Sustained Helicobacter pylori infection accelerates gastric dysplasia in a mouse model

More than 80% of gastric cancer is attributable to stomach infection with Helicobacter pylori (Hp). Gastric preneoplastic progression involves sequential tissue changes, including loss of parietal cells, metaplasia and dysplasia. In transgenic mice, active KRAS expression recapitulates these tissue changes in the absence of Hp infection. This model provides an experimental system to investigate additional roles of Hp in preneoplastic progression, beyond its known role in initiating inflammation. Tissue histology, gene expression, the immune cell repertoire, and metaplasia and dysplasia marker expression were assessed in KRAS+ mice +/-Hp infection. Hp+/KRAS+ mice had severe T-cell infiltration and altered macrophage polarization; a different trajectory of metaplasia; more dysplastic glands; and greater proliferation of metaplastic and dysplastic glands. Eradication of Hp with antibiotics, even after onset of metaplasia, prevented or reversed these tissue phenotypes. These results suggest that gastric preneoplastic progression differs between Hp+ and Hp- cases, and that sustained Hp infection can promote the later stages of gastric preneoplastic progression.

Consumer Decision-Making Creativity and Its Relation to Exploitation-Exploration Activities: Eye-Tracking Approach

Modern consumers face a dramatic rise in web-based technological advancements and have trouble making rational and proper decisions when they shop online. When they try to make decisions about products and services, they also feel pressured against time when sorting among all of the unnecessary items in the flood of information available on the web. In this sense, they need to use consumer decision-making creativity (CDMC) to make rational decisions. However, unexplored research questions on this subject remain. First, in what ways do task difficulty and time constraints affect visual attention on exploitative and exploratory activities differently? Second, how does the location of the reference (i.e., hints) influence the level of visual attention to exploitative and exploratory activities depending on affordance theory? Third, how do exploratory and exploitative activities affect CDMC? Eye-tracking experiments were conducted with 70 participants to obtain relevant metrics such as total fixation duration (TFD), fixation count (FC), and visit count (VC) to answer these research questions. Our findings suggest that task difficulty influences exploitative activity, whereas time constraint is related to the exploratory activity. The result of the location of hints aligns with the affordance theory for the exploitative activity. Besides, exploratory activity positively affected CDMC, but exploitative activity did not show any effect.

Achieving Low VOC-deficit Characteristics in Cu2ZnSn(S,Se)4 Solar Cells through Improved Carrier Separation

Kesterite-based thin-film solar cells (TFSCs) have recently gained significant attention in the photovoltaic (PV) sector for their elemental earth abundance and low toxicity. An inclusive study from the past reveals basic knowledge about the grain boundary (GB) and grain interior (GI) interface. However, the compositional dependency of the surface potential within GBs and GIs remains unclear. The present work provides insights into the surface potential of the bulk and GB interfaces. The tin (Sn) composition is sensitive to the absorber morphology, and therefore, it significantly impacts absorber and device properties. The absorber morphology improves with the formation of larger grains as the Sn content increases. Additionally, the presence of Sn(S,Se)₂ and increased [Zn_Cu + V_Cu] A-type defect cluster density are observed, validated through Raman analysis. The secondary ion mass spectroscopy analysis reveals the altered distribution of sulfur (S) and sodium (Na) with higher near-surface accumulation. The synergistic outcome of the increased density of defects and the accumulation of S near the interface provides a larger GB and GI difference and expedites carrier separation improvement. Consequently, at an optimum compositional ratio of Cu/(Zn+Sn) = ∼0.6, the power conversion efficiency (PCE) is significantly improved from 6.42 to 11.04% with a record open-circuit voltage (V_OC) deficit of 537 mV.

Abstract PO-051: Tumor stem cells arising from a non-stem origin maintain a differentiated phenotype and modulate T cell activity

Tumor stem cells (TSCs) contribute to cancer mortality via therapeutic resistance, tumor recurrence, and metastatic mechanisms. However, the origins of the stem capacity to TSCs remains in question, but all TSCs descend from the original tumor cell-of-origin where the first oncogenic event occurred. Tumors arising from different cells-of-origin are histologically identical, but it is unknown whether TSCs that arose from different origins are molecularly and functionally distinct. Using mouse models driving identical Apc mutations from Lrig1-expressing and Mist1-expressing cells, we characterized TSCs of tumors driven from stem and non-stem cells-of-origin using single cell RNA sequencing (scRNA-seq), organoids, and multiplexed imaging. We revealed reduced stem capacity but increased class II antigen presentation ability for non-stem cell (Mist1) driven TSCs compared with stem cell (Lrig1) driven TSCs, which resulted in a favorable immune microenvironment skewed towards active cytotoxic response in Mist1-driven tumors. These results suggest that the cell-of-origin of tumorigenesis provides a specific context by which TSCs are generated, dictating their interactions with the tumor microenvironment.

Citation Format: Cherie’ R. Scurrah, Bob Chen, Nick Markham, Alan Simmons, Austin Southard-Smith, Mary Macedonia, Eunyoung Choi, Qi Liu, Kay Washington, Bob Coffey, Jeremy Goettel, Ken Lau. Tumor stem cells arising from a non-stem origin maintain a differentiated phenotype and modulate T cell activity [abstract]. In: Proceedings of the AACR Virtual Special Conference on Tumor Heterogeneity: From Single Cells to Clinical Impact; 2020 Sep 17-18. Philadelphia (PA): AACR; Cancer Res 2020;80(21 Suppl):Abstract nr PO-051.

CRISPR-Cas12a with an oAd Induces Precise and Cancer-Specific Genomic Reprogramming of EGFR and Efficient Tumor Regression

CRISPR-Cas12a represents a class 2/type V CRISPR RNA-guided endonuclease, holding promise as a precise genome-editing tool in vitro and in vivo. For efficient delivery of the CRISPR-Cas system into cancer, oncolytic adenovirus (oAd) has been recognized as a promising alternative vehicle to conventional cancer therapy, owing to its cancer specificity; however, to our knowledge, it has not been used for genome editing. In this study, we show that CRISPR-Cas12a mediated by oAd disrupts the oncogenic signaling pathway with excellent cancer specificity. The intratumoral delivery of a single oAd co-expressing a Cas12a and a CRISPR RNA (crRNA) targeting the epidermal growth factor receptor (EGFR) gene (oAd/Cas12a/crEGFR) induces efficient and precise editing of the targeted EGFR gene in a cancer-specific manner, without detectable off-target nuclease activity. Importantly, oAd/Cas12a/crEGFR elicits a potent antitumor effect via robust induction of apoptosis and inhibition of tumor cell proliferation, ultimately leading to complete tumor regression in a subset of treated mice. Collectively, in this study we show precise genomic reprogramming via a single oAd vector-mediated CRISPR-Cas system and the feasibility of such system as an alternative cancer therapy.

microRNA-30a arbitrates intestinal-type early gastric carcinogenesis by directly targeting ITGA2

BACKGROUND

Spasmolytic polypeptide-expressing metaplasia (SPEM) is considered a precursor lesion of intestinal metaplasia and intestinal-type gastric cancer (GC), but little is known about microRNA alterations during metaplasia and GC developments. Here, we investigate miR-30a expression in gastric lesions and identify its novel target gene which is associated with the intestinal-type GC.

METHODS

We conducted in situ hybridization and qRT-PCR to determine miR-30a expression in gastric tissues. miR-30a functions were determined through induction or inhibition of miR-30a in GC cell lines. A gene microarray was utilized to confirm miR-30a target genes in GC, and siRNA-mediated target gene suppression and immunostaining were performed. The Cancer Genome Atlas data were utilized to validate gene expressions.

RESULTS

We found down-regulation of miR-30a during chief cell transdifferentiation into SPEM. MiR-30a level was also reduced in the early stage of GC, and its level was maintained in advanced GC. We identified a novel target gene of miR-30a and ITGA2, and our results showed that either ectopic expression of miR-30a or ITGA2 knockdown suppressed GC cell proliferation, migration, and tumorigenesis. Levels of ITGA2 inversely correlated with levels of miR-30a in human intestinal-type GC.

CONCLUSION

We found down-regulation of miR-30a in preneoplastic lesions and its tumor-suppressive functions by targeting ITGA2 in GC. The level of ITGA2, which functions as an oncogene, was up-regulated in human GC. The results of this study suggest that coordination of the miR-30a-ITGA2 axis may serve as an important mechanism in the development of gastric precancerous lesions and intestinal-type GC.

Trop2 is upregulated in the transition to dysplasia in the metaplastic gastric mucosa

Intestinal-type gastric adenocarcinoma arises in a field of pre-existing metaplasia. While biomarkers of cancer and metaplasia have been identified, the definition of dysplastic transition as a critical point in the evolution of cancer has remained obscure. We have evaluated Trop2 as a putative marker of the transition from metaplasia to dysplasia in the stomach in multiple mouse models of metaplasia induction and progression. In addition, TROP2 expression was evaluated in human samples by immunostaining tissue microarrays for metaplasia, dysplasia, and gastric cancer. Dysplastic mouse organoids were evaluated in vitro following shRNA knockdown of Trop2 expression. In mouse models, no Trop2 was observed in the normal corpus and Trop2 was not induced in acute models of metaplasia induction with either L635 or DMP-777. In Mist1-Kras mice, Trop2 expression was not observed in metaplasia at 1 month after Kras induction, but was observed in dysplastic glands at 3-4 months after Kras induction. In human tissues, no Trop2 was observed in normal corpus mucosa or SPEM, but Trop2 expression was observed in incomplete intestinal metaplasia, with significantly less expression in complete intestinal metaplasia. Trop2 expression was observed in all dysplastic and 84% of gastric cancer lesions, although expression levels were variable. Dysplastic mouse organoids from Mist1-Kras mice expressed Trop2 strongly. Knockdown of Trop2 with shRNA markedly reduced organoid growth and budding behavior, and induced the upregulation of apical villin expression. We conclude that Trop2 is upregulated in the transition to dysplasia in the stomach and promotes dysplastic cell behaviors. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The use of motivational interviewing during an interdisciplinary Service-Learning activity for older adults at risk for dementia

This study aimed to develop a service-learning program based on motivational interviewing for older adults living alone and at risk for dementia. This paper focused on description and implementation of the developed program and students' preliminary outcomes as a mixed-methods pilot study. Participants were nine students in occupational therapy, physical therapy, and social work and three older adults matched to each of the three interdisciplinary student groups. Students' attitudes about community service improved. Also, participation in the program was regarded as a new useful experience that helped in realizing the importance of interprofessional collaboration, expanding knowledge about other disciplines, contributing to the community and professional development, and understanding older adults living alone. Future study should include a larger sample size and measure the program's effectiveness for both the students and older adults.

Magnetic Reconnection Inside a Flux Rope Induced by Kelvin-Helmholtz Vortices

On 5 May 2017, MMS observed a crater-type flux rope on the dawnside tailward magnetopause with fluctuations. The boundary-normal analysis shows that the fluctuations can be attributed to nonlinear Kelvin-Helmholtz (KH) waves. Reconnection signatures such as flow reversals and Joule dissipation were identified at the leading and trailing edges of the flux rope. In particular, strong northward electron jets observed at the trailing edge indicated midlatitude reconnection associated with the 3-D structure of the KH vortex. The scale size of the flux rope, together with reconnection signatures, strongly supports the interpretation that the flux rope was generated locally by KH vortex-induced reconnection. The center of the flux rope also displayed signatures of guide-field reconnection (out-of-plane electron jets, parallel electron heating, and Joule dissipation). These signatures indicate that an interface between two interlinked flux tubes was undergoing interaction, causing a local magnetic depression, resulting in an M-shaped crater flux rope, as supported by reconstruction.

Superconductivity in a uranium containing high entropy alloy

High entropy alloys (HEA) are an unusual class of materials where mixtures of elements are stochastically arrayed on a simple crystalline lattice. These systems exhibit remarkable functionality, often along several distinct axes: e.g., the examples [TaNb]1-x(TiZrHf)x are high strength and damage resistant refractory metals that also exhibit superconductivity with large upper critical fields. Here we report the discovery of an f-electron containing HEA, [TaNb]0.31(TiUHf)0.69, which is the first to include an actinide ion. Similar to the Zr-analogue, this material crystallizes in a body-centered cubic lattice with the lattice constant a = 3.41(1) Å and exhibits phonon mediated superconductivity with a transition temperatures Tc ≈ 3.2 K and upper critical fields Hc2 ≈ 6.4 T. These results expand this class of materials to include actinide elements, shows that superconductivity is robust in this sub-group, and opens the path towards leveraging HEAs as functional waste forms for a variety of radioisotopes.

Heterogeneity and dynamics of active Kras-induced dysplastic lineages from mouse corpus stomach

Dysplasia is considered a key transition state between pre-cancer and cancer in gastric carcinogenesis. However, the cellular or phenotypic heterogeneity and mechanisms of dysplasia progression have not been elucidated. We have established metaplastic and dysplastic organoid lines, derived from Mist1-Kras(G12D) mouse stomach corpus and studied distinct cellular behaviors and characteristics of metaplastic and dysplastic organoids. We also examined functional roles for Kras activation in dysplasia progression using Selumetinib, a MEK inhibitor, which is a downstream mediator of Kras signaling. Here, we report that dysplastic organoids die or show altered cellular behaviors and diminished aggressive behavior in response to MEK inhibition. However, the organoids surviving after MEK inhibition maintain cellular heterogeneity. Two dysplastic stem cell (DSC) populations are also identified in dysplastic cells, which exhibited different clonogenic potentials. Therefore, Kras activation controls cellular dynamics and progression to dysplasia, and DSCs might contribute to cellular heterogeneity in dysplastic cell lineages.

P3762The impact of type and burden of atrial fibrillation on stroke occurrence in patients with atrial fibrillation: from a prospective cohort of atrial fibrillation patients (CODE-AF Registry)

Background and purpose

Although several studies reported that stroke risk in patients with paroxysmal atrial fibrillation (AF) is similar to those with persistent or permanent AF, there is still controversy on the relationship of AF type and stroke occurrence. We investigated the effect of AF type on AF burden and stroke risk in patients with non-valvular AF.

Methods

Within the CODE-AF prospective, outpatient registry (COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation), we identified 8,883 patients ≥18 years of age with non-valvular AF and eligible follow-up visits. We compared AF burden and stroke risk among patients with 3 types of AF: paroxysmal (n=5,808) or persistent (n=2,806) or permanent (n=269).

Results

The median age of the overall population was 68.0 (interquartile range, 60.0–75.0); 36.0% were female. Patients with persistent and permanent AF were older and had higher CHA2DS2-VASc scores and anticoagulation rate than those with paroxysmal AF. Compared with permanent AF (5.2±16.4%), the arrhythmic burden of AF on 24hrs Holter monitoring was significantly lower in paroxysmal AF (2.1±7.2%, p<0.001) and persistent AF (2.0±7.5%, p<0.001). During median follow-up period of 1.38 years (interquartile range: 0.96–1.67), total 82 (0.92%) patients experienced ischemic stroke with incidence rates of 0.51, 1.04 and 1.69 events per 100 person-years for paroxysmal, persistent and permanent AF, respectively. Compared with paroxysmal AF, the risk of ischemic stroke was increased in persistent AF with clinical variable adjusted hazard ratio (aHR) of 1.94 (95% confidence intervals [CI], 1.23–3.07; P=0.005) and permanent AF with aHR of 2.64 (95% CI, 1.09–6.41; P=0.03).

AF type and HR of stroke occurrence Paroxysmal (n=5,808) Persistent (n=2,806) Permanent (n=269) Stoke events 39 37 6 Person years (PYs) 7673 3544 356 /100 PYs 0.51 1.04 1.69 HR (95% CI), p-value HR (95% CI), p-value HR (95% CI), p-value Unadjusted HR 1 (Reference) 2.05 (1.27–3.31), 0.003 3.32 (1.15–7.90), 0.02 Clinical variables adjusted HR 1 (Reference) 1.94 (1.23–3.07), 0.005 2.64 (1.09–6.41), 0.03 PYs: Person years; HR: Hazard ratio.

Conclusion

Persistent and permanent AF was associated with the increased risk of stroke than paroxysmal AF, after adjustment of clinical variables including age, sex, comorbidities and anticoagulation rate. These results suggest that AF type and burden might be related with the risk of ischemic stroke and should be considered in the stroke prevention of AF.

Targeted mobilization of Lrig1+ gastric epithelial stem cell populations by a carcinogenic Helicobacter pylori type IV secretion system

Helicobacter pylori-induced gastritis is the strongest risk factor for gastric adenocarcinoma, a malignancy preceded by a series of well-defined histological stages, including metaplasia. One microbial constituent that augments cancer risk is the cag type 4 secretion system (T4SS), which translocates the oncoprotein CagA into host cells. Aberrant stem cell activation is linked to carcinogenesis, and Lrig1 (leucine-rich repeats and Ig-like domains 1) marks a distinct population of progenitor cells. We investigated whether microbial effectors with carcinogenic potential influence Lrig1 progenitor cells ex vivo and via lineage expansion within H. pylori-infected gastric mucosa. Lineage tracing was induced in Lrig1-CreERT2/+;R26R-YFP/+ (Lrig1/YFP) mice that were uninfected or subsequently infected with cag+H. pylori or an isogenic cagE- mutant (nonfunctional T4SS). In contrast to infection with wild-type (WT) H. pylori for 2 wk, infection for 8 wk resulted in significantly increased inflammation and proliferation in the corpus and antrum compared with uninfected or mice infected with the cagE- mutant. WT H. pylori-infected mice harbored significantly higher numbers of Lrig1/YFP epithelial cells that coexpressed UEA1 (surface cell marker). The number of cells coexpressing intrinsic factor (chief cell marker), YFP (lineage marker), and GSII lectin (spasmolytic polypeptide-expressing metaplasia marker) were increased only by WT H. pylori In human samples, Lrig1 expression was significantly increased in lesions with premalignant potential compared with normal mucosa or nonatrophic gastritis. In conclusion, chronic H. pylori infection stimulates Lrig1-expressing progenitor cells in a cag-dependent manner, and these reprogrammed cells give rise to a full spectrum of differentiated cells.

Decrease in MiR-148a Expression During Initiation of Chief Cell Transdifferentiation

Gastric chief cells differentiate from mucous neck cells and develop their mature state at the base of oxyntic glands with expression of secretory zymogen granules. After parietal cell loss, chief cells transdifferentiate into mucous cell metaplasia, designated spasmolytic polypeptide-expressing metaplasia (SPEM), which is considered a candidate precursor of gastric cancer. We examined the range of microRNA (miRNA) expression in chief cells and identified miRNAs involved in chief cell transdifferentiation into SPEM. Among them, miR-148a was strongly and specifically expressed in chief cells and significantly decreased during the process of chief cell transdifferentiation. Interestingly, suppression of miR-148a in a conditionally immortalized chief cell line induced up-regulation of CD44 variant 9 (CD44v9), one of the transcripts expressed at an early stage of SPEM development, and DNA methyltransferase 1 (Dnmt1), an established target of miR-148a. Immunostaining analyses showed that Dnmt1 was up-regulated in SPEM cells as well as in chief cells before the emergence of SPEM in mouse models of acute oxyntic atrophy using either DMP-777 or L635. In the cascade of events that leads to transdifferentiation, miR-148a was down-regulated after acute oxyntic atrophy either in xCT knockout mice or after sulfasalazine inhibition of xCT. These findings suggest that the alteration of miR-148a expression is an early event in the process of chief cell transdifferentiation into SPEM.

A-23 Mental Illness and Emotional Functioning as Moderated by Executive Functioning: Incarcerated Population

Objective

The purpose of this study is to investigate whether executive functioning will moderate the relationship of a history of mental illness on aggression in a male forensic population.

Method

Using an archival database from a larger study, 232 male inmates (ages 21 and 49 years old) from three medium/maximum Maryland Correctional facilities were recruited using a pseudo-random selection process during intake. Participants were administered three EF tasks (Cambridge Decision Making Task, Logan Stop-Signal Task, and Stroop Interference Task), history of mental illness was obtained using the Symptom Checklist-90, and aggression was assessed with the Novaco Reaction to Provocation Questionnaire.

Results

Hierarchical multiple regressions were conducted. For overall aggression reactivity, inhibition moderated depression (IR2 = .025, F(3, 224) = 9.977, p < .001, β = -.246, p = .015) and psychoticism (IR2 = .019, F(3, 224) = 8.216, p < .001, β = -.136, p = .031). For reactive aggression subtype, inhibition moderated depression (IR2 = .025, F(3, 224) = 2.679, p = .048, β = .071, p = .017). For proactive aggression subtype, cognitive flexibility moderated anxiety (IR2 = .018, F(3, 224) = 4.731, p = .003, β = -.014, p = .039); and depression (IR2 = .022, F(3, 224) = 3.888, p = .010, β = -.017, p = .025).

Conclusions

Overall, there was mixed findings for inhibition. On Cambridge Decision Making task, inhibition moderated the predictive relationship of depression on reactive aggression and psychoticism and overall aggression but not for other measures of inhibition. For another inhibition task (Stroop), inhibition did not significantly moderate any mental illness on severity of aggression. Cognitive flexibility moderated the predictive relationships of anxiety and depression on proactive aggression. Findings suggest targeting cognitive flexibility for inmates diagnosed with anxiety depression, and psychosis when treating aggression in a male forensic population.