Correlation Study Of Screening Biomarker In Intestinal Metaplasia Progressed To Gastric Caner On Bioinformatics Analysis And The Predictive Value Of OLFM4

PART Ⅰ Correlation Study of Screening Biomarker in Intestinal Metaplasia Progressed to Gastric Caner on Bioinformatics AnalysisObjective: Early detection of gastrointestinal metaplasia(GIM-GC)remains challenging.This study aims to screen and identify potential candidate genes and biomarkers related to GIM-GC.Methods: A microarray dataset of gastrointestinal metaplasia(GSE78523)was downloaded from the GEO database.Differentially expressed genes(DEGs)were screened between GIM-GC and normal control group.Go functional annotation and KEGG pathway enrichment analysis modules were used to identify the functions and pathways of differentially expressed genes enrichment.Protein interaction networks were used to evaluate protein-protein interactions and identify important modules and core genes.String and Cytoscape are used to assess protein-protein interaction networks and to identify important modules and core genes.KM-plotter was used to analyze the relationship between the expression level of core genes and the prognosis of gastric adenocarcinoma.The intersection genes of DEGs of the three groups(intestinal metaplasia group,intestinal metaplasia cancer-free group and normal control group)were compared pair by Venn diagram,and the only common differentially expressed gene among the intersection genes and core genes was identified.The expression of the only common differentially expressed gene OLFM4 was preliminarily verified in gastric adenocarcinoma using the tumor genome atlas data set.Results: Compared with the normal control group,257 DEGs were found in the GIM-GC group,including 217 up-regulated genes and 40 down-regulated genes.GO enrichment indicated that up-regulated DEGs were mainly enriched in the biosynthesis of lipoproteins and the binding of phospholipids,which were components of plasma membrane.The down-regulated DEGs are mainly involved in digestion and hormonal activity and exist in the extracellular space.KEGG pathway analysis showed that DEGs were mainly involved in fat digestion and absorption and gastric acid secretion.The most important gene modules are related to O-glycan processing,exosomes,hormone activity,and vitamin and fat digestion and absorption.A total of 11 central genes were identified.The survival analysis showed that Apo B,FABP1,CDX2,GCG,HNF4 A,SLC26A3,CFTR,MUC5 AC,OLFM4,SI and other genes were related to the prognosis of gastric cancer.OLFM4 is the most important differentially expressed gene for the identification of GIM-GC.Conclusion: DEGS and HUB genes contribute to the understanding of the molecular mechanism of GIM-GC.OLFM4 may be a key biomarker of GIM-GC.PART Ⅱ Expression And Clinical Significance of OLFM4 In Intestinal Metaplasia And Gastric CancerObjective: To investigate the expression and significance of OLFM4(OLFM4)in Gastric mucosal and Intestinal Metaplasia(GIM)of Gastric carcinoma,and to search for molecular markers of Gastric and Intestinal Metaplasia.Methods: Immunohistochemical staining was used to detect the expression of OLFM4 protein in 93 cases of chronic gastritis,103 cases of GIM,29 cases of severe dysplasia/high-grade neoplasia with GIM,80 cases of gastric cancer with GIM and corresponding paracancerous intestinal metaplasia.The expression levels of OLFM4 protein in GIM tissues of different degrees were detected.The expression of OLFM4 gene in gastritis,intestinal metaplasia,gastric cancer and paracancerous GIM was further studied from mRNA level.Special staining method was used to detect the expression of OLFM4 protein in the adjacent GIM of type I,II and III,and the differences of OLFM4 protein expression among groups were compared,and the relationship between OLFM4 protein expression and clinicopathological parameters of gastric cancer and prognosis of gastric cancer patients were analyzed.Results: OLFM4 protein was not expressed in chronic superficial gastritis group,but was highly expressed in intestinal metaplasia,dysplasia and gastric cancer groups,the difference was statistically significant(P<0.05).The relative expression level of OLFM4 gene in GIM and gastric cancer group was significantly higher than that in chronic superficial gastritis group(P<0.05).The positive expression rate of OLFM4 in moderate and severe intestinal metaplasia group was higher than that in mild GIM group(P<0.05),and the positive expression rates were 77.8% and 60.1%,respectively.The expression intensity of OLFM4 in the moderate and severe GIM group was higher than that in the mild GIM group(P<0.05).The mean expression intensity of OLFM4 in the moderate and severe GIM group was 5.740 points,while the mean expression intensity in the mild GIM group was 3.677 points.The positive expression rate of OLFM4 in early gastric cancer group was higher than that in advanced gastric cancer group(72.7% and 58.6%,respectively),but the difference between the two groups was not statistically significant(P>0.05).The positive expression rate of OLFM4 in the paracancer intestinal metaplasia group(71.3%)was higher than that in the non-paracancer GIM group(59.2%),and there was no statistically significant difference between the two groups(P>0.05).The expression of OLFM4 protein was consistent in cancer foci and paracancillary intestinal metaplasia tissues(Kappa value =0.245,P < 0.05),and the relative expression of OLFM4 gene in gastric cancer group and paracancillary intestinal metaplasia group showed no statistically significant difference(t=0.385,P>0.05).The detection rate of paracancerous GIM of type III was the highest(84.1%),and the expression of OLFM4 in GIM of type I,II and III had no statistical significance(P>0.05).The expression of OLFM4 protein in gastric cancer tissues was not related to gender,age and depth of invasion(all P>0.05),but was related to Lauren’s type,degree of differentiation and clinical stage(all P<0.05).The positive expression rate of OLFM4 protein in intestinal gastric cancer group(80%)was higher than that in diffuse gastric cancer group(53.6%)and mixed gastric cancer group(50%),and the difference was statistically significant(P<0.05).The positive expression rate of OLFM4 protein in moderately and highly differentiated adenocarcinoma groups(82.6%)was significantly higher than that in poorly differentiated adenocarcinoma and mucinous aden-o carcinoma groups(54.4%),with statistical significance(P<0.05).The positive expression rate of OLFM4 protein in the group without lymph node metastasis(65.3%)was higher than that in the group with lymph node metastasis(58.1%),and the difference was not statistically significant(P>0.05).The positive expression rate of OLFM4 protein in I/ II stage gastric cancer(73.3%)was significantly higher than that in III/IV stage gastric cancer(48.6%),and the difference was statistically significant(P<0.05).Median survival time was 56.45± 8.63 months(95%CI: 39.53-73.37)in the OLFM4 negative group and 82.89±5.92 months(95%CI: 71.28-94.51)in the positive group.The cumulative survival rate of OLFM4 protein positive group was higher than that of negative group(P<0.05).The expression of OLFM4 and lymph node metastasis were independent risk factors affecting the prognosis of gastric cancer patients(P<0.05).Conclusions:(1)The expression of OLFM4 protein in gastric mucosa,intestinal metaplasia and gastric cancer group was higher than that in chronic superficial gastritis group.(2)As the degree of GIM increases,the expression of OLFM4 becomes more and more extensive during the progression of GIM to gastric cancer,and the expression of OLFM4 is consistent in both focal and paracancerous GIM.(3)The expression intensity of OLFM4 was basically consistent with the progression pattern of mild intestinal metaplasia-moderate to severe intestinal metaplasia-dysplasia-early gastric cancer,and OLMF4 may be used as a molecular marker to predict intestinal metaplasia and cancer.(4)OLFM4 was highly expressed in stage I/II gastric cancer,well differentiated gastric cancer,and enteric gastric cancer.In patients with gastric cancer with intestinal metaplasia,the overexpression of OLFM4 suggests a better prognosis.(5)OLFM4 may be used as a molecular marker of intestinal metaplasia and a therapeutic target to reverse the progression of intestinal metaplasia.(6)The expression pattern of OLFM4 gene is basically consistent with that of OLFM4 protein,which indicates that OLFM4 gene is involved in the occurrence and development of intestinal metaplasia and the early and progression of carcinogenesis,suggesting that OLFM4 can be used as a sensitive biomarker for early detection of intestinal metaplasia and carcinogenesis and as a prognostic indicator of gastric cancer.PART Ⅲ Analysis of Risk Factors Related to Early Carcinogenesis of Gastrointestinal Metaplasia And Predictive Value of OLFM4Objective: To investigate the clinical characteristics of gastrointestinal metaplasia and gastric cancer with intestinal metaplasia,search for the molecular markers of early carcinogenesis of gastrointestinal metaplasia,and to establish the prediction model of early diagnosis of intestinal metaplasia,so as to provide a reliable theoretical basis for early detection and diagnosis of gastric cancer.Methods: A total of 212 patients with gastric cancer who were diagnosed with intestinal metaplasia or with intestinal metaplasia in Guangxi Medical University and Nanning Second People’s Hospital from January 2012 to June 2020 were collected.According to the presence or absence of intestinal metaplasia with cancer,the patients were divided into intestinal metaplasia cancer-free group(GIM).Early carcinogenesis with intestinal metaplasia(GIM-EGC)and advanced gastric cancer with intestinal metaplasia(GIM-AGC).Analysis of three groups of the clinical pathological characteristics and under gastroscope characteristic change,no with carcinoma by immunohistochemical staining method to detect the intestinal metaplasia of organization and the associated with intestinal metaplasia OLFM4 protein expression in cancerous tissue,further analyzing the risk factors of early intestinal metaplasia canceration,establish the forecast model of early detection of gastric metaplasia canceration.Results: The age of GIM group was relatively young,and the majority of patients were under 55 years old(56/105,54.36%),while the majority of patients in GIM-EGC and GIM-AGC groups were over 55 years old,the difference between the three groups was statistically significant(P<0.05),but there was no statistically significant difference in the age of GIM-EGC and GIM-AGC groups.Male was the most common site of the disease in the three groups,and the lower 1/3 of the stomach(gastric antrum and gastric Angle)was the most common site.The lesions in the GIM and GIM-EGC groups were mainly <2cm,while those in the GIM-AGC group were mainly ≥2cm.The lesions in the GIM-AGC group were larger in diameter than those in the GIM and GIM-EGC groups,but there was no significant difference in the size of the lesions in the GIM and GIM-EGC groups(P>0.05).The endoscopic manifestations of the GIM group were mainly the swelling erosion(0-IIA,0-I type),while the GIM-EGC group was mainly the flat and indented lesions(0-IIC,0-IIB and III type),and the difference between the three groups was statistically significant(P<0.05).There was no significant difference in Hp infection rate among the three groups.OLFM4 was positively expressed in 61 cases and negative in 42 cases in the GIM group,with a positive expression rate of 59.2%;positively expressed in 39 cases and negative in 12 cases in the GIM-EGC group,with a positive expression rate of 76.5%;positively expressed in 34 cases and negative in 24 cases in the GIM-AGC group,with a positive expression rate of 58.6%.There was no statistically significant difference among the three groups(P>0.05),but the positive expression rate of GIM-EGC group was significantly higher than that of GIM group,and the difference was statistically significant(P<0.05).Gastroscopic findings of flat/indentation lesions in the context of intestinal metaplasia are independent risk factors for the diagnosis of intestinal metaplasia with early carcinogenesis.The regression model combining age,sex,OLFM4 and the risk factors of intestinal metaplasms with flatness/depression had an area under the curve as high as 0.913(95%CI :0.873-0.970,sensitivity of 92.2%,specificity of 68.9%,P=0.000).Conclusions: intestinal metaplasia with early cancer mainly IIc,IIb and shallow ulcer lesions,no intestinal metaplasia with carcinoma mainly uplift lesions(type IIa),GIM and the occurrence of gastric cancer were correlated with gender,endoscopic found bowel appear under the background of IIc,IIb and shallow ulcer lesions,need to be vigilant presence of intestinal metaplasia with early canceration.OLFM4 can be used as a molecular marker of GIM and early carcinogenesis,and the prediction model of OLFM4 combined with endoscopic changes,gender and age factors can be established,which may help to improve the early diagnosis rate of intestinal metaplasia and reduce the misdiagnosis and missed diagnosis of early gastric cancer.