Severe induction of aberrant DNA methylation by nodular gastritis in adults.

BACKGROUND: Nodular gastritis (NG) is characterized by marked antral lymphoid follicle formation, and is a strong risk factor for diffuse-type gastric cancer in adults. However, it is unknown whether aberrant DNA methylation, which is induced by atrophic gastritis (AG) and is a risk for gastric cancer, is induced by NG. Here, we analyzed methylation induction by NG. METHODS: Gastric mucosal samples were obtained from non-cancerous antral tissues of 16 NG and 20 AG patients with gastric cancer and 5 NG and 6 AG patients without, all age- and gender-matched. Genome-wide methylation analysis and expression analysis were conducted by a BeadChip array and RNA-sequencing, respectively. RESULTS: Clustering analysis of non-cancerous antral tissues of NG and AG patients with gastric cancer was conducted using methylation levels of 585 promoter CpG islands (CGIs) of methylation-resistant genes, and a large fraction of NG samples formed a cluster with strong methylation induction. Promoter CGIs of CDH1 and DAPK1 tumor-suppressor genes were more methylated in NG than in AG. Notably, methylation levels of these genes were also higher in the antrum of NG patients without cancer. Genes related to lymphoid follicle formation, such as CXCL13/CXCR5 and CXCL12/CXCR4, had higher expression in NG, and genes involved in DNA demethylation TET2 and IDH1, had only half the expression in NG. CONCLUSIONS: Severe aberrant methylation, involving multiple tumor-suppressor genes, was induced in the gastric antrum and body of patients with NG, in accordance with their high gastric cancer risk.

Marked intestinal trans-differentiation by autoimmune gastritis along with ectopic pancreatic and pulmonary trans-differentiation.

BACKGROUND: Autoimmune gastritis (AIG) is a prevalent chronic inflammatory disease with oncogenic potential that causes destruction of parietal cells and severe mucosal atrophy. We aimed to explore the distinctive gene expression profiles, activated signaling pathways, and their underlying mechanisms. METHODS: A comprehensive gene expression analysis was conducted using biopsy specimens from AIG, Helicobacter pylori-associated gastritis (HPG), and non-inflammatory normal stomachs. Gastric cancer cell lines were cultured under acidic (pH 6.5) conditions to evaluate changes in gene expression. RESULTS: Gastric mucosa with AIG had a unique gene expression profile compared with that with HPG and normal mucosa, such as extensively low expression of ATP4A and high expression of GAST and PAPPA2, which are involved in neuroendocrine tumorigenesis. Additionally, the mucosa with AIG and HPG showed the downregulation of stomach-specific genes and upregulation of small intestine-specific genes; however, intestinal trans-differentiation was much more prominent in AIG samples, likely in a CDX-dependent manner. Furthermore, AIG induced ectopic expression of pancreatic digestion-related genes, PNLIP, CEL, CTRB1, and CTRC; and a master regulator gene of the lung, NKX2-1/TTF1 with alveolar fluid secretion-related genes, SFTPB and SFTPC. Mechanistically, acidic conditions led to the downregulation of master regulator and stemness control genes of small intestine, suggesting that increased environmental pH may cause abnormal intestinal differentiation in the stomach. CONCLUSIONS: AIG induces diverse trans-differentiation in the gastric mucosa, characterized by the transactivation of genes specific to the small intestine, pancreas, and lung. Increased environmental pH owing to AIG may cause abnormal differentiation of the gastric mucosa.

Precancerous nature of intestinal metaplasia with increased chance of conversion and accelerated DNA methylation.

OBJECTIVE: The presence of intestinal metaplasia (IM) is a risk factor for gastric cancer. However, it is still controversial whether IM itself is precancerous or paracancerous. Here, we aimed to explore the precancerous nature of IM by analysing epigenetic alterations. DESIGN: Genome-wide DNA methylation analysis was conducted by EPIC BeadArray using IM crypts isolated by Alcian blue staining. Chromatin immunoprecipitation sequencing for H3K27ac and single-cell assay for transposase-accessible chromatin by sequencing were conducted using IM mucosa. NOS2 was induced using Tet-on gene expression system in normal cells. RESULTS: IM crypts had a methylation profile unique from non-IM crypts, showing extensive DNA hypermethylation in promoter CpG islands, including those of tumour-suppressor genes. Also, the IM-specific methylation profile, namely epigenetic footprint, was present in a fraction of gastric cancers with a higher frequency than expected, and suggested to be associated with good overall survival. IM organoids had remarkably high NOS2 expression, and NOS2 induction in normal cells led to accelerated induction of aberrant DNA methylation, namely epigenetic instability, by increasing DNA methyltransferase activity. IM mucosa showed dynamic enhancer reprogramming, including the regions involved in higher NOS2 expression. NOS2 had open chromatin in IM cells but not in gastric cells, and IM cells had frequent closed chromatin of tumour-suppressor genes, indicating their methylation-silencing. NOS2 expression in IM-derived organoids was upregulated by interleukin-17A, a cytokine secreted by extracellular bacterial infection. CONCLUSIONS: IM cells were considered to have a precancerous nature potentially with an increased chance of converting into cancer cells, and an accelerated DNA methylation induction due to abnormal NOS2 expression.

Mouse methylation profiles for leukocyte cell types, and estimation of leukocyte fractions in inflamed gastrointestinal DNA samples.

Precise analysis of tissue DNA and RNA samples is often hampered by contaminating non-target cells whose amounts are highly variable. DNA methylation profiles are specific to cell types, and can be utilized for assessment of the fraction of such contaminating non-target cells. Here, we aimed 1) to identify methylation profiles specific to multiple types of mouse leukocytes, and 2) to estimate the fraction of leukocytes infiltrating inflamed tissues using DNA samples. First, genome-wide DNA methylation analysis was conducted for three myeloid-lineage cells and four lymphoid-lineage cells isolated by fluorescence-activated cell sorting after magnetic-activated cell sorting from leukocytes in the spleen. Clustering analysis using CpG sites within enhancers separated the three myeloid-lineage cells and four lymphoid-lineage cells while that using promoter CpG islands (TSS200CGIs) did not. Among the 266,108 CpG sites analyzed, one CpG site was specifically hypermethylated (ß value ≥ 0.7) in B cells, and four, seven, 183, and 34 CpG sites were specifically hypomethylated (ß value < 0.2) in CD4+ T cells, CD8+ T cells, B cells, and NK cells, respectively. Importantly, cell type-specific hypomethylated CpG sites were located at genes involved in cell type-specific biological functions. Then, marker CpG sites to estimate the leukocyte fraction in a tissue with leukocyte infiltration were selected, and an estimation algorithm was established. The fractions of infiltrating leukocytes were estimated to be 1.6-12.4% in the stomach (n = 10) with Helicobacter pylori-induced inflammation and 1.5-4.3% in the colon with dextran sulfate sodium-induced colitis (n = 4), and the fractions were highly correlated with those estimated histologically using Cd45-stained tissue sections [R = 0.811 (p = 0.004)]. These results showed that mouse methylation profiles at CpG sites within enhancers reflected leukocyte cell lineages, and the use of marker CpG sites successfully estimated the leukocyte fraction in inflamed gastric and colon tissues.

HSD17B4 methylation enhances glucose dependence of BT-474 breast cancer cells and increases lapatinib sensitivity.

PURPOSE: HER2-positive breast cancer has a high chance of achieving pathological complete response when HSD17B4, responsible for peroxisomal ß-oxidation of very long-chain fatty acids (VLCFA) and estradiol, is methylation-silenced. Here, we aimed to identify the underlying molecular mechanism. METHODS: Using a HER2-positive breast cancer cell line, BT-474, control and knock-out (KO) clones were obtained. Metabolic characteristics were analyzed using a Seahorse Flux analyzer. RESULTS: HSD17B4 KO suppressed cellular proliferation, and enhanced sensitivity to lapatinib approximately tenfold. The KO led to accumulation of VLCFA and a decrease of polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA) and arachidonic acid. HSD17B4 KO increased Akt phosphorylation, possibly via decreased DHA, and genes involved in oxidative phosphorylation (OxPhos) and electron transport chain (ETC) were upregulated. Increased mitochondrial ATP production in the KO cells was confirmed by extracellular flux analyzer. Increased OxPhos led to severe dependence of the KO cells on pyruvate from glycolysis. Suppression of glycolysis by lapatinib led to severe delayed suppression of OxPhos in KO cells. CONCLUSION: HSD17B4 KO in BT-474 cells caused a decrease of PUFAs, increased Akt phosphorylation, enhanced glucose dependence of OxPhos, and increased sensitivity to inhibition of HER2, upstream of Akt. This mechanism may be applicable to other HER2-positive glucose-dependent breast cancer cells with HSD17B4 silencing.

The methylation level of a single cancer risk marker gene reflects methylation burden in gastric mucosa.

BACKGROUND: Gastric cancer risk can be accurately predicted by measuring the methylation level of a single marker gene in gastric mucosa. However, the mechanism is still uncertain. We hypothesized that the methylation level measured reflects methylation alterations in the entire genome (methylation burden), induced by Helicobacter pylori (H. pylori) infection, and thus cancer risk. METHODS: Gastric mucosa of 15 healthy volunteers without H. pylori infection (G1), 98 people with atrophic gastritis (G2), and 133 patients with gastric cancer (G3) after H. pylori eradication were collected. Methylation burden of an individual was obtained by microarray analysis as an inverse of the correlation coefficient between the methylation levels of 265,552 genomic regions in the person's gastric mucosa and those in an entirely healthy mucosa. RESULTS: The methylation burden significantly increased in the order of G1 (n = 4), G2 (n = 18), and G3 (n = 19) and was well correlated with the methylation level of a single marker gene (r = 0.91 for miR124a-3). The average methylation levels of nine driver genes tended to increase according to the risk levels (P = 0.08 between G2 vs G3) and was also correlated with the methylation level of a single marker gene (r = 0.94). Analysis of more samples (14 G1, 97 G2, and 131 G3 samples) yielded significant increases of the average methylation levels between risk groups. CONCLUSIONS: The methylation level of a single marker gene reflects the methylation burden, which includes driver gene methylation, and thus accurately predicts cancer risk.

The distribution of submerged macrophytes in response to intense solar radiation and salinity reveals hydrogen peroxide as an abiotic stress indicator.

The feasible condition for submerged macrophyte growth is hard to understand as many environmental factors contribute to establishing macrophyte distribution with different intensities generating excess reactive oxygen species (ROS). Among various kinds of ROS, hydrogen peroxide (H2O2) is relatively stable and can be measured accurately. Thus, for the quantification of submerged macrophyte species, H2O2 can be used to evaluate their distribution in a lake. Submerged macrophytes, such as Potamogeton anguillanus, were abundant in Lake Shinji. The largest biomass distribution was around 1.35 m deep, under low solar radiation intensity, and nearly no biomass was found less than 0.3 m deep, where solar radiation was high. Tissue H2O2 concentrations varied in response to the diurnal photosynthetically active radiation (PAR) intensity, which was followed by antioxidant activities, though slightly delayed. Laboratory experiments were conducted with different PAR intensities or salinity concentrations. A stable level of H2O2 was maintained up to about 200 µmol m-2 s-1 of PAR for 30 days, followed by a gradual increase as PAR increased. The H2O2 concentration increased with higher salinity. A change in Chlorophyll a (Chl-a) concentration is associated with an altering H2O2 concentration, following a unique negative relationship with H2O2 concentration. If H2O2 exceeded 45 µmol/gFW, the homeostasis collapsed, and H2O2 and Chl-a significantly declined afterward. The above findings indicate that H2O2 has a negative effect on the physiological condition of the plant. The increase in H2O2 concentration was prevented by antioxidant activities, which elevated with increasing H2O2 concentration.

Trends in proton pump inhibitor use, reflux esophagitis, and various upper gastrointestinal symptoms from 2010 to 2019 in Japan.

The increasing usage of proton pump inhibitors (PPIs) has been reported worldwide, but information on PPI use in East Asia is inadequate. This study aimed to examine the trends in PPI use in Japan, along with the changes in histamine H2 receptor antagonist (H2RA) use, disease rate of reflux esophagitis, and the prevalence of upper gastrointestinal symptoms. We analyzed 217,712 healthy subjects (127,607 men and 90,105 women; 51.4 ± 9.7 years old) participating in the health check program from 2010 to 2019. Various upper gastrointestinal symptoms were evaluated using the frequency scale for the symptoms of gastroesophageal reflux disease (FSSG) questionnaire. Reflux esophagitis was diagnosed by esophageal erosion using the Los Angeles classification grades A, B, C, and D. From 2010 to 2019, the percentage of PPI users increased markedly from approximately 1.8% to 5.3%, whereas that of H2RA users decreased gradually from approximately 2.5% to 1.9%. The use of all classical types of PPIs (omeprazole, lansoprazole, rabeprazole, and esomerazole) and a new type of PPI, a potassium-competitive acid blocker (vonoprazan), greatly increased during the 10 years. An upward trend in the prevalence of reflux esophagitis was observed from 2010 to 2015, but not from 2016 to 2019, indicating that the monotonic rising prevalence of reflux disease stopped in the middle of the 2010s in Japan. In contrast, various upper gastrointestinal symptoms significantly improved between 2010 and 2019. All 12 FSSG symptoms of PPI users were significantly worse than those of non-PPI users, suggesting that PPIs still cannot completely control upper gastrointestinal symptoms. In conclusion, this study revealed a significant increase in PPI use and a slight decrease in H2RA use from 2010 to 2019. Despite a plateau in the prevalence of reflux esophagitis and considerable improvement in various upper gastrointestinal symptoms, PPI use has continued to increase in Japan.

Transcriptome of sessile serrated adenoma/polyps is associated with MSI-high colorectal cancer and decreased expression of CDX2.

The objective of this study was to elucidate the molecular background of sessile serrated adenoma/polyp (SSA/P) endoscopically resected with comprehensive gene expression analysis. Gene expression profiling was performed for 10 tumor-normal pairs of SSA/P. Cluster analysis, gene set enrichment analysis (GSEA), and consensus molecular subtype (CMS) classification of colorectal cancer (CRC) were applied to our transcriptome analysis. Unsupervised cluster analysis showed that the gene expression profile of SSA/Ps is different from that of adjacent normal epithelial cells, even in the very early stage of tumorigenesis. According to the CMS classification, our microarray data indicated that SSA/Ps were classified as CMS1. GSEA demonstrated a strong association between SSA/P and microsatellite instability-high (MSI-H) CRC (p < 10-5 ). Transcriptome analysis of five MSI-related genes (MSH2, MSH6, MLH1, PMS1, and PMS2) and five CRC-related genes (BRAF, KRAS, APC, TP53, and CDX2) showed that CDX2 expression was most severely decreased in SSA/P. Immunohistochemical staining confirmed that CDX2 protein was reduced compared with the surrounding mucosa. Direct sequencing of the BRAF gene showed that the BRAF V600E mutation was detected in only nine of 36 cases. In a mouse model, BRAF, APC, or CDX2 deficiency indicated that the gene expression pattern with loss of CDX2 is more similar to our SSA/Ps compared with those induced by BRAF or APC mutation. Transcriptome analysis of SSA/Ps showed characteristic gene expression with a strong resemblance to MSI-H CRC. Downregulation of CDX2 expression is an essential molecular mechanism involved in the initial stage of SSA/P tumorigenesis. (UMIN000027365).

Autoimmune gastritis induces aberrant DNA methylation reflecting its carcinogenic potential.

BACKGROUND: Autoimmune gastritis (AIG) is a chronic inflammatory condition in gastric mucosa and is associated with increased cancer risk, though not as high as that by Helicobacter pylori (H. pylori)-associated gastritis (HPG). Although aberrant DNA methylation is induced by HPG and the level correlates with the risk of gastric cancer, DNA methylation induction by AIG is unknown. METHODS: Gastric mucosa samples from the corpus were collected from 12 people with AIG without H. pylori infection, 10 people with HPG, and eight healthy volunteers. Genome-wide DNA methylation analysis was conducted using Infinium Methylation EPIC array. Gene expression was analyzed by quantitative RT-PCR. RESULTS: The AIG samples had extensive aberrant DNA methylation but presented unique methylation profiles against the HPG samples after correction of leucocyte fractions. Comparison between the AIG and HPG samples showed that AIG induced methylation, but less than HPG, in overall CpG sites and also in promoter CpG islands. Promoter CpG islands of tumor-suppressor genes in the pathway of cell cycle, cell adhesion, p53, and WNT were highly methylated in the AIG samples, but more so in the HPG samples. The expression levels of IL1B and IL8, secreted by macrophage, were significantly lower in the AIG samples than in the HPG samples, suggesting that a difference in inflammatory response affected the degree and patterns of aberrant DNA methylation. CONCLUSIONS: AIG induced aberrant DNA methylation in gastric mucosa. However, the degree of DNA methylation was less than that by HPG, which reflected carcinogenic risk.

Beneficial screening of Fabry disease in patients with hypohidrosis.

Fabry disease (FD), which is a lysosomal storage disease resulting from a deficiency of α-galactosidase A, leads to the accumulation of globotriaosylceramide in various tissues and multiorgan impairment. Early diagnosis is important to improve long-term prognosis. Early clinical manifestations of FD include neuropathic pain, vascular skin lesions, and sweating abnormalities. Hypohidorosis is one of the clinical findings in the early stage of FD. However, there have been no studies on prospective screening of FD in patients with definitive diagnosis of hypohidrosis. We examined α-galactosidase A activity in white blood cells in 17 (one female and 16 male) patients with generalized hypohidorosis. Among 17 patients, one male patient (approximately 5.8%) had significantly reduced α-galactosidase A activity. He presented with a history of hypohidrosis with heat intolerance and neuropathic tingling pain in a warm environment from 6 years ago. He had a few angiokeratoma on the trunk and extremities. Ultrastructural examination of skin biopsy from the angiokeratoma revealed lamellar inclusions in endothelial cells. Kidney biopsy revealed swollen podocytes and Gb3 deposition in the glomerulus, and urinalysis revealed mulberry bodies. He was finally diagnosed with FD and started on enzyme replacement therapy with agalsidase alpha in the early stage. In addition, his family screening led to find the patients of four additional FD. Screening for FD in patients with hypohidrosis may lead to efficient early detection of FD.

Clinicopathological features and prognosis of developed gastric cancer based on the diagnosis of mucosal atrophy and enlarged folds of stomach by double-contrast upper gastrointestinal barium X-ray radiography.

BACKGROUND: Mucosal atrophy and enlarged folds of stomach by double-contrast upper gastrointestinal barium X-ray radiography (UGI-XR) are two major features of Helicobacter pylori-induced chronic gastritis. These were previously shown to be risk indicators of gastric cancer, but their predictability for clinicopathological characters of developed gastric cancer is unelucidated. In addition, evidence for decreasing the mortality of gastric cancer by appropriate follow-up of UGI screening is needed. METHODS: The 5134 generally healthy UGI-XR examinees, who underwent follow-up UGI-XR or upper gastrointestinal endoscopy (UGI-ES) more than once, were prospectively observed for 10 years. RESULTS: At the beginning of follow-up, 1515 (29.5%) had mucosal atrophy and 990 (19.5%) had enlarged folds. For the serum anti-H. pylori IgG, 1301 (25.3%) were positive, 177 (3.4%) were possibly positive, and 3656 (71.2%) were negative. During the 10-year observation period, gastric cancer developed in 15 subjects, among which 13 had mucosal atrophy and 10 had enlarged folds. These two features were expectedly useful indicators for gastric cancer incidence, but they showed no significant association with tumor stage or histological type of developed cancer. Only one of the 5134 subjects died of gastric cancer during 10 years, which was significantly lower than the predicted number of gastric cancer death (6.78 for 10 years) according to the mortality rate in Japan. CONCLUSIONS: Neither mucosal atrophy nor enlarged folds of stomach showed a significant association with clinicopathological features of developed gastric tumors. Appropriate follow-up of cancer screening by UGI-XR or UGI-ES can reduce the risk of gastric cancer-related death.

The natural history of sporadic non-ampullary duodenal epithelial tumors: Can we wait and see?

Objectives: The natural history of sporadic non-ampullary duodenal epithelial tumors (SNADETs) is poorly documented. The aim of this study was to evaluate the history of SNADETs in patients where immediate resection could not be performed. Methods: This is a single-center retrospective study of 86 consecutive cases of SNADETs who did not undergo immediate resection and were followed-up with upper gastrointestinal endoscopy for more than 6 months. Results: During a follow-up period of 36.8 (6.0-613.0) months, macroscopic progression was admitted in eight (9.3%). Of these, the final histology in four was adenocarcinoma, and three cases demonstrated submucosal invasion. Rates of macroscopic progression at 150 months after detection were 11.1%, 16.7%, and 30.0% for SNADETs <5 mm, <10 mm, and ≥10 mm, respectively. Conclusion: The overall risk of SNADETs progressing to invasive cancer is low. However, changes in macroscopic size or shape of SNADETs signify a high risk of progression to invasive cancer.

Nuclear staining of claudin-18 is a new immunohistochemical marker for diagnosing intramucosal well-differentiated gastric adenocarcinoma.

Diagnosis of gastric adenocarcinoma using small biopsy samples is occasionally difficult. Various markers have been employed for improving the diagnostic accuracy, but there remains room for improvement. A total of 129 endoscopically biopsied samples were studied, consisting of 104 intramucosal tubular adenocarcinomas, 24 non-cancerous lesions and one cancer sample originally suspected of non-cancer but revised as cancer after immunostaining. We evaluated the association between histopathology and immunohistochemical expression of MUC1, HER2, p53, CEA, E-cadherin, ß-catenin and claudin-18. Regarding ß-catenin and claudin-18, not only membranous expression (ß-catenin(M) and claudin-18(M)) but also nuclear expression (ß-catenin(N) and claudin-18(N)) were analyzed. When subtyped with mucin core protein expression, the gastric-type cancers dominantly expressed claudin-18(M), while claudin-18(N) was significantly encountered in intestinal- and mixed-types. Expression of MUC1 (P = 0.0010), HER2 (P = 0.0173), p53 (P = 0.0002), CEA (P = 0.0019) and claudin-18(N) (P < 0.0001) revealed significant correlation with gastric cancers. Negative correlation of claudin-18(M) (P = 0.0125) was also noted. MUC1 and p53 were negative in non-cancer lesions. The non-cancer group exceptionally expressed HER2 and ß-catenin(N). Membranous expression of E-cadherin was consistent in both groups. Logistic regression analysis showed that MUC1 (P = 0.0086), p53 (P = 0.0031), claudin-18(M) (P = 0.0158) and claudin-18(N) (P = 0.0190) were independently associated with gastric cancers. Nuclear expression of claudin-18 should be the novel diagnostic marker for gastric cancer.

The association of Helicobacter pylori infection with serum lipid profiles: An evaluation based on a combination of meta-analysis and a propensity score-based observational approach.

BACKGROUND: Several previous studies have suggested that Helicobacter pylori (H. pylori) infection affects the serum lipid profile. However, it remains controversial and the mechanism has not been elucidated. The purpose of this study is to use an epidemiological perspective to evaluate the association between H. pylori infection and the serum lipid profile. METHODS: Multivariate analysis was performed using the data of serum lipid profile, infection status of H. pylori, fitness/lifestyle habits, and various subjects' characteristics which were derived from the 15,679 generally healthy individuals in Japan. The average treatment effects (ATEs) of H. pylori infection on the serum lipid profile were estimated using augmented inverse probability weighting (AIPW). A meta-analysis was also performed using the 27 studies worldwide in which the status of H. pylori infection and at least one serum examination value (high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), or triglyceride (TG)) were described. RESULTS: The ATEs determined with AIPW showed that H. pylori infection has significant positive effects on LDL-C and TC (ATE (95% confidence interval [95%CI]) = 3.4 (2.36-4.49) and 1.7 (0.58-2.88), respectively) but has significant negative effects on HDL-C and TG (ATE (95%CI) = -1.2 (-1.74 to -0.72) and -3.5 (-5.92 to -1.06), respectively). The meta-analysis to estimate the association between H. pylori infection and the serum lipid profile revealed that H. pylori infection is positively associated with LDL-C, TC, and TG (standardized mean difference [SMD] (95%CI) = 0.11 (0.09-0.12), 0.09 (0.07-0.10) and 0.06 (0.05-0.08), respectively) and negatively associated with HDL-C (SMD = -0.13 (-0.14 to -0.12)). CONCLUSION: Both our multivariate analyses and meta-analysis showed that H. pylori infection significantly affects the serum lipid profile, which might lead to various dyslipidemia-induced severe diseases like coronary thrombosis or cerebral infarction.

Tandem repeats of the 5' flanking region of human MUC5AC have a role as a novel enhancer in MUC5AC gene expression.

MUC5AC is a well-known gastric differentiation marker, which has been frequently used for the classification of stomach cancer. However, the molecular mechanism of regulation of MUC5AC expression remains to be elucidated. In previous studies, we have shown that Gli regulated MUC5AC transcription through the Gli-binding motif in the 5' region of MUC5AC. Gli played important roles, but independently was not sufficient for MUC5AC expression. In this study, we analyzed a 4010 bp fragment of the 5'-flanking promoter region of the human MUC5AC gene by luciferase assay, and found a novel distal enhancer region located between -1434 bp to -3000 bp upstream from the first ATG initiation codon. This region is composed of repetitive DNA sequences 5'-TCACTCAC-3'. The strength of enhancer activities depended on the length of the repetitive region. The tandem repeats are conserved among primates, but not in other mammals. The tandem repeat regions enhanced promoter activities not only of MUC5AC but also of other genes. The enhancer effect of the tandem repeat regions was maintained even when inverted. ChIP analysis revealed that H3K9me3 binds to the tandem repeat regions. Together, our results suggest that the tandem repeat region in the MUC5AC promoter has the potential to act as a strong enhancer, and H3K9me3 may contribute to histone modifications of this region.

Ginnalin B induces differentiation markers and modulates the proliferation/differentiation balance via the upregulation of NOTCH1 in human epidermal keratinocytes.

The red maple and sugar maple (Acer rubrum and A. saccharum, respectively) contain acertannins (ginnalins and maplexins), galloylated derivatives of 1,5-anhydro-d-glucitol (1,5-AG, 1). These compounds have a variety of potential medicinal properties and we have shown that some of them promote the expression of ceramide synthase 3. We now report on the beneficial effects of ginnalin B, (6-O-galloyl-1,5-AG, 5), leading to acceleration of skin metabolism and reduction of the turnover time. Ginnalin B dose-dependently increased the relative amount of keratin 10, keratin 1, and filaggrin gene, with maximal increase of 1.7-, 2.9, and 5.2-fold at 100 µM, respectively. The validation study showed that it had superior capacity to induce multiple stages of keratinocyte differentiation and significantly elevated the immunostaining site of keratin 10 and filaggrin in a 3-dimensional cultured human skin model, by 1.2 and 2.8-fold, respectively. Furthermore, ginnalin B caused the arrest of proliferation at the G0/G1 phase but it did not induce apoptotic cell death in normal human keratinocytes. Molecular studies revealed that ginnalin B up-regulated the levels of NOTCH1 and a concomitant increase p21 expression. Ginnalin B, therefore, represents a new class of promising functional and medical cosmetic compound and it could contribute to the maintenance of homeostasis of the epidermis.

Detection of gastritis by a deep convolutional neural network from double-contrast upper gastrointestinal barium X-ray radiography.

BACKGROUND: Deep learning has become a new trend of image recognition tasks in the field of medicine. We developed an automated gastritis detection system using double-contrast upper gastrointestinal barium X-ray radiography. METHODS: A total of 6520 gastric X-ray images obtained from 815 subjects were analyzed. We designed a deep convolutional neural network (DCNN)-based gastritis detection scheme and evaluated the effectiveness of our method. The detection performance of our method was compared with that of ABC (D) stratification. RESULTS: Sensitivity, specificity, and harmonic mean of sensitivity and specificity of our method were 0.962, 0.983, and 0.972, respectively, and those of ABC (D) stratification were 0.925, 0.998, and 0.960, respectively. Although there were 18 false negative cases in ABC (D) stratification, 14 of those 18 cases were correctly classified into the positive group by our method. CONCLUSIONS: Deep learning techniques may be effective for evaluation of gastritis/non-gastritis. Collaborative use of DCNN-based gastritis detection systems and ABC (D) stratification will provide more reliable gastric cancer risk information.

Identification of marker genes and pathways specific to precancerous duodenal adenomas and early stage adenocarcinomas.

BACKGROUND: The mechanism behind the pathogenesis and carcinogenesis of these neoplasms is not fully understood. The objective of this study was to identify genetic markers and pathways specific to precancerous duodenal adenomas and early stage adenocarcinomas through gene expression analysis. METHODS: Gene expression profiling was performed in 4 pairs of duodenal adenoma/adenocarcinomas and corresponding matched normal tissue. Genes with consistent expression differences were identified and confirmed in 7 independent pairs. Gene set enrichment analysis (GSEA) was performed to characterize gene expression profiles of duodenal adenoma/adenocarcinomas, together with immunohistochemical staining of candidate oncogenic genes. RESULTS: 626 probes consistently demonstrated over a twofold expression difference between tumor-normal pairs. Reverse transcriptase polymerase chain reaction of genes with the most prominent difference in expression between tumors and normal mucosa (KLK7, KLK6, CEMIP, MMP7, KRT17, LGR5, G6PC, S100G, APOA1) validated the results of gene expression analysis. GSEA demonstrated a strong association between duodenal adenoma/adenocarcinomas with colorectal adenomas (p < 10-5) and gene expression patterns seen after APC gene knockout (p < 10-5), suggesting that the Wnt/ß-catenin pathway plays a crucial role in the carcinogenesis of these neoplasms. Immunohistochemical staining of an independent group of duodenal adenomas confirmed over-accumulation of ß-catenin in 80.0% (16/20). CONCLUSIONS: Precancerous duodenal adenomas and early stage adenocarcinomas demonstrate gene expression characteristics with a strong resemblance to colorectal adenomas. The results of this study strongly suggest that upregulation of the Wnt/ß-catenin pathway is the major factor involved in the initial stages of the carcinogenesis of duodenal adenocarcinomas.

Manganese-mediated immobilization of arsenic by calcifying macro-algae, Chara braunii.

The restoration capability of charophyte Chara braunii was studied in arsenic-polluted water in the context of biogenic calcium and manganese depositions on the plant. In addition to calcite encrustation, formation of craterlike shape deposits of manganese oxides (MnOx) with diameters of 5-10 µm was detected on the cell walls of the plants grown in Mn-rich media. Relative proportions of arsenic taken up by the plant biomass to those incorporated into the calcium and manganese biominerals were determined using a modified sequential chemical extraction method. The mean total arsenic recovery from water reached its highest value at 375 mg kg-1 in treatment with HCO3- and high concentrations of Ca and Mn (40 and 2 mg L-1, respectively). The percentage of arsenic associated with the manganese deposits in the plants exposed to 0.5 mg L-1 As(III) increased from 16.3% to 51.7% of the total arsenic accumulation at low and high Mn levels (<0.05 and 2 mg L-1, respectively), that accounted for the highest Mn-bound arsenic contribution. Surface oxidation of As(III) by MnOx and subsequent precipitation-adsorption of the formed As(V) onto the evolving structure of MnOx could be a plausible mechanism for arsenic removal. The presence, and in some cases dominance of arsenic bound to the biogenic Ca and Mn deposits on the studied aquatic plant may contribute to preservation of arsenic in sediments in a less bioavailable form upon its senescence and decomposition.