Discoidin Domain Receptor 1 Expression Research Articles

Abstract A033: Integrating spatial transcriptomics and second harmonic generation imaging to identify targets of supermere-associated Discoidin Domain Receptor 1 involved in collagen alignment

Abstract Immune checkpoint blockade has been shown to be an effective treatment for colorectal cancers (CRCs) highly infiltrated by CD8+ T cells. However, there is a paucity of CD8+ T-cell infiltration in the majority of CRCs. We previously identified the collagen-activated receptor Discoidin Domain Receptor 1 (DDR1) as a member of a four-gene signature associated with T-cell exclusion in CRC. The cleaved ectodomain (cECD) of DDR1 induces collagen alignment, leading to T-cell exclusion in a breast cancer model. We found that almost all DDR1 cECD is found in supermeres, a novel secreted nanoparticle identified by our lab, and that DDR1 cECD is required for supermere signaling in recipient cells. We hypothesized that supermere-associated DDR1 cECD signals to CRC stromal cells, leading to collagen alignment. To test this hypothesis, we developed a method to determine which genes are associated with collagen alignment and DDR1 expression. To do this, 30 μm thick CRC sections are imaged using a Nikon AX multiphoton microscope by second harmonic generation imaging, which permits label-free imaging of collagen fibers. Spatial heatmaps of the collagen alignment are generated from the resulting images. Spatial transcriptomics is performed on a serial tumor section using the Visium v2 platform and the gene expression matrix is integrated with the collagen alignment heatmap data. As proof-of-principle, two CRC tumors have been analyzed using this method. Highly aligned regions were found to be associated with expression of genes involved in extracellular matrix organization, keloidal collagen and specific fibroblast subtypes. Genes which may be regulated by DDR1 cECD and be involved in collagen alignment will be confirmed at the protein level by multiplexed immunofluorescence on serial sections and in vitro experiments. This method will provide a rich dataset to elucidate the roles of supermeres and DDR1 cECD in T-cell exclusion and collagen fiber alignment and may support the discovery of new strategies to overcome immune exclusion in CRC. Citation Format: Maxwell S. Hamilton, Oleg Tutanov, Harsimran Kaur, Alan J. Simmons, Clark Massick, Kasey Vickers, Ken S. Lau, Ambra Pozzi, Robert J. Coffey. Integrating spatial transcriptomics and second harmonic generation imaging to identify targets of supermere-associated Discoidin Domain Receptor 1 involved in collagen alignment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A033.

Super-resolution imaging reveals the role of DDR1 cluster in NSCLC proliferation

Discoidin domain receptor 1 (DDR1), a transmembrane protein, is crucial in tumor development. Prior studies have demonstrated a significant correlation between protein cluster distribution on the cell membrane and tumor evolution. However, the precise spatial distribution characteristics of DDR1 on cell membranes and their impact on tumor development remain unclear. In this study, we conducted gene expression analysis to investigate DDR1 expression in non-small cell lung cancer (NSCLC) and its association with patient prognosis. We also employed direct stochastic optical reconstruction microscopy (dSTORM) imaging to examine DDR1's spatial distribution in NSCLC cells and tissues. Our findings indicate that DDR1 forms larger, tighter, and more abundant clusters in cancer cells and tissues compared to their normal counterparts. Notably, we observed that the enhanced aggregation of DDR1 clusters increased the likelihood of interaction with SRC, thereby activating the SRC-STAT3 signaling pathway in NSCLC cells and promoting cell proliferation. This study provides novel insights into the role of DDR1 aggregation in tumor proliferation, confirms DDR1 as a potential tumor marker, and serves as a valuable resource for future drug development.

Codon Bias of the DDR1 Gene and Transcription Factor EHF in Multiple Species.

Milk production is an essential economic trait in cattle, and understanding the genetic regulation of this trait can enhance breeding strategies. The discoidin domain receptor 1 (DDR1) gene has been identified as a key candidate gene that influences milk production, and ETS homologous factor (EHF) is recognized as a critical transcription factor that regulates DDR1 expression. Codon usage bias, which affects gene expression and protein function, has not been fully explored in cattle. This study aims to examine the codon usage bias of DDR1 and EHF transcription factors to understand their roles in dairy production traits. Data from 24 species revealed that both DDR1 and EHF predominantly used G/C-ending codons, with the GC3 content averaging 75.49% for DDR1 and 61.72% for EHF. Synonymous codon usage analysis identified high-frequency codons for both DDR1 and EHF, with 17 codons common to both genes. Correlation analysis indicated a negative relationship between the effective number of codons and codon adaptation index for both DDR1 and EHF. Phylogenetic and clustering analyses revealed similar codon usage patterns among closely related species. These findings suggest that EHF plays a crucial role in regulating DDR1 expression, offering new insights into genetically regulating milk production in cattle.

Antibody-drug conjugates targeting DDR1 as a novel strategy for treatment of breast cancer

Antibody-drug conjugates (ADCs) have emerged as a novel class of targeted cancer therapies and been successfully applied in the treatment of breast cancer (BC). Discoidin domain receptor 1 (DDR1) is a single transmembrane receptor tyrosine kinase and has been identified as a possible target for cancer. In this study, we explored the potential of an anti-DDR1 ADC, named T4H11-DM4, for the treatment of DDR1-positive BC. We demonstrated that high protein expression and RNA expression of DDR1 in BC tissues. In vitro, T4H11-DM4 was potently cytotoxic to DDR1-expressing BC cells, with IC50 in the nanomolar range. In mice BC xenograft models, T4H11-DM4 dramatically eliminated BC tumours, without observable toxicity. Taken together, our findings demonstrated that DDR1 can serve as a promising therapeutic target for BC.

Abstract 2916: Discoidin domain receptor 1 (DDR1) expression is associated with degree of immune exclusion across epithelial tumors

Abstract Background: Discoidin domain receptor 1 (DDR1) is highly expressed in epithelial cancers and has been implicated in tumor growth, invasion, and lack of response to therapy. DDR1 contributes to immune exclusion by promoting tumor collagen alignment in in vivo models. However, it is unclear how DDR1 expression impacts immune cell infiltration in human tumors. A first-in-human trial of PRTH-101, a DDR1-targeted therapeutic antibody, is underway. Establishing a correlation between DDR1 expression and immune infiltration in the tumor microenvironment (TME) will shed light on the role of DDR1 in the TME and inform indication and patient selection strategies for DDR1-targeted therapies. Methods: Adjacent formalin fixed paraffin embedded slides from colorectal (CRC), non-small cell lung (NSCLC), ovarian (OC), pancreatic (PDAC), and triple-negative breast cancers (TNBC) were stained by H&E and a multiplex immunofluorescence (mIF) panel containing DDR1 and immune cell markers CD8 and CD45. Tumor-stromal segmentation and cell identification was done from H&E using AI-powered models developed by PathAI (PathExplore™) or from mIF by image analysis using QuPath. DDR1 mRNA expression was measured by bulk RNA-sequencing, while DDR1 protein expression was measured by mIF. Immune Exclusion Scores (IESs) were calculated for each tumor based on lymphocyte density (from H&E), CD8+ T cell density (from mIF), or CD45+ cell density (from mIF). Each IES is the orthogonal distance between the coordinate of immune cell density in tumor epithelium and stroma, and the regression line representing equal density in epithelium and stroma. Correlations between lymphocyte, CD8, and CD45 IESs and DDR1 mRNA or protein expression levels were evaluated. Results: Both DDR1 mRNA and protein expression levels were significantly correlated with all Immune Exclusion Scores (IESs) measured by the distribution of lymphocytes (H&E), CD8+, or CD45+ cells (mIF) in tumor epithelium and stroma (R: 0.31-0.55, adjusted p: <0.001-0.01) at a pan-cancer level. While the degree of the correlation varied between tumor indications by IES immune cell type, pancreatic cancer exhibited the strongest correlation between the lymphocyte-based IES and DDR1 mRNA and protein expression (R: 0.48-0.54, adjusted p: 0.04-0.07). DDR1 mRNA was also moderately correlated with lymphocyte IES in NSCLC and TNBC (R: 0.37-0.48, adjusted p: 0.12-0.14). Conclusions: We developed a continuous scoring method to quantify the degree of immune exclusion in tumors based on the spatial distributions of lymphocytes, CD8+ T cells, and CD45+ immune cells from H&E and mIF images. DDR1 mRNA and protein expression are correlated with immune exclusion at both the pan-cancer and specific indication level. This adds additional insight into the role of DDR1 in human cancers and may be useful in selecting indications and stratifying patients for DDR1-targeted therapies. Citation Format: Xinwei Sher, Fredrick D. Gootkind, Thomas Schürpf, Florent Peyraud, Jean-Philippe Guégan, Antoine Italiano, G. Travis Clifton, Laura A. Dillon. Discoidin domain receptor 1 (DDR1) expression is associated with degree of immune exclusion across epithelial tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2916.

Altered Treg Infiltration after Discoidin Domain Receptor 1 (DDR1) Inhibition and Knockout Promotes Tumor Growth in Lung Adenocarcinoma.

Lung cancer is the leading cause of cancer-related death worldwide. Discoidin domain receptor 1 (DDR1), a tyrosine kinase receptor, has been associated with poor prognosis in patients with non-small cell lung cancer (NSCLC). However, its role in tumorigenesis remains poorly understood. This work aimed to explore the impact of DDR1 expression on immune cell infiltration in lung adenocarcinoma. Pharmacological inhibition and knockout of DDR1 were used in an immunocompetent mouse model of KRAS/p53-driven lung adenocarcinoma (LUAD). Tumor cells were engrafted subcutaneously, after which tumors were harvested for investigation of immune cell composition via flow cytometry. The Cancer Genome Atlas (TCGA) cohort was used to perform gene expression analysis of 509 patients with LUAD. Pharmacological inhibition and knockout of DDR1 increased the tumor burden, with DDR1 knockout tumors showing a decrease in CD8+ cytotoxic T cells and an increase in CD4+ helper T cells and regulatory T cells. TCGA analysis revealed that low-DDR1-expressing tumors showed higher FoxP3 (regulatory T-cell marker) expression than high-DDR1-expressing tumors. Our study showed that under certain conditions, the inhibition of DDR1, a potential therapeutic target in cancer treatment, might have negative effects, such as inducing a pro-tumorigenic tumor microenvironment. As such, further investigations are necessary.

Prognostic significance of TM4SF1 and DDR1 expression in epithelial ovarian cancer.

Transmembrane 4 L6 family member 1 (TM4SF1) and discoidin domain receptor 1 (DDR1) are expressed in numerous types of cancer, but their expression in epithelial ovarian cancer and the association between their expression and patient prognosis are unclear. The present study aimed to explore the expression of TM4SF1 and DDR1 and their relationship with prognosis in epithelial ovarian cancer. Firstly, the Oncomine and Gene Expression Profiling Interactive Analysis (GEPIA) platforms were used to compare the expression levels of TM4SF1 and DDR1 in ovarian cancer and normal ovarian tissue, and Kaplan-Meier plotter was used to analyze the association between gene expression and patient prognosis. The proteins interacting with TM4SF1 and DDR1 were analyzed using Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), and enrichment analysis of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways was conducted for the interacting proteins. Furthermore, immunohistochemical staining was performed to detect the expression of TM4SF1 and DDR1 protein in epithelial ovarian cancer tissue and to analyze the association between expression and prognosis. The Oncomine and GEPIA analyses showed that the expression levels of TM4SF1 and DDR1 were significantly higher in epithelial ovarian cancer than in normal ovarian tissue, and the analysis of clinical samples revealed that TM4SF1 and DDR1 were coexpressed in some cases. STRING analysis indicated that the TM4SF1 and DDR1 proteins interact with each other. The overall survival and progression-free survival of patients whose epithelial ovarian cancer coexpressed TM4SF1 and DDR1 were significantly shorter than those of patients lacking TM4SF1 and DDR1 coexpression. Multivariate analysis indicated that TM4SF1 and DDR1 protein coexpression was an independent prognostic factor. In summary, TM4SF1 and DDR1 proteins were coexpressed in some epithelial ovarian cancer tissues and appear to be adverse prognostic factors for epithelial ovarian cancer. In addition, TM4SF1 and DDR1 may have an interactive or mutual regulatory mechanism.

DDR1 and Its Ligand, Collagen IV, Are Involved in In Vitro Oligodendrocyte Maturation

Discoidin domain receptor 1 (DDR1) is a tyrosine kinase receptor expressed in epithelial cells from different tissues in which collagen binding activates pleiotropic functions. In the brain, DDR1 is mainly expressed in oligodendrocytes (OLs), the function of which is unclear. Whether collagen can activate DDR1 in OLs has not been studied. Here, we assessed the expression of DDR1 during in vitro OL differentiation, including collagen IV incubation, and the capability of collagen IV to induce DDR1 phosphorylation. Experiments were performed using two in vitro models of OL differentiation: OLs derived from adult rat neural stem cells (NSCs) and the HOG16 human oligodendroglial cell line. Immunocytofluorescence, western blotting, and ELISA were performed to analyze these questions. The differentiation of OLs from NSCs was addressed using oligodendrocyte transcription factor 2 (Olig2) and myelin basic protein (MBP). In HOG16 OLs, collagen IV induced DDR1 phosphorylation through slow and sustained kinetics. In NSC-derived OLs, DDR1 was found in a high proportion of differentiating cells (MBP+/Olig2+), but its protein expression was decreased in later stages. The addition of collagen IV did not change the number of DDR1+/MBP+ cells but did accelerate OL branching. Here, we provide the first demonstration that collagen IV mediates the phosphorylation of DDR1 in HOG16 cells and that the in vitro co-expression of DDR1 and MBP is associated with accelerated branching during the differentiation of primary OLs.

The influence of discoidin domain receptor 1 expression on angiogenic factors: VEGF-A and FGF-2 in non-small cell lung cancer

ObjectivesLung cancer is responsible for more cancer-related death worldwide. Most lung cancer patients have non-small cell lung cancers (NSCLC), with a low survival rate. Therefore, it is necessary to study new and effective targeted therapies. Discoidin domain receptor 1 (DDR1) is a tyrosine kinase receptor that can be promoted by collagen type I, and dysregulation of DDR1 signaling is involved in several phases of tumorigenesis. Tumor growth and metastasis depend on angiogenesis caused by angiogenic factors, such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) secreted by tumor cells. Thus, angiogenesis plays a critical role in cancer progression. The current study amid to evaluate the expression alteration of DDR1 and its effects on angiogenic factors VEGF-A, FGF-1, and FGF2 in NSCLC. Materials and methodsA549 and Calu-3 cells were treated with collagen type I and transfected with DDR1 small interfering RNA (siRNA). Then, the relative expression of DDR1, VEGF-A, FGF-1, and FGF-2 of cells was evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). The concentration of angiogenic factors was calculated by the Human Angiogenesis 17-plex discovery assay. ResultsAccording to our data, collagen type I could stimulate DDR1 expression in A549 and Calu-3 cells, and DDR1 upregulation resulted in a significant increase of VEGF-A and FGF-2 expression, but did not induce FGF-1 expression. Moreover, suppression of DDR1 expression could significantly decrease VEGF-A and FGF-2 expression. Conclusionour findings suggest that alteration of DDR1 expression mediated by collagen I and siRNA may affect VEGF-A and FGF-2 expression in non-small cell lung cancer associated with tumor angiogenesis and represent a new treatment approach.

Discoidin domain receptor 1(DDR1) promote intestinal barrier disruption in Ulcerative Colitis through tight junction proteins degradation and epithelium apoptosis

Background and aimsDiscoidin domain receptor 1 (DDR1) encodes a receptor tyrosine kinase involved in multiple physiological and pathological processes. DDR1 is expressed in the intestinal epithelium, but its role in Ulcerative Colitis (UC) is poorly understand. This study aimed to identify the function of DDR1 in maintaining the homeostasis of UC. MethodsThe DDR1 expression level in non-inflamed and inflamed colon samples from IBD patients were assessed. DDR1 knock-out (DDR1-/-) and wild-type (WT) mice were administered dextran sulfate sodium (DSS) to induce colitis and assessed based on colitis symptoms. In addition, intestinal epithelial barrier injury was induced by TNF-α and IFN-γ incubation to cell monolayers transfected with PCDH-DDR1 or pLKO.1-sh-DDR1–1 plasmids. The effect of DDR1 in regulating barrier integrity, tight junctions (TJ) protein status, and cell apoptosis was investigated in vivo and in vitro. Furthermore, the activation of the NF-κB p65-MLCK-p-MLC2 pathway was also investigated. ResultsDecreased DDR1 expression levels were observed at the inflamed sites compared with the non-inflamed. DDR1-/- mice had alleviated intestinal mucosal barrier injuries, upregulated TJ proteins, decreased epithelium apoptosis from DSS-induced colitis, and reduced proinflammatory cytokines production in the colon. These findings were further confirmed in vitro. DDR1 over-expression aggravated the TNF-α/IFN-γ-induced TJ disruption, while DDR1 shRNA prevented TJ damage even in the presence of JSH-23. DDR1 dependently destroyed the intestinal barrier via the NF-κB p65-MLCK-p-MLC2 pathway. ConclusionOur findings revealed that DDR1 regulated the intestinal barrier in colitis by modulating TJ proteins expression and epithelium apoptosis, making it a potential target of UC.

Discoidin domain receptor 1 is a potential target correlated with tumor invasion and immune infiltration in gastric cancer.

Discoidin domain receptor 1 (DDR1) has been demonstrated to be able to promote tumor invasion and metastasis and being closely related to tumor immune infiltration. However, DDR1 has rarely been studied in gastric cancer. Here, we primarily evaluated DDR1 expression in gastric cancer and its cell lines using multiple databases. Subsequently, the cancer prognosis was investigated in relation to DDR1 expression. After analysis, we discovered that DDR1 was highly expressed and significantly connected with poor prognosis in gastric cancer. To comprehensively understand the molecular mechanism of DDR1, we explored genes and proteins interacting with DDR1 in gastric cancer using databases. Additionally, we found that the expression level of DDR1 was inversely correlated with immune infiltration and significantly relative to various immune cell markers. Overall, DDR1 was implicated in invasion, metastasis, and immune infiltration of gastric cancer. Inhibition of DDR1 may have the potential to alleviate the strong invasiveness and metastasis of advanced gastric cancer. Meanwhile, immune exclusion by DDR1 may also provide a new strategy for improving the efficacy of immune checkpoints inhibitors (ICIs), such as programmed cell death protein 1 (PD-1) antibody.

Association of DDR1 with immune exclusion and outcomes in non-small cell lung cancer.

e20553 Background: Discoidin domain receptor 1 (DDR1) is a collagen receptor with tyrosine kinase activity. Although DDR1 has been reported to implicated in cancer progression and metastases, the underlying mechanism remains poorly characterized and its prognostic value is also contradictory in non-small cell lung cancer (NSCLC). Methods: Clinical and DDR1 mRNA expression data of 1925 patients with NSCLC were obtained from 14 publicly available datasets utilizing an online tool KM-plotter. All patients were split into 2 groups by median expression of DDR1. The Kaplan-Meier curve and log-rank test, and Cox regression analyses were used to examine the association between DDR1 expression and overall survival (OS). The table shows 48 immune-regulatory genes classified into 4 signatures associated with activated T cells, immune cytolytic activity, and antitumor immunity. Expression data of these genes for 994 patients with NSCLC were gathered from the TCGA Pan-Cancer Atlas. Abundance data of various immune cell types in tumor microenvironment for the TCGA patients were inferred using xCell, and then immune infiltration extent was calculated as immune score. Associations of DDR1 with immune genes expression and immune score were determined with Spearman rank correlation. Results: DDR1 overexpression was significantly associated with inferior OS in this large-scale cohort (median, 62 vs 78.5 months; hazard ratio [HR], 1.16; 95% CI, 1.02-1.31; P = .02). Of note, multivariable Cox model indicated DDR1 overexpression was an independent risk factor for OS (HR, 1.41; 95% CI, 1.01-1.98; P = .046), controlling for potential confounders (histology, stage, sex, and smoking history). Of the 48 immune-regulatory genes, 44 (92%) showed significant negative correlations with DDR1 expression (all P < .05), implying the role of DDR1 in decreasing immune infiltration into tumor microenvironment. Further, higher immune score was observed in tumors underexpressing DDR1 (correlation coefficient, -0.44; P < .001), more directly demonstrating the link between DDR1 and immune infiltration. Conclusions: To our knowledge, this is the largest study to evaluate the prognostic role of DDR1 expression in NSCLC. Our results suggest that DDR1 overexpression may predict poor outcomes and a possible mechanistic explanation regarding this role may be immune exclusion instigated by DDR1. Thus, targeting DDR1 expression to abrogate immune exclusion warrants further investigation.[Table: see text]

Discoidin domain receptor 1 promotes lung adenocarcinoma migration via the AKT/snail signaling axis.

Discoidin domain receptor 1 (DDR1), a member of receptor tyrosine kinase, has been implicated in tumor progression. However, the function and underlying mechanism of DDR1 in lung adenocarcinoma (LUAD) progression is unclear. Thus, we explored the molecular regulatory mechanism of DDR1 in the migration of LUAD. Transwell assays, wound healing assays and xenograft tumor assays were performed to study the function of DDR1 in the progression of LUAD. Immunoblotting and quantitative real-time polymerase chain reaction (RT-qPCR) were used to detect the expression levels of genes. Co-immunoprecipitation (co-IP) assays were performed to detect the interaction between DDR1 and AKT. Immunofluorescence and immunohistochemistry assays were used to determine the expression level of proteins in cells and tissues, respectively. DDR1 expression was significantly higher in LUAD tissues than in normal lung tissues, and the level of DDR1 was inversely correlated with prognosis in patients. We found that DDR1 promoted the migration and invasion of LUAD cells in vitro. Furthermore, ectopic expression of DDR1 in LUAD cells altered EMT-related markers expression. Importantly, the DDR1 protein interacted with AKT and phosphorylated AKT. The AKT inhibitor MK2206 interrupted Snail upregulation in DDR1-overexpressing LUAD cells. Finally, our study revealed that depletion of DDR1 attenuated LUAD cell migration in a tumor xenograft mouse model. Our findings uncovered that a high abundance of DDR1 increased the migration and invasion capability of LUAD cells via the AKT/Snail signaling axis and indicated that DDR1 could be a potential target for treating LUAD.

Stiffness-responsive feedback autoregulation of DDR1 expression is mediated by a DDR1-YAP/TAZ axis

Objective: Increased matrix stiffness is sensed by the collagen-binding receptor tyrosine kinase discoidin domain receptor 1 (DDR1). We have previously shown that DDR1 stimulates a positive feedback loop to increase its own expression in vascular smooth muscle cells (VSMCs). The transcriptional co-factors YAP/TAZ are stiffness sensing molecules that have not previously been investigated in DDR1 signaling. Here, we test the hypothesis that DDR1 signals through YAP/TAZ to auto-regulate its own expression.Approach and Results: We used vascular smooth muscle cells (VSMCs) from wild-type and DDR1 knockout mice stimulated with collagen and/or substrates of different stiffness. We show that DDR1 controls YAP/TAZ nuclear localization and activity, whereas knockdown of YAP/TAZ attenuates DDR1 expression. In response to increased substrate stiffness, collagen stimulation, or RhoA activation, YAP/TAZ translocate to the nucleus and bind to chromatin. Finally, collagen stimulation promotes increased YAP/TAZ association with the Ddr1 promoter.Conclusions: These findings reveal the mechanism by which DDR1 regulates YAP/TAZ activity which can then mediate positive feedback regulation of DDR1 expression by promoting transcription of the DDR1 gene.

Effects of DDR1 on migration and adhesion of periodontal ligament cells and the underlying mechanism.

As one of the widely expressed cell surface receptors binding to collagen, the most abundant component of the extracellular matrix (ECM), knowledge of the expression, functions, and mechanisms underlying the role of discoidin domain receptor 1 (DDR1) in human periodontal ligament cells (hPDLCs) is incomplete. This study determined the expression of DDR1 in hPDLCs and the effect of DDR1 upon migration and adhesion to hPDLCs, as well as the related regulatory mechanisms. The expression of DDR1 and the DDR1 isoforms in hPDLCs from six donors were tested. The migratory ability (horizontal and vertical) and adhesive capacity of hPDLCs with or without specific knockdown of DDR1 were evaluated. After treatment with MEK-ERK1/2 inhibitors (PD98059 and U0126) with or without RNAi, the migratory and adhesive capacity of hPDLCs were re-tested. Western blotting was performed to verify p-MEK1/2 and p-ERK1/2, the key factors of the MEK-ERK1/2 signaling pathways. DDR1 was detected in hPDLCs in the mRNA and protein level; DDR1b was the dominant isoform. Knockdown of DDR1 almost halved the migratory capacity and significantly downregulated the adhesive capacity of hPDLCs. The use of MEK-ERK1/2 inhibitors caused declined migratory and adhesive capacity of hPDLCs as well. After DDR1 was knocked down, the expression of p-MEK and p-ERK protein declined significantly while total MEK and ERK showed no obvious change, which means the ratio of p-MEK/MEK and p-ERK/ERK was markedly reduced. DDR1 plays an important role in the migration and adhesion of hPDLCs and might be regulated via the MEK-ERK1/2signaling pathway.

Discoidin domain receptor 1 as a promising biomarker for high-grade gliomas.

Two fundamental challenges in the current therapeutic approach for central nervous system tumors are the tumor heterogeneity and the absence of specific treatments and biomarkers that selectively target the tumor tissue. Therefore, we aimed to investigate the potential relationship between discoidin domain receptor 1 (DDR1) expression and the prognosis and characteristics of glioma patients. Tissue and serum samples from 34 brain tumor patients were evaluated for DDR1 messenger ribonucleic acid levels in comparison to 10 samples from the control group, and Kaplan-Meier survival analysis has performed. DDR1 expression was observed in both tissue and serum samples of the patient and control groups. DDR1 expression levels in tissue and serum samples from patients were higher in comparison to the control group, although not statistically significant (P > 0.05). A significant correlation between tumor size and DDR1 serum measurements at the level of 0.370 was reported (r = 0.370; P = 0.034). The levels of DDR1 in serum showed a positive correlation with the increasing size of tumor. The results of the 5-year survival analysis depending on the DDR1 tissue levels showed a significantly higher survival rate (P = 0.041) for patients who have DDR1 tissue levels above cutoff value. DDR1 expression was significantly higher among brain tumor tissues and serum samples and its levels showed a positive correlation with the increased size of tumor. This study can be a starting point, since it investigated and indicated, for the first time, that DDR1 can be a novel therapeutic and prognostic target for aggressive high-grade gliomas.

Discoidin Domain Receptor 1 Expression in Colon Cancer: Roles and Prognosis Impact.

Simple SummaryColorectal cancer (CRC) is the third leading cause of cancer death in both sexes. Identification of the influencing factors and molecular mechanisms in CRC progression could improve patient survival. This study aimed first to characterize the expression of Discoidin Domain Receptor 1 (DDR1), a receptor tyrosine kinase for collagens in a large cohort of CRC patients, and second to establish in vitro whether DDR1 expression level is linked to CRC aggressiveness potential. Our immunohistochemical study indicated that DDR1 is highly expressed in colon cancer compared to normal colonic mucosa and its expression is associated with shorter event-free survival. In vitro, the invasive properties of several CRC cell lines seem to be correlated with the expression level of DDR1. Taken altogether, our results show that DDR1 is highly expressed in most colon adenocarcinomas and appears as an indicator of worse event free survival.Extracellular matrix components such as collagens are deposited within the tumor microenvironment at primary and metastatic sites and are recognized to be critical during tumor progression and metastasis development. This study aimed to evaluate the clinical and prognostic impact of Discoidin Domain Receptor 1 (DDR1) expression in colon cancers and its association with a particular molecular and/or morphological profile and to evaluate its potential role as a prognosis biomarker. Immunohistochemical expression of DDR1 was evaluated on 292 colonic adenocarcinomas. DDR1 was highly expressed in 240 (82.2%) adenocarcinomas. High DDR1 immunostaining score was significantly associated, on univariate analysis, with male sex, left tumor location, BRAF wild type status, KRAS mutated status, and Annexin A10 negativity. High DDR1 immunohistochemical expression was associated with shorter event free survival only. Laser capture microdissection analyses revealed that DDR1 mRNA expression was mainly attributable to adenocarcinoma compared to stromal cells. The impact of DDR1 expression on cell invasion was then evaluated by modified Boyden chamber assay using cell types with distinct mutational profiles. The invasion capacity of colon adenocarcinoma is supported by DDR1 expression. Thus, our results showed that DDR1 was highly expressed in most colon adenocarcinomas and appears as an indicator of worse event free survival.

DDR1 associates with TRPV4 in cell-matrix adhesions to enable calcium-regulated myosin activity and collagen compaction.

Tissue fibrosis manifests as excessive deposition of compacted, highly aligned collagen fibrils, which interfere with organ structure and function. Cells in collagen-rich lesions often exhibit marked overexpression of discoidin domain receptor 1 (DDR1), which is linked to increased collagen compaction through the association of DDR1 with the Ca2+ -dependent nonmuscle myosin IIA (NMIIA). We examined the functional relationship between DDR1 and the transient receptor potential vanilloid type 4 (TRPV4) channel, a Ca2+ -permeable ion channel that is implicated in collagen compaction. Fibroblasts expressing high levels of DDR1 were used to model cells in lesions with collagen compaction. In these cells, the expression of the β1 integrin was deleted to simplify studies of DDR1 function. Compared with DDR1 wild-type cells, high DDR1 expression was associated with increased Ca2+ influx through TRPV4, enrichment of TRPV4 in collagen adhesions, and enhanced contractile activity mediated by NMIIA. At cell adhesion sites to collagen, DDR1 associated with TRPV4, which enhanced DDR1-mediated collagen alignment and compaction. We conclude that DDR1 regulates Ca2+ influx through the TRPV4 channel to promote critical, DDR1-mediated processes that are important in lesions with collagen compaction and alignment.

DDR1 promotes hepatocellular carcinoma metastasis through recruiting PSD4 to ARF6

Discoidin domain receptor 1 (DDR1) is a member of the receptor tyrosine kinase family, and its ligand is collagen. Previous studies demonstrated that DDR1 is highly expressed in many tumors. However, its role in hepatocellular carcinoma (HCC) remains obscure. In this study, we found that DDR1 was upregulated in HCC tissues, and the expression of DDR1 in TNM stage II-IV was higher than that in TNM stage I in HCC tissues, and high DDR1 expression was associated with poor prognosis. Gene expression analysis showed that DDR1 target genes were functionally involved in HCC metastasis. DDR1 positively regulated the migration and invasion of HCC cells and promoted lung metastasis. Human Phospho-Kinase Array showed that DDR1 activated ERK/MAPK signaling pathway. Mechanically, DDR1 interacted with ARF6 and activated ARF6 through recruiting PSD4. The kinase activity of DDR1 was required for ARF6 activation and its role in metastasis. High expression of PSD4 was associated with poor prognosis in HCC. In summary, our findings indicate that DDR1 promotes HCC metastasis through collagen induced DDR1 signaling mediated PSD4/ARF6 signaling, suggesting that DDR1 and ARF6 may serve as novel prognostic biomarkers and therapeutic targets for metastatic HCC.

Collagen and Discoidin Domain Receptor 1 Partnership: A Multifaceted Role in the Regulation of Breast Carcinoma Cell Phenotype.

Type I collagen, the major components of breast interstitial stroma, is able to regulate breast carcinoma cell behavior. Discoidin domain receptor 1 (DDR1) is a type I collagen receptor playing a key role in this process. In fact, collagen/DDR1 axis is able to trigger the downregulation of cell proliferation and the activation of BIK-mediated apoptosis pathway. The aim of this review is to discuss the role of two important factors that regulate these processes. The first factor is the level of DDR1 expression. DDR1 is highly expressed in epithelial-like breast carcinoma cells, but poorly in basal-like ones. Moreover, DDR1 undergoes cleavage by MT1-MMP, which is highly expressed in basal-like breast carcinoma cells. The second factor is type I collagen remodeling since DDR1 activation depends on its fibrillar organization. Collagen remodeling is involved in the regulation of cell proliferation and apoptosis through age- and proteolysis-related modifications.