To Detach, Migrate, Adhere, and Metastasize: CD97/ADGRE5 in Cancer

Tumorigenesis is a multistep process, during which cells acquire a series of mutations that lead to unrestrained cell growth and proliferation, inhibition of cell differentiation, and evasion of cell death. Growing tumors stimulate angiogenesis, providing them with nutrients and oxygen. Ultimately, tumor cells invade the surrounding tissue and metastasize; a process responsible for about 90% of cancer-related deaths. Adhesion G protein-coupled receptors (aGPCRs) modulate the cellular processes closely related to tumor cell biology, such as adhesion and detachment, migration, polarity, and guidance. Soon after first being described, individual human aGPCRs were found to be involved in tumorigenesis. Twenty-five years ago, CD97/ADGRE5 was discovered to be induced in one of the most severe tumors, dedifferentiated anaplastic thyroid carcinoma. After decades of research, the time has come to review our knowledge of the presence and function of CD97 in cancer. In summary, CD97 is obviously induced or altered in many tumor entities; this has been shown consistently in nearly one hundred published studies. However, its high expression at circulating and tumor-infiltrating immune cells renders the systemic targeting of CD97 in tumors difficult

Perioperative risk factors in patients with a femoral neck fracture – influence of 25-hydroxyvitamin D and C-reactive protein on postoperative medical complications and 1-year mortality

Background: This study examined the association of 25-hydroxyvitamin D (25(OH)D) and C-reactive protein (CRP) with postoperative medical complications and one year mortality of elderly patients sustaining a low-energy cervical hip fracture scheduled for surgery. We hypothesized that vitamin D deficiency and CRP in these patients might be associated with an increased 1-year mortality. Methods: The prospective single-center cohort study included 209 patients with a low-energy medial femoral neck fracture; 164 women aged over 50 years and 45 men aged over 60 years. Referring to 1-year mortality and postoperative medical complications multiple logistic regression analysis including 10 co-variables (age, sex, BMI, ASA, creatinine, CRP, leukocytes hemoglobin, 25(OH)D, vitamin D supplementation at follow-up) was performed. Results: Vitamin D deficiency was prevalent in 87 % of all patients. In patients with severe ( 20 ng/ml 25(OH)D levels (p =0.027). Patients with a mild (CRP 10–39.9 mg/l) or active inflammatory response (CRP ≥ 40 mg/l) showed a higher one year mortality of 33 % and 40 % compared to 16 % in patients with no (CRP < 10 mg/l) inflammatory response (p = 0.002). Multiple logistic regression analysis identified CRP (OR 1.01, 95 % CI 1.00- 1.02; p = 0.007), but not 25(OH)D (OR 0.97, 95 % CI 0.89-1.05; p = 0.425) as an independent predictor for one year mortality. 20 % of patients suffered in-hospital postoperative medical complications (i.e. pneumonia, thromboembolic events, etc.). 25(OH)D (OR 0.89, 95 % CI 0.81–0.97; p = 0.010), but not CRP (OR 1.01, 95 % CI 1.00-1.02; p = 0.139), was identified as an independent risk factor. Conclusion: In elderly patients with low-energy cervical hip fracture, 25(OH)D is independently associated with postoperative medical complications and CRP is an independent predictor of one year mortality

Angiogenic inflammation and formation of necrosis in the tumor microenvironment influence patient survival after radical surgery for de novo hepatocellular carcinoma in non-cirrhosis

BACKGROUND: Tumor escape mechanisms mediated in the tumor microenvironment can significantly reduce the capacity of the anti-tumor function of the immune system. TIE2-expressing monocytes (TEMs), related angiopoietins, and tumor necrosis are considered to have a key role in this process. We aimed to investigate the abundance and clinical significance of these biomarkers in hepatocellular carcinoma (HCC). METHODS: In this retrospective study, 58 HCC patients received surgery with a curative intent. The abundance of TEMs, angiopoietin-1 and -2 were detected in tumor specimens of the HCC patients (n = 58), and together with the occurrence of histologic tumor necrosis, were associated with established clinicopathological characteristics and survival. RESULTS: Patients with HCC characterized by necrosis and TEMs revealed reduced both overall survival and recurrence-free survival (all p < 0.05). Angiopoietins and TEMs were associated with metastatic and recurrent HCC. Furthermore, the formation of histologic tumor necrosis was associated with advanced tumor stage and density of TEMs (all p < 0.05). CONCLUSIONS: Histologic tumor necrosis, TEMs, and related angiopoietins were associated with multiple HCC parameters and patient survival. The tumor necrosis-TEM-angiopoietin axis may offer a novel diagnostic modality to predict patient outcome after surgery for HCC

A Comprehensive Model of the Spatio-Temporal Stem Cell and Tissue Organisation in the Intestinal Crypt

We introduce a novel dynamic model of stem cell and tissue organisation in murine intestinal crypts. Integrating the molecular, cellular and tissue level of description, this model links a broad spectrum of experimental observations encompassing spatially confined cell proliferation, directed cell migration, multiple cell lineage decisions and clonal competition

Transcriptional regulation of the human CD97 promoter by Sp1/Sp3 in smooth muscle cells

The EGF-TM7 receptor CD97 shows different features of expression and function in muscle cells compared to hematopoetic and tumor cells. Since the molecular function and regulation of CD97 are poorly understood, this study aimed at defining its basal transcriptional regulation in smooth muscle cells (SMCs). The computational analysis of the CD97 5′-flanking region revealed that the TATA box-lacking promoter possesses several GC-rich regions as putative Sp1/Sp3 binding sites. Transfection studies with serially deleted promoter constructs demonstrated that the minimal promoter fragment resided in the − 218/+ 45 region containing one out of five identified GC-boxes in the leiomyosarcoma cell line SK-LMS-1 and human bronchial smooth muscle cells (HbSMCs). Mutation of the most proximal GC-site in CD97 reporter gene constructs caused a significant decrease in promoter activity. Gel shift assays and chromatin immunoprecipitation revealed that Sp1 and Sp3 bound specifically to the most proximal GC-site. Furthermore, we showed that Sp1 and Sp3 over-expression activates CD97 promoter activity in HEK293 cells. Our data characterize for the first time the activity of the human CD97 promoter which is controlled by Sp1/Sp3 transcription factors in SMCs

Adhesion GPCR GPR56 Expression Profiling in Human Tissues

Despite the immense functional relevance of GPR56 (gene ADGRG1) in highly diverse (patho)physiological processes such as tumorigenesis, immune regulation, and brain development, little is known about its exact tissue localization. Here, we validated antibodies for GPR56-specific binding using cells with tagged GPR56 or eliminated ADGRG1 in immunotechniques. Using the most suitable antibody, we then established the human GPR56 tissue expression profile. Overall, ADGRG1 RNA-sequencing data of human tissues and GPR56 protein expression correlate very well. In the adult brain especially, microglia are GPR56-positive. Outside the central nervous system, GPR56 is frequently expressed in cuboidal or highly prismatic secreting epithelia. High ADGRG1 mRNA, present in the thyroid, kidney, and placenta is related to elevated GPR56 in thyrocytes, kidney tubules, and the syncytiotrophoblast, respectively. GPR56 often appears in association with secreted proteins such as pepsinogen A in gastric chief cells and insulin in islet β-cells. In summary, GPR56 shows a broad, not cell-type restricted expression in humans

Epigenetic Drifts during Long-Term Intestinal Organoid Culture

Organoids retain the morphological and molecular patterns of their tissue of origin, are self-organizing, relatively simple to handle and accessible to genetic engineering. Thus, they represent an optimal tool for studying the mechanisms of tissue maintenance and aging. Long-term expansion under standard growth conditions, however, is accompanied by changes in the growth pattern and kinetics. As a potential explanation of these alterations, epigenetic drifts in organoid culture have been suggested. Here, we studied histone tri-methylation at lysine 4 (H3K4me3) and 27 (H3K27me3) and transcriptome profiles of intestinal organoids derived from mismatch repair (MMR)-deficient and control mice and cultured for 3 and 20 weeks and compared them with data on their tissue of origin. We found that, besides the expected changes in short-term culture, the organoids showed profound changes in their epigenomes also during the long-term culture. The most prominent were epigenetic gene activation by H3K4me3 recruitment to previously unmodified genes and by H3K27me3 loss from originally bivalent genes. We showed that a long-term culture is linked to broad transcriptional changes that indicate an ongoing maturation and metabolic adaptation process. This process was disturbed in MMR-deficient mice, resulting in endoplasmic reticulum (ER) stress and Wnt activation. Our results can be explained in terms of a mathematical model assuming that epigenetic changes during a long-term culture involve DNA demethylation that ceases if the metabolic adaptation is disturbed

Immunologic cellular characteristics of the tumour microenvironment of hepatocellular carcinoma drive patient outcomes

Background: Anti-tumour immune competence has an impact in hepatocarcinogenesis and success of anti-cancer therapies. Tumour-infiltrating lymphocytes (TILs) and monocytes/macrophages (TAMs) are proposed to have significance in cancer. However, there is only limited data concerning their impact on patient outcome and survival in hepatocellular carcinoma (HCC). Methods: Frequencies of CD68+, CD163+M2-polarized TAMs and TILs were measured in de novo HCC tumours in noncirrhosis (n = 58) using immunohistology and correlated to patients’ clinicopathological characteristics and survival rates. Results: Patients with tumours marked by appearance of TILs and CD68+ TAMs showed an improved 1-, 3- and 5-year recurrence-free survival (all p ≤ 0.05). CD68+ TAMs were associated with reduced incidence of recurrent and multifocal disease. Conversely, CD163+ TAMs were associated with multifocal HCC and lymphangiosis carcinomatosa (all p ≤ 0.05). Conclusions: TILs and CD68+ TAMs are associated with multiple tumour characteristics and patient survival in HCC. However, there is only scarce data about the biology underlying their mechanistic involvement in human tumour progression. Thus, experimental data on functional links might help develop novel immunologic checkpoint inhibitor targets for liver cancer

TIE2-expressing monocytes and M2-polarized macrophages impact survival and correlate with angiogenesis in adenocarcinoma of the pancreas

Introduction: M2-polarized tumor-associated macrophages (TAMs) and TIE2- expressing monocytes (TEMs) are associated with angiogenesis and have been identified as a potential prognostic marker in several solid tumors, including hepatobiliary malignancies. However, little is known regarding their influence on tumor progression and patient survival in pancreatic ductal adenocarcinoma (PDAC). Results: Patients with tumors characterized by the presence of CD163+ TAMs or TEMs in TCA or TIF, respectively, showed a significantly decreased 1-, 3- and 5-year overall and recurrence-free survival compared to patients without CD163+ TAMs or TEMs (all ρ < 0.05). Patients with TEMs in TCA showed a higher incidence of tumor recurrence (ρ < 0.05). Furthermore, the presence of CD163+ TAMs was associated with a higher tumor MVD (ρ < 0.05). Conclusions: Presence of M2-polarized TAMs and TEMs is associated with a decreased overall and recurrence-free survival of patients with PDAC. Materials and methods: The localization and density of CD163+ M2-polarized TAMs and TEMs were quantified in the tumor central area (TCA) and tumor-infiltrating front (TIF) in human PDAC tissue (n = 106) and correlated to clinicopathological characteristics, tumor recurrence rates and patient survival. In parallel, tumor microvascular density (MVD) and the density of angiopoietin-positive tumor cells were quantified. Statistical analysis was performed using SPSS software

Mechano-Dependent Phosphorylation of the PDZ-Binding Motif of CD97/ADGRE5 Modulates Cellular Detachment

Summary Cells respond to mechanical stimuli with altered signaling networks. Here, we show that mechanical forces rapidly induce phosphorylation of CD97/ADGRE5 (pCD97) at its intracellular C-terminal PDZ-binding motif (PBM). Biochemically, this phosphorylation disrupts CD97 binding to PDZ domains of the scaffold protein DLG1. In shear-stressed cells, pCD97 appears not only in junctions, retracting fibers, and the attachment area but also in lost membrane patches, demonstrating (intra)cellular detachment at the CD97 PBM. This motif is critical for the CD97-dependent mechanoresponse. Cells expressing CD97 without the PBM are more deformable, and under shear stress, these cells lose cell contacts faster and show changes in the actin cytoskeleton when compared with cells expressing full-length CD97. Our data indicate CD97 linkage to the cytoskeleton. Consistently, CD97 knockout phenocopies CD97 without the PBM, and membranous CD97 is organized in an F-actin-dependent manner. In summary, CD97 shapes the cellular mechanoresponse through signaling modulation via its PBM