Mutation spectrum in the Wnt/ß-catenin signaling pathway in gastric fundic gland-associated neoplasms/polyps.

Frequent activation of the Wnt/ß-catenin signaling pathway has recently been demonstrated in gastric adenocarcinoma/neoplasia of chief cell predominant type (GA-CCP/GN-CCP) with submucosal involvement. In this study, we examined the activation status of the Wnt/ß-catenin signaling pathway in GN-CCP without submucosal involvement, which is referred to as gastric dysplasia-CCP (GD-CCP). We also examined ß-catenin expression and the mutation spectrum of PPP2R1A and Wnt pathway genes in 11 cases of GD-CCP, 25 cases of gastric polyps of fundic gland type (GPs-FG), and 21 cases of GPs-FG with dysplasia (GP-FGD). ß-catenin nuclear staining was observed in 3 cases of GD-CCP, none of GPs-FG, and 6 cases of GPs-FGD. Mutations in Wnt pathway genes, including PPP2R1A, were observed in 4 cases of GDs-CCP, 10 cases of GPs-FG, and 7 cases of GPs-FGD. Two of these seven GPs-FGD cases showed ß-catenin nuclear staining. However, none of the 4 GD-CCP cases with mutations or the 10 GPs-FG cases with mutations showed ß-catenin nuclear staining. PPP2R1A mutations were observed in 1 GD-CCP case and 1 GPs-FGD case. Although the mutation spectra of the Wnt pathway genes in GD-CCP and GP-FG differed, based on the absence of ß-catenin nuclear staining despite the genetic alterations, GD-CCP is more similar to GP-FG than to GN-CCP, which shows ß-catenin nuclear staining and submucosal involvement. Activation of the Wnt/ß-catenin signaling by the ß-catenin nuclear transition may be required during progression from GD-CCP to GN-CCP. Furthermore, this is the first report describing PPP2R1A mutations in gastric fundic gland-associated neoplasms.

GNAS mutation as an alternative mechanism of activation of the Wnt/ß-catenin signaling pathway in gastric adenocarcinoma of the fundic gland type.

Gastric adenocarcinoma of the fundic gland type (GAFG) is a rare variant of gastric tumor. We have recently reported the frequent accumulation of ß-catenin in GAFGs and showed that approximately half of the cases studied harbored at least 1 mutation in CTNNB1/AXINs/APC, leading to the constitutive activation of the Wnt/ß-catenin pathway. However, the mechanisms of Wnt signaling activation in the remaining cases are unknown. Accumulating evidence showed that the activating mutation in GNAS promotes tumorigenesis via the activation of the Wnt/ß-catenin pathway or the ERK1/2 MAPK pathway. Therefore, we analyzed the mutations in GNAS (exons 8 and 9) and in KRAS (exon 2) in 26 GAFGs. Immunohistochemistry revealed nuclear ß-catenin expression in 22 of 26 GAFGs, and 10 (38.5%) of 26 cases harbored at least 1 mutation in CTNNB1/AXINs/APC. Activating mutations in GNAS were found in 5 (19.2%) of 26 GAFGs, all of which harbored R201C mutations. Activating mutations in KRAS were found in 2 (7.7%) of 26 GAFGs, and both of these also contained GNAS activating mutations. Four of 5 cases with GNAS mutation showed nuclear ß-catenin expression, and presence of GNAS mutation was associated with ß-catenin nuclear expression (P = .01). Furthermore, 3 of these 4 cases did not harbor mutations in CTNNB1, APC, or AXINs, suggesting that mutations in the Wnt component genes and those in GNAS occur almost exclusively. These results suggest that GNAS mutation might occur in a small subset of GAFG as an alternative mechanism of activating the Wnt/ß-catenin signaling pathway.

Reliability and validity of the Korean version of Morningness-Eveningness Questionnaire in adults aged 20-39 years.

Morningness-Eveningness (ME) can be defined by the difference in individual diurnal preference observed from general behavioral patterns including sleep habits. The Horne & Östberg Morningness-Eveningness Questionnaire (MEQ) has been used for classifying ME types. We examined the reliability of a Korean version of the MEQ (Korean MEQ) and verified its validity by comparing responses on the Korean MEQ to objectively-recorded sleep-wake rhythms. After translating and back translating the MEQ from English into Korean, we examined the internal consistency of 19 items of the Korean MEQ in 91 subjects, and the test-retest reliability in 21 subjects who took the Korean MEQ twice, 4 weeks apart. The Korean MEQ was then administered to 1022 young adult subjects. A subset of 46 morning, neither, and evening type subjects took part in a validation study in which their rest-activity timing was collected by actigraphy for 7 days. Cosinor analyses on these data were done to obtain the acrophase and amplitude of the sleep-wake rhythm. Cronbach's alpha of the total scores from the Korean MEQ was 0.77, and the test-retest reliability intra-class correlation coefficient was 0.90 (p < 0.0001). There was a significant negative correlation between Korean MEQ score and reported sleep-wake timing among the entire cohort (p < 0.0001). There was a significant difference in bedtime and wake time (on both work and free days), and in the mean sleep-wake rhythm acrophase, between ME types (p < 0.01). In this study, the validity of the Korean MEQ was verified by illustrating the difference in acrophases of the sleep-wake rhythm between the ME types in young adults.

Alteration in the Wnt/ß-catenin signaling pathway in gastric neoplasias of fundic gland (chief cell predominant) type.

Gastric neoplasia of chief cell-predominant type (GN-CCP) has been reported as a new, rare variant of gastric tumor. GN-CCPs were defined as tumors consisting of irregular anastomosing glands of columnar cells mimicking chief cells of fundic gland with nuclear atypia and prolapse-type submucosal involvement. We comparatively evaluated clinicopathologic features between 31 GN-CCPs and 130 cases of conventional gastric adenocarcinoma invading into submucosa (CGA-SM) in addition to nuclear ß-catenin immunolabeling and direct sequencing of members of the Wnt/ß-catenin pathway, CTNNB1, APC, and AXIN, in a subset of these tumors. GN-CCP presented as small protruded lesions located in the upper third of the stomach, with minimal involvement into the submucosa and rare lymphovascular invasion. None of the lesions have demonstrated a recurrence of disease or metastasis on follow-up. Nuclear ß-catenin immunolabeling was higher in GN-CCP (labeling index [LI]: median, 19.3%; high expresser [LI >30%], 7/27 cases [26%]) than CGA-SM (median LI, 14.7%; high expresser, 1/19 cases [6%]). Missense mutation of APC was observed in 1 GN-CCP but not CGA-SM. Missense or nonsense mutations of CTNNB1 and AXIN1 were higher in GN-CCPs (14.8%, both) than CGA-SMs (5.3%, both). Missense mutations of AXIN2 were higher in GN-CCPs (25.9%) than in CGA-SMs (10.5%). Overall, 14 (51.9%) of 27 GN-CCPs and 5 (26.3%) of 19 CGA-SM cases harbored at least 1 of these gene mutations. In conclusion, GN-CCPs as a unique variant of nonaggressive tumor are characterized by nuclear ß-catenin accumulation and mutation of CTNNB1 or AXIN gene, suggesting activation of the Wnt/ß-catenin pathway.

Multiple carcinoid tumors of the small intestine preoperatively diagnosed by double-balloon endoscopy.

BACKGROUND: Multiple carcinoid tumors of the small intestine are rare and are very difficult to detect preoperatively. CASE REPORT: A 75-year-old woman in whom the bleeding focus could not be found by upper and lower endoscopy and abdominal CT was admitted for evaluation of anemia. We examined the patient with total double-balloon endoscopy (DBE) and located multiple submucosal tumors. The multiple carcinoid tumors were resected successfully under laparoscopy. CONCLUSIONS: We report a case of a successful laparoscopic operation for multiple carcinoid tumors in the small intestine without intraoperative endoscopy. Total digestive tract observation using DBE is very useful for laparoscopic operation for multiple tumors in the small intestine.

7,12-Dimethylbenzanthracene induces apoptosis in RL95-2 human endometrial cancer cells: ligand-selective activation of cytochrome P450 1B1.

7,12-Dimethylbenzanthracene (DMBA), a polycyclic aromatic hydrocarbon, exhibits mutagenic, carcinogenic, immunosuppressive, and apoptogenic properties in various cell types. To achieve these functions effectively, DMBA is modified to its active form by cytochrome P450 1 (CYP1). Exposure to DMBA causes cytotoxicitymediated apoptosis in bone marrow B cells and ovarian cells. Although uterine endometrium constitutively expresses CYP1A1 and CYP1B1, their apoptotic role after exposure to DMBA remains to be elucidated. Therefore, we chose RL95-2 endometrial cancer cells as a model system for studying DMBA-induced cytotoxicity and cell death and hypothesized that exposure to DMBA causes apoptosis in this cell type following CYP1A1 and/or CYP1B1 activation. We showed that DMBA-induced apoptosis in RL95-2 cells is associated with activation of caspases. In addition, mitochondrial changes, including decrease in mitochondrial potential and release of mitochondrial cytochrome c into the cytosol, support the hypothesis that a mitochondrial pathway is involved in DMBA-induced apoptosis. Exposure to DMBA upregulated the expression of AhR, Arnt, CYP1A1, and CYP1B1 significantly; this may be necessary for the conversion of DMBA to DMBA-3,4-diol-1,2-epoxide (DMBA-DE). Although both CYP1A1 and CYP1B1 were significantly upregulated by DMBA, only CYP1B1 exhibited activity. Moreover, knockdown of CYP1B1 abolished DMBA-induced apoptosis in RL95-2 cells. Our data show that RL95-2 cells are susceptible to apoptosis by exposure to DMBA and that CYP1B1 plays a pivotal role in DMBA-induced apoptosis in this system.

The genome sequence of the ethanologenic bacterium Zymomonas mobilis ZM4.

We report the complete genome sequence of Zymomonas mobilis ZM4 (ATCC31821), an ethanologenic microorganism of interest for the production of fuel ethanol. The genome consists of 2,056,416 base pairs forming a circular chromosome with 1,998 open reading frames (ORFs) and three ribosomal RNA transcription units. The genome lacks recognizable genes for 6-phosphofructokinase, an essential enzyme in the Embden-Meyerhof-Parnas pathway, and for two enzymes in the tricarboxylic acid cycle, the 2-oxoglutarate dehydrogenase complex and malate dehydrogenase, so glucose can be metabolized only by the Entner-Doudoroff pathway. Whole genome microarrays were used for genomic comparisons with the Z. mobilis type strain ZM1 (ATCC10988) revealing that 54 ORFs predicted to encode for transport and secretory proteins, transcriptional regulators and oxidoreductase in the ZM4 strain were absent from ZM1. Most of these ORFs were also found to be actively transcribed in association with ethanol production by ZM4.