SEMA3A

Gene Summary

Gene:SEMA3A; semaphorin 3A
Aliases: HH16, SemD, COLL1, SEMA1, SEMAD, SEMAL, coll-1, Hsema-I, SEMAIII, Hsema-III
Location:7q21.11
Summary:This gene is a member of the semaphorin family and encodes a protein with an Ig-like C2-type (immunoglobulin-like) domain, a PSI domain and a Sema domain. This secreted protein can function as either a chemorepulsive agent, inhibiting axonal outgrowth, or as a chemoattractive agent, stimulating the growth of apical dendrites. In both cases, the protein is vital for normal neuronal pattern development. Increased expression of this protein is associated with schizophrenia and is seen in a variety of human tumor cell lines. Also, aberrant release of this protein is associated with the progression of Alzheimer's disease. [provided by RefSeq, Jul 2008]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:semaphorin-3A
Source:NCBIAccessed: 31 August, 2019

Ontology:

What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 01 September 2019 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

Tag cloud generated 31 August, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: SEMA3A (cancer-related)

Tominaga K, Minato H, Murayama T, et al.
Semaphorin signaling via MICAL3 induces symmetric cell division to expand breast cancer stem-like cells.
Proc Natl Acad Sci U S A. 2019; 116(2):625-630 [PubMed] Free Access to Full Article Related Publications
Cancer stem-like cells (CSCs) are expanded in the CSC niche by increased frequency of symmetric cell divisions at the expense of asymmetric cell divisions. The symmetric division of CSCs is important for the malignant properties of cancer; however, underlying molecular mechanisms remain largely elusive. Here, we show a cytokine, semaphorin 3 (Sema3), produced from the CSC niche, induces symmetric divisions of CSCs to expand the CSC population. Our findings indicate that stimulation with Sema3 induced sphere formation in breast cancer cells through neuropilin 1 (NP1) receptor that was specifically expressed in breast CSCs (BCSCs). Knockdown of

Luo D, Zhang Z, Zhang Z, et al.
Aberrant Expression of miR-362 Promotes Lung Cancer Metastasis through Downregulation of Sema3A.
J Immunol Res. 2018; 2018:1687097 [PubMed] Free Access to Full Article Related Publications
miR-362 is a recently discovered member of the microRNA family, and it modulates a variety of physical activities and plays an important role in the occurrence and development of many tumors. However, the biological functions of hsa-miR-362-5p in non-small-cell lung carcinoma (NSCLC) are unknown. Transwell assay and colony formation were used to determine the migration, invasion, and proliferation of NSCLC cells

Kiso M, Tanaka S, Saji S, et al.
Long isoform of VEGF stimulates cell migration of breast cancer by filopodia formation via NRP1/ARHGAP17/Cdc42 regulatory network.
Int J Cancer. 2018; 143(11):2905-2918 [PubMed] Free Access to Full Article Related Publications
VEGF stimulates endothelial cells as a key molecule in angiogenesis. VEGF also works as a multifunction molecule, which targets a variety of cell members in the tumor microenvironment. We aimed to reveal VEGF-related molecular mechanisms on breast cancer cells. VEGF-knocked-out MDA-MB-231 cells (231

Świerczewska M, Klejewski A, Brązert M, et al.
New and Old Genes Associated with Primary and Established Responses to Paclitaxel Treatment in Ovarian Cancer Cell Lines.
Molecules. 2018; 23(4) [PubMed] Free Access to Full Article Related Publications
Development of drug resistance is the main reason for low chemotherapy effectiveness in treating ovarian cancer. Paclitaxel (PAC) is a chemotherapeutic drug used in the treatment of this cancer. We analysed the development of PAC resistance in two ovarian cancer cell lines. Exposure of drug-sensitive cell lines (A2780 and W1) to PAC was used to determine the primary response. An established response was determined in PAC-resistant sublines of the A2780 and W1 cell lines. qRT-PCR was performed to measure the expression levels of specific genes. We observed decreased expression of the

Tian W, Li Y, Zhang J, et al.
Combined analysis of DNA methylation and gene expression profiles of osteosarcoma identified several prognosis signatures.
Gene. 2018; 650:7-14 [PubMed] Related Publications
Osteosarcoma (OS) is a common primary malignancy in children and adolescents with relative high survival rate after chemotherapy. While, the toxicity of chemotherapy and personalized different response to chemotherapy makes it difficult for the selection of therapeutics and improvement of diagnosis. In this study, we conducted a combined analysis of two types of microarray datasets (gene expression and DNA methylation) from the Gene Expression Omnibus (GEO). Differential methylation sites (DMS) were identified by the IMA package and differential expression genes (DEGs) were screened out via the limma package. A total of 11,242 DMS (corresponding to 3080 genes (DMGs)) and 337 DEGs, with 40 overlaps (OS genes) between DEGs and DMGs, were identified. Enriched functions of OS genes were obtained through the Database for Annotation, Visualization and Integrated Discovery (DAVID). The OS genes were mainly enriched in the biological processes related to inflammatory/immune response and Pertussis pathways and Hematopoietic cell lineage pathways. Besides, OS-specific disease network was obtained, and found that UBS and NRF1 were regulated by multiple OS genes. Kaplan Meier analysis of OS genes identified BHMT2, DOCK2, DNALI1 and RIPK3 as significant OS survival-related genes. SEMA3A and PRAME are included in the 40 OS genes and within the top 10 most up-regulated DEGs. Their expression changes were further validated in U2OS osteosarcoma cell lines and hOB normal cell lines through quantitative PCR (qPCR) and consistent result with microarray analysis was obtained. Based on this study, some novel targets were identified for OS, which would be helpful in its early diagnosis and treatment.

Lee J, Shin YJ, Lee K, et al.
Anti-SEMA3A Antibody: A Novel Therapeutic Agent to Suppress Glioblastoma Tumor Growth.
Cancer Res Treat. 2018; 50(3):1009-1022 [PubMed] Free Access to Full Article Related Publications
Purpose: Glioblastoma (GBM) is classified as one of the most aggressive and lethal brain tumor. Great strides have been made in understanding the genomic and molecular underpinnings of GBM, which translated into development of new therapeutic approaches to combat such deadly disease. However, there are only few therapeutic agents that can effectively inhibit GBM invasion in a clinical framework. In an effort to address such challenges, we have generated anti-SEMA3A monoclonal antibody as a potential therapeutic antibody against GBM progression.
Materials and Methods: We employed public glioma datasets, Repository of Molecular Brain Neoplasia Data and The Cancer Genome Atlas, to analyze SEMA3AmRNA expression in human GBM specimens. We also evaluated for protein expression level of SEMA3A via tissue microarray (TMA) analysis. Cell migration and proliferation kinetics were assessed in various GBM patient-derived cells (PDCs) and U87-MG cell-line for SEMA3A antibody efficacy. GBM patient-derived xenograft (PDX) models were generated to evaluate tumor inhibitory effect of anti-SEMA3A antibody in vivo.
Results: By combining bioinformatics and TMA analysis, we discovered that SEMA3A is highly expressed in human GBM specimens compared to non-neoplastic tissues. We developed three different anti-SEMA3A antibodies, in fully human IgG form, through screening phage-displayed synthetic antibody library using a classical panning method. Neutralization of SEMA3A significantly reduced migration and proliferation capabilities of PDCs and U87-MG cell line in vitro. In PDX models, treatment with anti-SEMA3A antibody exhibited notable tumor inhibitory effect through down-regulation of cellular proliferative kinetics and tumor-associated macrophages recruitment.
Conclusion: In present study, we demonstrated tumor inhibitory effect of SEMA3A antibody in GBM progression and present its potential relevance as a therapeutic agent in a clinical framework.

Richardson TE, Shen ZJ, Kanchwala M, et al.
Aggressive Behavior in Silent Subtype III Pituitary Adenomas May Depend on Suppression of Local Immune Response: A Whole Transcriptome Analysis.
J Neuropathol Exp Neurol. 2017; 76(10):874-882 [PubMed] Related Publications
Silent subtype III pituitary adenomas (SS-3) are clinically nonfunctional adenomas that are more aggressive in terms of invasion and risk of recurrence than their conventional null cell counterparts. We previously showed that these tumors can be distinguished by immunohistochemistry based on the identification of a markedly enlarged and fragmented Golgi apparatus. To understand the molecular correlates of differential aggressiveness, we performed whole transcriptome sequencing (RNAseq) on 4 SS-3 and 4 conventional null cell adenomas. The genes that were highly upregulated in all the SS-3 adenomas included 2 secreted proteins involved in the suppression of T-lymphocyte activity, i.e., ARG2 (multiple testing adjusted padj = 1.5 × 10-3) and SEMA3A (padj = 3.3 × 10-3). Highly downregulated genes in all the SS-3 adenomas included HLA-B (padj = 3.3 × 10-6), suggesting reduced antigen presentation by the adenoma to cytotoxic T-cells. Quantitative RT-PCR of these genes performed on the adenoma samples supported the RNAseq results. We also found a relative decrease in the overall concentration of T-lymphocytes in the SS-3 tumors. These results suggest that SS-3 adenomas actively suppress the immune system and raise the possibility that they may be treatable with immune checkpoint inhibitors or nonspecific cancer immunotherapies.

Januchowski R, Sterzyńska K, Zawierucha P, et al.
Microarray-based detection and expression analysis of new genes associated with drug resistance in ovarian cancer cell lines.
Oncotarget. 2017; 8(30):49944-49958 [PubMed] Free Access to Full Article Related Publications
PURPOSE: The present study is to discover a new genes associated with drug resistance development in ovarian cancer.
METHODS: We used microarray analysis to determine alterations in the level of expression of genes in cisplatin- (CisPt), doxorubicin- (Dox), topotecan- (Top), and paclitaxel- (Pac) resistant variants of W1 and A2780 ovarian cancer cell lines. Immunohistochemistry assay was used to determine protein expression in ovarian cancer patients.
RESULTS: We observed alterations in the expression of 22 genes that were common to all three cell lines that were resistant to the same cytostatic drug. The level of expression of 13 genes was upregulated and that of nine genes was downregulated. In the CisPt-resistant cell line, we observed downregulated expression of ABCC6, BST2, ERAP2 and MCTP1; in the Pac-resistant cell line, we observe upregulated expression of ABCB1, EPHA7 and RUNDC3B and downregulated expression of LIPG, MCTP1, NSBP1, PCDH9, PTPRK and SEMA3A. The expression levels of three genes, ABCB1, ABCB4 and IFI16, were upregulated in the Dox-resistant cell lines. In the Top-resistant cell lines, we observed increased expression levels of ABCG2, HERC5, IFIH1, MYOT, S100A3, SAMD4A, SPP1 and TGFBI and decreased expression levels of MCTP1 and PTPRK. The expression of EPHA7, IFI16, SPP1 and TGFBI was confirmed at protein level in analyzed ovarian cancer patients..
CONCLUSIONS: The expression profiles of the investigated cell lines indicated that new candidate genes are related to the development of resistance to the cytostatic drugs that are used in first- and second-line chemotherapy of ovarian cancer.

Li X, Chen Q, Yin D, et al.
Novel role of semaphorin 3A in the growth and progression of hepatocellular carcinoma.
Oncol Rep. 2017; 37(6):3313-3320 [PubMed] Related Publications
Semaphorin 3A (SEMA3A), a secretory protein, is a founding member of the semaphorin family and functions in both the biological behavior of tumor cells and the modulation of tumor-associated macrophages. However, the role of SEMA3A in hepatocellular carcinoma (HCC) is still not well established. In the present study, we investigated the expression levels of SEMA3A in 80 HCC tissues and cell lines, using RT-qPCR, western blotting and immunohistochemistry. Expression profile analysis revealed that SEMA3A was significantly overexpressed in human HCC patients and positively correlated with the metastatic potential of HCC cells. Lentiviral transfection into PLC/PRF/5 and HCCLM3 cells was performed to stably upregulate and downregulate the expression of SEMA3A in HCC cells. Cell Counting Kit-8 (CCK-8), wound-healing and invasion assays revealed that SEMA3A promoted the proliferation and migration of HCC cells in vitro. Proteome profiler antibody microarray analysis revealed that overexpression of SEMA3A in HCC cells induced a significant increase in the expression levels of gelsolin-like capping protein (CapG), galectin-3, enolase 2 and epithelial cell adhesion molecule (EpCAM). Furthermore, the upregulation of SEMA3A in HCC cells promoted tumor growth and progression in an HCC mouse model. These results indicate that SEMA3A enhances CapG, galectin-3, enolase 2 and EpCAM expression to promote HCC progression and is a potential therapeutic target for HCC.

Hu ZQ, Zhou SL, Zhou ZJ, et al.
Overexpression of semaphorin 3A promotes tumor progression and predicts poor prognosis in hepatocellular carcinoma after curative resection.
Oncotarget. 2016; 7(32):51733-51746 [PubMed] Free Access to Full Article Related Publications
The semaphorins were originally identified as having roles as guidance cues during neural development. Class 3 semaphorins are involved in cancer progression. However, the roles of class 3 semaphorins in hepatocellular carcinoma (HCC) are unknown. We examined the expression levels of class 3 semaphorins in HCC cell lines with different metastatic potential and in carcinoma tissue samples. The results indicated that Semaphorin 3A expression was up-regulated in metastatic cell lines and in samples from patients with tumor recurrence. Cell functional studies revealed that Semaphorin 3A promoted HCC cell proliferation, migration, and invasion. Animal studies indicated that Semaphorin 3A overexpression enhanced tumor growth and lung metastasis. Semaphorin 3A also acted as a chemoattractant involved in direct recruitment of macrophages in vitro, and facilitated tumor-associated macrophage (TAM) infiltration in vivo. Multivariate analysis revealed that Semaphorin 3A expression alone, or combined with the number of TAMs, can be an independent predictor for overall survival time and time to recurrence. Overall, the results suggested that Semaphorin 3A increased TAM infiltration and promoted HCC progression. Semaphorin 3A expression alone, or combined with the number of TAMs, is a new prognostic factor and potential target for the treatment of HCC.

Cai G, Wu D, Wang Z, et al.
Collapsin response mediator protein-1 (CRMP1) acts as an invasion and metastasis suppressor of prostate cancer via its suppression of epithelial-mesenchymal transition and remodeling of actin cytoskeleton organization.
Oncogene. 2017; 36(4):546-558 [PubMed] Free Access to Full Article Related Publications
The cancer cells can acquire migration and invasion capacities during the metastasis process through the developmental regulatory program epithelial-mesenchymal-transition (EMT), and through its reverse process mesenchymal-epithelial transition cancer cells can recolonize at distant metastatic sites. Among the multifaceted effects exerted by this program, reorganization of actin cytoskeleton is the key mechanical drive for the invasive properties gained by cancer cells. Collapsin response mediator protein-1 (CRMP1) is a cytosolic phosphoprotein and originally characterized as the mediator of semaphorin 3A signaling involved in axon differentiation during neural development. Here we report that CRMP1 can act as a suppressor of tumorigenicity and metastasis in prostate cancer cells. We demonstrated that CRMP1 exhibited a decreased expression pattern in high-grade prostate cancer tissues and many prostate cancer cell lines, and its downregulation in cancer cells was attributed to histone deacetylation and direct repression of its gene by the EMT regulator Snail. Functional analyses revealed that CRMP1 suppressed EMT in prostate cancer cells, as its knockdown could trigger EMT and enhance in vitro invasion capacity, whereas its overexpression could inhibit EMT and suppress both in vitro invasion and in vivo metastasis capacities of prostate cancer cells. Moreover, CRMP1 overexpression could significantly confer resistance to EMT induced by Snail or transforming growth factor-β1 in prostatic epithelial cells and prostate cancer cells. Finally, we demonstrated that CRMP1 could associate with actin and WAVE1, an activator of actin nucleation complex Arp2/3, and also its knockdown could stabilize F-actin and trigger the formation of stress fibers in prostate cancer cells. Together, our study shows that CRMP1 acts an EMT and metastasis suppressor in prostate cancer cells via its regulation of actin polymerization and also suggests that targeting the CRMP1-actin signaling in actin organization could be a potential strategy for management of prostate cancer metastasis.

Storti P, Marchica V, Airoldi I, et al.
Galectin-1 suppression delineates a new strategy to inhibit myeloma-induced angiogenesis and tumoral growth in vivo.
Leukemia. 2016; 30(12):2351-2363 [PubMed] Related Publications
Galectin-1 (Gal-1) is involved in tumoral angiogenesis, hypoxia and metastases. Actually the Gal-1 expression profile in multiple myeloma (MM) patients and its pathophysiological role in MM-induced angiogenesis and tumoral growth are unknown. In this study, we found that Gal-1 expression by MM cells was upregulated in hypoxic conditions and that stable knockdown of hypoxia inducible factor-1α significantly downregulated its expression. Therefore, we performed Gal-1 inhibition using lentivirus transfection of shRNA anti-Gal-1 in human myeloma cell lines (HMCLs), and showed that its suppression modified transcriptional profiles in both hypoxic and normoxic conditions. Interestingly, Gal-1 inhibition in MM cells downregulated proangiogenic genes, including MMP9 and CCL2, and upregulated the antiangiogenic ones SEMA3A and CXCL10. Consistently, Gal-1 suppression in MM cells significantly decreased their proangiogenic properties in vitro. This was confirmed in vivo, in two different mouse models injected with HMCLs transfected with anti-Gal-1 shRNA or the control vector. Gal-1 suppression in both models significantly reduced tumor burden and microvascular density as compared with the control mice. Moreover, Gal-1 suppression induced smaller lytic lesions on X-ray in the intratibial model. Overall, our data indicate that Gal-1 is a new potential therapeutic target in MM blocking angiogenesis.

Wallerius M, Wallmann T, Bartish M, et al.
Guidance Molecule SEMA3A Restricts Tumor Growth by Differentially Regulating the Proliferation of Tumor-Associated Macrophages.
Cancer Res. 2016; 76(11):3166-78 [PubMed] Related Publications
Accumulation of tumor-associated macrophages (TAM) correlates with malignant progression, immune suppression, and poor prognosis. In this study, we defined a critical role for the cell-surface guidance molecule SEMA3A in differential proliferative control of TAMs. Tumor cell-derived SEMA3A restricted the proliferation of protumoral M2 macrophages but increased the proliferation of antitumoral M1, acting through the SEMA3A receptor neuropilin 1. Expansion of M1 macrophages in vivo enhanced the recruitment and activation of natural killer (NK) cells and cytotoxic CD8(+) T cells to tumors, inhibiting their growth. In human breast cancer specimens, we found that immunohistochemical levels of SEMA3A correlated with the expression of genes characteristic of M1 macrophages, CD8(+) T cells, and NK cells, while inversely correlating with established characters of malignancy. In summary, our results illuminate a mechanism whereby the TAM phenotype is controlled and identify the cell-surface molecule SEMA3A as a candidate for therapeutic targeting. Cancer Res; 76(11); 3166-78. ©2016 AACR.

Sorber R, Teper Y, Abisoye-Ogunniyan A, et al.
Whole Genome Sequencing of Newly Established Pancreatic Cancer Lines Identifies Novel Somatic Mutation (c.2587G>A) in Axon Guidance Receptor Plexin A1 as Enhancer of Proliferation and Invasion.
PLoS One. 2016; 11(3):e0149833 [PubMed] Free Access to Full Article Related Publications
The genetic profile of human pancreatic cancers harbors considerable heterogeneity, which suggests a possible explanation for the pronounced inefficacy of single therapies in this disease. This observation has led to a belief that custom therapies based on individual tumor profiles are necessary to more effectively treat pancreatic cancer. It has recently been discovered that axon guidance genes are affected by somatic structural variants in up to 25% of human pancreatic cancers. Thus far, however, some of these mutations have only been correlated to survival probability and no function has been assigned to these observed axon guidance gene mutations in pancreatic cancer. In this study we established three novel pancreatic cancer cell lines and performed whole genome sequencing to discover novel mutations in axon guidance genes that may contribute to the cancer phenotype of these cells. We discovered, among other novel somatic variants in axon guidance pathway genes, a novel mutation in the PLXNA1 receptor (c.2587G>A) in newly established cell line SB.06 that mediates oncogenic cues of increased invasion and proliferation in SB.06 cells and increased invasion in 293T cells upon stimulation with the receptor's natural ligand semaphorin 3A compared to wild type PLXNA1 cells. Mutant PLXNA1 signaling was associated with increased Rho-GTPase and p42/p44 MAPK signaling activity and cytoskeletal expansion, but not changes in E-cadherin, vimentin, or metalloproteinase 9 expression levels. Pharmacologic inhibition of the Rho-GTPase family member CDC42 selectively abrogated PLXNA1 c.2587G>A-mediated increased invasion. These findings provide in-vitro confirmation that somatic mutations in axon guidance genes can provide oncogenic gain-of-function signals and may contribute to pancreatic cancer progression.

Yamada D, Kawahara K, Ozaki M, Maeda T
Tumor cell-derived secretory factor downregulates Semaphorin-3a in osteoblasts by activating mammalian target of rapamycin pathway.
Biosci Biotechnol Biochem. 2016; 80(5):942-4 [PubMed] Related Publications
We found that conditioned medium derived from Lewis Lung Carcinoma cells down-regulated Semaphorin3a (Sema3a) mRNA expression and increased the activity of mammalian target of rapamycin complex 1 (mTORC1) in osteoblast-like MC3T3-E1 cells. Furthermore, mTORC1 inhibition with rapamycin counteracted the effect of conditioned media on Sema3a mRNA expression. These results suggest that tumor cells decrease Sema3a mRNA expression in osteoblast in an mTORC1-dependent manner.

Wang Z, Chen J, Zhang W, et al.
Axon guidance molecule semaphorin3A is a novel tumor suppressor in head and neck squamous cell carcinoma.
Oncotarget. 2016; 7(5):6048-62 [PubMed] Free Access to Full Article Related Publications
Semaphorin3A (SEMA3A), an axon guidance molecule in the nervous system, plays an inhibitory role in oncogenesis. Here, we investigated the expression pattern and biological roles of SEMA3A in head and neck squamous cell carcinoma (HNSCC) by gain-of-function assays using adenovirus transfection and recombinant human SEMA3A protein. In addition, we explored the therapeutic efficacy of SEMA3A against HNSCC in vivo. We found that lower expression of SEMA3A correlated with shorter overall survival and had independent prognostic importance in patients with HNSCC. Both genetic and recombinant SEMA3A protein inhibited cell proliferation and colony formation and induced apoptosis, accompanied by decreased cyclin E, cyclin D, CDK2, CDK4 and CDK6 and increased P21, P27, activated caspase-5 and caspase-7. Moreover, over-expression of SEMA3A suppressed migration, invasion and epithelial-to-mesenchymal transition due in part to the inhibition of NF-κB and SNAI2 in HNSCC cell lines. Furthermore, intratumoral SEMA3A delivery significantly stagnated tumor growth in a xenograft model. Taken together, our results indicate that SEMA3A serves as a tumor suppressor during HNSCC tumorigenesis and a new target for the treatment of HNSCC.

Yan-Chun L, Hong-Mei Y, Zhi-Hong C, et al.
MicroRNA-192-5p Promote the Proliferation and Metastasis of Hepatocellular Carcinoma Cell by Targeting SEMA3A.
Appl Immunohistochem Mol Morphol. 2017; 25(4):251-260 [PubMed] Related Publications
Side population (SP) cells are a small subset of cells isolated from a cultured cancer cell line with characteristics similar to those of cancer stem cells, such as high metastatic and tumorigenic potentials. However, the molecular mechanisms remain unclear for the malignant properties of SP cells. In this study, SP cells were isolated by staining cultured HCCLM3 cells with fluorescent DNA-binding dye Hoechst 33342 and sorted by flow cytometry. The proportion of SP cells was 2.79%±0.19% in the HCCLM3 cell line. Compared with non-SP cells, SP cells possessed stronger capability of sphere formation and tumorigenicity, and expressed higher levels of CD133 and CD90. Then, we found that SP cells possessed 25 upregulated and 34 downregulated microRNAs with differences of >3-fold. As one of the upregulated microRNAs, miR-192-5p was computationally predicted to target semaphorin 3A (SEMA3A), a potent suppressor of tumor angiogenesis in various cancer models. Luciferase reporter assay showed that SEMA3A was a direct target of miR-192-5p. Overexpression of miR-192-5p promoted cell proliferation and metastasis targeting SEMA3A in HCCLM3 cells. Immunohistochemical staining revealed that SEMA3A expression was significantly reverse associated with metastasis in hepatocellular carcinoma tissues. The results indicate that miR-192-5p contributes to targeting SEMA3A in HCCLM3 cells, and this may be used as a target in targeted therapy and a marker for cancer behavior and prognosis.

Yang XH, Wang B, Cunningham JM
Identification of epigenetic modifications that contribute to pathogenesis in therapy-related AML: Effective integration of genome-wide histone modification with transcriptional profiles.
BMC Med Genomics. 2015; 8 Suppl 2:S6 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Therapy-related, secondary acute myeloid leukemia (t-AML) is an increasingly frequent complication of intensive chemotherapy. This malignancy is often characterized by abnormalities of chromosome 7, including large deletions or chromosomal loss. A variety of studies suggest that decreased expression of the EZH2 gene located at 7q36.1 is critical in disease pathogenesis. This histone methyltransferase has been implicated in transcriptional repression through modifying histone H3 on lysine 27 (H3k27). However, the critical target genes of EZH2 and their regulatory roles remain unclear.
METHOD: To characterize the subset of EZH2 target genes that might contribute to t-AML pathogenesis, we developed a novel computational analysis to integrate tissue-specific histone modifications and genome-wide transcriptional regulation. Initial integrative analysis utilized a novel "seq2gene" strategy to explore largely the target genes of chromatin immuneprecipitation sequencing (ChIP-seq) enriched regions. By combining seq2gene with our Phenotype-Genotype-Network (PGNet) algorithm, we enriched genes with similar expression profiles and genomic or functional characteristics into "biomodules".
RESULTS: Initial studies identified SEMA3A (semaphoring 3A) as a novel oncogenic candidate that is regulated by EZH2-silencing, using data derived from both normal and leukemic cell lines as well as murine cells deficient in EZH2. A microsatellite marker at the SEMA3A promoter has been associated with chemosensitivity and radiosensitivity. Notably, our subsequent studies in primary t-AML demonstrate an expected up-regulation of SEMA3A that is EZH2-modulated. Furthermore, we have identified three biomodules that are co-expressed with SEMA3A and up-regulated in t-AML, one of which consists of previously characterized EZH2-repressed gene targets. The other two biomodules include MAPK8 and TATA box targets. Together, our studies suggest an important role for EZH2 targets in t-AML pathogenesis that warrants further study.
CONCLUSION: These developed computational algorithms and systems biology strategies will enhance the knowledge discovery and hypothesis-driven analysis of multiple next generation sequencing data, for t-AML and other complex diseases.

Jiang H, Qi L, Wang F, et al.
Decreased semaphorin 3A expression is associated with a poor prognosis in patients with epithelial ovarian carcinoma.
Int J Mol Med. 2015; 35(5):1374-80 [PubMed] Related Publications
Semaphorin 3A (SEMA3A) was initially identified to play an important role in axonal guidance. Recently, SEMA3A has also been considered as a candidate tumor suppressor, since it is often downregulated in numerous types of cancer, including prostate cancer, breast cancer and glioma. However, the biological role of SEMA3A in ovarian cancer is not clear. In the present study, the expression of SEMA3A in ovarian cancer and normal ovarian epithelial tissues was detected by immunofluorescence, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blotting, and the associations between the expression of SEMA3A with the development of ovarian cancer, clinicopathological characteristics and survival were also analyzed. Results from immunofluorescence, RT‑qPCR and western blotting showed that SEMA3A is significantly downregulated in epithelial ovarian carcinoma compared to normal ovarian epithelial specimens (P<0.05). The expression levels of SEMA3A were lower in the cancer tissues with III/IV stage [the International Federation of Gynecology and Obstetrics (FIGO) stage], poor histological grade, lymph node metastasis and distant metastasis compared to that in the cancer tissues with I/II stage (FIGO), well histological grade, or without lymph node metastasis and distant metastasis (P<0.05). A decreased expression of SEMA3A is associated with a poor prognosis (P<0.001). The present findings suggest that decreased SEMA3A expression may be associated with the development of epithelial ovarian carcinoma, and therefore, SEMA3A may be a valuable prognostic marker, as well as a potential molecular therapy target for ovarian cancer patients.

Shostak K, Zhang X, Hubert P, et al.
NF-κB-induced KIAA1199 promotes survival through EGFR signalling.
Nat Commun. 2014; 5:5232 [PubMed] Free Access to Full Article Related Publications
Constitutive activation of EGFR- and NF-κB-dependent pathways is a hallmark of cancer, yet signalling proteins that connect both oncogenic cascades are poorly characterized. Here we define KIAA1199 as a BCL-3- and p65-dependent gene in transformed keratinocytes. KIAA1199 expression is enhanced on human papillomavirus (HPV) infection and is aberrantly expressed in clinical cases of cervical (pre)neoplastic lesions. Mechanistically, KIAA1199 binds Plexin A2 and protects from Semaphorin 3A-mediated cell death by promoting EGFR stability and signalling. Moreover, KIAA1199 is an EGFR-binding protein and KIAA1199 deficiency impairs EGF-dependent Src, MEK1 and ERK1/2 phosphorylations. Therefore, EGFR stability and signalling to downstream kinases requires KIAA1199. As such, KIAA1199 promotes EGF-mediated epithelial-mesenchymal transition (EMT). Taken together, our data define KIAA1199 as an oncogenic protein induced by HPV infection and constitutive NF-κB activity that transmits pro-survival and invasive signals through EGFR signalling.

Ruan SS, Li RC, Han Q, et al.
Expression and clinical significance of Semaphorin4D in non-small cell lung cancer and its impact on malignant behaviors of A549 lung cancer cells.
J Huazhong Univ Sci Technolog Med Sci. 2014; 34(4):491-496 [PubMed] Related Publications
This study aimed to explore Semaphrin4D (Sema4D) expression and clinical significance in non-small cell lung cancer (NSCLC), and to define the roles and mechanisms of Sema4D in regulating the malignant behaviors of A549 cells by small interfering RNA (siRNA). Firstly, immunohistochemistry revealed that Sema4D was more frequently expressed in NSCLC than in lung benign lesion (P<0.05) and its overexpression was associated with low differentiation (P<0.05), poor pTNM staging (P<0.05) and occurrence of lymph node (LN) metastasis (P<0.05). Endogenous Sema4D expression was suppressed by Sema4D siRNA in A549 cells overexpressing Sema4D. Protein levels of Sema4D, total Akt and p-Akt were examined by Western blotting. Cell proliferation, migration and invasion abilities were measured by MTT assay and Transwell assay respectively. Results showed that Sema4D siRNA significantly suppressed phosphorylation of AKT in A549 cells, but it did not alter total AKT expression. In addition, efficient down-regulation of SemaD significantly inhibit cell proliferation (P<0.05), migration (P<0.05) and invasion (P<0.05) in A549 cells. These findings suggest that Sema4D might serve as a reliable tool for early prediction of NSCLC poor prognosis. Sema4D could play an important role in promoting tumor proliferation, migration and metastasis in the NSCLC, by influencing the Akt protein phosphorylation. Inhibition of Sema4D may be a useful approach for the treatment of NSCLC.

Mishra R, Thorat D, Soundararajan G, et al.
Semaphorin 3A upregulates FOXO 3a-dependent MelCAM expression leading to attenuation of breast tumor growth and angiogenesis.
Oncogene. 2015; 34(12):1584-95 [PubMed] Related Publications
Semaphorin 3A (Sema 3A), a member of semaphorin family, serves as a guidance clue during embryonic development and is known as a candidate tumor suppressor that attenuates breast tumor progression by binding with its co-receptor, neuropilin-1 (NRP-1). However, the underlying mechanism by which Sema 3A suppresses breast tumor growth is still unexplored. In this study, we report that Sema 3A regulates phosphorylation and nuclear translocation of phosphatase and tensin homolog (PTEN) and FOXO 3a. Moreover, Sema 3A controls NRP-1-mediated PTEN-dependent FOXO 3a activation. Overexpression of PTEN and FOXO 3a enhances Sema 3A-induced attenuation of breast cancer cell migration. Chromatin immunoprecipitation and electrophoretic mobility shift assay data revealed that FOXO 3a regulates MelCAM at the transcriptional level. Furthermore, Sema 3A induces NRP-1-mediated MelCAM expression through PTEN and FOXO 3a. The data also showed that vascular endothelial growth factor-induced angiogenesis is inhibited by Sema 3A. Loss of or gain in function study revealed that Sema 3A modulates phosphorylation of PTEN and FOXO 3a and expression of MelCAM, leading to suppression of tumor growth and angiogenesis using in vivo mice model. Clinical specimen analysis revealed that reduced expression of Sema 3A and p-PTEN are correlated with enhanced breast cancer progression, further strengthening our in vitro and in vivo findings. Correlation of relapse-free survival of breast cancer patients (n=2878) with expression levels of Sema 3A, NRP-1, FOXO 3a and MelCAM were studied by Kaplan-Meier analysis. Statistical analysis revealed a close association between reduced expression of Sema 3A and MelCAM with that of poor patient's survival. Our study demonstrated a novel mechanism of regulation of tumor suppression by Sema 3A in coordination with a chain of tumor-suppressor genes, which in turn inhibits breast cancer cell migration, tumor growth and angiogenesis.

Deng BY, Hua YQ, Cai ZD
Establishing an osteosarcoma associated protein-protein interaction network to explore the pathogenesis of osteosarcoma.
Eur J Med Res. 2013; 18:57 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The aim of this study was to establish an osteosarcoma (OS) associated protein-protein interaction network and explore the pathogenesis of osteosarcoma.
METHODS: The gene expression profile GSE9508 was downloaded from the Gene Expression Omnibus database, including five samples of non-malignant bone (the control), seven samples for non-metastatic patients (six of which were analyzed in duplicate), and 11 samples for metastatic patients (10 of which were analyzed in duplicate). Differentially expressed genes (DEGs) between osteosarcoma and control samples were identified by packages in R with the threshold of |logFC (fold change)| > 1 and false discovery rate < 0.05. Osprey software was used to construct the interaction network of DEGs, and genes at protein-protein interaction (PPI) nodes with high degrees were identified. The Database for Annotation, Visualization and Integrated Discovery and WebGestalt software were then used to perform functional annotation and pathway enrichment analyses for PPI networks, in which P < 0.05 was considered statistically significant.
RESULTS: Compared to the control samples, the expressions of 42 and 341 genes were altered in non-metastatic OS and metastatic OS samples, respectively. A total of 15 significantly enriched functions were obtained with Gene Ontology analysis (P < 0.05). The DEGs were classified and significantly enriched in three pathways, including the tricarboxylic acid cycle, lysosome and axon guidance. Genes such as HRAS, IDH3A, ATP6ap1, ATP6V0D2, SEMA3F and SEMA3A were involved in the enriched pathways.
CONCLUSIONS: The hub genes from metastatic OS samples are not only bio-markers of OS, but also help to improve therapies for OS.

Rosenberg EE, Prudnikova TY, Zabarovsky ER, et al.
D-glucuronyl C5-epimerase cell type specifically affects angiogenesis pathway in different prostate cancer cells.
Tumour Biol. 2014; 35(4):3237-45 [PubMed] Related Publications
D-glucuronyl C5-epimerase (GLCE) is involved in breast and lung carcinogenesis as a potential tumor suppressor gene, acting through inhibition of tumor angiogenesis and invasion/metastasis pathways. However, in prostate tumors, increased GLCE expression is associated with advanced disease, suggesting versatile effects of GLCE in different cancers. To investigate further the potential cancer-promoting effect of GLCE in prostate cancer, GLCE was ectopically re-expressed in morphologically different LNCaP and PC3 prostate cancer cells. Transcriptional profiles of normal PNT2 prostate cells, LNCaP, PC3 and DU145 prostate cancer cells, and GLCE-expressing LNCaP and PC3 cells were determined. Comparative analysis revealed the genes whose expression was changed in prostate cancer cells compared with normal PNT2 cells, and those differently expressed between the cancer cell lines (ACTA2, IL6, SERPINE1, TAGLN, SEMA3A, and CDH2). GLCE re-expression influenced mainly angiogenesis-involved genes (ANGPT1, SERPINE1, IGF1, PDGFB, TNF, IL8, TEK, IFNA1, and IFNB1) but in a cell type-specific manner (from basic deregulation of angiogenesis in LNCaP cells to significant activation in PC3 cells). Invasion/metastasis pathway was also affected (MMP1, MMP2, MMP9, S100A4, ITGA1, ITGB3, ERBB2, and FAS). The obtained results suggest activation of angiogenesis as a main molecular mechanism of pro-oncogenic effect of GLCE in prostate cancer. GLCE up-regulation plus expression pattern of a panel of six genes, discriminating morphologically different prostate cancer cell sub-types, is suggested as a potential marker of aggressive prostate cancer.

Nassehi D
Intracranial meningiomas, the VEGF-A pathway, and peritumoral brain oedema.
Dan Med J. 2013; 60(4):B4626 [PubMed] Related Publications
Meningiomas are the second-most common intracranial tumours in adults. They are derived from the arachnoid cells, and although approximately 90% of meningiomas are benign, more than half of all meningiomas develop peritumoral brain oedema (PTBE), which increases morbidity. The PTBE can be treated with steroid therapy, but this treatment is not specific, is not always effective, and involves long-term side-effects. Meningiomas are treated with radiation therapy, stereotactic radio-surgery or surgical resection. At the moment surgical resection is the only definite treatment, and the removal of the tumour also removes the PTBE. Based on the localization of the meningioma, surgery can be complicated. Although PTBE around meningiomas is frequent, the mechanisms behind its development are not clearly understood. It is believed that due to tumour growth and local tissue hypoxia, angiogenesis is increased and leads to the formation of PTBE. The angiogenic protein vascular endothelial growth factor A (VEGF-A) is believed to be involved in the formation of PTBE around meningiomas, as several studies have found that it is increased in meningiomas with PTBE. VEGF-A is also known as vascular permeability factor due to its ability to increase the permeability of capillaries. Paper I examines the VEGF-A protein and mRNA levels in 101 intracranial meningiomas. The PTBE is quantified on MRI, and capillary length and tumour water content are measured and compared to control brain tissue. Possible co-factors to PTBE like meningioma localization and subtypes are also examined. Forty-three of the patients have primary, solitary, supratentorial meningiomas with PTBE. The correlation between PTBE or edema index with the VEGF-A protein and mRNA, capillary length, and tumour water content is investigated in these patients. A novel method is used for mRNA quantification. It involves direct amplification of the mRNA with probes and branched DNA in order to produce a chemiluminescence signal that can be measured using a luminometer. The paper shows that the oedema index is correlated to the VEGF-A protein and mRNA, and that capillary length is correlated to the PTBE. It also finds that VEGF-A protein and mRNA, capillary length and water content is increased in meningiomas compared to control tissue, suggesting that VEGF-A is produced in, and possibly secreted from the meningiomas. In addition, supratentorial meningiomas are shown to have larger PTBE compared to infratentorial meningiomas, suggesting that infratentorial meningiomas are diagnosed and removed earlier, due to earlier symptom development based on the anatomical features of the fossa posterior. Finally, a gender-specific difference in tumour water content and VEGF-A protein is revealed (higher and lower in females, respectively). Paper II is a method-comparison study pitting the chemiluminescence assay against the often used quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR) assay. In RT-qPCR, RNA is isolated, measured, reverse transcribed, purified, amplified via real-time PCR, and analyzed. The method is robust and reliable, albeit laborious to some extent. The chemiluminescence assay detects RNA directly without the need for RNA purification, complement DNA synthesis or cyclic amplification. By comparing the output of the two protocols to a dilution series ranging from 1 to 128 times of the homogenized samples, the precision of the protocols is measured. Furthermore, VEGF-A/GAPDH ratios are quantified for 15 tissue samples and the results compared between the two protocols, showing significant correlation. The study finds that the chemiluminescence assay is competitive to RT-qPCR, and reflects a similar pattern in gene expression measurement with a similar precision. Whether one method or the other should be used depends on the variability of the samples, budget, and time. RT-qPCR has a much wider dynamic range, and is preferable in case of significant sample inter-variability. It is also less expensive, and gives the user more flexibility as homemade reagents can be used. On the other hand, the chemiluminescence assay is straight forward, requires less hands-on-time, and can be used on formalin-fixed and paraffin-embedded (FFPE) tissue. Paper III continues the investigations in paper I. The sample size is increased so that 22 angiomatous and secretory meningiomas are compared to 40 non-angiomatous meningiomas and 10 control brain tissue samples. Angiomatous and secretory meningiomas are chosen because they are known to have larger PTBE compared to other meningiomas. In addition to VEGF-A, capillary length, and PTBE, the VEGF-A tyrosine kinase receptor VEGFR-2 mRNA and protein levels are also examined. VEGFR-2 is a transmembrane receptor found on endothelial cells. It binds VEGF-A and thereby increases angiogenesis. VEGFR-2's co-receptor neuropilin-1 is also examined. Neuropilin-1 is an agonist of angiogenesis through complex-binding of VEGF-A, but it can also work as an inhibitor through competitive binding of semaphorin-3A. The complex binding of semaphorin-3A to neuropilin-1 can also induce endothelial cell apoptosis, thus working as an antagonist of angiogenesis. The study finds that VEGF-A mRNA, VEGF-A protein, and neuropilin-1 mRNA are higher in angiomatous and non-angiomatous meningiomas compared to controls. VEGFR-2 protein is higher, and neuropilin-1 protein lower in angiomatous meningiomas compared to controls. The mean capillary length is 3614 mm/mm3 in angiomatous, 605 mm/mm3 in non-angiomatous meningiomas, and 229 mm/mm3 in the controls. Non-angiomatous and angiomatous meningioma patients have equally sized tumours. The mean PTBE around the angiomatous meningiomas is 695 cm3, i.e. 477 cm3 larger than the non-angiomatous meningiomas (p = 0.0045), and the mean oedema index is twice the size compared to the non-angiomatous meningiomas. Further comparison between the two meningioma groups shows that mean VEGF-A mRNA, VEGFR-2 protein, and neuropilin-1 mRNA is significantly higher and neuropilin-1 protein is lower in the angiomatous meningiomas. We believe that the VEGF-A pathway participates in the formation of PTBE in meningiomas by inducing formation of "leaky" capillaries, resulting in secretion of VEGF-A and plasma to the peritumoural brain tissue. It may therefore be worth pursuing therapies targeted directly against VEGF-A and its receptors through drugs like bevacizumab, sorafenib, sunitifib, and cediranib.

Carrer A, Moimas S, Zacchigna S, et al.
Neuropilin-1 identifies a subset of bone marrow Gr1- monocytes that can induce tumor vessel normalization and inhibit tumor growth.
Cancer Res. 2012; 72(24):6371-81 [PubMed] Related Publications
Improving tumor perfusion, thus tempering tumor-associated hypoxia, is known to impair cancer progression. Previous work from our laboratory has shown that VEGF-A165 and semaphorin 3A (Sema3A) promote vessel maturation through the recruitment of a population of circulating monocytes expressing the neuropilin-1 (Nrp1) receptor (Nrp1-expressing monocytes; NEM). Here, we define the characteristics of bone marrow NEMs and assess whether these cells might represent an exploitable tool to induce tumor vessel maturation. Gene expression signature and surface marker analysis have indicated that NEMs represent a specific subset of CD11b+ Nrp1+ Gr1- resident monocytes, distinctively recruited by Sema3A. NEMs were found to produce several factors involved in vessel maturation, including PDGFb, TGF-β, thrombospondin-1, and CXCL10; consistently, they were chemoattractive for vascular smooth muscle cells in vitro. When directly injected into growing tumors, NEMs, isolated either from the bone marrow or from Sema3A-expressing muscles, exerted antitumor activity despite having no direct effects on the proliferation of tumor cells. NEM inoculation specifically promoted mural cell coverage of tumor vessels and decreased vascular leakiness. Tumors treated with NEMs were smaller, better perfused and less hypoxic, and had a reduced level of activation of HIF-1α. We conclude that NEMs represent a novel, unique population of myeloid cells that, once inoculated into a tumor, induce tumor vessel normalization and inhibit tumor growth.

Zhou X, Ma L, Li J, et al.
Effects of SEMA3G on migration and invasion of glioma cells.
Oncol Rep. 2012; 28(1):269-75 [PubMed] Related Publications
Glioblastoma multiforme is the most aggressive type of brain tumor with a strong ability to invade and migrate into surrounding normal brain tissues, leading to high tumor recurrence and mortality. Most of class-3 semaphorins, especially SEMA3A, SEMA3B and SEMA3F, have been reported to have strong tumor inhibition ability, but the role of SEMA3G in tumor biology is largely unknown. We report here that SEMA3G possesses anti-migration and anti-invasion ability. To determine the potential effects of SEMA3G on migratory and invasive ability, we generated stable SEMA3G expression U251MG cells. We found that stably overexpressed SEMA3G inhibited the migratory and invasive behavior of U251MG cells. In addition, treatment with SEMA3G conditioned media also decreased the migratory and invasive ability of parental U251MG cells. Furthermore, SEMA3G also inhibited the activity of MMP2, an index of tumor invasion ability. Thus, our results suggest that SEMA3G inhibited tumor cell migration and invasion, which may be obtained through cell autonomous or paracrine mechanisms, and SEMA3G is a potential target for antitumor migration and invasion.

Agesen TH, Sveen A, Merok MA, et al.
ColoGuideEx: a robust gene classifier specific for stage II colorectal cancer prognosis.
Gut. 2012; 61(11):1560-7 [PubMed] Related Publications
BACKGROUND AND AIMS: Several clinical factors have an impact on prognosis in stage II colorectal cancer (CRC), but as yet they are inadequate for risk assessment. The present study aimed to develop a gene expression classifier for improved risk stratification of patients with stage II CRC.
METHODS: 315 CRC samples were included in the study. Gene expression measurements from 207 CRC samples (stage I-IV) from two independent Norwegian clinical series were obtained using Affymetrix exon-level microarrays. Differentially expressed genes between stage I and stage IV samples from the test series were identified and used as input for L1 (lasso) penalised Cox proportional hazards analyses of patients with stage II CRC from the same series. A second validation was performed in 108 stage II CRC samples from other populations (USA and Australia).
RESULTS: An optimal 13-gene expression classifier (PIGR, CXCL13, MMP3, TUBA1B, SESN1, AZGP1, KLK6, EPHA7, SEMA3A, DSC3, CXCL10, ENPP3, BNIP3) for prediction of relapse among patients with stage II CRC was developed using a consecutive Norwegian test series from patients treated according to current standard protocols (n=44, p<0.001, HR=18.2), and its predictive value was successfully validated for patients with stage II CRC in a second Norwegian CRC series collected two decades previously (n=52, p=0.02, HR=3.6). Further validation of the classifier was obtained in a recent external dataset of patients with stage II CRC from other populations (n=108, p=0.001, HR=6.5). Multivariate Cox regression analyses, including all three sample series and various clinicopathological variables, confirmed the independent prognostic value of the classifier (p≤0.004). The classifier was shown to be specific to stage II CRC and does not provide prognostic stratification of patients with stage III CRC.
CONCLUSION: This study presents the development and validation of a 13-gene expression classifier, ColoGuideEx, for prognosis prediction specific to patients with stage II CRC. The robustness was shown across patient series, populations and different microarray versions.

Yoshikawa Y, Sato A, Tsujimura T, et al.
Frequent deletion of 3p21.1 region carrying semaphorin 3G and aberrant expression of the genes participating in semaphorin signaling in the epithelioid type of malignant mesothelioma cells.
Int J Oncol. 2011; 39(6):1365-74 [PubMed] Related Publications
Array-based comparative genomic hybridization analysis was performed on 21 malignant mesothelioma (MM) samples (16 primary cell cultures and 5 cell lines) and two reactive mesothelial hyperplasia (RM) primary cell cultures. The RM samples did not have any genomic losses or gains. In MM samples, deletions in 1p, 3p21, 4q, 9p21, 16p13 and 22q were detected frequently. We focused on 3p21 because this deletion was specific to the epithelioid type. Especially, a deletion in 3p21.1 region carrying seven genes including SEMA3G was found in 52% of MM samples (11 of 14 epithelioid samples). The allele loss of 3p21.1 might be a good marker for the epithelioid MM. A homozygous deletion in this region was detected in two MM primary cell cultures. A heterozygous deletion detected in nine samples contained the 3p21.1 region and 3p21.31 one carrying the candidate tumor suppressor genes such as semaphorin 3F (SEMA3F), SEMA3B and Ras association (RalGDS/AF-6) domain family member 1 (RASSF1A). SEMA3B, 3F and 3G are class 3 semaphorins and inhibit growth by competing with vascular endothelial growth factor (VEGF) through binding to neuropilin. All MM samples downregulated the expression of more than one gene for SEMA3B, 3F and 3G when compared with Met5a, a normal pleura-derived cell line. Moreover, in 12 of 14 epithelioid MM samples the expression level of SEMA3A was lower than that in Met5a and the two RM samples. An augmented expression of VEGFA was detected in half of the MM samples. The expression ratio of VEGFA/SEMA3A was significantly higher in the epithelioid MMs than in Met5a, RMs and the non-epithelioid MMs. Our data suggest that the downregulated expression of SEMA3A and several SEMA3s results in a loss of inhibitory activities in tumor angiogenesis and tumor growth of VEGFA; therefore, it may play an important role on the pathogenesis of the epithelioid type of MM.

Larsson M, Duffy DL, Zhu G, et al.
GWAS findings for human iris patterns: associations with variants in genes that influence normal neuronal pattern development.
Am J Hum Genet. 2011; 89(2):334-43 [PubMed] Free Access to Full Article Related Publications
Human iris patterns are highly variable. The origins of this variation are of interest in the study of iris-related eye diseases and forensics, as well as from an embryological developmental perspective, with regard to their possible relationship to fundamental processes of neurodevelopment. We have performed genome-wide association scans on four iris characteristics (crypt frequency, furrow contractions, presence of peripupillary pigmented ring, and number of nevi) in three Australian samples of European descent. Both the discovery (n = 2121) and replication (n = 499 and 73) samples showed evidence for association between (1) crypt frequency and variants in the axonal guidance gene SEMA3A (p = 6.6 × 10(-11)), (2) furrow contractions and variants within the cytoskeleton gene TRAF3IP1 (p = 2.3 × 10(-12)), and (3) the pigmented ring and variants in the well-known pigmentation gene SLC24A4 (p = 7.6 × 10(-21)). These replicated findings individually accounted for around 1.5%-3% of the variance for these iris characteristics. Because both SEMA3A and TRAFIP1 are implicated in pathways that control neurogenesis, neural migration, and synaptogenesis, we also examined the evidence of enhancement among such genes, finding enrichment for crypts and furrows. These findings suggest that genes involved in normal neuronal pattern development may also influence tissue structures in the human iris.

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