Insights into the Role of Gremlin-1, a Bone Morphogenic Protein Antagonist, in Cancer Initiation and Progression

Ex.50.T aptamer impairs tumor-stroma cross-talk in breast cancer by targeting gremlin-1

The tumor microenvironment profoundly influences tumor complexity, particularly in breast cancer, where cancer-associated fibroblasts play pivotal roles in tumor progression and therapy resistance. Extracellular vesicles are involved in mediating communication within the TME, specifically highlighting their role in promoting the transformation of normal fibroblasts into cancer-associated fibroblasts. Recently, we identified an RNA aptamer, namely ex.50.T, that binds with remarkable affinity to extracellular vesicles shed from triple-negative breast cancer cells. Here, through in vitro assays and computational analyses, we demonstrate that the binding of ex.50.T to extracellular vesicles and parental breast cancer cells is mediated by recognition of gremlin-1 (GREM1), a bone morphogenic protein antagonist implicated in breast cancer aggressiveness and metastasis. Functionally, we uncover the role of ex.50.T as an innovative therapeutic agent in the process of tumor microenvironment re-modeling, impeding GREM1 signaling, blocking triple-negative breast cancer extracellular vesicles internalization in recipient cells, and counteracting the transformation of normal fibroblasts into cancer-associated fibroblasts. Altogether, our findings highlight ex.50.T as a novel therapeutical avenue for breast cancer and potentially other GREM1-dependent malignancies, offering insights into disrupting TME dynamics and enhancing cancer treatment strategies.

A comprehensive prognostic and immunological implications of Gremlin 1 in lung adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is a prevalent form of lung cancer globally, known for its high invasiveness, metastatic potential, and notable heterogeneity, particularly in its response to immunotherapy. Gremlin 1 (GREM1) is implicated in tumor progression and poor prognosis in multiple cancers. However, GREM1's specific role in LUAD remains unclear. This study systematically examines GREM1 expression in LUAD and its association with tumor progression, immune microenvironment, and prognosis.

Methods

Gene expression data from the TCGA and GSE31210 databases were analyzed using Weighted Gene Co-expression Network Analysis (WGCNA), GO and KEGG enrichment analyses. The prognostic value of GREM1 was evaluated through survival analysis, Cox regression, and Kaplan-Meier curves. Additionally, immune microenvironment analysis was conducted to explore the relationship between GREM1 and immune cell infiltration. In vitro experiments, including Western blot and assays for cell proliferation, migration, and invasion, were performed to confirm the specific role of GREM1 in LUAD cells.

Results

GREM1 was significantly upregulated in tumor tissues and correlated with poor prognosis. Moreover, GREM1 was significantly associated with immune cell infiltration and immunotherapy response within the immune microenvironment. In vitro experiments confirmed that GREM1 overexpression significantly promoted LUAD cell proliferation, migration, and epithelial-mesenchymal transition (EMT), whereas GREM1 knockdown suppressed these functions.

Conclusions

A comprehensive analysis indicates that GREM1 is crucial in LUAD progression, with its overexpression predicting poor prognosis. GREM1 could be a potential therapeutic target for LUAD, providing insights for personalized therapy optimization.

Quantification of Gremlin 1 throughout the tumor stroma using whole slide imaging and its clinicopathological significance in gastric cancer

Gremlin 1 (GREM1) is an antagonist of bone morphogenetic protein (BMP). GREM1 is expressed in the stromal cells of various carcinomas and promotes tumor progression by suppressing BMP signaling. We designed this study to establish an evaluation strategy for GREM1 expression, focusing on the tumor stroma, and to examine its clinicopathological significance in gastric cancer (GC) progression. We employed RNA in situ hybridization (ISH) to evaluate the prognostic value of GREM1 expression in a cohort of 104 surgically resected GC cases and assessed ISH scores according to previous reports. GREM1 expression was observed in tumor stromal cells, including fibroblasts. We defined GREM1-positive cells as those expressing ISH score ≥ 3 and quantified the number of GREM1-positive cells using image analysis software. We examined the relationship between the number of GREM1-positive cells in the tumor stroma and clinicopathological features. The number of GREM1-positive cells per tumor stroma ranged from 0 to 714.7 cells/mm2 (median, 1.65 cells/mm2). We divided the 104 GC cases into GREM1-High and GREM1-Low expression groups based on the abovementioned median value. GREM1-High expression group was significantly associated with a more advanced pT grade, pN grade, lymphatic invasion, and venous invasion. Kaplan-Meier analysis showed significantly poorer survival in the GREM1-High expression group than in the GREM1-Low expression group. These results indicated that GREM1 expression in GC is localized in tumor stromal cells, and that high GREM1 expression in the tumor stroma could be a poor prognostic factor.

Transcriptomic Response of the Ovarian Follicle Complex in Post-Vitellogenic Rainbow Trout to 17α,20β-Dihdroxy-4-pregnen-3-one In Vitro

Gonadotropins and progestins are the primary regulators of follicle maturation and ovulation in fish, and they require complex communication among the oocyte and somatic cells of the follicle. The major progestin and the maturation-inducing hormone in salmonids is 17α,20β-dihdroxy-4-pregnen-3-one (17,20βP), and traditional nuclear receptors and membrane steroid receptors for the progestin have been identified within the follicle. Herein, RNA-seq was used to conduct a comprehensive survey of changes in gene expression throughout the intact follicle in response to in vitro treatment with these hormones to provide a foundation for understanding the coordination of their actions in regulating follicle maturation and preparation for ovulation. A total of 5292 differentially expressed genes were identified from our transcriptome sequencing datasets comparing four treatments: fresh tissue; untreated control; 17,20βP-treated; and salmon pituitary homogenate-treated follicles. Extensive overlap in affected genes suggests many gonadotropin actions leading to the acquisition of maturational and ovulatory competence are mediated in part by gonadotropin induction of 17,20βP synthesis. KEGG analysis identified signaling pathways, including MAPK, TGFβ, FoxO, and Wnt signaling pathways, among the most significantly enriched pathways altered by 17,20βP treatment, suggesting pervasive influences of 17,20βP on actions of other endocrine and paracrine factors in the follicle complex.

Gremlin-1 in pregnancy and postpartum: relation to the fatty liver index, markers of bone health, glucose metabolism and gestational diabetes mellitus status

INTRODUCTION

Gremlin-1 is a peptide that functions as an antagonist to bone morphogenic proteins and is overexpressed in obesity and type 2 diabetes mellitus. Gremlin-1 has not yet been investigated in pregnancy, pregnancy-related insulin resistance or gestational diabetes mellitus (GDM).

PATIENTS AND METHODS

Gremlin-1 levels were measured throughout the pregnancy of 58 women at high risk for GDM at the Medical University of Vienna. Furthermore, an oral glucose tolerance test, fasting insulin, fasting glucose, sex hormones, blood lipids, liver and renal parameters, and markers of bone development were evaluated at two points during pregnancy (< 20 weeks of gestation (GW), GW 24-28) and 12-14 weeks postpartum.

RESULTS

Gremlin-1 levels decreased from < 20 GW (mean = 9.2 pg/ml, SD = 8.4 pg/ml) to GW 24-28 (mean = 6.7 pg/ml, SD = 5.7 pg/ml, p = 0.033) and increased again postpartum, albeit not significantly (mean = 10.7 pg/ml, SD = 13.1 pg/ml, p = 0.339). During pregnancy, Gremlin-1 levels correlated negatively with osteocalcin and procollagen type I aminoterminal propeptide (P1NP), markers of bone health. Concerning glucose metabolism, Gremlin-1 levels were inversely related to the Insulinogenic Index at GW < 20. However, Gremlin-1 levels were not significantly different between women with normal glucose tolerance and GDM during pregnancy. Postpartum, Gremlin-1 was associated with the fatty liver index, osteocalcin levels, diastolic blood pressure and weight.

CONCLUSION

Gremlin-1 levels decreased significantly during pregnancy. The biomarker is not related to GDM status, but correlates negatively with the Insulinogenic Index, an index related to beta cell function. Trial Registry Number ACTRN12616000924459.

Role of gremlin-1 in the pathophysiology of the adipose tissues

Gremlin-1 is a secreted bone morphogenetic protein (BMP) antagonist playing a pivotal role in the regulation of tissue formation and embryonic development. Since its first identification in 1997, gremlin-1 has been shown to be a multifunctional factor involved in wound healing, inflammation, cancer and tissue fibrosis. Among others, the activity of gremlin-1 is mediated by its interaction with BMPs or with membrane receptors such as the vascular endothelial growth factor receptor 2 (VEGFR2) or heparan sulfate proteoglycans (HSPGs). Growing evidence has highlighted a central role of gremlin-1 in the homeostasis of the adipose tissue (AT). Of note, gremlin-1 is involved in AT dysfunction during type 2 diabetes, obesity and non-alcoholic fatty liver disease (NAFLD) metabolic disorders. In this review we discuss recent findings on gremlin-1 involvement in AT biology, with particular attention to its role in metabolic diseases, to highlight its potential as a prognostic marker and therapeutic target.

Long noncoding RNA long intergenic non-protein-coding RNA 173 contributes to nasopharyngeal carcinoma progression by regulating microRNA-765/Gremlin 1 pathway

BACKGROUND

Long intergenic non-protein-coding RNA 173 (LINC00173) executes vital functions in various cancers. Nevertheless, its role and expression in nasopharyngeal carcinoma (NPC) have yet to be investigated. Here, we investigated its effects on the malignancy characteristics of NPC and elucidated the potential molecular mechanism of LINC00173 in NPC progression.

METHODS

Quantitative real-time reverse transcription-PCR (qRT-PCR) and immunoblotting were conducted to estimate the LINC00173, microRNA-765 (miR-765), and Gremlin 1 (GREM1) expressions in NPC cells and tissues. Cell counting kit-8 (CCK8), colony formation, and wound healing experiments were done to evaluate the proliferation, growth, and migration of NPC cells, respectively. The tumorous growth of NPC cells in vivo was assessed through the xenograft tumor experiment. Furthermore, the interactions among miR-765, LINC00173, and GREM1 were investigated through bioinformatics analyses, luciferase reporter and RNA immunoprecipitation chip assays.

RESULTS

An upregulated LINC00173 expression was found in NPC cell lines and tissues. The functional experiments uncovered that its downregulation repressed NPC cell proliferation, growth, and migration. In addition, LINC00173 knockdown hampered the NPC cells' tumorous growth in vivo. These effects could partially be reversed by downregulating miR-765. GREM1 is a downstream target of miR-765. GREM1 knockdown could repress the proliferation, growth, and migration of NPC cells. Nonetheless, these anti-tumor effects could be abolished by miR-765 downregulation. Mechanistically, LINC00173 increased the expression of GREM1 by binding with miR-765.

CONCLUSIONS

LINC00173 functions as an oncogenic factor by binding with miR-765 to promote the progression of NPC via GREM1 upregulation. This study provides a novel insight into the molecular mechanisms involved in NPC progression.

Discovery of ginisortamab, a potent and novel anti-gremlin-1 antibody in clinical development for the treatment of cancer

Gremlin-1, a high-affinity antagonist of bone morphogenetic proteins (BMP)-2, -4, and -7, is implicated in tumor initiation and progression. Increased gremlin-1 expression, and therefore suppressed BMP signaling, correlates with poor prognosis in a range of cancer types. A lack of published work using therapeutic modalities has precluded the testing of the hypothesis that blocking the gremlin-1/BMP interaction will provide benefits to patients. To address this shortfall, we developed ginisortamab (UCB6114), a first-in-class clinical anti-human gremlin-1 antibody, currently in clinical development for the treatment of cancer, along with its murine analog antibody Ab7326 mouse immunoglobulin G1 (mIgG1). Surface plasmon resonance assays revealed that ginisortamab and Ab7326 mIgG1 had similar affinities for human and mouse gremlin-1, with mean equilibrium dissociation constants of 87 pM and 61 pM, respectively. The gremlin-1/Ab7326 antigen-binding fragment (Fab) crystal structure revealed a gremlin-1 dimer with a Fab molecule bound to each monomer that blocked BMP binding. In cell culture experiments, ginisortamab fully blocked the activity of recombinant human gremlin-1, and restored BMP signaling pathways in human colorectal cancer (CRC) cell lines. Furthermore, in a human CRC - fibroblast co-culture system where gremlin-1 is produced by the fibroblasts, ginisortamab restored BMP signaling in both the CRC cells and fibroblasts, demonstrating its activity in a relevant human tumor microenvironment model. The safety and efficacy of ginisortamab are currently being evaluated in a Phase 1/2 clinical trial in patients with advanced solid tumors (NCT04393298).