STUDY OF LOSS OF HETEROZYGOSITY AT DCC AND APC/MCC GENETIC LOCI OF GASTRIC CANCER

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EFFECT OF VL AND VH CONSENSUS SEQUENCE SPECIFIC PRIMERS ON THE BINDING AND EXPRESSION OF A MINI MOLECULE ANTIBODY DIRECTED TOWARDS HUMAN GASTRIC CANCER

To construct ScFv and Fab from murine anti gastric cancer monoclonal antibody(mAb)3H11. Methods.At first,3H11 ScFv and Fab were constructed with V genes PCR amplified by degenerate primers for FR1.The bacterial expressed 3H11 Ab fragments showed no antigen binding activity.Then,phage antibody library and random mutated library were constructed from 3H11 hybridoma cells and panning selection was performed.Again the identification of positive clone was failed.Finally the N terminal sequences of V regions were resumed to 3H11 original sequences by site directed mutagenesis via PCR. Results.Binding activity to gastric cancer cells was detected only from N terminal sequence corrected 3H11 ScFv and Fab,though the expression of the Ab fragments was not affected.Correction of either VL or VH N terminal sequences could partially resume the antigen binding activity. Conclusion.Sequence changes of V region N terminal introduced by PCR may seriously affect antigen binding without affecting the expression of antibody.

ANTIGEN MG7 IN GASTRIC CANCER AND GASTRIC PRECANCEROUS LESIONS

Objective: To study the dynamic change and its diagnostic significance of MG7 expression in the process of gastric cancer development. Methods: The expression level of antigen MG7 was determined by immunohistochemistry method in 406 cases of gastric mucosa. The classification of intestinal metaplasia of gastric mucosa was determined by histochemistry method in 82 cases. Results: The positive rate of MG7 expression in normal gastric mucosa, intestinal metaplasia and dysplasia of gastric mucosa and gastric cancer were increased gradually (P<0.01). The positive rate of MG7 expression in superficial gastritis, atrophic gastritis and gastric cancer were increased on sequence (P<0.01). The positive rate of antigen MG7 expression in type III intestinal metaplasia of gastric mucosa had significant difference, compared with that in type I an II intestinal metaplasia (P<0.05). Conclusion: MG7 antigen had close relationship with gastric cancer. Type III intestinal metaplasia, atrophic gastritis and dysplasia should be followed up in order to improve the early detection of gastric cancer. MG7 antigen had great clinical value in the dynamic follow-up of gastric precursors.

Diagnoses of gastric cancer and other gastric diseases by serum pepsinogen I and Ⅱ levels

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Pylorus-preserving gastrectomy for early gastric cancer

Pylorus-preserving gastrectomy(PPG)has been widely accepted as a function-preserving gastrectomy for middle-third early gastric cancer(EGC)with a distal tumor border at least 4 cm proximal to the pylorus.The procedure essentially preserves the function of the pyloric sphincter,which requires to preserve the upper third of the stomach and a pyloric cuff at least 2.5 cm.The suprapyloric and infrapyloric vessels are usually preserved,as are the hepatic and pyloric branches of the vagus nerve.Compared with distal gastrectomy,PPG has significant advantages in preventing dumping syndrome,body weight loss and bile reflux gastritis.The postoperative complications after PPG have reached an acceptable level.PPG can be considered a safe,effective,and superior choice in EGC,and is expected to be extensively performed in the future.

Double role of depression in gastric cancer:As a causative factor and as consequence

In this editorial we comment on the article“Hotspots and frontiers of the rela-tionship between gastric cancer and depression:A bibliometric study”.Gastric cancer(GC)is a common malignancy in the digestive system with increased mortality and morbidity rates globally.Standard treatments,such as gastrectomy,negatively impact patients'quality of life and beyond the physical strain,GC patients face psychological challenges,including anxiety and depression.The prevalence of depression can be as high as 57%,among gastrointestinal cancer patients.Due to the advancements in treatment effectiveness and increased 5-year overall survival rates,attention has shifted to managing psychological effects.However,the significance of managing the depression doesn’t lie solely in the need for a better psychological status.Depression leads to chronic stress acti-vating the sympathetic nervous system and the hypothalamus-pituitary-adrenal axis,leading release of catecholamines inducing tumor proliferation,migration,and metastasis,contributing to GC progression.The dysregulation of neurotrans-mitters and the involvement of various signaling pathways underscore the complex interplay between depression and GC.Comprehensive strategies are required to address the psychological aspects of GC,including region-specific interventions and increased monitoring for depression.Understanding the intricate relationship between depression and GC progression is essential for developing effective therapeutic strategies and improving overall outcomes for patients facing this complex disease.In this Editorial we delve into double role of depression in the pathogenesis of GC and as a complication of it.

Advances in MET tyrosine kinase inhibitors in gastric cancer

Gastric cancer is among the most frequently occurring cancers and a leading cause of cancer-related deaths globally.Because gastric cancer is highly heterogenous and comprised of different subtypes with distinct molecular and clinical characteristics,the management of gastric cancer calls for better-defined,biomarker-guided,molecular-based treatment strategies.MET is a receptor tyrosine kinase mediating important physiologic processes,such as embryogenesis,tissue regeneration,and wound healing.However,mounting evidence suggests that aberrant MET pathway activation contributes to tumour proliferation and metastasis in multiple cancer types,including gastric cancer,and is associated with poor patient outcomes.As such,MET-targeting therapies are being actively developed and promising progress has been demonstrated,especially with MET tyrosine kinase inhibitors.This review aims to briefly introduce the role of MET alterations in gastric cancer and summarize in detail the current progress of MET tyrosine kinase inhibitors in this disease area with a focus on savolitinib,tepotinib,capmatinib,and crizotinib.Building on current knowledge,this review further discusses existing challenges in MET alterations testing,possible resistance mechanisms to MET inhibitors,and future directions of MET-targeting therapies.

Ellagic acid inhibits gastric cancer cells by modulating oxidative stress and inducing apoptosis

Objective:To evaluate the anticancer effect of ellagic acid on gastric cancer cells.Methods:MTT assay was used to evaluate the effect of ellagic acid at different concentrations(0.5-100μg/mL)on gastric cancer AGS cells.RT-qPCR and Western blot analyses were applied to assess apoptosis(BCL-2,CASP-3,and BAX)and autophagy(LC3,ATG5,and BECN1)in AGS cells treated with ellagic acid.The expression of invasion-related markers including TP53,CDKN2A,and PTEN was determined.In addition,cell cycle markers including cyclin A,B,D,and E were measured by ELISA.Oxidative stress markers were evaluated using spectrophotometry.Results:Ellagic acid inhibited the proliferation of AGS cells in a concentration-and time-dependent manner.The expression of BCL-2 was significantly decreased(P<0.05)and CASP-3 and BAX were markedly increased(P<0.01)in AGS cells treated with ellagic acid.However,this compound induced no significant changes in the expression levels of LC3,ATG5,and BECN1(P>0.05).Moreover,the oxidative stress markers including SOD,TAC,and MDA were increased by ellagic acid(P<0.01).Conclusions:Ellagic acid can inhibit cell proliferation,induce apoptosis,and modulate oxidative stress in AGS cells.However,further in vivo and molecular studies are needed to verify its anticancer efficacy.

Development and validation of a prognostic immunoinflammatory index for patients with gastric cancer

BACKGROUND Studies have demonstrated the influence of immunity and inflammation on the development of tumors.Although single biomarkers of immunity and inflam-mation have been shown to be clinically predictive,the use of biomarkers integrating both to predict prognosis in patients with gastric cancer remains to be investigated.AIM To investigate the prognostic and clinical significance of inflammatory biomarkers and lymphocytes in patients undergoing surgical treatment for gastric cancer.METHODS Univariate COX regression analysis was performed to identify potential prognostic factors for patients with gastric cancer undergoing surgical treatment.Least absolute shrinkage and selection operator-COX(LASSO-COX)regression analysis was performed to integrate these factors and formulate a new prognostic immunoinflammatory index(PII).The correlation between PII and clinical charac-teristics was statistically analyzed.Nomograms incorporating the PII score were devised and validated based on the time-dependent area under the curve and decision curve analysis.RESULTS Patients exhibiting elevated neutrophil-to-lymphocyte ratio,platelet-to-lymphocyte ratio,and systemic immune inflammatory index displayed inferior progression-free survival(PFS)and overall survival(OS).Conversely,low levels of CD3(+),CD3(+)CD8(+),CD4(+)CD8(+),and CD3(+)CD16(+)CD56(+)T lymphocytes were associated with improved PFS and OS,while high CD19(+)T lymphocyte levels were linked to worse PFS and OS.The PII score demonstrated associations with tumor characteristics(primary tumor site and tumor size),establishing itself as an independent prognostic factor for both PFS and OS.Time-dependent area under the curve and decision curve analysis affirmed the effectiveness of the PII-based nomogram as a robust prognostic predictive model.CONCLUSION PII may be a reliable predictor of prognosis in patients with gastric cancer undergoing surgical treatment,and it offers insights into cancer-related immune-inflammatory responses,with potential significance in clinical practice.

Immunotherapy of gastric cancer:Present status and future perspectives

In this editorial,we comment on the article entitled“Advances and key focus areas in gastric cancer immunotherapy:A comprehensive scientometric and clinical trial review(1999-2023),”which was published in the recent issue of the World Journal of Gastroenterology.We focused on the results of the authors’bibliometric analysis concerning gastric cancer immunotherapy,which they analyzed in depth by compiling the relevant publications of the last 20 years.Before that,we briefly describe the most recent data concerning the epidemiological parameters of gastric cancer(GC)in different countries,attempting to give an interpretation based on the etiological factors involved in the etiopathogenesis of the neoplasm.We then briefly discuss the conservative treatment(chemotherapy)of the various forms of this malignant neoplasm.We describe the treatment of resectable tumors,locally advanced neoplasms,and unresectable(advanced)cases.Special attention is given to modern therapeutic approaches with emphasis on immunotherapy,which seems to be the future of GC treatment,especially in combination with chemotherapy.There is also a thorough analysis of the results of the study under review in terms of the number of scientific publications,the countries in which the studies were conducted,the authors,and the scientific centers of origin,as well as the clinical studies in progress.Finally,an attempt is made to draw some conclusions and to point out possible future directions.

Clinicopathological significance and immunotherapeutic outcome of claudin 18.2 expression in advanced gastric cancer:A retrospective study

Objective: Immunotherapeutic outcomes and clinical characteristics of claudin 18 isoform 2 positive(CLDN18.2-positive) gastric cancer(GC) vary in different clinical studies, making it difficult to optimize antiCLDN18.2 therapy. We conducted a retrospective analysis to explore the association of CLDN18.2 expression with clinicopathological characteristics and immunotherapeutic outcomes in GC.Methods: A total of 536 advanced GC patients from 2019 to 2021 in the CT041-CG4006 and CT041-ST-01clinical trials were included in the analysis. CLDN18.2 expression on ≥40% of tumor cells(2+, 40%) and CLDN18.2 expression on ≥70% of tumor cells(2+, 70%) were considered the two levels of positively expressed GC. The clinicopathological characteristics and immunotherapy outcomes of GC patients were analyzed according to CLDN18.2 expression status.Results: CLDN18.2 was expressed in 57.6%(cut-off: 2+, 40%) and 48.9%(cut-off: 2+, 70%) of patients.Programmed death-ligand 1(PD-L1) and CLDN18.2 were co-expressed in 19.8% [combined positive score(CPS)≥1, CLDN18.2(cut-off: 2+, 40%)] and 17.2% [CPS≥5, CLDN18.2(cut-off: 2+, 70%)] of patients.CLDN18.2 expression positively correlated with younger age, female sex, non-gastroesophageal junction(nonGEJ), and diffuse phenotype(P<0.001). HER2 and PD-L1 expression were significantly lower in CLDN18.2-positive GC(both P<0.05). Uterine adnexa metastasis(P<0.001) was more frequent and liver metastasis(P<0.001)was less common in CLDN18.2-positive GC. Overall survival and immunotherapy-related progression-free survival(ir PFS) were inferior in the CLDN18.2-positive group.Conclusions: CLDN18.2-positive GC is associated with poor prognosis and worse immunotherapeutic outcomes. The combination of anti-CLDN18.2 therapy, anti-PD-L1/PD-1 therapy, and chemotherapy for GC requires further investigation.

Gastric cancer immunotherapy:A scientometric and clinical trial review

This letter is intended to arouse your interest in a recent review of comprehensive scientometrics and clinical trials on immunotherapy for gastric cancer(GC).Our study reviews recent advances in immunotherapy in the field of GC and highlights its new prospects as a treatment for GC.Our research reveals China’s leadership in this field,as well as new therapeutic strategies such as immune checkpoint inhibitors,cellular immunotherapy,and vaccines.The combined findings highlight the potential of immunotherapy to improve survival and quality of life in patients with stomach cancer.We believe that this study will provide important guidance for the future direction of the GC treatment field.

Bile acids inhibit ferroptosis sensitivity through activating farnesoid X receptor in gastric cancer cells

BACKGROUND Gastric cancer(GC)is associated with high mortality rates.Bile acids(BAs)reflux is a well-known risk factor for GC,but the specific mechanism remains unclear.During GC development in both humans and animals,BAs serve as signaling molecules that induce metabolic reprogramming.This confers additional cancer phenotypes,including ferroptosis sensitivity.Ferroptosis is a novel mode of cell death characterized by lipid peroxidation that contributes universally to malignant progression.However,it is not fully defined if BAs can influence GC progression by modulating ferroptosis.AIM To reveal the mechanism of BAs regulation in ferroptosis of GC cells.METHODS In this study,we treated GC cells with various stimuli and evaluated the effect of BAs on the sensitivity to ferroptosis.We used gain and loss of function assays to examine the impacts of farnesoid X receptor(FXR)and BTB and CNC homology 1(BACH1)overexpression and knockdown to obtain further insights into the molecular mechanism involved.RESULTS Our data suggested that BAs could reverse erastin-induced ferroptosis in GC cells.This effect correlated with increased glutathione(GSH)concentrations,a reduced GSH to oxidized GSH ratio,and higher GSH peroxidase 4(GPX4)expression levels.Subsequently,we confirmed that BAs exerted these effects by activating FXR,which markedly increased the expression of GSH synthetase and GPX4.Notably,BACH1 was detected as an essential intermediate molecule in the promotion of GSH synthesis by BAs and FXR.Finally,our results suggested that FXR could significantly promote GC cell proliferation,which may be closely related to its anti-ferroptosis effect.CONCLUSION This study revealed for the first time that BAs could inhibit ferroptosis sensitivity through the FXR-BACH1-GSHGPX4 axis in GC cells.This work provided new insights into the mechanism associated with BA-mediated promotion of GC and may help identify potential therapeutic targets for GC patients with BAs reflux.

Mechanisms of resistance to trastuzumab in HER2-positive gastric cancer

Gastric cancer is one of the most prevalent cancers worldwide,and human epidermal growth factor receptor 2(HER2)-positive cases account for approximately 20%of the total cases.Currently,trastuzumab+chemotherapy is the recommended first-line treatment for patients with HER2-positive advanced gastric cancer,and the combination has exhibited definite efficacy in HER2-targeted therapy.However,the emergence of drug resistance during treatment considerably reduces its effectiveness;thus,it is imperative to investigate the potential mechanisms underlying resistance.In the present review article,we comprehensively introduce multiple mechanisms underlying resistance to trastuzumab in HER2-positive gastric cancer cases,aiming to provide insights for rectifying issues associated with resistance to trastuzumab and devising subsequent treatment strategies.

GIPC1 promotes tumor growth and migration in gastric cancer via activating PDGFR/PI3K/AKT signaling

The high mortality rate associated with gastric cancer(GC)has resulted in an urgent need to identify novel therapeutic targets for GC.This study aimed to investigate whether GAIP interacting protein,C terminus 1(GIPC1)represents a therapeutic target and its regulating mechanism in GC.GIPC1 expression was elevated in GC tissues,liver metastasis tissues,and lymph node metastases.GIPC1 knockdown or GIPC1 blocking peptide blocked the platelet-derived growth factor receptor(PDGFR)/PI3K/AKT signaling pathway,and inhibited the proliferation and migration of GC cells.Conversely,GIPC1 overexpression markedly activated the PDGFR/PI3K/AKT signaling pathway,and promoted GC cell proliferation and migration.Furthermore,platelet-derived growth factor subunit BB(PDGF-BB)cytokines and the AKT inhibitor attenuated the effect of differential GIPC1 expression.Moreover,GIPC1 silencing decreased tumor growth and migration in BALB/c nude mice,while GIPC1 overexpression had contrasting effects.Taken together,our findings suggest that GIPC1 functions as an oncogene in GC and plays a central role in regulating cell proliferation and migration via the PDGFR/PI3K/AKT signaling pathway.

Liquid biopsy for gastric cancer:Techniques,applications,and future directions

After the study of circulating tumor cells in blood through liquid biopsy(LB),this technique has evolved to encompass the analysis of multiple materials originating from the tumor,such as nucleic acids,extracellular vesicles,tumor-educated platelets,and other metabolites.Additionally,research has extended to include the examination of samples other than blood or plasma,such as saliva,gastric juice,urine,or stool.LB techniques are diverse,intricate,and variable.They must be highly sensitive,and pre-analytical,patient,and tumor-related factors significantly influence the detection threshold,diagnostic method selection,and potential results.Consequently,the implementation of LB in clinical practice still faces several challenges.The potential applications of LB range from early cancer detection to guiding targeted therapy or immunotherapy in both early and advanced cancer cases,monitoring treatment response,early identification of relapses,or assessing patient risk.On the other hand,gastric cancer(GC)is a disease often diagnosed at advanced stages.Despite recent advances in molecular understanding,the currently available treatment options have not substantially improved the prognosis for many of these patients.The application of LB in GC could be highly valuable as a non-invasive method for early diagnosis and for enhancing the management and outcomes of these patients.In this comprehensive review,from a pathologist’s perspective,we provide an overview of the main options available in LB,delve into the fundamental principles of the most studied techniques,explore the potential utility of LB application in the context of GC,and address the obstacles that need to be overcome in the future to make this innovative technique a game-changer in cancer diagnosis and treatment within clinical practice.

Application of immune checkpoint inhibitors and microsatellite instability in gastric cancer

In this editorial we comment on the article by Li published in the recent issue of the World Journal of Gastroenterology.We focus specifically on the application of immune checkpoint inhibitors(ICIs)and microsatellite instability(MSI)in gastric cancer(GC).The four pillars of GC management have long been considered,including surgery,chemotherapy,radiotherapy and targeted therapy.However,immunotherapy has recently emerged as a“fifth pillar”,and its use is rapidly expanding.There are four principal strategies for tumor immunotherapy:ICIs,tumor vaccines,adoptive immunotherapy and nonspecific immunomodulators.Of them,ICIs are the most advanced and widespread type of cancer immunotherapy for GC.Recent breakthrough results for ICIs have paved the way to a new era of cancer immunotherapy.In particular,inhibition of the PD-1/PD-L1 axis with ICIs,including nivolumab and pembrolizumab,has emerged as a novel treatment strategy for advanced GC.Unfortunately,these therapies are sometimes associated with often subtle,potentially fatal immune-related adverse events(irAEs),including dermatitis,diarrhea,colitis,endocrinopathy,hepatotoxicity,neuropathy and pneumonitis.We must be aware of these irAEs and improve the detection of these processes to prevent inappropriate discharges,emergency department revisits,and downstream complications.Recent studies have revealed that MSI-high or mismatch-repair-deficient tumors,regardless of their primary site,have a promising response to ICIs.So,it is important to detect MSI before applying ICIs for treatment of GC.

Clinical pathological characteristics of“crawling-type”gastric adenocarcinoma cancer:A case report

BACKGROUND Gastric cancer(GC)is a significant health problem worldwide,and early detection and accurate diagnosis are crucial for improving patient outcomes.Crawling-type gastric adenocarcinoma is a rare subtype of GC that has unique histopathological and clinical characteristics,and its diagnosis and management can be challenging.This pathological type of GC is also rare.CASE SUMMARY Here,we report the case of a patient who underwent ordinary endoscopy,na-rrow-band imaging,and endoscopic ultrasonography intending to determine the extent of tumor invasion and upper abdominal enhanced computed tomography and whether there was tumor metastasis.Then,endoscopic submucosal dissection was performed.After pathological and immunohistochemical examination,the pathological diagnosis was crawling-type gastric adenocarcinoma.This is a very rare and special pathological type of tumor.This case highlights the importance of using advanced endoscopic techniques and pathological examination in diagnosing and managing gastric crawling-type adenocarcinoma.Moreover,the findings underscore the need for continued research and clinical experience in this rare subtype of GC to improve patient outcomes.CONCLUSION The“crawling-type”GC is a rare and specific tumor pathology.It is difficult to identify and diagnose gliomas via endoscopy.The tumor is ill-defined,with a flat appearance and indistinct borders due to the lack of contrast against the background mucosa.Pathology revealed that the tumor cells were hand-like,so the patient has diagnosed with“crawling-type”gastric adenocarcinoma.

Evaluating the influence of sarcopenia and myosteatosis on clinical outcomes in gastric cancer patients undergoing immune checkpoint inhibitor

BACKGROUND The development and progression of gastric cancer(GC)are closely linked to the nutritional status of patients.Although immunotherapy has been demonstrated to be clinically effective,the relationships of sarcopenia and myosteatosis with the use of immune checkpoint inhibitors(ICIs)in patients with gastric cancer remain to be characterized.METHODS We performed a retrospective study of patients who were undergoing immuno-therapy for GC.For the evaluation of sarcopenia,the optimal cut-off value for the skeletal muscle index was established using receiver operating characteristic analysis of data obtained from pre-treatment computed tomography images at the L3 vertebral level.Myosteatosis was defined using the mean skeletal muscle density(SMD),with a threshold value of<41 Hounsfield units(HU)for patients with a body mass index(BMI)<25 kg/m^(2)and<33 HU for those with a BMI≥25 kg/m^(2).The log-rank test was used to compare progression-free survival(PFS)and overall survival(OS),and a Cox proportional hazard model was used to identify prognostic factors.Nomograms were developed to predict the PFS and OS of patients on the basis of the results of multivariate analyses.RESULTS We studied 115 patients who were undergoing ICI therapy for GC,of whom 27.4%had sarcopenia and 29.8%had myosteatosis.Patients with sarcopenia or myosteatosis had significantly shorter PFS and OS than those without these conditions.Furthermore,both sarcopenia and myosteatosis were found to be independent predictors of PFS and OS in patients with GC administering an ICI.The prediction models created for PFS and OS were associated with C-indexes of 0.758 and 0.781,respectively.CONCLUSION The presence of sarcopenia or myosteatosis is a reliable predictor of the clinical outcomes of patients with GC who are undergoing treatment with an ICI.