Gastric cancer: current and evolving treatment landscape

Natural sapogenins as potential inhibitors of aquaporins for targeted cancer therapy: computational insights into binding and inhibition mechanism

Aquaporins (AQPs) are membrane proteins that facilitate the transport of water and other small molecules across biological membranes. AQPs are involved in various physiological processes and pathological conditions, including cancer, making them as potential targets for anticancer therapy. However, the development of selective and effective inhibitors of AQPs remains a challenge. In this study, we explored the possibility of using natural sapogenins, a class of plant-derived aglycones of saponins with diverse biological activities, as potential inhibitors of AQPs. We performed molecular docking, dynamics simulation and binding energy calculation to investigate the binding and inhibition mechanism of 19 sapogenins against 13 AQPs (AQP0-AQP13) that are overexpressed in various cancers. Our results showed that out of 19 sapogenins, 8 (Diosgenin, Gitogenin, Tigogenin, Ruscogenin, Yamogenin, Hecogenin, Sarsasapogenin and Smilagenin) exhibited acceptable drug-like characteristics. These sapogenin also exhibited favourable binding affinities in the range of -7.6 to -13.4 kcal/mol, and interactions within the AQP binding sites. Furthermore, MD simulations provided insights into stability and dynamics of the sapogenin-AQP complexes. Most of the fluctuations in binding pocket were observed for AQP0-Gitogenin and AQP4-Diosgenin. However, remaining protein-ligand complex showed stable root mean square deviation (RMSD) plots, strong hydrogen bonding interactions, stable solvent-accessible surface area (SASA) values and minimum distance to the receptor. These observations suggest that natural sapogenin hold promise as novel inhibitors of AQPs, offering a basis for the development of innovative therapeutic agents for cancer treatment. However, further validation of the identified compounds through experiments is essential for translating these findings into therapeutic applications.

Effect of antiemetics on zolbetuximab-induced gastric injury and emesis in ferrets

Claudin-18 splice variant 2 (CLDN18.2), a tight junction protein, is a highly cell type-specific antigen that is expressed by differentiated gastric mucosa cells. The expression of CLDN18.2 in gastric mucosa cells may be retained upon malignant transformation and is displayed on the surface of several tumors, including gastric/gastroesophageal junction adenocarcinoma. Zolbetuximab is a genetically engineered, highly purified chimeric (mouse/human IgG1) antibody directed against CLDN18.2. Nausea and vomiting were observed as adverse events of zolbetuximab. To investigate the mechanism of nausea and vomiting in humans, we evaluated emesis (retching and vomiting) and conducted histopathologic assessment in ferrets after the administration of zolbetuximab. Emesis was frequently observed in all ferrets treated with zolbetuximab in the first hour after administration. Histopathologic assessment revealed the surface of the gastric mucosa was the primary site of emesis-associated tissue damage. The effect of antiemetics (dexamethasone, ondansetron, fosaprepitant, and olanzapine) on emesis induced by zolbetuximab was investigated. Fosaprepitant showed suppressive effects on emesis, and use of dexamethasone or concomitant use of fosaprepitant with other antiemetics tended to alleviate gastric tissue damage. The onset of emesis in humans receiving zolbetuximab may be associated with damage in the gastric mucosa, and antiemetics may mitigate gastrointestinal adverse events.

Exploring the Mechanisms of Traditional Chinese Herbal Therapy in Gastric Cancer: A Comprehensive Network Pharmacology Study of the Tiao-Yuan-Tong-Wei decoction

The use of herbal medicine as an adjuvant therapy in the management of gastric cancer has yielded encouraging outcomes, notably in enhancing overall survival rates and extending periods of disease remission. Additionally, herbal medicines have demonstrated potential anti-metastatic effects in gastric cancer. Despite these promising findings, there remains a significant gap in our understanding regarding the precise pharmacological mechanisms, the identification of specific herbal compounds, and their safety and efficacy profiles in the context of gastric cancer therapy. In addressing this knowledge deficit, the present study proposes a comprehensive exploratory analysis of the Tiao-Yuan-Tong-Wei decoction (TYTW), utilizing an integrative approach combining system pharmacology and molecular docking techniques. This investigation aims to elucidate the pharmacological actions of TYTW in gastric pathologies. It is hypothesized that the therapeutic efficacy of TYTW in counteracting gastric diseases stems from its ability to modulate key signaling pathways, thereby influencing PIK3CA activity and exerting anti-inflammatory effects. This modulation is observed predominantly in pathways such as PI3K/AKT, MAPK, and those directly associated with gastric cancer. Furthermore, the study explores how TYTW's metabolites (agrimoniin, baicalin, corosolic acid, and luteolin) interact with molecular targets like AKT1, CASP3, ESR1, IL6, PIK3CA, and PTGS2, and their subsequent impact on these critical pathways and biological processes. Therefore, this study represents preliminary research on the anticancer molecular mechanism of TYTW by performing network pharmacology and providing theoretical evidence for further experimental investigations.

Platelet-lymphocyte ratio predicts chemotherapy response and prognosis in patients with gastric cancer undergoing radical resection

Background

Amounting literatures have reported the significance of systemic inflammatory markers for evaluating tumor prognosis. But few studies have systematically compared their superiority and their impact on adjuvant chemotherapy.

Aims

We aimed to investigate the ability of inflammatory markers to predict the efficacy of chemotherapy in GC patients undergoing radical therapy and to identify an effective methodology based on the study's findings that would enable clinicians to differentiate between chemotherapy-responsive populations.

Methods

We retrospectively enrolled 730 GC patients who underwent radical gastrectomy. Fibrinogen (FIB), platelet-lymphocyte ratio (PLR), systemic inflammation response index (SIRI), prognostic nutritional index (PNI), systemic immune-inflammation index (SII), neutrophil-lymphocyte ratio (NLR) and lymph node ratio (LNR) were grouped according to cutoff values. Their clinical significance for GC prognosis was determined by multivariate COX regression analysis in the 730 GC patients and high/low PLR status subgroups. Cases were divided into four groups according to PLR status and adjuvant chemotherapy status and survival was compared among groups.

Results

Multivariate analysis showed that PLR was an independent prognostic factor for overall survival (OS) and disease-free survival (DFS) of GC patients. Adjuvant chemotherapy improved survival more significantly in patients with low PLR than that with high PLR. Among patients receiving adjuvant chemotherapy, low PLR was significantly associated with prolonged survival in TNM stage II, but not in TNM stage III.

Conclusion

Preoperative high PLR is an independent risk factor for GC patients undergoing radical gastrectomy and adversely affects the postoperative chemotherapy effect.

Deciphering the oncogenic landscape: Unveiling the molecular machinery and clinical significance of LncRNA TMPO-AS1 in human cancers

The in-depth exploration of long non-coding RNAs (lncRNAs) reveals their pivotal and diverse roles in various disorders, particularly cancer. Within this intricate landscape, thymopoietin-antisense RNA-1 (TMPO-AS1) emerges as a noteworthy instigator of oncogenesis in humans. This exhaustive review seeks to intricately unravel the present understanding of TMPO-AS1, emphasizing its molecular foundations and highlighting its clinical applications in the realm of cancer research. TMPO-AS1 consistently exhibits heightened expression across a spectrum of cancer types, encompassing lung, colorectal, breast, cervical, bladder, pancreatic, hepatocellular, gastric, ovarian, and osteosarcoma. Elevated levels of TMPO-AS1 are intricately linked to unfavorable prognoses, accompanied by distinctive clinical and pathological characteristics. Functionally, TMPO-AS1 showcases its prowess in enhancing cancer cell migration, invasion, proliferation, and orchestrating epithelial-mesenchymal transition (EMT) through a myriad of molecular mechanisms. These mechanisms entail intricate interactions with proteins, microRNAs, and intricate signaling pathways. Furthermore, TMPO-AS1 is intricately involved in regulating critical cellular processes, including apoptosis and the cell cycle. The mounting evidence converges towards the potential of TMPO-AS1 serving as a diagnostic and prognostic biomarker, further entwined with its potential role in influencing chemoresistance in cancer. This potential is underscored by its consistent associations with clinical outcomes and treatment responses. This comprehensive investigation not only consolidates our existing knowledge of TMPO-AS1's multifaceted roles but also sheds illuminating insights on its profound significance in the intricate landscape of cancer biology, paving the way for potential applications in clinical practice.

Immunohistochemical characteristics and potential therapeutic regimens of hepatoid adenocarcinoma of the stomach: a study of 139 cases

Hepatoid adenocarcinoma of stomach (HAS) is a special subtype of gastric cancer with poor prognosis. Immunohistochemical analysis could provide important clues for the treatment of HAS. A total of 159 patients were diagnosed as HAS and 139 were enrolled in this study. Statistical differences were determined using relative test methods and survival analyses were performed by the Kaplan-Meier method to find survival differences. All tumors in this study were negative for Epstein-Barr virus-encoded small RNAs (EBERs) and almost all showed no loss of mismatch repair (MMR) proteins and were positive for alpha fetoprotein (AFP or spalt like transcription factor 4 (SALL4). About half of the tumors had a positive programmed death-ligand 1 combined positive score (CPS) and 17.3% were positive for human epidermal growth factor receptor 2 (HER2). In addition, there was a relatively high proportion of cmet expression. We also found that HAS patients with recurrent disease treated by emerging therapy had a better survival than those treated with traditional chemotherapy (p = 0.002, median recurrence-to-death survival: 23 months versus 6 months); HAS patients who received anti-HER2 therapy or harbored MMR deficiency had favorable prognosis. Overall, high proportions of MMR protein proficiency, positivity for AFP or SALL4, overexpression of HER2, CPS and cmet, as well as negative EBER findings, are distinctive characteristics of HAS patients. While negative EBER and MMR proficiency indicate molecular features of HAS, positivity for AFP or SALL4 could aid in the diagnosis of HAS. In addition, HAS patients could benefit from anti-HER2 therapy, immunotherapy, and anti-angiogenesis therapy.

Nomogram based on clinical characteristics for predicting overall survival in gastric cancer patients with preoperative anemia

BACKGROUND

Preoperative anemia is associated with increased postoperative morbidity and mortality and increased perioperative transfusion risk. For surgical patients, this affects physical and cognitive ability and quality of life, but it is an important and modifiable risk factor.

AIM

To determine the effect of preoperative anemia on the prognosis of gastric cancer (GC) patients and generate a prognostic nomogram to predict the postoperative overall survival (OS) of GC patients with preoperative anemia.

METHODS

Clinicopathological and follow-up data of GC patients treated at Zhejiang Provincial People's Hospital (China) from 2010 to 2015 were collected. Independent prognostic factors were screened by univariate and multivariate Cox regression analyses. Then, these factors were used to construct a nomogram to predict 1-, 3-, and 5-year postoperative OS in preoperative anemic GC patients. The nomogram was assessed by calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA).

RESULTS

Nine hundred and sixty GC patients were divided into two groups (preoperatively anemic and nonanemic), and postoperative survival analysis was performed on both groups, yielding a shorter postoperative survival for preoperatively anemic patients than for nonanemic patients. A total of 347 GC patients with preoperative anemia were included. Age, preoperative alpha-fetoprotein level, monocyte count, lymphocyte count, clinicopathological stage, liver metastasis, and GC type were identified as independent prognostic factors for OS. The area under the ROC curve (AUC) of the nomogram for predicting 1-, 3-, and 5-year OS was 0.831, 0.845, and 0.840, respectively, for the training cohort, and the corresponding AUC values in the validation cohort were 0.827, 0.829, and 0.812, respectively. Calibration curves and DCA indicated good performance of the nomogram.

CONCLUSION

In all, we have successfully produced and verified a useful nomogram for predicting OS in GC patients with preoperative anemia. This nomogram based on a variety of clinicopathological indices can provide an effective prognostic assessment and help clinicians choose an appropriate treatment strategy for GC patients with preoperative anemia.

Feasibility evaluation of hsa_circ_0005480 as an auxiliary diagnostic and prognostic indicator for gastric cancer

Aim: To explore the potential role of hsa_circ_0005480 as a marker for gastric cancer (GC). Methods: GSE83521, GSE93541 and GSE131414 were combined to screen the most potential circRNAs in GC. The expression of hsa_circ_0005480 was verified in clinical plasma samples and its diagnostic performance was evaluated by receiver operating characteristic (ROC) curve. Results: Hsa_circ_0005480 was upregulated in newly diagnosed GC patients, and performed well in distinguishing GC patients from healthy donors. Combination of hsa_circ_0005480 with traditional laboratory metrics showed increased sensitivity and accuracy than standalone application. In addition, hsa_circ_0005480 expression was low in GC patients treated with chemoradiotherapy or surgery, and decreased dynamically about 1 week postoperatively. Conclusion: Hsa_circ_0005480 may prove to be a marker for auxiliary diagnosis and prognostic evaluation of GC.

The Expression of ARMCX1 in Gastric Cancer Contributes to Prognosis and Influences Chemotherapy

The altered expression of ARMCX1 in patients with gastric cancer has been reported frequently, yet its correlation to prognosis and chemotherapy needs to be unveiled. In combination of the gene expression data retrieved from TCGA database and bioinformatic analysis, this study discovered 590 differentially expressed genes in the cancerous biopsies isolated from gastric patients, compared with controls. Among which, ARMCX1 exhibited great potential to serve as a prognostic biomarker for gastric patients; furthermore, patients with low expression of ARMCX1 could be more sensitive to these 9 chemotherapeutic agents: A-770041, AMG-706, ATRA, BEZ235, bortezomib, CGP60474, dasatinib, HG-64-1, and pazopanib, rather than the other chemotherapeutic agents. This study helps the improvement of evaluating the prognosis of gastric cancer patients, and would help optimize chemotherapeutic strategies in consideration of the expression of ARMCX1.

High Expression of UPK3A Promotes the Progression of Gastric Cancer Cells by Inactivating p53 Pathway

Background

Gastric cancer is a common gastrointestinal tract cancer and is a considerable health burden worldwide. TCGA analysis found Uroplakin 3A (UPK3A) was upregulated in gastric cancer tissues. Our study was designed to investigate the underlying mechanism of Uroplakin 3A (UPK3A) in gastric cancer.

Methods

Data from TCGA database were used to assess the expression, and Kaplan-Meier plotter analysis was used to assess the prognosis value of UPK3A. Furthermore, there are effects of UPK3A silencing on the activity, proliferation, migration, and invasion of human gastric cancer cells (SNU-216 and HGC-27) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, wound healing, and Transwell assays. In addition, the expression of UPK3A, p53, KLF4, ZMAT3, MDM2, and SP1 was detected by qRT-PCR and Western blot assay.

Results

UPK3A was markedly upregulated in gastric cancer tissues compared to that in normal tissues, and patients with high UPK3A level showed poor prognosis. UPK3A was highly expressed in human gastric cancer cell lines compared to that in a normal human gastric epithelial cell line. Silencing of UPK3A inhibited the proliferation, migration, and invasion of gastric cancer cells. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that UPK3A was involved in the p53 signaling pathway. UPK3A suppressed the activation of p53 signaling pathway, and treatment with Pifithrin-α (an inhibitor of the p53 signaling pathway) or silencing of p53 significantly reversed the effect of UPK3A silencing on the expression of p53, KLF4, ZMAT3, MDM2, and SP1.

Conclusion

Our findings showed that UPK3A promotes the progression of gastric cancer by regulating the p53 signaling pathway and could be a potential therapeutic target for gastric cancer.

Structured and shared CT radiological report of gastric cancer: a consensus proposal by the Italian Research Group for Gastric Cancer (GIRCG) and the Italian Society of Medical and Interventional Radiology (SIRM)

OBJECTIVES

Written radiological report remains the most important means of communication between radiologist and referring medical/surgical doctor, even though CT reports are frequently just descriptive, unclear, and unstructured. The Italian Society of Medical and Interventional Radiology (SIRM) and the Italian Research Group for Gastric Cancer (GIRCG) promoted a critical shared discussion between 10 skilled radiologists and 10 surgical oncologists, by means of multi-round consensus-building Delphi survey, to develop a structured reporting template for CT of GC patients.

METHODS

Twenty-four items were organized according to the broad categories of a structured report as suggested by the European Society of Radiology (clinical referral, technique, findings, conclusion, and advice) and grouped into three "CT report sections" depending on the diagnostic phase of the radiological assessment for the oncologic patient (staging, restaging, and follow-up).

RESULTS

In the final round, 23 out of 24 items obtained agreement ( ≥ 8) and consensus ( ≤ 2) and 19 out 24 items obtained a good stability (p > 0.05).

CONCLUSIONS

The structured report obtained, shared by surgical and medical oncologists and radiologists, allows an appropriate, clearer, and focused CT report essential to high-quality patient care in GC, avoiding the exclusion of key radiological information useful for multidisciplinary decision-making.

KEY POINTS

• Imaging represents the cornerstone for tailored treatment in GC patients. • CT-structured radiology report in GC patients is useful for multidisciplinary decision making.

Establishment of gastric signet ring cell carcinoma organoid for the therapeutic drug testing

Signet ring cell carcinoma (SRCC) has specific oncogenesis and phenotypic and treatment resistance heterogeneity. Systemic therapies are often ineffective, and predictive biomarkers to guide treatment are urgently needed. Tumor organoids have recently emerged as an ideal model for drug testing and screening. Here, we report gastric organoids established from tumor tissues comprising four SRCCs and eight non-SRCCs. Tumor organoids demonstrated different growth characteristics and morphologies. Changes in the original tumor genome were maintained during long-term culture from whole-exome sequencing (WES) analysis. Immunohistochemistry and H&E staining showed that the tissue characteristics of the primary tumor could be recapitulated. In addition, organoid lines successfully formed tumors in immunodeficient mice and maintained tumorigenic character. Different responses to 5-fluorouracil, oxaliplatin, docetaxel and irinotecan treatment were observed in SRCC and non-SRCC organoids. These results demonstrate that gastric organoid drug models, including SRCC, were highly similar to the original tumors in phenotypic and genotypic profiling and could be as living biomarkers for drug response testing.

Treatment Patterns and Outcomes in Chinese Patients with Gastric Cancer by HER2 Status: A Noninterventional Registry Study (EVIDENCE)

BACKGROUND

Real-world safety and effectiveness data for trastuzumab plus chemotherapy treatment of patients with HER2-positive metastatic gastric cancer (mGC) in China are lacking.

PATIENTS AND METHODS

EVIDENCE was a prospective, multicenter, noninterventional registry study evaluating the safety and effectiveness of trastuzumab in five cohorts of Chinese patients with gastric cancer, stratified by HER2 status and trastuzumab treatment. Effectiveness was analyzed for cohorts I (HER2-positive, trastuzumab treated), II (HER2-positive, trastuzumab untreated), and IV (HER2-negative, trastuzumab untreated); trastuzumab-related adverse events (AEs) were analyzed for cohort I.

RESULTS

Cohorts I, II, and IV included 174, 113, and 422 patients, respectively. Most patients received first-line chemotherapy (87.6%). Median overall survival (OS1) for first-line treatment was 22.3, 17.2, and 17.4 months in cohorts I, II, and IV, respectively. After excluding patients who had surgery, respective median OS1 was 19.9, 15.3, and 12.9 months. Respective first-line progression-free survival (PFS1) was 8.2, 6.9, and 6.2 months; and respective first-line response rates (RR) were 51.7%, 18.4%, and 32.8%. Cohort I was significantly favored over cohort II for propensity score-matched first-line median OS1 (hazard ratio [HR], 0.61), PFS1 (HR, 0.64), and RR (odds ratio, 4.93). Trastuzumab-related AEs, grade 3-5 AEs, serious AEs, and AEs with a fatal outcome occurred in 23.6%, 3.4%, 2.3%, and 0.6% of cohort I patients, respectively.

CONCLUSION

Safety profiles were consistent with those known for trastuzumab and chemotherapy; trastuzumab treatment improved outcomes. Our study provides real-world data supporting first-line trastuzumab plus chemotherapy in Chinese patients with HER2-positive mGC.

IMPLICATIONS FOR PRACTICE

This prospective, noninterventional registry study aimed to provide safety and effectiveness data for the use of trastuzumab in combination with chemotherapy in Chinese patients with HER2-positive metastatic gastric cancer (mGC) from the real-world clinical setting. Trastuzumab plus first-line chemotherapy was shown to be safe and to improve outcomes when compared with patients treated with chemotherapy alone. Trastuzumab was effective within a range of treatment regimens; subgroup analysis showed that trastuzumab paired most effectively with the XELOX regimen. This study provides real-world clinical safety and effectiveness data supporting the use of trastuzumab in the treatment of Chinese patients with HER2-positive mGC.

A novel mechanism driving poor-prognostic gastric cancer: overexpression of the transcription factor Krüppel-like factor 16 promotes growth and metastasis of gastric cancer through regulating the Notch pathway

Gastric cancer (GC) is one of the most common malignant tumors worldwide and has high rates of morbidity and mortality. This study investigated the role of Krüppel-like factor 16 (KLF16) in GC. Real-time polymerase chain reaction, Western blotting, and immunohistochemistry were used to examine the expression of KLF16 in gastric cells and tissues. Gene overexpression and silencing were applied to study the involvement of KLF16 in GC cell growth and metastasis along with its underlying mechanism. The results indicate that KLF16 overexpression is significantly associated with nodal status, distant metastasis, staging, degree of differentiation, vascular invasion, and patient survival. Multivariate Cox proportional hazards regression model analysis revealed that the overexpression of KLF16 is an independent prognostic biomarker of GC. The in vitro study revealed that up-regulated KLF16 accelerates cell growth and metastasis, whereas the inhibition of KLF16 suppresses these cellular activities. The results of an animal study also indicated that the overexpression and silencing of KLF16 accelerate and repress xenograft proliferation and metastasis. Further studies of affected cell growth and metastasis revealed that KLF16 modulates the cell cycle and epithelial-mesenchymal transition through transcriptional regulation of microfibrillar-associated protein 5. Collectively, these results reveal that KLF16 overexpression is a potential prognostic biomarker and therapeutic target for the treatment of GC.

TTC36 inactivation induce malignant properties via Wnt-β-catenin pathway in gastric carcinoma

Objective: Tetratricopeptide repeat (TRP)-mediated cofactor proteins are involved in a wide range of cancers. TTC36 is little studied member of TRP subfamily. This study aimed to investigate the role of TTC36 in human gastric carcinoma (GC) and explore the potential underlying mechanisms.

Methods: The analysis of TTC36 differential expression in GC was conducted using data from TCGA and a human tissue microarray. And effects of TTC36 expression on the prognosis of patients with gastric carcinoma were analyzed using the data from the GEO database. Lentivirus was transfected into the cell lines of AGS and BGC823 to construct overexpression and knocked down TTC36 cell model respectively. The effect of TTC36 expression on the growth, apoptosis and cell cycle of cells was explored in vitro. Downstream molecules were detected by western blotting. GSEA predicted signal pathway and related proteins were then detected.

Results: TTC36 expression in human GC tissues was found significantly lower than that in adjacent normal tissues and closely related to clinical prognosis. The overexpression of TTC36 notably inhibited tumor progression, cell cycle G1/S transfer and increased apoptosis in AGS cells. Conversely, the opposite effects were observed when TTC36 was suppressed in BGC823 cells. The expression of cleaved caspase3, Survivin, cyclin D1 and c-Myc were consistent with the phenotype in TTC36 operated GC cell lines. Intriguingly, GSEA analysis predicted Wnt-β-catenin pathway involved in TTC36 induced effects in GC cells, expression of β-catenin and downstream molecules such as TCF4, c-jun and pAKT were found negative related to TTC36 expression in GC cells. Notably, treatment with the Wnt/β-catenin inhibitor XAV939 dramatically attenuated the effects of TTC36 in GC cells.

Conclusion: These results signify a critical role for TTC36 as a tumor suppressor in gastric carcinoma via regulating Wnt-β-catenin pathway.

BTEB2-Activated lncRNA TSPEAR-AS2 Drives GC Progression through Suppressing GJA1 Expression and Upregulating CLDN4 Expression

Long non-coding RNAs (lncRNAs) are characterized as key layers of the genome in various cancers. TSPEAR-AS2 was highlighted to be a candidate lncRNA potentially involved in gastric cancer (GC) progression. However, the clinical significance and mechanism of TSPEAR-AS2 in GC required clarification. The clinical significance of TSPEAR-AS2 was elucidated through Kaplan-Meier Plotter. The mechanism of TSPEAR-AS2 in GC was clarified in vitro and in vivo using luciferase reporter, chromatin immunoprecipitation, RNA immunoprecipitation assays, and animal models. TSPEAR-AS2 elevation was closely correlated with overall survival of GC patients. A basic transcription element-binding protein 2 (BTEB2)-activated TSPEAR-AS2 model was first explored in this study. TSPEAR-AS2 silencing substantially reduced tumorigenic capacities of GC cells, while TSPEAR-AS2 elevation had the opposite effect. Mechanistically, TSPEAR-AS2 bound with both polycomb repressive complex 2 (PRC2) and argonaute 2 (Ago2). TSPEAR-AS2 knockdown significantly decreased H3K27me3 levels at promoter regions of gap junction protein alpha 1 (GJA1). Ago2 was recruited by TSPEAR-AS2, which was defined to sponge miR-1207-5p, contributing to the repression of claudin 4 (CLDN4) translation. The axis of EZH2/GJA1 and miR-1207-5p/CLDN4 mediated by BTEB2-activated-TSPEAR-AS2 plays an important role in GC progression, suggesting a new therapeutic direction in GC treatment.

Aberrant Expression of NCAPG is Associated with Prognosis and Progression of Gastric Cancer

Introduction

Gastric cancer (GC), one of the most prevalent malignancies, is the third-leading cause of cancer-related deaths globally. The aim of this study is to investigate the involvement of non-structural maintenance of chromosomes condensin I complex subunit G (NCAPG) in the prognosis of GC.

Methods

Western blotting and immunostaining were employed to measure the NCAPG level in gastric tissues and cells. Kaplan–Meier analysis was applied to analyze the prognostic value of NCAPG in GC. RNA interference was applied to investigate the influence of the NCAPG silencing on GC cell growth and spread.

Results

NCAPG overexpression was associated with several clinicopathologic characteristics, including nodal status (P = 0.0378), distant metastasis (P = 0.0088), staging (P = 0.0230), vascular invasion (P = 0.0012), and disease-free survival (P = 0.004). Kaplan–Meier analysis revealed that NCAPG overexpression was positively correlated to poor GC patients disease-free and overall survival (P = 0.004 and P < 0.001, respectively). Univariate Cox regression analysis showed that the overexpression of NCAPG was a prognostic biomarker of GC (P = 0.005). In cultured GC cells, the knockdown of NCAPG suppressed cell proliferation, migration and invasion. Meanwhile, further studies revealed that the NCAPG silencing induces the G0/G1 cell cycle arrest and accordingly represses cell division. Finally, Western blotting showed that NCPAG knockdown dysregulated cell cycle- and epithelial–mesenchymal transition-related molecules.

Conclusion

Overall, the results reveal that NCAPG overexpression is a candidate prognostic biomarker and potential therapeutic target in GC.

DNA methylation data-based molecular subtype classification and prediction in patients with gastric cancer

Background

Genetic and epigenetic alterations have been indicated to be closely correlated with the carcinogenesis, DNA methylation is one of most frequently occurring molecular behavior that take place early during this complicated process in gastric cancer (GC).

Methods

In this study, 398 samples were collected from the cancer genome atlas (TCGA) database and were analyzed, so as to mine the specific DNA methylation sites that affected the prognosis for GC patients. Moreover, the 23,588 selected CpGs that were markedly correlated with patient prognosis were used for consistent clustering of the samples into 6 subgroups, and samples in each subgroup varied in terms of M, Stage, Grade, and Age. In addition, the levels of methylation sites in each subgroup were calculated, and 347 methylation sites (corresponding to 271 genes) were screened as the intrasubgroup specific methylation sites. Meanwhile, genes in the corresponding promoter regions that the above specific methylation sites were located were performed signaling pathway enrichment analysis.

Results

The specific genes were enriched to the biological pathways that were reported to be closely correlated with GC; moreover, the subsequent transcription factor enrichment analysis discovered that, these genes were mainly enriched into the cell response to transcription factor B, regulation of MAPK signaling pathways, and regulation of cell proliferation and metastasis. Eventually, the prognosis prediction model for GC patients was constructed using the Random Forest Classifier model, and the training set and test set data were carried out independent verification and test.

Conclusions

Such specific classification based on specific DNA methylation sites can well reflect the heterogeneity of GC tissues, which contributes to developing the individualized treatment and accurately predicting patient prognosis.

DNA Methylation Profiling of hTERT Gene Alongside with the Telomere Performance in Gastric Adenocarcinoma

PURPOSE

Epigenetic modification including of DNA methylation, histone acetylation, histone methylation, histon phosphorylation and non-coding RNA can impress the gene expression and genomic stability and cause different types of malignancies and also main human disorder. Conspicuously, the epigenetic alteration special DNA methylation controls telomere length, telomerase activity and also function of different genes particularly hTERT expression. Telomeres are important in increasing the lifespan, health, aging, and the development and progression of some diseases like cancer.

METHODS

This review provides an assessment of the epigenetic alterations of telomeres, telomerase and repression of its catalytic subunit, hTERT and function of long non-coding RNAs such as telomeric-repeat containing RNA (TERRA) in carcinogenesis and tumorgenesis of gastric cancer.

RESULTS

hTERT expression is essential and indispensable in telomerase activation through immortality and malignancies and also plays an important role in maintaining telomere length. Telomeres and telomerase have been implicated in regulating epigenetic factors influencing certain gene expression. Correspondingly, these changes in the sub telomere and telomere regions are affected by the shortening of telomere length and increased telomerase activity and hTERT gene expression have been observed in many cancers, remarkably in gastric cancer.

CONCLUSION

Epigenetic alteration and regulation of hTERT gene expression are critical in controlling telomerase activity and its expression. Graphical Abstract.

Optimization of perioperative approaches for advanced and late stages of gastric cancer: clinical proposal based on literature evidence, personal experience, and ongoing trials and research

BACKGROUND

The high incidence of gastric cancer (GC) and paradoxical high prevalence of advanced stage GC, amounting to around 2/3 at time of diagnosis, have urged doctors and researchers around the world not only to ameliorate the detection rate of GC at early stages but also to optimize the clinical management of GC at advanced stages.

CONTENT

We hereby recommend a more goal-oriented multimodality approach with objectives to increase survival rate and improve survival status. Based on precision and accurate clinical staging at diagnosis, we suggest that advanced stage GC (AGC) patients should be channeled into different treatment plans according to their disease status where they can be subjected to comprehensive measures involving chemo, radio, immunological, or target therapies depending on the pathophysiological behavior of their tumor. Patients assessed as potentially resectable cT4N + M0 can undergo neoadjuvant chemotherapy with intent of tumor downsizing and downgrading followed by surgery with intraoperative hyperthermic intraperitoneal chemotherapy (HIPEC) to decrease the incidence of peritoneal dissemination due to surgical trauma and adjuvant chemotherapy and radiation in cases of bulky nodal metastasis. In cases with distal metastasis, conversion therapy is recommended with the possibility of surgery of curative intent in case of favorable response. The options of alternate treatment options such as trans-catheter arterial chemoembolization (TACE) for limited liver lesions or neoadjuvant intraperitoneal plus systemic chemotherapy (NIPS) for peritoneal carcinomatosis have to be negotiated. With surgery as the cornerstone for cancer treatment, there is acknowledgment of the significance of perioperative comprehensive approaches but there has not been some consensus guiding clinical application. Henceforth, in this review, based on past literature, current guidelines and ongoing clinical trials, we have shared a proposal of the current treatment modalities in practice for the advanced stages of gastric cancer.

CONCLUSION

Even though surgery is the golden standard of radical cancer treatment, clinical reality shows that without proper perioperative management, patients undergoing radical resections manifest high rates of recurrence and metastasis. Hence, in this review, we have outlined a clinical agenda to optimize the management of advanced stage GC with objective to improve survival outcome and quality of life of patients.

Long Non-Coding RNA TMPO-AS1 Promotes Cell Migration and Invasion by Sponging miR-140-5p and Inducing SOX4-Mediated EMT in Gastric Cancer

Background

Mounting evidence show that long non-coding RNAs (lncRNAs) play critical roles in the progression of various human cancers, including gastric cancer (GC), a common gastrointestinal tumor. In this study, the biological functions of lncRNA TMPO-AS1 in GC were studied.

Methods

TMPO-AS1 and miR-140-5p expression levels were detected in GC tissues and cell lines by RT-qPCR analysis. Knockdown or overexpression of TMPO-AS1 was conducted to evaluate the effects of TMPO-AS1 on the malignant behaviors of GC cells. Bioinformatic prediction and dual-luciferase reporter assay were performed to investigate the direct interaction between TMPO-AS1 and miR-140-5p in GC.

Results

We observed that TMPO-AS1 was up-regulated in GC tissues, and high TMPO-AS1 expression in GC patients was closely correlated with aggressive clinicopathologic characteristics and poor overall survival. Functionally, gain- and loss-of-function studies showed that TMPO-AS1 overexpression enhanced the proliferation, migration, invasion and EMT of GC cells in vitro, whereas knockdown of TMPO-AS1 inhibited these malignant traits. Importantly, we demonstrated that TMPO-AS1 could function as a competing endogenous RNA (ceRNA) by sponging miR-140-5p in GC cells, thereby diminishing the inhibition on SOX4, an EMT regulator.

Conclusion

Our findings indicated that TMPO-AS1 promotes GC progression partly by regulating miR-140-5p/SOX4 axis, and may serve as a novel therapeutic target for GC.

Multi-Modality Treatment for Patients With Metastatic Gastric Cancer: A Real-World Study in China

Introduction: People with metastatic gastric cancer (GC) have a poor prognosis. The study aims to investigate the efficacy of multi-modality treatment for patients with metastatic GC.

Methods: We retrospectively identified 267 patients with stage IV gastric cancer who were treated with systemic chemotherapy: 114 received multi-modality treatments, 153 received systematic chemotherapy alone. The survival of these two groups was compared by log rank test, the independent prognostic factors were investigated using univariate and multivariate analyses.

Results: The median survival of metastatic GC patients who received multi-modality treatment was significantly longer than those who received systematic chemotherapy alone (18.4 vs. 11.4 months, P < 0.001). Multivariate analysis identified tumor histologic differentiation, CA19–9 level, previous curative resection, palliative gastrectomy, and metastasectomy as independent prognostic factors for overall survival. In the multimodality treatment group, patients who received palliative gastrectomy or metastasectomy had a longer survival than those who only received intraperitoneal chemotherapy or radiotherapy (21.6 vs. 15.2 months, P = 0.014).

Conclusion: Multi-modality treatments offer a survival benefit for patients with metastatic GC. Future prospective studies are needed to confirm the result.

LDLRAD2 overexpression predicts poor prognosis and promotes metastasis by activating Wnt/β-catenin/EMT signaling cascade in gastric cancer

The therapeutic strategies for advanced gastric cancer (GC) remain unsatisfying and limited. Therefore, it is still imperative to fully elucidate the mechanisms underlying GC aggressive progression. The prognostic value and biological functions of low density lipoprotein receptor class A domain containing protein 2 (LDLRAD2) in GC have never been studied yet. We found that LDLRAD2 expression was significantly upregulated in GC and closely correlated with poor prognosis in GC patients. Functionally, LDLRAD2 promoted epithelial-mesenchymal transition, migration and invasion, and metastasis of GC cells. Mechanistically, LDLRAD2 interacted with and inhibited Axin1 from binding to cytoplasmic β-catenin, which facilitated the nuclear translocation of β-catenin, thereby activating Wnt/β-catenin pathway. Inhibition of β-catenin activity markedly abolished LDLRAD2-induced migration, invasion and metastasis. Together, these results suggested that LDLRAD2 contributed to invasion and metastasis of GC through activating Wnt/β-catenin pathway. LDLRAD2/ Wnt/β-catenin axis may be a potential therapeutic target for GC treatment.

Knockdown of ROS proto-oncogene 1 inhibits migration and invasion in gastric cancer cells by targeting the PI3K/Akt signaling pathway

Objectives

Gastric cancer ranks the fourth most common cancer and the third leading cause of cancer mortality in the world. ROS proto-oncogene 1 (ROS1) is an oncogene and ROS1 rearrangement has been reported in many cancers. Our study aimed to investigate the potential function and the precise mechanisms of ROS1 in gastric cancer.

Methods

In our study, the analysis of ROS1 expression and clinical pathologic factors of gastric cancer in gastric cancer using TCGA database demonstrated that ROS1 expression was elevated in gastric cancer and related to T, N, M and TNM staging. High expression of ROS1 predicted poor survival in patients with gastric cancer. Then, we measured ROS1 expression in four human gastric cancer cell lines and knocked down ROS1 expression in BGC-823 and SGC-7901 cells by specific shRNA transfection via Lipofectamine 2000. The effect of ROS1 knockdown on cell proliferation, cell cycle distribution, cell apoptosis and metastasis in vitro was evaluated by MTT, colony formation, flow cytometric analysis, wound healing and Transwell invasion assays. The levels of apoptosis-related proteins, EMT markers and the PI3K/Akt signaling pathway members were measured by Western blotting.

Results

We demonstrated that shROS1 transfection markedly downregulated ROS1 expression in BGC-823 and SGC-7901 cells. Knockdown of ROS1 inhibited cell survival, clonogenic growth, migration, invasion and epithelial–mesenchymal transition (EMT), as well as induced cell cycle arrest and apoptosis in gastric cancer cells. Furthermore, ROS1 knockdown inhibited the phosphorylation of PI3K and Akt.

Conclusion

Collectively, our data suggest that ROS1 may serve as a promising therapeutic target in gastric cancer treatment.

Identification of hsa_circ_0001821 as a Novel Diagnostic Biomarker in Gastric Cancer via Comprehensive Circular RNA Profiling

Background: The morbidity and mortality of gastric cancer (GC) remain high worldwide. With the advent of the Human Genome Sequencing Project, circular RNAs (circRNAs) have attracted widespread attention in cancer research due to their stable ring structure. Our aim was to identify differentially expressed circRNAs in GC and explore their potential roles in GC diagnosis, treatment, and prognostic prediction.

Methods: Large-scale gene screening was performed in three pairs of GC tissues and adjacent noncancerous tissues using high-throughput sequencing. The expression of hsa_circ_0001821 was detected in 80 pairs of tissue samples by quantitative real-time PCR (qRT-PCR). Stability of the ring structure of hsa_circ_0001821 RNA was verified by exonuclease digestion assay, and its diagnostic value was evaluated by receiver operating characteristic (ROC) analysis. In addition, the location of hsa_circ_0001821 in GC cells was detected by nucleoplasm separation assay.

Results: A total of 25,303 circRNAs were identified, among which 2,007 circRNAs were differentially expressed (fold change > 2.0, P < 0.05). Further validation disclosed that hsa_circ_0001821 was significantly downregulated in the 80 pairs of GC tissues and 30 whole-blood specimens obtained from the GC patients. The specificity of hsa_circ_0001821 in GC was higher than that in other solid tumors. In addition, hsa_circ_0001821 was relatively stable after RNA exonuclease digestion. Clinicopathological parameter analysis showed that hsa_circ_0001821 was negatively correlated with tumor depth (r = −0.255, P = 0.022) and lymph node metastasis (r = −0.235, P = 0.036). Area under the curve (AUC) analysis showed that the diagnostic efficiency of circulating hsa_circ_0001821 in distinguishing GC patients was higher than that in GC tissues (0.872, 95%CI: 0.767–0.977 vs. 0.792, 95%CI: 0.723–0.861). Combined use of circulating hsa_circ_0001821 with the existing tumor markers yielded the largest AUC of 0.933. Finally, hsa_circ_0001821 was demonstrated to mainly locate in the cytoplasm, implying that it played a potential regulatory role in GC at the posttranscriptional level.

Conclusion: Hsa_circ_0001821 may prove to be a new and promising potential biomarker for GC diagnosis.

Clinicopathologic and Prognostic Significance of Thymopoietin-α Overexpression in Gastric Cancer

As one of the deadliest and most common malignancies in the world, gastric cancer (GC) represents a serious health threat. Despite recent advances in the field, the prognosis of patients with metastatic GC remains poor. In this study, we aimed to investigate the clinical impact of the alpha subunit of the nuclear structural protein thymopoietin (TMPO-α) in GC. The expression of TMPO-α in seven gastric cell lines was detected by immunoblotting. The expression level of TMPO-α levels in gastric tissues collected from 145 GC patients was examined by immunohistochemistry. The correlations between TMPO-α expression level and clinicopathologic parameters, as well as the association of TMPO-α expression with overall survival, were assessed. Immunohistochemistry showed that the expression of TMPO-α was significantly higher in GC tissues and cells in comparison with non-tumor tissues and cells. Furthermore, the overexpression of TMPO-α in gastric tissues (56%) was positively associated with Lauren classification (P = 0.0159), nodal status (P = 0.0265), distant metastasis (P < 0.0001), stage (P = 0.0367), and degree of differentiation (P = 0.0009). Patients with high TMPO-α levels had a significantly poorer overall survival than those with low levels (P = 0.001). Multivariate Cox regression analysis also indicated that TMPO-α was an independent prognostic marker for GC (P = 0.045). In addition, studies conducted in GC cells indicated that knockdown of TMPO-α suppressed cell proliferation and invasion. These findings indicate that TMPO-α overexpression can predict clinicopathologic features and the outcome of patients with GC.

Impaired autophagic degradation of lncRNA ARHGAP5-AS1 promotes chemoresistance in gastric cancer

Chemoresistance remains the uppermost disincentive for cancer treatment on account of many genetic and epigenetic alterations. Long non-coding RNAs (lncRNAs) are emerging players in promoting cancer initiation and progression. However, the regulation and function in chemoresistance are largely unknown. Herein, we identified ARHGAP5-AS1 as a lncRNA upregulated in chemoresistant gastric cancer cells and its knockdown reversed chemoresistance. Meanwhile, high ARHGAP5-AS1 expression was associated with poor prognosis of gastric cancer patients. Intriguingly, its abundance is affected by autophagy and SQSTM1 is responsible for transporting ARHGAP5-AS1 to autophagosomes. Inhibition of autophagy in chemoresistant cells, thus, resulted in the upregulation of ARHGAP5-AS1. In turn, it activated the transcription of ARHGAP5 in the nucleus by directly interacting with ARHGAP5 promoter. Interestingly, ARHGAP5-AS1 also stabilized ARHGAP5 mRNA in the cytoplasm by recruiting METTL3 to stimulate m⁶A modification of ARHGAP5 mRNA. As a result, ARHGAP5 was upregulated to promote chemoresistance and its upregulation was also associated with poor prognosis in gastric cancer. In summary, impaired autophagic degradation of lncRNA ARHGAP5-AS1 in chemoresistant cancer cells promoted chemoresistance. It can activate the transcription of ARHGAP5 in the nucleus and stimulate m⁶A modification of ARHGAP5 mRNA to stabilize ARHGAP5 mRNA in the cytoplasm by recruiting METTL3. Therefore, targeting ARHGAP5-AS1/ARHGAP5 axis might be a promising strategy to overcome chemoresistance in gastric cancer.

Hyaluronan-mediated motility receptor confers resistance to chemotherapy via TGFβ/Smad2-induced epithelial-mesenchymal transition in gastric cancer

Chemotherapy is one of the vital treatments for gastric cancer (GC) patients, especially those suffering advanced stages. Chemoresistance results in tumor relapse, leading to poor prognosis in GC patients; thus, identifying key regulators in this process might provide novel clues for GC therapy. Herein, we identify hyaluronan-mediated motility receptor (HMMR) as a key regulator of chemoresistance in GC. HMMR was found to be substantially up-regulated in 5-fluorouracil (5-Fu)-resistant GC biopsies and cell lines. High expression of HMMR significantly correlates with tumor relapse and predicts poorer prognosis in GC patients. Moreover, we observed that HMMR induced epithelial-mesenchymal transition and increased the cancer stem cell properties of GC, thus rendering resistance to chemotherapy. Importantly, silencing of HMMR effectively increased the susceptibility to 5-Fu therapy both in vitro and in vivo. Furthermore, we demonstrated that HMMR activates the TGF-β/Smad2 signaling pathway, which was required for the HMMR-mediated oncogenic effects and exhibited significant clinical relevance with HMMR expression. These findings reveal a critical role for HMMR in the chemoresistance of GC and suggest that HMMR might be a potential prognostic marker or therapeutic target against the disease.-Zhang, H., Ren, L., Ding, Y., Li, F., Chen, X., Ouyang, Y., Zhang, Y., Zhang, D. Hyaluronan-mediated motility receptor confers resistance to chemotherapy via TGFβ/Smad2-induced epithelial-mesenchymal transition in gastric cancer.

Low expression of CD80 predicts for poor prognosis in patients with gastric adenocarcinoma

AIM

To study the expression and prognostic significance of CD80 in patients with gastric adenocarcinoma. Materials & methods: Real-time quantitative PCR, western blot and immunohistochemistry were performed to detect the expression of CD80 in gastric cancer tissues and matched adjacent normal tissues. Double immunohistochemical staining was performed to preliminary examine the relationship between CD80⁺ cells and CD8⁺ cytotoxic T lymphocytes.

RESULTS

The expression of CD80 was downregulated in tumor tissues compared with normal tissues (p = 0.002). Immunohistochemistry analysis showed that 49 (39.8%) of 123 patients with gastric cancer demonstrated reduced CD80 expression, which was correlated with the tumor differentiation grade.

CONCLUSION

Our data suggest that reduced CD80 expression independently predicts a poor prognosis in patients with gastric adenocarcinoma.

A region-resolved mucosa proteome of the human stomach

The human gastric mucosa is the most active layer of the stomach wall, involved in food digestion, metabolic processes and gastric carcinogenesis. Anatomically, the human stomach is divided into seven regions, but the protein basis for cellular specialization is not well understood. Here we present a global analysis of protein profiles of 82 apparently normal mucosa samples obtained from living individuals by endoscopic stomach biopsy. We identify 6,258 high-confidence proteins and estimate the ranges of protein expression in the seven stomach regions, presenting a region-resolved proteome reference map of the near normal, human stomach. Furthermore, we measure mucosa protein profiles of tumor and tumor nearby tissues (TNT) from 58 gastric cancer patients, enabling comparisons between tumor, TNT, and normal tissue. These datasets provide a rich resource for the gastrointestinal tract research community to investigate the molecular basis for region-specific functions in mucosa physiology and pathology including gastric cancer.

The human stomach is divided into seven anatomically distinct regions but their protein composition is largely unknown. Here, the authors present a region-resolved map of the healthy human stomach mucosa as well as mucosa proteomes of tumor and tumor nearby tissue from gastric cancer patients.

Identification of molecular biomarkers for the diagnosis of gastric cancer and lymph-node metastasis

Background and objective

Biomarkers are important tools for prompt diagnosis of cancer. This study aimed to identify reliable biomarkers for clinical applications in the diagnosis of gastric cancer and lymph-node (LN) metastasis.

Methods

Between 1 December 2014 and 31 December 2015, we prospectively collected samples of gastric-cancer tissues, corresponding matched-pair normal gastric mucosa, and their peri-gastric metastatic and non-metastatic LNs to identify quantitatively reliable genes using quantitative real-time polymerase chain reaction. Relative quantity (RQ) was used to calculate the mRNA expression levels of our target genes. Statistics were calculated using one-way analysis of variance (ANOVA) and Tukey’s multiple comparison test. Analytical graphs were plotted using GraphPad Prism.

Results

Of nine assessed genes, the mRNA levels of inhibin beta A (INHBA) and secreted phosphoprotein 1 (SPP1) were most consistently highly expressed in tumor tissues by 15.4- and 15.6-fold, respectively, as compared with normal tissues (P < 0.001), with 91.3% sensitivity and 95.7% specificity (receiver operating characteristic [ROC] curve area = 0.974) for the former and 82.6% sensitivity and 87.0% specificity (ROC curve area = 0.924) for the latter. Further analysis revealed no differentiating significance of SPP1 mRNA expression between metastatic and non-metastatic LNs (P = 0.470). In contrast, the INHBA mRNA level was up-regulated 4.1-fold in metastatic LNs (P < 0.001), with 80.0% sensitivity and 81.5% specificity (ROC curve area = 0.857), and was also able to successfully differentiate between more severe disease conditions, T3 and T4 (P = 0.003), M0 and M1 (P = 0.043) and different histological variants (intestinal type vs diffuse type, P = 0.019).

Conclusions

Our results showed that INHBA was the most optimally reliable biomarker for diagnosing gastric cancer and LN metastasis.

DDIT4 promotes gastric cancer proliferation and tumorigenesis through the p53 and MAPK pathways

Background

Gastric cancer (GC) is one of the most common malignancies worldwide, particularly in China. DNA damage-inducible transcript 4 (DDIT4) is a mammalian target of rapamycin inhibitor and is induced by various cellular stresses; however, its critical role in GC remains poorly understood. The present study aimed to investigate the potential relationship and the underlying mechanism between DDIT4 and GC development.

Methods

We used western blotting, real-time polymerase chain reaction, and immunohistochemical or immunofluorescence to determine DDIT4 expression in GC cells and tissues. High-content screening, cell counting kit-8 assays, colony formation, and in vivo tumorigenesis assays were performed to evaluate cell proliferation. Flow cytometry was used to investigate cell apoptosis and cell cycle distribution.

Results

DDIT4 was upregulated in GC cells and tissue. Furthermore, downregulating DDIT4 in GC cells inhibited proliferation both in vitro and in vivo and increased 5-fluorouracil-induced apoptosis and cell cycle arrest. In contrast, ectopic expression of DDIT4 in normal gastric epithelial cells promoted proliferation and attenuated chemosensitivity. Further analysis indicated that the mitogen-activated protein kinase and p53 signaling pathways were involved in the suppression of proliferation, and increased chemosensitivity upon DDIT4 downregulation.

Conclusion

DDIT4 promotes GC proliferation and tumorigenesis, providing new insights into the role of DDIT4 in the tumorigenesis of human GC.

Electronic supplementary material

The online version of this article (10.1186/s40880-018-0315-y) contains supplementary material, which is available to authorized users.

Gastric cancer vaccines synthesized using a TLR7 agonist and their synergistic antitumor effects with 5-fluorouracil

Background

Vaccines play increasingly important roles in cancer treatment due to their advantages of effective targeting and few side effects. Our laboratory has attempted to construct vaccines by conjugating TLR7 agonists with tumor-associated antigens. Furthermore, immunochemotherapy has recently become an appealing approach to cancer therapy. 5-fluorouracil (5-FU), a commonly used chemotherapeutic agent, can reportedly potently and selectively kill tumor-associated MDSCs in vivo.

Methods

Gastric cancer vaccines were synthesized by the covalent attachment of our TLR7 agonist with the gastric cancer antigen MG7-Ag tetra-epitope, leading to T7 − ML (linear tetra-epitope) and T7 − MB (branched tetra-epitope). Cytokines induced by the vaccines in vitro were assessed by ELISA. A tumor challenge model was created by treating BALB/c mice on either a prophylactic or therapeutic vaccination schedule. 5-FU was simultaneously applied to mice in the combination treatment group. CTL and ADCC activities were determined by the LDH method, while CD3⁺/CD8⁺, CD3⁺/CD4⁺ T cells and MDSCs were evaluated by flow cytometry.

Results

In vitro, rapid TNF-α and IL-12 inductions occurred in BMDCs treated with the vaccines. In vivo, among all the vaccines tested, T7 − MB most effectively reduced EAC tumor burdens and induced CTLs, antibodies and ADCC activity in BALB/c mice. Immunization with T7 − MB in combination with 5-FU chemotherapy reduced tumor sizes and extended long-term survival rates, mainly by improving T cell responses, including CTLs, CD3⁺/CD8⁺ and CD3⁺/CD4⁺ T cells. 5-FU also enhanced the T7 − MB efficiency by reversing immunosuppressive factors, i.e., MDSCs, which could not be validly inhibited by the vaccines alone. In addition, T7 − MB repressed tumor growth and immune tolerance when the therapeutic schedule was used, although the effects were weaker than those achieved with either T7 − MB alone or in combination with 5-FU on the prophylactic schedule.

Conclusions

A novel effective gastric cancer vaccine was constructed, and the importance of branched multiple antigen peptides and chemical conjugation to vaccine design were confirmed. The synergistic effects and mechanisms of T7 − MB and 5-FU were also established, observing mainly T cell activation and MDSC inhibition.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1501-z) contains supplementary material, which is available to authorized users.

Network Pharmacology-Based Approach to Investigate the Mechanisms of Hedyotis diffusa Willd. in the Treatment of Gastric Cancer

BACKGROUND

Hedyotis diffusa Willd. (HDW) is one of the renowned herbs often used in the treatment of gastric cancer (GC). However, its curative mechanism has not been fully elucidated.

OBJECTIVE

To systematically investigate the mechanisms of HDW in GC.

METHODS

A network pharmacology approach mainly comprising target prediction, network construction, and module analysis was adopted in this study.

RESULTS

A total of 353 targets of the 32 bioactive compounds in HDW were obtained. The network analysis showed that CA isoenzymes, p53, PIK3CA, CDK2, P27Kip1, cyclin D1, cyclin B1, cyclin A2, AKT1, BCL2, MAPK1, and VEGFA were identified as key targets of HDW in the treatment of GC. The functional enrichment analysis indicated that HDW probably produced the therapeutic effects against GC by synergistically regulating many biological pathways, such as nucleotide excision repair, apoptosis, cell cycle, PI3K/AKT/mTOR signaling pathway, VEGF signaling pathway, and Ras signaling pathway.

CONCLUSIONS

This study holistically illuminates the fact that the pharmacological mechanisms of HDW in GC might be strongly associated with its synergic modulation of apoptosis, cell cycle, differentiation, proliferation, migration, invasion, and angiogenesis.

Selective survival advantage associated with primary tumor resection for metastatic gastric cancer in a Western population

BACKGROUND

The prognosis of metastatic gastric cancer (GC) remains dismal, with a median survival of 10 months. Historically, primary tumor resection was not thought to confer any survival benefit. Although high-level data exist guiding treatment of metastatic GC for patients in the East, no such data exist for Western patients despite inherent ethnic differences in GC biology.

METHODS

The 2006-2012 National Cancer Database was queried for adult patients with metastatic gastric adenocarcinoma. Patients were classified into those who underwent primary tumor resection and chemotherapy (PTRaC) and those who received chemotherapy only. Groups were propensity score matched, and survival was compared using advanced statistical modeling.

RESULTS

A total of 7026 patients met the inclusion criteria: 6129 (87%) patients were treated with chemotherapy alone and 897 (13%) patients were treated with PTRaC. After multivariable adjustment, patients who underwent PTRaC had a significantly better overall survival (OS) than patients who received systemic therapy only (HR, 0.60; 95% CI, 0.56-0.64; p < 0.001). Following full bipartite propensity score-adjusted analysis, 2-year OS for patients who received chemotherapy only was 12.6% (95% CI, 11.7-13.5%), whereas it was 34.2% (95% CI, 31.3-37.5%) for patients who underwent PTRaC (HR for resection: 0.52; 95% CI, 0.47-0.57; p < 0.001).

CONCLUSION

Our data suggest that there exists a subset of patients with metastatic GC for which PTRaC may improve OS. As significant uncertainty still remains, our results support the need for further prospective trials investigating the influence of palliative gastrectomy on survival among Western patients.

Impact of preoperative anemia on outcomes in patients undergoing curative resection for gastric cancer: a single-institution retrospective analysis of 2163 Chinese patients

We sought to evaluate whether preoperative anemia was an important determinant of survival in gastric cancer (GC). A single institution cohort of 2163 GC patients who underwent curative resection were retrospectively analyzed. Anemia was defined as a preoperative hemoglobin level <120 g/L in males and <110 g/L in females. Overall survival (OS) was analyzed using the Kaplan-Meier method, and a multivariate Cox proportional hazards model was performed to identify the independent prognostic factor. Anemic patients had a poorer OS compared with nonanemic patients after resection for tumor-nodes-metastasis (TNM) stage III tumors (5-year OS rate: 32.2% vs. 45.7%, P < 0.001) but not stage I (P  =  0.480) or stage II (P  =  0.917) tumors. Multivariate analysis revealed that preoperative anemia was an independent prognostic factor in TNM stage III (hazard ratio [HR], 1.771; 95% CI, 1.040-3.015; P = 0.035). In a stage-stratified analysis, preoperative anemia was still independently associated with OS in TNM stages IIIa through IIIc (P < 0.001, P = 0.075, and P = 0.012, respectively), though the association was only marginal in stage IIIb. Of note, preoperative mild anemia had a similar prognostic value in TNM stage III GC. Furthermore, preoperative anemia was significantly associated with more perioperative transfusions, postoperative complications and several nutritional-based indices, including the prognostic nutritional index (PNI), preoperative weight loss and performance status (all P < 0.05). Preoperative anemia, even mild anemia, was an important predictor of postoperative survival for TNM stage III GC.

Low Expression of CDK10 Correlates with Adverse Prognosis in Gastric Carcinoma

Background: Cyclin-dependent kinase (CDK) 10, is reported to play an essential role in the progression from the G2 to M phase of the cell cycle. Recently, reduced expression of CDK10 has been observed in several cancerous human tissue, suggesting that CDK10 is a tumor suppressor gene. However, data on its expression pattern and clinical relevance in gastric cancer are not sufficient. Therefore, this study aims to investigate CDK10 expression and its prognostic significance in primary gastric adenocarcinoma.

Methodology/Principal Findings: The expression level of CDK10 was analyzed using qRT-PCR, western blotting, and immunohistochemistry on tissue samples from 189 post-resection gastric cancer patients. The expression of CDK10 mRNA was reduced in tumor tissue samples compared with matched adjacent non-tumor tissue samples (P=0.013); this finding was confirmed by western blot analysis (P=0.016). Immunohistochemistry data indicated that CDK10 expression was significantly decreased in 92 of 189 (48.7%) gastric cancer cases. Kaplan-Meier survival curves revealed that decreased expression of CDK10 was strongly associated with a poor prognosis in gastric cancer patients (P<0.001). Multivariate Cox analysis identified CDK10 expression as an independent prognostic factor for overall survival (P=0.011).

Conclusions/Significance: Our data suggest that reduced CDK10 expression independently predicts a poor prognosis in patients with gastric cancer. CDK10 can may serve as a valuable prognostic marker and a potential target for gene therapy.

The long noncoding RNA, TINCR, functions as a competing endogenous RNA to regulate PDK1 expression by sponging miR-375 in gastric cancer

BACKGROUND

Accumulating evidence indicates that the long noncoding RNA, TINCR, plays a critical role in cancer progression and metastasis. However, the overall biological role and mechanisms of TINCR that were involved in human gastric cancer (GC) progression remain largely unknown.

METHODS

TINCR expression was measured in 56 paired tumor and adjacent nontumor tissue samples by real-time polymerase chain reaction (PCR). Insights of the mechanism of competitive endogenous RNAs (ceRNAs) were gained from bioinformatic analysis, luciferase assays. The effects of TINCR and miR-375 on GC cell apoptosis and proliferation were studied by RNA interference approaches in vitro and in vivo. The correlation of TINCR and PDK1 was identified by real-time PCR and Western blot analysis.

RESULTS

Our results showed that miR-375 level decreased and TINCR level increased in tumor tissues. In addition, TINCR was a target of miR-375 and inhibited its expression in GC cells. Furthermore, the low expression of TINCR increased cell apoptosis and inhibited the proliferation of GC cells, while the downregulation of miR-375 reversed the function. In particular, TINCR could negatively regulate the miR-375 expression and increased the PDK1 expression in GC cells. Finally, tumor growth suppression was retarded with miR-375 downregulated in TINCR knockdown of GC cell xenografts.

CONCLUSION

The long noncoding RNA TINCR functions as a competing endogenous RNA to regulate PDK1 expression by sponging miR-375 in GC. The ceRNA regulatory network of TINCR/miR-375/PDK1 allows us to better understand the pathogenesis of GC and facilitate the development of long noncoding RNA (lncRNA)-directed diagnostics in GC.

Efficacy and safety comparison of chemotherapies for advanced gastric cancer: A network meta-analysis

OBJECTIVE

Chemotherapy is one of the commonly used therapies for advanced gastric cancer. In this study, we performed a network meta-analysis on the efficacy and safety of common treatments to give evidences of their relative benefits.

RESULTS

32 trials with 8550 patients and 20 regimens were included in this study. According to the results of primary outcomes, 5-FU plus OXA, 5-FU plus DOC, CAP plus CIS, CAP plus OXA, S-1 plus OXA and S-1 plus PAC performed well in improving OS and ORR. As for the adverse events, S-1 had a safer effect than other treatments, conversely, 5-FU plus CIS ranked the last. However, there was no regimen with outstanding performances in both efficacy and safety.

MATERIALS AND METHODS

Studies were searched from database and screened with criteria. The Bayesian framework based network meta-analysis was performed with software R and STATA. Overall survival (OS) and overall response rate (ORR) were considered as primary outcomes while adverse events as secondary outcomes. The outcomes were represented by hazard ratios or odd ratios with 95% corresponding credible intervals, respectively.

CONCLUSIONS

The network meta-analysis suggested that 5-FU plus OXA and 5-FU plus DOC were recommended when efficacy was stressed. S-1 was safest but poorly effective. A regimen, as an excellent combination of efficacy and safety, is still waiting to be discovered.

The Relationship between RUNX3 Expression, Nursing Strategies and Nutritional Status in Elderly Patients with Advanced Gastric Cancer

BACKGROUND

The aim of this study was to explore the relationship between nutritional status and expression of RUNX3 in gastric cancer cells and to investigate the effects of nursing strategies on the nutritional status of elderly patients with advanced gastric cancer.

METHODS

Forty-eight elderly patients admitted at Affiliated Hospital of Qingdao University with advanced gastric cancer and 30 healthy controls were selected as subjects from 2014-15. The correlation between RNX3 gene expression and nutritional status of the gastric cancer patients was investigated. The patients with advanced gastric cancer who had low expression of RUNX3 gene were treated with holistic nursing while routine nursing was taken for those patients who had normal or high expression of RUNX3 gene. The nutritional statuses of these patients were evaluated after 3 months of nursing. After a follow-up of 1 year, the influence of different nursing methods on the survival time was evaluated.

RESULTS

Compared with normal gastric tissue, the expression of RUNX3 gene and protein in tissues of advanced gastric cancer were significantly decreased (P<0.01). Compared with patients with normal or high expressions of RUNX3, the nutritional statuses of advanced gastric cancer patients with low expressions of RUNX3 were lower (P<0.01). The nutritional statuses of patients with low expressions of RUNX3 were notably improved after holistic nursing, becoming equivalent to those with normal or high expression of RUNX3 who received routine nursing (P>0.05). The survival time of patients with low expression of RUNX3 who received holistic nursing were similar to patients with normal or high expression of RUNX3 who received routine nursing (P>0.05).

CONCLUSION

RUNX3 is correlated with the occurrence and development of advanced gastric cancer. The low nutritional status of elderly advanced gastric cancer patients with low expressions of RUNX3 can be significantly enhanced by holistic nursing, thereby prolonging survival time.

NF-κB Signaling in Gastric Cancer

Gastric cancer is a leading cause of cancer death worldwide. Diet, obesity, smoking and chronic infections, especially with Helicobacter pylori, contribute to stomach cancer development. H. pylori possesses a variety of virulence factors including encoded factors from the cytotoxin-associated gene pathogenicity island (cagPAI) or vacuolating cytotoxin A (VacA). Most of the cagPAI-encoded products form a type 4 secretion system (T4SS), a pilus-like macromolecular transporter, which translocates CagA into the cytoplasm of the host cell. Only H. pylori strains carrying the cagPAI induce the transcription factor NF-κB, but CagA and VacA are dispensable for direct NF-κB activation. NF-κB-driven gene products include cytokines/chemokines, growth factors, anti-apoptotic factors, angiogenesis regulators and metalloproteinases. Many of the genes transcribed by NF-κB promote gastric carcinogenesis. Since it has been shown that chemotherapy-caused cellular stress could elicit activation of the survival factor NF-κB, which leads to acquisition of chemoresistance, the NF-κB system is recommended for therapeutic targeting. Research is motivated for further search of predisposing conditions, diagnostic markers and efficient drugs to improve significantly the overall survival of patients. In this review, we provide an overview about mechanisms and consequences of NF-κB activation in gastric mucosa in order to understand the role of NF-κB in gastric carcinogenesis.

The long noncoding RNA PVT1 functions as a competing endogenous RNA by sponging miR-186 in gastric cancer

BACKGROUND

Recent evidence has highlighted the key regulatory roles of long non-coding RNAs (lncRNAs) in tumor development and progression including gastric cancer (GC).The long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) has been identified as an oncogene in some tumors. However, the potential biological roles and regulatory mechanisms of PVT1 involved in GC remained poorly understood.

METHODS

Quantitative real-time PCR (QRT-PCR) was used to determine the expression of PVT1 and miR-186 in GC tissues. The MTT cell proliferation and transwell invasion assays were used to detect the cell proliferation and invasion abilities. Western-blotting analysis was used to detect the protein expression of PCNA and HIF-1α. To understand the tumorigenic mechanism of PVT1, luciferase reporter assays were performed to evaluate whether the miR-186 was a target of PVT1 in GC cells.

RESULTS

In the current study, we showed that PVT1 expression was markedly upregulated in GC tissues and cell lines, and high expression levels of PVT1 were obviously correlated with advanced tumor stage and lymph node metastasis. Further functional experiments indicated up-regulation of PVT1 promoted the GC cell proliferation and invasion, while down-regulation of PVT1 inhibited cell proliferation and invasion. In addition, PVT1 could directly interact with miR-186 in GC cells and this interaction lead to the inhibition of downstream of HIF-1α expression.

CONCLUSIONS

These results suggested that PVT1 acted as a key role in GC pathogenesis and may serve as a potential therapeutic target for GC.

The journey of personalizing gastric cancer treatment

Gastric cancer ranks the fourth most prevalent malignancy yet it is the second leading cause of cancer-related death. Every year, gastric cancer adds nearly 1 million new cancer cases, and 723,000 or 10% of cancer deaths to the global cancer burden. Approximately, 405,000 or 43% of the new cases and 325,000 or 45% of the deaths are in China, making gastric cancer a particularly challenging malignancy. This thematic series discusses the molecular classifications of gastric cancer by the Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG) as well as the implications in personalized therapeutic choices; discusses the evolution of gastric surgery and presents perspectives on surgical techniques in treating gastric cancer; and reviews current and emerging targeted agents as well as immunotherapies in treating gastric cancer. With these advancements in molecular characterization, surgical intervention, and targeted and immunotherapies, gastric cancer will enter a personalized medicine era in the next 5 years.