The semaphorins and their receptors as modulators of tumor progression

Sema4D Knockout Attenuates Choroidal Neovascularization by Inhibiting M2 Macrophage Polarization Via Regulation of the RhoA/ROCK Pathway

Purpose

The aim of this study was to elucidate the role of Sema4D in the pathogenesis of senescence-associated choroidal neovascularization (CNV) and to explore its underlying mechanisms.

Methods

In this study, we utilized a model of laser-induced CNV in both young (3 months old) and old (18 months old) mice, including those with or without Sema4D knockout. The expression and localization of Sema4D in CNV were assessed using PCR, Western blot, and immunostaining. Subsequently, the morphological and imaging examinations were used to evaluate the size of CNV and vascular leakage. Finally, the expression of M2 markers, senescence-related markers, and molecules involved in the RhoA/ROCK pathway was detected.

Results

We found that Sema4D was predominantly expressed in macrophages within CNV lesions, and both the mRNA and protein levels of Sema4D progressively increased following laser photocoagulation, a trend more pronounced in old mice. Moreover, Sema4D knockout markedly inhibited M2 polarization in senescent macrophages and reduced the size and leakage of CNV, particularly in aged mice. Mechanistically, aging was found to upregulate RhoA/ROCK signaling, and knockout of Sema4D effectively suppressed the activation of this pathway, with more significant effects observed in aged mice.

Conclusions

Our findings revealed that the deletion of Sema4D markedly inhibited M2 macrophage polarization through the suppression of the RhoA/ROCK pathway, ultimately leading to the attenuation of senescence-associated CNV. These data indicate that targeting Sema4D could offer a promising approach for gene editing therapy in patients with neovascular age-related macular degeneration.

Based on scRNA-seq and bulk RNA-seq to establish tumor immune microenvironment-associated signature of skin melanoma and predict immunotherapy response

Skin cutaneous melanoma (SKCM), a form of skin cancer, ranks among the most formidable and lethal malignancies. Exploring tumor microenvironment (TME)-based prognostic indicators would help improve the efficacy of immunotherapy for SKCM patients. This study analyzed SKCM scRNA-seq data to cluster non-malignant cells that could be used to explore the TME into nine immune/stromal cell types, including B cells, CD4 T cells, CD8 T cells, dendritic cells, endothelial cells, Fibroblasts, macrophages, neurons, and natural killer (NK) cells. Using data from The Cancer Genome Atlas (TCGA), we employed SKCM expression profiling to identify differentially expressed immune-associated genes (DEIAGs), which were then incorporated into weighted gene co-expression network analysis (WGCNA) to investigate TME-associated hub genes. Discover candidate small molecule drugs based on pivotal genes. Tumor immune microenvironment-associated genes (TIMAGs) for constructing TIMAS were identified and validated. Finally, the characteristics of TIAMS subgroups and the ability of TIMAS to predict immunotherapy outcomes were analyzed. We identified five TIMAGs (CD86, CD80, SEMA4D, C1QA, and IRF1) and used them to construct TIMAS. In addition, five potential SKCM drugs were identified. The results showed that TIMAS-low patients were associated with immune-related signaling pathways, high MUC16 mutation frequency, high T cell infiltration, and M1 macrophages, and were more favorable for immunotherapy. Collectively, TIMAS constructed by comprehensive analysis of scRNA-seq and bulk RNA-seq data is a promising marker for predicting ICI treatment outcomes and improving individualized therapy for SKCM patients.

Inhibition of Sema4D attenuates pressure overload-induced pathological myocardial hypertrophy via the MAPK/NF-κB/NLRP3 pathways

Sema4D (CD100) is closely related to pathological and physiological processes, including tumor growth, angiogenesis and cardiac development. Nevertheless, the role and mechanism of Sema4D in cardiac hypertrophy are still unclear to date. To assess the impact of Sema4D on pathological cardiac hypertrophy, TAC surgery was performed on C57BL/6 mice which were transfected with AAV9-mSema4D-shRNA or AAV9-mSema4D adeno-associated virus by tail vein injection. Our results indicated that Sema4D knockdown mitigated cardiac hypertrophy, fibrosis and dysfunction when exposed to pressure overload, and Sema4D downregulation markedly inhibited cardiomyocyte hypertrophy induced by angiotensin II. Meanwhile, Sema4D overexpression had the opposite effect in vitro and in vivo. Furthermore, analysis of signaling pathways showed that Sema4D activated the MAPK pathway during cardiac hypertrophy induced by pressure overload, and the pharmacological mitogen-activated protein kinase kinase 1/2 inhibitor U0126 almost completely reversed Sema4D overexpression-induced deteriorated phenotype, resulting in improved cardiac function. Further research indicated that myocardial hypertrophy induced by Sema4D was closely related to the expression of the pyroptosis-related proteins PP65, NLRP3, caspase-1, ASC, GSDMD, IL-18 and IL-1β. In conclusion, our study demonstrated that Sema4D regulated the process of pathological myocardial hypertrophy through modulating MAPK/NF-κB/NLRP3 pathway, and Sema4D may be the promising interventional target of cardiac hypertrophy and heart failure.

SEMA3G functions as a novel prognostic biomarker associated with Wnt pathway in clear cell renal cell carcinoma

Renal cell cancer (RCC) is one of the most common cancer, and the incidence of clear cell renal cell cancer rank at the first among multiple subtypes of RCC. Tumor heterogeneity and limited therapies expedite researches and studies on prognostic biomarkers and molecular mechanism. SEMA3G mediates various bimolecular processes but few studies have assessed the influence of SEMA3G on ccRCC. The expression of SEMA3G at mRNA level in ccRCC was analyzed using 4 TCGA datasets. The expression at protein level was verified by immunohistochemistry and western blot. Biological pathway was explored by GSEA and western blot. At both mRNA and protein level, SEMA3G expressed significantly lower in ccRCC tissues compared with normal renal tissues, and the expression was highly associated with clinical stage and pathological grade. Low expression of SEMA3G indicated a poorer overall survival and disease specific survival. Transwell and wound-healing assays showed that overexpressed SEMA3G inhibited the cell motility of renal cancer cells. Upregulated SEMA3G suppressed the invasion and proliferation of both 769-P and 786-O cells. Wnt signaling pathway was tested to work in the interfering of SEMA3G on tumorigenesis and progression of ccRCC. The results provide novel insight into the role of SEMA3G in ccRCC, suggesting the prognostic value and potential suppressor role of SEMA3G.

Modulation of semaphorin 3C & 4D expression in cancerous tissues from individuals with laryngeal squamous cell carcinoma

BACKGROUND OBJECTIVES

Semaphorins were initially characterized as axon guidance factors but were subsequently implicated in the regulation of immune responses, angiogenesis, organ formation and a variety of other physiological and developmental functions. Various semaphorins enhance or inhibit tumour progression through different mechanisms. The objective of this study was to assess the expression of various semaphorins and vascular endothelial growth factor (VEGF) gene transcripts as well as the serum level of Sema3A in individuals with laryngeal squamous cell carcinoma (LSCC).

METHODS

Tissue expression of Sema3A, Sema3C, Sema4D, Sema6D and VEGF was determined in both tumour tissues and tissues around the tumour from 30 individuals with pathologically confirmed LSCC using quantitative real-time PCR. Furthermore, the serum level of Sema3A in these individuals was assessed using enzyme-linked immunosorbent assay.

RESULTS

Sema3C gene transcript showed a significant increase (P=0.001), while Sema4D was observed with a significant decrease in tumour samples compared to non-tumoural tissues (P≤0.01). The expression of the Sema3C gene was found to be associated with the stage of LSCC tumour as it was statistically significant for tumours with stage IV (P<0.01). The serum level of Sema3A was not found to be significant between cases and controls.

INTERPRETATION CONCLUSIONS

Increased expression of Sema3C but decreased expression of Sema4D in tumour tissue of LSCC may introduce these two growth factors as crucial mediators orchestrating tumour growth in individuals with LSCC. This result could open a new vision for the treatment of this malignancy.

SEMA3B-AS1 suppresses colorectal carcinoma progression by inhibiting Semaphorin 3B-dependent VEGF signaling pathway activation

Mounting evidence has demonstrated the considerable regulatory effects of long noncoding RNAs (lncRNAs) in the tumorigenesis and progression of various carcinomas. LncRNA Semaphorin 3B (SEMA3B) antisense RNA 1 (SEMA3B-AS1) has been found to be dysregulated in a few carcinomas recently. However, its potential function and mechanism in colorectal carcinoma (CRC) have not yet been examined. Here we show that SEMA3B-AS1 acts as a crucial regulator of CRC progression. We found that SEMA3B-AS1 expression was downregulated in CRC cell lines and tissues. Downregulation of SEMA3B-AS1 was significantly associated with poor survival in CRC patients. Overexpression of SEMA3B-AS1 reduced the cell growth and metastasis of CRC in vivo and in vitro. In addition, SEMA3B-AS1 promoted the expression of its sense-cognate gene SEMA3B, a member of the Semaphorin family (SEMAs), by recruiting EP300 to induce H3K9 acetylation at the SEMA3B promoter. Furthermore, we proved that SEMA3B-AS1 suppressed CRC angiogenesis by affecting the vascular endothelial growth factor signaling pathway activation which was regulated by the SEMA3B-NRP1 axis. Our work unravels a novel mechanism of SEMA3B-AS1 in the inhibition of CRC malignant progression and highlights its probability as a new promising diagnostic marker and therapeutic target for CRC interventions.

Cleavage of semaphorin 4 C interferes with the neuroprotective effect of the semaphorin 4 C/Plexin B2 pathway on experimental intracerebral hemorrhage in rats

Semaphorin 4 C (SEMA4C) and its cognate receptor Plexin B2 are important regulators of axon guidance and are involved in many neurological diseases, in which SEMA4C acts not only as a ligand ("forward" mode) but also as a signaling receptor ("reverse" mode). However, the role of SEMA4C/Plexin B2 in intracerebral hemorrhage (ICH) remains unclear. In this study, ICH in adult male Sprague-Dawley rats was induced by autologous blood injection in the right basal ganglia. In vitro, cultured primary neurons were subjected to OxyHb to imitate ICH injury. Recombinant SEMA4C (rSEMA4C) and overexpressing lentiviruses encoding full-length SEMA4C or secretory SEMA4C (sSEMA4C) were administered to rats by intraventricular injection. First, we found that elevated levels of sSEMA4C in the cerebrospinal fluid (CSF) of clinical patients were associated with poor prognosis. Both SEMA4C and sSEMA4C were increased in brain tissue around the hematoma after ICH in rats. Overexpression of SEMA4C attenuated neuronal apoptosis, neurosis, and neurologic impairment after ICH. However, treatment with rSEMA4C or sSEMA4C overexpression exacerbated neuronal injury. In addition, when treated with SEMA4C overexpression, the forward mode downstream protein RhoA and the reverse mode downstream ID1/3 transcriptional factors of SEMA4C/Plexin B2 signaling were all activated. Nevertheless, when exposed to rSEMA4C or sSEMA4C overexpression, only the forward mode was activated. Thus, sSEMA4C may be a novel molecular biomarker to predict the prognosis of patients with ICH, and the prevention of SEMA4C cleavage is expected to be a promising therapeutic target.

Emerging roles and mechanisms of semaphorins activity in cancer

Semaphorins are regulatory molecules that are linked to the modulation of several cancer processes, such as angiogenesis, cancer cell invasiveness and metastasis, tumor growth, as well as cancer cell survival. Semaphorin (SEMA) activity depends on the cancer histotypes and their particularities. In broad terms, the effects of SEMAs result from their interaction with specific receptors/co-receptors - Plexins, Neuropilins and Integrins - and the subsequent effects upon the downstream effectors (e.g. PI3K/AKT, MAPK/ERK). The present article serves as an integrative review work, discussing the broad implications of semaphorins in cancer, focusing on cell proliferation/survival, angiogenesis, invasion, metastasis, stemness, and chemo-resistance/response whilst highlighting their heterogeneity as a family. Herein, we emphasized that semaphorins are largely implicated in cancer progression, interacting with the tumor microenvironment components. Whilst some SEMAs (e.g. SEMA3A, SEMA3B) function widely as tumor suppressors, others (e.g. SEMA3C) act as pro-tumor semaphorins. The differences observed in terms of the biological structure of SEMAs and the particularities of each cancer histotypes require that each semaphorin be viewed as a unique entity, and its roles must be researched accordingly. A more in-depth and comprehensive view of the molecular mechanisms that promote and sustain the malignant behavior of cancer cells is of utmost importance.

Comparative transcriptomic analysis and genome-wide characterization of the Semaphorin family reveal the potential mechanism of angiogenesis around embryo in ovoviviparous black rockfish (Sebastes schlegelii)

To guarantee the quality and survival rate of their offspring, ovoviviparous teleost evolved special characteristics of in vivo fertilization and embryo development. Maternal black rockfish, having over 50 thousand embryos developing within the ovary simultaneously, provided around 40% nutrition throughout oocyte development, while the capillaries around each embryo contributed the rest 60% during pregnancy. Since fertilization, capillaries started to proliferate and developed into a placenta-like structure that covered over half of each embryo. Aimed to characterize the potential mechanism behind, comparative transcriptome analysis of samples collected according to the process of pregnancy. Three important time point in the process, including mature oocyte stage, fertilization and sarcomere period, were chosen for the transcriptome sequencing. Our study identified key pathways and genes involved in the cell cycle as well as DNA replication and repair, cell migration and adhesion, immune, and metabolic functions. Notably, several of the semaphoring gene family members were differently expressed. To confirm the accuracy of these genes, total of 32 sema genes were identified from the whole genome and distinct expression pattern of sema genes was observed in different pregnant stages. Our results revealed a novel insight for further investigating the functions of sema genes in reproduction physiology and embryo processes in ovoviviparous teleost.

Mutated axon guidance gene PLXNB2 sustains growth and invasiveness of stem cells isolated from cancers of unknown primary

The genetic changes sustaining the development of cancers of unknown primary (CUP) remain elusive. The whole-exome genomic profiling of 14 rigorously selected CUP samples did not reveal specific recurring mutation in known driver genes. However, by comparing the mutational landscape of CUPs with that of most other human tumor types, it emerged a consistent enrichment of changes in genes belonging to the axon guidance KEGG pathway. In particular, G842C mutation of PlexinB2 (PlxnB2) was predicted to be activating. Indeed, knocking down the mutated, but not the wild-type, PlxnB2 in CUP stem cells resulted in the impairment of self-renewal and proliferation in culture, as well as tumorigenic capacity in mice. Conversely, the genetic transfer of G842C-PlxnB2 was sufficient to promote CUP stem cell proliferation and tumorigenesis in mice. Notably, G842C-PlxnB2 expression in CUP cells was associated with basal EGFR phosphorylation, and EGFR blockade impaired the viability of CUP cells reliant on the mutated receptor. Moreover, the mutated PlxnB2 elicited CUP cell invasiveness, blocked by EGFR inhibitor treatment. In sum, we found that a novel activating mutation of the axon guidance gene PLXNB2 sustains proliferative autonomy and confers invasive properties to stem cells isolated from cancers of unknown primary, in EGFR-dependent manner.

Ophthalmic Solution of Smart Supramolecular Peptides to Capture Semaphorin 4D against Diabetic Retinopathy

Diabetic retinopathy (DR) is the leading cause of vision loss in working age population. Intravitreal injection of anti-VEGF antibody is widely used in clinical practice. However, about 27% of patients show poor response to anti-VEGF therapy and about 50% of these patients continue to have macular thickening. Frequent intravitreal injections of antibody may increase the chance of endophthalmitis and cause visual loss or even blindness once happened. Therefore, there is a greatly urgent need for novel noninvasive target to treat DR clinically. Here, the formulation of a smart supramolecular peptide (SSP) eye drop for DR treatment that is effective via specifically identifying and capturing soluble semaphorin 4D (sSema4D), a strongly pro-angiogenesis and exudates factor, is reported. The SSP nanostructures encapsulate sSema4D so that all biological effects mediated by three receptors of sSema4D are inhibited, thereby significantly alleviating pathological retinal angiogenesis and exudates in DR. Moreover, it is found that combination of SSPs eye drop and anti-VEGF injection shows better therapeutic effect over anti-VEGF treatment alone. Overall, SSP eye drop provide an alternative and effective method for noninvasive treatment for DR.

Adaptive activation of EFNB2/EPHB4 axis promotes post-metastatic growth of colorectal cancer liver metastases by LDLR-mediated cholesterol uptake

The microenvironment of distant organ plays vital roles in regulating tumor metastases. However, little is known about the crosstalk between metastasized tumor cells and target organs. Herein, we found that EFNB2 expression was upregulated in liver metastases (LM) of colorectal cancer (CRC), but not in pulmonary metastases (PM) or primary CRC tumors. EFNB2 played a tumor-promoting role in CRC LM in vitro and in vivo. Through forward signaling, EFNB2-promoted CRC LM by interacting with the EPHB4 receptor. EFNB2/EPHB4 axis enhances LDLR-mediated cholesterol uptake in CRC LM. Subsequently, EFNB2/EPHB4 axis promotes LDLR transcription by regulating STAT3 phosphorylation. Blocking LDLR reversed the role of the EFNB2/EPHB4 axis in promoting CRC LM. Using clinical data, survival analysis revealed that the survival time of patients with CRC LM was decreased in patients with high EFNB2 expression, compared with low EFNB2 expression. Inhibition of the EFNB2/EPHB4 axis markedly prolonged the survival time of BALB/c nude mice with CRC LM with a high cholesterol diet. These findings revealed a key step in the regulation of cholesterol uptake by EFNB2/EPHB4 axis and its tumor-promoting role in CRC LM.

Identification of Key Genes Associated with Risk and Prognosis of Neuroblastoma

Neuroblastoma is a childhood malignancy with high morbidity and mortality. We identified key biomarkers associated with neuroblastoma risk and prognosis. The gene modules most associated with neuroblastoma risk were derived by WGCNA. Modular genes were intersected with differentially expressed genes between patients with high-risk (HR) and non-high-risk (NHR) to obtain risk genes, and enrichment analysis was performed. After incorporating risk genes into Cox regression analysis, LASSO algorithm, and K-M survival analysis, key genes were identified and introduced into four external datasets for validation. We performed short time-series expression miner analysis and single-sample genome enrichment analysis. Finally, we evaluated the difference in DNA methylation levels to identify meaningful methylation marks. We identified 5 key genes (ANO6, CPNE2, DST, PLXNC1, SCN3A) for neuroblastoma risk and prognosis, which correlated closely with known neuroblastoma biomarkers. All key genes showed a progressive downregulation trend with increasing risk levels of neuroblastoma. The immune infiltration of 14 immune cells was significantly different between HR-NB and NHR-NB, and most immune cells were negatively correlated with key genes. Furthermore, the expression of ANO6, CPNE2, DST, and PLXNC1 was modified by DNA methylation. This study identified 5 key genes for neuroblastoma risk and prognosis that were potential biomarkers.

Neurovascular coupling in bone regeneration

The mammalian skeletal system is densely innervated by both neural and vascular networks. Peripheral nerves in the skeleton include sensory and sympathetic nerves. The crosstalk between skeletal and neural tissues is critical for skeletal development and regeneration. The cellular processes of osteogenesis and angiogenesis are coupled in both physiological and pathophysiological contexts. The cellular and molecular regulation of osteogenesis and angiogenesis have yet to be fully defined. This review will provide a detailed characterization of the regulatory role of nerves and blood vessels during bone regeneration. Furthermore, given the importance of the spatial relationship between nerves and blood vessels in bone, we discuss neurovascular coupling during physiological and pathological bone formation. A better understanding of the interactions between nerves and blood vessels will inform future novel therapeutic neural and vascular targeting for clinical bone repair and regeneration.

The role of semaphorins in cardiovascular diseases: Potential therapeutic targets and novel biomarkers

Semaphorins (Semas), which belongs to the axonal guidance molecules, include 8 classes and could affect axon growth in the nervous system. Recently, semaphorins were found to regulate other pathophysiological processes, such as immune response, oncogenesis, tumor angiogenesis, and bone homeostasis, through binding with their plexin and neuropilin receptors. In this review, we summarized the detailed role of semaphorins and their receptors in the pathological progression of various cardiovascular diseases (CVDs), highlighting that semaphorins may be potential therapeutic targets and novel biomarkers for CVDs.

miR-181b targets semaphorin 3A to mediate TGF-β-induced endothelial-mesenchymal transition related to atrial fibrillation

Atrial fibrosis is an essential contributor to atrial fibrillation (AF). It remains unclear whether atrial endocardial endothelial cells (AEECs) that undergo endothelial-mesenchymal transition (EndMT) are among the sources of atrial fibroblasts. We studied human atria, TGF-β-treated human AEECs, cardiac-specific TGF-β-transgenic mice, and heart failure rabbits to identify the underlying mechanism of EndMT in atrial fibrosis. Using isolated AEECs, we found that miR-181b was induced in TGF-β-treated AEECs, which decreased semaphorin 3A (Sema3A) and increased EndMT markers, and these effects could be reversed by a miR-181b antagomir. Experiments in which Sema3A was increased by a peptide or decreased by a siRNA in AEECs revealed a mechanistic link between Sema3A and LIM-kinase 1/phosphorylated cofilin (LIMK/p-cofilin) signaling and suggested that Sema3A is upstream of LIMK in regulating actin remodeling through p-cofilin. Administration of the miR-181b antagomir or recombinant Sema3A to TGF-β-transgenic mice evoked increased Sema3A, reduced EndMT markers, and significantly decreased atrial fibrosis and AF vulnerability. Our study provides a mechanistic link between the induction of EndMT by TGF-β via miR-181b/Sema3A/LIMK/p-cofilin signaling to atrial fibrosis. Blocking miR-181b and increasing Sema3A are potential strategies for AF therapeutic intervention.

Application of two-dimensional difference gel electrophoresis to identify protein changes between center, margin, and adjacent non-tumor tissues obtained from non-small-cell lung cancer with adenocarcinoma or squamous cell carcinoma subtype

Lung cancer is responsible for the most cancer-related mortality worldwide and the mechanism of its development is poorly understood. Proteomics has become a powerful tool offering vital knowledge related to cancer development. Using a two-dimensional difference gel electrophoresis (2D-DIGE) approach, we sought to compare tissue samples from non-small-cell lung cancer (NSCLC) patients taken from the tumor center and tumor margin. Two subtypes of NSCLC, adenocarcinoma (ADC) and squamous cell carcinoma (SCC) were compared. Data are available via ProteomeXchange with identifier PXD032736 and PXD032962 for ADC and SCC, respectively. For ADC proteins, 26 significant canonical pathways were identified, including Rho signaling pathways, a semaphorin neuronal repulsive signaling pathway, and epithelial adherens junction signaling. For SCC proteins, nine significant canonical pathways were identified, including hypoxia-inducible factor-1α signaling, thyroid hormone biosynthesis, and phagosome maturation. Proteins differentiating the tumor center and tumor margin were linked to cancer invasion and progression, including cell migration, adhesion and invasion, cytoskeletal structure, protein folding, anaerobic metabolism, tumor angiogenesis, EMC transition, epithelial adherens junctions, and inflammatory responses. In conclusion, we identified several proteins that are important for the better characterization of tumor development and molecular specificity of both lung cancer subtypes. We also identified proteins that may be important as biomarkers and/or targets for anticancer therapy.

Semaphorins as Potential Immune Therapeutic Targets for Cancer

Semaphorins are a large class of secreted or membrane-bound molecules. It has been reported that semaphorins play important roles in regulating several hallmarks of cancer, including angiogenesis, metastasis, and immune evasion. Semaphorins and their receptors are widely expressed on tumor cells and immune cells. However, the biological role of semaphorins in tumor immune microenvironment is intricate. The dysregulation of semaphorins influences the recruitment and infiltration of immune cells, leading to abnormal anti-tumor effect. Although the underlying mechanisms of semaphorins on regulating tumor-infiltrating immune cell activation and functions are not fully understood, semaphorins can notably be promising immunotherapy targets for cancer.

TSP1 is the essential domain of SEMA5A involved in pannus formation in rheumatoid arthritis

OBJECTIVE

In this study, we explored the effect of semaphorin5A (SEMA5A) on RA pathogenesis and its specific TSP1 domain on pannus formation.

METHODS

The expression of SEMA5A was detected in the synovium, the fibroblast-like synoviocytes (FLSs) and the SF of RA patients and healthy controls (HCs) by real-time quantitative PCR (q-PCR), immunohistochemistry staining, western blot and ELISA. SEMA5A-mAb intervention was performed to appraise the severity of joints in the CIA model. Transcriptome sequencing and bioinformatics analysis in SEMA5A-transfected FLSs from HCs were performed to screen differentially expressed genes after SEMA5A overexpression. An MTT assay in RA-FLSs, a chicken embryo allantoic membrane experiment and a tube formation experiment were used to clarify the influence of SEMA5A on cell proliferation and angiogenesis. Furthermore, a rescue experiment verified the function of the TSP1 domain of SEMA5A in the progress of RA with Sema5a-/- CIA mice.

RESULTS

The expression of SEMA5A increased in RA compared with that in HCs. Simultaneously, SEMA5A-mAbs significantly attenuated joint injury and the inflammatory response in CIA models. In addition, transcriptome sequencing and angiogenesis-related experiments verified the ability of SEMA5A to promote FLS proliferation and angiogenesis. Moreover, TSP1 was proved to be an essential domain in SEMA5A-induced angiogenesis in vitro. Additionally, rescue of TSP1-deleted SEMA5A failed to reduce the severity of arthritis in a CIA model constructed with Sema5a -/- mice.

CONCLUSION

In summary, upregulation of SEMA5A was first confirmed in pathological lesions of RA patients. Furthermore, treatment with SEMA5A-mAbs attenuated the progress of RA in the CIA model. Moreover, TSP1 was indicated as the key domain of SEMA5A in the promotion of pannus formation in RA.

Advances in antigens associated with Idiopathic Membranous Nephropathy

Membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults. Idiopathic MN (IMN), one of the forms of MN, usually has an unknown etiology. IMN is described as an autoimmune disease, and its pathogenesis is quite complex. The discovery of the M-type phospholipase A₂ receptor (PLA₂R) plays an important role in promoting our understanding of IMN, although the exact mechanisms of its occurrence and development are still not completely clear. Other target antigens have been discovered one after another, as considerable progress has been made in the molecular pathomechanisms of IMN. Here, we review the findings about the target antigens associated with IMN in recent years. It is hoped that this article can provide researchers with some scientific issues or innovative ideas for future studies of IMN, which will provide clinicians with more knowledge about further improving their abilities to provide better medical care for IMN patients.

Roles and Mechanisms of Axon-Guidance Molecules in Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disease that is characterized by progressive memory decline and cognitive dysfunctions. Although the causes of AD have not yet been established, many mechanisms have been proposed. Axon-guidance molecules play the roles in the occurrence and development of AD by participating in different mechanisms. Therefore, what roles do axon-guidance molecules play in AD? This study aimed at elucidating how axon-guidance molecules Netrins, Slits, Semaphorins, and Ephrins regulate the levels of Aβ, hyperphosphorylation of tau protein, Reelin, and other ways through different signaling pathways, in order to show the roles of axon-guidance molecules in the occurrence and development of AD. And it is hoped that this study can provide a theoretical basis and new perspectives in the search for new therapeutic targets for AD.

Sema3C promotes hepatic metastasis and predicts poor prognosis in gastric adenocarcinoma

OBJECTIVE

Semaphorin 3C (Sema3C) may regulate tumor metastasis and prognosis. We determined the biological roles of Sema3C in the hepatic metastasis of gastric adenocarcinoma and evaluated its clinical significance as a potential biomarker.

METHODS

Sema3C expression in gastric cancer (GC) cell lines and tissues was measured using RT-qPCR and western blotting. Moreover, Sema3C functions were analyzed using Transwell assays and in vitro metastasis assays in gain- and loss-of-function experiments. Furthermore, the impact of Sema3C on the prognosis of 80 randomly selected patients with GC was investigated by immunohistochemistry. Additionally, the expression of epithelial-mesenchymal transition (EMT) indicators was verified by immunohistochemistry in GC tissues.

RESULTS

Sema3C expression was significantly upregulated in highly metastatic GC cell lines and tissues. Additionally, Sema3C promoted invasion, migration and hepatic metastasis in GC cells. Moreover, Sema3C expression was positively correlated with clinicopathological features in GC and paired hepatic metastatic tissues, and Sema3C expression was an independent prognostic factor. Finally, Sema3C expression was associated with node metastasis, hepatic metastasis and EMT marker expression.

CONCLUSIONS

Sema3C may play roles in regulating the EMT and metastasis of gastric adenocarcinoma, highlighting its potential use as a prognostic factor for hepatic metastasis and poor prognosis in gastric adenocarcinoma.

The role of immune semaphorins in the pathogenesis of multiple sclerosis: Potential therapeutic targets

The immune and nervous systems possess a highly intricate network of synaptic connections, shared messenger molecules, and exquisite communication ways, allowing intercellular signal transduction. The semaphorins (Semas) were initially identified as axonal guidance molecules in the development of the nervous system but later were found to be implicated also in regulating the immune system, known in this case as the "immune Semas" or "immunoregulatory Semas". Increasingly, these molecules are involved in multiple aspects of both physiological and pathological immune responses and were recently indicated to take part in various immunological disorders, encompassing allergy, cancer, and autoimmunity. Semas transduce signals by connecting to their cognate receptors, namely, plexins and neuropilins. Some of them, like Sema-3F, have been found to function as the inducer of the remyelination process whereas some others, like Sema-3A and Sema-4D, act to inhibit this process, either directly or indirectly. Besides, Sema-4A is crucial to the differentiation of T helper type 1 (Th1) and Th17 cells that are potentially involved in the pathogenesis of multiple sclerosis (MS), an autoimmune disease of the central nervous system. This review aims to reveal the role of immune Semas in the pathogenesis of MS and its animal model, experimental autoimmune encephalomyelitis, focusing on the therapeutic usages of these molecules to treat this neurodegenerative disease.

Tumor microenvironment in head and neck squamous cell carcinoma: Functions and regulatory mechanisms

The tumor microenvironment has been recently reported to play a pivotal role in sustaining tumor cells survival and protecting them from immunotherapy and chemotherapy-induced death. It remains largely unknown how the specific signaling pathway exerts the tumor microenvironment in head and neck squamous cell carcinoma though previous studies have elucidated the regulatory mechanisms involve in tumor immune microenvironment, stromal cells, tumor angiogenesis and cancer stem cell. These components are responsible for tumor progression as well as anti-cancer therapy resistance, leading to rapid tumor growth and treatment failure. In this review, we focus on discussing the interaction between tumor cells and the surrounding components for better understanding of anti-cancer treatment ineffectiveness and its underlying molecular mechanisms.

Mechanochemical control of epidermal stem cell divisions by B-plexins

The precise spatiotemporal control of cell proliferation is key to the morphogenesis of epithelial tissues. Epithelial cell divisions lead to tissue crowding and local changes in force distribution, which in turn suppress the rate of cell divisions. However, the molecular mechanisms underlying this mechanical feedback are largely unclear. Here, we identify a critical requirement of B-plexin transmembrane receptors in the response to crowding-induced mechanical forces during embryonic skin development. Epidermal stem cells lacking B-plexins fail to sense mechanical compression, resulting in disinhibition of the transcriptional coactivator YAP, hyperproliferation, and tissue overgrowth. Mechanistically, we show that B-plexins mediate mechanoresponses to crowding through stabilization of adhesive cell junctions and lowering of cortical stiffness. Finally, we provide evidence that the B-plexin-dependent mechanochemical feedback is also pathophysiologically relevant to limit tumor growth in basal cell carcinoma, the most common type of skin cancer. Our data define a central role of B-plexins in mechanosensation to couple cell density and cell division in development and disease.

Class-3 semaphorins: Potent multifunctional modulators for angiogenesis-associated diseases

Semaphorins, the neuronal guidance cues, were shown to have broad influences on pathophysiological processes such as bone remodeling, immune responses, and angiogenesis. In particular, Class-3 Semaphorins (SEMA3) is considered a vital regulator involved in angiogenesis. Scientific evidence has pointed to the role of angiogenesis in many diseases, and numerous efforts have been made to explore the possibilities of curing those diseases by targeting angiogenesis. Nevertheless, the efficacies are limited owing to the complex mechanisms of angiogenesis. Hence, investigating the mechanisms of SEMA3 in angiogenesis may contribute to novel therapeutics for diseases. Previous reviews mainly focused on the various functions of semaphorins in one particular disease, and the specific angiogenesis mechanism of SEMA3 in diverse diseases has not been well elucidated. Additionally, the role of SEMA3 in angiogenesis remains elusive, as contradicting results have been found in different disease types. Some evidence from recent studies implies that, while most SEMA3 molecules inhibit pathological angiogenesis in different diseases, occasionally SEMA3 may also promote angiogenesis. This review summarizes the specific role of SEMA3 in a variety of angiogenesis-associated diseases, and documents SEMA3 may be a promising therapeutic target for treating angiogenesis-associated diseases.

Mesenchymal Stromal Cells Promote Retinal Vascular Repair by Modulating Sema3E and IL-17A in a Model of Ischemic Retinopathy

Ischemic retinopathies (IRs), such as retinopathy of prematurity and diabetic retinopathy, are characterized by an initial phase of microvascular degeneration that results in retinal ischemia, followed by exaggerated pathologic neovascularization (NV). Mesenchymal stromal cells (MSCs) have potent pro-angiogenic and anti-inflammatory properties associated with tissue repair and regeneration, and in this regard exert protection to neurons in ischemic and degenerative conditions; however, the exact mechanisms underlying these functions remain largely unknown. Class III Semaphorins (A–G) are particularly implicated in regulating neural blood supply (as well as neurogenesis) by suppressing angiogenesis and affecting myeloid cell function; this is the case for distinct neuropillin-activating Sema3A as well as PlexinD1-activating Sema3E; but during IR the former Sema3A increases while Sema3E decreases. We investigated whether retinal vascular repair actions of MSCs are exerted by normalizing Semaphorin and downstream cytokines in IR. Intravitreal administration of MSCs or their secretome (MSCs-conditioned media [MSCs-CM]) significantly curtailed vasoobliteration as well as aberrant preretinal NV in a model of oxygen-induced retinopathy (OIR). The vascular repair effects of MSCs-CM in the ischemic retina were associated with restored levels of Sema3E. Vascular benefits of MSCs-CM were reversed by anti-Sema3E; while intravitreal injection of anti-angiogenic recombinant Sema3E (rSema3E) in OIR-subjected mice reproduced effects of MSCs-CM by inhibiting as expected preretinal NV but also by decreasing vasoobliteration. To explain these opposing vascular effects of Sema3E we found in OIR high retinal levels, respectively, of the pro- and anti-angiogenic IL-17A and Sema3A-regulating IL-1β; IL-17A positively affected expression of IL-1β. rSema3E decreased concentrations of these myeloid cell-derived pro-inflammatory cytokines in vitro and in vivo. Importantly, IL-17A suppression by MSCs-CM was abrogated by anti-Sema3E neutralizing antibody. Collectively, our findings provide novel evidence by which MSCs inhibit aberrant NV and diminish vasoobliteration (promoting revascularization) in retinopathy by restoring (at least in part) neuronal Sema3E levels that reduce pathological levels of IL-17A (and in turn other proinflammatory factors) in myeloid cells. The ability of MSCs to generate a microenvironment permissive for vascular regeneration by controlling the production of neuronal factors involved in immunomodulatory activities is a promising opportunity for stem cell therapy in ocular degenerative diseases.

Semaphorins as emerging clinical biomarkers and therapeutic targets in cancer

Semaphorins are a large family of developmental regulatory signals, characterized by aberrant expression in human cancers. These molecules crucially control cell-cell communication, cell migration, invasion and metastasis, tumor angiogenesis, inflammatory and anti-cancer immune responses. Semaphorins comprise secreted and cell surface-exposed molecules and their receptors are mainly found in the Plexin and Neuropilin families, which are further implicated in a signaling network controlling the tumor microenvironment. Accumulating evidence indicates that semaphorins may be considered as novel clinical biomarkers for cancer, especially for the prediction of patient survival and responsiveness to therapy. Moreover, preclinical experimental studies have demonstrated that targeting semaphorin signaling can interfere with tumor growth and/or metastatic dissemination, suggesting their relevance as novel therapeutic targets in cancer; this has also prompted the development of semaphorin-interfering molecules for application in the clinic. Here we will survey, in diverse human cancers, the current knowledge about the relevance of semaphorin family members, and conceptualize potential lines of future research development in this field.

The Role of Semaphorins in Metabolic Disorders

Semaphorins are a family originally identified as axonal guidance molecules. They are also involved in tumor growth, angiogenesis, immune regulation, as well as other biological and pathological processes. Recent studies have shown that semaphorins play a role in metabolic diseases including obesity, adipose inflammation, and diabetic complications, including diabetic retinopathy, diabetic nephropathy, diabetic neuropathy, diabetic wound healing, and diabetic osteoporosis. Evidence provides mechanistic insights regarding the role of semaphorins in metabolic diseases by regulating adipogenesis, hypothalamic melanocortin circuit, immune responses, and angiogenesis. In this review, we summarize recent progress regarding the role of semaphorins in obesity, adipose inflammation, and diabetic complications.

Characterization of Class-3 Semaphorin Receptors, Neuropilins and Plexins, as Therapeutic Targets in a Pan-Cancer Study

Class-3 semaphorins (SEMA3s), initially characterized as axon guidance cues, have been recognized as key regulators for immune responses, angiogenesis, tumorigenesis and drug responses. The functions of SEMA3s are attributed to the activation of downstream signaling cascades mainly mediated by cell surface receptors neuropilins (NRPs) and plexins (PLXNs), yet their roles in human cancers are not completely understood. Here, we provided a detailed pan-cancer analysis of NRPs and PLXNs in their expression, and association with key signal transducers, patient survival, tumor microenvironment (TME), and drug responses. The expression of NRPs and PLXNs were dysregulated in many cancer types, and the majority of them were further dysregulated in metastatic tumors, indicating a role in metastatic progression. Importantly, the expression of these genes was frequently associated with key transducers, patient survival, TME, and drug responses; however, the direction of the association varied for the particular gene queried and the specific cancer type/subtype tested. Specifically, NRP1, NRP2, PLXNA1, PLXNA3, PLXNB3, PLXNC1, and PLXND1 were primarily associated with aggressive phenotypes, whereas the rest were more associated with favorable prognosis. These data highlighted the need to study each as a separate entity in a cancer type- and subtype-dependent manner.

The role of semaphorins in small vessels of the eye and brain

Small vessel diseases, such as ischemic retinopathy and cerebral small vessel disease (CSVD), are increasingly recognized in patients with diabetes, dementia and cerebrovascular disease. The mechanisms of small vessel diseases are poorly understood, but the latest studies suggest a role for semaphorins. Initially identified as axon guidance cues, semaphorins are mainly studied in neuronal morphogenesis, neural circuit assembly, and synapse assembly and refinement. In recent years, semaphorins have been found to play important roles in regulating vascular growth and development and in many pathophysiological processes, including atherosclerosis, angiogenesis after stroke and retinopathy. Growing evidence indicates that semaphorins affect the occurrence, perfusion and regression of both the macrovasculature and microvasculature by regulating the proliferation, apoptosis, migration, barrier function and inflammatory response of endothelial cells, vascular smooth muscle cells (VSMCs) and pericytes. In this review, we concentrate on the regulatory effects of semaphorins on the cell components of the vessel wall and their potential roles in microvascular diseases, especially in the retina and cerebral small vessel. Finally, we discuss potential molecular approaches in targeting semaphorins as therapies for microvascular disorders in the eye and brain.

Semaphorin 3B-associated membranous nephropathy is a distinct type of disease predominantly present in pediatric patients

Membranous nephropathy results from subepithelial antigen-antibody complex deposition along the glomerular basement membrane. Although PLA2R, THSD7A, and NELL-1 account for a majority (about 80%) of the target antigens, the target antigen in the remaining cases is not known. Using laser microdissection of PLA2R-negative glomeruli of patients with membranous nephropathy followed by mass spectrometry we identified a unique protein, Semaphorin 3B, in three cases. Mass spectrometry failed to detect Semaphorin-3B in 23 PLA2R-associated cases of membranous nephropathy and 88 controls. Semaphorin 3B in all three cases was localized to granular deposits along the glomerular basement membrane by immunohistochemistry. Next, an additional eight cases of Semaphorin 3B-associated membranous nephropathy were identified in three validation cohorts by immunofluorescence microscopy. In four of 11 cases, kidney biopsy also showed tubular basement membrane deposits of IgG on frozen sections. Confocal microscopy showed that both IgG and Semaphorin 3B co-localized to the glomerular basement membrane. Western blot analysis of five available sera showed reactivity to reduced Semaphorin 3B in four of four patients with active disease and no reactivity in one patient in clinical remission; there was also no reactivity in control sera. Eight of the 11 cases of Semaphorin 3B-associated membranous nephropathy were pediatric cases. Furthermore, in five cases, the disease started at or below the age of two. Thus, Semaphorin 3B-associated membranous nephropathy appears to be a distinct type of disease; more likely to be present in pediatric patients.

Immune semaphorins: Crucial regulatory signals and novel therapeutic targets in asthma and allergic diseases

Asthma and allergic diseases are a group of chronic inflammatory disorders that arise as a result of excessive responses of the immune system against intrinsically harmless environmental substances. It is well known that substantial joint characteristics exist between the immune and nervous systems. The semaphorins (Semas) were initially characterized as axon-guidance molecules that play a crucial role during the development of the nervous system. However, increasing evidence indicates that a subset of Semas, termed "immune Semas", acting through their cognate receptors, namely, plexins (Plxns), and neuropilins (Nrps), also contributes to both physiological and pathological responses of the immune system. Notably, immune Semas exert critical roles in regulating a broad spectrum of biological processes, including immune cell-cell interactions, activation, differentiation, cell migration and mobility, angiogenesis, tumor progression, as well as inflammatory responses. Accumulating evidence indicates that the modification in the signaling of immune Semas could lead to various immune-mediated inflammatory diseases, ranging from cancer to autoimmunity and allergies. This review summarizes the recent evidence regarding the role of immune Semas in the pathogenesis of asthma and allergic diseases and discusses their therapeutic potential for treating these diseases.

Transmembrane Peptides as Inhibitors of Protein-Protein Interactions: An Efficient Strategy to Target Cancer Cells?

Cellular functions are regulated by extracellular signals such as hormones, neurotransmitters, matrix ligands, and other chemical or physical stimuli. Ligand binding on its transmembrane receptor induced cell signaling and the recruitment of several interacting partners to the plasma membrane. Nowadays, it is well-established that the transmembrane domain is not only an anchor of these receptors to the membrane, but it also plays a key role in receptor dimerization and activation. Indeed, interactions between transmembrane helices are associated with specific biological activity of the proteins as cell migration, proliferation, or differentiation. Overexpression or constitutive dimerization (due notably to mutations) of these transmembrane receptors are involved in several physiopathological contexts as cancers. The transmembrane domain of tyrosine kinase receptors as ErbB family proteins (implicated in several cancers as HER2 in breast cancer) or other receptors as Neuropilins has been described these last years as a target to inhibit their dimerization/activation using several strategies. In this review, we will focus on the strategy which consists in using peptides to disturb in a specific manner the interactions between transmembrane domains and the signaling pathways (induced by ligand binding) of these receptors involved in cancer. This approach can be extended to inhibit other transmembrane protein dimerization as neuraminidase-1 (the catalytic subunit of elastin receptor complex), Discoidin Domain Receptor 1 (a tyrosine kinase receptor activated by type I collagen) or G-protein coupled receptors (GPCRs) which are involved in cancer processes.

A pan-cancer study of class-3 semaphorins as therapeutic targets in cancer

BACKGROUND

Initially characterized as axon guidance factors, semaphorins also have been implicated to have critical roles in multiple physiological and developmental functions, including the regulation of immune responses, angiogenesis, organ formation, and the etiology of multiple forms of cancer. Moreover, their contribution in immunity and the regulation of tumour microenvironment is becoming increasingly recognized. Here, we provide a comprehensive analysis of class-3 semaphorins, the only secreted family of genes among veterbrate semaphorins, in terms of their expression profiles and their association with patient survival. We also relate their role with immune subtypes, tumour microenvironment, and drug sensitivity using a pan-cancer study.

RESULTS

Expression profiles of class-3 semaphorins (SEMA3s) and their association with patient survival and tumour microenvironment were studied in 31 cancer types using the TCGA pan-cancer data. The expression of SEMA3 family varies in different cancer types with striking inter- and intra- cancer heterogeneity. In general, our results show that SEMA3A, SEMA3C, and SEMA3F are primarily upregulated in cancer cells, while the rest of SEMA3s are mainly down-regulated in the tested tumours. The expression of SEMA3 family members was frequently associated with patient overall survival. However, the direction of the association varied with regards to the particular SEMA3 isoform queried and the specific cancer type tested. More specifically, SEMA3A and SEMA3E primarily associate with a poor prognosis of survival, while SEMA3G typically associates with survival advantage. The rest of SEMA3s show either survival advantage or disadvantage dependent on cancer type. In addition, all SEMA3 genes show significant association with immune infiltrate subtypes, and they also correlate with level of stromal cell infiltration and tumour cell stemness with various degrees. Finally, our study revealed that SEMA3 genes, especially SEMA3C and SEMA3F may contribute to drug induced cancer cell resistance.

CONCLUSIONS

Our systematic analysis of class-3 semaphorin gene expression and their association with immune infiltrates, tumour microenvironment and cancer patient outcomes highlights the need to study each SEMA3 member as a separate entity within each specific cancer type. Also our study validated the identification of class-3 semaphorin signals as promising therapeutic targets in cancer although further laboratory validation still needed.

Semaphorin-4C is upregulated in epithelial ovarian cancer

The present retrospective study aimed to investigate the expression of semaphorin-4C (Sema4C) in epithelial ovarian cancer (EOC), and to determine the association between Sema4C expression and patient clinicopathological characteristics. Sema4C mRNA expression was detected by reverse transcription-quantitative polymerase chain reaction in the tissues of 74 cases of EOC, 20 cases of ovarian epithelial benign tumor, 20 cases of ovarian borderline epithelial tumor and 15 cases of normal ovarian tissue. Immunohistochemistry was used to detect the expression and localization of Sema4C. The association between Sema4C expression level and patients clinicopathological characteristics was determined by χ² test. The results demonstrated that Sema4C expression level in ovarian epithelial carcinoma tissues was significantly higher compared with that in benign tumors, borderline epithelial tumors and normal ovarian tissues (P<0.05). In addition, Sema4C expression in ovarian cancer tissues was significantly associated with the clinical and pathological stages of tumors (P<0.05). In conclusion, the present study demonstrated that Sema4C expression was upregulated in EOC.

Distinct pathways associated with chromosomal aberration frequency in a cohort exposed to genotoxic compounds compared to general population

Non-specific structural chromosomal aberrations (CAs) observed in peripheral blood lymphocytes of healthy individuals can be either chromosome-type aberrations (CSAs) or chromatid-type aberrations (CTAs) depending on the stage of cell division they are induced in and mechanism of formation. It is important to study the genetic basis of chromosomal instability as it is a marker of genotoxic exposure and a predictor of cancer risk. For that purpose, we conducted two genome-wide association studies (GWASs) on healthy individuals in the presence and absence of apparent genotoxic exposure from the Czech Republic and Slovakia. The pre-GWAS cytogenetic analysis reported the frequencies of CSA, CTA and total CA (CAtot). We performed both linear and binary logistic regression analysis with an arbitrary cut-off point of 2% for CAtot and 1% for CSA and CTA. Using the statistical threshold of 1.0 × 10-5, we identified five loci with in silico predicted functionality in the reference group and four loci in the exposed group, with no overlap between the associated regions. A meta-analysis on the two GWASs identified further four loci with moderate associations in each of the studies. From the reference group mainly loci within genes related to DNA damage response/repair were identified. Other loci identified from both the reference and exposed groups were found to be involved in the segregation of chromosomes and chromatin modification. Some of the discovered regions in each group were implicated in tumourigenesis and autism.

Comparing MicroRNA Profilings of Purified HER-2-Negative and HER-2-Positive Cells Validates miR-362-5p/Sema3A as Characteristic Molecular Change in Triple-Negative Breast Cancers

Background

HER-2 is a key molecule serving as the therapeutic target, prognostic biomarker, and classification marker in breast cancer. Accurate microRNA profilings had not been conducted in purified tumor cells of HER-2-negative and HER-2-positive tissue specimens obtained from breast cancer patients.

Methods

(i) Differential expression microRNA discovery using laser capture microdissection- (LCM-) assisted specimen preparation and microRNA array chips on HER-2 overexpressing and triple-negative breast carcinoma (TNBC) subtype tissues, (ii) differential expression microRNA validation by quantitative real-time PCR, and (iii) independent validation on tissue microarray.

Results

Five microRNAs (miR-20a-5p, miR-221-3p, miR-362-5p, miR-502-3p, and miR-222-3p) were screened and validated as upregulated microRNAs in TNBC cells comparing to HER-2 overexpressing cells using a microRNA array (5 cases in each group) and quantitative real-time PCR (20 cases in each group). The expression difference of miR-362-5p had the most significant statistical significance (p = 0.0016) among the five microRNAs. The expression of miR-362-5p and its target gene Sema3A was further analyzed using in situ hybridization (ISH) and immunohistochemistry on standard tissue sections (n = 150). 70.8% of HER-2-negative cells showed moderate expression of miR-362-5p whereas 20.4% HER-2-negative cells correlated with strong expression of miR-362-5p (p < 0.0001). The proportion of patients with moderate/strong miR-362-5p expression in luminal, HER-2 overexpressing, and TNBC subtypes were 53.2%, 22.2%, and 74.3%, respectively (p = 0.0002). High miR-362-5p expressers had shorter overall survival in the univariate analysis (p = 0.046). There was a significant negative correlation between miR-362-5p and Sema3A expression (p < 0.0001). The patients with negative/weak Sema3A protein expression had poorer prognosis than those with moderate (HR: 3.723, p = 0.021) or strong (HR: 3.966, p = 0.013) Sema3A protein expression in the multivariate analysis.

Conclusions

miR-362-5p/Sema3A might provide a promising therapeutic pathway and represents a candidate therapeutic target of the TNBC subtype.

Transactivation of Met signalling by semaphorin4D in human placenta: implications for the pathogenesis of preeclampsia

OBJECTIVE

The signalling of the receptor tyrosine kinase Met is critical in promoting trophoblast cell invasion, and the deficiency in HGF/Met signalling is associated with preeclampsia. The semaphorin family member semaphorin4D (sema4D) and its receptor Plexin-B1 have been reported to control tumour cell invasion by coupling with Met. We hypothesized that sema4D/Plexin-B1 may promote trophoblast invasion by activating Met, and downregulation of sema4D/Plexin-B1 may account for the deficiency in Met signalling in preeclamptic placenta.

METHODS

In this study, Met and Erk activation and the expression of sema4D/Plexin-B1 in normal and preeclamptic placentas were comparably measured. The role of sema4D in trophoblast cell invasion and tubulogenesis was examined in vitro using the Transwell invasion assay and tube formation assay in trophoblast-endothelial cell co-culture model.

RESULTS

Met, sema4D and Plexin-B1 co-localized in various subtypes of human trophoblast cells, including villous trophoblasts and extravillous trophoblasts (EVTs). In early-onset preeclampsia (E-PE) placentas, the phosphorylated Met and Erk as well as sema4D and Plexin-B1 were much lower than those in gestational week-matched preterm-labour (PTL) placentas. In human trophoblast HTR8/SVneo cell line, sema4D could promote Met and Erk phosphorylation as well as enhance trophoblast cell invasion and tubulogenesis with endothelial cells. Moreover, the effect of sema4D on HTR8/SVneo could be blocked by knocking down Met with specific siRNA.

CONCLUSION

The crosstalk between sema4D and Met could transactivate Met to promote trophoblast cell invasion and differentiation, and decreased expression of sema4D and Plexin-B1 may be responsible for the deficiency in Met signalling and the development of preeclampsia.

Expression of Semaphorin 3B (SEMA3B) in Various Grades of Endometrial Cancer

BACKGROUND SEMA3B is known as an inhibitor of angiogenesis and cell proliferation. During carcinogenesis, the loss of SEMA3B function is observed, which results in the progression of neoplastic changes. The aim of this study was to evaluate the expression profile of SEMA3B in endometrial cancer (G1-G3) in comparison to the control group and to assess whether the observed changes in expression could become a molecular marker in endometrial cancer. MATERIAL AND METHODS The study group consisted of 45 patients diagnosed with endometrial cancer (G1, 17; G2, 15; G3, 13). The control group included 15 patients. SEMA3B expression was assessed using the immunohistochemical method. Statistical analysis was carried out using the Statistica 12 PL program (StatSoft, USA). It included the Kruskal-Wallis test and post hoc Dunn's test (p<0.05). RESULTS Statistically significant differences in the level of SEMA3B expression were observed between all analyzed groups. The expression pattern of SEMA3B was as follows: cancer cells G1>G2>G3; endothelial cells: G3>G1>G2; stromal cells: G2>G1>G3. CONCLUSIONS Analysis of the SEMA3B expression profile shows the complexity of neoplastic transformation, which confirms the different expression of SEMA3B in endometrial cancer cells and endothelial cells. The present results and data in the literature data suggest that SEMA3B expression indicates the progression of carcinogenesis in the context of endometrial cancer.

NR4A3 fusion proteins trigger an axon guidance switch that marks the difference between EWSR1 and TAF15 translocated extraskeletal myxoid chondrosarcomas

Extraskeletal myxoid chondrosarcoma (EMC) is a rare sarcoma histotype with uncertain differentiation. EMC is hallmarked by the rearrangement of the NR4A3 gene, which in most cases fuses with EWSR1 or TAF15. TAF15‐translocated EMC seem to feature a more aggressive course compared to EWSR1‐positive EMCs, but whether the type of NR4A3 chimera impinges upon EMC biology is still largely undefined. To gain insights on this issue, a series of EMC samples (7 EWSR1‐NR4A3 and 5 TAF15‐NR4A3) were transcriptionally profiled. Our study unveiled that the two EMC variants display a distinct transcriptional profile and that the axon guidance pathway is a major discriminant. In particular, class 4–6 semaphorins and axonal guidance cues endowed with pro‐tumorigenic activity were more expressed in TAF15‐NR4A3 tumors; vice versa, class 3 semaphorins, considered to convey growth inhibitory signals, were more abundant in EWSR1‐NR4A3 EMC. Intriguingly, the dichotomy in axon guidance signaling observed in the two tumor variants was recapitulated in in vitro cell models engineered to ectopically express EWSR1‐NR4A3 or TAF15‐NR4A3. Moreover, TAF15‐NR4A3 cells displayed a more pronounced tumorigenic potential, as assessed by anchorage‐independent growth. Overall, our results indicate that the type of NR4A3 chimera dictates an axon guidance switch and impacts on tumor cell biology. These findings may provide a framework for interpretation of the different clinical–pathological features of the two EMC variants and lay down the bases for the development of novel patient stratification criteria and therapeutic approaches. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Semaphorins and Their Receptors in Hematological Malignancies

While semaphorins were initially identified as axonal guidance cues for wiring the neural network, it was then recognized their wide relevance in tissue development and homeostasis. Notably, semaphorin activities were also extensively studied in many types of solid tumors; however, their relevance in hematological malignancies is far from understood. In this mini-review, we surveyed the current knowledge about semaphorins and their receptors in leukemias, lymphomas, and multiple myeloma. Noteworthy, current data support a promoting role for Semaphorin 4D and Neuropilin-1 in these tumors, while Semaphorin 3A seems to consistently act as oncosuppressor in leukemias and multiple myeloma. The expression levels and functional activities of SEMA3B, SEMA3F, and Neuropilin-2 have furthermore been investigated in leukemias and lymphoma cells. Herein, we reviewed the state of the art and highlighted some of the open questions to be addressed in the field.

Multifaceted Functional Role of Semaphorins in Glioblastoma

Glioblastoma (GBM) is the most malignant tumor type affecting the adult central nervous system. Despite advances in therapy, the prognosis for patients with GBM remains poor, with a median survival of about 15 months. To date, few treatment options are available and recent trials based on the molecular targeting of some of the GBM hallmark pathways (e.g., angiogenesis) have not produced any significant improvement in overall survival. The urgent need to develop more efficacious targeted therapies has led to a better molecular characterization of GBM, revealing an emerging role of semaphorins in GBM progression. Semphorins are a wide group of membrane-bound and secreted proteins, originally identified as axon guidance cues, signaling through their receptors, neuropilins, and plexins. A number of semaphorin signals involved in the control of axonal growth and navigation during development have been found to furthermore participate in crosstalk with different dysfunctional GBM pathways, controlling tumor cell proliferation, migration, and invasion, as well as tumor angiogenesis or immune response. In this review, we summarize the regulatory activities mediated by semaphorins and their receptors on the oncogenic pathways implicated in GBM growth and invasive/metastatic progression.

Deficiency in the secreted protein Semaphorin3d causes abnormal parathyroid development in mice

Primary hyperparathyroidism (PHPT) is a common endocrinopathy characterized by hypercalcemia and elevated levels of parathyroid hormone. The primary cause of PHPT is a benign overgrowth of parathyroid tissue causing excessive secretion of parathyroid hormone. However, the molecular etiology of PHPT is incompletely defined. Here, we demonstrate that semaphorin3d (Sema3d), a secreted glycoprotein, is expressed in the developing parathyroid gland in mice. We also observed that genetic deletion of Sema3d leads to parathyroid hyperplasia, causing PHPT. In vivo and in vitro experiments using histology, immunohistochemistry, biochemical, RT-qPCR, and immunoblotting assays revealed that Sema3d inhibits parathyroid cell proliferation by decreasing the epidermal growth factor receptor (EGFR)/Erb-B2 receptor tyrosine kinase (ERBB) signaling pathway. We further demonstrate that EGFR signaling is elevated in Sema3d ^-/- parathyroid glands and that pharmacological inhibition of EGFR signaling can partially rescue the parathyroid hyperplasia phenotype. We propose that because Sema3d is a secreted protein, it may be possible to use recombinant Sema3d or derived peptides to inhibit parathyroid cell proliferation causing hyperplasia and hyperparathyroidism. Collectively, these findings identify Sema3d as a negative regulator of parathyroid growth.

Downregulation of RGMA by HIF-1A/miR-210-3p axis promotes cell proliferation in oral squamous cell carcinoma

Repulsive guidance molecules comprise a group of proteins that play an important role in carcinogenesis through interactions with their receptors, but their function in oral squamous cell carcinoma (OSCC) is unclear. Here, we investigated the potential role of the RGM family members in oral cancer pathogenesis. Our study showed that only RGMA was significantly downregulated in the OSCC tissues analyzed by TCGA and validated this finding in OSCC cells. The decreased expression of RGMA was strongly associated with the T stage and with poor prognosis. The ectopic expression of RGMA significantly inhibited the proliferation of OSCC cells both in vitro and in vivo. Moreover, we confirmed that RGMA was a target of miR-210-3p in OSCC and miR-210-3p overexpression contributed to the acceleration of OSCC growth. Further experiments revealed that HIF1A specifically interacted with the promoter of miR-210-3p and enhanced its expression. In summary, our research indicates that RGMA is regulated by the HIF1A/miR-210-3p axis and inhibits OSCC cell proliferation; thus, in the future, the development of therapies that target the HIF1A/miR-210-3p/RGMA axis may aid in the treatment of aggressive cancers.

Neuroimmune semaphorins as costimulatory molecules and beyond

Several neuronal guidance proteins, known as semaphorin molecules, function in the immune system. This dual tissue performance has led to them being defined as "neuroimmune semaphorins". They have been shown to regulate T cell activation by serving as costimulatory molecules. Similar to classical costimulatory molecules, neuroimmune semaphorins are either constitutively or inducibly expressed on immune cells. In contrast to the classical costimulatory molecule function, the action of neuroimmune semaphorins requires the presence of two signals, the first one provided by TCR/MHC engagement, and the second one provided by B7/CD28 interaction. Thus, neuroimmune semaphorins serve as a "signal three" for immune cell activation and regulate the overall intensity of immune response. The current knowledge on their structures, multiple receptors, specific cell/tissue/organ expression, and distinct functions in different diseases are summarized and discussed in this review.

Silencing of semaphorin 3C suppresses cell proliferation and migration in MCF-7 breast cancer cells

Previous studies have suggested that semaphorin 3C (SEMA3C) is involved in the tumorigenesis and metastasis of a number of types of cancer. The aim of the present study was to investigate the role of SEMA3C in the proliferation and migration of MCF-7 breast cancer cells. Small interfering (si)RNA sequences targeting SEMA3C were constructed and transfected into MCF-7 cells in order to silence the expression of SEMA3C. Cell proliferation and migration were measured using CCK-8 and Transwell assays, respectively. Transfection with SEMA3C siRNA significantly downregulated the expression of SEMA3C in MCF-7 cells, and significantly suppressed cell proliferation and migration. Therefore, SEMA3C-targeted siRNA may be of potential use for the early diagnosis and treatment of breast cancer.