Prevention strategies for gastric cancer: a global perspective

Burden of Stomach Cancer Incidence, Mortality, Disability-Adjusted Life Years, and Risk Factors in 204 Countries, 1990-2019: An Examination of Global Burden of Disease 2019

BACKGROUND

Stomach cancer is a global health problem and is one of the leading causes of cancer deaths worldwide. This study investigates the spatial and temporal patterns of stomach cancer burden in 204 countries in the last three decades.

DATA AND METHODS

The estimates of stomach cancer burden and its risk factors were obtained from the Global Burden of Disease (GBD) 2019 study, covering the years 1990 to 2019, across 204 countries within 21 world regions. GBD employs the cause-of-death ensemble modeling framework to calculate disease-specific mortality estimates. Estimated average percent change (EAPC) of absolute counts (incidence, mortality, and disability-adjusted life years (DALYs)) and age-standardized rates (age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR), and age-standardized DALYs rate (ASDALR)) was calculated in the regions to illustrate the relative changes between 1990 and 2019. Joinpoint regression was used to analyze global trends of stomach cancer burden in the last three decades.

RESULTS

Incidence of stomach cancer globally increased from 883,396 cases in 1990 to 1.3 million cases in 2019 and number of deaths due to stomach cancer rose from 788,317 in 1990 to 957,185 in 2019. Between 1990 and 2019, the global ASIR decreased from 22.4 per 100,000 to 15.6 per 100,000, the ASMR decreased from 20.5 per 100,000 to 11.9 per 100,000 and the ASDALR declined from 493.4 per 100,000 to 290.6 per 100,000. Trend analysis using joinpoint regression revealed the slowest rise in incident cases and largest decline in ASIR between 2004 and 2016. In 2019, East Asia had the highest number of incident cases, totaling 626,489, followed by high-income Asia-Pacific (128,168) and South Asia (99,399). The ASIR was the highest in East Asia (30.2/100,000) followed by high-income Asia-Pacific (28.2/100,000) and Andean Latin America (22.4/100,000), while high-income North America had the lowest ASIR at 6.1/100,000. In terms of absolute counts, the top three countries in 2019 were China, India, and Japan together accounting for 61.5% of global incident cases, 58.6% of deaths, and DALYs. Mongolia had the highest ASIR (43.7 per 100,000), followed by Bolivia (34.0 per 100,000) and China (30.6 per 100,000) in 2019, while the lowest ASIR was 3.3 per 100,000 in Malawi. Globally, for both sexes combined, 7.8% of stomach cancer DALYs were associated with a diet high in sodium and 17.2% were linked to smoking. Among males, 24.0% of stomach cancer DALYs were attributable to smoking, compared to only 4.3% in females in 2019.

CONCLUSION

Significant progress has been made globally in the fight against stomach cancer, with the ASIR decreasing by 30.3% and the ASMR by 41.2% between 1990 and 2019. To further reduce the burden of stomach cancer, it is essential to address factors such as Helicobacter pylori prevalence, obesity, and smoking. Additionally, improvements in early detection, socioeconomic development (including better public sanitation, hygiene, and drinking water), and dietary habits are imperative.

Circulating long noncoding RNA, Zfpm2-As1, and XIST based on medical data analysis are potential plasma biomarkers for gastric cancer diagnosis

BACKGROUND

Long noncoding RNAs (lncRNAs) participate in diseases, especially tumorigenesis, including gastric cancer (GC). Although lncRNAs in GC tissues have been extensively studied in previous research, the possible significance of circulating lncRNAs in diagnosing GC is still unknown.

OBJECTIVE

The present work investigated lncRNAs ZFPM2-AS1 and XIST with high expression in GC tissues proved as potential plasma biomarkers from 20 early GC cases, 100 GC cases, and 90 normal subjects.

METHODS

The possible correlation between ZFPM2-AS1 and XIST expression levels was analyzed with general characteristics and clinicopathological features. The performance in diagnosis was assessed according to receiver operating characteristic (ROC) analysis.

RESULTS

According to the results, XIST and ZFPM2-AS1 expression remarkably increased within GC plasma relative to normal subjects (P< 0.01); besides, lncRNA XIST expression after surgery had a tendency of downregulation compared with preoperative levels (P< 0.05). Moreover, the area under ROC curve (AUC) values were 0.62 for ZFPM2-AS1 and 0.68 for XIST, while the pooled AUC value of CA-724 and two lncRNAs was 0.751.

CONCLUSION

Circulating lncRNAs ZFPM2-AS1 and XIST can serve as the candidate plasma biomarkers used to diagnose GC.

Gastric Cancer: A Comprehensive Literature Review

Gastric cancer stands as a significant global health concern, particularly prevalent in Eastern Asia, with high mortality rates urging urgent attention and research efforts. This article comprehensively explores the epidemiology, anatomy, risk factors, pathophysiology, clinical presentation, diagnosis, staging, treatment modalities, prevention strategies, and survival rates associated with gastric cancer. Notably, Helicobacter pylori infection, dietary choices, and intricate stomach anatomy play pivotal roles in disease development. Early detection, utilizing staging, grading, and genetic testing for personalized treatment approaches is emphasized. Treatment modalities encompass surgery, chemotherapy, radiation therapy, targeted therapy, and immunotherapy. Prevention strategies involve lifestyle changes, screening, and genetic counseling. Survival rates vary by stage, highlighting the need for individualized care. In conclusion, a collaborative global effort is essential to address the impact of gastric cancer and improve outcomes.

M-CSF secreted by gastric cancer cells exacerbates the progression of gastric cancer by increasing the expression of SHP2 in tumor-associated macrophages

OBJECTIVE

To investigate the effect of Src homology 2 domain-containing tyrosine phosphatase-2 (SHP2) in tumor-associated macrophages (TAMs), which is mediated by macrophage colony-stimulating factor (M-CSF) secreted by gastric cancer cells, on the development of gastric cancer and its molecular mechanism.

METHODS

The progression of gastric cancer was detected by nude mouse tumor-bearing experiments. Colony formation assay and cell counting kit-8 (CCK8) assay were used to detect the proliferation capacity of gastric cancer cells. The migration capacity of gastric cancer cells was examined by wound healing assay. Transwell migration and invasion assays were performed on gastric cancer cells. Detection of relevant protein expression using western blotting.

RESULTS

Overexpression of SHP2 could promote the progression of gastric cancer in nude mice. The results of colony formation assay and CCK8 assay showed that overexpression of SHP2 could enhance the proliferation of gastric cancer cells. It was found by wound healing assay and Transwell assay that overexpression of SHP2 could facilitate the migration and invasion of gastric cancer cells. The results of Western blotting revealed that overexpression of SHP2 could increase the expressions of p-STAT3, s-PD-1, p-Src, p-Lyn, p-PI3K, p-AKT, Arginase-1, MMP1 and MMP3 but decrease the expressions of TBK1 and SOCS1 in TAMs, and also increase the expressions of CD9, TSG101 and s-PD-1 in exosomes.

CONCLUSION

M-CSF secreted by gastric cancer cells can promote the proliferation, invasion and migration of gastric cancer cells by increasing the expression of SHP2 in TAMs.

HOXC8 mediates osteopontin expression in gastric cancer cells

Genes of the homeobox (HOX) family encode transcription factors, which play a role in cancer progression. However, their role in gastric cancer has not been adequately evaluated. Herein, we evaluated the genetic changes and mRNA of target genes of the HOX family in gastric cancer patients using publicly available online datasets. We found that HOXC8 was amplified in gastric cancer tissues, and mRNA expression levels were significantly associated with tumor status (P=0.044) and poor overall survival (P<0.01). HOXC8 knockdown significantly reduced the viability of gastric cancer cell lines. HOXC8 modulated the expression of secreted phosphoprotein 1 (SPP1, osteopontin) and phosphorylation of AKT/ERK in gastric cancer cells. Survival analysis demonstrated a decrease in overall survival rates among the high HOXC8/high SPP1 expression group compared with the low HOXC8/low SPP1 expression group. In conclusion, HOXC8 may be an independent prognostic factor and serve as a useful predictive biomarker for gastric cancer.

Incidence and Patterns of Digestive Organ Cancer in Georgia: Insights from a Population-Based Registry Study in 2021

Digestive organ cancer, also known as gastrointestinal (GI) cancer, refers to cancer that occurs in the digestive tract. In this population-based registry study, we aimed to investigate the incidence of GI in Georgia and to identify any patterns in the occurrence of different types of this disease. The study included all cases of GI cancer that were diagnosed in Georgia in 2021. We analyzed 1635 patients' data to determine the overall and age-standardized incidence of GI cancer in the country. The analyses were performed for esophagus, stomach, colon, rectum, anus, liver and intrahepatic bile ducts, gallbladder, and pancreas separately. The descriptive statistics used in the study-specifically counts, means, proportions, and rates-were calculated using the statistical software STATA version 17.0. (StataCorp, College Station, TX, USA). The results of the study showed that the incidence of digestive organ cancer in Georgia was similar to the global average. However, there were some notable differences in the specific types of GI cancer that were most common in the country. Overall, this study provides important insights into the incidence of digestive organ cancer in Georgia and highlights the need for further research to better understand the factors that contribute to this disease.

Dual-Regulated Mechanism of EZH2 and KDM6A on SALL4 Modulates Tumor Progression via Wnt/β-Catenin Pathway in Gastric Cancer

BACKGROUND

SALL4 has been demonstrated in many cancers and participated in tumorigenesis and tumor progression, however, its expression and function still remain ambiguous in GC, especially its upstream mechanistic modulators.

PURPOSE

We explored whether the dual mediation of EZH2 and KDM6A could be involved in upstream regulation of SALL4, which promotes GC cell progression via the Wnt/β-catenin pathway.

METHOD

Analysis of discrepant gene expression in GC and normal gastric tissues from The Cancer Genome Atlas (TCGA) dataset. GC cell lines were transfected by siEZH2 and siKDM6A, the transduction molecules of KDM6A/EZH2-SALL4-β-catenin signaling were quantified in the GC cells.

RESULTS

Here, we showed that only SALL4 levels of SALL family members were upregulated in nonpaired and paired GC tissues than those in corresponding normal tissues and were associated with its histological types, pathological stages, TNM stages including T stage (local invasion), N stage (lymph node metastasis), M stage (distant metastasis), and overall survival from the TCGA dataset. SALL4 level was elevated in GC cells compared to normal gastric epithelial cell line (GES-1) and was correlated to cancer cell progression and invasion through the Wnt/β-catenin pathway in GC, which levels would be separately upregulated or downregulated by KDM6A or EZH2.

CONCLUSION

We first proposed and demonstrated that SALL4 promoted GC cell progression via the Wnt/β-catenin pathway, which was mediated by the dual regulation of EZH2 and KDM6A on SALL4. This mechanistic pathway in gastric cancer represents a novel targetable pathway.

Microbiota Effect on Trimethylamine N-Oxide Production: From Cancer to Fitness-A Practical Preventing Recommendation and Therapies

Trimethylamine N-oxide (TMAO) is a microbial metabolite derived from nutrients, such as choline, L-carnitine, ergothioneine and betaine. Recently, it has come under the spotlight for its close interactions with gut microbiota and implications for gastrointestinal cancers, cardiovascular disease, and systemic inflammation. The culprits in the origin of these pathologies may be food sources, in particular, high fat meat, offal, egg yolk, whole dairy products, and fatty fish, but intercalated between these food sources and the production of pro-inflammatory TMAO, the composition of gut microbiota plays an important role in modulating this process. The aim of this review is to explain how the gut microbiota interacts with the conversion of specific compounds into TMA and its oxidation to TMAO. We will first cover the correlation between TMAO and various pathologies such as dysbiosis, then focus on cardiovascular disease, with a particular emphasis on pro-atherogenic factors, and then on systemic inflammation and gastrointestinal cancers. Finally, we will discuss primary prevention and therapies that are or may become possible. Possible treatments include modulation of the gut microbiota species with diets, physical activity and supplements, and administration of drugs, such as metformin and aspirin.

PHF5A facilitates the development and progression of gastric cancer through SKP2-mediated stabilization of FOS

BACKGROUND

Gastric cancer (GC) is the fifth most common cancer and the third most common cause of cancer death worldwide. Plant homeodomain (PHD)-finger domain protein PHF5A has been demonstrated to play a promoting role in a variety of cancers. This study aimed to clarify the role of PHF5A in the progression of GC and its potential mechanism of action.

METHODS

Immunohistochemical staining experiments were performed based on tissues from clinical GC patients to reveal PHF5A expression. A series of functional experiments in vitro and in vivo were used to clarify the role of PHF5A in GC.

RESULTS

Clinically, PHF5A was abundantly expressed in GC and existed clinical value indicating poor prognosis. In addition, GC cells with knockdown of PHF5A expression showed slowed proliferation, enhanced sensitivity to apoptosis and inhibition of migration. Mechanically, knockdown of PHF5A led to decreased protein stability of FOS, which was mediated ubiquitination of E3 ubiquitin ligase S-phase kinase-associated protein 2 (SKP2). Moreover, downregulation of FOS attenuated the promotion of PHF5A overexpression on GC cells. Consistently, Pladienolide B (PHF5A inhibitor) treatment reversed the induction of PHF5A overexpression on the malignant phenotypes and tumor formation of GC cells.

CONCLUSION

Knockdown of PHF5A inhibited the progression of GC through SKP2-mediated ubiquitination of FOS, which may be a promising candidate target with potential therapeutic value.

Global burden of major gastrointestinal cancers and its association with socioeconomics, 1990-2019

BACKGROUND

To understand the impact of common cancers of the gastrointestinal tract and help to formulate evidence-based policy, we evaluate the relationship between the burden of GI tract cancers and socioeconomics.

METHODS

Data on GI tract cancer burden were obtained from the Global Burden of Disease (GBD) 2019 including mortality and incidence rates. According to the Socio-demographic Index (SDI) level, country and territory, and sex, etc., the data were further stratified. The association between the burden of GI tract cancer and socioeconomics, indicated by SDI, was described. Uncertainty analysis was estimated using bootstrap draw.

RESULTS

In 2019, five major cancers of the gastrointestinal tract led to an age-standardized incidence rate (ASIR) of 61.9 (95% CI 56.1-67.6) per 100 000 person-years. From 1990 to 2019, five common tumors of the gastrointestinal tract related age-standardized death rates (ASDRs) decreased by -22.7% (-31.1 to -13.5). For the five common tumors, ASIRs and ASDRs were both higher in males than those in females. Globally, Mongolia, and several East Asia countries exhibited the highest ASIRs in 2019. The high SDI, and high-middle SDI locations recorded the highest incidence rate and death rate of colon and rectum cancer and pancreatic cancer. On the contrary, the low-middle SDI, and low SDI locations possessed the highest incidence rate and death rate of stomach cancer and esophageal cancer.

CONCLUSION

There is a profound association between socioeconomics and burden of common cancers of the gastrointestinal tract. It would be helpful for the high SDI, and high-middle SDI locations to pay special attention to the screening of colon and rectum cancer and pancreatic cancer while the low-middle SDI, and low SDI locations should pay more attention to the screening of stomach cancer and esophageal cancer.

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.

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

Background

Gastric 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.

Methods

The 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.

Results

Differential 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.

Conclusions

The 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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-022-00491-8.

Prevalence of Helicobacter pylori in Non-Cardia Gastric Cancer in China: A Systematic Review and Meta-Analysis

Non-cardia gastric cancer was significantly associated with Helicobacter pylori (H. pylori) infection. Reducing H. pylori prevalence was an important prevention strategy for non-cardia gastric cancer. However, national-level data on the H. pylori prevalence in non-cardia gastric cancer were limited in China. Therefore, we conducted this study to estimate the pooled prevalence of H. pylori in non-cardia gastric cancer in China. We searched PubMed, Embase, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wan Fang, and VIP Database for Chinese Technical Periodicals for studies reporting H. pylori prevalence in non-cardia gastric cancer in China which were published before September 1, 2021. Pooled prevalence was calculated using a random-effect model. Subgroup analysis and meta-regression were used to explore the potential sources of heterogeneity. Egger’s test and funnel plot were used to assess publication bias. A total number of 55 studies with 5324 cases of non-cardia gastric cancer were included in this study. The pooled prevalence of H. pylori in non-cardia gastric cancer in China was 66.5% (95%CI: 62%-71%, I²=93.8%, P<0.0001). In subgroup analysis, a significant difference in the prevalence of H. pylori in non-cardia gastric cancer was noted when stratified by geographic region of China (P=0.0112). The highest H. pylori prevalence (78.9%, 95%CI: 69.9%-87.8%) was noted in Northwest China and the lowest (53.1%, 95%CI: 38.9%-67.3%) was in North China. In meta-regression, a significant association between H. pylori prevalence and geographic region was found, while type of sample, H. pylori testing method, diagnosis period, detection timing, type of study design, quality grade, publication year, and sample size were not associated with the prevalence of H. pylori in non-cardia gastric cancer (P>0.05). A large proportion of non-cardia gastric cancers were associated with H. pylori infection in China, emphasizing the possible benefits of H. pylori eradication for the prevention and control of non-cardia gastric cancer.

The Effect of Palliative Invasive Interventions on Overall Survival in the Last 3 Months of Life in Metastatic Gastric Cancer

PURPOSE

Gastric cancer is one of the biologically aggressive and highly mortal cancers. In addition to limited treatment options, especially in advanced stages, palliative treatment methods are applied to increase patients' quality of life with gastric cancer. This study aims to discuss the effects of paracentesis, thoracentesis, tube thoracostomy, double J catheter nephrostomy, percutaneous transhepatic cholangiography (PTC), and abscess drainage catheter placement procedures applied in the last 3 months for problems requiring palliation, in the light of literature.

METHOD

The patient characteristics of the patients and, in addition, the history of any invasive intervention for palliative treatment in the last 3 months were questioned and recorded with the electronic medical record system. The effect of an invasive intervention on survival was examined. The data of patients with metastatic gastric cancer followed in the medical oncology clinic between February 2012 and May 2020 were reviewed retrospectively.

CONCLUSIONS

In this study, in which the effect of palliative invasive intervention (PIG) stories on survival in the last 3 months of life of patients diagnosed with metastatic gastric cancer was examined, no significant difference was found between those who underwent PIG and those who did not, in terms of overall survival. However, since PIG was not included in the design of our study, the effect of PIG in terms of quality of life, mood, motivation of patient relatives, and the cost is unknown.

RESULTS

In the final analysis, it was noted that 143 (94.1%) of the 152 patients included in the study died and 9 (5.9%) were still alive. Overall survival of all patients was reported as 12.9 months (95% CI, 10.9-14.9). The mean overall survival of 36 patients who underwent palliative invasive intervention (PIG) in the last 3 months was 13.0 months (95% CI, 9.1-17.0), and a similar 13.0 months (95% CI, 10.6-15.3) of 116 patients who did not undergo PIG no significant difference was found (p: 0.887).

Prediction models for gastric cancer risk in the general population: a systematic review

Risk prediction models for gastric cancer (GC) could identify high-risk individuals in the general population. The objective of this study was to systematically review the available evidence about the construction and verification of GC predictive models. We searched PubMed, Embase, and Cochrane Library databases for articles that developed or validated GC risk prediction models up to November 2021. Data extracted included study characteristics, predictor selection, missing data, and evaluation metrics. Risk of bias (ROB) was assessed using the Prediction model study Risk Of Bias Assessment Tool (PROBAST). We identified a total of 12 original risk prediction models that fulfilled the criteria for analysis. The area under the receiver operating characteristic curve ranged from 0.73 to 0.93 in derivation sets (n=6), 0.68 to 0.90 in internal validation sets (n=5), 0.71 to 0.92 in external validation sets (n=7). The higher-performing models usually include age, salt preference, Helicobacter pylori, smoking, BMI, family history, pepsinogen and sex. According to PROBAST, at least one domain with a high ROB was present in all studies mainly due to methodologic limitations in the analysis domain. In conclusion, although some risk prediction models including similar predictors have displayed sufficient discriminative abilities, many have a high ROB due to methodological limitations and are not externally validated efficiently. Future prediction models should adherence to well-established standards and guidelines to benefit GC screening.

Sijunzi Decoction Inhibits Stemness by Suppressing β-Catenin Transcriptional Activity in Gastric Cancer Cells

OBJECTIVE

To investigate a previously uncharacterized function of Sijunzi Decoction (SJZD) in inhibition of gastric cancer stem cells (GCSCs).

METHODS

MKN74 and MKN45, two CD44 positive gastric cancer cell lines with stem cell properties were used. The cells were divided into 2 groups. Treatment group was treated with SJZD (1-5 mg/mL) for indicated time (48 h-14 days). The control group was treated with equal volume of phosphate buffered saline. Cell Counting Assay Kit-8 were used to measure cell viability. Spheroid colony formation and GCSCs marker expression were performed to determine GCSCs stemness. Cell fractionation and chromatin immunoprecipitation assays were used to assess the distribution and DNA-binding activity of β-catenin after SJZD treatment, respectively.

RESULTS

SJZD treatment repressed cell growth and induced apoptosis in MKN74 and MKN45 cell lines (P<0.05). Moreover, SJZD dramatically inhibited formation of spheroid colony and expression of GCSC markers in GC cells (P<0.05). Mechanistically, SJZD reduced nuclear accumulation and DNA binding activity of β-catenin (P<0.05), the key regulator for maintaining CSC stemness.

CONCLUSION

SJZD inhibits GCSCs by attenuating the transcriptional activity of β-catenin.

Identification and epidemiological evaluation of gastric cancer risk factors: based on a field synopsis and meta-analysis in Chinese population

To summarize and assess the credibility and strength of non-genetic factors and genetic variation on gastric cancer risk, we performed a field synopsis and meta-analysis to identify the risk of gastric cancer in Chinese population. Cumulative evidence was graded according to the Venice criteria, and attributable risk percentage (ARP) and population attributable risk percentage (PARP) were used to evaluate the epidemiological effect. A total of 956 studies included non-genetic (404 studies) and genetic factors (552 studies) were quantified, and data on 1161 single nucleotide polymorphisms (SNPs) were available. We identified 14 non-genetic factors were significantly associated with gastric cancer risk. For the analysis of time trends, H. pylori infection rate in gastric cancer and population showed a downward trend. Meanwhile 22 variants were identified significantly associated with gastric cancer: 3 (PLCE1 rs2274223, PSCA rs2976392, MUC1 rs4072037) were high and 19 SNPs were intermediate level of summary evidence, respectively. For non-genetic factors, the top three for ARP were 54.75% (pickled food), 65.87% (stomach disease), and 49.75% (smoked and frying). For PARP were 34.22% (pickled food), 34.24% (edible hot food) and 23.66%(H. pylori infection). On the basis of ARP and PARP associated with SNPs of gastric cancer, the top three for ARP were 53.91% (NAT2, rs1799929),53.05% (NAT2 phenotype), and 42.85% (IL-10, rs1800896). For PARP (Chinese Han in Beijing) were 36.96% (VDR, rs731236), 25.58% (TGFBR2, rs3773651) and 20.56% (MUC1, rs4072037). Our study identified non-genetic risk factors and high-quality biomarkers of gastric cancer susceptibility and their contribution to gastric cancer.

Knockdown of PYCR1 suppressed the malignant phenotype of human hepatocellular carcinoma cells via inhibiting the AKT pathway activation

Hepatocellular carcinoma (HCC) is a common and highly malignancy tumor. Pyrroline-5-carpoxylate reductase-1 (PYCR1) is an active enzyme involved in cell metabolism. In this study, we explored the role of PYCR1 in the HCC cell lines, Hep3B and HepG2. The expression of PYCR1 was up-regulated in liver hepatocellular carcinoma (LIHC) tissue by GEPIA. Meanwhile the overall survival rate (OS) showed that patients with high PYCR1 expression had a worse prognosis compared with patients with low PYCR1 level. In addition, knockdown of PYCR1 suppressed the proliferation, invasion and migration of Hep3B and HepG2 cells and promoted the apoptosis and G1 arrest. Knockdown of PYCR1 reduced the expression of the anti-apoptotic protein Bcl-2 and increased the expression of pro-apoptotic protein Bax and Caspase3. Furthermore, knockdown of PYCR1 changed the expression of p-AKT and its target gene Cyclin D1. In conclusion, knockdown of PYCR1 inhibited the malignant phenotype of human HCC cells by regulating the AKT pathway activation, which provides a potential strategy for the human HCC therapy.

Association of Helicobacter pylori Infection and Host Cytokine Gene Polymorphism with Gastric Cancer

The global cancer burden of new cases of various types rose with millions of death in 2018. Based on the data extracted by GLOBOCAN 2018, gastric cancer (GC) is the third leading cause of mortality related to cancer across the globe. Carcinogenic or oncogenic infections associated with Helicobacter pylori (Hp) are regarded as one of the essential risk factors for GC development. It contributes to the increased production of cytokines that cause inflammation prior to their growth in the host cells. Hp infections and specific types of polymorphisms within the host cells encoding cytokines are significant contributors to the host's increased susceptibility in terms of the development of GC. Against the backdrop of such an observation is that only a small portion of the cells infected can become malignant. The diversities are a consequence of the differences in the pathogenic pathway of the Hp, susceptibility of the host, environmental conditions, and interplay between these factors. It is evident that hosts carrying cytokine genes with high inflammatory levels and polymorphism tend to exhibit an increased risk of development of GC, with special emphasis being placed on the host cytokines gene polymorphisms.

Circulating exosomal long non-coding RNA H19 as a potential novel diagnostic and prognostic biomarker for gastric cancer

Objective

Long non-coding RNAs (lncRNAs) are involved in carcinogenesis and could be used as diagnostic biomarkers. Our study aimed to elucidate the clinical role of serum exosomal lncRNA H19 in gastric cancer (GC).

Methods

In this prospective clinical study, we determined serum exosomal lncRNA H19 levels in 81 patients with GC and analysed the correlations between serum lncRNA H19 levels and clinical characteristics. Receiver operating characteristics (ROC) curves were constructed to determine the diagnostic performance of exosomal lncRNA H19 in GC.

Results

Serum exosomal lncRNA H19 levels were significantly upregulated in patients with GC both before and after surgery compared with healthy controls. Furthermore, serum exosomal lncRNA H19 levels were significantly decreased after compared with before surgery in patients with GC. Preoperative lncRNA H19 levels were significantly correlated with TNM stage. The area under the ROC curve (AUC) value for exosomal lncRNA H19 was 0.849, which was significantly higher than the AUC values for cancer antigens 19-9 and 72-4 and carcinoembryonic antigen, either alone or combined.

Conclusions

These results suggest that circulating exosomal lncRNA H19 may be a potential biomarker with diagnostic and prognostic value in GC.

Identification of an antitumor effect of demethylzeylasteral on human gastric cancer cells

Gastric cancer is a common malignancy in China, with the second highest mortality rate worldwide. Advanced gastric cancer usually exhibits a poor prognosis with a low 5-year survival rate. Therefore, developing novel drugs for the treatment of this cancer will be beneficial for patients. Demethylzeylasteral, an extract of tripterygium wilfordii, has shown positive anticancer activities. However, the possible antitumor effect of demethylzeylasteral on gastric cancer cells and its underlying molecular mechanism remain to be determined. In the present study, the Cell Counting Kit-8 and colony formation assays revealed that demethylzeylasteral impeded the proliferation of human gastric cancer cells in a dose-dependent manner. Furthermore, the Transwell assay identified an inhibitory effect of demethylzeylasteral on the migration of MKN-45 cells, while flow cytometry found that treatment with demethylzeylasteral induced apoptosis and decreased the mitochondrial membrane potential in the cancer cells. Further investigation revealed that demethylzeylasteral downregulated the phosphorylation of ERK1/2, AKT, and GSK-3β in MKN-45 cells. Notably, decreased expression of Bcl-2 and increased expression of Bax, cleaved caspase-3, cleaved caspase-9 and cleaved PARP were detected in the cancer cells treated with demethylzeylasteral. The present study demonstrated that demethylzeylasteral exhibits therapeutic potential for gastric cancer.

Silencing lncRNA XIST exhibits antiproliferative and proapoptotic effects on gastric cancer cells by up-regulating microRNA-132 and down-regulating PXN

The present study aims to elucidate the potential therapeutic role of lncRNA XIST in gastric cancer through regulation of microRNA-132 (miR-132) and paxillin (PXN) expression. The study employed 65 gastric cancer tissue specimens and SGC7901 cell lines. Our results demonstrated that expression of lncRNA XIST and PXN was significantly elevated while the expression of miR-132 was significantly reduced in gastric cancer tissues. Dual-luciferase, RNA pull-down and RIP assays demonstrated that lncRNA XIST up-regulated the PXN expression by competitively binding to miR-132. Moreover, silencing of lncRNA XIST and up-regulation of miR-132 could suppress tumor formation ability, cell proliferation and migration, but enhanced apoptosis in gastric cancer. However, the overexpression of PXN achieved the opposite tumor-promotive effect. Meanwhile, rescue experiments suggested that silencing of lncRNA XIST could reverse the tumor-promotive effect exerted by either miR-132 inhibitor or PXN. Taken together, the present study demonstrates lncRNA XIST as a novel oncogenic lncRNA in gastric cancer, highlighting its therapeutic role in this disease.

Evaluation of the Methylation of MIR129-2 Gene in Gastric Cancer

BACKGROUND

Genetic and epigenetic changes have strong role in the development of gastric cancer. The mutation of the MIR129-2 gene is one of the major causes in many cancers, especially gastric cancer. The aim of this study was to investigate the methylation changes of the MIR129-2 gene in tumor and normal tissue of patients with gastric cancer.

METHOD

In this study, 50 gastric cancer patients with Iranian Azari ethnic origin without any familial relations were included. Genomic DNAs was extracted from the tumoral and normal tissues. Then the promotor regions of the MIR129-2 gene were analyzed by methylation-specific PCR (MSP) to evaluate the presence or absence of methylated CpG sites.

RESULTS

There was a statistically significant difference in methylation level of MIR129-2 gene between tumoral and normal tissues. It was observed that 84 out of 100 CpG cites were methylated in tumoral tissues in compression to 13 out of 100 CpG cites in normal tissues.

CONCLUSION

MIR129-2 gene was hypermethylated in tumoral tissues, suggesting that methylation is involved in the development of gastric cancer.

Comparison of prognostic factors in different age groups and prognostic significance of neutrophil-lymphocyte ratio in patients with gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most common malignant tumors in the world. Although in recent years tremendous progress has been made in its early detection, the postoperative overall survival (OS) of GC patients remains extremely low. A number of studies have shown that age, to varying degrees, affects the prognosis of patients with GC. Therefore, this study retrospectively analyzed the clinical and pathologic data of patients with GC to explore the differences in the clinical characteristics and prognostic factors in different age groups.

AIM

To explore the difference in clinicopathological characteristics and prognostic factors in GC patients in different age groups.

METHODS

In this retrospective study, we analyzed 1037 GC patients admitted to Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from May 2010 to January 2013. The patients were divided into two groups based on age: Younger group (less than 70 years old) and older group (no less than 70 years old). In the younger group, we subdivided the patients in two subgroups by a cut-off value of 45 years. The clinical features and prognostic factors were analyzed in both groups. Subsequently, we retrieved studies that evaluated the predictive role of neutrophil-lymphocyte ratio (NLR) by searching two medical databases, PubMed and EMBASE, to conduct a meta-analysis. Random-effects model was used to pool the data.

RESULTS

In the retrospective study, the mean OS time of the younger group (64.7 mo) was significantly longer than that of the older group (48.1 mo) (P < 0.001). Among patients under 70 years of age, hospitalization time, tumor–node–metastasis (TNM) stage, vascular invasion, and preoperative low pre-albumin were independently associated with OS (P < 0.005). In patients aged 70 years and above, TNM stage, esophageal invasion, histological type, and preoperative NLR were independent factors for OS (P < 0.05). The OS of these older patients was also significantly shorter (P < 0.05). In the meta-analysis, 19 retrieved studies included a total of 8312 patients, among whom 3558 had elevated NLR values. The results showed that high NLR value was a risk factor for the prognosis of GC (P < 0.01).

CONCLUSION

The OS of elderly patients is significantly worse than that of younger patients. There are significant differences in clinicopathological characteristics and prognostic factors between younger and older patients. NLR is a convenient, inexpensive, and reproducible marker that can be used as an important predictor of the prognosis of GC.

Immune suppressed tumor microenvironment by exosomes derived from gastric cancer cells via modulating immune functions

Gastric cancer is one of the leading causes of cancer-related death due to late diagnosis with high metastatic frequency. In this study, the impact of tumor secreted exosomes on immune function in the tumor environment was investigated using exosomes isolated from gastric cancer cell lines MKN-28, MKN-45, and SGC-7901. Results show that exosomes derived from all of these cell lines changed the gene expression and cytokine secretion levels of CD8⁺ T cells. They also block cell cycle progression, induced apoptosis in CD8⁺ T cells. Image analysis of fluorescent labeled exosomes derived from three cell lines injected systemically into C57BL/6 mice revealed these exosomes primarily localize to the lungs. We further showed exosomes were mainly taken up by natural killer cells and macrophages in the lung. After long-term exposure to inject exosomes from MKN-45 cells, mice developed an immunosuppressive tumor microenvironment in the lung with increased frequency of effector memory CD4⁺ T and MDSC, decreased CD8⁺ T cell and NK frequency. This immune suppressive environment promotes gastric cancer lung metastasis. Lung metastasis sites developed after mice were exposed to exosomes isolated from all three gastric cancer cell lines when the mice were injected with MFC cells. Results suggest that exosomes derived from gastric cancer cells (especially MKN-45 and MKN-28) changed CD8⁺ T cell gene expression and cytokine secretion patterns to create an immunosuppressive condition for metastatic niche formation in the lung. Overall, this study provides new insights into how gastric cancer derived exosomes modulate the immune response to promote lung tumor metastasis.

Gastric cancer: epidemiology, biology, and prevention: a mini review

Gastric cancer is one of the most common causes of cancer-related mortality worldwide. The objective of this article is to review the epidemiology and biology of gastric cancer risk. This literature review explores the biological, clinical, and environmental factors that influence the rates of this disease and discuss the different intervention methods that may not only increase the awareness of gastric cancer but also increase screening in efforts to reduce the risk of gastric cancer. Helicobacter pylori infection is the primary risk factor for gastric cancer. Additional risk factors include geographical location, age, sex, smoking, socioeconomic status, dietary intake, and genetics. Primary and secondary prevention strategies such as dietary modifications and screenings are important measures for reducing the risk of gastric cancer. Interventions, such as H. pylori eradication through chemoprevention trials, have shown some potential as a preventative strategy. Although knowledge about gastric cancer risk has greatly increased, future research is warranted on the differentiation of gastric cancer epidemiology by subsite and exploring the interactions between H. pylori infection, genetics, and environmental factors. Better understanding of these relationships can help researchers determine the most effective intervention strategies for reducing the risk of this disease.

Mining topoisomerase isoforms in gastric cancer

DNA topoisomerases essentially remove topological strains generated during DNA replication, transcription, DNA repair, and other cytogenetic processes. However, distinct expression level and prognostic significance of individual topoisomerase isoforms in gastric cancer (GC) remain largely unexplored. In this study, we utilized Oncomine and Kaplan-Meier plotter database to detect the mRNA expression level of individual topoisomerase isoforms as well as assess their prognostic significance in GC patients. With the exception of TOP3B and TOP2B, levels of all topoisomerase isoforms were found to be elevated in GC patients when compared to the normal tissues. Elevated expression of TOP1 and TOP1MT was relevant to longer overall survival (OS) in GC and gastric intestinal type adenocarcinoma (GITA) patients, but not in diffuse gastric adenocarcinoma (DFA) patients. Increased expression of TOP2A and TOP2B was related to better OS in GC, as well as in GITA and DFA patients. In contrast, increased expression TOP3A and TOP3B was associated with shorter OS in GC, as well as in GITA and DFA patients. We also applied the Tumor IMmune Estimation Resource (TIMER) tool to assess the correlations between distinct topoisomerase isoforms and the infiltrating immune cell landscape. Furthermore, we found that down-regulating the expression of TOP3A by shRNA significantly inhibited the proliferation and colony formation in GC cells compared to control shRNA treated cells. Thus our study lays the framework for utilizing topoisomerases in better understanding the complexity and heterogeneity of GC and for developing strategies for novel customized therapy in GC patients.

Gastric Cancer: Epidemiology, Risk Factors, Classification, Genomic Characteristics and Treatment Strategies

Gastric cancer (GC) is one of the most common malignancies worldwide and it is the fourth leading cause of cancer-related death. GC is a multifactorial disease, where both environmental and genetic factors can have an impact on its occurrence and development. The incidence rate of GC rises progressively with age; the median age at diagnosis is 70 years. However, approximately 10% of gastric carcinomas are detected at the age of 45 or younger. Early-onset gastric cancer is a good model to study genetic alterations related to the carcinogenesis process, as young patients are less exposed to environmental carcinogens. Carcinogenesis is a multistage disease process specified by the progressive development of mutations and epigenetic alterations in the expression of various genes, which are responsible for the occurrence of the disease.

Glutathione Peroxidase 8 as a Prognostic Biomarker of Gastric Cancer: An Analysis of The Cancer Genome Atlas (TCGA) Data

Background

Glutathione peroxidase 8 (GPX8) has previously been shown to play a role in Keshan disease. In the present study, we explored the prognostic relevance of GPX8 expression in patients with gastric cancer (GC) based upon The Cancer Genome Atlas (TCGA) data.

Material/Methods

We assessed the relationship between the expression of GPX8 and clinicopathological findings in GC patients via logistic regression analyses, Kruskal-Wallis tests, and Wilcoxon signed-rank tests. We further assessed the prognostic relevance of specific variables using Kaplan-Meier and Cox regression analyses. We lastly conducted gene set enrichment analyses (GSEA).

Results

We detected a significant association between elevated GPX8 levels and more advanced GC tumor stage (OR=5.92 for I vs. IV), as well as more advanced T (OR=22.91 for T1 vs. T4) and N classification (OR=1.82 for N0 vs. N3). We found worse prognosis in patients expressing high levels of GPX8 relative to those with lower expression of this gene (P=0.021). In a univariate analysis, we found high GPX8 expression was strongly correlated with worse OS (hazard ratio [HR]: 1.05; 95% confidence interval [CI]: 1.01–1.08; P=0.018), and multivariate analysis confirmed that GPX8 expression independently predicts GC patient OS (HR: 1.04; CI: 1.00–1.08, P=0.041). GSEA revealed that elevated GPX8 expression was associated with enrichment of pathways consistent with MAPK signaling, JAK/STAT signaling, TGF-β signaling, melanoma, and basal cell carcinoma.

Conclusions

The expression of GPX8 may have prognostic relevance, being positively associated with worse OS in GC patients.

Plasma Exosomal Long Noncoding RNA lnc-SLC2A12-10:1 as a Novel Diagnostic Biomarker for Gastric Cancer

Purpose

Exosomes participate in cellular communications by transmitting active molecules, including long noncoding RNAs (lncRNAs) and are regarded as suitable candidates for disease diagnosis. This study aimed to identify gastric cancer (GC)-specific exosomal lncRNA and investigate the potential diagnostic value of plasma exosomal lncRNA in GC.

Patients and Methods

Exosomes from the culture media (CM) of four GC cells (GCCs) and human gastric epithelial cells were isolated. Exosomal RNA was extracted, and lncRNA microarray assay was performed to identify GC-specific exosomal lncRNAs. The expression levels of the candidate exosomal lncRNAs were validated in 120 subjects via quantitative reverse transcription PCR (qRT-PCR). The receiver operating characteristic (ROC) curve and area under curve were used to estimate the diagnostic capacity. We investigated the potential relationship between plasma exosomal lncRNA expression and the clinicopathological parameters of GC.

Results

A total of 199 exosomal lncRNAs were expressed at considerable higher levels in GCCs than those in normal controls, among which the top 10 upregulated lncRNAs were selected for further validation in cell, CM, and plasma. qRT-PCR revealed that lnc-SLC2A12-10:1 was remarkably upregulated in exosomes derived from patients with GC and GCCs. The area under the ROC curve was 0.776, which was higher than the diagnostic accuracies of CEA, CA 19-9, and CA72-4. The expression level of exosomal lnc-SLC2A12-10:1 was also significantly correlated with tumor size, TNM stage, lymph node metastasis, and degree of differentiation. The postoperative expression levels of exosomal lnc-SLC2A12-10:1 were lower compared with those of preoperative levels.

Conclusion

Our study suggested that exosomal lnc-SLC2A12-10:1 may be a potential noninvasive biomarker for the diagnosis and prognosis monitoring of GC. Further large-scale studies are necessary to validate its performance in GC progression.

TBX2 Expression predicts Tumor Recurrence and Adjuvant Chemotherapy Benefits in Gastric Cancer Patients following R0 Resection: a proposed approach for risk stratification

Aims: TBX2 is related to tumor progression and drug resistance. However, the roles of TBX2 in gastric cancer (GC) remain unclear. Our study aims at investigating the clinical roles of TBX2 in GC.

Methods: The protein expression levels of TBX2 in fresh GC tissue (n=20) were investigated with Western blotting analyses. The correlation between TBX2 expression and its prognostic significance was evaluated by immunohistochemical analyses of 401 patients. The survival benefit of postoperative adjuvant chemotherapy (PAC) for patients was evaluated.

Results: The expression of TBX2 was increased in GC tissue compared with adjacent paracancerous tissue (p=0.020). Immunohistochemistry demonstrated that TBX2 expression was significantly associated with lymphovascular invasion (p=0.024) and lymph node metastasis (p=0.044). A high level of TBX2 expression was an independent indicator of unfavorable recurrence-free and overall survival (p=0.002 and p=0.033, respectively). The prognostic model incorporating TBX2 expression exhibited greater predictive accuracy than the primary model. More importantly, the benefit of PAC noted in stage II/III GC patients with low TBX2 expression was superior to high TBX2 expression.

Conclusion: TBX2 may be not only a useful prognostic marker for GC but also a predictive biomarker of response to PAC in stage II/III GC patients. The current findings warrant further verification.

Human adipose-derived mesenchymal stem cells inhibit proliferation and induce apoptosis of human gastric cancer HGC-27 cells

The aim of this study was to explore the effects of human adipose-derived mesenchymal stem cells (ASCs) on the growth of gastric cancer cells in vivo and vitro and its mechanism. ASCs were isolated from abandoned adipose tissues, and the surface markers were identified by flow cytometry. In vitro experiments, HGC-27 cells cultured in ASCs-conditioned medium (CM) were assigned as the experimental group, while HGC-27 cells cultured in normal medium were as the control group. MTT and colony formation assays were performed to detect cell viability and colony formatting ability, respectively. Annexin-V/PI assay, Western blot, and caspase-3 enzyme activity assay were performed to detect cells apoptosis. The isolated ASCs could be differentiated into adipocytes and osteoblasts in vitro. Flow cytometry showed that CD73 and CD105 were positively expressed in HGC-27 cells. Compared with the mice injected HGC-27 cells only, the tumor formation in mice injected both ASCs and HGC-27 cells was significantly smaller (P < 0.05). The colony formation ability in experimental group was 40.09% smaller than control group (P < 0.05) and the cell apoptosis rate in experimental group was higher than the control group (P < 0.05). Furthermore, the expressions of cleaved PARP, cleaved caspase-3 proteins, and caspase-3 enzyme viability in experimental group were significantly higher than those of control group (P < 0.05). In conclusion, ASCs can effectively inhibit the growth of HGC-27 cells by inducing apoptosis.

GCdiscrimination: identification of gastric cancer based on a milliliter of blood

Gastric cancer (GC) continues to be one of the major causes of cancer deaths worldwide. Meanwhile, liquid biopsies have received extensive attention in the screening and detection of cancer along with better understanding and clinical practice of biomarkers. In this work, 58 routine blood biochemical indices were tentatively used as integrated markers, which further expanded the scope of liquid biopsies and a discrimination system for GC consisting of 17 top-ranked indices, elaborated by random forest method was constructed to assist in preliminary assessment prior to histological and gastroscopic diagnosis based on the test data of a total of 2951 samples. The selected indices are composed of eight routine blood indices (MO%, IG#, IG%, EO%, P-LCR, RDW-SD, HCT and RDW-CV) and nine blood biochemical indices (TP, AMY, GLO, CK, CHO, CK-MB, TG, ALB and γ-GGT). The system presented a robust classification performance, which can quickly distinguish GC from other stomach diseases, different cancers and healthy people with sensitivity, specificity, total accuracy and area under the curve of 0.9067, 0.9216, 0.9138 and 0.9720 for the cross-validation set, respectively. Besides, this system can not only provide an innovative strategy to facilitate rapid and real-time GC identification, but also reveal the remote correlation between GC and these routine blood biochemical parameters, which helped to unravel the hidden association of these parameters with GC and serve as the basis for subsequent studies of the clinical value in prevention program and surveillance management for GC. The identification system, called GC discrimination, is now available online at http://lishuyan.lzu.edu.cn/GC/.

Inhibitory effect of siRNA-Annexin A7 on growth, migration, and invasion in BGC823 cells and gastric cancer xenograftsin nude mice

OBJECTIVE

To explore the inhibitory effect of siRNA-Annexin A7 on growth, migration, and invasion of transplanted gastric cancer in nude mice.

METHODS

The siRNA sequence targeting to human Annexin A7 gene was designed, and based on that a pair of complementary oligonucleotides were synthesized, annealed, and cloned into plasmid pGenesil-1.1 to construct recombinant plasmid siRNA-Annexin A7. Transplanted gastric cancer model was established by injecting s.c. nude mice with human gastric cancer BGC823 cells, and siRNA-Annexin A7 was injected into the tumors formed. The nude mice were observed for clinical manifestation relying on the size and weight of transplanted tumors. The tumor tissue and angiogenesis were examined by pathologic sections. Flow cytometry was used to detect the changes of cell cycle. Western blot and qRT-PCR were used to analyze the expression of PCNA, P27, MMP-2, and TIMP-2.

RESULTS

Both the size and weight of transplanted tumors of nude mice injected with siRNA-Annexin A7 were less than those of control groups (P<0.05). The examination of pathologic sections showed that, compared with in the control group, obvious necrosis of tumor cells was observed in siRNA-Annexin A7 group. The cells in stage S were fewer in siRNA-Annexin A7 group than those in the other two groups, while the cells in stage G0/G1 were much more in siRNA-Annexin A7 group. The results of western blot and qRT-PCR confirmed that the expression of PCNA and MMP-2 was down-regulated, whereas the expression of p27 was up-regulated.

CONCLUSION

Gastric cancer xenografts were established in nude mice with human gastric cancer BGC823 cells. The volume and weight of tumor were decreased after inhibition of Annexin A7 expression in BGC823 cells. Tumor cells were arranged sparsely after inhibition of Annexin A7 expression in BGC823 cells. The siRNA-Annexin A7 inhibits Annexin A7 expression in transplanted gastric cancer of nude mice, and influences the growth, migration, and invasion of tumors by down-regulating the expression of PCNA and MMP-2, as well as up-regulating the expression of p27.

miR-449c-5p availability is antagonized by circ-NOTCH1 for MYC-induced NOTCH1 upregulation as well as tumor metastasis and stemness in gastric cancer

Gastric cancer (GC), identified as the most common gastrointestinal malignancy, is one of the primary causes of cancer-related mortality in the world. Although surgery and chemotherapy for GC treatment have been improved, the 5-year overall survival rate is still unsatisfactory. Circ-NOTCH1 is a novel circular RNA derived from its host gene NOTCH1, and has not been studied in any cancers. Here we explored the potential role and mediatory mechanism of circ-NOTCH1 in GC. In this study, circ-NOTCH1 exhibited increased expression in GC tissues and cells. Suppression of circ-NOTCH1 inhibited cell migration, invasion, tumor spheroids number, and side population ratio. Circ-NOTCH1 also promoted GC growth and metastasis in vivo. Additionally, it was found that circ-NOTCH1 could bind to miR-449c-5p. Circ-NOTCH1 promoted metastasis and stemness in GC through sponging miR-449c-5p. Subsequently, MYC was identified as a downstream gene of miR-449c-5p. MYC could bind to the promoter of NOTCH1 to regulate GC progression. Furthermore, rescue assays demonstrated that NOTCH1 knockdown reversed the effects of overexpression of MYC in metastasis and stemness in AGS cells/sh-circNOTCH1. Above findings explained that circ-NOTCH1 promoted metastasis and stemness in GC by targeting miR-449c-5p/MYC/NOTCH1 axis, suggesting the possibility of circ-NOTCH1 as a therapeutic marker for GC.

Exosomal Long Non-Coding RNA CEBPA-AS1 Inhibits Tumor Apoptosis and Functions as a Non-Invasive Biomarker for Diagnosis of Gastric Cancer

AIM

Traditional non-invasive diagnostic markers for gastric cancer (GC) exhibit insufficient sensitivity and specificity. Circulating exosomes are clinically useful non-invasive biomarkers for tumor diagnosis. In addition to their potential role in cancer biology, circulating long non-coding RNAs (lncRNAs) are a new class of promising cancer biomarkers. In the present study, we aimed to identify lncRNAs in circulating exosomes with potential as biomarkers for GC detection.

METHODS

We compared the expression of CEBPA-AS1 between GC cells and gastric epithelial cells. The biological function of exosomal CEBPA-AS1 was determined by cell phenotype experiments and rescue assays. We also compared the expression of CEBPA-AS1 in cancerous tissue from GC patients and corresponding adjacent normal tissues, as well as the expression of CEBPA-AS1 in plasma exosomes of GC patients and healthy controls. Diagnostic accuracy was assessed by the receiver operating characteristic (ROC) curve and area under the curve (AUC).

RESULTS

CEBPA-AS1 was highly expressed in both GC cells and in exosomes secreted by GC cells. In addition, CEBPA-AS1-containing exosomes secreted by GC cells could promote cell proliferation and inhibit apoptosis, thereby inducing the malignant behavior of GC cells. The level of CEBPA-AS1 was also significantly increased in tissues and plasma exosomes of GC patients. Stability tests showed that most plasma CEBPA-AS1 was encased in exosomes, thus avoiding degradation by RNases. We evaluated the diagnostic accuracy of exosome-derived CEBPA-AS1. The AUC value of CEBPA-AS1 in discriminating GC patients from healthy controls was 0.824, which was higher than the diagnostic accuracy of other traditional tumor biomarkers.

CONCLUSION

CEBPA-AS1-containing exosomes secreted from GC cells could promote cell proliferation, inhibit apoptosis, and induce GC progression, indicating that exosomal CEBPA-AS1 is involved in cell-to-cell communication in GC carcinogenesis. Exosomal CEBPA-AS1 is a promising new biomarker for clinical diagnosis of GC.

Incidence Rate of Gastric Cancer Adenocarcinoma in Patients With Gastric Dysplasia: A Systematic Review and Meta-Analysis

Several studies have reported the risk of progression to gastric adenocarcinoma (GAC) in patients with gastric dysplasia (GD); however, the findings are controversial. We performed a systematic review and meta-analysis to study the incidence rate of GAC among patients with GD. Using a comprehensive search strategy, we systematically searched online databases including PubMed, Scopus, EMBASE, Cochrane Library, and Web of Science databases for identifying all relevant original articles through inception until July 2018. Cochran Q and I tests were used to assess heterogeneities between included studies. The incidence rates of GAC and their corresponding 95% confidence intervals (CIs) were pooled using random-effect or fixed-effect models. Of the 1980 retrieved records, 30 eligible articles (61 studies) were included. The overall pooled incidence rate of GAC was 40.36 (95% CI, 27.08-55.71; I, 96.0%) cases per 1000 person-years in patients with GD. Subgroup analysis according to the type of GD indicated the highest incidence rate of GAC was 186.40 (95% CI, 106.63-285.60; I, 94.6%) per 1000 person-years among patients with high-grade dysplasia (HGD) lesions. Although the incidence rates of GAC in low-grade dysplasia (LGD) lesions and in nonclassified lesions were 11.25 (95% CI, 3.91-21.22; I, 89.3%), and 1.40 (95% CI, 0.00-9.71; I, 78.8%), respectively. Compared with patients with LGD lesions, progression rate from GD to GAC was roughly 16 times greater in patients with HGD lesions. As the majority of patients with GAC are diagnosed in an advanced stage our study suggests strict management of HGD lesions to prevent GAC.

GLI1 activation by non-classical pathway integrin αvβ3/ERK1/2 maintains stem cell-like phenotype of multicellular aggregates in gastric cancer peritoneal metastasis

Peritoneal metastasis is one of the most important causes of postoperative death in patients with gastric cancer, and the exact mechanism remains unclear. The proliferation of multicellular aggregates of exfoliated malignant gastric cells in the abdominal cavity is the focus of current research. However, the mechanism how gastric cancer multicellular aggregates survive remains unclear. In this study, we demonstrated that multicellular aggregates of exfoliated gastric cancer cells in the abdominal cavity expressed a stem cell-Like phenotype. We found that Integrin α_vβ₃ not only mediated adhesion of gastric cancer multicellular aggregates to form independent functional units, but also maintained their stem cell-like phenotype by the non-classical pathway Integrin α_vβ₃/ERK1/2/GLI1. In addition, ERK1/2 directly regulates the transcriptional activity of GLI1. GLI1 is a key effector of the Integrin α_vβ₃ pathway in regulating stem cell-like phenotype in multicellular aggregates. Our data indicates that although there is a crosstalk between the non-classical Integrin α_vβ₃ pathway and the classical Hedgehog pathway, the activation of GLI1 is almost independent of the Hedgehog pathway in multicellular aggregates of gastric cancer cells. Our study provides a basis for blocking GLI1 activity in the prevention and treatment of peritoneal metastases of gastric cancer.

Plasma long noncoding RNAs PANDAR, FOXD2-AS1, and SMARCC2 as potential novel diagnostic biomarkers for gastric cancer

Background

Gastric cancer is still a common cancer worldwide. Investigation of potential plasma biomarkers for gastric cancer diagnosis is essential for prevention strategies and early intervention for gastric cancer-control planning.

Objectives

This study was aimed to explore the lncRNAs' promoter of CDKN1A antisense DNA-damage-activated RNA (PANDAR), FOXD2-AS1, and SMARCC2 as potential novel diagnostic biomarkers for gastric cancer.

Method

109 gastric cancer patients and 106 healthy controls were involved in this study. Plasma lncRNAs PANDAR, FOXD2-AS1, and SMARCC2 were detected by real-time PCR. Student's t-test, Mann-Whitney U test, and Chi-square test were used to verify the differences of clinical variables between two groups. Receiver operating characteristic curve (ROC) was used to evaluate the diagnostic value of every biomarker. Multivariable analysis of risk factors for gastric cancer was performed using logistic regression analysis.

Results

There were significant differences in age, gender, carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 153 between gastric cancer and healthy controls (P<0.05). Compared with healthy subjects, the levels of plasma lncRNAs PANDAR, FOXD2-AS1, and SMARCC2 were all significantly higher in gastric cancer patients (P<0.05). These lncRNAs were significantly associated with clinicopathological parameters of gastric cancer, like pathological differentiation, TNM stage, and/or lymph nodes metastasis, and/or invasion depth (P<0.05). The AUC for lncRNA PANDAR was 0.767, for FOXD2-AS1 was 0.700, for SMARCC2 was 0.748, and the AUC of the combinative diagnostic value of these three lncRNAs was 0.839. Adjusted by other variables, these lncRNAs' expressions were significantly associated with gastric cancer.

Conclusions

Plasma lncRNAs PANDAR, FOXD2-AS1, and SMARCC2 might be appropriate diagnostic biomarkers for gastric cancer.

Cáncer gástrico: una enfermedad prevenible. Estrategias para intervención en la historia natural

El cáncer gástrico es un problema de salud pública. Las cifras de mortalidad y supervivencia son impresentables en nuestro país. En Colombia no existe ningún programa ni estrategias de diagnóstico temprano, ni tampoco es priorizado como un problema de salud. Los trabajos existentes demuestran que la mayoría de los pacientes cuando son diagnosticados presentan estadios avanzados. Un 90 % de los canceres gástricos se consideran consecuencia de un largo proceso inflamatorio sobre la mucosa gástrica. La infección por Helicobacter pylori es la principal etiología de la gastritis, la cual puede progresar a atrofia, metaplasia, displasia y cáncer. La atrofia gástrica establece un campo de cancerización más propenso a cambios moleculares y fenotípicos que terminan en un cáncer en crecimiento. Es claro que la historia natural proporciona un racional entendimiento clínico patológico para estrategias de prevención primaria y secundaria. Una evidencia bien establecida demuestra que la combinación de las estrategias primarias (erradicación del H. pylori) y secundarias (diagnóstico y seguimiento endoscópico de lesiones premalignas) pueden prevenir o limitar la progresión de la carcinogénesis gástrica. El riesgo de cáncer gástrico asociado con la gastritis por H. pylori puede ser estratificado de acuerdo con la gravedad y extensión de la atrofia de la mucosa gástrica. Esta aproximación está adaptada a diferentes países, de acuerdo con su incidencia específica de cáncer gástrico, condición socioeconómica y factores culturales, que requiere de la participación complementaria de los gastroenterólogos, los cirujanos, los oncólogos y patólogos. Frente a este problema de salud pública no hay ninguna acción por parte de las autoridades de salud ni del gremio médico. Por tanto, se revisan las estrategias de manejo que permitan intervenir la historia natural de la enfermedad con el objetivo de disminuir la incidencia y mortalidad. La implementación y estandarización de estas estrategias de manejo en nuestro medio podrán beneficiar a los pacientes con riesgo incrementado para cáncer gástrico y pueden implementarse (en países sin programas de tamizaje) de una forma racional, similar a como se está haciendo con el cáncer colorrectal, en todo el mundo.

Efficacy and safety of intensity-modulated radiation therapy versus three-dimensional conformal radiation treatment for patients with gastric cancer: a systematic review and meta-analysis

BACKGROUND

Radiation or radiochemotherapy is a common adjuvant therapy for gastric cancer. Intensity-modulated radiation therapy (IMRT) has been demonstrated to provide better dose conformity, allowing dose escalation and/or reduction of normal tissue exposure compared with three-dimensional conformal radiation treatment (3D-CRT). However, the efficacy of IMRT and 3D-CRT in gastric cancer remains controversial. This study aimed to compare the efficacy and safety of IMRT with those of 3D-CRT in treating patients with gastric cancer through conducting a meta-analysis of 3-year survival rates [overall survival (OS) and disease-free survival (DFS)], local control rates, and toxic event rates.

METHODS

Embase, PubMed, the Cochrane Library, and clinical trial databases were searched to identify the clinical trials of IMRT versus 3D-CRT for treating patients with gastric cancer. The obtained data of survival and safety were analyzed using the Stata 14.0 software.

RESULTS

A total of 9 controlled clinical studies, including 516 patients with gastric cancer, met the inclusion criteria and were included in this meta-analysis. The results of the meta-analysis showed that the 3-year OS rate was slightly higher in the IMRT group than in the 3D-CRT group, without any statistical significance. The 3-year local control rate was significantly higher in the IMRT group than in the 3D-CRT group. No significant difference in the 3-year DFS rate was found between the IMRT and 3D-CRT groups. Grade 2-4 toxicities were similar between the IMRT and 3D-CRT groups.

CONCLUSION

The findings suggested that IMRT might be superior to 3D-CRT in treating patients with gastric cancer in terms of local control rates without increasing toxicity.

Downregulation of IQGAP1 inhibits epithelial-mesenchymal transition via the HIF1α/VEGF-A signaling pathway in gastric cancer

As an oncogene, IQ-domain GTPase-activating protein 1 (IQGAP1) regulates the epithelial-mesenchymal transition (EMT) of several cancers, such as breast cancer, thyroid cancer, and esophageal squamous cell carcinoma. However, the role of the scaffold protein IQGAP1 on EMT in gastric cancer remains unclear. Therefore, the present work was performed to address the question. Our results showed that IQGAP1 expression is upregulated in human gastric cancer specimens and cell lines. Furthermore, IQGAP1 knockdown inhibited the migratory ability of gastric cancer cells and reduced the expression of mesenchymal phenotype markers, including Slug, β-catenin, Snail, Vimentin, and N-cadherin, as well as vascular endothelial growth factor-A (VEGF-A) secretion in gastric cancer cells. Conversely, IQGAP1 downregulation increased the epithelial phenotype marker E-cadherin. Furthermore, IQGAP1 silencing not only downregulated hypoxia-inducible transcription factor 1α (HIF1α) but also limited its translocation from the cytosol to the nucleus. Collectively, our results indicated that EMT was regulated by IQGAP1, which was associated with VEGF-A, since other data demonstrated that HIF1α was involved in VEGF-A expression. Therefore, we speculated that IQGAP1 regulated EMT of gastric cancer partially via the HIF1α/VEGF-A signaling pathway. IQGAP1 may serve as an effective therapeutic biomarker for gastric cancer.

The effect of Jianpi Yangzheng Xiaozheng Decoction and its components on gastric cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Jianpi Yangzheng Xiaozheng Decoction (JPYZXZ) is an empirical compound prescription based on the theory of traditional Chinese medicine. JPYZXZ, which is "Qi-invigorating, spleen-strengthening and stasis-removing," can improve the quality of life of gastric cancer patients and prolong their survival; however, the exact mechanism underlying the antitumor effects of this compound is still not clear.

AIM OF THE STUDY

The aim of this study is to clearly define the effect of JPYZXZ and its components, Jianpi Yangzheng Decoction (JPYZ) and Xiao Zheng San Jie Decoction (XZSJ), on inhibiting the progression of gastric cancer.

MATERIALS AND METHODS

The effect of JPYZXZ and its components on the motility of gastric cancer MGC-803 cells was measured by MTT, adhesion, transwell assays and wound-healing assays. JPYZXZ, JPYZ and XZSJ were administered to 615 mice with gastric cancer xenografts, and their effect on the inhibition of subcutaneous transplantation was analyzed. THP-1 monocyte cells were used to establish tumor-associated macrophage (TAM) models. The polarized state of the TAMs was detected by Flow Cytometry, ELISA and Immunohistochemistry. The mRNA and protein expression of tumor epithelial-mesenchymal transition (EMT) and TAM-related genes was determined by Real-time PCR and Western Blot, respectively.

RESULTS

We determined that both JPYZXZ and its components inhibited the progress of gastric cancer in vitro, and JPYZXZ was clearly more effective than JPYZ or XZSJ. The in vivo results demonstrated that the JPYZXZ and XZSJ group exhibited a significant decrease in the tumor weight compared to the control group. Further analysis indicated that JPYZXZ was more active than JPYZ or XZSJ in inhibiting the gastric cancer EMT transformation both in vivo and in vitro. However, JPYZ was more effective compared with JPYZXZ for inducing the phenotypic change in macrophages from M2 to M1.

CONCLUSIONS

Our results demonstrate that both JPYZXZ and its components prevent the progress of gastric cancer. JPYZXZ inhibits the gastric cancer EMT more effectively than JPYZ and XZSJ, but JPYZ primarily works to regulate the phenotypic change in macrophages from M2 to M1.

Prognostic values of signal transducers activators of transcription in gastric cancer

The signal transducers and activators of transcription genes family (STATs) have been well studied as prognostic predictors for various solid tumors, but their prognostic values in gastric cancer (GC) patients have not been fully elucidated. The 'Kaplan-Meier plotter' and multiple public available databases were used for the characterization of the prognostic roles of STATs family in GC. The results indicated that high mRNA expression of all individual STATs, except STAT3 and STAT6, were significantly associated with favorable overall survival (OS) in GC. Moreover, the prognostic values of STATs were further characterized in subtypes, including HER2 status, Lauren's classification, differentiation, and clinical stages. Moreover, the prognostic value of STATs signature was also characterized. Low risk group displayed a significantly favorable OS than high risk (HR: 1.71; 95% CI: 1.09-2.66, P=0.0184). In addition, STATs showed distinct expression between GC and normal groups. Meanwhile, comparable high correlation between STATs and tumor immune infiltrating cells (TIICs) was also observed. STAT4 displayed highest correlation with dendritic cells (correlation = 0.716, P=1.63e-59) and CD8⁺ T cells (correlation = 0.697, P=5.02e-55). In conclusion, our results suggest that all individual STATs, except STAT3 and STAT6, may act as prognostic markers in GC.

Palmitate acid promotes gastric cancer metastasis via FABP5/SP1/UCA1 pathway

Background

Gastric cancer (GC) has a clear predilection for metastasis toward omentum which is primarily composed of adipose tissue, combine with our previous research that long non-coding RNA Urothelial cancer associated 1 (UCA1) could promote the peritoneal metastasis of GC, we put forward the hypothesis that fatty acids (FAs) might contribute to these phenomena and a connection between FAs and UCA1 might exist.

Methods

TCGA database was applied to investigate the expression levels of UCA1 in GC tissues and normal gastric tissues and its correlation with GC patients’ survival. Transfection of siRNA was utilized to knockdown cellular levels of FA-binding protein 5 (FABP5), SP1, UCA1. Migration assay and invasion assay were performed to assess the biological effects of palmitate acid (PA), FABP5, SP1 and UCA1 on GC metastasis. The underlying mechanism was investigated via western blot, immunofluorescence (IF), semi-quantitative RT-PCR (sqRT-PCR) and quantitative RT-PCR (qRT-PCR) analysis.

Results

Here we demonstrated that PA could promote the nuclear transport of FABP5, which then increased the nuclear protein levels of SP1. Consequently, GC cellular expression levels of UCA1 were increased which promoted the metastatic properties of GC. Besides, the cellular levels of UCA1 in GC tumor tissues were significantly higher than that in normal tissues. Its levels in GC tumor tissues also negatively correlated with the prognosis of GC patients using TCGA database.

Conclusions

Our research revealed the potential tumor-promoting effect of FA transport protein FABP5. We also established a connection between non-coding RNA and FA metabolism, treatment targeted either to patients’ diets or FABP5 might improve the prognosis of GC patients.

Hsa_circ_0000467 promotes cancer progression and serves as a diagnostic and prognostic biomarker for gastric cancer

BACKGROUND

Emerging evidence indicates that dysregulation of circular RNAs (circRNAs) is implicated in the development of malignancies. However, the diagnostic value and functional role of circRNAs in gastric cancer (GC) remain largely elusive.

METHODS

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed to detect the expression of hsa_circ_0000467 in tissues, cell lines, and plasma. A receiver operating characteristic (ROC) curve was constructed to estimate the diagnostic value of hsa_circ_0000467. The association between the expression level of hsa_circ_0000467 and the clinicopathological features was analyzed. Moreover, cell functional assays were performed.

RESULTS

Hsa_circ_0000467 was significantly upregulated in GC tissue compared to adjacent nontumor tissue (n = 51, P < 0.05). Similar results were detected in the HGC-27, MGC-803, AGS, NUGC-3, GES-1 cell lines (n = 15, P < 0.001), and in the plasma samples from GC patients (n = 20, P < 0.05). The area under the ROC curve of hsa_circ_0000467 was 0.790, which is superior to commonly used biomarkers including CEA and CA-724. We found that the expression levels of hsa_circ_0000467 in the same patient were significantly lower after surgery (n = 20, P < 0.05). Moreover, the hsa_circ_0000467 expression level is closely associated with TNM stage. Additionally, Cox multivariate analysis showed that hsa_circ_0000467 is a novel independent prognostic factor. Furthermore, in vitro experiments demonstrated that knockdown of hsa_circ_0000467 markedly inhibited the proliferation, migration, and invasion of GC cells. Moreover, hsa_circ_0000467 silencing increased tumor apoptosis in vitro.

CONCLUSION

Hsa_circ_0000467 can act as a novel noninvasive biomarker for the diagnosis and prognosis of GC and may be a potential therapeutic target for GC.

A robust qualitative transcriptional signature for the correct pathological diagnosis of gastric cancer

BACKGROUND

Currently, pathological examination of gastroscopy biopsy specimens is the gold standard for gastric cancer (GC) diagnosis. However, it has a false-negative rate of 10-20% due to inaccurate sampling locations and/or insufficient sampling amount. A signature should be developed to aid the early diagnosis of GC using biopsy specimens even when they are sampled from inaccurate locations.

METHODS

We extracted a robust qualitative transcriptional signature, based on the within-sample relative expression orderings (REOs) of gene pairs, to discriminate both GC tissues and adjacent-normal tissues from non-GC gastritis, intestinal metaplasia and normal gastric tissues.

RESULTS

A signature consisting of two gene pairs for GC diagnosis was identified and validated in data of both biopsy specimens and surgical resection specimens pooled from publicly available datasets measured by different laboratories with different platforms. For gastroscopy biopsy specimens, 96.20% of 79 non-GC tissues were correctly identified as non-GC, and 96.84% of 158 GC tissues and six of seven adjacent-normal tissues were correctly identified as GC. For surgical resection specimens, 98.37% of 2560 GC tissues and 97.28% of 221 adjacent-normal tissues were correctly identified as GC. Especially, 97.67% of the 257 GC patients at stage I were exactly diagnosed as GC. We additionally measured 21 GC tissues from seven different GC patients, each with three specimens sampled from three tumor locations with different proportions of the tumor epithelial cell. All these GC tissues were correctly identified as GC, even when the proportion of the tumor epithelial cell was as low as 14%.

CONCLUSIONS

The qualitative transcriptional signature can distinguish both GC and adjacent-normal tissues from normal, gastritis and intestinal metaplasia tissues of non-GC patients even using inaccurately sampled biopsy specimens, which can be applied robustly at the individual level to aid the early GC diagnosis.

CD36 mediates palmitate acid-induced metastasis of gastric cancer via AKT/GSK-3β/β-catenin pathway

BACKGROUND

Gastric cancer (GC) has a clear predilection for metastasis toward the omentum which is primarily composed of adipose tissue, indicating that fatty acids may contribute to this phenomenon. However their function remains poorly understood in GC. In this study, we investigated the role of palmitate acid (PA) and its cellular receptor CD36 in the progression of GC.

METHODS

Immunohistochemical (IHC) staining was performed to detect CD36 expression in GC tissues and its clinical significance was determined statistically. CD36 over-expression and knock-down expression cell models were developed and tested in vitro. Wound-healing assays, migration assays, and invasion assays were performed and peritoneal implants into nude mice were done to assess the biological effects of PA and CD36. The underlying mechanisms were investigated using western blot, immunofluorescence (IF), quantitative real-time PCR (qRT-PCR) and antibody blocking assays.

RESULTS

PA promoted the metastasis of GC by phosphorylation of AKT, which facilitated the nuclear localization of β-catenin through inactivation of GSK-3β via phosphorylation. This tumor-promoting effect of PA was mediated by CD36, a cell surface receptor of fatty acids (FAs). The higher the CD36 expression levels in GC tissues correlated with the poorer the prognosis of patients according to the TCGA database, the GEO database and our own clinical data.

CONCLUSIONS

Our experiments established CD36 as a key mediator of FA-induced metastasis of GC via the AKT/GSK-3β/β-catenin signaling pathway. CD36 might, therefore, constitute a potential therapeutic target for clinical intervention in GC.