Semaphorin 6D Research Articles

Biological role of Semaphorin 6D in the proliferation, migration and invasion of gastric cancer

Background: To analyse how Semaphorin 6D (SEMA6D) expression and extracellular signal-regulated kinase (ERK), phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signal pathways are activated and how they influence gastric cancer proliferation, migration, and invasion. Methodology: SEMA6D expression was knocked down in human gastric cancer cells using RNA interference technology. In vitro assays were used to analyse how SEMA6D knockdown affects clone formation, migration, and invasion. ERK and PI3K/ AKT/mTOR signaling pathway related proteins were detected by immunoblotting. Results: In the si-NC group, Sema6D protein levels were higher than those in the si-1 and si-2 groups after knockdown of Sema6D, while in the si-1 group, Sema6D protein levels were higher than those in the si-2 group (P<0.05). P-PI3K, ERK/p-ERK, AKT/p-AKT, and mTOR/p-mTOR levels in the si-NC group were significantly higher than those in the si-1 and si-2 groups after knockdown of Sema6D (P < 0.05). It was found that scratch healing rate of SGC-7901 cells in si-NC group was higher than that in si-1 and si-2 groups, and the difference was statistically significant (P < 0.05). Conclusion: SEMA6D expression level can affect the biological behavior of gastric cancer cells. Keywords: Gastric cancer; extracellular signal-regulated kinase; semaphorin 6D; ERK and PI3K/AKT/mTOR; cell proliferation.

Semaphorin 6D tunes amygdalar circuits for emotional, metabolic, and inflammatory outputs

Regulated neural-metabolic-inflammatory responses are essential for maintaining physiological homeostasis. However, the molecular machinery that coordinates neural, metabolic, and inflammatory responses is largely unknown. Here, we show that semaphorin 6D (SEMA6D) coordinates anxiogenic, metabolic, and inflammatory outputs from the amygdala by maintaining synaptic homeostasis. Using genome-wide approaches, we identify SEMA6D as a pleiotropic gene for both psychiatric and metabolic traits in human. Sema6d deficiency increases anxiety in mice. When fed a high-fat diet, Sema6d-/- mice display attenuated obesity and enhanced myelopoiesis compared with control mice due to higher sympathetic activity via the β3-adrenergic receptor. Genetic manipulation and spatial and single-nucleus transcriptomics reveal that SEMA6D in amygdalar interneurons is responsible for regulating anxiogenic and autonomic responses. Mechanistically, SEMA6D is required for synaptic maturation and γ-aminobutyric acid transmission. These results demonstrate that SEMA6D is important for the normal functioning of the neural circuits in the amygdala, coupling emotional, metabolic, and inflammatory responses.

The Role of Semaphorin 6D (Sema6D) in Non-Muscle-Invasive Bladder Cancer-A Preliminary Study on Human Plasma and Urine.

The incidence of bladder cancer worldwide in the last three decades has been increasing in both men and women. So far, there is no established non-invasive bladder cancer biomarker in daily clinical practice. Semaphorin 6D (sema6D) is a transmembrane protein that belongs to the class VI semaphorins. The aim of this study was to evaluate for the first time the potential role of sema6D in bladder cancer. The study group consisted of 40 patients with non-muscle-invasive bladder cancer (NMIBC) and the control group of 20 patients without malignancies. There was a statistically significantly higher urinary sema6D concentration in patients than controls (p < 0.05) but no significant difference in plasma 6D. There were no statistically significant differences in urinary or plasma concentration of sema6D between low- or high-grade cancer and according to the tumor stage in TNM classification. There was a statistically significant negative correlation between plasma sema6D and age of patients (R = -0.6; p = 0.019). Plasma sema6D does not seem to be useful in the clinical practice at this point. However, the urinary sema6D concentration could potentially serve as a marker of NMIBC used for diagnostic purposes, monitoring, and early relapse detection or the assessment of the treatment efficacy. Urinary sema6D is probably not associated with the grading or staging of NMIBC, so it cannot be used for the prediction of disease prognosis.

Sema6D forward signaling impairs T cell activation and proliferation in head and neck cancer.

Immune checkpoint inhibitors (ICIs) are indicated for a diverse range of cancer types, and characterizing the tumor immune microenvironment is critical for optimizing therapeutic strategies, including ICIs. T cell infiltration and activation status in the tumor microenvironment greatly affects the efficacy of ICIs. Here, we show that semaphorin 6D (Sema6D) forward signaling, which is reportedly involved in coordinating the orientation of cell development and migration as a guidance factor, impaired the infiltration and activation of tumor-specific CD8+ T cells in murine oral tumors. Sema6D expressed by nonhematopoietic cells was responsible for this phenotype. Plexin-A4, a receptor for Sema6D, inhibited T cell infiltration and partially suppressed CD8+ T cell activation and proliferation induced by Sema6D stimulation. Moreover, mouse oral tumors, which are resistant to PD-1-blocking treatment in wild-type mice, showed a response to the treatment in Sema6d-KO mice. Finally, analyses of public data sets of human head and neck squamous cell carcinoma, pan-cancer cohorts, and a retrospective cohort study showed that SEMA6D was mainly expressed by nonhematopoietic cells such as cancer cells, and SEMA6D expression was significantly negatively correlated with CD8A, PDCD1, IFNG, and GZMB expression. Thus, targeting Sema6D forward signaling is a promising option for increasing ICI efficacy.

Sema6D Promotes TREM2‐dependent Phagocytosis in Human iPSC‐derived Microglia

AbstractBackgroundMicroglia mediate key functions in inflammation and phagocytic clearance central to Alzheimer’s disease (AD). Semaphorins and their receptors, plexins and neuropilins, are best known for their role in axon guidance, but emerging roles include the regulation of innate immunity. Semaphorin receptors are highly expressed in microglia, including those encoded by AD risk genes discovered through genome‐wide association studies (e.g. PLXNA4 and PLCγ2). We investigate the function of semaphorin 6D (Sema6D) and interacting receptors in human iPSC‐derived microglia (iMG).MethodWe generated TREM2 knockout (KO) human iPSCs using CRISPR/Cas9. Following differentiation to iMG, we used a proximity labeling approach to demonstrate the interaction of known Sema6D receptors (Plexin‐A1 or Plexin‐A4) with TREM2. WT and KO cells were treated with Sema6D to assay (i) phagocytosis activity via live‐cell imaging and (ii) secretion of inflammatory cytokines via multiplex immunoassays (iii) downstream signaling events.ResultWe demonstrated that Sema6D promotes phagocytic uptake of oligomeric Aβ, and human synaptosomes, as well as significantly increases secretion of several inflammatory cytokines including IL‐1β, IL‐6, TNF‐α and IL‐8. TREM2 KO abrogates Sema6D‐induced cellular changes in iMG. Plexin‐A1 and Plexin‐A4 interact with TREM2 in the intact cell.ConclusionSema6D is a novel ligand for microglial Plexin‐A1and Plexin‐A4 and likely mediates signaling via a co‐receptor complex harboring TREM2. Sema6D is a regulator of microglial phagocytosis and cytokine release in a TREM2‐dependent manner, suggesting a Sema6D‐Plexin/TREM2 pathway as a novel therapeutic target for AD.

Semaphorin 6D regulate corralling, hematoma compaction and white matter injury in mice after intracerebral hemorrhage

ObjectivesThe Semaphorin 6D (SEMA6D) shows important roles in cell guidance and lipid metabolism, but the effects and mechanisms of SEMA6D on tissue repair, white matter injury and the recovery of neurological function after intracerebral hemorrhage have not been well studied. Materials and MethodsIn this study, the autologous whole blood injection model of intracerebral hemorrhage was established in C57 male mice. SEMA6D knockout CRISPR utilized in the study. Assessments included neurological score evaluation and immunofluorescence. ResultsSEMA6D increased and peaked at 7d after intracerebral hemorrhage, and mainly located in neurons, microglia and astrocytes. SEMA6D knockout CRISPR aggravated neurological function and showed signs of poorer corralling and hematoma resolution, with more compartments of well-established physical barrier and more extensive GFAP positive astrocytic border. Furthermore, SEMA6D can prevent the decrease of NF-H in the peri-hematoma region, while SEMA6D knockout aggravated WMI. ConclusionsOur study suggested that SEMA6D could influence the recovery of neurological function by regulating the corralling, hematoma compaction and WMI in mice after intracerebral hemorrhage.

Semaphorin 6D–expressing mesenchymal cells regulate IL-10 production by ILC2s in the lung

Group 2 innate lymphoid cells (ILC2s) have been implicated in both physiologic tissue remodeling and allergic pathology, yet the niche signaling required for ILC2 properties is poorly understood. Here, we show that an axonal guidance cue semaphorin 6D (Sema6D) plays critical roles in the maintenance of IL-10-producing ILC2s. Sema6d -/- mice exhibit a severe steady-state reduction in ILC2s in peripheral sites such as the lung, visceral adipose tissue, and mesentery. Interestingly, loss of Sema6D results in suppressed alarmin-driven type 2 cytokine production but increased IL-10 production by lung ILC2s both in vitro and in vivo. Consequently, Sema6d -/- mice are resistant to the development of allergic lung inflammation. We further found that lung mesenchymal cells highly express Sema6D, and that niche-derived Sema6D is responsible for these phenotypes through plexin A1. Collectively, these findings suggest that niche-derived Sema6D is implicated in physiological and pathological characteristics of ILC2s.

SEMA6D, Negatively Regulated by miR-7, Contributes to C28/I2 chondrocyte's Catabolic and Anabolic Activities via p38 Signaling Pathway.

MiR-7 has been recognized as an osteoarthritis (OA-)-promoting factor, but the specific downstream pathway of miR-7 still remains unknown. Further investigation of the molecular regulatory mechanism of miR-7 might help develop a novel therapeutic method for OA. In this study, we revealed that Semaphorin 6D (SEMA6D) was a direct target gene of miR-7 and presented a negative regulatory relation with SEMA6D in vitro and in vivo. SEMA6D could improve OA in rat OA models, as indicated by H&E and Safranin O-Fast green staining, and also μCT analysis. Further evaluation of SEMA6D suggested that SEMA6D promotes the anabolism and reduces the catabolism of C28/I2 chondrocytes via inhibiting the activation of the p38 pathway. The present research illustrated that SEMA6D is a negatively regulatory factor of miR-7 and a pivotal mediator of catabolism and anabolism in C28/I2 chondrocytes. SEMA6D exerts its function via inhibiting the activation of the p38 pathway.

Semaphorin 6D as an independent predictor for better prognosis in clear cell renal cell carcinoma

IntroductionClear cell renal cell carcinoma (ccRCC) is the most common type of RCC and is associated with poor survival. However, the mechanisms underlying its development have not been thoroughly investigated. Semaphorin 6D (SEMA6D) is differentially expressed in various cancers, including lung adenocarcinoma and colorectal cancer. However, the role and mechanism of SEMA6D in ccRCC remain unexplored. Materials and methodsWe obtained 25 pairs of ccRCC tissue samples and 57 urine samples from patients with ccRCC and 52 urine samples from healthy volunteers. We performed RNA sequencing and compared the results with data from The Cancer Genome Atlas database to identify our gene of interest, SEMA6D. To verify the differential expression of SEMA6D, we used real-time quantitative polymerase chain reaction, immunohistochemistry, and enzyme-linked immunosorbent assay. Finally, we conducted in vitro proliferation, migration and invasion experiments. ResultsSEMA6D expression was significantly lower in ccRCC tissue compared to that in normal tissue. Comparative analysis of our results with data from online databases revealed that the expression level of SEMA6D in ccRCC tissue correlated with the clinical stage and pathological grade of ccRCC. Furthermore, higher SEMA6D expression was associated with improved quality of life of patients with ccRCC. In addition, the diagnostic value of SEMA6D was confirmed using data from two Gene Expression Omnibus ccRCC databases. The results showed that SEMA6D can be used as a predictor for ccRCC diagnosis, with an area under the curve of 0.9642. ConclusionSEMA6D may serve as a diagnostic and prognostic biomarker for ccRCC.

SEMA6D Differentially Regulates Proliferation, Migration, and Invasion of Breast Cell Lines.

Semaphorin 6D (SEMA6D), a member of the class 6 semaphorin family, is a membrane-associated protein that plays a key role in the development of cardiac and neural tissues. A growing body of evidence suggests that SEMA6D is also involved in tumorigenesis. In breast cancer, high SEMA6D levels are correlated with better survival rates. However, very little is known about the functional significance of SEMA6D in breast tumorigenesis. In the present study, we aimed to investigate the effects of SEMA6D expression on the normal breast cell line MCF10A and the breast cancer cell lines MCF7 and MDA MB 231. We demonstrated that SEMA6D expression increases the proliferation of MCF10A cells, whereas the opposite effect was observed in MCF7 cells. SEMA6D expression induced anchorage-independent growth in both cancer cell lines. Furthermore, migration of MCF10A and MCF7 cells and invasion of MDA MB 231 cells were elevated in response to SEMA6D overexpression. Accordingly, the genes related to epithelial-mesenchymal transition (EMT) were altered by SEMA6D expression in MCF10A and MCF7 cell lines. Finally, we provided evidence that SEMA6D levels were associated with the expression of the cell cycle, EMT, and Notch signaling pathway-related genes in breast cancer patients’ data. We showed for the first time that SEMA6D overexpression has cell-specific effects on the proliferation, migration, and invasion of normal and cancer breast cell lines, which agrees with the gene expression data of clinical samples. This study lays the groundwork for future research into understanding the functional importance of SEMA6D in breast cancer.

Retinal Pigment Epithelium and Neural Retinal Progenitors Interact via Semaphorin 6D to Facilitate Optic Cup Morphogenesis.

Cell movement propels embryonic tissues to acquire shapes required for mature function. The movements are driven both by acto-myosin signaling and by cells interacting with the extracellular matrix (ECM). Unknown is whether cell-cell interactions within a tissue are also required, and the molecular mechanisms by which such communication might occur. Here, we use the developing visual system of zebrafish as a model to understand the role cell-cell communication plays in tissue morphogenesis in the embryonic nervous system. We identify that cell-cell-mediated contact between two distinct cell populations, progenitors of the neural retina and retinal pigment epithelium (RPE), facilitates epithelial flow to produce the mature cupped retina. We identify for the first time the need in eye morphogenesis for distinct populations of progenitors to interact, and suggest a novel role for a member of a key developmental signaling family, the transmembrane Semaphorin6d, as mediating communication between distinct cell types to control tissue morphogenesis.

Screening and identification of biomarkers associated with the diagnosis and prognosis of lung adenocarcinoma.

BackgroundIn this study, we aimed to identify the pathogenesis and prognostic biomarkers of lung adenocarcinoma (LUAD).MethodsDifferentially expressed mRNAs (DEmRNAs) and single nucleotide polymorphism (SNP) mutant genes were screened. In addition, enrichment and protein‐protein interaction (PPI) network analyses of the SNP‐mutated genes were performed. Thereafter, the correlation between gene mutation and expression was analyzed. Finally, the mutated genes associated with LUAD prognosis were validated on the basis of The Cancer Genome Atlas (TCGA) database.ResultsA total of 2502 DEmRNAs were initially screened in this study. We identified 756 SNP‐mutated genes from more than 30 cases. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the mutated genes involved in LUAD were mainly associated with the ECM‐receptor interaction, focal adhesion, and calcium signaling pathways. Tumor protein p53 (TP53) and neurexin 1 (NRXN1) with the higher degree were chosen as the hub genes in the PPI network. In addition, the correlation analysis revealed six genes, including assembly factor for spindle microtubules (ASPM), centromere protein F (CENPF), contactin 3 (CNTN3), catenin delta 2 (CTNND2), PKHD1 like 1 (PKHD1L1), and semaphorin 6D (SEMA6D), and three SNP mutations at ASPM rs368020495, CENPF rs762653487, and PKHD1L1 rs768349010 sites that were found to be associated with LUAD prognosis. Further validation showed that among the aforementioned six mutated genes, CENPF was upregulated and SEMA6D was downregulated.Conclusion CENPF, SEMA6D, TP53, and NRXN1 were found to be closely associated with the development of LUAD.

MiR-23a-3p is a Key Regulator of IL-17C-Induced Tumor Angiogenesis in Colorectal Cancer.

MicroRNAs (miRNAs) have emerged as key players in tumor angiogenesis. Interleukin-17C (IL-17C) was identified to promote colorectal cancer (CRC) progression. Therefore, we aimed to investigate the effect of IL-17C on tumor angiogenesis, the involvement of miR-23a-3p in IL-17C signaling, and the direct target gene of miR-23a-3p in CRC. In vitro and ex vivo angiogenesis, a mouse xenograft experiment, and immunostaining were performed to test the effect of IL-17C on tumor angiogenesis. ELISA, quantitative real time PCR, and gene silencing were used to uncover the underlying mechanism. IL-17C induced angiogenesis of intestinal endothelial cells, subsequently enhancing cell invasion and migration of DLD-1 cells. IL-17C-stimulated DLD-1 cells produced vascular endothelial growth factor (VEGF) to enhance angiogenesis. Moreover, IL-17C markedly accelerated xenograft tumor growth, which was manifested by substantially reduced tumor growth when treated with the VEGF receptor 2 inhibitor Ki8751. Accordingly, Ki8751 suppressed the expression of IL-17C-stimulated PECAM and VE-cadherin in xenografts. Furthermore, IL-17C activated STAT3 to increase the expression of miR-23a-3p that suppressed semaphorin 6D (SEMA6D) expression, thereby permitting VEGF production. Taken together, our study demonstrates that IL-17C promotes tumor angiogenesis through VEGF production via a STAT3/miR-23a-3p/SEMA6D axis, suggesting its potential as a novel target for anti-CRC therapy.

Vascular Endothelial Growth Factor Production by Interleukin‐17C‐Stimulated Colorectal Cancer Cells Is Dependent on the STAT3/miR‐23a‐3p Signaling

Recent studies have shown that interleukin‐17C (IL‐17C) is associated with tumor initiation and progression of colorectal cancer (CRC). However, the detailed mechanism of action remains to be elucidated. We aimed to investigate the effect of IL‐17C on angiogenesis and delineate the direct target genes of IL‐17C signaling in CRC. Aims were tested by using angiogenesis assays, murine xenograft experiments, immunohistochemical staining, gene silencing, quantitative real time PCR, ELISA, and western blot analysis. IL‐17C induced angiogenesis of intestinal endothelial cells, subsequently enhancing cell invasion and migration of DLD‐1 cells. IL‐17C‐conditioned DLD‐1 cells enhanced angiogenesis by secreting vascular endothelial growth factor (VEGF). Moreover, IL‐17C significantly increased xenograft tumor growth via VEGF production, but treatment with the VEGF receptor 2 inhibitor Ki8751 ameliorated its tumor promoting activity. IL‐17C also increased levels of PECAM and VE‐cadherin in tumor tissues, which was suppressed by Ki8751. Furthermore, IL‐17C increased miR‐23a‐3p expression via STAT3 phosphorylation. Accordingly, miR‐23a‐3p suppressed semaphorin 6D (SEMA6D) expression, enabling VEGF induction. Therefore, our data showed that IL‐17C promotes tumorigenesis and angiogenesis through VEGF production via the STAT3/miR‐23a‐3p/SEMA6D axis, suggesting its potential as a novel target for anti‐CRC therapy.Support or Funding InformationThis work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2019R1A2C1010536 to E.I.).

Semaphorin 6D reverse signaling controls macrophage lipid metabolism and anti-inflammatory polarization.

Polarization of macrophages into pro-inflammatory or anti-inflammatory states has distinct metabolic requirements, with mechanistic target of rapamycin (mTOR) kinase signaling playing a critical role. However, it remains unclear how mTOR regulates metabolic status to promote polarization of these cells. Here we show that an mTOR-Semaphorin 6D (Sema6D)-Peroxisome proliferator receptor γ (PPARγ) axis plays critical roles in macrophage polarization. Inhibition of mTOR or loss of Sema6D blocked anti-inflammatory macrophage polarization, concomitant with severe impairments in PPARγ expression, uptake of fatty acids, and lipid metabolic reprogramming. Macrophage expression of the receptor Plexin-A4 is responsible for Sema6D-mediated anti-inflammatory polarization. We found that a tyrosine kinase, c-Abl, which associates with the cytoplasmic region of Sema6D, is required for PPARγ expression. Furthermore, Sema6D is important for generation of intestinal resident CX3CR1hi macrophages and prevents development of colitis. Collectively, these findings highlight crucial roles for Sema6D reverse signaling in macrophage polarization, coupling immunity, and metabolism via PPARγ.

TORching a semaphore for alternative macrophage activation

The metabolic master regulator mTORC1 is shown to promote alternative macrophage activation via Semaphorin 6D reverse signaling and reprogramming of lipid metabolism.

Long non-coding RNAs RP5-821D11.7, APCDD1L-AS1 and RP11-277P12.9 were associated with the prognosis of lung squamous cell carcinoma.

Lung squamous cell carcinoma (LUSC), a type of non-small cell lung carcinoma, has a poor therapeutic response, high relapse rate and poor prognosis. The present study was designed to reveal the key long non-coding RNAs (lncRNAs) associated with the prognosis of LUSC. The lncRNA expression profiles of LUSC and adjacent samples were downloaded from The Cancer Genome Atlas database. Based on the edgeR and DEseq packages, the differentially expressed lncRNAs (DELs) between LUSC and adjacent samples were obtained and the intersecting DELs were regarded as significant DELs. Subsequently, a prognostic risk model was established using Cox regression analysis and its classification effect was detected by survival analysis. Using survival analysis, the effect of the prognostic risk model was assessed in the validation set and other types of cancer. Finally, the co-expression genes of key lncRNAs were screened using the Multi-Experiment Matrix tool and the STRING database, and their functions were predicted via enrichment analysis using the Database for Annotation, Visualization and Integrated Discovery tool. A total of 2,041 significant DELs between LUSC and adjacent samples were screened. The prognostic risk model consisting of RP5-821D11.7, APCDD1L-AS1 and RP11-277P12.9 was established, which had a good classification effect. Cox multivariate regression analysis demonstrated that risk score may serve as an independent prognostic factor. Furthermore, certain co-expression genes of RP5-821D11.7 (including proliferating cell nuclear antigen), APCDD1L-AS1 (including semaphorin 5A, semaphorin 6D, ADAMTS like 1, ADAM metallopeptidase with thrombospondin type 1 motif 6, slit guidance ligand 3, and tenascin C) and RP11-277P12.9 (including Wnt family member 2B) were identified. Additionally, ‘positive regulation of cell migration’ and ‘proteinaceous extracellular matrix’ were enriched. In conclusion, the expression levels of the lncRNAs RP5-821D11.7, APCDD1L-AS1 and RP11-277P12.9 may affect the prognosis of LUSC.

Expression of semaphorin 6D and its receptor plexin-A1 in gastric cancer and their association with tumor angiogenesis.

The semaphorin and plexin family of ligands and receptor proteins provides important axon growth and guidance cues required for development. In recent years, studies have expanded their role in the regulation of cardiac morphogenesis and tumorigenesis. However, the mechanism responsible for their role in regulating cancer development and progression has not been clarified. In the present study, semaphorin 6D (Sema6D) and its receptor plexin-A1 were identified to be expressed at high levels in vascular epithelial cells within gastric cancer, and were positively correlated with vascular endothelial growth factor receptor 2 (VEGFR2). These findings verify our hypothesis that Sema6D and plexin-A1 may be closely associated with tumor angiogenesis. Combined with experimental observations in the MGC803 gastric cancer cell line, it was observed that knocking down plexin-A1 signaling led to a decreased expression of VEGFR2 at the messenger RNA and protein levels. Sema6D recognized and activated plexin-A1, which subsequently activated its downstream target, VEGFR2. The activation of VEGFR2 functioned as a positive regulator of tumor angiogenesis. Our data provided an understanding of the complex signaling cascades involved in the angiogenesis-related pathway in tumor cells. In light of our observations, pharmacological interventions targeting Sema6D/plexin-A1/VEGFR2 signaling may potentially be used as a target for the development of novel anti-angiogenic drugs in gastric cancer.

Microarray Expression Data Identify DCC as a Candidate Gene for Early Meningioma Progression.

Meningiomas are the most common primary brain tumors bearing in a minority of cases an aggressive phenotype. Although meningiomas are stratified according to their histology and clinical behavior, the underlying molecular genetics predicting aggressiveness are not thoroughly understood. We performed whole transcript expression profiling in 10 grade I and four grade II meningiomas, three of which invaded the brain. Microarray expression analysis identified deleted in colorectal cancer (DCC) as a differentially expressed gene (DEG) enabling us to cluster meningiomas into DCC low expression (3 grade I and 3 grade II tumors), DCC medium expression (2 grade I and 1 grade II tumors), and DCC high expression (5 grade I tumors) groups. Comparison between the DCC low expression and DCC high expression groups resulted in 416 DEGs (p-value < 0.05; fold change > 2). The most significantly downregulated genes in the DCC low expression group comprised DCC, phosphodiesterase 1C (PDE1C), calmodulin-dependent 70kDa olfactomedin 2 (OLFM2), glutathione S-transferase mu 5 (GSTM5), phosphotyrosine interaction domain containing 1 (PID1), sema domain, transmembrane domain (TM) and cytoplasmic domain, (semaphorin) 6D (SEMA6D), and indolethylamine N-methyltransferase (INMT). The most significantly upregulated genes comprised chromosome 5 open reading frame 63 (C5orf63), homeodomain interacting protein kinase 2 (HIPK2), and basic helix-loop-helix family, member e40 (BHLHE40). Biofunctional analysis identified as predicted top upstream regulators beta-estradiol, TGFB1, Tgf beta complex, LY294002, and dexamethasone and as predicted top regulator effectors NFkB, PIK3R1, and CREBBP. The microarray expression data served also for a comparison between meningiomas from female and male patients and for a comparison between brain invasive and non-invasive meningiomas resulting in a number of significant DEGs and related biofunctions. In conclusion, based on its expression levels, DCC may constitute a valid biomarker to identify those benign meningiomas at risk for progression.

SEMA6D Expression and Patient Survival in Breast Invasive Carcinoma.

Breast cancer (BC) is the second most common cancer diagnosed in American women and is also the second leading cause of cancer death in women. Research has focused heavily on BC metastasis. Multiple signaling pathways have been implicated in regulating BC metastasis. Our knowledge of regulation of BC metastasis is, however, far from complete. Identification of new factors during metastasis is an essential step towards future therapy. Our labs have focused on Semaphorin 6D (SEMA6D), which was implicated in immune responses, heart development, and neurogenesis. It will be interesting to know SEMA6D-related genomic expression profile and its implications in clinical outcome. In this study, we examined the public datasets of breast invasive carcinoma from The Cancer Genome Atlas (TCGA). We analyzed the expression of SEMA6D along with its related genes, their functions, pathways, and potential as copredictors for BC patients' survival. We found 6-gene expression profile that can be used as such predictors. Our study provides evidences for the first time that breast invasive carcinoma may contain a subtype based on SEMA6D expression. The expression of SEMA6D gene may play an important role in promoting patient survival, especially among triple negative breast cancer patients.