis of GC.

Evaluation of CEP55, SERPINE1 and SMPD3 genes and proteins as diagnostic and prognostic biomarkers in gastric carcinoma in Egyptian patients

BackgroundGastric carcinoma (GC) is a fatal disease. Detection of new biomarkers that can be utilized in the early diagnosis of GC is a pressing need. This present study assessed centrosomal protein-55 (CEP55)’ serpin family E member 1 (SERPINE1) and sphingomyelin phosphodiesterase 3 (SMPD3) genes and proteins in gastric adenocarcinoma with different tumor progression features. Thirty surgically resected gastric tissue samples from thirty patients suffered from gastric cancers were obtained. The gastric tissue samples were divided into tumorous (with different stages and grades) and adjacent non-tumorous samples. CEP55, SERPINE1 and SMPD3 genes were assessed by quantitative qRT-PCR, and their proteins were assessed by ELISA in the gastric tissue samples.ResultsAs regards SERPINE1, CEP55 genes and proteins, results revealed significant elevations in the GC samples (p < 0.0001). On the contrary, SMPD3 gene and protein revealed significant decreases as compared to non-tumorous samples. The studied genes and proteins showed highly significant specificity and sensitivity in the early detection of GC. SERPINE1 gene and protein revealed highly significant increases and positive correlations, while SMPD3 gene and protein revealed highly significant decreases and negative correlations as the tumor progresses.ConclusionCEP55, SERPINE1 and SMPD3 genes and proteins could be used as useful biomarkers for the early detection of GC. SERPINE1 and SMPD3 genes and proteins might be used as risk and protective prognostic factors in GC, respectively.

Evaluation of multiple biological indicators for combined diagnosis of gastric cancer: A retrospective analysis.

To assess carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), platelet distribution width (PDW), neutrophil-to-lymphocyte ratio (NLR), and platelet-lymphocyte ratio (PLR) for gastric cancer's (GC) diagnostic efficiency, and the use of receiver operating characteristic curves (ROC) combined with logistic regression to evaluate multi-index combination's diagnostic value of GC. 773 GC patients' clinical data were retrospectively collected in the Weihai Municipal Hospital, affiliated hospital of Shandong University from April 2018 to May 2021, and selected 2368 healthy physical examination patients during the same period as the control group. A total of 3141 samples was included in this study, including 773 cases in the GC group and 2368 cases in the healthy physical examination group. The results of the overall comparison between groups showed that apart from gender, the age differences, CEA, CA19-9, PDW, NLR, and PLR were statistically significant (P < .001). Spearman ranks correlation analysis's results showed that CA19-9, CEA, PLR, and NLR were correlated with GC patients' clinical-stage positively, and the correlation coefficients r was 0.249, 0.280, 0.252, 0.262 (all P < .001), and PDW was correlated with the clinical stage negatively (r = -0.186, P < .001). The ROC curve analysis results of CEA, CA19-9, PDW, NLR and PLR showed that CEA's diagnostic cutoff value for GC was 3.175 (area under the curve [AUC] = 0.631, 95% CI: 0.606-0.655, P < .001), the CA19-9's diagnostic cutoff value is 19.640 (AUC = 0.589, 95% CI: 0.563-0.615, P < .001), PDW's diagnostic cutoff value is 15.750 (AUC = 0.799, 95% CI: 0.778-0.820, P < .001), NLR's diagnostic cutoff value was 2.162 (AUC = 0.699, 95% CI: 0.675-0.721, P < .001), and PLR's diagnostic cutoff value was 149.540 (AUC = 0.709, 95% CI: 0.688-0.732, P < .001). The area under the ROC curve for the combined diagnosis of GC with 5 indicators was 0.877 (95% CI: 0.860-0.894, P < .001), which was better than a single indicator (P < .05). The diagnostic efficiency of combined detection of CEA, CA19-9, PDW, NLR, and PLR is better than that of single index detection alone, which can reduce the misdiagnosis rate of GC effectively.

Feasibility and reproducibility of a plasma-based multiplex DNA methylation assay for early detection of gastric cancer

BackgroundGastric cancer (GC) is a leading cause of cancer death and an important barrier to increasing life expectancy in China. Early detection of GC can significantly reduce its mortality rate. MethodsA new plasma-based multiplex DNA methylation assay combining simultaneous detection of three biomarkers (KCNQ5, C9orf50 and CLIP4) and one control gene (ACTB) was developed. It was used to examine 12 paired tissue samples and a training cohort of 151 plasma samples. Its performance was subsequently confirmed in validation cohort 1 (n = 105) and validation cohort 2 (n = 139). ResultsThree methylation markers showed significantly higher methylation levels in GC tissues than in paired adjacent tissues. The assay showed a sensitivity of 67.9 % with a specificity of 86.6 % for GC detection in the training cohort, and the AUC was 0.786 (95 % CI: 0.701–0.855). The methylation levels in GC patients were significantly higher than those in benign gastric tumors and in control group. Meanwhile, the assay achieved a sensitivity of 65.5 % with a specificity of 90.0 % in the validation cohort 1, and the AUC was 0.805 (95 % CI: 0.716–0.876). In the validation cohort 2, its sensitivity and specificity were 73.7 % and 84.1 %, respectively, and the AUC was 0.851 (95 % CI: 0.776–0.909). ConclusionThe plasma-based multiplex DNA methylation assay was highly specific for GC early detection. It has the potential to become an alternative approach to improve diagnosis of GC in the clinics.

Performance of Salivary Extracellular RNA Biomarker Panels for Gastric Cancer Differs between Distinct Populations.

Simple SummaryGastric cancer (GC) is the fourth most common cancer that occurs worldwide, affecting specifically the Asian population. Currently, there are no available screening programs for GC in United States. Since saliva is a highly desirable body fluid for developing biomarkers of cancer screening, early detection, and monitoring, we previously reported that salivary extracellular RNAs could be developed to detect gastric cancer in a Korean cohort, and here, we validate them in a U.S. cohort. Our study emphasizes the importance of population-specific biomarker development and validation, and specifically, the noninvasive nature of salivary biomarkers for population-based screening in at-risk populations.Gastric cancer (GC) has the fifth highest incidence among cancers and is the fourth leading cause of cancer-related death GC has predominantly a higher number of cases in certain ethnic groups such as the Korean population. GC found at an early stage is more treatable and has a higher survival rate as compared with GC found at a late stage. However, a diagnosis of GC is often delayed due to the lack of early symptoms and available screening programs in United States. Extracellular RNA (exRNA) is an emerging paradigm; exRNAs have the potential to serve as biomarkers in panels aimed at early detection of cancer. We previously reported the successful use of a panel of salivary exRNA for detecting GC in a high-prevalence Korean cohort, and that genetic changes reflected cancer-associated salivary exRNA changes. The current study is a case-control study of salivary exRNA biomarkers for detecting GC in an ethnically distinct U.S. cohort. A model constructed for the U.S. cohort combined demographic characteristics and salivary miRNA and mRNA biomarkers for GC and yielded an area under the receiver operating characteristic (ROC) curve (AUC) of 0.78. However, the constituents of this model differed from that constructed for the Korean cohort, thus, emphasizing the importance of population-specific biomarker development and validation.

Abstract 5943: Association between the consumption of meat and carbonated drinks and early onset gastric cancer in Chilean patients

Abstract Gastric cancer (GC) is the 5th most frequent neoplasm and the 3rd cancer with the highest mortality according to GLOBOCAN. GC is often diagnosed in middle aged and elderly people, with a peak in incidence between 60 and 70 years old. In contrast, early-onset GC is the GC had a strong hereditary component. Associations of sporadic late onset-GC and dietary factors have been published but the role of nutritional factors in early onset GC is unknown. The aim of this study is to investigate the association between the intake of red meat, pork, processed meats and carbonated drinks in a group of early-onset GC. Our study was carried out in 19 Chilean early-onset GC patients, aged between 32 and 60 years, and 32 healthy age matched individuals from the same population. Through a survey of nutritional habits carried out retrospectively considering the stage prior to the diagnosis of GC, we determined the amount, type and frequency of ingestion of red meat, pork, processed meat and carbonated beverages. To measure the association an odds ratio and non-parametric association statistic tests were used. For the association of meat intake, we used the WHO recommendation (less than 70 g of meat per day) to classify the meat consumption levels in both groups. An odds ratio of 25.5 (4.8-135.4, p=8.3x105) was determined between the consumption of more than 70 g of meat per day in the early onset GC group vs the control group. Even though there are no international recommendations for carbonated drinks consumption levels, we found a higher carbonated drink consumption among cases (cases: Ave.= 180,7, SD= ±108,5 vs controls: Ave.=43,3, SD=±38,3. P=0033). In conclusion, our results shows significant associations between the consumption of red meat, pork, processed meats, and carbonated drinks in the risk of early-onset GC patients compared with the control group. Our findings, suggest that nutritional factors could play a role in the early GC presentation, acting in conjunction with low penetrance gene mutations. We will incorporate more early onset patients to the study group and do a sex matching for the control group to evaluate this possible confounding factor. We will also incorporate a late onset GC group. We think that nutritional factors could be an important factor to modulate genetic risk, even in early-onset patients. Beca Chile Postdoctorado 74190063 to GM. Citation Format: Carol Parra, Graciela Molina, Carla Coo, Jessica López, María San Martín, Javiera Siche, Luis Carvajal-Carmona. Association between the consumption of meat and carbonated drinks and early onset gastric cancer in Chilean patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5943.

Evaluation of serum tRF-23-Q99P9P9NDD as a potential biomarker for the clinical diagnosis of gastric cancer

BackgroundGastric cancer (GC) is one of the diseases that endanger human health with high morbidity and mortality. The positive rates of traditional biomarkers in the diagnosis of GC are low, so it is necessary to find biomarkers with high sensitivity to increase the detection rate. tRNA-derived small RNAs (tsRNAs) are novel small non-coding RNAs with specific biological functions and aberrant expression in cancer. In this study, we focused on the potential of tRNA-derived small RNAs as GC biomarkers.MethodsThe differentially expressed tsRNAs in three pairs of GC tissues were screened with high-throughput sequencing and verified using the TCGA database and Quantitative real-time PCR. The methodological evaluation of tRF-23-Q99P9P9NDD was verified by agarose gel electrophoresis, RIN evaluation, and Sanger sequencing. The Chi-square test was used to evaluate the relationship between the tRF-23-Q99P9P9NDD expression and clinicopathological parameters. Kaplan–Meier survival analysis was used to evaluate the effect of the tRF-23-Q99P9P9NDD expression on survival. Additionally, the receiver operating characteristic curve (ROC) was used to evaluate the diagnostic efficacy of tRF-23-Q99P9P9NDD in GC.ResultsDifferential expression of serum tRF-23-Q99P9P9NDD could distinguish GC patients from gastritis patients and healthy donors. Chi-square test showed that high expression of tRF-23-Q99P9P9NDD was significantly associated with T stage, lymph node metastasis, TNM stage, and nerve/vascular invasion. Kaplan–Meier curve showed that patients with high expression of tRF-23-Q99P9P9NDD had a lower survival rate than patients with low expression of this biomarker. ROC analysis showed that, compared with conventional biomarkers, the efficacy of tRF-23-Q99P9P9NDD was higher, which was improved by the combination of biomarkers, and even in the early stages. Finally, we preliminarily predicted the downstream of tRF-23-Q99P9P9NDD in GC cells.ConclusionsThe expression of tRF-23-Q99P9P9NDD in GC serum can identify GC patients, and it has higher efficacy than conventional biomarkers even in the early stages. Furthermore, tRF-23-Q99P9P9NDD can monitor the postoperative conditions of GC patients.

Evaluation of CSTB and DMBT1 expression in saliva of gastric cancer patients and controls

BackgroundGastric cancer (GC) is the fifth most common cancer and the third cause of cancer deaths globally, with late diagnosis, low survival rate, and poor prognosis. This case-control study aimed to evaluate the expression of cystatin B (CSTB) and deleted in malignant brain tumor 1 (DMBT1) in the saliva of GC patients with healthy individuals to construct diagnostic algorithms using statistical analysis and machine learning methods.MethodsDemographic data, clinical characteristics, and food intake habits of the case and control group were gathered through a standard checklist. Unstimulated whole saliva samples were taken from 31 healthy individuals and 31 GC patients. Through ELISA test and statistical analysis, the expression of salivary CSTB and DMBT1 proteins was evaluated. To construct diagnostic algorithms, we used the machine learning method.ResultsThe mean salivary expression of CSTB in GC patients was significantly lower (115.55 ± 7.06, p = 0.001), and the mean salivary expression of DMBT1 in GC patients was significantly higher (171.88 ± 39.67, p = 0.002) than the control.Multiple linear regression analysis demonstrated that GC was significantly correlated with high levels of DMBT1 after controlling the effects of age of participants (R2 = 0.20, p < 0.001).Considering salivary CSTB greater than 119.06 ng/mL as an optimal cut-off value, the sensitivity and specificity of CSTB in the diagnosis of GC were 83.87 and 70.97%, respectively. The area under the ROC curve was calculated as 0.728. The optimal cut-off value of DMBT1 for differentiating GC patients from controls was greater than 146.33 ng/mL (sensitivity = 80.65% and specificity = 64.52%). The area under the ROC curve was up to 0.741.As a result of the machine learning method, the area under the receiver-operating characteristic curve for the diagnostic ability of CSTB, DMBT1, demographic data, clinical characteristics, and food intake habits was 0.95. The machine learning model’s sensitivity, specificity, and accuracy were 100, 70.8, and 80.5%, respectively.ConclusionSalivary levels of DMBT1 and CSTB may be accurate in diagnosing GCs. Machine learning analyses using salivary biomarkers, demographic, clinical, and nutrition habits data simultaneously could provide affordability models with acceptable accuracy for differentiation of GC by a cost-effective and non-invasive method.

Gene profiling of SEC13, SMAD7, GHRL, long non-coding RNA GHRLOS, HIF-1\u03b1 in gastric cancer patients

Even with considerable progress in cancer researches, gastric cancer is still one of the global health problems. Recognition of the differential expressed genes in GC is the most appropriate approach for establishing new diagnostic targets. This study evaluates SEC13, SMAD7, GHRL, lncRNA GHRLOS, HIF-1α genes profiling as well as HIF-1α protein level for GC. The expression of selected genes, serum HIF-1α and CEA protein levels were determined for 50 GC patients and 50 healthy controls by real-time RT-PCR, ELISA, and ELICA respectively. The sensitivities of these parameters as diagnostic biomarkers were evaluated. SMAD7, HIF-1α expression, serum HIF-1α, and CEA level were significantly upregulated in GC patients as compared to the control group (P = 0.024, < 0.001) and had significant positive correlations between each other except SMAD7 with serum HIF-1α, and CEA level. On the other hand, SEC13, GHRL, and lncRNA GHRLOS expression were significantly downregulated in GC patients (P = < 0.001, 0.025, < 0.001 respectively) and had significant positive correlations with each other (P < 0.001). Significant negative correlations were observed between most of both groups. All studied parameters were associated with GC clinical stages except SMAD7 was associated with stage IV only (P = 0.005) and GHRL did not associate with tumor stages (P ˃ 0.05). All studied parameters may be promising biomarkers for the early diagnosis of GC. SMAD7, HIF-1α gene, and HIF-1α protein may be jointly implicated in cancer development and prognosis, while SEC13, GHRL, and lncRNA GHRLOS may act as tumor suppressors.

Hsa-miR-875-5p inhibits tumorigenesis and suppresses TGF-\u03b2 signalling by targeting USF2 in gastric cancer

BackgroundGastric cancer (GC) is one of the most common malignancies, and an increasing number of studies have shown that its pathogenesis is regulated by various miRNAs. In this study, we investigated the role of miR-875-5p in GC.MethodsThe expression of miR-875-5p was detected in human GC specimens and cell lines by miRNA qRT–PCR. The effect of miR-875-5p on GC proliferation was determined by Cell Counting Kit-8 (CCK-8) proliferation and 5-ethynyl-2′-deoxyuridine (EdU) assays. Migration and invasion were examined by transwell migration and invasion assays as well as wound healing assays. The interaction between miR-875-5p and its target gene upstream stimulatory factor 2(USF2) was verified by dual luciferase reporter assays. The effects of miR-875-5p in vivo were studied in xenograft nude mouse models. Related proteins were detected by western blot.ResultsThe results showed that miR-875-5p inhibited the proliferation, migration and invasion of GC cells in vitro and inhibited tumorigenesis in vivo. USF2 was proved to be a direct target of miR-875-5p. Knockdown of USF2 partially counteracted the effects of miR-875-5p inhibitor. Overexpression of miR-875-5p could inhibit proliferation, migration and invasion and suppress the TGF-β signalling pathway by downregulating USF2.ConclusionsMiR-875-5p can inhibit the progression of GC by directly targeting USF2. And in the future, miR-875-5p is expected to be a potential target for GC diagnosis and treatment.