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Loss of Lrig1 leads to expansion of Brunner glands followed by duodenal adenomas with gastric metaplasia.

ABSTRACT: Leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) is a pan-ErbB negative regulator and intestinal stem cell marker down-regulated in many malignancies. We previously reported that 14 of 16 Lrig1-CreERT2/CreERT2 (Lrig1(-/-)) mice developed duodenal adenomas, providing the first in vivo evidence that Lrig1 acts as a tumor suppressor. We extended this study to a larger cohort and found that 49 of 54 Lrig1(-/-) mice develop duodenal adenomas beginning at 3 months. Most adenomas were histologically low grade and overlaid expanded Brunner glands. There was morphologic and biochemical blurring of the boundary between the epithelium and Brunner glands with glandular coexpression of ErbB2, which is normally restricted to the epithelium, and the Brunner gland marker Mucin6. Some adenomas were high grade with reduced Brunner glands. At age 4 to 5 weeks, before adenoma formation, we observed enhanced proliferation in Brunner glands and, at 2 months, an increase in the size of the Brunner gland compartment. Elevated expression of the epidermal growth factor receptor (Egfr) ligands amphiregulin and ?-cellulin, as well as Egfr and phosphorylated Egfr, was detected in adenomas compared with adjacent normal tissue. These adenomas expressed the gastric-specific genes gastrokine1 and mucin5ac, indicating gastric metaplasia. Moreover, we found that a subset of human duodenal tumors exhibited features of LRIG1(-/-) adenomas, including loss of LRIG1, gastric metaplasia (MUCIN5AC and MUCIN6), and increased amphiregulin and Egfr activity.

SUBMITTER: Wang Y

PROVIDER: S-EPMC4380843 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature

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Loss of Lrig1 leads to expansion of Brunner glands followed by duodenal adenomas with gastric metaplasia.

Wang Yang Y Shi Chanjuan C Lu Yuanyuan Y Poulin Emily J EJ Franklin Jeffery L JL Coffey Robert J RJ

The American journal of pathology 20150401 4

Leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) is a pan-ErbB negative regulator and intestinal stem cell marker down-regulated in many malignancies. We previously reported that 14 of 16 Lrig1-CreERT2/CreERT2 (Lrig1(-/-)) mice developed duodenal adenomas, providing the first in vivo evidence that Lrig1 acts as a tumor suppressor. We extended this study to a larger cohort and found that 49 of 54 Lrig1(-/-) mice develop duodenal adenomas beginning at 3 months. Most adenomas were his ...[more]

PMID: 25794708

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Project description:Background and aimsDuodenal polyps have a reported incidence of 0.3% to 4.6%. Sporadic, nonampullary duodenal adenomas (SNDAs) comprise less than 10% of all duodenal polyps, and ampullary adenomas are even less common. Nonetheless, the incidence continues to rise because of widespread endoscopy use. Duodenal polyps with villous features or those that are larger than 10 mm may raise concern for malignancy and require removal. We demonstrate endoscopic resection of SNDAs and ampullary adenomas using some of our preferred techniques.MethodsThe duodenum has several components that can make EMR of duodenal polyps technically challenging. Not only does the duodenum have a thin muscle layer, but it is also highly mobile and vascular, which may explain higher rates of perforation and bleeding of duodenal EMR reported in the literature compared with colon EMR. A standard adult gastroscope with a distal cap is commonly used for duodenal EMRs. Based on the location, however, side-viewing duodenoscopes or pediatric colonoscopes may be used. To prepare for EMR, a submucosal injection is performed for an adequate lift. The polyp is then resected via stiff monofilament snares and subsequently closed with hemostatic clips if feasible. The ampullectomy technique differs slightly from duodenal EMRs and carries the additional risk of pancreatitis. Submucosal injection in the ampulla may not lift well; thus, its utility is debatable. Biliary sphincterotomy should be performed, and based on endoscopist preference, the pancreatic duct (PD) guidewire can be left during resection to maintain access. After resection, a PD stent is placed to minimize pancreatitis risk.ResultsThe video shows the aforementioned duodenal EMR techniques. Two clips of ampullectomy are also shown in the video.ConclusionsA few common techniques used to perform duodenal EMR and ampullectomy are highlighted in the video. It is important to understand and manage adverse events associated with these procedures and to have established surveillance plans.

Project description:Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide and is strongly associated with chronic Helicobacter pylori (Hp) infection. The ability of Hp to closely adhere to the gastric surface protective mucous layer containing mucins (MUC in humans and Muc in animals), primarily Muc5ac, is integral in the stepwise pathogenesis from gastritis to cancer. To probe the role of Muc5ac in Hp-induced gastric pathology, Muc5ac-/- and Muc5ac+/+ (WT) mice were experimentally infected with Hp Sydney strain (SS1). At 16 weeks and 32 weeks post infection (wpi), groups of mice were euthanized and evaluated for the following: gastric histopathological parameters, immunohistochemical expression of mucins (Muc5ac, Muc1, Muc2), Trefoil factor family proteins (Tff1 and Tff2), Griffonia (Bandeiraea) simplicifolia lectin II (GSL II) (mucous metaplasia marker) and Clusterin (Spasmolytic Polypeptide Expressing Metaplasia (SPEM) marker), Hp colonization density by qPCR and gastric cytokine mRNA levels. Our results demonstrate that Muc5ac-/- mice developed spontaneous antro-pyloric proliferation, adenomas and in one case with neuroendocrine differentiation; these findings were independent of Hp infection along with strong expression levels of Tff1, Tff2 and Muc1. Hp-infected Muc5ac-/- mice had significantly lowered gastric corpus mucous metaplasia at 16 wpi and 32 wpi (P = 0.0057 and P = 0.0016, respectively), with a slight reduction in overall gastric corpus pathology. GSII-positive mucous neck cells were decreased in Hp-infected Muc5ac-/- mice compared to WT mice and clusterin positivity was noted within metaplastic glands in both genotypes following Hp infection. Additionally, Hp colonization densities were significantly higher in Muc5ac-/- mice compared to WT at 16 wpi in both sexes (P = 0.05) along with a significant reduction in gastric Tnfα (16 wpi-males and females, P = 0.017 and P = 0.036, respectively and 32 wpi-males only, P = 0.025) and Il-17a (16 wpi-males) (P = 0.025). Taken together, our findings suggest a protective role for MUC5AC/Muc5ac in maintaining gastric antral equilibrium and inhibiting Hp colonization and associated inflammatory pathology.

Dataset Information

Loss of Lrig1 leads to expansion of Brunner glands followed by duodenal adenomas with gastric metaplasia.

Publications

Loss of Lrig1 leads to expansion of Brunner glands followed by duodenal adenomas with gastric metaplasia.

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