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BackgroundThe cholecystokinin-2/gastrin receptor (Cck2r) is expressed in corpus isthmus progenitor, enterochromaffin-like and parietal cells, regulating acid secretion and cell turnover. However, the role of gastrin on Cck2r progenitors during mucosal regeneration remains unexplored.ObjectiveTo study the role of gastrin-Cck2r axis and corpus progenitors during gastric injury and regeneration.DesignWe generated Cck2r-CreERT2; Gastrin-DTR-p2A-TdTomato; Rosa26-ZsGreen mice to trace corpus Cck2r+ progenitors during homeostasis and injury, under conditions of hypogastrinaemia and hypergastrinaemia. Injury models included acute ulceration, chronic H. pylori gastritis and N-Nitroso-N-Methylurea (MNU) exposure.ResultsHypergastrinaemia significantly expanded Cck2r+ isthmus progenitors, whereas hypogastrinaemia reduced them. Gastric ulceration induced a twofold elevation in plasma gastrin by day 14, antral G-cell expansion and complete ulcer healing by day 28. Gastrin infusion or proton pump inhibitor (PPI) treatment further elevated gastrin and promoted complete ulcer healing by day 14, whereas G-cell ablation minimised gastrin, impaired healing and abrogated the benefits of PPI (p<0.05). The vagus nerve, through the muscarinic receptor 3, mediated both gastrin elevations and Cck2r+ progenitor expansion during ulcer healing. G-cell ablation in H. pylori-infected mice increased colonisation and exacerbated inflammation, atrophy, metaplasia and dysplasia (p<0.05), while hypergastrinaemia was protective. Similarly, in the MNU model, G-cell ablation worsened gastric pathology while hypergastrinaemia mitigated it.ConclusionsWe report a novel role for G-cell-derived gastrin in ulcer healing. Hypogastrinaemia is a risk factor for poor ulcer healing, corpus atrophy and potentially cancer, while physiological gastrin responses are protective. PPI-induced hypergastrinaemia plays a key role in ulcer healing, and gastrin signalling may prevent gastric preneoplasia.

Cancer cells have been shown to exploit neurons to modulate their survival and growth, including through the establishment of neural circuits within the central nervous system 1 , 2 – 3 . Here we report a distinct pattern of cancer–nerve interactions between the peripheral nervous system and gastric cancer. In multiple mouse models of gastric cancer, nociceptive nerves demonstrated the greatest degree of nerve expansion in an NGF-dependent manner. Neural tracing identified CGRP + peptidergic neurons as the primary gastric sensory neurons. Three-dimensional co-culture models showed that sensory neurons directly connect with gastric cancer spheroids. Chemogenetic activation of sensory neurons induced the release of calcium into the cytoplasm of cancer cells, promoting tumour growth and metastasis. Pharmacological ablation of sensory neurons or treatment with CGRP inhibitors suppressed tumour growth and extended survival. Depolarization of gastric tumour membranes through in vivo optogenetic activation led to enhanced calcium flux in jugular nucleus complex and CGRP release, defining a cancer cell–peptidergic neuronal circuit. Together, these findings establish the functional connectivity between cancer and sensory neurons, identifying this pathway as a potential therapeutic target. Functional connectivity between gastric cancer cells and sensory neurons offers a potential therapeutic target.

BackgroundWhile p53 mutations occur early in Barrett’s oesophagus (BE) progression to oesophageal adenocarcinoma (EAC), their role in gastric cardia stem cells remains unclear.ObjectiveThis study investigates the impact of p53 mutation on the fate and function of cardia progenitor cells in BE to EAC progression, particularly under the duress of chronic injury.DesignWe used a BE mouse model (L2-IL1β) harbouring a Trp53 mutation (R172H) to study the effects of p53 on Cck2r+ cardia progenitor cells. We employed lineage tracing, pathological analysis, organoid cultures, single-cell RNA sequencing (scRNA-seq) and computational analyses to investigate changes in progenitor cell behaviour, differentiation patterns and tumour progression. Additionally, we performed orthotopic transplantation of sorted metaplastic and mutant progenitor cells to assess their tumourigenic potential in vivo.ResultsThe p53 mutation acts as a switch to expand progenitor cells and inhibit their differentiation towards metaplasia, but only amidst chronic injury. In L2-IL1β mice, p53 mutation increased progenitors expansion and lineage-tracing with a shift from metaplasia to dysplasia. scRNA-seq revealed dysplastic cells arise directly from mutant progenitors rather than progressing through metaplasia. In vitro, p53 mutation enhanced BE progenitors’ organoid-forming efficiency, growth, DNA damage resistance and progression to aneuploidy. Sorted metaplastic cells grew poorly with no progression to dysplasia, while mutant progenitors gave rise to dysplasia in orthotopic transplantation. Computational analyses indicated that p53 mutation inhibited stem cell differentiation through Notch activation.Conclusionsp53 mutation contributes to BE progression by increasing expansion and fitness of undifferentiated cardia progenitors and preventing their differentiation towards metaplasia.

Background. Gastrointestinal stromal tumor (GIST) originates from a pacemaker cell, the Cajal cell. However, little is known about the cancer neuroscience in GIST. In this study, we aimed to elucidate the clinical and biological roles of adrenoceptor beta 2 (ADRB2) in GIST. Methods. Immunohistochemistry was used to evaluate the expression of ADRB2 in GIST tissues. The biological effects of ADRB2 on GIST cell proliferation, migration, invasion, and apoptosis were explored using Cell Counting Kit −8, plate colony formation assay, transwell invasion assay, and flow cytometry. We also explored the growth and metastasis of xenograft tumors in nude mice. Western blotting was used to quantify protein expression and phosphorylation. Results. ADRB2 is generally highly expressed in GIST. High ADRB2 expression was significantly associated with risk level, tumor size, mitotic count, and metastasis. Overexpression of ADRB2 promoted GIST cell proliferation, migration, invasion, and apoptosis, while silencing ADRB2 expression showed the opposite effects. Furthermore, we found that silencing endogenous ADRB2 inhibited GIST progression and metastasis in nude mice. ADRB2-induced ETV1 upregulation enhanced the activation of c-KIT. Conclusion. ADRB2 plays an important role in the proliferation and metastasis of GIST and is expected to be a potential target for the treatment of GIST.

Cancer cells have been shown to exploit neurons to modulate their survival and growth, including through establishment of neural circuits within the central nervous system (CNS) 1-3. Here, we report a distinct pattern of cancer-nerve interactions between the peripheral nervous system (PNS) and gastric cancer (GC). In multiple GC mouse models, nociceptive nerves demonstrated the greatest degree of nerve expansion in an NGF-dependent manner. Neural tracing identified CGRP+ peptidergic neurons as the primary gastric sensory neurons. Three-dimensional co-culture models showed that sensory neurons directly connect with gastric cancer spheroids through synapse-like structures. Chemogenetic activation of sensory neurons induced the release of calcium into the cytoplasm of cancer cells, promoting tumor growth and metastasis. Pharmacological ablation of sensory neurons or treatment with CGRP inhibitors suppressed tumor growth and extended survival. Depolarization of gastric tumor membranes through in vivo optogenetic activation led to enhanced calcium flux in nodose ganglia and CGRP release, defining a cancer cell-peptidergic neuronal circuit. Together, these findings establish the functional connectivity between cancer and sensory neurons, identifying this pathway as a potential therapeutic target.Competing Interest StatementThe authors have declared no competing interest.

expression defines a rare population of cells in the normal pancreas whose frequency is increased at early stages of pancreatic tumorigenesis. The identity and the precise roles of expressing cells in pancreas have been matter of debate, although evidence suggests their involvement in a number of key functions, including regeneration and neoplasia. We employed a recently developed Dclk1 reporter mouse model and single cell RNAseq analysis to define expressing cells in normal pancreas and pancreatic neoplasia. In normal pancreas, epithelial expression identifies subsets of ductal, islet and acinar cells. In pancreatic neoplasia, expression identifies five epithelial cell populations, among which acinar-to-ductal metaplasia (ADM)-like cells and tuft-like cells are predominant. These two cell populations play opposing roles in pancreatic neoplasia, with Dclk1 ADM-like cells sustaining tumor growth while Dclk1 tuft-like cells restraining tumor progression. The differentiation of Kras mutant acinar cells into Dclk1 tuft-like cells requires the activation of the transcription factor SPIB and is further supported by a cellular paracrine loop involving cancer group 2 innate lymphoid cells (ILC2) and cancer activated fibroblasts (CAFs) that provide IL13 and IL33, respectively. In turn, Dclk1 tuft-like cells release angiotensinogen that plays protective roles against pancreatic neoplasia. Overall, our study provides novel insights on the biology of Dclk1 cells in normal pancreas and unveils a protective axis against pancreatic neoplasia, involving CAFs, ILC2 and Dclk1 tuft-like cells, which ultimately results in angiotensinogen release.

Tu et al. show that Tff2 corpus isthmus cells are TA progenitors, and they, not chief cells, are the primary source of SPEM following injury. Upon Kras mutation, these progenitors directly progress to dysplasia, bypassing metaplasia, highlighting them as a potential origin of gastric cancer. Tff2 corpus cells are TA progenitors that give rise to secretory cells. Tff2 progenitors, not chief cells, are the primary source of SPEM after injury. Kras-mutant Tff2 progenitors progress directly to dysplasia, bypassing metaplasia. Multi-omics analysis reveals distinct trajectories for SPEM and gastric cancer. Pyloric metaplasia, also known as spasmolytic polypeptide-expressing metaplasia (SPEM), arises in the corpus in response to oxyntic atrophy, but its origin and role in gastric cancer remain poorly understood. Using knockin mice, we identified highly proliferative Tff2 progenitors in the corpus isthmus that give rise to multiple secretory lineages, including chief cells. While lacking long-term self-renewal ability, Tff2 corpus progenitors rapidly expand to form short-term SPEM following acute injury or loss of chief cells. Genetic ablation of Tff2 progenitors abrogated SPEM formation, while genetic ablation of GIF chief cells enhanced SPEM formation from Tff2 progenitors. In response to infection, Tff2 progenitors progressed first to metaplasia and then later to dysplasia. Interestingly, induction of Kras mutations in Tff2 progenitors facilitated direct progression to dysplasia in part through the acquisition of stem cell-like properties. In contrast, Kras-mutated SPEM and chief cells were not able to progress to dysplasia. Tff2 mRNA was downregulated in isthmus cells during progression to dysplasia. Single-cell RNA sequencing and spatial transcriptomics of human tissues revealed distinct differentiation trajectories for SPEM and gastric cancer. These findings challenge the conventional interpretation of the stepwise progression through metaplasia and instead identify Tff2 progenitor cells as potential cells of origin for SPEM and possibly for gastric cancer.

Nerves have been shown to regulate cancer progression. However, a clear demonstration of a role for axon guidance molecules in pancreatic tumorigenesis, innervation, and metastasis has been lacking. Using murine -mutant pancreatic organoids, we screened axon guidance molecules by qRT-PCR, identified upregulation, and then verified its upregulation during pancreatic tumorigenesis in humans and mice. NTN1 and its receptor NEO1 were upregulated in epithelial cells by the mutation and β-adrenergic signaling, in part, through the MAPK pathway. culture of celiac ganglia showed that NTN1 promoted the axonogenesis of sympathetic neurons through the nerve NEO1 receptor. In the model, knockout decreased sympathetic innervation and the development of pancreatic intraepithelial neoplasia. Treatment of pancreatic tumor organoids with recombinant NTN1 enhanced cell growth, epithelial-mesenchymal transition (EMT), and cancer stemness with the upregulation of ZEB1 and SOX9 through NEO1-mediated activation of focal adhesion kinase (FAK). In mice, knockout reduced innervation, FAK phosphorylation, and the features of EMT and stemness to extend mouse survival. In a liver metastasis model of PDAC (pancreatic ductal adenocarcinoma), treatment with a NTN1-neutralizing antibody or tumoral knockdown of reduced ZEB1 and SOX9 and decreased tumor progression. In contrast, overexpression promoted innervation and the progression of PDAC liver metastasis. These data suggest that the NTN1/NEO1 axis is a key regulator of PDAC progression, directly influencing cancer cell stemness and EMT, while indirectly promoting tumor growth through nerves. Inhibiting the NTN1/NEO1 axis could represent a potential therapeutic approach for PDAC.

Polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) are pathologically activated neutrophils that potently impair immunotherapy responses. The chemokine receptor CXCR4, a central regulator of hematopoiesis, represents an attractive PMN-MDSC target1. Here, we fused a secreted CXCR4 partial agonist TFF2 to mouse serum albumin (MSA) and demonstrated that TFF2-MSA peptide synergized with anti-PD-1 to induce tumor regression or eradication, inhibited distant metastases, and prolonged survival in multiple gastric cancer (GC) models. Using histidine decarboxylase (Hdc)-GFP transgenic mice to track PMN-MDSC , we found TFF2-MSA selectively reduced the immunosuppressive Hdc-GFP CXCR4 tumor PMN-MDSCs while preserving proinflammatory neutrophils, thereby boosting CD8 T cell-mediated anti-tumor response together with anti-PD-1. Furthermore, TFF2-MSA systemically reduced PMN-MDSCs and bone marrow granulopoiesis. In contrast, CXCR4 antagonism plus anti-PD-1 failed to provide a similar therapeutic benefit. In GC patients, expanded PMN-MDSCs containing a prominent CXCR4 LOX-1 subset are inversely correlated with the TFF2 level and CD8 T cells in circulation. Collectively, our studies introduce a strategy of using CXCR4 partial agonism to restore anti-PD-1 sensitivity in GC by targeting PMN-MDSCs and granulopoiesis.

Fibroblast activation protein (FAP) is regarded as a promising target for the diagnosis and treatment of tumors as it was overexpressed in cancer-associated fibroblasts. FAP inhibitors bearing a quinoline scaffold have been proven to show high affinity against FAP in vitro and in vivo , and the scaffold has been radio-labeled for the imaging and treatment of FAP-positive tumors. However, currently available FAP imaging agents both contain chelator groups to enable radio-metal labeling, making those tracers more hydrophilic and not suitable for the imaging of lesions in the brain. Herein, we report the synthesis, radio-labeling, and evaluation of a 18 F-labeled quinoline analogue ([ 18 F] 3 ) as a potential FAP-targeted PET tracer, which holds the potential to be blood–brain barrier-permeable. [ 18 F] 3 was obtained by one-step radio-synthesis via a copper-mediated S N A R reaction from a corresponding boronic ester precursor. [ 18 F] 3 showed moderate lipophilicity with a log D 7.4 value of 1.11. In cell experiments, [ 18 F] 3 showed selective accumulation in A549-FAP and U87 cell lines and can be effectively blocked by the pre-treatment of a cold reference standard. Biodistribution studies indicated that [ 18 F] 3 was mainly excreted by hepatic clearance and urinary excretion, and it may be due to its moderate lipophilicity. In vivo PET imaging studies indicated [ 18 F] 3 showed selective accumulation in FAP-positive tumors, and specific binding was confirmed by blocking studies. However, low brain uptake was observed in biodistribution and PET imaging studies. Although our preliminary data indicated that [ 18 F] 3 holds the potential to be developed as a blood–brain barrier penetrable FAP-targeted PET tracer, its low brain uptake limits its application in the detection of brain lesions. Herein, we report the synthesis and evaluation of [ 18 F] 3 as a novel small-molecule FAPI-targeted PET tracer, and our results suggest further structural optimizations would be needed to develop a BBB-permeable PET tracer with this scaffold.