Neuropilin-2 Is upregulated in lung cancer cells during TGF-β1-induced epithelial-mesenchymal transition

Orchestrating Resilience: How Neuropilin-2 and Macrophages Contribute to Cardiothoracic Disease

Immunity has evolved to balance the destructive nature of inflammation with wound healing to overcome trauma, infection, environmental insults, and rogue malignant cells. The inflammatory response is marked by overlapping phases of initiation, resolution, and post-resolution remodeling. However, the disruption of these events can lead to prolonged tissue damage and organ dysfunction, resulting long-term disease states. Macrophages are the archetypic phagocytes present within all tissues and are important contributors to these processes. Pleiotropic and highly plastic in their responses, macrophages support tissue homeostasis, repair, and regeneration, all while balancing immunologic self-tolerance with the clearance of noxious stimuli, pathogens, and malignant threats. Neuropilin-2 (Nrp2), a promiscuous co-receptor for growth factors, semaphorins, and integrins, has increasingly been recognized for its unique role in tissue homeostasis and immune regulation. Notably, recent studies have begun to elucidate the role of Nrp2 in both non-hematopoietic cells and macrophages with cardiothoracic disease. Herein, we describe the unique role of Nrp2 in diseases of the heart and lung, with an emphasis on Nrp2 in macrophages, and explore the potential to target Nrp2 as a therapeutic intervention.

Deficiency of inflammation-sensing protein neuropilin-2 in myeloid-derived macrophages exacerbates colitis via NF-κB activation

Neuropilin-2 (NRP2) is a multifunctional protein engaged in the regulation of angiogenesis, lymphangiogenesis, axon guidance, and tumor metastasis, but its function in colitis remains unclear. Here, we found that NRP2 was an inflammation-sensing protein rapidly and dramatically induced in myeloid cells, especially in macrophages, under inflammatory contexts. NRP2 deficiency in myeloid cells exacerbated dextran sulfate sodium salt-induced experimental colitis by promoting polarization of M1 macrophages and colon injury. Mechanistically, NRP2 could be induced via NF-κB activation by TNF-α in macrophages, but exerted an inhibitory effect on NF-κB signaling, forming a negative feedback loop with NF-κB to sense and alleviate inflammation. Deletion of NRP2 in macrophages broke this negative feedback circuit, leading to NF-κB overactivation, inflammatory exacerbation, and more severe colitis. Collectively, these findings reveal inflammation restriction as a role for NRP2 in macrophages under inflammation contexts and suggest that NRP2 in macrophages may relieve inflammation in inflammatory bowel disease. © 2023 The Pathological Society of Great Britain and Ireland.

Inhibition of VEGF binding to neuropilin-2 enhances chemosensitivity and inhibits metastasis in triple-negative breast cancer

Although blocking the binding of vascular endothelial growth factor (VEGF) to neuropilin-2 (NRP2) on tumor cells is a potential strategy to treat aggressive carcinomas, a lack of effective reagents that can be used clinically has hampered this potential therapy. Here, we describe the generation of a fully humanized, high-affinity monoclonal antibody (aNRP2-10) that specifically inhibits the binding of VEGF to NRP2, conferring antitumor activity without causing toxicity. Using triple-negative breast cancer as a model, we demonstrated that aNRP2-10 could be used to isolate cancer stem cells (CSCs) from heterogeneous tumor populations and inhibit CSC function and epithelial-to-mesenchymal transition. aNRP2-10 sensitized cell lines, organoids, and xenografts to chemotherapy and inhibited metastasis by promoting the differentiation of CSCs to a state that is more responsive to chemotherapy and less prone to metastasis. These data provide justification for the initiation of clinical trials designed to improve the response of patients with aggressive tumors to chemotherapy using this monoclonal antibody.

Neogenin suppresses tumor progression and metastasis via inhibiting Merlin/YAP signaling

From in situ growth to invasive dissemination is the most lethal attribute of various tumor types. This transition is majorly mediated by the dynamic interplay between two cancer hallmarks, EMT and cell cycle. In this study, we applied nonlinear association analysis in 33 cancer types and found that most signaling receptors simultaneously associating with EMT and cell cycle are potential tumor suppressors. Here we find that a top co-associated receptor, Neogenin (NEO1), inhibits colorectal cancer (CRC) and Glioma in situ growth and metastasis by forming a complex with Merlin (NF2), and subsequent simultaneous promoting the phosphorylation of YAP. Furthermore, Neogenin protein level is associated with good prognosis and correlates with Merlin status in CRC and Glioma. Collectively, our results define Neogenin as a tumor suppressor in CRC and Glioma that acts by restricting oncogenic signaling by the Merlin-YAP pathway, and suggest Neogenin as a candidate therapeutic agent for CRC and Glioma.

Advances in SEMA3F regulation of clinically high-incidence cancers

Cancer has become a leading cause of morbidity and mortality in recent years. Its high prevalence has had a severe impact on society. Researchers have achieved fruitful results in the causative factors, pathogenesis, treatment strategies, and cancer prevention. Semaphorin 3F (SEMA3F), a member of the signaling family, was initially reported in the literature to inhibit the growth, invasion, and metastasis of cancer cells in lung cancer. Later studies showed it has cancer-inhibiting effects in malignant tumors such as breast, colorectal, ovarian, oral squamous cell carcinoma, melanoma, and head and neck squamous carcinoma. In contrast, recent studies have reported that SEMA3F is expressed more in hepatocellular carcinoma than in normal tissue and promotes metastasis of hepatocellular carcinoma. We chose lung, breast, colorectal, and hepatocellular carcinomas with high clinical prevalence to review the roles and molecular mechanisms of SEMA3F in these four carcinomas. We concluded with an outlook on clinical interventions for patients targeting SEMA3F.

Immune-related gene signature associates with immune landscape and predicts prognosis accurately in patients with Wilms tumour

Wilms tumour (WT) is the most common kidney malignancy in children. Chemoresistance is the leading cause of tumour recurrence and poses a substantial therapeutic challenge. Increasing evidence has underscored the role of the tumour immune microenvironment (TIM) in cancers and the potential for immunotherapy to improve prognosis. There remain no reliable molecular markers for reflecting the immune landscape and predicting patient survival in WT. Here, we examine differences in gene expression by high-throughput RNA sequencing, focused on differentially expressed immune-related genes (IRGs) based on the ImmPort database. Via univariate Cox regression analysis and Lasso-penalized Cox regression analysis, IRGs were screened out to establish an immune signature. Kaplan-Meier curves, time-related ROC analysis, univariate and multivariate Cox regression studies, and nomograms were used to evaluate the accuracy and prognostic significance of this signature. Furthermore, we found that the immune signature could reflect the immune status and the immune cell infiltration character played in the tumour microenvironment (TME) and showed significant association with immune checkpoint molecules, suggesting that the poor outcome may be partially explained by its immunosuppressive TME. Remarkably, TIDE, a computational method to model tumour immune evasion mechanisms, showed that this signature holds great potential for predicting immunotherapy responses in the TARGET-wt cohort. To decipher the underlying mechanism, GSEA was applied to explore enriched pathways and biological processes associated with immunophenotyping and Connectivity map (CMap) along with DeSigN analysis for drug exploration. Finally, four candidate immune genes were selected, and their expression levels in WT cell lines were monitored via qRT-PCR. Meanwhile, we validated the function of a critical gene, NRP2. Taken together, we established a novel immune signature that may serve as an effective prognostic signature and predictive biomarker for immunotherapy response in WT patients. This study may give light on therapeutic strategies for WT patients from an immunological viewpoint.

A Circulating Risk Score, Based on Combined Expression of Exo-miR-130a-3p and Fibrinopeptide A, as Predictive Biomarker of Relapse in Resectable Non-Small Cell Lung Cancer Patients

Simple Summary

To date, the five-year survival rate of early stages of non-small cell lung cancer (NSCLC) is still disappointing and reliable prognostic factors are mandatory. Here, we performed in-depth high-throughput analyses of plasma circulating markers, including exosomal microRNAs and peptidome to identify a prognostic score. The miRnome profile selected the Exo-miR-130a-3p as the most overexpressed in relapsed patients. Peptidome analysis identified four progressively more degraded forms of fibrinopeptide A (FpA), which were depleted in relapse patients. Notably, a stepwise algorithm selected Exo-miR-130a-3p and the greatest FpA (2–16) to build a prognostic score, where high-risk patients had 18 months of median disease-free survival. Overexpression of miR-130a-3p cells led to a deregulation of pathways such as angiogenesis as well as the coagulation and metalloprotease, which might be linked to FpA reduction. The risk score integrating circulating markers may help clinicians predict early-stage NSCLC patients who are more likely to relapse after surgery.

Abstract

To date, the 5-year overall survival rate of 60% for early-stage non-small cell lung cancer (NSCLC) is still unsatisfactory. Therefore, reliable prognostic factors are needed. Growing evidence shows that cancer progression may depend on an interconnection between cancer cells and the surrounding tumor microenvironment; hence, circulating molecules may represent promising markers of cancer recurrence. In order to identify a prognostic score, we performed in-depth high-throughput analyses of plasma circulating markers, including exosomal microRNAs (Exo-miR) and peptides, in 67 radically resected NSCLCs. The miRnome profile selected the Exo-miR-130a-3p as the most overexpressed in relapsed patients. Peptidome analysis identified four progressively more degraded forms of fibrinopeptide A (FpA), which were depleted in progressing patients. Notably, stepwise Cox regression analysis selected Exo-miR-130a-3p and the greatest FpA (2-16) to build a score predictive of recurrence, where high-risk patients had 18 months of median disease-free survival. Moreover, in vitro transfections showed that higher levels of miR-130a-3p lead to a deregulation of pathways involved in metastasis and angiogenesis, including the coagulation process and metalloprotease increase which might be linked to FpA reduction. In conclusion, by integrating circulating markers, the identified risk score may help clinicians predict early-stage NSCLC patients who are more likely to relapse after primary surgery.

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.

Isoforms of Neuropilin-2 Denote Unique Tumor-Associated Macrophages in Breast Cancer

Tumor-associated macrophages (TAMs) exert profound influence over breast cancer progression, promoting immunosuppression, angiogenesis, and metastasis. Neuropilin-2 (NRP2), consisting of the NRP2a and NRP2b isoforms, is a co-receptor for heparin-binding growth factors including VEGF-C and Class 3 Semaphorins. Selective upregulation in response to environmental stimuli and independent signaling pathways endow the NRP2 isoforms with unique functionality, with NRP2b promoting increased Akt signaling via receptor tyrosine kinases including VEGFRs, MET, and PDGFR. Although NRP2 has been shown to regulate macrophage/TAM biology, the role of the individual NRP2a/NRP2b isoforms in TAMs has yet to be evaluated. Using transcriptional profiling and spectral flow cytometry, we show that NRP2 isoform expression was significantly higher in TAMs from murine mammary tumors. NRP2a/NRP2b levels in human breast cancer metastasis were dependent upon the anatomic location of the tumor and significantly correlated with TAM infiltration in both primary and metastatic breast cancers. We define distinct phenotypes of NRP2 isoform-expressing TAMs in mouse models of breast cancer and within malignant pleural effusions from breast cancer patients which were exclusive of neuropilin-1 expression. Genetic depletion of either NRP2 isoform in macrophages resulted in a dramatic reduction of LPS-induced IL-10 production, defects in phagosomal processing of apoptotic breast cancer cells, and increase in cancer cell migration following co-culture. By contrast, depletion of NRP2b, but not NRP2a, inhibited production of IL-6. These results suggest that NRP2 isoforms regulate both shared and unique functionality in macrophages and are associated with distinct TAM subsets in breast cancer.

Histone Methyltransferase DOT1L as a Promising Epigenetic Target for Treatment of Solid Tumors

The histone lysine methyltransferase DOT1L (DOT1-like histone lysine methyltransferase) is responsible for the epigenetic regulation of gene expression through specific methylation of lysine79 residue of histone H3 (H3K79) in actively transcribed genes. Its normal activity is crucial for embryonic development and adult tissues functions, whereas its aberrant functioning is known to contribute to leukemogenesis. DOT1L is the only lysine methyltransferase that does not contain a SET domain, which is a feature that allowed the development of selective DOT1L inhibitors that are currently investigated in Phase I clinical trials for cancer treatment. Recently, abnormal expression of this enzyme has been associated with poor survival and increased aggressiveness of several solid tumors. In this review evidences of aberrant DOT1L expression and activity in breast, ovarian, prostate, colon, and other solid tumors, and its relationships with biological and clinical behavior of the disease and response to therapies, are summarized. Current knowledge of the structural basis of DOT1L ability to regulate cell proliferation, invasion, plasticity and stemness, cell cycle progression, cell-to-cell signaling, epithelial-to-mesenchymal transition, and chemoresistance, through cooperation with several molecular partners including noncoding RNAs, is also reviewed. Finally, available options for the treatment of therapeutically challenging solid tumors by targeting DOT1L are discussed.

Bone Marrow Mesenchymal Stem Cells (BMSCs) Enhance Endometrial Stromal Cell Migration and Epithelial-Mesenchymal Transition in Adenomyosis Through Upregulation of Neuropilin 1

Hormone support (estrogen and progesterone) is a key factor in decidualization and embryo implantation. Elevated levels of estrogen lead to luteal phase defects through Neuropilin 1, a membranecytoskeleton junction protein. This study aimed to explore the effect of BMSCs on endometrial stromal cells (ESCs) in adenomyosis. ESCs obtained from patients with adenomyosis were cocultured with BMSCs in the absence of presence of Neuropilin 1 inhibitor followed by analysis of expression of decidualization-related genes by RT-qPCR and western blot, cell viability by MTT assay, cell invasion and migration by Transwell assay, oxidative stress factors by ROS kit. Treatment with Neuropilin 1 inhibitor significantly decreased ESC proliferation and invasion, blocked epithelialmesenchymal transition (EMT) process, and restrained decidualization with a downregulation of decidualization-related genes. Furthermore, inhibition of Neuropilin 1 exerted effects through estrogen regulation. However, co-culture with BMSCs restored ESC activity by promoting Neuropilin expression and enhanced intrauterine ESC decidualization. In conclusion, Neuropilin 1 inhibitor restrains decidualization through estrogen regulation which can be abrogated by estrogen receptor antagonists. BMSCs restore the damaged ESC decidualization through increasing Neuropilin 1 expression, which provides new insights into the adverse effect of Neuropilin 1 on human ESCs, suggesting that BMSC is a potential therapeutic drug candidate for adenomyosis.

Re-Expression of Poly/Oligo-Sialylated Adhesion Molecules on the Surface of Tumor Cells Disrupts Their Interaction with Immune-Effector Cells and Contributes to Pathophysiological Immune Escape

Glycans linked to surface proteins are the most complex biological macromolecules that play an active role in various cellular mechanisms. This diversity is the basis of cell-cell interaction and communication, cell growth, cell migration, as well as co-stimulatory or inhibitory signaling. Our review describes the importance of neuraminic acid and its derivatives as recognition elements, which are located at the outermost positions of carbohydrate chains linked to specific glycoproteins or glycolipids. Tumor cells, especially from solid tumors, mask themselves by re-expression of hypersialylated neural cell adhesion molecule (NCAM), neuropilin-2 (NRP-2), or synaptic cell adhesion molecule 1 (SynCAM 1) in order to protect themselves against the cytotoxic attack of the also highly sialylated immune effector cells. More particularly, we focus on α-2,8-linked polysialic acid chains, which characterize carrier glycoproteins such as NCAM, NRP-2, or SynCam-1. This characteristic property correlates with an aggressive clinical phenotype and endows them with multiple roles in biological processes that underlie all steps of cancer progression, including regulation of cell-cell and/or cell-extracellular matrix interactions, as well as increased proliferation, migration, reduced apoptosis rate of tumor cells, angiogenesis, and metastasis. Specifically, re-expression of poly/oligo-sialylated adhesion molecules on the surface of tumor cells disrupts their interaction with immune-effector cells and contributes to pathophysiological immune escape. Further, sialylated glycoproteins induce immunoregulatory cytokines and growth factors through interactions with sialic acid-binding immunoglobulin-like lectins. We describe the processes, which modulate the interaction between sialylated carrier glycoproteins and their ligands, and illustrate that sialic acids could be targets of novel therapeutic strategies for treatment of cancer and immune diseases.

Lymphatic metastasis-related TBL1XR1 enhances stemness and metastasis in gastric cancer stem-like cells by activating ERK1/2-SOX2 signaling

The poor prognosis of gastric cancer (GC) results largely from metastasis and chemotherapy resistance. Toward novel therapeutic strategies that target or evade these phenomena, we evaluated the function of the transcriptional regulator transducin (β)-like 1 X-linked receptor 1 (TBL1XR1) in GC cells, including stem-like cells. In this study, the correlation of expression of TBL1XR1 and clinical features and GC patients' outcomes was evaluated. Knockdown or exogenous expression of TBL1XR1 was combined with in vitro (2D and 3D cultures) and in vivo (mouse lung and lymphatic metastasis models) assays to evaluate the function of TBL1XR1. TBL1XR1's downstream signaling was delineated by phospho-kinase array and knockdown of candidate mediators. Analysis of clinical data showed that TBL1XR1 overexpression was correlated with worse prognosis. Functional assays showed that TBL1XR1 promoted stemness, epithelial-mesenchymal transition (EMT), and lung and lymphatic metastasis in GC cells. TBL1XR1 activated ERK1/2-Sox2 signaling and was dependent on signaling via PI3K/AKT, in GC stem-like cells distinguished by CD44 expression. Moreover, inhibition of these signaling proteins reversed chemoresistance in in vitro and in vivo models. Taken together, our results indicate that TBL1XR1 promotes stemness and metastasis in GC, making it a potential prognostic indicator. The PI3K/AKT-TBL1XR1-ERK1/2-Sox2 axis may represent a target for the treatment of GC.

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.

Neuropilin-2 promotes growth and progression of papillary thyroid cancer cells

OBJECTIVE

Neuropilin-2 (NRP2) is a coreceptor of vascular endothelial growth factor-C/D (VEGF-C/D) and plays the important role in the development of lymphatic endothelial cells, as well as neuronal development. NRP2 is known to affect aggressiveness by increasing expression in various human cancers, but the role of NRP2 in thyroid cancer is not fully understood. The purpose of this study was to investigate the NRP2 expression and its role in regulating the tumor aggressiveness in the papillary thyroid carcinoma (PTC).

METHODS

The NRP2 expression and its clinicopathologic correlation to PTC was determined using the data from the 262 PTC patients at a tertiary referral medical center and The Cancer Genome Atlas (TCGA) database. The potential role of NRP2 in modulating tumor growth, invasion, and metastasis in PTC was examined by using small interfering RNA (siRNA)-mediated knockdown of NRP2.

RESULTS

High expression of NRP2 was significantly associated with capsular invasion, lymphovascular invasion, lymph node metastasis, 5 or more metastatic lymph nodes, and recurrence in PTC patients. In TCGA data, the higher NRP2 expression group was significantly associated with extrathyroid extension, lymph node metastasis, and BRAF^V600E mutation. The siRNA mediated knockdown of NRP2 in the PTC cells reduced the cell proliferation, migration and invasion. We also have confirmed that NRP2 knockdown suppressed epithelial-mesenchymal transition (EMT) by regulating AKT and ERK phosphorylation signaling pathways.

CONCLUSION

Our results suggest that NRP2 regulates tumor progression in PTC and may act as a predictive factor for aggressiveness of PTC.

Neuropilin: Handyman and Power Broker in the Tumor Microenvironment

Neuropilin-1 and neuropilin-2 form a small family of transmembrane receptors, which, due to the lack of a cytosolic protein kinase domain, act primarily as co-receptors for various ligands. Performing at the molecular level both the executive and organizing functions of a handyman as well as of a power broker, they are instrumental in controlling the signaling of various receptor tyrosine kinases, integrins, and other molecules involved in the regulation of physiological and pathological angiogenic processes. In this setting, the various neuropilin ligands and interaction partners on various cells of the tumor microenvironment, such as cancer cells, endothelial cells, cancer-associated fibroblasts, and immune cells, are surveyed. The suitability of various neuropilin-targeting substances and the intervention in neuropilin-mediated interactions is considered as a possible building block of tumor therapy.

Linking NRP2 With EMT and Chemoradioresistance in Bladder Cancer

Neuropilin-2 (NRP2) is a prognostic indicator for reduced survival in bladder cancer (BCa) patients. Together with its major ligand, vascular endothelial growth factor (VEGF)-C, NRP2 expression is a predictive factor for treatment outcome in response to radiochemotherapy in BCa patients who underwent transurethral resection. Therefore, we investigated the benefit of combining cisplatin-based chemotherapy with irradiation treatment in the BCa cell line RT112 exhibiting or lacking endogenous NRP2 expression in order to evaluate NRP2 as potential therapeutic target. We have identified a high correlation of NRP2 and the glioma-associated oncogene family zinc finger 2 (GLI2) transcripts in the cancer genome atlas (TCGA) cohort of BCa patients and a panel of 15 human BCa cell lines. Furthermore, we used in vitro BCa models to show the transforming growth factor-beta 1 (TGFβ1)-dependent regulation of NRP2 and GLI2 expression levels. Since NRP2 was shown to bind TGFβ1, associate with TGFβ receptors, and enhance TGFβ1 signaling, we evaluated downstream signaling pathways using an epithelial-to-mesenchymal transition (EMT)-assay in combination with a PCR profiling array containing 84 genes related to EMT. Subsequent target validation in NRP2 knockout and knockdown models revealed secreted phosphoprotein 1 (SPP1/OPN/Osteopontin) as a downstream target positively regulated by NRP2.

CUB domain-containing protein 1 (CDCP1) binds transforming growth factor beta family members and increase TGF-β1 signaling pathway

CUB domains are most exclusively found in secreted proteins and in a few transmembrane proteins. These domains are approximately 110 amino acids long and have four conserved cysteines that form a β-sandwich fold. CUB domains proteins are involved in a wide range of biological functions. We have shown that CUB domains from Tolloid/BMP1 can bind BMP4 and block BMP signaling in the developing frog embryo. CUB domain-containing protein 1 (CDCP1) is one of the few transmembrane glycoprotein that contains three extracellular CUB domains and regulates anchorage-independent growth and cancer cell migration through activation of Src kinases. In the extracellular space, only a few proteins were found to interact with CDCP1 and at the moment no ligand was found. We demonstrate by using real time protein interaction on BIAcore chip that CDCP1 CUB domains bind directly to TGF-β1 and BMP4. CDCP1 enhances TGF-β1 signaling reporter activity and phosphorylated Smad2 levels but does not modulate BMP signaling pathway. CDCP1 actions on TGF-β/Smad2 signaling are dependent on Smad2 and TGFRI and do not require Src or PKCδ binding. Our findings uncover a new co-receptor for TGF-β1 and bring up new questions on whether CDCP1 cooperates with TGF-β1 to promote cancer progression.

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.

Expression of NRP-1 and NRP-2 in Endometrial Cancer

Background: Neuropilins (NRPs) participate in many processes related to cancer development such as angiogenesis, lymphangiogenesis and metastasis. Although endometrial cancer is one of the most common gynecological cancers, it has not been studied in terms of NRPs expression.

Objective: The aim of this study was to investigate the potential utility of NRPs as important factors in the diagnosis and treatment of endometrial cancer.

Methods: Our study consisted of 45 women diagnosed with endometrial cancer at the following degrees of histological differentiation: G1, 17; G2, 15; G3, 13 cases. The control group included 15 women without neoplastic changes. The immunohistochemical reactions were evaluated using light microscopy.

Results: We did not detect the expression of NRP-1 and NRP-2 in the control group. NRP-1 expression was found exclusively in cancer cells. It was higher in G2 and G3 and reached about 190% of G1. NRP-2 expression was observed in the endothelium and was similar across all three cancer grades. In cancer cells, NRP-2 expression increased with the degree of histological differentiation.

Conclusion: NRP1 and NRP2 are candidates for complementary diagnostic molecular markers and promising new targets for molecular, personalized anticancer therapies.

Semaphorins as Regulators of Phenotypic Plasticity and Functional Reprogramming of Cancer Cells

Semaphorins, initially found as neuronal guidance cues in embryo development, are now appreciated as major regulators of tissue morphogenesis and homeostasis, as well as of cancer progression. In fact, semaphorin signals have a profound impact on cell morphology, which has been commonly associated with the ability to regulate monomeric GTPases, cell-substrate adhesion, and cytoskeletal dynamics. Recently, however, several reports have indicated a novel and additional function of diverse semaphorins in the regulation of gene expression and cell phenotype plasticity. In this review article, we discuss these novel findings, focusing on the role of semaphorin signals in the regulation of bi-directional epithelial-mesenchymal transitions, stem cell properties, and drug resistance, which greatly contribute to the pathogenesis of cancer.

Neuropilins in the Context of Tumor Vasculature

Neuropilin-1 and Neuropilin-2 form a small family of plasma membrane spanning receptors originally identified by the binding of semaphorin and vascular endothelial growth factor. Having no cytosolic protein kinase domain, they function predominantly as co-receptors of other receptors for various ligands. As such, they critically modulate the signaling of various receptor tyrosine kinases, integrins, and other molecules involved in the regulation of physiological and pathological angiogenic processes. This review highlights the diverse neuropilin ligands and interacting partners on endothelial cells, which are relevant in the context of the tumor vasculature and the tumor microenvironment. In addition to tumor cells, the latter contains cancer-associated fibroblasts, immune cells, and endothelial cells. Based on the prevalent neuropilin-mediated interactions, the suitability of various neuropilin-targeted substances for influencing tumor angiogenesis as a possible building block of a tumor therapy is discussed.

Low Expression of miR-466f-3p Sustains Epithelial to Mesenchymal Transition in Sonic Hedgehog Medulloblastoma Stem Cells Through Vegfa-Nrp2 Signaling Pathway

High-throughput analysis has improved the knowledge of medulloblastoma (MB), the leading cause of cancer related death in children, allowing a better comprehension of the key molecular pathways in MB pathogenesis. However, despite these advances, 30% of patients still die from the disease and survivors face severe long-term side effects. Cancer stem cells (CSCs) represent a subset of cells that not only drive tumorigenesis, but are also one of the main determinants of chemoresistance. Epithelial mesenchymal transition (EMT) is a hallmark of cancer and up to now few data is available in MB. To give insight into the role of the EMT process in maintaining the mesenchymal phenotype of CSCs, we analyzed the expression of EMT related transcripts and microRNAs in these cells. We firstly isolated CSCs from Sonic Hedgehog (SHH) MB derived from Ptch1 heterozygous mice and compared their expression level of EMT-related transcripts and microRNAs with cerebellar NSCs. We identified two molecules linked to SHH and EMT, Vegfa and its receptor Nrp2, over-expressed in SHH MB CSCs. Inhibition of Vegfa showed impairment of cell proliferation and self-renewal ability of CSCs concurrent with an increase of the expression of the EMT gene, E-cadherin, and a decrease of the EMT marker, Vimentin. Moreover, among deregulated microRNAs, we identified miR-466f-3p, a validated inhibitor of both Vegfa and Nrp2. These results allowed us to describe a new EMT molecular network, involving the down-regulation of miR-466f-3p together with the concordant up-regulation of Vegfa and Nrp2, that sustains the mesenchymal phenotype of SHH MB CSCs.

Elevated TRIM23 expression predicts poor prognosis in Chinese gastric cancer

The gene TRIM23 (tripartite motif containing 23) is a member of the tripartite motif (TRIM) family whose expression putatively participates in many pathophysiological processes. Nonetheless, the role of TRIM23 in gastric cancer (GC) remains uncertain. Our study evaluated the expression of TRIM23 in GC tissues and cell lines, and investigated an association between TRIM23 and survival. In the present study, our results demonstrated that TRIM23 mRNA and protein were frequently over-expressed in GC cell lines and GC tissues. High level of TRIM23 protein correlated with tumor size, tumor-node-metastasis (TNM) stage, depth of invasion, lymph node metastasis (LNM), tumor differentiation, and nerve invasion. Compared with the low TRIM23 protein group, the high TRIM23 protein group was significantly associated with worse prognosis of GC patients. Consistently, the KM-plot database suggested that high TRIM23 mRNA expression was also linked to a poor prognosis in GC patients both in positive and negative subgroups of human epidermal growth factor receptor 2 (HER2). But in the HER2 positive subgroup, the advantages of the low TRIM23 expression on overall survival were much more statistically significant. The univariate analysis indicated that TRIM23 expression correlated with overall survival. The multivariate analysis showed that independent factors of prognosis in GC were lymph node metastasis, vascular invasion, and depth of invasion. In summary, TRIM23 may be associated with progression of GC, and may be considered a therapeutic target for GC patients.

Novel regulatory role of neuropilin-1 in endothelial-to-mesenchymal transition and fibrosis in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an intense fibrotic reaction termed tumor desmoplasia, which is in part responsible for its aggressiveness. Endothelial cells have been shown to display cellular plasticity in the form of endothelial-to-mesenchymal transition (EndMT) that serves as an important source of fibroblasts in pathological disorders, including cancer. Angiogenic co-receptor, neuropilin-1 (NRP-1) actively binds TGFβ1, the primary mediator of EndMT and is involved in oncogenic processes like epithelial-to-mesenchymal transition (EMT). NRP-1 and TGFβ1 signaling have been shown to be aberrantly up-regulated in PDAC. We report herein a positive correlation between NRP-1 levels, EndMT and fibrosis in human PDAC xenografts. Loss of NRP-1 in HUVECs limited TGFβ1-induced EndMT as demonstrated by gain of endothelial and loss of mesenchymal markers, while maintaining endothelial cell architecture. Knockdown of NRP-1 down-regulated TGFβ canonical signaling (pSMAD2) and associated pro-fibrotic genes. Overexpression of NRP-1 exacerbated TGFβ1-induced EndMT and up-regulated TGFβ signaling and expression of pro-fibrotic genes. In vivo, loss of NRP-1 attenuated tumor perfusion and size, accompanied by reduction in EndMT and fibrosis. This study defines a previously unrecognized role of NRP-1 in regulating TGFβ1-induced EndMT and fibrosis, and advocates NRP-1 as a therapeutic target to reduce tumor fibrosis and PDAC progression.

NRP-2 in tumor lymphangiogenesis and lymphatic metastasis

Neuropilin-2 (NRP-2) not only functions as a receptor for semaphorins, a family of neural axon guidance factors, but also interacts with VEGFs, a family of vascular endothelial growth factors. As an independent receptor or a co-receptor, NRP-2 binds to ligands VEGF-C/D, activates the VEGF-C/D-NRP-2 signaling axis, and further regulates lymphangiogenesis-associated factors in both lymphatic endothelial cells (LECs) and some tumor cells during tumor progression. Via VEGF-C/D-NRP-2 axis, NRP-2 induces LEC proliferation, reconstruction and lymphangiogenesis and subsequently promotes tumor cell migration, invasion and lymphatic metastasis. There are similarities and differences among NRP-1, NRP-2 and VEGFR-3 in chemical structure, ligand specificity, chromosomal location, soluble protein forms, cellular functions and expression profiles. High expression of NRP-2 in LECs and tumor cells has been observed in different anatomic sites, histological patterns and progression stages of various tumors, especially during tumor lymphangiogenesis and lymphatic metastasis, and therefore the NRP-2 and VEGF-C/D-NRP-2 axis are closely related to tumor development, progression, invasion, and metastasis. In addition, it is important for prognosis of tumor. The studies on NRP-2 targeted therapy have recently achieved some successes, utilizing NRP-2 blocking antibodies, NRP-2 inhibitory peptides, soluble NRP-2 antagonists, small molecule inhibitors and various NRP-2 gene therapeutic strategies.

TGF-β receptor I/II trafficking and signaling at primary cilia are inhibited by ceramide to attenuate cell migration and tumor metastasis

Signaling by the transforming growth factor-β (TGF-β) receptors I and II (TβRI/II) and the primary cilia-localized sonic hedgehog (Shh) pathway promote cell migration and, consequently, tumor metastasis. In contrast, the sphingolipid ceramide inhibits cell proliferation and tumor metastasis. We investigated whether ceramide metabolism inhibited TβRI/II trafficking to primary cilia to attenuate cross-talk between TβRI/II and the Shh pathway. We found that ceramide synthase 4 (CerS4)-generated ceramide stabilized the association between TβRI and the inhibitory factor Smad7, which limited the trafficking of TβRI/II to primary cilia. Expression of a mutant TβRI that signals but does not interact with Smad7 prevented the CerS4-mediated inhibition of migration in various cancer cells. Genetic deletion or knockdown of CerS4 prevented the formation of the Smad7-TβRI inhibitory complex and increased the association between TβRI and the transporter Arl6 through a previously unknown cilia-targeting signal (Ala31Thr32Ala33Leu34Gln35) in TβRI. Mutating the cilia-targeting signal abolished the trafficking of TβRI to the primary cilia. Localization of TβRI to primary cilia activated a key mediator of Shh signaling, Smoothened (Smo), which stimulated cellular migration and invasion. TβRI-Smo cross-talk at the cilia in CerS4-deficient 4T1 mammary cancer cells induced liver metastasis from orthotopic allografts in both wild-type and CerS4-deficient mice, which was prevented by overexpression of Smad7 or knockdown of intraflagellar transport protein 88 (IFT88). Overall, these data reveal a ceramide-dependent mechanism that suppresses cell migration and invasion by restricting TβRI/II-Shh signaling selectively at the plasma membrane of the primary cilium.

Tri-methylation of H3K79 is decreased in TGF-β1-induced epithelial-to-mesenchymal transition in lung cancer

BACKGROUND

The epithelial-to-mesenchymal transition (EMT) enables epithelial cancer cells to acquire mesenchymal features and contributes to metastasis and resistance to treatment. This process involves epigenetic reprogramming for gene expression. We explored global histone modifications during TGF-β1-induced EMT in two non-small cell lung cancer (NSCLC) cell lines and tested different epigenetic treatment to modulate or partially reverse EMT.

RESULTS

Loss of classical epithelial markers and gain of mesenchymal markers were verified in A549 and H358 cell lines during TGF-β1-induced EMT. In addition, we noticed increased expression of the axonal guidance protein semaphorin 3C (SEMA3C) and PD-L1 (programmed death-ligand 1) involved in the inhibition of the immune system, suggesting that both SEMA3C and PD-L1 could be the new markers of TGF-β1-induced EMT. H3K79me3 and H2BK120me1 were decreased in A549 and H358 cell lines after a 48-h TGF-β1 treatment, as well as H2BK120ac in A549 cells. However, decreased H3K79me3 was not associated with expression of the histone methyltransferase DOT1L. Furthermore, H3K79me3 was decreased in tumors compared in normal tissues and not associated with cell proliferation. Associations of histone deacetylase inhibitor (SAHA) with DOT1L inhibitors (EPZ5676 or SGC0946) or BET bromodomain inhibitor (PFI-1) were efficient to partially reverse TGF-β1 effects by decreasing expression of PD-L1, SEMA3C, and its receptor neuropilin-2 (NRP2) and by increasing epithelial markers such as E-cadherin.

CONCLUSION

Histone methylation was modified during EMT, and combination of epigenetic compounds with conventional or targeted chemotherapy might contribute to reduce metastasis and to enhance clinical responses.

Clusterin and neuropilin-2 as potential biomarkers of tumor progression in benzo[a]pyrene-transformed 16HBE cells xenografted nude mouse model

Benzo[a]pyrene (BaP) is a ubiquitous environment contaminant and its exposure could increase incidence of human lung cancer. In order to confirm and compare potential biomarkers of BaP-induce carcinogenesis and tumor progression, time-dependent changes of clusterin (CLU) and neuropilin-2 (NRP2) levels were evaluated in sera of BaP-transformed 16HBE cell line T-16HBE-C1 cells xenografted nude mice. Performance of CLU and NRP2 on tissue classification and tumor progression forecast was also calculated. Levels of CLU and NRP2 were significant elevated in both culture supernatant of T-16HBE-C1 cells and sera of T-16HBE-C1 cells xenografted nude mice compared with control. CLU and NRP2 were both found positively stained in tumor tissue. CLU and NRP2 alone could well predicate tumor progression in nude mice and CLU appeared to be more sensitive than NRP2. When both of them combined, performance of predication would improve. In conclusion, CLU and NRP2 could serve as potential biomarkers of tumor progression in nude mice xenografted with T-16HBE-C1 cells.

Epigenetic Regulation of the Epithelial to Mesenchymal Transition in Lung Cancer

Lung cancer is the leading cause of cancer deaths worldwide. It is an aggressive and devastating cancer because of metastasis triggered by enhanced migration and invasion, and resistance to cytotoxic chemotherapy. The epithelial to mesenchymal transition (EMT) is a fundamental developmental process that is reactivated in wound healing and a variety of diseases including cancer where it promotes migration/invasion and metastasis, resistance to treatment, and generation and maintenance of cancer stem cells. The induction of EMT is associated with reprogramming of the epigenome. This review focuses on major mechanisms of epigenetic regulation mainly in lung cancer with recent data on EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit ), the catalytic subunit of the PRC2 (Polycomb Group PcG), that behaves as an oncogene in lung cancer associated with gene repression, non-coding RNAs and the epitranscriptome.

Chinese medicine Bu-Fei decoction attenuates epithelial-mesenchymal transition of non-small cell lung cancer via inhibition of transforming growth factor β1 signaling pathway in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine Bu-Fei decoction (BFD) has been utilized to treat patients with Qi deficiency for decades, with the advantages of invigorating vital energy, clearing heat-toxin and moistening lung, etc. According to previous clinical experience and trials, BFD has been found to indeed improve life quality of lung cancer patients and prolong survival time. Nevertheless, little is known on its potential mechanisms so far. Being regarded as a pivotal cytokine in the tumor microenvironment, transforming growth factor β (TGF-β) stands out as a robust regulator of epithelial-mesenchymal transition (EMT), which is closely linked to tumor progression.

AIM OF THE STUDY

The present study was designed to explore whether BFD antagonized EMT via blocking TGF-β1-induced signaling pathway, and then help contribute to create a relatively steady microenvironment for confining lung cancer.

MATERIALS AND METHODS

This experiment was performed in lung adenocarcinoma A549 cells both in vitro and in vivo. In detail, the influences mediated by TGF-β1 alone or in combination with different concentrations of BFD on migration were detected by wound healing and transwell assays, and the effects of BFD on cell viability were determined by cell counting kit-8 (CCK-8) assay. TGF-β1, EMT relevant proteins and genes were evaluated by western blotting, confocal microscopy, quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC) and enzyme-linked immuno sorbent assay (ELISA). Female BALB/C nude mice were subcutaneously implanted A549 cells and given BFD by gavage twice daily for 28 days. The tumor volume was monitored every 4 days to draw growth curve. The tumor weight, expression levels of EMT-related protein in tumor tissues and TGF-β1 serum level were evaluated, respectively.

RESULTS

BFD only exerted minor effects on A549 cell proliferation and this was in accordance with the in vivo result, which showed that the tumor growth and weight were not be restrained by BFD administration. However, the data elucidated that BFD could dose-dependently suppress EMT induced by TGF-β1 in vitro via attenuating canonical Smad signaling pathway. In the A549 xenograft mouse model, BFD also inhibited protein markers that are associated with EMT and TGF-β1 secretion into serum.

CONCLUSIONS

Based on these above data, the conclusion could be put forward that BFD probably attenuated TGF-β1 mediated EMT in A549 cells via decreasing canonical Smad signaling pathway both in vitro and in vivo, which may help restrain the malignant phenotype induced by TGF-β1 in A549 cells to some extent.

Endometrial Stromal and Epithelial Cells Exhibit Unique Aberrant Molecular Defects in Patients With Endometriosis

CONTEXT

Endometriosis is a chronic inflammatory disease that causes pain and infertility in women of reproductive age.

OBJECTIVE

To investigate the pathologic pathways in endometrial stromal and epithelial cells that contribute to the manifestation of endometriosis.

DESIGN

In vitro cellular and molecular analyses of isolated eutopic endometrial stromal and epithelial cells.

METHODS

Eutopic stromal and epithelial cells from endometriotic and normal patients were isolated by fluorescence-activated cell sorting for paired sibling RNA sequencing and microRNA microarray. Aberrant pathways were identified using ingenuity pathway analysis networks and confirmed with in vitro modulation of the affected pathways in stromal and epithelial cell cultures.

RESULTS

Both stromal versus epithelial cell types and paired endometriotic versus normal samples exhibited distinct hierarchical clustering. Compared to normal samples, there were 151 and 215 differentially expressed genes in the endometriotic stromal and epithelial populations, respectively, and concomitantly 9 and 16 differentially expressed microRNAs. Overall, endometriotic stromal and epithelial cells revealed distinct defects. In endometriotic stromal cells, key decidualization genes Zinc finger E-box Binding protein 1 (ZEB1), Heart And Neural crest Derivatives expressed 2 (HAND2), WNT4, and Interleukin 15 (IL-15) were found to be downregulated and Periostin (POSTN) and Matrix Metallopeptidase 7 (MMP7) were upregulated. Specifically, ZEB1 was downregulated in stromal cells by aberrant elevation in miR-200b. In contrast, ZEB1 was found to be upregulated in endometriotic epithelial cells through associated upregulation of transforming growth factor β1 (TGFβ1), inducer of the TGFβ1-Bone Morphogenetic Protein 2 (BMP2)-MMP2-Prostaglandin-endoperoxide Synthase 2 (COX2)-ZEB1 pathway, which activates epithelial-mesenchymal transition.

CONCLUSION

Manifestation of endometriosis involves dysregulation of unique molecular pathways within the diseased endometrial stromal and epithelial cells in the endometrium. Targeting the cell type-specific defects may offer a novel approach to treating endometriosis.

Noncanonical GLI1 signaling promotes stemness features and in vivo growth in lung adenocarcinoma

Aberrant Hedgehog/GLI signaling has been implicated in a diverse spectrum of human cancers, but its role in lung adenocarcinoma (LAC) is still under debate. We show that the downstream effector of the Hedgehog pathway, GLI1, is expressed in 76% of LACs, but in roughly half of these tumors, the canonical pathway activator, Smoothened, is expressed at low levels, possibly owing to epigenetic silencing. In LAC cells including the cancer stem cell compartment, we show that GLI1 is activated noncanonically by MAPK/ERK signaling. Different mechanisms can trigger the MAPK/ERK/GLI1 cascade including KRAS mutation and stimulation of NRP2 by VEGF produced by the cancer cells themselves in an autocrine loop or by stromal cells as paracrine cross talk. Suppression of GLI1, by silencing or drug-mediated, inhibits LAC cells proliferation, attenuates their stemness and increases their susceptibility to apoptosis in vitro and in vivo. These findings provide insight into the growth of LACs and point to GLI1 as a downstream effector for oncogenic pathways. Thus, strategies involving direct inhibition of GLI1 may be useful in the treatment of LACs.

Downregulation of miR-218 contributes to epithelial-mesenchymal transition and tumor metastasis in lung cancer by targeting Slug/ZEB2 signaling

Epithelial–mesenchymal transition (EMT) has been recognized as a key element of cell migration and invasion in lung cancer; however, the underlying mechanisms are not fully elucidated. Recently, emerging evidence suggest that miRNAs have crucial roles in control of EMT and EMT-associated traits such as migration, invasion and chemoresistance. Here, we found that miR-218 expression levels were significantly downregulated in lung cancer tissues compared with adjacent non-cancerous tissues, and the levels of miR-218 were significantly associated with histological grades and lymph node metastasis. Overexpression of miR-218 inhibited cell migration and invasion as well as the EMT process. Of particular importance, miR-218 was involved in the metastatic process of lung cancer cells in vivo by suppressing local invasion and distant colonization. We identified Slug and ZEB2 as direct functional targets of miR-218. Inverse correlations were observed between miR-218 levels and Slug/ZEB2 levels in cancer tissue samples. In addition, overexpression of miR-218 in H1299 increased chemosensitivity of cells to cisplatin treatment through suppression of Slug and ZEB2. These findings highlight an important role of miR-218 in the regulation of EMT-related traits and metastasis of lung cancer in part by modulation of Slug/ZEB2 signaling, and provide a potential therapeutic strategy by targeting miR-218 in NSCLC.

The neuropilin 2 isoform NRP2b uniquely supports TGFβ-mediated progression in lung cancer

Neuropilins (NRP1 and NRP2) are co-receptors for heparin-binding growth factors and class 3 semaphorins. Different isoforms of NRP1 and NRP2 are produced by alternative splicing. We found that in non-small cell lung cancer (NSCLC) cell lines, transforming growth factor-β (TGFβ) signaling preferentially increased the abundance of NRP2b. NRP2b and NRP2a differ only in their carboxyl-terminal regions. Although the presence of NRP2b inhibited cultured cell proliferation and primary tumor growth, NRP2b enhanced cellular migration, invasion into Matrigel, and tumorsphere formation in cultured cells in response to TGFβ signaling and promoted metastasis in xenograft mouse models. These effects of overexpressed NRP2b contrast with the effects of overexpressed NRP2a. Hepatocyte growth factor (HGF)-induced phosphorylation of the kinase AKT was specifically promoted by NRP2b, whereas inhibiting the HGF receptor MET attenuated NRP2b-dependent cell migration. Unlike NRP2a, NRP2b did not bind the PDZ domain scaffolding protein GAIP carboxyl terminus-interacting protein (GIPC1) and only weakly recruited phosphatase and tensin homolog (PTEN), potentially explaining the difference between NRP2b-mediated and NRP2a-mediated effects. Analysis of NSCLC patient tumors showed that NRP2b abundance correlated with that of the immune cell checkpoint receptor ligand PD-L1 as well as with epithelial-to-mesenchymal transition (EMT) phenotypes in the tumors, acquired resistance to epidermal growth factor receptor (EGFR) inhibitors, disease progression, and poor survival in patients. NRP2b knockdown attenuated the acquisition of resistance to the EGFR inhibitor gefitinib in cultured NSCLC cells. Thus, in NSCLC, NRP2b contributed to the oncogenic response to TGFβ and correlated with tumor progression in patients.

131I-labeled monoclonal antibody targeting neuropilin receptor type-2 for tumor SPECT imaging

As a co-receptor for vascular endothelial growth factor‑3 (VEGF‑3), neuropilin receptor type‑2 (NRP‑2) plays a central role in lymphangiogenesis and angiogenesis. Recently, mounting data of evidence show that NRP‑2 is overexpressed in several human cancers, and its overexpression is often associated with poor prognosis. Therefore, it is necessary for us to develop an affinity reagent for noninvasive imaging of NRP‑2 expression because it may be possible to provide early cancer diagnosis, more accurate prognosis, and better treatment planning. Due to their high affinity, and specificity, monoclonal antibodies (mAbs) have been considered attractive candidates for targeted cancer therapy and diagnostics. We recently generated and validated a monoclonal antibody that specifically binds NRP‑2 b1b2 domain with no cross‑reactivity to NRP‑1 b1b2 domain, also known to be overexpressed in a variety of cancers. Here, we developed a single photon emission computed tomography (SPECT) probe for imaging NRP‑2- positive tumors. Anti‑NRP‑2 monoclonal antibodies were prepared by hybridomas and were labeled with iodine‑131 by chloramine‑T method. The in vitro physicochemical properties of 131I‑anti‑NRP‑2 mAb was determined. Binding affinity and specificity of 131I‑anti‑NRP‑2 mAb to NRP‑2 were assessed using human lung adenocarcinoma A549 cells. Biodistribution and SPECT studies were performed in mice bearing A549 tumor xenografts to evaluate the in vivo performance of 131I‑anti‑NRP‑2 mAb. The preparation of anti‑NRP‑2 mAb was completed successfully by hybridoma with high purity (>95%) and specific for NRP‑2 b1b2 domain, but not NRP‑1 b1b2 domain. The radiosynthesis of 131I‑anti‑NRP‑2 mAb was completed successfully within 60 min with high labelling efficiency (94.69±3.63%), and radiochemical purity (98.56±0.48%). The resulting probe, 131I‑anti‑NRP‑2 mAb displayed excellent stability in PBS solution during 24-72 h. 131I‑anti‑NRP‑2 mAb showed high binding affinity with A549 cells (96.6±1.44 nM). In vivo biodistribution and SPECT studies demonstrated targeting of A549 glioma xenografts was NRP‑2 specific. The tumor uptake was 5.86±0.27% ID/g at 6 h, and kept at high level of 4.64±0.82% ID/g at 72 h‑post‑injection. The tumor to contralateral muscle ratio (T/NT) was 2.08±0.33 at 6 h, and reached the highest level of 3.83±0.18 at 72 h after injection. SPECT imaging studies revealed that 131I‑anti‑NRP‑2 mAb could clearly identify A549 tumors with good contrast, especially at 48‑72 h after injection. In conclusion, this study demonstrates that 131I‑anti‑NRP‑2 mAb exhibited highly selective uptake in NRP‑2‑expressing tumors, and may provide a promising SPECT probe for imaging NRP‑2 positive tumors.

Inflammation and Lymphedema Are Exacerbated and Prolonged by Neuropilin 2 Deficiency

The vasculature influences the progression and resolution of tissue inflammation. Capillaries express vascular endothelial growth factor (VEGF) receptors, including neuropilins (NRPs), which regulate interstitial fluid flow. NRP2, a receptor of VEGFA and semaphorin (SEMA) 3F ligands, is expressed in the vascular and lymphatic endothelia. Previous studies have demonstrated that blocking VEGF receptor 2 attenuates VEGFA-induced vascular permeability. The inhibition of NRP2 was hypothesized to decrease vascular permeability as well. Unexpectedly, massive tissue swelling and edema were observed in Nrp2^-/- mice compared with wild-type littermates after delayed-type hypersensitivity reactions. Vascular permeability was twofold greater in inflamed blood vessels in Nrp2-deficient mice compared to those in Nrp2-intact littermates. The addition of exogenous SEMA3F protein inhibited vascular permeability in Balb/cJ mice, suggesting that the loss of endogenous Sema3F activity in the Nrp2-deficient mice was responsible for the enhanced vessel leakage. Functional lymphatic capillaries are necessary for draining excess fluid after inflammation; however, Nrp2-mutant mice lacked superficial lymphatic capillaries, leading to 2.5-fold greater fluid retention and severe lymphedema after inflammation. In conclusion, Nrp2 deficiency increased blood vessel permeability and decreased lymphatic vessel drainage during inflammation, highlighting the importance of the NRP2/SEMA3F pathway in the modulation of tissue swelling and resolution of postinflammatory edema.

MicroRNA-331-3p Suppresses Cervical Cancer Cell Proliferation and E6/E7 Expression by Targeting NRP2

Aberrant expression of microRNAs (miRNAs) is involved in the development and progression of various types of cancers. In this study, we investigated the role of miR-331-3p in cell proliferation and the expression of keratinocyte differentiation markers of uterine cervical cancer cells. Moreover, we evaluated whether neuropilin 2 (NRP2) are putative target molecules that regulate the human papillomavirus (HPV) related oncoproteins E6 and E7. Cell proliferation in the human cervical cancer cell lines SKG-II, HCS-2, and HeLa was assessed using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) assay. Cellular apoptosis was measured using the TdT-mediated dUTP nick end labeling (TUNEL) and Annexin V assays. Quantitative RT-PCR was used to measure the messenger RNA (mRNA) expression of the NRP2, E6, E7, p63, and involucrin (IVL) genes. A functional assay for cell growth was performed using cell cycle analyses. Overexpression of miR-331-3p inhibited cell proliferation, and induced G2/M phase arrest and apoptosis in SKG-II, HCS-2 and HeLa cells. The luciferase reporter assay of the NRP2 3′-untranslated region revealed the direct regulation of NRP2 by miR-331-3p. Gene expression analyses using quantitative RT-PCR in SKG-II, HCS-2, and HeLa cells overexpressing miR-331-3p or suppressing NRP2 revealed down-regulation of E6, E7, and p63 mRNA and up-regulation of IVL mRNA. Moreover, miR-331-3p overexpression was suppressed NRP2 expression in protein level. We showed that miR-331-3p and NRP2 were key effectors of cell proliferation by regulating the cell cycle, apoptosis. NRP-2 also regulates the expression of E6/E7 and keratinocyte differentiation markers. Our findings suggest that miR-331-3p has an important role in regulating cervical cancer cell proliferation, and that miR-331-3p may contribute to keratinocyte differentiation through NRP2 suppression. miR-331-3p and NRP2 may contribute to anti-cancer effects.

CCR7 enhances TGF-β1-induced epithelial-mesenchymal transition and is associated with lymph node metastasis and poor overall survival in gastric cancer

CCR7 is a G protein-coupled chemokine receptor. In this study, we used immunohistochemistry with tissue microarrays to measure CCR7 expression in tumor specimens from 122 patients with gastric cancer. We show that CCR7 expression is associated with lymph node metastasis (P = 0.022) and overall survival (OS; P = 0.025), and is an independent factor associated with poorer overall survival (P = 0.032). The CCR7 mechanism was predicted based on bioinformatic analysis and verified in gastric cancer cell lines and primary tumor samples. The data show that CCR7 contributes to TGF-β1-induced epithelial-mesenchymal transition (EMT) and that the effects of TGF-β1 are inhibited by a CCR7 neutralizing antibody or a NF-κB inhibitor. Increased TGF-β1 expression was accompanied by nuclear localization of NF-κB-p65 and higher levels of the mesenchymal marker vimentin in human gastric cancer samples. We conclude that the CCR7 axis mediates TGF-β1-induced EMT via crosstalk with NF-κB signaling, facilitating lymph node metastasis and poorer overall survival in patients with gastric cancer. These findings suggest CCR7 is a novel prognostic indicator and a potential target for gastric cancer therapy.

Preparation, Purification, and Identification of a Monoclonal Antibody Against NRP2 b1b2 Domain

First identified as a high-affinity kinase-deficient receptor for class-3 semaphorins and vascular endothelial growth factor (VEGF) families, Neuropilin2 (NRP2) is a transmembrane non-tyrosine-kinase glycoprotein that has a vital function in neuronal patterning. Furthermore, NRP2 expression is often upregulated in cancer tissues and correlated with poor prognosis. In the present study, we report the establishment of a monoclonal antibody specific for NRP2b1b2 domain (NRP2 MAb) through hybridoma method. NRP2 MAb is measured to have a titer of 5.12 × 10(5) against NRP2b1b2 in indirect ELISA. Western blotting, flow cytometry, and immunofluorescence analysis indicate that NRP2 MAb can combine full-length NRP2 in LoVo and SW480 cells. Besides helping further understand NRP2-related pathological mechanisms and cell-signaling pathways, NRP2 MAb may act as a therapeutic agent for cancer in the future.

Mechanisms of TGFβ-Induced Epithelial-Mesenchymal Transition

Transitory phenotypic changes such as the epithelial–mesenchymal transition (EMT) help embryonic cells to generate migratory descendants that populate new sites and establish the distinct tissues in the developing embryo. The mesenchymal descendants of diverse epithelia also participate in the wound healing response of adult tissues, and facilitate the progression of cancer. EMT can be induced by several extracellular cues in the microenvironment of a given epithelial tissue. One such cue, transforming growth factor β (TGFβ), prominently induces EMT via a group of specific transcription factors. The potency of TGFβ is partly based on its ability to perform two parallel molecular functions, i.e. to induce the expression of growth factors, cytokines and chemokines, which sequentially and in a complementary manner help to establish and maintain the EMT, and to mediate signaling crosstalk with other developmental signaling pathways, thus promoting changes in cell differentiation. The molecules that are activated by TGFβ signaling or act as cooperating partners of this pathway are impossible to exhaust within a single coherent and contemporary report. Here, we present selected examples to illustrate the key principles of the circuits that control EMT under the influence of TGFβ.

Neuropilin-2 promotes tumourigenicity and metastasis in oesophageal squamous cell carcinoma through ERK-MAPK-ETV4-MMP-E-cadherin deregulation

Oesophageal squamous cell carcinoma (ESCC) is the most common histological subtype of oesophageal cancer. The disease is particularly prevalent in southern China. The incidence of the disease is on the rise and its overall survival rate remains dismal. Identification and characterization of better molecular markers for early detection and therapeutic targeting are urgently needed. Here, we report levels of transmembrane and soluble neuropilin-2 (NRP2) to be significantly up-regulated in ESCC, and to correlate positively with advanced tumour stage, lymph node metastasis, less favourable R category and worse overall patient survival. NRP2 up-regulation in ESCC was in part a result of gene amplification at chromosome 2q. NRP2 overexpression promoted clonogenicity, angiogenesis and metastasis in ESCC in vitro, while NRP2 silencing by lentiviral knockdown or neutralizing antibody resulted in a contrary effect. This observation was extended in vivo in animal models of subcutaneous tumourigenicity and tail vein metastasis. Mechanistically, overexpression of NRP2 induced expression of ERK MAP kinase and the transcription factor ETV4, leading to enhanced MMP-2 and MMP-9 activity and, as a consequence, suppression of E-cadherin. In summary, NRP2 promotes tumourigenesis and metastasis in ESCC through deregulation of ERK-MAPK-ETV4-MMP-E-cadherin signalling. NRP2 represents a potential diagnostic or prognostic biomarker and therapeutic target for ESCC. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

DNA Methylation in Newborns and Maternal Smoking in Pregnancy: Genome-wide Consortium Meta-analysis

Epigenetic modifications, including DNA methylation, represent a potential mechanism for environmental impacts on human disease. Maternal smoking in pregnancy remains an important public health problem that impacts child health in a myriad of ways and has potential lifelong consequences. The mechanisms are largely unknown, but epigenetics most likely plays a role. We formed the Pregnancy And Childhood Epigenetics (PACE) consortium and meta-analyzed, across 13 cohorts (n = 6,685), the association between maternal smoking in pregnancy and newborn blood DNA methylation at over 450,000 CpG sites (CpGs) by using the Illumina 450K BeadChip. Over 6,000 CpGs were differentially methylated in relation to maternal smoking at genome-wide statistical significance (false discovery rate, 5%), including 2,965 CpGs corresponding to 2,017 genes not previously related to smoking and methylation in either newborns or adults. Several genes are relevant to diseases that can be caused by maternal smoking (e.g., orofacial clefts and asthma) or adult smoking (e.g., certain cancers). A number of differentially methylated CpGs were associated with gene expression. We observed enrichment in pathways and processes critical to development. In older children (5 cohorts, n = 3,187), 100% of CpGs gave at least nominal levels of significance, far more than expected by chance (p value < 2.2 × 10(-16)). Results were robust to different normalization methods used across studies and cell type adjustment. In this large scale meta-analysis of methylation data, we identified numerous loci involved in response to maternal smoking in pregnancy with persistence into later childhood and provide insights into mechanisms underlying effects of this important exposure.

Label-free quantitative proteomic analysis of benzo(a)pyrene-transformed 16HBE cells serum-free culture supernatant and xenografted nude mice sera

To screen potential biomarkers of benzo(a)pyrene (BaP)-induced lung cancer, the proteomic profiles of BaP-transformed 16HBE cell line T-16HBE-C1 cells serum-free culture supernatant and xenografted nude mice sera were compared with those of 16HBE group by utilizing label-free quantitative proteomic strategy. By employing nano-LC-MS/MS technology followed by MaxQuant and Perseus processing, 489 differentially expressed proteins were identified between T-16HBE-C1 and 16HBE cells serum-free culture supernatant, and 49 significantly up-regulated proteins were identified in T-16HBE-C1 xenografted nude mice sera. Three proteins neuropilin-2 (NRP2), clusterin (CLU) and A-kinase anchor protein 12 (AKAP12) were up-regulated in the serum-free culture supernatant of T-16HBE-C1 cells. These 3 human proteins were present in the sera of nude mice xenografted with T-16HBE-C1 cells, but were undetectable in mice xenografted with 16HBE cells. The proteomic results of NRP2 and AKAP12 were confirmed by Western blotting and enzyme-linked immunosorbent assays, respectively. Moreover, the serum NRP2 levels were significantly elevated at the 4th day after tumor cell implantation and showed good positive correlation with tumor growth characterized by tumor volume. In conclusion, serum NRP2, CLU and AKAP12 could be potential biomarkers of BaP-induced lung cancer. The proteomic results will gain deeper insights into the mechanisms of BaP-induced carcinogenesis.

Blocking the epithelial-to-mesenchymal transition pathway abrogates resistance to anti-folate chemotherapy in lung cancer

Anticancer therapies currently used in the clinic often can neither eradicate the tumor nor prevent disease recurrence due to tumor resistance. In this study, we showed that chemoresistance to pemetrexed, a multi-target anti-folate (MTA) chemotherapeutic agent for non-small cell lung cancer (NSCLC), is associated with a stem cell-like phenotype characterized by an enriched stem cell gene signature, augmented aldehyde dehydrogenase activity and greater clonogenic potential. Mechanistically, chemoresistance to MTA requires activation of epithelial-to-mesenchymal transition (EMT) pathway in that an experimentally induced EMT per se promotes chemoresistance in NSCLC and inhibition of EMT signaling by kaempferol renders the otherwise chemoresistant cancer cells susceptible to MTA. Relevant to the clinical setting, human primary NSCLC cells with an elevated EMT signaling feature a significantly enhanced potential to resist MTA, whereas concomitant administration of kaempferol abrogates MTA chemoresistance, regardless of whether it is due to an intrinsic or induced activation of the EMT pathway. Collectively, our findings reveal that a bona fide activation of EMT pathway is required and sufficient for chemoresistance to MTA and that kaempferol potently regresses this chemotherapy refractory phenotype, highlighting the potential of EMT pathway inhibition to enhance chemotherapeutic response of lung cancer.