Elevated expression of neuropilin-2 associated with unfavorable prognosis in hepatocellular carcinoma

The Significance of Neuropilins in Gastrointestinal Cancers

Cancers represent a significant global health concern, being among the most prevalent malignancies and contributing substantially to morbidity and mortality rates. Notably, colorectal, gastric, pancreatic, and liver cancers are the most frequently diagnosed among these malignancies. The pathogenesis of gastrointestinal (GI) cancers is multifactorial, encompassing a complex interplay of genetic predispositions, environmental exposures, and lifestyle choices. Despite advances in diagnostic approaches and therapeutic strategies, existing treatment modalities, particularly in the advanced stages of these cancers, remain ineffective. Recent research efforts have increasingly focused on the identification and characterization of novel biomarkers that could enhance both the detection and treatment of gastrointestinal cancers. One particularly promising area of investigation involves neuropilins (NRPs). NRPs are involved in essential biological processes such as angiogenesis, cellular migration, and tumor cell-microenvironment interactions, all of which promote tumor progression and contribute to the development of treatment resistance. Overexpression of neuropilins has been linked to poor prognosis in patients, implying that they could be useful in diagnosis and serve as targets for molecular treatment. Recent research also suggests that inhibiting neuropilin activity may slow tumor growth and inhibit angiogenic processes, opening up new possibilities for targeted therapeutic techniques in the treatment of gastrointestinal malignancies.

Biology of childhood hepatoblastoma and the search for novel treatments

Our research laboratory has a longstanding interest in developmental disorders and embryonic tumors, and recent efforts have focused on the pathogenesis of pediatric liver tumors. This review focuses on hepatoblastoma (HB), the most common pediatric liver malignancy. Despite advances in treatment, patients with metastatic HB have a poor prognosis, and survivors often have permanent side effects attributable to chemotherapy. In an effort to improve survival and lessen long-term complications of HB, we have searched for novel molecular vulnerabilities using a combination of patient derived cell lines, metabolomics, and RNA sequencing of human samples at diagnosis and follow-up. These studies have shed light on pathogenesis and identified putative targets for future therapies in children with advanced HB.

Development and Characterization of a Novel Neuropilin-2 Antibody for Immunohistochemical Staining of Cancer and Sarcoidosis Tissue Samples

Neuropilin-2 (NRP2) is a cell surface receptor that plays key roles in lymphangiogenesis, but also in pathophysiological conditions such as cancer and inflammation. NRP2 targeting by efzofitimod, a novel immunomodulatory molecule, is currently being tested for the treatment of pulmonary sarcoidosis. To date, no anti-NRP2 antibodies are available for companion diagnostics. Here we describe the development and characterization of a novel NRP2 antibody. Using a variety of research techniques, that is, enzyme-linked immunoassay, Western blot, biolayer interferometry, and immunohistochemistry, we demonstrate that our antibody detects all major NRP2 isoforms and does not cross-react with NRP1. Using this antibody, we show high NRP2 expression in granulomas from sarcoidosis patient skin and lung biopsies. Our novel anti-NRP2 antibody could prove to be a useful clinical tool for sarcoidosis and other indications where NRP2 has been implicated. Clinical Trial Registration: clinicaltrials.gov NCT05415137.

Neuropilins as potential biomarkers in hepatocellular carcinoma: a systematic review of basic and clinical implications

Hepatocellular carcinoma (HCC) is one of the most common and deadly cancers worldwide and is characterized by complex molecular carcinogenesis. Neuropilins (NRPs) NRP1 and NRP2 are the receptors of multiple proteins involved in key signaling pathways associated with tumor progression. We aimed to systematically review all the available findings on their role in HCC. We searched the Scopus, Web of Science (WOS), PubMed, Cochrane and Embase databases for articles evaluating NRPs in preclinical or clinical HCC models. This study was registered in PROSPERO (CRD42022349774) and include 49 studies. Multiple cellular and molecular processes have been associated with one or both NRPs, indicating that they are potential diagnostic and prognostic biomarkers in HCC patients. Mainly NRP1 has been shown to promote tumor cell survival and progression by modulating several signaling pathways. NRPs mainly regulate angiogenesis, invasion and migration and have shown to induce invasion and metastasis. They also regulate the immune response and tumor microenvironment, showing a crucial interplay with the hypoxia response and microRNAs in HCC. Altogether, NRP1 and NRP2 are potential biomarkers and therapeutic targets, providing novel insight into the clinical landscape of HCC patients.

Neuropilin (NRPs) Related Pathological Conditions and Their Modulators

Neuropilin 1 (NRP1) represents one of the two homologous neuropilins (NRP, splice variants of neuropilin 2 are the other) found in all vertebrates. It forms a transmembrane glycoprotein distributed in many human body tissues as a (co)receptor for a variety of different ligands. In addition to its physiological role, it is also associated with various pathological conditions. Recently, NRP1 has been discovered as a coreceptor for the SARS-CoV-2 viral entry, along with ACE2, and has thus become one of the COVID-19 research foci. However, in addition to COVID-19, the current review also summarises its other pathological roles and its involvement in clinical diseases like cancer and neuropathic pain. We also discuss the diversity of native NRP ligands and perform a joint analysis. Last but not least, we review the therapeutic roles of NRP1 and introduce a series of NRP1 modulators, which are typical peptidomimetics or other small molecule antagonists, to provide the medicinal chemistry community with a state-of-the-art overview of neuropilin modulator design and NRP1 druggability assessment.

Role of Neuropilin-2-mediated signaling axis in cancer progression and therapy resistance

Neuropilins (NRPs) are transmembrane proteins involved in vascular and nervous system development by regulating angiogenesis and axon guidance cues. Several published reports have established their role in tumorigenesis. NRPs are detectable in tumor cells of several cancer types and participate in cancer progression. NRP2 is also expressed in endothelial and immune cells in the tumor microenvironment and promotes functions such as lymphangiogenesis and immune suppression important for cancer progression. In this review, we have taken a comprehensive approach to discussing various aspects of NRP2-signaling in cancer, including its regulation, functional significance in cancer progression, and how we could utilize our current knowledge to advance the studies and target NRP2 to develop effective cancer therapies.

TGF-β superfamily co-receptors in cancer

Transforming growth factor-β (TGF-β) superfamily signaling via their cognate receptors is frequently modified by TGF-β superfamily co-receptors. Signaling through SMAD-mediated pathways may be enhanced or depressed depending on the specific co-receptor and cell context. This dynamic effect on signaling is further modified by the release of many of the co-receptors from the membrane to generate soluble forms that are often antagonistic to the membrane-bound receptors. The co-receptors discussed here include TβRIII (betaglycan), endoglin, BAMBI, CD109, SCUBE proteins, neuropilins, Cripto-1, MuSK, and RGMs. Dysregulation of these co-receptors can lead to altered TGF-β superfamily signaling that contributes to the pathophysiology of many cancers through regulation of growth, metastatic potential, and the tumor microenvironment. Here we describe the role of several TGF-β superfamily co-receptors on TGF-β superfamily signaling and the impact on cellular and physiological functions with a particular focus on cancer, including a discussion on recent pharmacological advances and potential clinical applications targeting these co-receptors.

NR2F1-AS1 Promotes Pancreatic Ductal Adenocarcinoma Progression Through Competing Endogenous RNA Regulatory Network Constructed by Sponging miRNA-146a-5p/miRNA-877-5p

The role of NR2F1-AS1 in pancreatic ductal adenocarcinoma (PDAC) remains unknown. Therefore, we aimed to investigate the biological mechanism of NR2F1-AS1 in PDAC. The expression of NR2F1-AS1 was measured by using microarray data and real-time PCR. The effects of NR2F1-AS1 knockdown on proliferation, cell cycle progression, invasion in vitro and tumorigenesis in vivo were investigated. The mechanism of competitive endogenous RNAs was determined from bioinformatics analyses and validated by a dual-luciferase reporter gene assay. Potential target mRNAs from TargetScan 7.2 were selected for subsequent bioinformatics analysis. Key target mRNAs were further identified by screening hub genes and coexpressed protein-coding genes (CEGs) of NR2F1-AS1. NR2F1-AS1 was highly expressed in PDAC, and the overexpression of NR2F1-AS1 was associated with overall survival and disease-free survival. The knockdown of NR2F1-AS1 impaired PDAC cell proliferation, migration, invasion and tumorigenesis. NR2F1-AS1 competitively sponged miR-146a-5p and miR-877-5p, and low expression of the two miRNAs was associated with a poor prognosis. An integrative expression and survival analysis of the hub genes and CEGs demonstrated that the NR2F1-AS1–miR-146a-5p/miR-877-5p–GALNT10/ZNF532/SLC39A1/PGK1/LCO3A1/NRP2/LPCAT2/PSMA4 and CLTC ceRNA networks were linked to the prognosis of PDAC. In conclusion, NR2F1-AS1 overexpression was significantly associated with poor prognosis. NR2F1-AS1 functions as an endogenous RNA to construct a novel ceRNA network by competitively binding to miR-146a-5p/miR-877-5p, which may contribute to PDAC pathogenesis and could represent a promising diagnostic biomarker or potential novel therapeutic target in PDAC.

NRP2, a potential biomarker for oral squamous cell carcinoma

BACKGROUND

Neuropilin-2 (NRP2) is a single chain transmembrane glycoprotein that acts as a co-receptor of VEGF and is related to the pathogenesis of various tumors closely. However, the clinical significance of NRP2 in oral squamous cell carcinoma (OSCC) is unclear.

PURPOSE

The objective of this study was to investigate the role of NRP2 in the pathogenesis of OSCC and explore the associated mechanisms.

MATERIALS AND METHODS

GEPIA (gene expression profiling interactive analysis) was used to analyze the expression of NRP2 in OSCC. Immunohistochemistry and RT-qPCR were used to detect NRP2 expression in 80 OSCC samples. The clinical correlations and prognostic significance of NRP2 expression were evaluated. In addition, the biological functions of OSCC cells transfected with shNRP2 were evaluated. The expression levels of β-catenin, C-myc, cyclin D1, and MMP-2 in Wnt/β-catenin signaling pathway were assessed by RT-qPCR after inhibiting the expression of NRP2 in SCC-25 cell line.

RESULTS

Analysis of cases using GEPIA revealed that NRP2 was substantially upregulated in OSCC. NRP2 expression was also significantly higher in our OSCC samples than in the controls. Elevated expression of NRP2 was correlated with lymph node metastasis (P<0.01) and distant metastasis (P<0.05) in OSCC patients, and high NRP2 levels, lymph node metastasis, and distant metastasis were associated with poor prognosis (Kaplan-Meier analysis; P<0.05). Univariate and multivariate Cox analysis showed that lymph node metastasis, distant metastasis, and NRP2 expression were independent risk factors for overall survival (OS) and disease-free survival (DFS) in OSCC patients (P<0.05). Furthermore, the proliferation, migration, and invasion of OSCC cells were inhibited by shNRP2. Following inhibiting of NRP2 expression in the SCC-25 cell line, the expression levels of β-catenin, C-myc, cyclin D1, and MMP-2 were reduced (P<0.05).

CONCLUSION

This study shows that NRP2 functions as a tumor promoter gene in OSCC by affecting the proliferation, migration, and invasion of OSCC cells and downregulating the Wnt/β-catenin pathway. These results highlight the potential role for NRP2 as a clinical diagnostic marker.

N2E4, a Monoclonal Antibody Targeting Neuropilin-2, Inhibits Tumor Growth and Metastasis in Pancreatic Ductal Adenocarcinoma via Suppressing FAK/Erk/HIF-1α Signaling

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with extremely limited treatment; the effective targeting strategy stays an urgent unmet need. Neuropilin-2 (NRP2), a multifunctional transmembrane non-tyrosine-kinase glycoprotein, enhances various signal transduction pathways to modulate cancer progression. However, the application value of NRP2 as a therapeutic target in pancreatic cancer is still unclear. Here, we detected the elevated NRP2 was associated with the poor prognosis of pancreas carcinoma. The mouse monoclonal antibody targeting NRP2 (N2E4) that could specifically bind to PDAC cells was developed. Moreover, N2E4 inhibits PDAC proliferation, migration, and invasion in vitro, and repressed growth and metastasis in vivo. Mechanistically, the effect of N2E4 was mainly related to the blocking of interaction between NRP2 with integrinβ1 to inhibit FAK/Erk/HIF-1a/VEGF signaling. Therefore, N2E4 has the potential for targeting therapy of PDAC. This study lays a foundation for the future development of NRP2-based targeted therapy for PDAC.

Neuropilin-2 Is Associated With Increased Hepatoblastoma Cell Viability and Motility

The neuropilins NRP1 and NRP2 are multifunctional glycoproteins that have been implicated in several cancer-related processes including cell survival, migration, and invasion in various tumor types. Here, we examine the role of neuropilins in hepatoblastoma (HB), the most common pediatric liver malignancy. Using a combination of immunohistochemistry, RNA analysis and western blotting, we observed high level expression of NRP1 and NRP2 in 19 of 20 HB specimens and in a majority of human HB cell lines (HUH6 and five cell lines established from patient-derived xenografts) studied but not in normal hepatocytes. Silencing of NRP2 expression in HUH6 and HB-282 HB cells resulted in decreased cell viability, impaired cytoskeleton remodeling, and reduced cell motility, suggesting that NRP2 contributes to the malignant phenotype. We propose that neuropilins warrant further investigation as biomarkers of HB and potential therapeutic targets.

MiR-146a Regulates Migration and Invasion by Targeting NRP2 in Circulating-Tumor Cell Mimicking Suspension Cells

Cancer metastasis is the primary cause of cancer-related death and metastatic cancer has circulating-tumor cells (CTCs), which circulate in the bloodstream before invading other organs. Thus, understanding the precise role of CTCs may provide new insights into the metastasis process and reduce cancer mortality. However, the molecular characteristics of CTCs are not well understood due to a lack of number of CTCs. Therefore, suspension cells were generated from MDA-MB-468 cells to mimic CTCs, and we investigate the microRNA (miRNA)-dependent molecular networks and their role in suspension cells. Here, we present an integrated analysis of mRNA and miRNA sequencing data for suspension cell lines, through comparison with adherent cells. Among the differentially regulated miRNA–mRNAs axes, we focus on the miR-146a-Neuropilin2 (NRP2) axis, which is known to influence tumor aggressiveness. We show that miR-146a directly regulates NRP2 expression and inhibits Semaphorin3C (SEMA3C) signaling. Functional studies reveal that miR-146a represses SEMA3C-induced invasion and proliferation by targeting NRP2. Finally, high-NRP2 is shown to be associated with poor outcomes in breast cancer patients. This study identifies the key role of the miR-146a–NRP2 signaling axis that is critical for the regulation of migration and invasion in CTC-mimicking cells.

Clinical significance of neuropilin-2 expression in laryngeal squamous cell carcinoma

PURPOSE

The purpose of the study is to evaluate the expression of NRP-2 and explore its role in Laryngeal squamous cell carcinoma (LSCC).

MATERIALS AND METHODS

NRP-2 expression in 70 primary LSCC tissue specimens were analyzed by immunohistochemistry and correlated with clinicopathological parameters and patients´ survival rate. Additionally, 9 paired LSCC tissues were evaluated for NRP-2 expression by Western blotting.

RESULTS

The Western blotting indicated that NRP-2 expression levels in LSCC were significantly higher than those in the paraneoplastic tissues (P < 0.05). Immunohistochemistry staining revealed that NRP-2 was detected in all primary tumor samples, moreover, high expression of NRP-2 was significantly correlated with TNM stage (P < 0.05), clinical stage (P < 0.05), histological classification (P < 0.05), lymph node metastasis (P < 0.05) and recurrence (P = 0.001). Survival curves determined by the Kaplan-Meier method showed that high expression of NRP-2 can reduce overall survival (both group P < 0.05). Then we combined the NRP-2 expression and lymph node status, and Kaplan-Meier survival showed patients with high expression of NRP-2 or lymph node metastasis (+) had both shorter disease-free and overall survival than others (both P < 0.05). Multivariate Cox proportional hazards model analysis confirmed that histological grade (P = 0.045), lymph node metastasis (P = 0.020) and high expression of NRP-2 (P = 0.033) were statistically significant, independent predictor of prognosis.

CONCLUSIONS

NRP-2 may contribute to LSCC progression and represents as a novel prognostic indicator as well as a potential therapeutic target for LSCC.

Neuropilin-2 contributes to tumor progression in preclinical models of small intestinal neuroendocrine tumors

The identification of novel regulators of tumor progression is a key challenge to gain knowledge on the biology of small intestinal neuroendocrine tumors (SI-NETs). We recently identified the loss of the axon guidance protein semaphorin 3F as a protumoral event in SI-NETs. Interestingly the expression of its receptor neuropilin-2 (NRP-2) was still maintained. This study aimed at deciphering the potential role of NRP-2 as a contributor to SI-NET progression. The role of NRP-2 in SI-NET progression was addressed using an approach integrating human tissue and serum samples, cell lines and in vivo models. Data obtained from human SI-NET tissues showed that membranous NRP-2 expression is present in a majority of tumors, and is correlated with invasion, metastatic abilities, and neovascularization. In addition, NRP-2 soluble isoform was found elevated in serum samples from metastatic patients. In preclinical mouse models of NET progression, NRP-2 silencing led to a sustained antitumor effect, partly driven by the downregulation of VEGFR2. In contrast, its ectopic expression conferred a gain of aggressiveness, driven by the activation of various oncogenic signaling pathways. Lastly, NRP-2 inhibition led to a decrease of tumor cell viability, and sensitized to therapeutic agents. Overall, our results point out NRP-2 as a potential therapeutic target for SI-NETs, and will foster the development of innovative strategies targeting this receptor. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Roles for VEGF-C/NRP-2 axis in regulating renal tubular epithelial cell survival and autophagy during serum deprivation

Vascular endothelial growth factor C (VEGF-C) is an angiogenic and lymphangiogenic growth factor. Recent research has revealed the role for VEGF-C in regulating autophagy by interacting with a nontyrosine kinase receptor, neuropilin-2 (NRP-2). However, whether VEGF-C participates in regulating cell survival and autophagy in renal proximal tubular cells is unknown. To address this question, we employed a cell modal of serum deprivation to verify the role of VEGF-C and its receptor NRP-2 in regulating cell survival and autophagy in NRK52E cell lines. The results show that VEGF-C rescued the loss of cell viability induced by serum deprivation in a concentration-dependent manner. Furthermore, endogenous VEGF-C was knocked down in NRK52E cells by using specific small-interfering RNAs (siRNA), cells were more sensitive to serum deprivation-induced cell death. A similar increase in cell death rate was observed following NRP-2 depletion in serum-starved NRK52E cells. Autophagy activity in serum-starved NRK52E cells was confirmed by western blot analysis of microtubule-associated protein-1 chain 3 (LC3), immunofluorescence staining of endogenous LC3, and the formation of autophagosomes by electron microscopy. VEGF-C or NRP-2 depletion further increased LC3 expression induced by serum deprivation, suggesting that VEGF-C and NRP-2 were involved in controlling autophagy in NRK52E cells. We further performed autophagic flux experiments to identify that VEGF-C promotes the activation of autophagy in serum-starved NRK52E cells. Together, these results suggest for the first time that VEGF-C/NRP-2 axis promotes survival and autophagy in NRK52E cells under serum deprivation condition. SIGNIFICANCE OF THE STUDY: More researchers had focused on the regulation of autophagy in kidney disease. The effect of VEGF-C on cell death and autophagy in renal epithelial cells has not been examined. We first identified the VEGF-C as a regulator of cell survival and autophagy in NRK52E cell lines. And VEGF-C/NRP-2 may mediate autophagy by regulating the phosphorylation of 4EBP1 and P70S6K. VEGF-C treatment may be identified as a therapeutic target in renal injury repair due to its capacity to promote tubular cell survival in the future.

Cyclosporin A induces autophagy in cardiac fibroblasts through the NRP-2/WDFY-1 axis

Cyclosporin A (CsA) is an effective immunosuppressive agent, but its myocardial toxicity limits its widespread and long-term clinical application. In this study, CsA treatment led to damages in myocardial fiber structure, an increase in myocardial fibrosis, and changes in heart size and shape; moreover, the degree of damage was exacerbated with prolonged drug application and increases in dose. However, the mechanism is not clear; therefore, the purpose of this study was to reveal the mechanism of CsA-induced myocardial fibrosis and identify a new target for the prevention and treatment of CsA-induced myocardial injury. Cardiac fibroblasts were treated with CsA (5, 10, or 20 μg/mL) for 24 h. Autophagy was observed by electron microscopy and immunofluorescence. The expression of NRP-2/WDFY-1, autophagy-related proteins (Beclin1 and LC3B), fibrosis-related proteins (MMP2/9), and fibroblast phenotype conversion factor (α-SMA) was evaluated by Western blot. The expression of collagen I was determined by ELISA. Then, we used the gene interference technique to alter WDFY-1 expression with or without CsA or 3-MA treatment for 24 h, and the effects on autophagy and the expression of autophagy-related proteins, fibrosis-associated proteins, IFN-α, TNF-α, and IL-6 were determined. The results showed the following: (1) CsA induced fibrosis-related protein (MMP2/9), fibroblast phenotype conversion factor (α-SMA), and collagen I up-regulation in a dose-dependent manner. (2) CsA induced the formation of autophagosomes and up-regulated the expression of Beclin1, LC3B, and the ERK/MAPK pathway in cardiac fibroblasts. (3) CsA induced NRP-2 down-regulation and WDFY-1 up-regulation. (4) Depletion of WDFY-1 inhibited CsA-induced autophagy, TNF-α and IFN-α up-regulation, and fibrosis. (5) The autophagy inhibitor 3-MA inhibited CsA-induced TNF-α and IFN-α up-regulation and fibrosis. Overall, cyclosporin A induces autophagy in cardiac fibroblasts through the NRP-2/WDFY-1 axis, which promotes the progression of myocardial fibrosis.