Emerging roles and mechanisms of semaphorins activity in cancer

SEMA3C promotes thyroid cancer via the Wnt/β-catenin pathway

Semaphorin 3C (SEMA3C) regulates the progression of several tumors. However, the role of SEMA3C in thyroid cancer remains unknow. In the present study, SEMA3C was overexpressed or knocked down in thyroid cancer cell lines BCPAP and IHH-4. It was found that SEMA3C promoted the cell migration, invasion, and mesenchymal-epithelial transition (EMT) process. SEMA3C overexpression enhanced tumor cell stemness, while SEMA3C knockdown showed the opposite effects. In vivo experiments suggested that SEMA3C accelerated the tumor growth and metastasis. Moreover, SEMA3C enhanced β-catenin nuclear translocation. When cells were treated with Dickkopf-1 (DKK1), an inhibitor of Wnt/β-catenin pathway, the promoting effects of SEMA3C on cell migration and stemness were offset. Wnt/β-catenin pathway mediated the roles of SEMA3C in thyroid cancer. Additionally, an upstream regulator of SEMA3C was identified. E1A binding protein P300 (P300) was found to increase the histone three lysine 27 acetylation (H3K27ac) level of SEMA3C, promoting its transcriptional activation. Therefore, we clarify that SEMA3C exerts a tumor-promoting effect on thyroid cancer, and Wnt/β-catenin pathway is the critical downstream pathway.

Construction and validation of a prognostic signature based on microvascular invasion and immune-related genes in hepatocellular carcinoma

BACKGROUND

Microvascular invasion (MVI) is an independent risk factor of poor prognosis in hepatocellular carcinoma (HCC) and can be used to guide the diagnosis and treatment of HCC. The immune system serves as an integral role in the incidence and progression of HCC. However, the molecular biology correlation between MVI and tumor immunity and the value of combining the two parameters to predict patient prognosis and HCC response to treatment remain to be evaluated.

RESULTS

In this study, we used univariate Cox regression analysis and least absolute shrinkage and selection operator (LASSO) Cox analysis to establish the MVI and immune-related gene index (MIRGPI) including eight genes. We demonstrated that the MIRGPI was an independent risk factor in predicting the prognosis of HCC. Subsequently, our research established a nomogram model combining pathologic characteristics and verified its good clinical application value. In addition, our study found that the TP53 gene had a higher mutation frequency and a lower degree of immune infiltration in the high-risk group. The low-risk group had higher sensitivity to immunotherapy, sorafenib, and TACE treatment, and the high-risk group had higher sensitivity to common chemotherapeutic agents. Finally, SEMA3C was found to facilitate the proliferation, migration and invasive ability of HCC by in vitro and in vivo experiments, and its mechanism may be associated with the activation of the NF-Κb/EMT signaling pathway.

CONCLUSIONS

In summary, the MIRGPI signature we developed is a reliable marker for the prediction of prognosis and treatment response, and is important for the prognostic assessment and individualized treatment of HCC.

Semaphorin 3F (SEMA3F) influences patient survival in esophageal adenocarcinoma

In esophageal adenocarcinoma, the presence of lymph node metastases predicts patients' survival even after curative resection. Currently, there is no highly accurate marker for detecting the presence of lymph node metastasis. The SEMA3F/NRP2 axis was initially characterized in axon guidance and recent evidence has revealed its significant involvement in lymphangiogenesis, angiogenesis, and carcinogenesis. Hence, the objective of this study was to elucidate the roles of SEMA3F and its receptor NRP2 in esophageal adenocarcinoma. We conducted an immunohistochemical evaluation of SEMA3F and NRP2 protein expression in 776 patients with esophageal adenocarcinoma who underwent Ivor-Lewis esophagectomy at the University Hospital of Cologne. Total and positive cancer cell counts were digitally analyzed using QuPath and verified by experienced pathologists to ensure accuracy. Positive expression was determined as a cell percentage exceeding the 50th percentile threshold. In our cohort, patients exhibiting SEMA3F positive expression experience significantly lower pT- and pN-stages. In contrast, positive NRP2 expression is associated with the presence of lymph node metastases. Survival analyses showed that the expression status of NRP2 had no impact on patient survival. However, SEMA3F positivity was associated with a favorable patient survival outcome (median OS: 38.9 vs. 26.5 months). Furthermore, SEMA3F could be confirmed as an independent factor for better patient survival in patients with early tumor stage (pT1N0-3: HR = 0.505, p = 0.014, pT1-4N0: HR = 0.664, p = 0.024, pT1N0: HR = 0.483, p = 0.040). In summary, SEMA3F emerges as an independent predictor for a favorable prognosis in patients with early-stage esophageal adenocarcinoma. Additionally, NRP2 expression is linked to a higher risk of lymph node metastases occurrence. We hypothesize that low SEMA3F expression could identify patients with early-stage tumors who might benefit from more aggressive treatment options or intensified follow-up. Furthermore, SEMA3F and its associated pathways should be explored as potential tumor-suppressing agents.

Role of Semaphorin 3A in common psychiatric illnesses such as schizophrenia, depression, and anxiety

With societal development and an ageing population, psychiatric disorders have become a common cause of severe and long-term disability and socioeconomic burdens worldwide. Semaphorin 3A (Sema-3A) is a secreted glycoprotein belonging to the semaphorin family. Sema-3A is well known as an axon guidance factor in the neuronal system and a potent immunoregulator at all stages of the immune response. It is reported to have various biological functions and is involved in many human diseases, including autoimmune diseases, angiocardiopathy, osteoporosis, and tumorigenesis. The signals of sema-3A involved in the pathogenesis of these conditions, are transduced through its cognate receptors and diverse downstream signalling pathways. An increasing number of studies show that sema-3A plays important roles in synaptic and dendritic development, which are closely associated with the pathophysiological mechanisms of psychiatric disorders, including schizophrenia, depression, and autism, suggesting the involvement of sema-3A in the pathogenesis of mental diseases. This indicates that mutations in sema-3A and alterations in its receptors and signalling may compromise neurodevelopment and predispose patients to these disorders. However, the role of sema-3A in psychiatric disorders, particularly in regulating neurodevelopment, remains elusive. In this review, we summarise the recent progress in understanding sema-3A in the pathogenesis of mental diseases and highlight sema-3A as a potential target for the prevention and treatment of these diseases.

The role of neuropilin in bone/cartilage diseases

Bone remodeling is the balance between osteoblasts and osteoclasts. Bone diseases such as osteoporosis and osteoarthritis are associated with imbalanced bone remodeling. Skeletal injury leads to limited motor function and pain. Neurophilin was initially identified in axons, and its various ligands and roles in bone remodeling, angiogenesis, neuropathic pain and immune regulation were later discovered. Neurophilin promotes osteoblast mineralization and inhibits osteoclast differentiation and its function. Neuropolin-1 provides channels for immune cell chemotaxis and cytokine diffusion and leads to pain. Neuropolin-1 regulates the proportion of T helper type 17 (Th17) and regulatory T cells (Treg cells), and affects bone immunity. Vascular endothelial growth factors (VEGF) combine with neuropilin and promote angiogenesis. Class 3 semaphorins (Sema3a) compete with VEGF to bind neuropilin, which reduces angiogenesis and rejects sympathetic nerves. This review elaborates on the structure and general physiological functions of neuropilin and summarizes the role of neuropilin and its ligands in bone and cartilage diseases. Finally, treatment strategies and future research directions based on neuropilin are proposed.

A genome-wide association study on hematopoietic stem cell transplantation reveals novel genomic loci associated with transplant outcomes

Introduction

Data on genomic susceptibility for adverse outcomes after hematopoietic stem cell transplantation (HSCT) for recipients are scarce.

Methods

We performed a genome wide association study (GWAS) to identify genes associated with survival/mortality, relapse, and severe graft-versus-host disease (sGvHD), fitting proportional hazard and subdistributional models to data of n=1,392 recipients of European ancestry from three centres.

Results

The single nucleotide polymorphism (SNP) rs17154454, intronic to the neuronal growth guidant semaphorin 3C gene (SEMA3C), was genome-wide significantly associated with event-free survival (p=7.0x10-8) and sGvHD (p=7.5x10-8). Further associations were detected for SNPs in the Paxillin gene (PXN) with death without prior relapse or sGvHD, as well as for SNPs of the Plasmacytoma Variant Translocation 1 gene (PVT1, a long non-coding RNA gene), the Melanocortin 5 Receptor (MC5R) gene and the WW Domain Containing Oxidoreductase gene (WWOX), all associated with the occurrence of sGvHD. Functional considerations support the observed associations.

Discussion

Thus, new genes were identified, potentially influencing the outcome of HSCT.

New Promising Routes in Peptic Ulcers: Toll-like Receptors and Semaphorins

Peptic ulcers (PU) are one of the commonest yet problematic diseases found to be existing in the majority of the population. Today, drugs from a wide range of therapeutic classes are available for the management of the disease. Still, the complications of the condition are difficult to tackle and the side effect profile is quite a concern. The literature indicates that Toll-like receptors (TLRs) and Semaphorins (SEMAs) have been under study for their various pharmacological actions over the past few decades. Both these signalling pathways are found to regulate immunological and inflammatory responses. Moreover, receptors and signalling molecules from the family of TLRs and SEMAs are found to have bacterial recognition and antibacterial properties which are essential in eradicating Helicobacter pylori (H. pylori), one of the major causative agents of PU. Our understanding of SEMAs, a class of proteins involved in cell signalling, is relatively less developed compared to TLRs, another class of proteins involved in the immune response. SEMAs and TLRs play different roles in biological processes, with SEMAs primarily involved in guiding cell migration and axon guidance during development, while TLRs are responsible for recognizing pathogens and initiating an immune response. Here, in this review, we will discuss in detail the signalling cascade of TLRs and SEMAs and thereby understand its association with PU for future therapeutic targeting. The review also aims at providing an overview of the study that has been into exploring the role of these signalling pathways in the management of PU.

Sema3A Alleviates the Malignant Behaviors of Gastric Cancer Cells by Inhibiting NRP-1

AIMS AND OBJECTIVES

Semaphorin3A (Sema3a) is lowly expressed in the peripheral blood of gastric cancer patients, suggesting Sema3a may be involved in the progression of gastric cancer. Nevertheless, the specific role and the potential regulatory mechanism of Sema3a in gastric cancer is still obscure. Neuropilin-1 (NRP-1) has been reported to interact with Sema3a; herein, we intended to reveal the role and regulatory mechanism of Sema3a/neuropilin-1 (NRP-1) in gastric cancer progression.

METHODS

Cell transfection was carried out to regulate gene expression. CCK-8 and colony formation assays were applied to estimate cell proliferation. Scratch assay and transwell assay were conducted to assess the cell migration and invasion abilities. Angiogenesis ability was assessed using a tubule-forming assay. The expression of corresponding genes and proteins were detected by RT-qPCR and western blot, respectively.

RESULTS

Data showed that Sema3a was downregulated in gastric cancer cells and NRP-1 was upregulated. Sema3a overexpression repressed NRP-1 level in AGS cells. Overexpression of Sema3a inhibited cell proliferation, migration, and invasion abilities as well as epithelial-mesenchymal transition (EMT) of AGS cells. Overexpression of Sema3a inhibited tube formation and reduced the expression of VEGFA/VEGFR2 in AGS cells. However, the effects of Sema3a overexpression on the malignant behaviors in AGS cells were partly reversed by NRP-1 overexpression. Additionally, Sema3a overexpression enhanced the inhibitory effects of Ramucirumab, an anti-VEGFR2 agent, on the proliferative, migratory, and invasive capabilities as well as EMT in AGS cells.

CONCLUSION

In conclusion, Sema3a alleviates the proliferation, migration, invasion, and angiogenesis capabilities of gastric cancer cells via repressing NRP-1. This finding may provide potential targets for gastric cancer therapy.

Semaphorin 3A influences neuronal processes that are altered in patients with autism spectrum disorder: Potential diagnostic and therapeutic implications

Autism spectrum disorder (ASD) is a pervasive disorder that most frequently manifests in early childhood and lasts for their entire lifespan. Several behavioural traits characterise the phenotype of patients with ASD, including difficulties in reciprocal social communication as well as compulsive/repetitive stereotyped verbal and non-verbal behaviours. Although multiple hypotheses have been proposed to explain the aetiology of ASD and many resources have been used to improve our understanding of ASD, several aspects remain largely unexplored. Class 3 semaphorins (SEMA3) are secreted proteins involved in the organisation of structural and functional connectivity in the brain that regulate synaptic and dendritic development. Alterations in brain connectivity and aberrant neuronal development have been described in some patients with ASD. Mutations and polymorphisms in SEMA3A and alterations in its receptors and signalling have been associated with some neurological disorders such as schizophrenia and epilepsy, which are comorbidities in ASD, but also with ASD itself. In addition, SEMA3A is a key regulator of the immune response and neuroinflammatory processes, which have been found to be dysregulated in mothers of children who develop ASD and in affected patients. In this review, we highlight neurodevelopmental-related processes in which SEMA3A is involved, which are altered in ASD, and provide a viewpoint emphasising the development of strategies targeting changes in the SEMA3A signal to identify patterns of anomalies distinctive of ASD or to predict the prognosis of affected patients.

The Glioblastoma CircularRNAome

Glioblastoma remains one of the most aggressive cancers of the brain, warranting new methods for early diagnosis and more efficient treatment options. Circular RNAs (circRNAs) are rather new entities with increased stability compared to their linear counterparts that interact with proteins and act as microRNA sponges, among other functions. Herein, we provide a critical overview of the recently described glioblastoma-related circRNAs in the literature, focusing on their roles on glioblastoma cancer cell proliferation, survival, migration, invasion and metastasis, metabolic reprogramming, and therapeutic resistance. The main roles of circRNAs in regulating cancer processes are due to their regulatory roles in essential oncogenic pathways, including MAPK, PI3K/AKT/mTOR, and Wnt, which are influenced by various circRNAs. The present work pictures the wide implication of circRNAs in glioblastoma, thus highlighting their potential as future biomarkers and therapeutic targets/agents.

Plexins as Regulators of Cancer Cell Proliferation, Migration, and Invasivity

Plexins are a family of nine single-pass transmembrane receptors with a conserved GTPase activating protein (GAP) domain. The plexin family is divided into four subfamilies: Type-A, type-B, type-C, and type-D plexins. Plexins function as receptors for axon guidance factors of the semaphorin family. The semaphorin gene family contains 22 genes that are divided into eight subclasses of which subclasses three to seven represent vertebrate semaphorins. The plexins and their semaphorin ligands have important roles as regulators of angiogenesis, cancer proliferation, and metastasis. Class 3 semaphorins, with the exception of sema3E, are the only semaphorins that do not bind directly to plexins. In order to transduce their signals, they bind instead to complexes consisting of receptors of the neuropilin family and various plexins. Some plexins also form complexes with tyrosine-kinase receptors such as the epidermal growth factor receptor ErbB2, the mesenchymal epithelial transition factor receptor (MET), and the Vascular endothelial growth factor receptor 2 (VEGFR2) and, as a result, can modulate cell proliferation and tumor progression. This review focuses on the roles of the different plexins in the control of cancer cell proliferation and invasiveness. Plexins also affect tumor progression and tumor metastasis by indirect mechanisms, such as modulation of angiogenesis and immune responses. However, these topics are not covered in the present review.