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Background: Intrahepatic cholangiocarcinoma (ICC) is a disease with poor prognosis and limited therapeutic options. We investigated the tumor immune microenvironment (TIME) to identify predictors of disease outcome and to explore targets for therapeutic modulation. Methods: Liver tissue samples were collected during 2008–2019 from patients (n = 139) diagnosed with ICC who underwent curative intent surgery without neoadjuvant chemotherapy. Samples from the discovery cohort (n = 86) were immunohistochemically analyzed on tissue microarrays (TMAs) for the expression of CD68, CD3, CD4, CD8, Foxp3, PD-L1, STAT1, and p-STAT1 in tumor core and stroma areas. Results were digitally analyzed using QuPath software and correlated with clinicopathological characteristics. For validation of TIME-related biomarkers, we performed multiplex imaging mass cytometry (IMC) in a validation cohort (n = 53). Results: CD68+ cells were the predominant immune cell type in the TIME of ICC. CD4+high T cell density correlated with better overall survival (OS). Prediction modeling together with validation cohort confirmed relevance of CD4+ cells, PD-L1 expression by immune cells in the stroma and N-stage on overall disease outcome. In turn, IMC analyses revealed that silent CD3+CD4+ clusters inversely impacted survival. Among annotated immune cell clusters, PD-L1 was most relevantly expressed by CD4+FoxP3+ cells. A subset of tumors with high density of immune cells ("hot" cluster) correlated with PD-L1 expression and could identify a group of candidates for immune checkpoint inhibition (ICI). Ultimately, higher levels of STAT1 expression were associated with higher lymphocyte infiltration and PD-L1 expression. Conclusions: These results highlight the importance of CD4+ T cells in immune response against ICC. Secondly, a subset of tumors with "hot" TIME represents potential candidates for ICI, while stimulation of STAT1 pathway could be a potential target to turn "cold" into "hot" TIME in ICC. TRANSLATIONAL RELEVANCE: The tumor immune microenvironment (TIME) plays a critical role in the immune response In many cancers, including intrahepatic cholangiocarcinoma (ICC). Molecular subtyping of the ICC microenvironment already revealed inter-tumoral heterogeneity with variant profiles of immune cell infiltrates. A recent study created an in-depth immune cell atlas of the TIME in biliary tract cancers and could demonstrate the relevance of specific immune cell subpopulations on patient outcome. We are able to provide a distinctive characterization of TIME, separating tumor epithelial- and stroma areas, in a large and representative ICC cohort using digitalized image analysis on tissue microarrays (TMA) as well as multiplex imaging mass cytometry (IMC). The study was designed for identification of immune cell prognosticators allocating institutional ICC patients into a discovery (2008–15) and a validation (2010–19) cohort. Immune cell subpopulations were correlated with clinicopathological characteristics and patient outcome. Our results highlight: i. The important role of CD4+ T cell infiltration in ICC patients; ii. ICC tumors with high density of immune cells associated with PD-L1 expression identifies a subset of patients with variant tumor biology; iii. Stimulation of STAT1 pathway may be a relevant target to turn "cold" into "hot" tumors. [ABSTRACT FROM AUTHOR]

Introduction The epithelium of the stomach corpus is organized into clonal units that are surrounded by myosin heavy chain 11-expressing ([MYH11.sup.+]) stromal cells. These units contain multiple differentiated cell types [...], The stomach corpus epithelium is organized into anatomical units that consist of glands and pits. Mechanisms that control the cellular organization of corpus glands and enable their recovery upon injury are not well understood. R-spondin 3 (RSPO3) is a WNT-signaling enhancer that regulates stem cell behavior in different organs. Here, we investigated the function of RSPO3 in the corpus during homeostasis, upon chief and/or parietal cell loss, and during chronic Helicobacter pylori infection. Using organoid culture and conditional mouse models, we demonstrate that RSPO3 is a critical driver of secretory cell differentiation in the corpus gland toward parietal and chief cells, while its absence promoted pit cell differentiation. Acute loss of chief and parietal cells induced by high dose tamoxifen--or merely the depletion of [LGR5.sup.+] chief cells caused an upregulation of RSPO3 expression, which was required for the initiation of a coordinated regenerative response via the activation of yes-associated protein (YAP) signaling. This response enabled a rapid recovery of the injured secretory gland cells. However, in the context of chronic H. pylori infection, the R-spondin-driven regeneration was maintained long term, promoting severe glandular hyperproliferation and the development of premalignant metaplasia.

Liver fibrosis progressing to cirrhosis is a major risk factor for liver cancer, impacting surgical treatment and survival. Our study focuses on the role of extracellular nicotinamide adenine dinucleotide (eNAD+) in liver fibrosis, analyzing liver disease patients undergoing surgery. Additionally, we explore NAD+'s therapeutic potential in a mouse model of extended liver resection and in vitro using 3D hepatocyte spheroids. eNAD+ correlated with aspartate transaminase (AST) and bilirubin after liver resection (AST: r = 0.2828, p = 0.0087; Bilirubin: r = 0.2584, p = 0.0176). Concordantly, post-hepatectomy liver failure (PHLF) was associated with higher eNAD+ peaks (n = 10; p = 0.0063). Post-operative eNAD+ levels decreased significantly (p < 0.05), but in advanced stages of liver fibrosis or cirrhosis, this decline not only diminished but actually showed a trend towards an increase. The expression of NAD+ biosynthesis rate-limiting enzymes, nicotinamide phosphoribosyltransferase (NAMPT) and nicotinamide mononucleotide adenylyltransferase 3 (NMNAT3), were upregulated significantly in the liver tissue of patients with higher liver fibrosis stages (p < 0.0001). Finally, the administration of NAD+ in a 3D hepatocyte spheroid model rescued hepatocytes from TNFalpha-induced cell death and improved viability (p < 0.0001). In a mouse model of extended liver resection, NAD+ treatment significantly improved survival (p = 0.0158) and liver regeneration (p = 0.0186). Our findings reveal that eNAD+ was upregulated in PHLF, and rate-limiting enzymes of NAD+ biosynthesis demonstrated higher expressions under liver fibrosis. Further, eNAD+ administration improved survival after extended liver resection in mice and enhanced hepatocyte viability in vitro. These insights may offer a potential target for future therapies. An analysis on liver disease patients suggests that extracellular Nicotinamide adenine dinucleotide (eNAD + ) correlates with liver fibrosis and post-hepatectomy liver failure, with NAD+ administration improving survival and liver regeneration in mice and hepatocyte viability in vitro. [ABSTRACT FROM AUTHOR]