Contribution of Interstitial Cells of Cajal to Gastrointestinal Stromal Tumor Risk

Case report: Clinical and molecular features of renal gastrointestinal tumor

While gastrointestinal stromal tumors (GISTs) often arise within the GI tract, it is well known that GISTs may also rarely emanate outside of the digestive system. Prior case reports have documented various primary sites in non-GI organs [extra-intestinal GIST (EGIST)], yet only one report has described a localized GIST of renal origin. Here, we describe a patient who presented with bilateral renal masses who was found to have a large unresectable renal GIST tumor treated with imatinib. We discuss treatment experience and response with systemic therapy and describe molecular data to contextualize this ultra-rare presentation within the landscape of EGIST tumors.

Exploring the heterogeneity of interstitial cells of Cajal and their properties in gastrointestinal mesenchymal tumors applying single-cell RNA sequencing analysis

BACKGROUND

Gastrointestinal mesenchymal stromal tumors (GISTs) are a group of intramural tumors that exhibit a wide range of morphologies. Dysfunction or loss of interstitial cells of Cajal (ICCs) is correlated with the disorders of gastrointestinal motility. At present, the characterization and molecular mechanisms underlying the role of ICCs in GIST are still not clear.

METHODS

The GSE162115 dataset from Gene Expression Omnibus database was processed using Seurat package for quality control, data normalization, and cell clustering. Differential expression and functional enrichment analyses were performed using the FindAllMarkers function and clusterProfiler package. Cellular heterogeneity was assessed by CytoTRACE and potential regulatory mechanisms of ICCs in GISTs were investigated using SCENIC. Cellular communication was inferred and analyzed applying the CellChat package.

RESULTS

Eight clusters were identified based on 34,861 cells. Intra-tumor samples had a higher proportion of ICCs than peri-tumor. ICCs were related to cell cycle and glycolytic activity in intra-tumor samples, while those in peri-tumor samples were involved in immune response. Further analysis identified four ICC subgroups (subcluster 1-4), of which subcluster 3 showed the most typical stem cell properties and interacted with the rest of the cells through the MIF-CD74 (CD44) protein.

CONCLUSION

This study analyzed the heterogeneity and stem cell properties of ICCs in GISTs, revealing the molecular mechanisms and potential therapeutic targets for GISTs.

Role of CD34 in inflammatory bowel disease

Inflammatory bowel disease (IBD) is caused by a variety of pathogenic factors, including chronic recurrent inflammation of the ileum, rectum, and colon. Immune cells and adhesion molecules play an important role in the course of the disease, which is actually an autoimmune disease. During IBD, CD34 is involved in mediating the migration of a variety of immune cells (neutrophils, eosinophils, and mast cells) to the inflammatory site, and its interaction with various adhesion molecules is involved in the occurrence and development of IBD. Although the function of CD34 as a partial cell marker is well known, little is known on its role in IBD. Therefore, this article describes the structure and biological function of CD34, as well as on its potential mechanism in the development of IBD.

GIST and Ghrelin: To Be or Not to Be?

BACKGROUND

Ghrelin is the orexigenic hormone secreted mainly by the stomach. Its involvement in neoplastic development has been studied in gastrointestinal adenocarcinomas. Our paper aims to evaluate the influence of the ghrelin axis in gastrointestinal stromal tumors (GISTs).

MATERIALS AND METHODS

The study design included two groups of patients, 46 with gastric GISTs and 30 with obesity. Archived tissue samples were evaluated for the presence of gastritis and H. pylori. Immunohistochemical expression of ghrelin and its receptor (GHS-R) was assessed.

RESULTS

All GISTs showed absent immunohistochemical expression for ghrelin, while GHS-R displayed a particular pattern, with notable differences in intensity (p = 0.0256) and percentage of stained cells (p < 0.00001) in the periphery vs. core of tumors. Positive ghrelin expression was lower in the gastric mucosa of the first group compared to the second group (p < 0.001).

CONCLUSION

The ghrelin axis can influence GISTs carcinogenesis through activation of GHS-R. A previously described direct autocrine/paracrine mechanism is not supported by our findings.