Low Expression of E-Cadherin and Cdh1 Variants Associated with Diffuse Gastric Cancer

ABSTRACT Background Reduced or null expression of E-cadherin protein is a frequent cause of diffuse gastric cancer (DGC). More than 50% of patients with DGC present somatic variants in CDH1 gene. Objectives The objectives of this study were to study E-cadherin expression and identify variants in the CDH1 gene in gastric tumors of patients with DGC. Methods We studied 18 Mexican DGC patients who attended a hospital of the Mexican Social Security Institute; E-cadherin expression was determined by immunohistochemistry, and variants were identified by Sanger sequencing in promoter and coding regions. Predictive analysis was performed using PolyPhen-2 and HOPE software. Results We found that 56% of DGC patients showed reduced expression of E-cadherin. All patients carried CDH1 variants; overall, 12 different CDH1 variants were identified. Predictive analysis revealed that the rs114265540 variant was probably damaging, with a value of 0.985, indicating a functional impact on the E-cadherin protein. Variants rs34939176 and rs33964119 were identified as risk factors for DGC (odds' ratios [OR] = 31.3, 95% CI 6.3-154.0, p < 0.001; OR = 6.1, 95% CI 2.0-19.0, p < 0.001, respectively) given their elevated frequency and by comparing it with those reported for MXL population in the 1000 Genomes Project database. Conclusions In this Mexican population, the percentage of diffuse gastric tumors with reduced expression of E-cadherin was similar to that reported in other populations. All gastric tumors of DGC patients studied had somatic CDH1 gene variants; however, the rs114265540, rs34939176, and rs33964119 variants were importantly related to DGC.

Predicting Pathogenicity of CDH1 Gene Variants in Patients with Early-onset Diffuse Gastric Cancer from Western Mexico

ABSTRACT Background: Early-onset diffuse gastric cancer (EODGC) occurs at or before 50 years of age. Pathogenic mutations and germline deletions in the CDH1 gene (E-cadherin) are well-documented genetic factors associated with the causes of EODGC. Objective: The objective of the study was to study CDH1 germline variants and their potential functional impact in patients with EODGC in a Mexican population. Methods: We studied seven EODGC patients from a biomedical research center in western Mexico. Variants were identified by Sanger sequencing and multiplex ligation-dependent probe amplification. The DeepSEA and SNPClinic v.1.0 software and the Ensembl (1000 Genomes Project, 1kGP) and ClinVar databases were used to predict functional single-nucleotide polymorphisms (SNPs). The genetic admixture of the Mexican patients was corroborated by 22 short tandem repeat loci genotyping and structure analysis. Results: We found 12 germline CDH1 variants in all EODGC patients, and all of them are considered as polymorphisms: rs34561447, rs5030625, rs16260, rs1330727101, rs28372783, rs942269593, rs3743674, rs1801552, rs34939176, rs33964119, rs3556654, and rs1801026. The prediction of regulatory SNPs in the promoter suggests a role for a retrovirus in EODGC that induces the transcription of interferon-related genes through toll-like receptor-interferon response factor 3 signaling, as three SNPs in the CDH1 promoter alter three binding sites for this transcription factor. In addition, SNPs rs28372783 and rs1801026 could alter upstream stimulatory factors 1 (USF1)/USF2-mediated telomerase-dependent lymphocyte activation in EODGC. Other interesting result is a CTCF-dependent shorter CDH1 isoform lacking exon 14, probably due to exon-skipping mediated by rs33964119. Conclusions: Classical pathogenic germline mutations in the CDH1 gene were not found in these 7 EODGC patients. However, the in silico approaches revealed the possible involvement of a retrovirus and a shorter E-cadherin isoform in EODGC. Nevertheless, further in vitro and in vivo assays are needed to confirm these predictions.

Cáncer gástrico hereditario: indicaciones de estudio genético ¿cuando y a quiénes? / Hereditary gastric cancer: indications of genetic study: when and to whom?

Resumen El objetivo de esta revisión es realizar una actualización de los conocimientos actuales en cáncer gástrico hereditario, especialmente enfocado a que pacientes tienen indicación de estudio genético y su manejo clínico. En un 5-10% de los cánceres gástricos existe un patrón familiar. Los cánceres hereditarios, a diferencia de los esporádicos, se asocian a mutaciones germinales en un gen específico. En cáncer gástrico hereditario difuso (HDGC), se han identificado mutaciones en genes específicos asociados a la enfermedad (CDH1 y CTNNA1). El síndrome clínico de HDGC se asocia a la aparición a temprana edad, típicamente alrededor de los 40 años de múltiples focos de cáncer gástrico (CG) de tipo difuso, frecuentemente con células en anillo de sello y la aparición de cáncer de mama de tipo lobulillar. De los pacientes que cumplen los criterios clínicos de HDGC, el 20-50% presenta una mutación del gen CDH1. La presencia de una mutación confiere un riesgo de aparición de CG difuso de 67-70% para hombres y de 56-83% para mujeres; y un riesgo de 42% de cáncer de mama a lo largo de la vida del paciente. Se consideran actualmente como indicaciones para asesoría y estudio genético; la presencia de 2 o más familiares con CG, uno confirmado difuso, independiente de la edad; y en segundo lugar individuos con CG menores de 40 años de edad, sin historia familiar previa. Dentro del manejo de es estos pacientes es clave un equipo multidisciplinario y las principales alternativas de manejo son el seguimiento endoscópico y la gastrectomía profiláctica. Así como se ha avanzado en definir el mejor manejo clínico de estos pacientes, esta patología también representa una área de importante interés en investigación.

The aim is to update the current knowledge in hereditary gastric cancer, especially the current indications for genetic testing and its clinical management. In 5-10% of gastric cancers there is a familiar pattern. Hereditary cancers, unlike sporadic cancers, are associated with germline mutations in a specific gene. In hereditary diffuse gastric cancer (HDGC), mutations have been identified in specific genes associated with the disease (CDH1 y CTNNA1). The clinical syndrome of HDGC is associated with the appearance at an early age, typically around 40 years, of multiple foci of diffuse gastric cancer (GC), frequently with signet ring cells and the appearance of lobular type breast cancer. Twenty to fifty percent of patients who meet the clinical criteria for HDGC have a mutation in the CDH1 gene. The presence of a mutation confers a risk of diffuse CG of 67-70% for men and 56-83% for women; and a 42% risk of breast cancer throughout the life of the patient. The main current indications for genetic counseling and study are the presence of 2 or more relatives with CG, one confirmed diffuse, regardless of age; and individuals with CG less than 40 years of age, without previous family history. A multidisciplinary team is key and the main management alternatives are endoscopic follow-up and prophylactic gastrectomy. Just as there has been progress in defining the best clinical management of these patients, this pathology also represents an area of important research interest.

Association of clinicopathological features with E-cadherin (CDH1) gene-160 C>A promoter polymorphism in Turkish colorectal cancer patients

Background and Aim of Study: The role of E-cadherin (CDH1) gene-160 C>A (rs16260) promoter polymorphism in colorectal cancer (CRC) still remains inconclusive. The aim of this study is to investigate the associations between the CDH1-160 C>A polymorphism with the susceptibility and clinicopathological development of CRC in the Turkish patients. To our knowledge, this is the first report examining the role of CDH1 polymorphism in Turkish CRC patients. Materials and Methods: A total of 92 colorectal carcinoma cases (including 62 colon and 30 rectal cancer patients) and the corresponding adjacent normal tissues as controls were studied. The polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism analysis. Clinicopathological features including patient's age, gender, tumor stage, and tumor location (colon/rectum) were compared statistically with the polymorphism status. Results: There was no significant difference in both genotype and allele frequencies of the CDH1 polymorphism between colorectal tumor cases and normal samples (P = 0.472 and 0.508, respectively). Furthermore, no significant associations were observed between the CDH1 polymorphism status and age, gender, tumor stage, and tumor location of the colorectal tumor cases (all P > 0.05). Conclusions: These results indicate that CDH1-160 C>A polymorphism does not contribute to the genetic susceptibility of CRC and the polymorphism may not be a direct effect on the progression of the disease in Turkish CRC patients.

The Clinical Significance Of Rassf1a And Cdh1 Hypermethylation In Breast Cancer Patients

Introduction:Aberrant DNAmethylation patterns in serum DNAmight be used as a biomarker for the early diagnosis and management of cancer patients. The aim of present study was to evaluate DNAmethylation of RASSF1Aand CDH1 in circulating cell free DNA(cfDNA) from serum and paired tissue DNAsamples of breast cancer patients. Material and methods: Methylation-specific PCR was used to assess the methylation status of the two genes in serum and paired tissue sample DNAof 50 breast cancer patients. Biochemical parameters were assessed using an electrochemiluminescence analyzer. Results: Significant correlation found between methylation status of RASSF1A and CDH1 in serum and paired tissue samples of patients. Among clinicopathological findings, CDH1 methylation showed significant association with advance staging and tumor and methylation of RASSF1A exhibited significant association with progesterone receptor and estrogen receptor status in both serum and paired tissue. Vitamins levels were significantly high in cases compared to control group. High folic acid levels were significantly associated with the RASSF1Amethylation. Conclusions: These findings suggest that methylation of cfDNAmay be important in the early detection of breast cancer.

Methylation status of CDH1 gene in invasive ductal carcinoma of breast and its clinical significance / 重庆医学

Objective To explore the significance of gene promoter methylation of CDH1 in breast invasive ductal carcinoma.Methods The gene promoter methylation of CDH1 and E-cadherin expression status in breast cancer tissues,adjacent tissues and normal breast tissues were detected by using methylation specific polymerase chain reaction (PCR) and immunohistochemistry (SP) method.The clinicopathological data (genetic background,age,tumor size,axillary lymph node metastasis,tumor cells grading,clinical staging and molecular subtype) were collected,and analysed the clinical significance of gene promoter methylation of CDH1 in breast cancer.Results Among the 250 patients with breast cancer,113 cases were found gene promoter methylation of CDH1,and the methylation rate was 45.20％.Compared with patients with unmethylated CDH1 gene promoter,the E-cadherin protein expression was reduced in patients with methylated CDH1 gene promoter,there was statistically significant difference (x2 =21.360,P＜0.01).The univariate analysis showed that statistically significant differences were found in axillary lymph node metastasis (x2=19.086,P＜0.01),histological grading of tumor (x2 =8.487,P=0.014),CerbB-2 expression (x2=9.475,P=0.002) and molecular typing (x2 =25.482,P＜0.01) between patients with methylated and unmethylated CDH1 gene promoter.The COX regression analysis showed that there was significant difference in 5-year survival rate between patients with methylated and unmethylated CDH1 gene promoter(P＜0.01).Conclusion Methylation of CDH1 gene promoter causes decreasedexpression of mRNA,and is associated with axillary lymph node metastasis in breast cancer,which suggests that methylation of CDH1 gene promoter plays a certain role in breast cancer progression.

Progress in Diagnosis and Treatment of Hereditary Diffuse Gastric Cancer / 胃肠病学

Hereditary diffuse gastric cancer (HDGC) is an autosomal dominant inherited disease,and may be related to the mutation of CDH1 or CTNNA1 genes.Microscopically,signet-ring cell carcinoma is suggested frequently in endoscopic biopsy or gastrectomy specimens.Some patients may have concomitant extra-stomach tumor (frequently breast cancer in females).Detection of CDH1 gene mutation should be performed in high-risk individuals,and diagnosis and treatment should be carried out by a multidisciplinary team.Prophylactic gastrectomy is recommended for those with pathogenic CDH1 mutation.Endoscopic surveillance is an option for those with CDH1 mutation of undetermined significance and those without germline CDH1 mutation.This review discussed the concept,genetic characteristics,clinicopathological features and genetic screening of HDGC for providing a reference for clinicians.

Helicobacter pylori Eradication Modulates Aberrant CpG Island Hypermethylation in Gastric Carcinogenesis / 대한소화기학회지

BACKGROUND/AIMS: Helicobacter pylori infection induces aberrant DNA methylation in gastric mucosa. We evaluated the long-term effect of H. pylori eradication on promotor CpG island hypermethylation in gastric carcinogenesis. METHODS: H. pylori-positive patients with gastric adenoma or early gastric cancer who underwent endoscopic resection were enrolled. According to H. pylori eradication after endoscopic resection, the participants were randomly assigned to H. pylori eradication or non-eradication group. H. pylori-negative gastric mucosa from normal participants provided the normal control. CpG island hypermethylation of tumor-related genes (p16, CDH1, and RUNX-3) was evaluated by quantitative MethyLight assay in non-tumorous gastric mucosa. The gene methylation rate and median values of hypermethylation were compared after one year by H. pylori status. RESULTS: In H. pylori-positive patients, hypermethylation of p16 was found in 80.6%, of CDH1 in 80.6%, and of RUNX-3 in 48.4%. This is significantly higher than normal control (p16, 10%; CDH1, 44%; RUNX-3, 16%) (p<0.05). In the H. pylori eradication group, methylation rates of p16 and CDH1 decreased in 58.1% and 61.3% of the patients, and the median values of hypermethylation were significantly lower at one year compared with the non-eradication group. However, RUNX-3 hypermethylation did not differ significantly at one year after H. pylori eradication. The non-eradication group hypermethylation did not change after one year. CONCLUSIONS: H. pylori infection was associated with promotor hypermethylation of genes in gastric carcinogenesis, and H. pylori eradication might reverse p16 and CDH1 hypermethylation.

Presymptomatic Identification of CDH1 Germline Mutation in a Healthy Korean Individual with Family History of Gastric Cancer

Gastric cancer (GC) is one of the most common cancers with high morbidity and mortality. Familial GC is seen in 10% of cases, and approximately 3% of familial GC cases arise owing to hereditary diffuse gastric cancer (HDGC). CDH1, which encodes the protein E-cadherin, is the only gene whose mutations are associated with HDGC. Screening for the familial GC-predisposing gene has been neglected in high-risk countries such as Korea, China, and Japan, where all the cases have been attributed to Helicobacter pylori or other carcinogens. Screening for the GC-causing CDH1 mutation may provide valuable information for genetic counseling, testing, and risk-reduction management for the as-yet unaffected family members. An asymptomatic 44-yr-old Korean male visited our genetic clinic for consultation owing to his family history of GC. Eventually, c.1018A>G in CDH1, a known disease-causing mutation, was found. As of the publication time, the individual is alive without the evidence of GC, and is on surveillance. To our knowledge, this is the first Korean case of presymptomatic detection of CDH1 mutation, and it highlights the importance of genetic screening for individuals with a family history of GC, especially in high-risk geographical areas.

The expression of CDH1 gene methylation in patients with esophagus and stomach double primary carcinoma and its significance / 中华消化杂志

Objective To study the changes of CDH1 gene promoter CpG island methylation and its clinical significance in patients with esophagus and stomach double primary carcinoma(ESDC).Methods The expression of CDH1 gene methylation in cancerous tissues and adjacent cancerous tissues in 18 cases of ESDC were detected using methylation-specific PCR method. Results Eighteen patients were endoscopically diagnosed as ESDC between Jan. 2007 and Sep. 2009 in the 4th Hospital Affiliated to Hebei Medical University. The positive methylation of CDH1 gene in tissues of esophageal squamous cell carcinoma (ESCC)and adjacent cancer were 66.7% and 33. 3%, respectively, with significant difference (χ2= 4. 167, P = 0. 031). Whereas the positive methylation of CDH1 gene in tissues of gastric carcinoma (GA) and adjacent cancer were 77.8% and 44.4%, respectively, without statistical difference (χ2=1.786, P= 0. 180). There was no significant difference (P=0. 500) in positive rate of CDH1 gene methylation between ESCC tissues and GA tissues in same individual with ESDC. For 18 patients with ESDC, consistent change of CDH1 methylation in tissues of two kinds of cancers was found in 16 patients with a total agreement of 88.9 % (positive agreement of 66.7 % and negative agreement of 22. 2%). Statistical analysis showed a significant correlation between two groups (P = 0. 005). Conclusion In patients with ESDC, there is a high consistency of CDH1 methylation change, between ESCC and GA,which suggests that two kinds of cancer may have similar risk factors and molecular mechanisms.

CDH1 methylation of E-cadherin gene in human intrahepatic cholangiocarcinomas: Correlation between clinico-pathologic parameters and patients' survival / 第二军医大学学报

Objective: To investigate CDH1 methylation of epithelial cadherin(E-cadherin) gene in intrahepatic cholangio carcinomas (ICCs). Methods: Forty-two liver samples were obrained from ICC patients (32 males and 10 females) during surgical resection in Eastern Hepatobiliary Surgery Hospital. The ICC tissue samples and the adjacent tissue samples were paraffin-embedded and fresh ice-frozen. A methylation-specific polymerase chain reaction (MSP) was used for analyzing the methylation of CDH1 gene; E-cadherin protein and mRNA expression was detected by immunohistochemical method and RT PCR analysis, respectively. Results: The methylation rate of CDHI was 28.6% in ICC patients. The expression of E-cadherin mRNA and protein was decreased in 64.3% and 69.1% of the samples, respectively. The methylation of CDH1 gene was correlated with the expression of E-cadherin protein and mRNA and metastasis of ICCs (P=0.008, P=0.031, and P=0.020, respectively), but not with the prognosis of ICC. The abnormal expression of E-cadherin was significantly correlated with the survival of patients (P=0.002). Conclusion: The methylation of CDH1 gene and down-regulation of E-cadherin are frequently seen in ICC patients, indicating that they may be closely related to the development and progression of ICCs.

Differential expression of E-cadherin gene in human neuroepithelial tumors

Cadherins are cell-to-cell adhesion molecules that play an important role in the establishment of adherent-type junctions by mediating calcium-dependent cellular interactions. The CDH1 gene encodes the transmembrane glycoprotein E-cadherin which is important in maintaining homophilic cell-cell adhesion in epithelial tissues. E-cadherin interacts with catenin proteins to maintain tissue architecture. Structural defects or loss of expression of E-cadherin have been reported as a common feature in several human cancer types. This study aimed to evaluate the expression of E-cadherin and their correlation with clinical features in microdissected brain tumor samples from 81 patients, divided into 62 astrocytic tumors grades I to IV and 19 medulloblastomas, and from 5 white matter non-neoplasic brain tissue samples. E-cadherin (CDH1) gene expression was analyzed by quantitative real-time polymerase chain reaction. Mann-Whitney, Kruskal-Wallis, Kaplan-Meir, and log-rank tests were performed for statistical analyses. We observed a decrease in expression among pathological grades of neuroepithelial tumors. Non-neoplasic brain tissue showed a higher expression level of CDH1 gene than did neuroepithelial tumors. Expression of E-cadherin gene was higher in astrocytic than embryonal tumors (P = 0.0168). Low-grade malignancy astrocytomas (grades I-II) showed higher CDH1 expression than did high-grade malignancy astrocytomas (grades III-IV) and medulloblastomas (P < 0.0001). Non-neoplasic brain tissue showed a higher expression level of CDH1 gene than grade I malignancy astrocytomas, considered as benign tumors (P = 0.0473). These results suggest that a decrease in E-cadherin gene expression level in high-grade neuroepithelial tumors may be a hallmark of malignancy in dedifferentiated tumors and that it may be possibly correlated with their progression and dissemination.

Loss of E-cadherin Function is Suggested to be Associated with Peritoneal Seeding in Colorectal Cancer

PURPOSE: We investigated whether the loss of E-cadherin function was related to the peritoneal seeding in colorectal carcinomas. METHODS: Eleven patients who had undergone a palliative resection for a colorectal carcinoma, with peritoneal seeding, were enrolled onto the study. The primary tumors and seeding nodules were analyzed with regarded to mutations in the expressions of the CDH1 and protein of E-cadherin using SSCP, direct sequencing and immunohistochemical staining. RESULTS: In the primary tumors, the E-cadherin was normally expressed in 9 of the 11 cases, with 2 cases showing a reduced expression. In the seeding nodules, the E-cadherin was normally expressed in 6 of the 11 cases, with 5 cases showing a reduced expression. The degree of E-cadherin expression in the seeding nodules was significantly decreased comparing to that in the primary tumors (Pctaggt (intron 2) and GTG>GTA (codon 782). CONCLUSION: The loss of E-cadherin expression might be related to peritoneal seeding. The functional derangement of E-cadherin in peritoneal seeding could possibly be caused by a mechanism, such as promoter methylation, rather than the mutation of the CDH1.