Gastric Phenotype Research Articles

A 34-year-old woman with mucolipidosis type IV predisposing to a neuroendocrine tumor in the gastric fundus

Abstract Introduction/Objective Mucolipidosis type IV (MLIV) is a lysosomal storage disorder with a gastric phenotype. Patients develop achlorhydia and compensatory hypergastrinemia, with pathology showing vacuolated parietal cells with lysosomal inclusions. MLIV is caused by mutation of TRPML1, a lysosomal membrane calcium channel required for trafficking proton pumps to the apical surface in parietal cells. We report the first case of MLIV predisposing to a neuroendocrine tumor (NET). This novel finding could impact management of patients with this disease, who may require frequent monitoring for NETs. We also show that immunohistochemistry for TRPML1 and H+/K+ ATPase can be used in conjunction to identify gastric MLIV. We hope that our updated immunohistochemical tools can aid in diagnosis of this disease. Methods/Case Report 34-year-old woman with MLIV requiring endoscopic resection for an incidentally discovered gastric polyp. Pathology showed Grade 2 NET invasion into submucosa (pT1). Background mucosa showed markedly vacuolated parietal cells, ranging from unilocular to multilocular with up to 20 vacuoles per cell. We stained the patient’s and a control stomach with antibodies against the TRPML1 and H+/K+ ATPase proteins. The H+/K+ ATPase antibody highlighted healthy parietal cells in the control stomach with strong cytoplasmic signal, but strikingly outlined lysosomal inclusions in MLIV parietal cells. TRPML-1 antibody showed cytoplasmic staining in parietal cells in the control. However, TRPML-1 staining showed markedly decreased signal in the patient and nuclear staining, possibly representing mislocalization. Results (if a Case Study enter NA) NA Conclusion We present the first case of MLIV predisposing to a NET in the stomach. NETs have potential for metastatic spread with subsequent mortality risk. Clinicians should maintain suspicion for NET development in this population, and protocols for frequent surveillance should be considered. This is also the first report using immunohistochemistry for TRPML1 and H+/K+ ATPase in combination to identify affected parietal cells in MLIV. Possibly, these tools can be used in the future by pathologists to diagnose MLIV.

Abstract C075: Ror2, a Novel Key Regulator Driving Cell Fate Decisions throughout Pancreatic Carcinogenesis

Abstract Introduction Reprogramming of pancreas cell fate drives development of pancreatic ductal adenocarcinoma (PDAC). Acinar cells, the most probable origin of pancreatic cancer, undergo a rapid cell identity switch towards a duct-like phenotype upon KrasG12D expression and when combined with pancreatitis or the loss of acinar differentiation factors. Metaplastic and neoplastic duct-like cells are heterogeneous with a proportion acquiring features reminiscent of gastric lineages. While some gastric signatures are maintained in the classical PDAC subtype, they are eroded in the more aggressive, basal-like PDAC. Since subtype identity has a major impact on prognosis and therapeutic targetability, druggable targets that regulate cellular reprogramming in pancreatic cancer can be exploited to increase sensitivity to therapy. Methods To elucidate mechanisms responsible for early reprogramming, pancreatic tissue of mice with conditional KrasG12D expression and loss of Pdx1 was analyzed by single-nucleus ATAC-seq. Expression of identified target genes was studied in precancerous lesions and PDAC by using multiplex RNAscope and IHC staining. Computational analyses of publicly available sequencing data were used to establish correlation to PDAC subtype identity. Genes were functionally studied in PDAC cell lines. Results By performing snATAC-seq and RNA-seq of early transformed pancreatic tissue, we discovered that acinar cells with the combined expression of KrasG12D and loss of Pdx1 activate expression of a gastric metaplastic gene signature accompanied by elevated levels of the receptor kinase Ror2. Ror2 is also highly expressed in distinct subpopulations of metaplastic and neoplastic cells, associated with a gastric neck cell phenotype and enhanced proliferative capacity. In contrast, Ror2Low lesions are characterized by a gastric pit cell-like and a senescent phenotype. Genetic ablation of Ror2 resulted in a shift in lesion identity, enriching those with a pit cell and senescent identity. In PDAC, we found that Ror2 anti-correlates with a similar gastric pit cell phenotype that is maintained in the classical subtype PDAC, but is strongly associated with the more aggressive basal-like subtype. Overexpression of ROR2 in human PDAC cell lines with a classical differentiation induced loss of the classical gene signature as well as epithelial-to-mesenchymal transition. Moreover, ROR2 enforces a strong dependency on AKT signaling, causing increased vulnerability of ROR2-expressing cells to AKT inhibition, but increased resistance to the KRAS inhibitor MRTX1133. Conclusions We discovered Ror2 as a critical determinant of precancerous lesion as well as PDAC subtype identity. Its role in driving an aggressive PDAC phenotype that is inherently resistant to Kras inhibition suggests that inhibiting this receptor tyrosine kinase will enhance sensitivity to the new generation of targeted therapies. Citation Format: Simone Benitz, Alec Steep, Malak Nasser, Jonathan Preall, Ujjwal Mukund Mahajan, Holly McQuithey, Ian Loveless, Erick T. Davis, Hui-Ju Wen, Daniel W. Long, Thomas Metzler, Samuel Zwernik, Michaela Louw, Donald Rempinski, Daniel Salas-Escabillas, Sydney Brender, Linghao Song, Ling Huang, Brian K. Theisen, Zhenyu Zhang, Nina G. Steele, Ivonne Regel, Filip Bednar, Howard C. Crawford. Ror2, a Novel Key Regulator Driving Cell Fate Decisions throughout Pancreatic Carcinogenesis [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C075.

Abstract B091: Spatial Transcriptomics Unveils Intraductal Papillary Mucinous Neoplasm Heterogeneity: From Novel Clusters to Immune Dynamics

Abstract Intraductal papillary mucinous neoplasms (IPMNs), a common precursor to pancreatic ductal adenocarcinoma, present as a spectrum of benign indolent behavior and progression to invasive carcinoma, which highlights the importance of identifying biomarkers of IPMN progression. This study utilized whole transcriptome spatial transcriptomics to define the molecular characteristics of Epithelial, Immune, and Fibroblast cell populations of the three distinct histological sub-types of IPMN to understand the dynamics between the cell types and identify biomarkers of neoplastic progression. Fifty-two surgically resected IPMN cores from 21 patients with resected IPMNs comprising 24 Gastric, 14 Intestinal, and 14 Pancreaticobiliary with a distribution of low-grade dysplasia (LGD), high-grade dysplasia (HGD), and Invasive carcinoma (IC) were analyzed. Epithelial, Immune, and Fibroblast components were analyzed using the GeoMx spatial profiler. Unsupervised hierarchical clustering of epithelial areas of interest (AOI) identified 3 distinct clusters demonstrating a spectrum of molecular phenotypes in IPMN that were correlated with the three histological subtypes. Comparing the gene expression profile based on the shared genes expressed on all three subtypes, the Intestinal type tends to have an overexpression of genes whereas the Pancreaticobiliary represents a repressed phenotype relative to the Gastric phenotype. Supervised clustering using Moffitt’s classifier to identify the Epithelial-Mesenchymal transition demonstrates the Pancreaticobiliary subtype to be more Basal-like versus the Gastric and Intestinal inclined towards the classical phenotype. Supervised clustering based on the degree of dysplasia within the epithelial compartments of each of these subtypes, demonstrated a spectrum of molecular heterogeneity and identified biomarkers specific to High-Grade dysplasia in the Gastric and Intestinal subtype. Immune AOI deconvolution analysis demonstrated that Tregs were associated with Pancreaticobiliary, Macrophage enrichment associated with the Intestinal phenotype, while there is enrichment of CD8 T-cell and CD4 T-cell gene signatures associated with the Gastric subtype. Fibroblast AOI analyses demonstrated heterogenous myCAF- iCAF signatures between the subtypes. In summary, Spatial whole transcriptome analysis of IPMN identifies molecular signatures in epithelial and immune compartments that differentiate between the three histological subtypes of IPMN and helps understand their progression from Low-grade dysplasia to High-grade dysplasia. Citation Format: Amaya Pankaj, Michael J Raabe, Yuhui Song, Bidish K Patel, Katherine Xu, Joshua R Kocher, Nicholas J Caldwell, Maria L Ganci, Linda T Nieman, Mari Mino-Kenudson, Vikram Deshpande, Nabeel Bardeesy, Carlos Fernandez-Del Castillo, Martin J Aryee, David T Ting, Yasmin G Hernandez-Barco. Spatial Transcriptomics Unveils Intraductal Papillary Mucinous Neoplasm Heterogeneity: From Novel Clusters to Immune Dynamics [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr B091.

Variability in morphology and immunohistochemistry of Crohn's disease-associated small bowel neoplasms: implications of Claudin 18 and Cadherin 17 expression for tumor-targeted immunotherapies.

Inflammatory bowel disease-associated colorectal carcinomas are known to have different morphology, immunoprofile, and genetic findings from sporadic colorectal carcinomas; however, little is known for Crohn's disease-associated small bowel neoplasms (CD-SBNs). Cadherin 17 is a useful biomarker of adenocarcinomas with intestinal phenotype and recently reported as an ideal target for chimeric antigen receptor T-cells (CAR-T) therapy for gastrointestinal carcinoma. Claudin 18 is a cell adhesion protein, and Claudin18 isoform 2 (CLDN18.2) is frequently expressed at high levels in gastric-type adenocarcinoma. Zolbetuximab, a targeted monoclonal antibody, has been developed for CLDN18.2-positive gastroesophageal adenocarcinoma. We examined a series of CD-SBNs for both Cadherin 17 and Claudin 18, and also hypothesized that expression of Claudin 18 was associated with gastric phenotype. We performed histological and immunohistochemical examinations on 25 CD-SBNs. Most of adenocarcinomas showed tubular morphology as seen in gastric carcinomas, whereas a subset of dysplasia was morphologically similar to that of the large bowel. Cadherin17 and Claudin 18 expression was identified in 93% and 57% CD-associated adenocarcinomas respectively. In Cadherin 17-positive CD-SBNs, frequent MUC5AC, MUC6, and Claudin18 expression was identified (61%, 57%, and 57%, respectively). Claudin 18-positive CD-SBNs showed significantly more MUC5AC and MUC6 expression than Claudin 18-negative CD-SBNs (P = 0.005, < 0.001 respectively). In CD-associated small bowel adenocarcinomas, Cadherin 17 expression was frequently retained and Claudin 18 was frequently co-expressed. Claudin 18 had a positive correlation with the expression of gastric mucins. These results suggest that CD-associated small bowel adenocarcinomas may be candidates for Cadherin 17- and Claudin 18-targeted immunotherapies.

Pseudogenization of NK3 homeobox 2 (Nkx3.2) in monotremes provides insight into unique gastric anatomy and physiology.

The enzymatic breakdown and regulation of food passage through the vertebrate antral stomach and pyloric sphincter (antropyloric region) is a trait conserved over 450 million years. Development of the structures involved is underpinned by a highly conserved signalling pathway involving the hedgehog, bone morphogenetic protein and Wingless/Int-1 (Wnt) protein families. Monotremes are one of the few vertebrate lineages where acid-based digestion has been lost, and this is consistent with the lack of genes for hydrochloric acid secretion and gastric enzymes in the genomes of the platypus (Ornithorhynchus anatinus) and short-beaked echidna (Tachyglossus aculeatus) . Furthermore, these species feature unique gastric phenotypes, both with truncated and aglandular antral stomachs and the platypus with no pylorus. Here, we explore the genetic underpinning of monotreme gastric phenotypes, investigating genes important in antropyloric development using the newest monotreme genomes (mOrnAna1.pri.v4 and mTacAcu1) together with RNA-seq data. We found that the pathway constituents are generally conserved, but surprisingly, NK3 homeobox 2 (Nkx3.2) was pseudogenized in both platypus and echidna. We speculate that the unique sequence evolution of Grem1 and Bmp4 sequences in the echidna lineage may correlate with their pyloric-like restriction and that the convergent loss of gastric acid and stomach size genotypes and phenotypes in teleost and monotreme lineages may be a result of eco-evolutionary dynamics. These findings reflect the effects of gene loss on phenotypic evolution and further elucidate the genetic control of monotreme stomach anatomy and physiology.

Gel immersion endoscopic mucosal resection of a duodenal adenoma with gastric phenotype.

Gel immersion endoscopic mucosal resection of a duodenal adenoma with gastric phenotype.

Perinatal High Fat Diet Exposure Reduces KCC2 Expression and Alters GABAergic Signaling in the Dorsal Motor Nucleus of the Vagus

Perinatal high fat diet (pHFD) exposure alters the development of vagal neurocircuits controlling gastrointestinal (GI) functions resulting in gastric motor dysfunction. GABAergic synaptic inhibition of vagal efferent motoneurons within the dorsal motor nucleus of the vagus (DMV) is critical in the brain’s ability to modulate gastric motility. This inhibition is maintained by KCC2, a Cl− transporter, who determines intracellular chloride concentration. The current study was designed to test the hypothesis that pHFD reduces KCC2 levels in DMV neurons, subsequently decreasing GABAergic inhibition and delaying gastric emptying rates. Pregnant Sprague-Dawley rats were fed either a control or high fat (14% vs 60% kcal from fat, respectively) diet from embryonic day 13, and offspring were used starting postnatal day 28. In vitro electrophysiological recordings were made from adult DMV neurons in brainstem slices. To assess the GABA-mediated inhibition, cell-attached recordings were made to preserve the internal Cl− concentration, and firing rate was quantified before and after application of bicuculline (BIC; 30μM), a GABAA antagonist. To determine the Cl− reversal potential, perforated patch clamp recordings were performed and the response to picospritz application of the GABAA agonist muscimol (100μM) was measured. KCC2 expression was quantified using pharmacology in the in vitro slice preparation, as well as immunofluorescence in brainstem cross-sections. Gastric emptying rates were quantified using the in vivo13C octanoic acid breath test technique. KCC2 transfection and induced expression in the DMV of pHFD rats was achieved using an adeno-associated viral vector. BIC increased firing rate in control DMV neurons (143.1% of baseline), but failed to increase DMV firing rate in DMV neurons from pHFD rats (96.27% of baseline; p=0.0103 using unpaired t-test). When control DMV neurons were treated with VU0240551 (VU; 10μM), a KCC2 blocker, BIC application led to a decrease in the firing rate (3.118 Hz to 1.606 Hz; p=0.0375 via paired t-test), demonstrating that antagonizing KCC2 attenuates GABAergic inhibition at this synapse. In control DMV neurons, the Cl− reversal potential was calculated to be -64.6mV. There was a depolarizing shift in Cl− reversal potential observed in pHFD neurons (-43.0mV; p=0.0007 using unpaired t-test). Application of VU shifted the chloride reversal from -64.6mV to -57.3mV in control neurons (p=0.0416 using a paired t-test). VU application had a reduced impact on pHFD neurons, shifting the reversal from -46.7mV to -45.0mV (p=0.1689 using a paired t-test), suggesting KCC2 downregulation. In fact, compared to control rats, there was a significant reduction in KCC2 expression in the pHFD DMV (2.237% area fluorescence in pHFD vs. 5.335%; p=0.0147 using unpaired t-test). When KCC2 expression was virally induced in young adult pHFD rats, GABA became inhibitory (163.7% of baseline firing rate after BIC application vs. 93.25% in pHFD + empty vector (EV); p=0.0019 using unpaired t-test), the Cl− reversal potential was normalized (-63.0mV vs. -49.7mV in pHFD + EV; p=0.0012 using an unpaired t-test), and gastric emptying rates were accelerated (58.7min vs 72.1min in pHFD + EV). Taken together, these results suggest that the loss of KCC2 function is a driver of the gastric pathophysiology seen in the pHFD rats, and that normalizing KCC2 levels can rescue the cellular and gastric phenotype. DK 111667. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The long intergenic non-coding RNA LINC01140 modulates gastric cancer phenotypes and cancer cell lines aggressiveness

BackgroundLong-intergenic non-protein coding gene 01140 (LINC01140) a long non-coding RNA is highly expressed in various cancers. However, its biological functions in gastric cancer progression is still unknown. MethodTo elucidate LINC01140 function, 70 GC tumor samples and 30 normal gastric tissues were collected. LINC01140 expression level were determined by qRT-PCR analysis and correlated with different clinico-pathological parameters. Then we tried to see the impact of LINC01140 on gastric cell line aggressiveness by knocking down the target gene and performing cell viability assay, migration assay and invasive capacity of the cell lines along with immunoblotting to check several protein levels. ResultLINC01140 RNA is found to be positively correlated with FGF9 and significantly up regulated in GC tissues. LINC01140 knockdown inhibited the viability, migratory capacity and invasive capacity of AGS cells. LINC01140 targets miR-140–5p, while miR-140–5p targeted FGF9 to form lncRNA–miRNA-mRNA axis. The affect of miR-140–5p inhibition on gastric cancer cell aggressiveness were opposite to those of LINC01140 or FGF9 knockdown. Additionally, inhibition partially reversed the effects of LINC01140 knockdown on FGF9 protein levels, gastric cancer cell phenotypes. ConclusionLINC01140, miR-140–5p and FGF9 form a lncRNA-miRNA-mRNA axis that modulates the gastric cancer phenotypes and in turn affects gastric cancer cell aggressiveness.

Abstract 3939: Ror2, a novel key regulator driving cell fate decisions throughout pancreatic tumor progression

Abstract Introduction: Reprogramming of pancreas cell fate drives development of pancreatic ductal adenocarcinoma (PDAC). Acinar cells, the most probable origin of pancreatic cancer, undergo a rapid cell identity switch towards a duct-like phenotype upon KrasG12D expression and when combined with pancreatitis or the loss of acinar differentiation factors. Metaplastic and dysplastic duct-like cells are heterogeneous with a proportion acquiring features reminiscent of gastric lineages. While some gastric signatures are maintained in the classical PDAC subtype, they are eroded in the more aggressive, basal-like PDAC. Since subtype identity has a major impact on prognosis and therapeutic targetability, druggable targets that regulate cellular reprogramming in pancreatic cancer can be exploited to increase sensitivity to therapy. Methods: To elucidate mechanisms responsible for early reprogramming, pancreatic tissue of mice with conditional KrasG12D expression and loss of Pdx1 was analyzed by single-nucleus ATAC-seq. Expression of identified target genes was studied in precancerous lesions and PDAC by using multiplex RNAscope and IHC staining. Computational analyses of publicly available sequencing data were used to establish correlation to PDAC subtype identity. Genes were functionally studied in PDAC cell lines. Results: By performing snATAC-seq and RNA-seq of early transformed pancreatic tissue, we discovered that acinar cells with the combined expression of KrasG12D and loss of Pdx1 activate expression of a gastric metaplastic gene signature accompanied by elevated levels of the receptor kinase Ror2. Ror2 is also highly expressed in distinct subpopulations of metaplastic and dysplastic cells, associated with a gastric neck cell phenotype and enhanced proliferative capacity. In contrast, Ror2Low lesions are characterized by a gastric pit cell-like and a senescent phenotype. Genetic ablation of Ror2 resulted in a shift in lesion identity, enriching those with a pit cell and senescent identity. In PDAC, we found that Ror2 anti-correlates with a similar gastric pit cell phenotype that is maintained in the classical subtype PDAC but is strongly associated with the more aggressive basal-like subtype. Overexpression of ROR2 in human PDAC cell lines with a classical differentiation induced loss of the classical gene signature as well as epithelial-to-mesenchymal transition. Moreover, ROR2 enforces a strong dependency on AKT signaling, causing increased vulnerability of ROR2-expressing cells to AKT inhibition, but increased resistance to the KRAS inhibitor MRTX1133. Conclusions: We discovered Ror2 as a critical determinant of precancerous lesion as well as PDAC subtype identity. Its role in driving an aggressive PDAC phenotype that is inherently resistant to Kras inhibition suggests that inhibiting this receptor tyrosine kinase will enhance sensitivity to the new generation of targeted therapies. Citation Format: Simone Benitz, Alexander Steep, Malak Nasser, Jonathan Preall, Ujjwal Mahajan, Ian Loveless, Holly McQuithey, Erick Davis, Hui-Ju Wen, Daniel Long, Thomas Metzler, Samuel Zwernik, Daniel Salas-Escabillas, Ling Huang, Nina Steele, Ivonne Regel, Filip Bednar, Howard Crawford. Ror2, a novel key regulator driving cell fate decisions throughout pancreatic tumor progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3939.

Abstract 3382: Unveiling gastric premalignancy: A comprehensive study of tumor initiation and evolution using organoid models

Abstract Tumor initiation and evolution is still a poorly characterized process. Organoid models recapitulate three-dimensional tissue structure, differentiation, and disease pathogenesis. These models can help to better characterize pre-neoplastic processes and tumor evolution, with implications for early cancer detection and personalized therapeutic strategies for patients with gastric cancer (GC). In our research, we performed whole exome sequencing (WES) on 24 GC patient tumors, uncovering distinct mutation frequencies in well-known tumor suppressor genes -APC, TP53, and ARID1A (18.75%, 37.5%, 43.75%, respectively) -compared to The Cancer Genome Atlas (TCGA) PanCancer Altas Cohort (n=440) (13.48%, 50.56%, 22.47% respectively). To gain a deeper understanding of how these mutated genes promote gastric premalignancy, we generated multiple isogenic gastric organoid lines with mutant APC (AT-dmut) or ARID1A (ArT-dmut) on a TP53 mutant background as well as TP53 mutant-only lines (T-mut) using our established CRISPR/Cas9 genome-editing platform and two HLA patient-derived normal gastric organoid lines (HL-PDOs). After confirmation of functional gene knockouts, we focused on elucidating carcinogenic changes via a two-pronged approach: (1) a comparative analysis of growth and morphology between these mutant organoid models and the parental normal gastric organoids and (2) an in-depth examination of mutational and transcriptional changes in our edited AT-mut, ArT-mut and T-mut organoid models. We cultured each edited organoid line for up to 350 days and collected histological and molecular data at multiple time points. Preliminary analysis shows an increased growth rate of all edited cell lines compared to parental normal lines. The ArT-mut and AT-mut cell lines exhibit distinct morphological and 3D structural alterations, while T-mut cell lines do not. We expect to find additional mutation gains in these cells’ lines compared to the parental normal gastric organoids that promote gastric phenotype with the greatest gain of alternations at the 350-day timepoint. These additional mutations and transcriptional changes will help us gain insights into the pathways altered in gastric cancer initiation and early progression that may be specific to HLAs. Our overall goal is to enhance our understanding of the molecular mechanisms underlying gastric premalignancy among HLAs, ultimately contributing to advancements in early detection and tailored therapeutic interventions for HLA patients with GC and advancing cancer health equity. Citation Format: Alexa Morales Arana, Nicole B. Halmai, Hongyong Zhang, Paul Lott, Ana Estrada, University of California Minority Patient-DerivedXenograft Development and Trial (UCaMP) Center, Luis Carvajal-Carmona. Unveiling gastric premalignancy: A comprehensive study of tumor initiation and evolution using organoid models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3382.

A case of duodenal adenocarcinoma with a gastric phenotype demonstrating a rapidly progressive course.

We herein report a rare case of duodenal adenocarcinoma with a rapidly progressive course. Esophagogastroduodenoscopy revealed Brunner's gland hyperplasia in the bulbs of the duodenum three years prior to this presentation. Two years earlier, gastric foveolar metaplasia had been observed in the bulbs. One year earlier, the lesion had increased slightly in size. At this time, the lesion had markedly increased in size, and the duodenum was circumferentially stenotic due to the mass. Pathologically, he was diagnosed with duodenal adenocarcinoma with a gastric-dominant immunophenotype and he died two months later. Although extremely rare, we should keep in mind that duodenal tumors with a gastric phenotype may sometimes progress rapidly within a short period of time.

CagA toxin and risk of Helicobacter pylori-infected gastric phenotype: A meta-analysis of observational studies.

Helicobacter pylori (H. pylori) is frequently associated with non-cardia type gastric cancer, and it is designated as a group I carcinogen. This study aimed to systematically review and meta-analyze the evidence on the prevalence of CagA status in people with gastric disorders in the Indo-Pacific region, and to examine the association of CagA positive in the risk of gastric disorders. This study focused on the Indo-Pacific region owing to the high disability adjusted life-years related to these disorders, the accessibility of efficient treatments for this common bacterial infection, and the varying standard of care for these disorders, particularly among the elderly population in the region. Relevant studies were identified in the health-related electronic databases including PubMed, Ovid, Medline, Ovid Embase, Index Medicus, and Google Scholar that were published in English between 1 January 2000, and 18 November 2023. For pooled prevalence, meta-analysis of proportional studies was done, after Freeman-Tukey double arcsine transformation of data. A random-effect model was used to compute the pooled odds ratio (OR) and 95% confidence interval (CI) to investigate the relationship between CagA positivity and gastric disorders. Twenty-four studies from eight Indo-Pacific countries (Bhutan, India, Indonesia, Malaysia, Myanmar, Singapore, Thailand, Vietnam) were included. Overall pooled prevalence of CagA positivity in H. pylori-infected gastric disorders was 83% (95%CI = 73-91%). Following stratification, the pooled prevalence of CagA positivity was 78% (95%CI = 67-90%) in H. pylori-infected gastritis, 86% (95%CI = 73-96%) in peptic ulcer disease, and 83% (95%CI = 51-100%) in gastric cancer. Geographic locations encountered variations in CagA prevalence. There was a greater risk of developing gastric cancer in those with CagA positivity compared with gastritis (OR = 2.53,95%CI = 1.15-5.55). Findings suggest that the distribution of CagA in H. pylori-infected gastric disorders varies among different type of gastric disorders in the study countries, and CagA may play a role in the development of gastric cancer. It is important to provide a high standard of care for the management of gastric diseases, particularly in a region where the prevalence of these disorders is high. Better strategies for effective treatment for high-risk groups are required for health programs to revisit this often-neglected infectious disease.

NNMT enriches for AQP5+ cancer stem cells to drive malignant progression in early gastric cardia adenocarcinoma

ObjectiveEarly gastric cardia adenocarcinoma (EGCA) is a highly heterogeneous cancer, and the understanding of its classification and malignant progression is limited. This study explored the cellular and molecular heterogeneity in...

Kinesin Family Member B18 Is Related to Gastric Mucin Phenotype and Contributes to Gastric Cancer Progression by Regulating Epithelial-Mesenchymal Transition

Introduction: Gastric cancer (GC) remains a common health concern worldwide and is the third leading cause of death in Japan. It can be broadly classified into gastric and intestinal mucin phenotypes using immunohistochemistry. We previously reported numerous associations of kinesin family member (KIF) genes and mucin phenotypes with GC. However, no previous studies have reported on the importance of KIF18B in GC using immunostaining. Thus, in this study, we investigated the expression and functions of KIF18B, which is highly expressed in gastric mucin phenotype GC. Methods: We performed RNA-seq of gastric and intestinal mucin type GCs, and clinicopathological studies of the KIF18B we found were performed using 96 GC cases. We also performed functional analysis using GC-derived cell lines. Result: RNA-seq showed the upregulation of matrisome-associated genes in gastric mucin phenotype GC and a high expression of KIF18B. KIF18B was detected in 52 of the 96 GC cases (54%) through immunohistochemistry. Low KIF18B expression was significantly associated with poor overall survival (p < 0.01). Other molecules that were significantly associated with KIF18B were MUC5AC and claudin 18; these were also significantly associated with the gastric mucin phenotype. KIF18B small interfering RNA (siRNA)-transfected GC cells showed greater growth and spheroid colony formation than the negative control siRNA-transfected cells. Furthermore, expression of snail family transcriptional repressor 1 and cadherin 2 was significantly increased and that of cadherin 1 was significantly decreased in KIF18B siRNA-transfected GC cells. Conclusion: These findings not only suggest that KIF18B may be a useful prognostic marker, but also provide insight into the pathogenesis of the GC phenotype.

Analysis of MUC6 polymorphisms on the clinicopathologic characteristics of Asian patients with oral squamous cell carcinoma.

Head and neck squamous cell carcinomas (HNSCCs) are generally associated with tobacco consumption, alcohol abuse or both. Mucins (MUCs) are high-molecular-weight glycoproteins produced by many epithelial tissues. Many studies have indicated that MUCs play an important role in cancer metastasis. MUC6 expression has been observed in gastric and oncocytic phenotypes and plays an important role during cancer progression. We found that levels of MUC6 are lower in Asian HNCC patients and affect the disease-free survival of HNCC patients. Next, we investigated the combined effect of MUC6 polymorphisms and exposure to environmental carcinogens on the susceptibility to and clinicopathological characteristics of HNCC. Three single-nucleotide polymorphisms (SNPs) of MUC6 (rs7481521, rs6597947 and rs61869016) were analysed using real-time PCR. After adjusting for other co-variants, we found that carrying a CC genotype at MUC6 rs6597947 led to a lower risk of developing oral squamous cell carcinoma (OSCC) than wild-type carriers among non-betel-quid chewers. Moreover, male oral cancer patients who carried the AA + CC genotype at MUC6 rs6597947 had a lower risk of lymph node metastasis than other genotypes, suggesting a significant functional compromise and decompensated disease. Therefore, our findings suggest that genetic variations in MUC6 may correlate to OSCC and indicate the progression in OSCC patients.

The cyclooxygenase-expressing mesenchyme resists intestinal epithelial injury by paracrine signaling

Paracrine signals play pivotal roles in organ homeostasis. Mesenchymal stromal cells (MSCs) play a key role in regulating epithelium homeostasis in the intestine while their paracrine effects are poorly characterized. Here, we identified prostaglandin E2 (PGE2) secreted by cyclooxygenase (COX)-expressing MSCs as a vital factor to maintain the intestinal mucosal barrier. We found that MSCs-induced organoid swelling through paracrine effect in vitro, a process due to enhanced water adsorption and is mediated by the COX-PGE2-EP4 axis. To further explore the regulatory effect of this axis on the intestinal epithelial barrier in vivo, we established the conditional knockout mouse model to specifically delete COX in MSCs and found that PGE2 reduction downregulated the gene Muc2 and induced a gastric metaplasia-like phenotype. Moreover, PGE2 defects increased the susceptibility of intestinal epithelium to colitis. Our study uncovers the paracrine signaling of COX-expressing MSCs in intestinal mucosal barrier maintenance, providing a basis for understanding the role of mesenchymal cells in the pathophysiological function of the intestine.

Expression Profiling along the Murine Intestine: Different Mucosal Protection Systems and Alterations in Tff1-Deficient Animals.

Tff1 is a typical gastric peptide secreted together with the mucin, Muc5ac. Tff1-deficient (Tff1KO) mice are well known for their prominent gastric phenotype and represent a recognized model for antral tumorigenesis. Notably, intestinal abnormalities have also been reported in the past in these animals. Here, we have compared the expression of selected genes in Tff1KO mice and their corresponding wild-type littermates (RT-PCR analyses), focusing on different mucosal protection systems along the murine intestine. As hallmarks, genes were identified with maximum expression in the proximal colon and/or the duodenum: Agr2, Muc6/A4gnt/Tff2, Tff1, Fut2, Gkn2, Gkn3, Duox2/Lpo, Nox1. This is indicative of different protection systems such as Tff2/Muc6, Tff1-Fcgbp, gastrokines, fucosylation, and reactive oxygen species (ROS) in the proximal colon and/or duodenum. Few significant transcriptional changes were observed in the intestine of Tff1KO mice when compared with wild-type littermates, Clca1 (Gob5), Gkn1, Gkn2, Nox1, Tff2. We also analyzed the expression of Tff1, Tff2, and Tff3 in the pancreas, liver, and lung of Tff1KO and wild-type animals, indicating a cross-regulation of Tff gene expression. Furthermore, on the protein level, heteromeric Tff1-Fcgbp and various monomeric Tff1 forms were identified in the duodenum and a high-molecular-mass Tff2/Muc6 complex was identified in the proximal colon (FPLC, proteomics).

A comparative study of gastric adenocarcinoma HER2 IHC phenotype and mass spectrometry-based quantification.

Gastric cancer is a highly heterogeneous malignant tumor of the digestive system. Anti-HER2 treatment can inhibit downstream signaling pathways and improve clinical treatment and outcomes in patients with HER2 protein overexpression. Currently, two standard methods for evaluating HER2 expression status are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). However, these low-throughput assays often produce discordant or equivocal results. In this study, we presented a new HER2 protein detection method based on mass spectrometry selected reaction monitoring (MS-SRM) and validated the method. We conducted a retrospective study on 118 formalin-fixed paraffin-embedded (FFPE) tissues from patients with advanced gastric adenocarcinoma in northern China, and we compared the MS-SRM results with those from IHC and correlated them with FISH. We established and validated the upper and lower detection limits (300-700 amol/μg) for abnormal HER2 protein expression in advanced gastric cancer. We also found that, among samples with mixed Lauren subtypes, those with a high level of HER2 expression had typical intestinal type features in pathology. This study demonstrated that the MS-SRM method can overcome the limitations and deficiencies of IHC, directly quantify the expression of HER2 protein in tumor cells and be used as a supplement to IHC. It has the potential to be used as a companion diagnosis for new drugs used to treat advanced gastric cancer. Large-scale clinical validation is required.

A pattern-recognition-based clustering method for non-invasive diagnosis and classification of various gastric conditions.

Conventional endoscopic biopsy tests are not suitable for early detection of the acute onset and progression of peptic ulcer as well as various gastric complications. This also limits its suitability for widespread population-based screening and consequently, many people with complex gastric phenotypes remain undiagnosed. Here, we demonstrate a new non-invasive methodology for accurate diagnosis and classification of various gastric disorders exploiting a pattern-recognition-based cluster analysis of a breathomics dataset generated from a simple residual gas analyzer-mass spectrometry. The clustering approach recognizes unique breathograms and "breathprints" signatures that clearly reflect the specific gastric condition of an individual person. The method can selectively distinguish the breath of peptic ulcer and other gastric dysfunctions like dyspepsia, gastritis, and gastroesophageal reflux disease patients from the exhaled breath of healthy individuals with high diagnostic sensitivity and specificity. Moreover, the clustering method exhibited a reasonable power to selectively classify the early-stage and high-risk gastric conditions with/without ulceration, thus opening a new non-invasive analytical avenue for early detection, follow-up, and fast population-based robust screening strategy of gastric complications in the real-world clinical domain.

Mucin-Phenotype and Expression of the Protein V-Set and Immunoglobulin Domain Containing 1 (VSIG1): New Insights into Gastric Carcinogenesis.

In gastric cancer (GC), intestinal metaplasia (IM) is a common precursor lesion, but its relationship to the MUC2/MUC5AC/CDX2 axis is not completely understood. Although V-set and immunoglobulin domain containing 1 (VSIG1) is supposed to be a specific marker for gastric mucosa and GC, respectively, no data about its relationship with IM or mucin phenotype have been published. The aim of our study was to explore the possible linkage between IM and these four molecules. The clinicopathological features of 60 randomly selected GCs were examined in association with VSIG1, MUC2, MUC5AC and CDX2. Two online database platforms were also used to establish the transcription factors (TFs) network involved in MUC2/MUC5AC/CDX2 cascade. IM was more frequently encountered in females (11/16 cases) and in patients below 60 years old (10/16 cases). Poorly differentiated (G3) carcinomas tended to show a loss of CDX2 (27/33 cases) but not of MUC2 and MUC5AC. MUC5AC and CDX2 were lost in parallel with the depth of invasion of the pT4 stage (28/35 and 29/35 cases), while an advanced Dukes-MAC-like stage was only correlated with CDX2 and VSIG1 loss (20/37 and 30/37 cases). VSIG1 was directly correlated with MUC5AC (p = 0.04) as an indicator of gastric phenotype. MUC2-negative cases showed a propensity towards lymphatic invasion (37/40 cases) and distant metastases, while CDX2-negative cases tended to associate with hematogenous dissemination (30/40 cases). Regarding the molecular network, only 3 of the 19 TFs involved in this carcinogenic cascade (SP1, RELA, NFKB1) interacted with all targeted genes. In GC, VSIG1 can be considered an indicator of gastric phenotype carcinomas, where carcinogenesis is mainly driven by MUC5AC. Although infrequently encountered in GC, CDX2 positivity might indicate a locally advanced stage and risk for vascular invasion, especially in tumors developed against the background of IM. The loss of VSIG1 indicates a risk for lymph node metastases.