Recent advances in the molecular diagnostics of gastric cancer

Cytotoxic effects of the standardized extract from Curcuma aromatica Salisb. rhizomes via induction of mitochondria-mediated caspase-dependent apoptotic pathway and p21-mediated G0/G1 cell cycle arrest on human gastric cancer AGS cells

Curcuma aromatica Salisb. (C. aromatica) is one of the traditional herbs used to treat microbial infection, skin eruption, coronary heart disease, and other diseases, including cancer. However, the inhibitory effects and underlying mechanisms of action of C. aromatica on gastric cancer cells have not yet been fully elucidated. Our study aimed to examine the possible molecular mechanisms underlying the cytotoxic effects attributed to C. aromatica rhizome standardized extract against gastric cancer cells. The components of two major active compounds in C. aromatica rhizome extract were quantitatively analyzed using a simple and validated HPLC method. Cytotoxicity was determined in different gastric cancer and non-cancer cell lines. The biological activities of the extract targeting apoptosis and cell cycle-related genes on gastric cancer AGS cells were also investigated to elucidate the mechanisms relating to the anti-proliferative effect of C. aromatica rhizomes. The two major active compounds curdione and germacrone, in the C. aromatica extract were standardized to 0.64% and 1.12% w/w, respectively. The standardized extract (CAE) exerted cytotoxic effects on various cancer cells, whereas minimal effects at equivalent doses were noted for normal cells. CAE concentration-dependently suppressed growth of gastric cancer AGS cells via induction of apoptosis. Further studies revealed that CAE treatment disrupted mitochondrial membrane potential (ΔΨm), increased Bax/Bcl-2 ratio, and cytochrome c release, resulting in activation of caspase-9/-3 and subsequent cleavage of PARP. Further, the inhibitory effects of caspase-9/-3 expression by a synthetic pan-caspase inhibitor partially protected cells against apoptosis following CAE treatment. In addition, CAE significantly promoted cell death in AGS cells via an accumulation of cells in the G0/G1 phase. This effect was associated with upregulation of the CDK inhibitor p21 and downregulation of cyclin D1, cyclin E, CDK4, and CDK2 expression. Our data indicated that CAE exerted anti-proliferative activity by activating the mitochondria-mediated caspase-dependent apoptotic pathway and arresting the p21-mediated G0/G1 cell cycle on human gastric cancer AGS cells.

aYAP1-2 contributes to bFGF-induced proliferation In gastric cancer

Gastric cancer (GC) is one of the leading causes of cancer-related deaths in humans worldwide. Fibroblast growth factor family (FGFs) and the Hippo signaling pathway play an important role in the epithelial-mesenchymal transition (EMT) process of GC. YAP1, a key mediator of the Hippo pathway, plays an important role in tumor genesis. Alternative splicing of human YAP1 mRNA results in two major isoforms: YAP1-1, which contains a single WW domain, and YAP1-2, which contains two WW domains, respectively. There are significant differences in post-transcriptional regulation and function. Basic FGF (bFGF) treatment promoted the EMT process of most GC cell lines, and the proliferation ability was enhanced. This process may be related to the upregulation of YAP1, the proliferation ability of GC was significantly alleviated upon YAP1 knockdown. bFGF treatment can induce EMT of GC through YAP1-2 and enhance their proliferative ability. In this process, bFGF may enhance the nuclear localization of YAP1-2.In the mouse model of intraperitoneal implantation tumorigenesis, it was shown that under the action of bFGF, the expressing YAP1-2 cell lines could form larger tumors than the expressing YAP1-1, but both of them were larger than the YAP1 knockdown. Our results show that YAP1-2 is the main subtype of bFGF-induced EMT and proliferation of GC cells.

Highly expressed B3GALT5-AS1 contributes to gastric cancer progression by recruiting WDR5 to mediate B3GALT5 and regulating β-catenin/ZEB1 axis

Long non-coding RNAs (lncRNAs) play an important role in the progression of gastric cancer (GC), but its specific regulatory mechanism remains to be further studied. We previously identified that lncRNA B3GALT5-AS1 was upregulated in GC serum. Here, we investigated the functions and molecular mechanisms of B3GALT5-AS1 in GC tumorigenesis. qRT-PCR was used to detect B3GALT5-AS1 expression in GC. EdU, CCK-8, and colony assays were utilized to assess the proliferation ability of B3GAL5-AS1, and transwell, tube formation assay were used to assess the invasion and metastasis ability. Mechanically, FISH and nuclear plasmolysis PCR identified the subcellular localization of B3GALT5-AS1. RIP and CHIP assays were used to analyse the regulation of B3GALT5-AS1 and B3GALT5. We observed that B3GALT5-AS1 was highly expressed in GC, and silencing B3GALT5-AS1 could inhibit the proliferation, invasion, and migratory capacities of GC. Additionally, B3GALT5-AS1 was bound to WDR5 and modulated the expression of B3GALT5 via regulating the ZEB1/β-catenin pathway. High-expressed B3AGLT5-AS1 promoted GC tumorigenesis and regulated B3GALT5 expression via recruiting WDR5. Our study is expected to provide a new idea for clinical diagnosis and treatment.

Exploring the Influence of T Cell Marker Gene Expression on the Pathobiology and Clinical Prognostic Outcomes in Intestinal-Type Gastric Carcinoma

BACKGROUND

Gastric cancer (GC) poses a significant global health challenge. This study is aimed at elucidating the role of the immune system, particularly T cells and their subtypes, in the pathogenesis and progression of intestinal-type gastric carcinoma (GC), and at evaluating the predictive utility of a T cell marker gene-based risk score for overall survival.

METHODS

We performed an extensive analysis using single-cell RNA sequencing data to map the diversity of immune cells and identify specific T cell marker genes within GC. Pseudotime trajectory analysis was employed to observe the expression patterns of tumor-related pathways and transcription factors (TFs) at various disease stages. We developed a risk score using data from The Cancer Genome Atlas (TCGA) as a training set and validated it with the GSE15459 dataset.

RESULTS

Our analysis revealed distinct patterns of T cell marker gene expression associated with different stages of GC. The risk score, based on these markers, successfully stratified patients into high-risk and low-risk groups with significantly different overall survival prospects. High-risk patients exhibited poorer survival outcomes compared to low-risk patients (p < 0.05). Additionally, the risk score was capable of identifying patients across a spectrum from chronic atrophic gastritis to early GC.

CONCLUSION

The findings enhance the understanding of the tumor immune microenvironment in GC and propose new immunotherapeutic targets. The T cell marker gene-based risk score offers a potential tool for gastroenterologists to tailor treatment plans more precisely according to the cancer's severity.

Human circular RNA hsa_circ_0000231 clinical diagnostic effectiveness as a new tumor marker in gastric cancer

BACKGROUND

Owing to the subtlety of initial symptoms associated with gastric cancer (GC), the majority of patients are diagnosed at later stages. Given the absence of reliable diagnostic markers, it is imperative to identify novel markers that exhibit high sensitivity and specificity. Circular RNA, a non-coding RNA, plays an important role in tumorigenesis and development and is well expressed in body fluids.

AIMS

In this study, we aimed to identify hsa_circ_0000231 as a new biomarker for the diagnosis of GC and to assess its clinical diagnostic value in serum.

METHODS AND RESULTS

The stability and correctness of hsa_circ_0000231 was determined by agarose gel electrophoresis, Rnase R assay and Sanger sequencing. Real-time quantitative polymerase chain reaction (qRT-PCR) was designed to discover the expression level of hsa_circ_0000231 and whether it has dynamic serum monitoring capability. The correlation between hsa_circ_0000231 and clinicopathological parameters was analyzed by collecting clinical and pathological data from GC patients. In addition, diagnostic efficacy was assessed by constructing receiver operating characteristic curves (ROC). Hsa_circ_0000231 exhibits a stable and consistently expressed structure. In GC serum, cells, and tissues, it demonstrates reduced expression levels. Elevated expression levels observed postoperatively suggest its potential for dynamic monitoring. Additionally its expression level correlates with TNM staging and neuro/vascular differentiation. The area under ROC curve (AUC) for hsa_circ_0000231 is 0.781, indicating its superior diagnostic value compared to CEA, CA19-9, and CA72-4. The combination of these four indicators enhances diagnostic accuracy, with an AUC of 0.833.

CONCLUSIONS

The stable expression of hsa_circ_0000231 in the serum of gastric cancer patients holds promise as a novel biomarker for both the diagnosis and dynamic monitoring of GC.

Salivary biomarkers for the diagnosis of gastric cancer: a systematic review

Background

Recent advancements reveal saliva as a crucial source of diagnostic biomarkers for various diseases, notably gastric cancer. This systematic review evaluates these biomarkers, emphasizing their clinical applicability and potential in early detection.

Methods

An extensive electronic search was conducted across PubMed/MEDLINE, Scopus, and Web of Science to identify relevant studies. Salivary biomarkers were analyzed as independent variables, with gastric cancer as the dependent variable. The study adhered to a protocol registered with PROSPERO (CRD42021259519).

Results

Our analysis identified a range of biomarkers, highlighting three proteins - cystatin-B (CSTB), triosephosphate isomerase (TPI1), and deleted in malignant brain tumors 1 protein (DMBT1) - as particularly accurate for gastric cancer diagnosis.

Conclusions

Salivary biomarkers hold substantial promise for the early detection of gastric cancer. Future research should aim to refine study design and validation for enhancing the quality and applicability of these biomarkers.

The role and function of autophagy through signaling and pathogenetic pathways and lncRNAs in ovarian cancer

Lysosomal-driven autophagy is a tightly controlled cellular catabolic process that breaks down and recycles broken or superfluous cell parts. It is involved in several illnesses, including cancer, and is essential in preserving cellular homeostasis. Autophagy prevents DNA mutation and cancer development by actively eliminating pro-oxidative mitochondria and protein aggregates from healthy cells. Oncosuppressor and oncogene gene mutations cause dysregulation of autophagy. Increased autophagy may offer cancer cells a pro-survival advantage when oxygen and nutrients are scarce and resistance to chemotherapy and radiation. This finding justifies the use of autophagy inhibitors in addition to anti-neoplastic treatments. Excessive autophagy levels can potentially kill cells. The diagnosis and treatment of ovarian cancer present many difficulties due to its complexity and heterogeneity. Understanding the role of autophagy, a cellular process involved in the breakdown and recycling of cellular components, in ovarian cancer has garnered increasing attention in recent years. Of particular note is the increasing amount of data indicating a close relationship between autophagy and ovarian cancer. Autophagy either promotes or restricts tumor growth in ovarian cancer. Dysregulation of autophagy signaling pathways in ovarian cancers can affect the development, metastasis, and response to tumor treatment. The precise mechanism underlying autophagy concerning ovarian cancer remains unclear, as does the role autophagy plays in ovarian carcinoma. In this review, we tried to encapsulate and evaluate current findings in investigating autophagy in ovarian cancer.

Chimeric Antigen Receptor-T Cell and Oncolytic Viral Therapies for Gastric Cancer and Peritoneal Carcinomatosis of Gastric Origin: Path to Improving Combination Strategies

Precision immune oncology capitalizes on identifying and targeting tumor-specific antigens to enhance anti-tumor immunity and improve the treatment outcomes of solid tumors. Gastric cancer (GC) is a molecularly heterogeneous disease where monoclonal antibodies against human epidermal growth factor receptor 2 (HER2), vascular endothelial growth factor (VEGF), and programmed cell death 1 (PD-1) combined with systemic chemotherapy have improved survival in patients with unresectable or metastatic GC. However, intratumoral molecular heterogeneity, variable molecular target expression, and loss of target expression have limited antibody use and the durability of response. Often immunogenically "cold" and diffusely spread throughout the peritoneum, GC peritoneal carcinomatosis (PC) is a particularly challenging, treatment-refractory entity for current systemic strategies. More adaptable immunotherapeutic approaches, such as oncolytic viruses (OVs) and chimeric antigen receptor (CAR) T cells, have emerged as promising GC and GCPC treatments that circumvent these challenges. In this study, we provide an up-to-date review of the pre-clinical and clinical efficacy of CAR T cell therapy for key primary antigen targets and provide a translational overview of the types, modifications, and mechanisms for OVs used against GC and GCPC. Finally, we present a novel, summary-based discussion on the potential synergistic interplay between OVs and CAR T cells to treat GCPC.

Identification of stromal cell-derived factor 4 as a liquid biopsy-based diagnostic marker in solid cancers

There is a need for serum diagnostic biomarkers to improve the prognosis of solid malignant tumors. Here, we conducted a single-institutional study to evaluate the diagnostic performance of serum stromal cell-derived factor 4 (SDF4) levels in cancer patients. Serum samples were collected from a total of 582 patients with solid cancers including gastric cancer (GC) and 80 healthy volunteers. SDF4 protein levels in sera, and conditioned media or lysates of human GC cell lines were measured by enzyme-linked immunosorbent assay, and those in GC tissue by immunohistochemistry. Serum SDF4 levels were higher in patients with cancer than the healthy control in all cancer type. Regarding GC, serum SDF4 levels distinguished healthy controls from GC patients with the area under the curve value of 0.973, sensitivity of 89%, and specificity of 99%. Serum SDF4 levels were significantly elevated in patient with early stage GC. In immunohistochemistry, the frequency of SDF4-positive GC tumors did not vary significantly between GC stages. The ability of human GC cell lines to both produce and secrete SDF4 was confirmed in vitro. In conclusion, serum SDF4 levels could be a promising candidate for a novel diagnostic biomarker for GC and other malignancies.

Predictors of survival outcomes among patients with gastric cancer in a leading tertiary, teaching and referral hospital in Kenya

INTRODUCTION

The incidence of gastrointestinal malignancies in Kenya is increasing, although there is a paucity of data on survival outcomes among gastric cancer patients. Hence, this study aimed to assess survival outcomes among adult gastric cancer patients at Kenyatta National Hospital.

METHODS

A retrospective cohort study design was used to assess the survival outcomes among 247 gastric cancer patients. All medical records of adult (≥18 years) gastric cancer patients with complete medical records of diagnosis, stage of cancer, and treatment regimen in the study setting in the last 5 years (2016-2020) were included. A simple random sampling technique was employed to select the study participants. Data were collected using a data abstraction tool composed of socio-demographic and clinical characteristics. Survival outcomes were reported as the percentage of mortality, mean survival estimate, and mean cancer-specific survival. The data were entered and analyzed using version 20.0 SPSS statistical software. The mean survival estimates and predictors of mortality were computed using the Kaplan-Meier and Cox regression analysis.

RESULTS

The study showed that 33.3% (64) had new distant metastasis, and 42.1% (104) had disease progression. Besides, the mortality rate was high (33.6%), and 14.6% and 7.7% of patients had complete and partial responses, respectively. The five-year survival was 32.7% among gastric cancer patients. Comorbidity (p = 0.014), advanced-stage diseases (p = 0.03), chemotherapy (p = 0.008), and gastrectomy (p = 0.016) were significant determinants of mortality.

CONCLUSIONS

A significant proportion of patients had distant metastasis, disease progression, and a low five-year survival rate. Hence, early cancer-screening programs are indispensable to circumvent disease progression and improve survival outcomes.

Overexpression of lncRNA TCLlnc1 in gastric cancer predicts postoperative distant recurrence and poor survival

TCLlnc1 was characterized as a lncRNA with oncogenic roles in T cell lymphoma, whereas its role in other diseases is unknown. We then explored the involvement of TCLlnc1 in gastric cancer. Paired gastric cancer and nontumor tissues from 66 gastric cancer patients were used to extract total RNA samples, which were used to perform RT-qPCRs to determine the expression of TCLlnc1. Plasma samples from these 66 gastric cancer patients and 66 healthy controls were also used to detect circulating TCLlnc1. Correlations of TCLlnc1 in both plasma and tissue samples with patients’ clinical data were analyzed by chi-square t-test. The diagnostic value of TCLlnc1 for early-stage gastric cancer was analyzed with the receiver operating characteristic curve. A 5-year follow-up study was performed to explore the prognostic value of TCLlnc1 for the survival of gastric cancer patients. TCLlnc1 expression in tissue was increased in gastric cancer. Plasma TCLlnc1 was also increased in gastric cancer. Plasma TCLlnc1 was closely correlated with TCLlnc1 in gastric cancer tissues, but not TCLlnc1 in nontumor tissues. TCLlnc1 in plasma was only correlated with tumor distant metastasis, but not other clinical data. TCLlnc1 in plasma showed promising diagnostic value for stage I and II gastric cancer. Increased accumulation of TCLlnc1 was closely correlated with distant recurrence and poor survival during a 5-year follow-up. Therefore, TCLlnc1 is overexpressed in gastric cancer predicts postoperative distant recurrence and poor survival.

Molecular and Circulating Biomarkers of Gastric Cancer

Gastric cancer (GC)—a common tumor that affects humans worldwide—is highly malignant with a poor prognosis. GC is frequently not diagnosed until a relatively advanced stage. Early detection and efficient monitoring of tumor dynamics are prerequisites for reducing disease burden and mortality. Minimally invasive methods are needed to establish a diagnosis or monitoring the response to treatment of gastric cancer. Blood-based biomarker assays for the detection of early-stage GC could be of great relevance both for the risk group or for population-wide based screening programs, The currently used tumor marker assays for detecting GC are simple and rapid, but their use is limited by their low sensitivity and specificity. In recent years, several markers have been identified and tested for their clinical relevance in the management of gastric cancer. Here we review the available literature on plasma classical tumor markers, circulating free microRNAs (cfmiRNAs), circulating cell-free DNA (cfDNA), circulating tumor cells (CTCs), autoantibodies against tumor associated antigens (TAAs), and circulating extracellular vesicles (EVs) for diagnosis and monitoring of gastric cancer. This review summarizes the present status and approaches for these biomarkers, which could be potentially used for early diagnosis and accurate prediction of therapeutic approaches. We also discuss the future perspective and challenges in the search for new biomarkers of gastric cancer.

Integrated Bioinformatics Analysis for Identifying the Significant Genes as Poor Prognostic Markers in Gastric Adenocarcinoma

Gastric adenocarcinoma (GAC) is the most common histological type of gastric cancer and imposes a considerable health burden globally. The purpose of this study was to identify significant genes and key pathways participated in the initiation and progression of GAC. Four datasets (GSE13911, GSE19826, GSE54129, and GSE79973) including 171 GAC and 77 normal tissues from Gene Expression Omnibus (GEO) database were collected and analyzed. Through integrated bioinformatics analysis, we obtained 69 commonly differentially expressed genes (DEGs) among the four datasets, including 20 upregulated and 49 downregulated genes. The prime module in protein-protein interaction network of DEGs, including ADAMTS2, COL10A1, COL1A1, COL1A2, COL8A1, BGN, and SPP1, was enriched in protein digestion and absorption, ECM-receptor interaction, focal adhesion, PI3K-Akt signaling pathway, and amoebiasis. Furthermore, expression and survival analysis found that all seven hub genes were highly expressed in GAC tissues and 6 of them (except for SPP1) were able to predict poor prognosis of GAC. Finally, we verified the 6 high-expressed hub genes in GAC tissues via immunohistochemistry, Western blot, and RNA quantification analysis. Altogether, we identified six significantly upregulated DEGs as poor prognostic markers in GAC based on integrated bioinformatical methods, which could be potential molecular markers and therapeutic targets for GAC patients.

Transcriptomic profiling of single circulating tumor cells provides insight into human metastatic gastric cancer

Transcriptome analysis of circulating tumor cells (CTCs), which migrate into blood vessels from primary tumor tissues, at the single-cell level offers critical insights into the biology of metastasis and contributes to drug discovery. However, transcriptome analysis of single CTCs has only been reported for a limited number of cancer types, such as multiple myeloma, breast, hepatocellular, and prostate cancer. Herein, we report the transcriptome analysis of gastric cancer single-CTCs. We utilized an antigen-independent strategy for CTC isolation from metastatic gastric cancer patients involving a size-dependent recovery of CTCs and a single cell isolation technique. The transcriptomic profile of single-CTCs revealed that a majority of gastric CTCs had undergone epithelial-mesenchymal transition (EMT), and indicated the contribution of platelet adhesion toward EMT progression and acquisition of chemoresistance. Taken together, this study serves to employ CTC characterization to elucidate the mechanisms of chemoresistance and metastasis in gastric cancer.

Diagnostic value of exosome derived long noncoding RNA in gastric cancer in Chinese population: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Objective to systematically evaluate the diagnostic value of long noncoding RNA (lncRNA) in gastric cancer (GC) in the Chinese population.

METHODS

PubMed, Web of Science, EMBASE, Cochrane Library, CNKI, and Wanfang Database were searched. According to the search strategy and inclusion and exclusion criteria, 2 staff members screened the relevant kinds of literature from January 2010 to December 2020 and extracted the relevant data. Revman5.3, Meta-Disc1.4, and Stata15.1 software were used to analyze the relationship between lncRNA from exosomes and the diagnosis of GC. The combined values of sensitivity (SEN), specificity (SPE), positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio (DOR) and their corresponding 95% confidence intervals (CIs) were calculated. The summary receiver operating characteristic curve was drawn and the area under the ROC curve (AUC) value was calculated.

RESULTS

In 9 studies, 1314 samples were included, including 792 cases in the case group and 522 cases in the control group. The combined SEN was 0.82 (95% CI: 0.77-0.86), the combined SPE was 0.78 (95% CI: 0.72-0.83), the combined positive likelihood ratio was 3.7 (95% CI: 2.9-4.6), the negative likelihood ratio was 0.23 (95% CI: 0.18-0.29), and the DOR was 16 (95% CI: 12-23), AUC was 0.87 (95% CI: 0.84-0.90). Subgroup analysis showed that the SEN, SPE, likelihood ratio, DOR, and AUC of plasma-derived lncRNA in the diagnosis of GC were better than those of serum.

CONCLUSIONS

Exosome-derived lncRNA may be a new potential biomarker for the clinical diagnosis of GC.

Bioinformatic Analysis Identified Potentially Prognostic Long Noncoding RNAs and MicroRNAs for Gastric Cancer

Gastric cancer (GC) is the fifth most common malignant tumor in the world. The present study was performed to discover the potential diagnostic and therapeutic long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) of GC. Data used in this study to identify differentially expressed lncRNAs (DElncRNAs) and miRNAs (DEmiRNAs) were obtained from 187 GC tissues and 32 adjacent nontumor tissues. The total clinical data on GC included 187 cases. The above data were from the TCGA database. RStudio/Bioconductor software was used to conduct univariate analysis, the least absolute shrinkage and selection operator (LASSO) Cox, and multivariate Cox proportional risk regression for the DElncRNAs and DEmiRNAs. Clinical information was analyzed through univariate and multivariate Cox analysis. Results: five lncRNAs (AC007785.3, AC079385.3, LINC00392, LINC01729, and U95743.1) and two miRNAs (hsa-miR-3174, hsa-miR-605) were proven to be independent prognostic indicators of GC. Results of the Kaplan-Meier survival analysis showed that AC007785.3, AC079385.3, LINC01729, miR-3174, and miR-605 were significantly correlated with OS of GC. The target genes of AC079385.3, miR-3174, and miR-605 were obtained and clustered mainly on MAPK and cGMP-PKG signaling pathways. The clinical data showed that age and clinicopathologic stage were correlated with the prognosis of GC. Furthermore, AC007785.3 was associated with metastasis of GC, and miR-3174 was associated with the primary tumor condition of GC. We identified three lncRNAs (AC007785.3, AC079385.3, LINC01729), two miRNAs (miR-3174, miR-605), and clinical factors related to the pathogenesis and prognosis of GC. Our predicted results provide a possible entry point for the study of prognostic markers for GC.

Serum Dihydropyrimidinase-Like 3 Concentration in Patients with Gastric Cancer and Its Diagnostic Value

Background:

We aimed to investigate the serum concentration of dihydropyrimidinase-like 3 (DPYSL3) in patients with gastric cancer and its clinical significance.

Methods:

Seventy four patients with gastric cancer from Wuhan Central Hospital, Tongji Medical College, Huazhong University of Science and Technology, China from October 2018 to April 2019 were selected as the case group. Sixty patients with normal gastric mucosa or mild non-atrophic gastritis were selected as the control group. Serum DPYSL3, CA72-4 and CEA concentrations were measured in both groups.

Results:

The serum DPYSL3 concentration in the case group was significantly higher than that in the healthy control group (22.04±9.22 vs. 8.36±4.19 μg/L, P<0.001). The serum DPYSL3 concentration in patients with advanced gastric cancer was significantly higher than that in early gastric cancer (27.09±9.12 vs. 13.04±8.22 μg/L, P<0.01); serum DPYSL3 concentration was significantly correlated with tumor size, TNM stage and differentiation (P<0.05). When the cutoff value was 20.98 μg/L, the serum DPYSL3 concentration could differentiate the gastric cancer with ROC^AUC 0.882 (95% CI: 0.828–0.937) with sensitivity and specificity of 75% and 94%, respectively. Serum CA72-4 concentration could differentiate the gastric cancer from health controls with ROC^AUC 0.812 (95% CI: 0.734–0.834), serum CEA concentration could differentiate gastric cancer with ROC^AUC 0.612 (95% CI: 0.534 ∼ 0.634). The serum concentrations of DPYSL3, CA72-4 and CEA in gastric cancer patients were increased compared to health controls.

Conclusion:

Three serological markers have complementary diagnostic value for gastric cancer. Serum DPYSL3 is a new potential molecular marker for gastric cancer.

Curcumin suppresses the progression of gastric cancer by regulating circ_0056618/miR-194-5p axis

Curcumin has been demonstrated to be an anti-tumor agent in many types of cancers, including gastric cancer (GC). However, the molecular mechanisms by which curcumin performs its anti-tumor effects remain elusive. circ_0056618 and miR-194-5p are reported to be involved in GC progression, but their relationships with curcumin are unclear. In this study, circ_0056618 was elevated, and miR-194-5p was reduced in GC tissues and cells. Curcumin treatment led to a decrease in circ_0056618 level in GC cells. Overexpression of circ_0056618 promoted cell proliferation, migration, and invasion and suppressed cell cycle arrest and apoptosis in curcumin-treated GC cells. Moreover, miR-194-5p was identified as the target of circ_0056618, and its expression in GC cells increased after curcumin treatment. Overexpression of miR-194-5p reversed the promotional effect of circ_0056618 on cell progression in curcumin-treated GC cells. Additionally, curcumin treatment repressed the tumorigenesis of GC in vivo through regulating circ_0056618. Curcumin treatment delayed the development of GC partly through decreasing circ_0056618 and increasing miR-194-5p.

STRA6 Expression Serves as a Prognostic Biomarker of Gastric Cancer

BACKGROUND

Despite advances in our understanding on the pathogenesis of gastric cancer (GC), patients face a poor prognosis. To improve clinical outcomes, effective approaches to diagnosis and treatment employing new diagnostic biomarkers are required to achieve early detection and predict recurrence and prognosis.

MATERIALS AND METHODS

Transcriptome analysis was conducted using surgically resected gastric tissues from four patients with metastatic GC. A total of 228 pairs of primary GC tissues and corresponding normal adjacent tissues were subjected to mRNA expression analysis. To validate our findings, we accessed an integrated microarray dataset and RNA sequencing data of GC cell lines.

RESULTS

We identified stimulated by retinoic acid 6 (STRA6) as a differentially overexpressed gene, which encodes a transmembrane protein that mediates the cellular uptake of retinol. To investigate how STRA6 contributes to the malignant phenotype of GC cells, we mined public datasets and found the mRNA encoding retinol binding protein 1 (RBP1), which is associated with retinoid metabolism, was co-expressed with STRA6. Furthermore, STRA6 mRNA levels were significantly higher in GC tissues compared to the corresponding noncancerous adjacent tissues of 228 surgically resected gastric tissue samples. Moreover, patients with high levels of STRA6 mRNA experienced significantly shorter disease-free survival and overall survival. Multivariate analysis revealed that high levels of STRA6 served as a significant risk factor.

CONCLUSION

Patients with high levels of STRA6 mRNA experienced significantly worse clinical outcomes, indicating that STRA6 may serve as a diagnostic and prognostic biomarker of GC.

SFRP4 drives invasion in gastric cancer and is an early predictor of recurrence

OBJECTIVE

Gastric cancer patients generally have a poor outcome, particularly those with advanced-stage disease which is defined by the increased invasion of cancer locally and is associated with higher metastatic potential. This study aimed to identify genes that were functional in the most fundamental hallmark of cancer, namely invasion. We then wanted to assess their value as biomarkers of gastric cancer progression and recurrence.

DESIGN

Data from a cohort of patients profiled on cDNA expression arrays was interrogated using K-means analysis. This genomic approach classified the data based on patterns of gene expression allowing the identification of the genes most correlated with the invasion of GC. We evaluated the functional role of a key protein from this analysis in invasion and as a biomarker of recurrence after curative resection.

RESULTS

Expression of secreted frizzled-related protein 4 (SFRP4) was identified as directly proportional to gastric cancer invasion. This finding was validated in multiple, independent datasets and its functional role in invasion was also confirmed using invasion assays. A change in serum levels of SFRP4 after curative resection, when coupled with AJCC stage, can accurately predict the risk of disease recurrence after curative therapy in an assay we termed PredictR.

CONCLUSIONS

This simple ELISA-based assay can help predict recurrence of disease after curative gastric cancer surgery irrespective of adjuvant therapy. The results require further evaluation in a prospective trial but would help in the rational prescription of cancer therapies and surveillance to prevent under or over treatment of patients after curative resection.

The prediction of survival in Gastric Cancer based on a Robust 13-Gene Signature

Gastric cancer represents a major public health problem. Owing to the great heterogeneity of GC, conventional clinical characteristics are limited in the accurate prediction of individual outcomes and survival. This study aimed to establish a robust gene signature to predict the prognosis of GC based on multiple datasets. Initially, we downloaded raw data from four independent datasets of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO), and performed univariate Cox proportional hazards regression analysis to identify prognostic genes associated with overall survival (OS) from each dataset. Thirteen common genes from four datasets were screened as candidate prognostic signatures. Then, a risk score model was developed based on this 13‑gene signature and validated by four independent datasets and the entire cohort. Patients with a high-risk score had poorer OS and recurrence-free survival (RFS). Multivariate regression and stratified analysis revealed that the 13-gene signature was not only an independent predictive factor but also associated with recurrence when adjusting for other clinical factors. Furthermore, in the high-risk group, gene set enrichment analysis (GSEA) showed that the mTOR signaling pathway and MAPK signaling pathway were significantly enriched. The present study provided a robust and reliable gene signature for prognostic prediction of both OS and RFS of patients with GC, which may be useful for delivering individualized management of patients.

Diagnostic and Prognostic Characteristics of Circulating Free DNA Methylation Detected by the Electrochemical Method in Malignant Tumors

Simple Summary

Previous studies have established an electrochemical detection method for the rapid detection of cfDNA (circulating free DNA) methylation and found that this technology might be a potential method for cancer diagnosis. However, the underlying mechanism and its role in the diagnosis and prognosis of malignant tumors are not well-characterized. In present study, we utilized the electrochemical detection method to detect the DNA methylation status by using electron microscopies and infrared spectroscopy and found that DNA with different methylated levels adsorbed to the gold surface differently, which was likely mediated by hydrophobic bonds. In addition, after detection of the cfDNA methylation status from 505 normal individuals, 725 cancer patients before treatment, and 549 patients after treatment, we found that the cfDNA adsorption rate could be used as an indicator for the diagnosis and prognosis prediction of pan-cancer. Our research provides a novel method for the liquid biopsy of cancer for diagnosis and prognosis predictions.

Abstract

Prior research has established an electrochemical method based on the differential adsorption capacity of gold surfaces with different methylated DNA degrees and found that this method might be valuable for cancer diagnosis by detecting circulating free DNA methylation. However, further investigation on the underlying mechanism and validation of its diagnostic and prognostic values in a large cohort of malignant tumors was limited. We found that DNA with different methylation levels formed particles of diverse sizes on the gold surface. Hydrophobic bonds played a significant role in the binding process of methylated DNA to the gold surface. The detection condition of an adsorption time of 10 min and temperature of 20 °C was optimal. In a large cohort of plasma samples from the patients with different malignant tumors, as well as normal individuals, we found that the electrochemical detection method based on the differential adsorption capacity of methylated DNA degree on a gold surface could be used as a noninvasive tool for malignant tumor diagnosis and prognostic evaluation. The diagnostic efficiency of this method in malignant tumors was even slightly better than that of the current tumor biomarkers widely used in routine clinical practice (circulating free DNA (cfDNA) vs. carcinoembryonic antigen (CEA), 0.8131 vs. 0.7191 and cfDNA vs. CA19-9, 0.7687 vs. 0.6693).

Prognostic value of microRNA-125a/b family in patients with gastric cancer: a meta-analysis

AIM

This meta-analysis was designed to reassess the prognostic and clinicopathologic values of the microRNA-125 family in GC patients.

BACKGROUND

The miR-125 family (including miR-125a, miR-125b) has been reported as being pivotal prognostic biomarkers of gastric cancer (GC). However, there is controversy about the role of the miR-125 family in predicting the progression of GC.

METHODS

The miR-125 family (including miR-125a, miR-125b) has been reported as being pivotal prognostic biomarkers of gastric cancer (GC). However, there is controversy about the role of the miR-125 family in predicting the progression of GC.

RESULTS

The electronic databases of PubMed, ISI Web of Science, Scopus, and Cochrane Library were systematically searched for relevant studies. Overall survival (OS) rate as the primary outcome from each study was extracted. The overall hazard ratio (HR or survival rate in patients with GC) and odds ratio (OR) with 95% confidence interval (CI) was calculated to evaluate the association between miR-125 family expression and prognosis and susceptibility to gastric cancer. The quality of evidence was evaluated using the Newcastle-Ottava Scale (NOS). The extracted data was combined based on the random-effects model.

CONCLUSION

The low expression of miR-125 family predicts poor OS in GC patients. Thus, the miR-125 family may be helpful as a potential biomarker for the prognosis of gastric cancer.

Correlation between tumor marker CA72-4 and prognosis of patients with gastric cancer: A protocol for systematic review and meta-analysis

BACKGROUND

Gastric cancer is one of the common gastrointestinal tumors, with high recurrence and metastasis rates. Tumor marker tumor marker carbohydrate antigen 72-4 (CA72-4) has been used in the screening and diagnosis of gastric cancer, but whether it can be used as an indicator to monitor the prognosis of gastric cancer remains a great controversy. The purpose of this study was to systematically evaluate the correlation between tumor marker CA72-4 and prognosis of gastric cancer patients.

METHODS

A systematic search was performed by retrieving on English databases (PubMed, Embase, Web of Science, the Cochrane Library) and Chinese databases (China Knowledge Network, Wanfang, Weipu (VIP Information Chinese Journal Service Platform), CBM) of clinical study on the correlation between tumor marker CA72-4 and prognosis of gastric cancer patients. The retrieval time limit was from the establishment of the database to October 2020. Two researchers independently extracted and evaluated the quality of the data in the included study. A meta-analysis was performed using Stata12.0 and RevMan5.3 software.

CONCLUSIONS

This study will compare the correlation between tumor marker CA72-4 and prognosis of gastric cancer patients, so as to provide evidence-based basis for clinicians to select prognostic indicators of gastric cancer.

ETHICS AND DISSEMINATION

Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval was not required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences.

OSF REGISTRATION NUMBER

DOI: 10.17605 / OSF.IO / B3AMN.

AT-rich interactive domain1A determines sensitivity to oxaliplatin in gastric cancer cells

Background

Gastric cancer is a highly heterogeneous disease and its traditional histopathological classification is difficult to meet clinical needs. Oxaliplatin is an antitumor drug with high efficiency and low toxicity. Therefore, the insensitivity or secondary drug resistance of oxaliplatin to gastric cancer is vital for tumor progression. The aim of this study was to investigate the sensitivity of gastric cancer cells to oxaliplatin after ARID1A (AT-rich interactive domain1A gene) gene silencing.

Methods

MGC-803 and AGS cells were selected as gastric cancer cells for study. ARID1A protein and mRNA expression was detected by Western blot and quantitative reverse-transcription PCR (qRT-PCR). The short hairpin RNA (shRNA) fragment of ARID1A gene silencing was constructed and introduced into gastric cancer cells. The cell proliferation activity was calculated using CCK8 and the IC50 was calculated. The flow cytometry was used to detect the cell cycle and apoptosis rate. The ability of cell invasion was detected by transwell method. Cells were treated with different concentrations of oxaliplatin.

Results

The proliferation of gastric cancer cells was promoted by ARID1A gene silencing (P<0.01), the quantity of cells in S phase increased (P<0.05), and the invasive ability increased (P<0.05). After treatment with oxaliplatin at different concentrations, ARID1A gene silencing reduced the inhibition rate of oxaliplatin on gastric cancer cells and apoptosis rate (P<0.05), and increased IC 50 (P<0.01).

Conclusions

ARID1A gene silencing, a factor promoting proliferation of gastric cancer cells, would reduce the sensitivity of gastric cancer cells to oxaliplatin, which can provide a basis for the exploration of targeted drugs for individualized treatment of gastric cancer.

Application of artificial neural networks in detection and diagnosis of gastrointestinal and liver tumors

As a form of artificial intelligence, artificial neural networks (ANNs) have the advantages of adaptability, parallel processing capabilities, and non-linear processing. They have been widely used in the early detection and diagnosis of tumors. In this article, we introduce the development, working principle, and characteristics of ANNs and review the research progress on the application of ANNs in the detection and diagnosis of gastrointestinal and liver tumors.

Expression of ASAP1 and FAK in gastric cancer and its clinicopathological significance

The present study aimed to analyze the expression levels of adenosine diphosphate ribosylation factor guanylate kinase 1 (ASAP1) and focal adhesion kinase (FAK) in gastric cancer (GC) tissues in order to explore their association with clinicopathological features and prognosis. A total of 32 patients with GC were enrolled in the present study. All patients had complete clinical follow-up data and paraffin-embedded normal gastric mucosal tissues. The expression levels of ASAP1 and FAK in these tissues were measured by immunohistochemistry. The associations of ASAP1 and FAK expression with clinicopathological factors and the survival of patients with GC were subsequently analyzed. The expression levels of ASAP1 (59.4%) and FAK (68.8%) in GC tissues were significantly higher than those in normal gastric mucosal tissues (28.1 and 40.6%, P<0.05). The expression levels of ASAP1 and FAK were associated with depth of invasion, lymph node metastasis and pathological stage (P<0.05). ASAP1 expression was positively associated with FAK expression (P<0.001). In addition, ASAP1 and FAK expression levels were negatively associated with disease-free survival time and overall survival time (P<0.05). The 5-year overall survival rate was significantly higher in patients with negative ASAP1 or FAK expression compared with that in patients with positive ASAP1 or FAK expression (P<0.05). In conclusion, ASAP1 and FAK were highly expressed in human GC tissues and may serve a synergistic role in promoting tumorigenesis, progression, invasion and metastasis in patients with GC. ASAP1 and FAK expression in GC were associated with patient's survival. Therefore, ASAP1 and FAK may represent novel molecular markers for the pathophysiology and prognosis of GC.

The impact of negative lymph nodes in the survival outcomes of pN+ patients following radical gastrectomy: the inverse lymph node ratio as a better score to study negative lymph nodes

The impact of negative lymph nodes (LNs) on survival of pN+ patients has been recognized. The weight of negative LNs in an inverse lymph node ratio (nR) should be related to its prognostic impact. Five hundred and two consecutive gastric cancer patients, who underwent radical gastrectomy, were included. Patients were split into groups according to the number of harvested nodes and a cross-tabulation with pTNM stages was performed to test differences in the tumor burden. pN+ patients (n = 296) were split into groups of negative LNs harvested. We tested an alternative formula for computing a lymph node ratio: nR = total number of harvested nodes/total number of positive nodes. The median number of negative LNs was significantly different (p < 0.01) between dissection groups, but not the median of positive nodes (p > 0.05). No difference in pTNM percentage distribution was found between these groups (p > 0.05). When tested, the overall survival improved significantly for groups with larger numbers of negative LNs (p < 0.001). A cutoff of nR ≥ 6 was an independent prognostic factor for survival (p = 0.001), and the survival of pN+ patients with nR ≥ 6 was not different from pN0 patients. The impact of the number of negative LNs on the survival of the pN+ patients was demonstrated. The higher numbers in the numerator of the nR was due to the disproportion between harvested negative LNs and metastatic LNs. Larger ratios imply more negative lymph nodes in relation to positive lymph nodes, which was significantly associated with survival. We believe that the proposed nR is a friendlier to use format because of its intuitive interpretation.

Evaluating the diagnostic and prognostic value of serum long non-coding RNA CTC-497E21.4 in gastric cancer

Background Long non-coding RNAs (lncRNAs) have been reported to play a key role in gastric cancer (GC) tumorigenesis. However, the clinical application value of serum lncRNAs in GC has remained largely unknown. We investigated the role of a novel lncRNA named CTC-497E21.4 in the diagnosis and the prognosis of GC. Methods We focused on evaluation of lncRNA CTC-497E21.4 by real-time fluorescent quantitative polymerase chain reaction (RTFQ-PCR). The study involved following aspects: (1) confirmation of the higher lncRNA CTC-497E21.4 expression in different types of GC specimens than corresponding controls; (2) evaluation of monitoring tumor dynamics by the serum lncRNA CTC-497E21.4 assay; (3) evaluation of the prognostic value of lncRNA CTC-497E21.4 assay in GC. Results (1) The method of RTFQ-PCR detection of lncRNA CTC-497E21.4 was evaluated to have high sensitivity and specificity. (2) The expression levels of lncRNA CTC-497E21.4 were higher in GC patients compared with corresponding controls (p<0.001), and the combination of serum lncRNA CTC-497E21.4, CEA and CA19-9 could improve diagnostic sensitivity (96.36%). (3) The serum lncRNA CTC-497E21.4 expression levels were lower in postoperative samples than preoperative samples (p=0.0021) and survival curves downloaded from TCGA showed high lncRNA CTC-497E21.4 levels were associated with poor OS of GC (p=0.0351). Conclusions lncRNA CTC-497E21.4 may be a potential biomarker for the diagnosis and the prognosis of GC.

Association of APC gene promoter methylation and the risk of gastric cancer: A meta-analysis and bioinformatics study

BACKGROUND

The methylation status of the adenomatous polyposis coli (APC) promoter has been shown to be associated with the occurrence of gastric cancer, but this finding remains controversial. The aim of this study was to investigate the relationship between methylation of the APC gene promoter and gastric cancer.

METHODS

We searched the Web of Science, EMBASE, Medline, and Cochrane Central Register of Controlled Trials (CENTRAL) databases from the date of creation until August 1, 2019. According to the inclusion criteria, the relationship between the methylation status of the APC gene promoter and gastric cancer was investigated. The incidence of APC promoter methylation in the tissues or blood of patients with and without gastric cancer was compared. The results are expressed as the odds ratio (OR) and 95% confidence interval (CI). The pooled OR of each study was estimated using a fixed effects model or a random effects model to generate forest plots. We further validated the results using the MethHC database.

RESULTS

Eight studies (985 samples) were included. Our meta-analysis showed that the incidence of APC promoter methylation in patients with gastric cancer was higher than that of patients without gastric cancer (OR = 3.86, 95% CI 1.71-8.74, P = .001). Methylation of the APC promoter is associated with the incidence of gastric cancer, and it increases the risk of gastric cancer.

CONCLUSION

This study provides a new strategic direction for research on gastric cancer. Methylation of the APC promoter may be a potential biomarker for the diagnosis of gastric cancer, but the results of this work require further confirmation.

Serum levels of ANOS1 serve as a diagnostic biomarker of gastric cancer: a prospective multicenter observational study

BACKGROUND

Development of high-performance serum biomarkers will likely improve treatment outcomes of patients with gastric cancer (GC). We previously identified the candidate serum markers, anosmin 1 (ANOS1), dihydropyrimidinase-like 3 (DPYSL3), and melanoma-associated antigen D2 (MAGE-D2) and evaluated their clinical significance through a single-center retrospective analysis. Here we conducted a prospective multicenter observational study aimed at validating the diagnostic performance of these potential markers.

METHODS

We analyzed serum levels before and after surgery of the three potential biomarkers in patients with GC and healthy volunteers. Quantification of serum and GC tissue levels was performed using an ELISA.

RESULTS

Area under the curve (AUC) values that discriminated patients with GC from healthy controls were - 0.7058, 0.6188, and 0.5031 for ANOS1, DPYSL3, and MAGED2, respectively. The sensitivity and specificity of the ANOS1 assay were 0.36 and 0.85, respectively. The AUC value of ANOS1 that discriminated patients with stage I GC from healthy controls was 0.7131. Serum ANOS1 levels were significantly elevated in patients with stage I GC compared with those of healthy controls (median 1179 ng/ml and 461 ng/ml, respectively, P < 0.0001) and decreased after resection of primary GC lesions (P < 0.0001). The combination of serum ANOS1 and DPYSL3 levels increased the AUC value that discriminated patients with GC from healthy controls. Serum levels of ANOS1 did not significantly correlate with those of carcinoembryonic antigen, carbohydrate antigen 19-9, or other markers of inflammation.

CONCLUSIONS

Serum levels of ANOS1 may serve as a useful diagnostic tool for managing GC.

Prediction of gastric cancer prognosis in the next-generation sequencing era

Gastric cancer (GC) is one of the most commonly diagnosed malignancies worldwide, and is caused by complex interactions of multiple risk factors such as environmental (Helicobacter pylori and Epstein–Barr Virus), hereditary (genetic alterations and epigenetic modifications), as well as dietary and lifestyle factors. GC is usually detected at an advanced stage, with a dismal prognosis. Even for patients with similar clinical or pathologic stage receiving similar treatment, the outcomes are still uneven and unpredictable. To better incorporate genetic and epigenetic profiles into GC prognostic predication, gene expression signatures have been developed to predict GC outcomes. More recently, the advancement of high-throughput sequencing technology, also known as next-generation sequencing (NGS) technology, and analysis has provided the basis for accurate molecular classification of GC tumors. Here, we summarized and updated the literature related to NGS studies of GC, including whole-genome sequencing, whole-exome sequencing, RNA sequencing, and targeted sequencing, and discussed current progresses. NGS has facilitated the identification of genetic/epigenetic targets for screening as well as development of targeted agent therapy, thus enabling individualized patient management and treatment.

hnRNPK promotes gastric tumorigenesis through regulating CD44E alternative splicing

Background

The high prevalence of alternative splicing among genes implies the importance of genomic complexity in regulating normal physiological processes and diseases such as gastric cancer (GC). The standard form of stem cell marker CD44 (CD44S) and its alternatives with additional exons are reported to play important roles in multiple types of tumors, but the regulation mechanism of CD44 alternative splicing is not fully understood.

Methods

Here the expression of hnRNPK was analyzed among the Cancer Genome Atlas (TCGA) cohort of GC. The function of hnRNPK in GC cells was analyzed and its downstream targeted gene was identified by chromatin immunoprecipitation and dual luciferase report assay. Finally, effect of hnRNPK and its downstream splicing regulator on CD44 alternative splicing was investigated.

Results

The expression of hnRNPK was significantly increased in GC and its upregulation was associated with tumor stage and metastasis. Loss-of-function studies found that hnRNPK could promote GC cell proliferation, migration, and invasion. The upregulation of hnRNPK activates the expression of the splicing regulator SRSF1 by binding to the first motif upstream the start codon (- 65 to - 77 site), thereby increasing splicing activity and expression of an oncogenic CD44 isoform, CD44E (has additional variant exons 8 to 10, CD44v8-v10).

Conclusion

These findings revealed the importance of the hnRNPK-SRSF1-CD44E axis in promoting gastric tumorigenesis.

Nesfatin-1 is a potential diagnostic biomarker for gastric cancer

The lack of reliable plasma biomarkers limits their use in the diagnosis of gastric cancer (GC). The current study aimed to determine whether plasma nesfatin-1 can be used as a novel non-invasive biomarker for the diagnosis of GC. The levels of nesfatin-1 in 40 patients with GC and 40 healthy individuals, who were selected from the Chaohu Hospital Affiliated to Anhui Medical University, were assessed. ELISA was used for the measurement of plasma nesfatin-1 levels, while immunohistochemistry was applied to determine Ki67 protein expression in GC and normal gastric tissues. The diagnostic value of plasma nesfatin-1 for GC was further assessed using receiver operating characteristic (ROC) curve analysis. The results revealed that, compared with the controls, the mean nesfatin-1 levels in patients with GC were significantly increased. Furthermore, the protein expression of Ki67 in GC tissue was significantly upregulated compared with that in normal gastric tissue. Plasma nesfatin-1 levels were also demonstrated to be correlated with Ki67 protein expression in GC tissues. Additionally, ROC curve analysis indicated the potential diagnostic value of nesfatin-1, and the area under the ROC curve (AUC) for nesfatin-1 was 0.857 (95% confidence interval, 0.769-0.946). At a threshold nesfatin-1 level of 1.075 ng/ml, the optimal sensitivity and specificity were 70.0 and 95.0%, respectively, in discriminating patients with GC from healthy controls. These results indicated that plasma nesfatin-1 may serve as a novel biomarker for the diagnosis of GC and determination of GC cell proliferation.

Overexpression of PSMA7 predicts poor prognosis in patients with gastric cancer

Gastric cancer (GC) is the fourth most common tumor and the second most common cause of cancer-associated mortality worldwide. Current tumor biomarkers for GC, such as serum carcinoembryonic antigen and carbohydrate antigen 19-9, are not ideal due to their limited role as prognostic indicators for GC. Proteasome subunit α7 (PSMA7) is a multifunctional protein, which has been revealed to be involved in the development and progression of various types of malignancy. However, little is known about the role of PSMA7 in GC. In the present study, PSMA7 was identified to be overexpressed at the mRNA and protein levels in GC tissues, compared with in non-tumor tissues, using reverse transcription-quantitative PCR and immunohistochemistry. Furthermore, PSMA7 expression is associated with tumor invasion, lymph node metastasis, distant metastasis, and Tumor-Node-Metastasis stage. Univariate and multivariate Cox regression analysis identified that PSMA7 expression is an independent prognostic factor for poor survival. Kaplan-Meier survival curves revealed that high PSMA7 expression is associated with a poor prognosis in patients with GC. Overall, the results of the present study suggested that PSMA7 may be a promising biomarker for the prognosis of GC, and may represent a new diagnostic marker and molecular therapeutic target for GC.

STAMBPL1 knockdown has antitumour effects on gastric cancer biological activities

The present study aimed to investigate the effects and mechanisms of STAM binding protein-like 1 (STAMBPL1) knockdown in the suppression of gastric cancer activities. Pathological data and STAMBPL1 protein expression were analysed in 36 patients with gastric cancer, including 24 stage I-II and 12 stage III-IV patients, by haematoxylin and eosin staining and immunohistochemistry. In vitro cell experiments were performed to measure AGS cell proliferation, apoptosis, invasion and migration by MTT, Celigo cell count, flow cytometry, Transwell and wound healing assays following STAMBPL1 knockdown. The relative protein expression levels were evaluated by western blotting. When compared with the adjacent normal tissues, STAMBPL1 protein expression in the gastric cancer tissues with increasing stages was significantly upregulated (P<0.01 or P<0.001). STAMBPL1 gene expression was not identified to be significantly different between AGS and MGC80-3 gastric cancer cells (P>0.05). Following STAMBPL1 knockdown by short hairpin RNA (sh)STAMBPL1, cell proliferation was significantly suppressed, the cell apoptosis rate was significantly upregulated, and the numbers of invasive AGS cells and the AGS wound healing rate were significantly decreased (P<0.01 and P<0.001, respectively), compared with those in the shControl group. Additionally, STAMBPL1 and NF-κB protein expression levels were significantly downregulated in the shSTAMBPL1 group (P<0.001, respectively). STAMBPL1 may be oncogenic in gastric cancer, and STAMBPL1 knockdown may suppress gastric cancer development.

Incorporating molecular biomarkers into clinical practice for gastric cancer

Introduction: Gastric cancer is one of the most common causes of cancer-related mortality worldwide. To improve clinical outcomes, it is critical to develop appropriate approaches to diagnosis and treatment. Biomarkers have numerous potential clinical applications, including screening, assessing risk, determining prognosis, monitoring recurrence, and predicting response to treatment. Furthermore, biomarkers may contribute to the development of effective therapies. Areas covered: Here we review recent progress in exploiting GC-specific biomarkers such as protein-coding genes, microRNAs, long noncoding RNAs, and methylated gene promoters. Expert opinion: The development of biomarkers for diagnosing and monitoring gastric cancer and for individualizing therapeutic targets shows great promise for improving gastric cancer management.

Recent advances in molecular biomarkers for patients with hepatocellular carcinoma

Introduction: Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide and recurrence rate after curative resection remains high. To improve HCC prognosis, novel sensitive biomarkers and targeted molecular therapies are needed. Accumulation of multiple genetic aberrations caused by pathologically derived liver damage results in HCC carcinogenesis. Elucidating the genes associated with tumorigenesis and progression of HCC may lead to the development of early detection and prognosis markers and to the identification of therapeutic targets. Areas covered: We review recently reported (January 2017-March 2019) HCC-associated molecules, including protein-coding genes, microRNAs, long non-coding RNAs, and methylated gene promoters. Expert opinion: The molecules reviewed have the potential to be clinical biomarkers and therapeutic targets for HCC. The accumulation and understanding of genetic and epigenetic data are essential to improve the management of HCC patients.

LncRNA-LOC101928316 contributes to gastric cancer progression through regulating PI3K-Akt-mTOR signaling pathway

Long noncoding RNA (lncRNA) has played the important function in regulation of various biological processes and in diagnostic value has been widely appreciated. In the present study, we have found that LOC101928316 was significantly downregulated in gastric cancer (GC) tissues specimen, GC cell lines, and associated with the GC patients tumor, node, and metastasis (TNM) stage and degree of differentiation (P ＜ 0.05). LOC101928316 overexpression can significantly inhibit SGC‐7901 cell migration, invasion, and proliferation (P＜0.05). LOC101928316 molecular mechanism investigates suggested that LOC101928316 can regulate PI3K‐Akt‐mTOR signaling pathway and change the GC development progression in vivo and in vitro. In vivo experiment also revealed that LOC101928316‐Overexpression can inhibit the tumorigenicity of GC cells in tumor‐burdened experimental nude mice (P ＜ 0.05). LOC101928316 may function as anti‐oncogene and also plays an important role in GC tumorigenesis. Collectively, our data provided the key role of LOC101928316 in the tumorigenesis of GC. In addition, the present study elucidates LOC101928316 potential regulatory network, which may help us to lead a better knowing of the pathogenesis of GC and probe the lncRNA as a novel biomarker to diagnosis and therapy for this malignant tumor.

Recent advances in gastric cancer early diagnosis

Gastric cancer (GC) remains an important cause of cancer death worldwide with a high mortality rate due to the fact that the majority of GC cases are diagnosed at an advanced stage when the prognosis is poor and the treatment options are limited. Unfortunately, the existing circulating biomarkers for GC diagnosis and prognosis display low sensitivity and specificity and the GC diagnosis is based only on the invasive procedures such as upper digestive endoscopy. There is a huge need for less invasive or non-invasive tests but also highly specific biomarkers in case of GC. Body fluids such as peripheral blood, urine or saliva, stomach wash/gastric juice could be a source of specific biomarkers, providing important data for screening and diagnosis in GC. This review summarized the recently discovered circulating molecules such as microRNAs, long non-coding RNAs, circular RNAs, which hold the promise to develop new strategies for early diagnosis of GC.

Diagnostic value of apolipoprotein C-I, transthyretin and apolipoprotein C-III in gastric cancer

Diagnostic value of apolipoprotein C-I (ApoC-I), transthyretin (TTR) and ApoC-III in gastric cancer were evaluated. Retrospective analysis methods were used to collect 60 patients with gastric cancer first diagnosed in The First Affiliated Hospital of Jiaxing University. There were 60 patients with chronic atrophic gastritis in the benign lesion group and 60 healthy individuals in the control group. The expression levels of serum ApoC-I, TTR and ApoC-III was detected by enzyme-linked immunosorbent assay. Differences existed in the expression levels of ApoC-I, TTR and ApoC-III in the gastric cancer group, benign lesion group and control group (P<0.001), with the expression levels of ApoC-I, TTR and ApoC-III in the gastric cancer group being lower than that of the benign lesion group (P<0.05), and the expression levels of ApoC-I, TTR and ApoC-III in the benign lesion group being lower than that of the control group (P<0.05). The expression levels of ApoC-I, TTR and ApoC-III in the gastric cancer group were to a certain degree correlated with the clinical stage, lymph node metastasis and differentiation of patients in the gastric cancer group (P<0.05). The specificity and negative predictive value of combined detection were proven to be higher than the separate detection of the three factors (P<0.05). The detection of serum ApoC-I, TTR and ApoC-III was of great significance in the diagnosis of gastric cancer and the estimation of its severity. The method of combined detection is worth a further in-depth study as it could improve the specificity of diagnosis and have a higher negative predictive value.

Significance of SYT8 For the Detection, Prediction, and Treatment of Peritoneal Metastasis From Gastric Cancer

OBJECTIVE

To develop novel diagnostic and therapeutic targets specific for peritoneal metastasis of gastric cancer (GC).

BACKGROUND

Advanced GC frequently recurs because of undetected micrometastases even after curative resection. Peritoneal metastasis has been the most frequent recurrent pattern after gastrectomy and is incurable.

METHODS

We conducted a recurrence pattern-specific transcriptome analysis in an independent cohort of 16 patients with stage III GC who underwent curative gastrectomy and adjuvant S-1 for screening candidate molecules specific for peritoneal metastasis of GC. Next, another 340 patients were allocated to discovery and validation sets (1:2) to evaluate the diagnostic and predictive value of the candidate molecule. The results of quantitative reverse-transcription PCR and immunohistochemical analysis were correlated with clinical characteristics and survival. The effects of siRNA-mediated knockdown on phenotype and fluorouracil sensitivity of GC cells were evaluated in vitro, and the therapeutic effects of siRNAs were evaluated using a mouse xenograft model.

RESULTS

Synaptotagmin VIII (SYT8) was identified as a candidate biomarker specific to peritoneal metastasis. In the discovery set, the optimal cut-off of SYT8 expression was established as 0.005. Expression levels of SYT8 mRNA in GC tissues were elevated in the validation set comprising patients with peritoneal recurrence or metastasis. SYT8 levels above the cut-off value were significantly and specifically associated with peritoneal metastasis, and served as an independent prognostic marker for peritoneal recurrence-free survival of patients with stage II/III GC. The survival difference between patients with SYT8 levels above and below the cut-off was associated with patients who received adjuvant chemotherapy. Inhibition of SYT8 expression by GC cells correlated with decreased invasion, migration, and fluorouracil resistance. Intraperitoneal administration of SYT8-siRNA inhibited the growth of peritoneal nodules and prolonged survival of mice engrafted with GC cells.

CONCLUSIONS

SYT8 represents a promising target for the detection, prediction, and treatment of peritoneal metastasis of GC.

Increased Expression of DNAJC12 is Associated with Aggressive Phenotype of Gastric Cancer

BACKGROUND

Identification of gastric cancer-related molecules is necessary to elucidate the pathological mechanisms of this heterogeneous disease. The purpose of this study was to identify novel genes associated with aggressive phenotypes of gastric cancer.

METHODS

Global expression profiling was conducted using tissues from four patients with metastatic gastric cancer to identify genes overexpressed in gastric cancer. Fifteen gastric cell lines and 262 pairs of surgically resected gastric tissues were subjected to mRNA expression analysis. The contribution of the candidate gene on gastric cancer cell proliferation, invasion, adhesion, and migration were evaluated using small interfering RNA.

RESULTS

DnaJ heat shock protein family (Hsp40) member C12 (DNAJC12) was identified as a candidate gene by transcriptome analysis. In clinical samples, DNAJC12 mRNA levels were higher in gastric cancer tissues compared with normal adjacent tissues. Patients with high DNAJC12 expression showed significantly shorter overall survival in our cohort and in the extra-validation cohort analyzed by a published microarray dataset. High DNAJC12 expression in gastric cancer tissues was significantly associated with lymphatic involvement, infiltrative growth type, lymph node metastasis, and advanced stage and was identified as an independent prognostic factor for overall survival in multivariable analysis. Increased expression of DNAJC12 was found in 12 of 14 examined gastric cancer cell lines. Knockdown of DNAJC12 expression significantly decreased the proliferation and invasion abilities of gastric cancer cells.

CONCLUSIONS

Our findings support DNAJC12 as a candidate gene associated with aggressive phenotypes of gastric cancer.

Significant association between KDM1A promoter hypomethylation and colorectal cancer in Han Chinese

Lysine-specific histone demethylase 1A gene (KDM1A) promotes tumorigenesis. The aim of this study was to investigate the association between KDM1A methylation and colorectal cancer (CRC). Currently, we collected 37 paired CRC tissues and adjacent non-tumor tissues from Jiangsu province and 75 paired CRC tissues and adjacent non-tumor tissues from Zhejiang province to conduct a two-stage experiment to study the association between KDM1A methylation and CRC. We used qMSP to measure the KDM1A promoter methylation, and the percentage of methylation reference (PMR) to quantify the KDM1A promoter methylation level. To investigate the effect of the selected KDM1A fragment on gene expression regulation, we also performed a dual luciferase reporter gene assay. In the stage I study, the KDM1A promoter methylation level in CRC tumor tissues was significantly lower than that in adjacent non-tumor tissues (median PMR: 6.93% vs 10.25%, P =  0.033). The results of the stage II study were similar to those of the stage I study (mean PMR: 12.94% versus 17.42%, P =  0.016). In addition, a clinical pathology subgroup analysis found that KDM1A hypomethylation was associated with CRC only in patients with well-differentiated CRC (stage I: P =  0.047; stage II: P =  0.040). The dual luciferase reporter assay showed that the transcriptional activity of the recombinant pGL3-KDM1A plasmid was significantly higher (fold change = 2, P =  0.0009). In conclusion, our results suggest that KDM1A hypomethylation is significantly associated with CRC.

Gastric Cancer Cell Lines Have Different MYC-Regulated Expression Patterns but Share a Common Core of Altered Genes

MYC is an oncogene responsible for excessive cell growth in cancer, enabling transcriptional activation of genes involved in cell cycle regulation, metabolism, and apoptosis, and is usually overexpressed in gastric cancer (GC). By using siRNA and Next-Generation Sequencing (NGS), we identified MYC-regulated differentially expressed Genes (DEGs) in three Brazilian gastric cancer cell lines representing the histological subtypes of GC (diffuse, intestinal, and metastasis). The DEGs were picked using Sailfish software, followed by Gene Set Enrichment Analysis (GSEA) and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway analysis using KEGG. We found 11 significantly enriched gene sets by using enrichment score (ES), False Discovery Rate (FDR), and nominal P-values. We identified a total of 5.471 DEGs with correlation over (80%). In diffuse-type and in metastatic GC cell lines, MYC-silencing caused DEGs downregulation, while the intestinal-type GC cells presented overall DEGs upregulation after MYC siRNA depletion. We were able to detect 11 significant gene sets when comparing our samples to the hallmark collection of gene expression, enriched mostly for the following hallmarks: proliferation, pathway, signaling, metabolic, and DNA damage response. When we analyzed our DEGs considering KEGG metabolic pathways, we found 12 common branches covering a wide range of biological functions, and three of them were common to all three cell lines: ubiquitin-mediated proteolysis, ribosomes, and system and epithelial cell signaling in Helicobacter pylori infection. The GC cell lines used in this study share 14 MYC-regulated genes, but their gene expression profile is different for each histological subtype of GC. Our results present a computational analysis of MYC-related signatures in GC, and we present evidence that GC cell lines representing distinct histological subtypes of this disease have different MYC-regulated expression profiles but share a common core of altered genes. This is an important step towards the understanding of MYC's role in gastric carcinogenesis and an indication of probable new drug targets in stomach cancer.

miR-29b negatively regulates MMP2 to impact gastric cancer development by suppress gastric cancer cell migration and tumor growth

MicroRNAs (miRNAs) are important regulators and associated with the development of many different types of cancer, including gastric cancer. However, their pathophysiologic role and their relevance to tumorigenesis, invasion and metastasis are still unknown. In our current study, we performed microRNA array and found that 28 of miRNAs were differentially expressed in INF type of gastric cancer. Among 28 miRNAs, miR-29b was one of the most significantly down-regulated miRNA. Further bioinformatics analysis showed that MMP2 was a potential target of miR-29b. Interestingly, luciferase analysis showed that miR-29b negatively regulates MMP2 by binding with the miRNA response element (MRE) on the 3'UTR of MMP2. In addition, overexpression of miR-29b significantly decreased the mRNA and protein level of MMP2 and the activity of MMP2 to suppress gastric cancer cell migration. Moreover, lentivirus mediated overexpression of miR-29b dramatically suppressed the ability of BGC823 cells to form colonies in vitro and their ability to develop tumor in vivo in nude mice. Finally, our qPCR and western blot analysis showed that miR-29b was significantly reduced in clinical gastric cancer tissue, whereas MMP2 protein was significantly up-regulated, suggesting that this aberrant down-regulation of miR-29b might be associated with the abnormal regulation of MMP2 and the development of gastric cancer. Significant apparent was also found between miR-29b expression and TNM staging, lymph node status, tumor differentiation and Ming classification. Together, our data suggest an important regulatory role of miR-29b in the development of gastric cancer. Thus, miR-29b and MMP2 might be important diagnostic or therapeutic targets for human tumor diseases.