[Challenging Case of Primary Renal Castleman's Disease Accompanied with Bacterial Pyelonephritis].

Castleman's disease is a rare lymphoproliferative disease, mostly found in the mediastinum. The number of Castleman's disease cases involving the kidneys is still limited. We report a case of primary renal Castleman's disease sporadically detected during a regular health check-up as pyelonephritis with ureteral stones. In addition, computed tomography showed renal pelvic and ureteral wall thickening with paraaortic lymphadenopathy. A lymph node biopsy was performed, but it did not confirm either malignancy or Castleman's disease. The patient underwent open nephroureterectomy for diagnostic and therapeutic purposes. The pathological diagnosis was renal and retroperitoneal lymph node Castleman's disease with pyelonephritis.

Genetic associations of single nucleotide polymorphisms in the l-DOPA receptor (GPR143) gene with severity of nicotine dependence in Japanese individuals, and attenuation of nicotine reinforcement in Gpr143 gene-deficient mice.

l-3,4-dihydroxyphenylalanine (l-DOPA) is a candidate neurotransmitter. l-DOPA is released by nicotine through nicotinic receptors. Recently, G-protein coupled receptor GPR143, was identified as a receptor for l-DOPA. In this study, genetic association studies between GPR143 genetic polymorphisms and smoking behaviors revealed that the single-nucleotide polymorphism rs6640499, in the GPR143 gene, was associated with traits of smoking behaviors in Japanese individuals. In Gpr143 gene-deficient mice, nicotine-induced hypolocomotion and rewarding effect were attenuated compared to those in wild-type mice. Our findings suggest the involvement of GPR143 in the smoking behaviors.

Genome-wide association study identifies gastric cancer susceptibility loci at 12q24.11-12 and 20q11.21.

Gastric cancer is the third leading cause of cancer mortality in Japan and worldwide. Although previous studies identify various genetic variations associated with gastric cancer, host genetic factors are largely unidentified. To identify novel gastric cancer loci in the Japanese population, herein, we carried out a large-scale genome-wide association study using 6171 cases and 27 178 controls followed by three replication analyses. Analysis using a total of 11 507 cases and 38 904 controls identified two novel loci on 12q24.11-12 (rs6490061, P = 3.20 × 10-8 with an odds ratio [OR] of 0.905) and 20q11.21 (rs2376549, P = 8.11 × 10-10 with an OR of 1.109). rs6490061 is located at intron 19 of the CUX2 gene, and its expression was suppressed by Helicobacter pylori infection. rs2376549 is included within the gene cluster of DEFB families that encode antibacterial peptides. We also found a significant association of rs7849280 in the ABO gene locus on 9q34.2 (P = 2.64 × 10-13 with an OR of 1.148). CUX2 and ABO expression in gastric mucosal tissues was significantly associated with rs6490061 and rs7849280 (P = 0.0153 and 8.00 × 10-11 ), respectively. Our findings show the crucial roles of genetic variations in the pathogenesis of gastric cancer.

Robust quantitative assessments of cytosine modifications and changes in the expressions of related enzymes in gastric cancer.

BACKGROUND: The rediscovery of 5-hydroxymethylcytosine, the ten-eleven translocation (TET) family, thymine-DNA glycosylase (TDG) and isocitrate dehydrogenase (IDH) have opened new avenues in the study of DNA demethylation pathways in gastric cancer (GC). We performed a comprehensive and robust analysis of these genes and modified cytosines in gastric cancer. METHODS: Liquid chromatography mass spectrometry/mass spectrometry (LC-MS/MS) was used to assess 5-methyldeoxycytidine (5-mC), 5-hydroxymethyldeoxycytidine (5-hmC), 5-formyldeoxycytidine (5-fC) and 5-carboxyldeoxycytidine (5-caC) quantitatively in tumorous and non-tumorous regions of GCs; [D2]-5-hmC was used as an internal standard. Expression levels of the genes TET1, TET2, TET3, TDG, IDH1 and IDH2 were measured using a real-time reverse transcription polymerase chain reaction (RT-PCR) and were compared to the clinical attributes of each case. Using HEK293T cells the effects of introducing plasmids containing full-length TET1, TET2, and TET3 and 7 variants of the TET2 catalytic domain were evaluated in terms of their effect on cytosine demethylation. RESULTS: LC-MS/MS showed that 5-hmC was significantly decreased in tumorous portions. 5-mC was also moderately decreased in tumors, while 5-fC and 5-caC were barely detectable. The expressions of TET1, TET2, TET3, TDG and IDH2, but not IDH1, were notably decreased in GCs, compared with the adjacent non-tumor portion. TET1 expression and the 5-hmC levels determined using LC-MS/MS had a significantly positive correlation and TET1 protein had a greater effect on the increase in 5-hmC than TET2 and TET3 in HEK293T cells. CONCLUSIONS: The loss of 5-hmC and the down-regulation of TET1-3, TDG and IDH2 were found in GCs. The loss of 5-hmC in GCs was mainly correlated with the down-regulation of TET1.

High prevalence of the MYD88 mutation in testicular lymphoma: Immunohistochemical and genetic analyses.

The activating mutation of MYD88 has been identified in diffuse large B-cell lymphoma (DLBCL). We investigated the mutational status and both the gene amplification and protein expression of MYD88 in 23 cases of testicular DLBCL. To detect the MYD88 mutations, we employed the allele-specific PCR and Sanger sequencing. MYD88 gene amplification and protein expression were analyzed by quantitative PCR and by immunohistochemistry, respectively. There were 17 cases of primary testicular DLBCL: 94% (16/17) exhibited a non-Germinal center B-cell (non-GCB) subtype, 82% (14/17) showed the MYD88 L265P, and 65% (11/17) had intense expression of MYD88. When compared with normal lymph nodes, the MYD88 is significantly amplified in primary testicular DLBCL. However, the amplification status showed no correlation with its mutational status or protein expression. Moreover, neither the MYD88 mutational status nor the expression pattern affected overall survival. Six cases were secondary testicular DLBCL with an 83% (5/6) and an 80% (4/5) incidence of the non-GCB subtype and of the MYD88 L265P, respectively. In conclusion, we demonstrated a high prevalence of the non-GCB subtype and the common MYD88 L265P in both primary and secondary testicular DLBCL. Our data suggest that the MYD88 mutation is a fairly consistent genetic feature in testicular DLBCL.

Association between KCNJ6 (GIRK2) gene polymorphism rs2835859 and post-operative analgesia, pain sensitivity, and nicotine dependence.

G-protein-activated inwardly rectifying potassium (GIRK) channels are expressed in many tissues and activated by several Gi/o protein-coupled receptors, such as opioid and dopamine receptors, and thus are known to be involved in the modulation of opioid-induced analgesia, pain, and reward. We focused on a GIRK-channel subunit that plays a pivotal role in the brain, GIRK2, and investigated the contribution of genetic variations of the GIRK2 (KCNJ6) gene to individual differences in the sensitivity to opioid analgesia. In our initial linkage disequilibrium analysis, a total of 27 single-nucleotide polymorphisms (SNPs) were selected within and around the regions of the KCNJ6 gene. Among them, the rs2835859 SNP, for which associations with analgesia and pain have not been previously reported, was selected in the exploratory study as a potent candidate SNP associated with opioid analgesic sensitivity. The results were corroborated in further confirmatory study. Interestingly, this SNP was also found to be associated with sensitivity to both cold and mechanical pain, susceptibility to nicotine dependence, and successful smoking cessation. The results indicate that this SNP could serve as a marker that predicts sensitivity to analgesic and pain and susceptibility to nicotine dependence.

Identification and association study with lung cancer for novel insertion polymorphisms of human endogenous retrovirus.

Sequences of human endogenous retroviruses (HERVs) are members of the long terminal repeat (LTR) retrotransposon family. Although the expression of HERV has long been a topic of investigation, HERV-insertion polymorphisms are not well known, and a genetic association between HERV-insertion polymorphisms and cancer has never been reported. To identify novel HERV loci in the genome from cancer tissues, we carried out the inverse PCR method targeting a conserved LTR region of HML-2, which is the most recently acquired HERV group. Novel two insertions, HML-2_sLTR(1p13.2) and HML-2_sLTR(19q12), were identified as insertionally polymorphic solo LTRs. Furthermore, a significant prevalence of HML-2_sLTR(1p13.2) homozygosity was detected in female never-smoking patients aged 60 years and over who had lung adenocarcinoma [versus the other genotyping; odds ratio (OR): 1.97; 95% confidence interval (CI): 1.01-3.81]. In another cohort consisting of female never-smoking patients with lung adenocarcinoma, a prevalence of HML-2_sLTR(1p13.2) homozygosity tended to be high in patients aged 60 years and over (versus the other genotyping; OR: 2.03; 95% CI: 0.96-4.29), whereas a low prevalence of HML-2_sLTR(1p13.2) homozygosity was detected in patients <60 years old (versus the other genotyping; OR: 0.31; 95% CI: 0.11-0.94). Our results suggest that HML-2_sLTR(1p13.2) is involved with the susceptibility to lung adenocarcinoma in female never-smokers in an age-dependent manner and that other HERV polymorphisms related to human diseases might remain to be identified in the human genome.

Cytological study of 44 cases with solid papillary carcinoma and a systemic review of solid papillary carcinoma and neuroendocrine tumor of the breast.

BACKGROUND: Solid-papillary carcinoma (SPC) of the breast is a rare variant of low-grade in situ and invasive carcinoma but there are only a few of the cytologic studies. METHODS: We examined 44 cases of SPC of the breast to define the cytologic features. We also made a systemic review of reported cases of SPC and neuroendocrine tumor (NET) of the breast. RESULTS: Both of our and the reviewed cases with SPC were very similar in the cytologic finding. It included hypercellularity, highly discohesive clusters, numerous isolated cells, small nuclei, finely granular chromatin of salt-and-pepper appearance, inconspicuous nucleoli, low nuclear-cytoplasmic ratio, and a plasmacytoid appearance. Moreover, SPC and NET had frequently all of these features in common. Capillary vessels structures and mucinous substance were not frequently seen in our and the reviewed cases with SPC. Rosette and pseudorosette were very rare in the cytologic specimen. The immunocytochemistry with our 9 cases with SPC indicated diffuse positivity for chromogranin A and/or synaptophysin. CONCLUSION: Many cytologic features are frequently shared by SPC and NET of the breast. However, the vascular structure may not be a precise criterion for SPC. Rosette and pseudorosette are rarely helpful for the cytologic diagnosis.

DNA methylation status of SHATI/NAT8L promoter in the blood of cigarette smokers.

AIMS: Cigarette smoking is a preventable risk factor for various diseases such as cancer, ischemic stroke, cardiac stroke, and chronic obstructive pulmonary disease. Smoking cessation is of great importance not only for individual smokers but also for social health. Regarding current cessation therapies, the effectiveness of nicotine replacement is limited, and the cost of varenicline medication is considerable. Thus, a method for screening smokers who are responsive to cessation therapy based on the therapeutic effectiveness is required. Peripheral biomarkers reflecting smoking dependence status are necessary to establish a method for achieving effective cessation therapy. METHODS: Methylation status of smokers' blood DNA was evaluated focusing on SHATI/NAT8L, an addiction-related gene. Eight CpG sites in SHATI/NAT8L were quantified by pyrosequencing. RESULTS: There was no difference in the methylation status of this gene between smokers (n = 129) and non-smokers (n = 129) at all CpG sites. No correlations between the methylation status of SHATI/NAT8L and indicators of smoking dependence were found. CONCLUSIONS: Although the present study found no significance in the DNA methylation of SHATI/NAT8L among smokers, the exploration of predictable peripheral biomarkers for the effectiveness of smoking cessation therapy is required.

Diagnostic Utility of STAT6 and pSTAT6 Immunohistochemistry for Distinguishing Classic Hodgkin Lymphoma and Peripheral T-Cell Lymphoma With Hodgkin and Reed-Sternberg-like Cells.

Peripheral T-cell lymphomas (PTCLs), particularly nodal lymphomas of T-follicular helper cell origin, may include Hodgkin/Reed-Sternberg (HRS)-like cells in their microenvironment. These HRS-like cells are morphologically indistinguishable from HRS cells of classic Hodgkin lymphoma (CHL). Therefore, PTCLs with HRS-like cells pose a differential diagnosis vis-à-vis CHL. A previous study reported that, in contrast to HRS cells, programmed death-ligand 1 (PD-L1) expression is rare in HRS-like cells of PTCLs and suggested that PD-L1 immunohistochemistry is useful to differentiate HRS cells and HRS-like cells. In this study, we analyzed 21 patients with PTCL with HRS-like cells and 34 patients with CHL and assessed the diagnostic utility of STAT6, pSTAT6, and pSTAT3 immunohistochemistry in distinguishing HRS cells from HRS-like cells. In addition, we also performed PD-L1 immunohistochemistry to reconfirm its utility in distinguishing the 2 diseases. Compared with HRS cells in CHLs, HRS-like cells in PTCLs showed significantly less positivity for STAT6 (9.6% vs. 70%, P <0.001), pSTAT6 (9.6% vs. 70%, P <0.001), and PD-L1 (9.6% vs. 85%, P <0.001). Thus, we reconfirmed the diagnostic utility of PD-L1 immunohistochemistry in distinguishing CHLs from PTCLs with HRS-like cells. In contrast, both HRS-like and HRS cells were highly associated with pSTAT3 expression, with no significant difference in positive cell frequency (86% vs. 91%, P =0.66). On the basis of these findings, we conclude that, in addition to PD-L1, STAT6 and pSTAT6 immunohistochemistry are helpful diagnostic tools to distinguish CHLs from PTCLs with HRS-like cells.

A functional single nucleotide polymorphism in mucin 1, at chromosome 1q22, determines susceptibility to diffuse-type gastric cancer.

BACKGROUND & AIMS: Two major types of gastric cancer, intestinal and diffuse, develop through distinct mechanisms; the diffuse type is considered to be more influenced by genetic factors, although the mechanism is unknown. Our previous genome-wide association study associated 3 single nucleotide polymorphisms (SNPs) with diffuse-type gastric cancer (DGC); 1 was a functional SNP (rs2294008) in prostate stem cell antigen (PSCA), but the loci of the other 2 were not investigated. METHODS: We performed high-density mapping to explore a linkage disequilibrium status of the 2 SNPs at chromosome 1q22. A DGC case-control study was conducted using DNA from 606 cases and 1264 controls (all Japanese individuals) and validated using DNA from Japanese (304 cases, 1465 controls) and Korean (452 cases, 372 controls) individuals. The effects of SNPs on function were analyzed by reporter assays and analyses of splice variants. RESULTS: A region of a strong linkage disequilibrium with the 2 SNPs contained mucin 1 (MUC1) and other 4 genes and SNPs significantly associated with DGC (rs2070803: P = 4.33 × 10(-13); odds ratio [OR], 1.71 by meta-analysis of the studies on the 3 panels) but not with intestinal-type gastric cancer. Functional studies demonstrated that rs4072037 (P = 1.43 × 10(-11); OR, 1.66 by meta-analysis) in MUC1 affects promoter activity and determines the major splicing variants of MUC1 in the gastric epithelium. Individuals that carry both SNPs rs2294008 in PSCA and rs4072037 in MUC1 have a high risk for developing DGC (OR, 8.38). CONCLUSIONS: MUC1 is the second major DGC susceptibility gene identified. The SNPs rs2070803 and rs4072037 in MUC1 might be used to identify individuals at risk for this type of gastric cancer.

Association between dopamine beta hydroxylase rs5320 polymorphism and smoking behaviour in elderly Japanese.

The dopaminergic brain pathway is involved in many addictive behaviours, hence represents a good candidate in the study of smoking behaviour and nicotine addiction. Dopamine beta hydroxylase (DBH) is an enzyme that catalyses the conversion of dopamine into noradrenaline. This study, the first of its kind, was done to investigate the role of DBH rs5320 polymorphism in smoking behaviour of elderly Japanese. This was done by collecting blood samples from 2521 subjects with various smoking habits to genotype the DBH rs5320 polymorphism. Participants also had to fill out a questionnaire containing questions regarding their lifestyles. Some of the questions were from the Fagerström Test for Nicotine Dependence (FTND) and the Tobacco Dependence Screener (TDS). It was found that male ever-smokers with AA genotype smoked less cigarettes per day than those with GG and AG genotypes. FTND scores were also lowest in male ever-smokers with AA genotype and in female ever-smokers with AG genotype. There was no correlation detected between the TDS scores and any of the genotypes. This study shows that DBH rs5320 polymorphism influences nicotine dependence.

Germline alterations in the CDH1 gene in familial gastric cancer in the Japanese population.

Germline point or small frameshift mutations of the CDH1 (E-cadherin) gene are known to cause familial gastric cancer (FGC), but the frequency of CDH1 mutations is low in Japanese patients with FGC. Because recent studies have reported germline large genomic deletions of CDH1 in European and Canadian patients with FGC, in the present study we examined DNA samples from 13 Japanese patients with FGC to determine whether similar germline changes were present in CDH1 in this population. Using a sequencing analysis, a 1-bp deletion (c.1212delC), leading to the production of a truncated protein (p.Asn405IlefsX12), was found in an FGC family; immunohistochemical analysis revealed the loss of CDH1 protein expression in the tumors in this family. Using a combination of multiplex ligation-dependent probe amplification (MLPA) and RT-PCR analyses, we also found a large genomic deletion (c.164-?_387+?del), leading to the loss of exon 3 and the production of a truncated protein (p.Val55GlyfsX38), in another FGC family. The functional effects of the detected mutations were examined using a slow aggregation assay. Significant impairment of cell-cell adhesion was detected in CHO-K1 cells expressing Ile405fsX12- and Gly55fsX38-type CDH1 compared with cells expressing wild-type CDH1. Our results suggest that the p.Asn405IlefsX12 and p.Val55GlyfsX38 mutations of the CDH1 gene contribute to carcinogenesis in patients with FGC. This is the first report of CDH1 germline truncating mutations in Japanese patients with FGC. Screening for large germline rearrangements should be included in CDH1 genetic testing for FGC.

Mass spectrometric profiling of DNA adducts in the human stomach associated with damage from environmental factors.

BACKGROUND: A comprehensive understanding of DNA adducts, one of the most plausible origins of cancer mutations, is still elusive, especially in human tissues in clinical settings. Recent technological developments have facilitated the identification of multiple DNA adducts in a single experiment. Only a few attempts toward this "DNA adductome approach" in human tissues have been reported. Geospatial information on DNA adducts in human organs has been scarce. AIM: Mass spectrometry of human gastric mucosal DNA was performed to identify DNA adducts associated with environmental factors. MATERIALS AND METHODS: From 59 subjects who had received gastrectomy for gastric cancer, 306 samples of nontumor tissues and 15 samples of tumors (14 cases) were taken for DNA adductome analysis. Gastric nontumor tissue from autopsies of 7 subjects without gastric cancer (urothelial cancer, hepatocellular carcinoma, lung cancer each; the other four cases were without any cancers) was also investigated. Briefly, DNA was extracted from each sample with antioxidants, digested into nucleosides, separated by liquid chromatography, and then electrospray-ionized. Specific DNA adducts were identified by mass/charge number and column retention time compared to standards. Information on lifestyle factors such as tobacco smoking and alcohol drinking was taken from the clinical records of each subject. RESULTS: Seven DNA adducts, including modified bases, C5-methyl-2'-deoxycytidine, 2'-deoxyinosine, C5-hydroxymethyl-2'-deoxycytidine, N6-methyl-2'-deoxyadenosine, 1,N6-etheno-2'-deoxyadenosine, N6-hydroxymethyl-2'-deoxyadenosine, and C8-oxo-2'-deoxyguanosine, were identified in the human stomach and characterized. Intraindividual differences according to the multiple sites of these adducts were noted but were less substantial than interindividual differences. N6-hydroxymethyl-2'-deoxyadenosine was identified in the human stomach for the first time. The amount of C5-hydroxymethyl-2'-deoxycytidine was higher in the stomachs of subjects without gastric cancer than in the nontumor and tumor portions of the stomach in gastric cancer patients. Higher levels of 1,N6-etheno-2'-deoxyadenosine were detected in the subjects who reported both smoking and drinking than in those without these habits. These DNA adducts showed considerable correlations with each other. CONCLUSIONS: We characterized 7 DNA adducts in the nontumor portion of the human stomach in both gastric cancer subjects and nongastric cancer subjects. A reduction in C5-hydroxymethyl-dC even in the nontumor mucosa of patients with gastric cancer was observed. Smoking and drinking habits significantly influenced the quantity of one of the lipid peroxidation-derived adducts, etheno-dA. A more expansive DNA adductome profile would provide a comprehensive understanding of the origin of human cancer in the future.

Geospatial Assessments of DNA Adducts in the Human Stomach: A Model of Field Cancerization.

BACKGROUND: Field cancerization is a popular concept regarding where cancer cells arise in a plane, such as the opened-up gastrointestinal mucosa. The geospatial distribution of DNA adducts, some of which are believed to initiate mutation, may be a clue to understanding the landscape of the preferred occurrence of gastric cancer in the human stomach, such that the occurrence is much more frequent in the lesser curvature than in the greater curvature. METHODS: Seven DNA adducts, C5-methyl-2'-deoxycytidine, 2'-deoxyinosine, C5-hydroxymethyl-2'-deoxycytidine, N6-methyl-2'-deoxyadenosine, 1,N6-etheno-2'-deoxyadenosine, N6-hydroxymethyl-2'-deoxyadenosine, and C8-oxo-2'-deoxyguanosine, from different points and zones of the human stomach were semi quantitatively measured by liquid chromatography/tandem mass spectrometry. The differences in the quantity of these DNA adducts from the lesser and greater curvature, the upper, middle and lower third zones, the anterior and posterior wall of the stomach, and the mucosae distant from and near the tumor were compared to determine whether the location preference of cancer in the stomach could be explained by the distribution of these DNA adducts. Comparisons were conducted considering the tumor locations and operation methods. CONCLUSIONS: Regarding the DNA adducts investigated, significant differences in quantities and locations in the whole stomach were not noted; thus, these DNA adducts do not explain the preferential occurrence of cancer in particular locations of the human stomach.

Association between neuropeptide Y receptor 2 polymorphism and the smoking behavior of elderly Japanese.

Molecular heterogeneity of neuropeptide Y (NPY) and its three receptors (1, 2 and 5) has recently been discovered. NPY2R polymorphisms have been shown to be related to cocaine and alcohol dependence in European Americans. To test our hypothesis that these polymorphisms influence the smoking behavior of Japanese population, we investigated the prevalence of the rs4425326 and rs6857715 polymorphisms, which have been suggested to be related to alcohol dependence in European Americans, in 2517 Japanese elderly subjects for whom information on smoking behaviors was available. The prevalence of current smokers was greater among Japanese men having the rs4425326 C allele than ex-smokers. Among the ever-smokers, the Fagerström Test for Nicotine Dependence scores were higher in men having the rs4425326 homozygous T allelotype, and the numbers of cigarettes smoked per day were also significantly higher in the male smokers having the TT genotype. No correlations between the Tobacco Dependence Screener scores and any genotypes were detected. These results suggest that rs4425326 polymorphism may be related to smoking behavior in the Japanese elderly population. This study for the first time suggests NPY2R genotype as a possible genetic factor in nicotine dependence.

Fluorescence in situ hybridization analysis with a tissue microarray: 'FISH and chips' analysis of pathology archives.

Practicing pathologists expect major somatic genetic changes in cancers, because the morphological deviations in the cancers they diagnose are so great that the somatic genetic changes to direct these phenotypes of tumors are supposed to be correspondingly tremendous. Several lines of evidence, especially lines generated by high-throughput genomic sequencing and genome-wide analyses of cancer DNAs are verifying their preoccupations. This article reviews a comprehensive morphological approach to pathology archives that consists of fluorescence in situ hybridization with bacterial artificial chromosome (BAC) probes and screening with tissue microarrays to detect structural changes in chromosomes (copy number alterations and rearrangements) in specimens of human solid tumors. The potential of this approach in the attempt to provide individually tailored medical practice, especially in terms of cancer therapy, is discussed.

Absence of germline mono-allelic promoter hypermethylation of the CDH1 gene in gastric cancer patients.

BACKGROUND: Germline mono-allelic promoter hypermethylation of the MLH1 or MSH2 gene in families with hereditary nonpolyposis colorectal cancer has recently been reported. The purpose of this study was to evaluate if germline promoter hypermethylation of the tumor suppressor gene CDH1 (E-cadherin) might cause predisposition to gastric cancer. METHODS: We prepared two groups of samples, a group of blood samples from 22 patients with familial gastric cancer or early-onset gastric cancer selected from among 39 patients, and a group of non-cancerous gastric tissue samples from 18 patients with sporadic gastric cancer showing loss of CDH1 expression selected from among 159 patients. We then investigated the allele-specific methylation status of the CDH1 promoter by bisulfite sequencing of multiple clones. RESULTS: Although there was a difference between the methylation level of the two alleles in some samples, there was no mono-allelic promoter hypermethylation in any of the samples. CONCLUSION: These results suggest that germline mono-allelic hypermethylation of the CDH1 promoter is not a major predisposing factor for gastric cancer.