Vascular endothelial growth inhibitor (VEGI; TNFSF15) inhibits bone marrow-derived endothelial progenitor cell incorporation into Lewis lung carcinoma tumors

Angiogenic and anti-angiogenic factors during the post-hatching growth of the quail (Coturnix coturnix japonica) spleen

Vascular endothelial growth factor (VEGF) family members are responsible for endothelial cells' growth, proliferation, migration, angiogenesis, vascular permeability, and differentiation and proliferation of non-endothelial cell types. VEGF and its receptors are found in mammalian lymphoid organs. The present study was conceived to determine (a) the presence and localization of angiogenic VEGF and its receptors (Fms-like tyrosine kinase 1 [Flt1/fms], fetal liver kinase 1 [Flk1]/kinase insert domain receptor [KDR], Fms-like tyrosine kinase 4 [Flt4]) and vascular endothelial growth inhibitor (VEGI) in the quail spleen; and (b) whether their expressions in the spleen components change during the post-hatching growth of the organ, using immunohistochemistry. Immunohistochemical stainings showed that VEGI, VEGF, and VEGF receptors were expressed in many components, including the vascular endothelial and smooth muscle cells, ellipsoid-associated cells (EACs), and immune cells, of quail spleen and that VEGF and its receptors' immunostaining intensity scores (ISs) varied depending on the post-hatching growth period, while VEGI-IS did not change. In addition, ISs of VEGI, VEGF, Flt1/fms, and Flt4 in EACs were weak to moderate, while flk1/KDR-IS in EACs adjacent to the capsule of Schweigger-Seidel sheaths (ellipsoids) was higher than other proteins, supports a more important and specific role of Flk1/KDR in the EAC function. These specific expressions of VEGI, VEGF, flt1/fms, flk1/KDR, and flt4 proteins in splenic cell types suggest their particular roles, in the functional development of splenic components and thus, are critical to post-hatching maturation of quail spleen. These findings indicate that the expression levels of VEGF, Flt1/fms, and Flt4, except Flk1/KDR, are low in the quail spleen, and only a few components of the spleen express VEGF, Flt1/fms, and Flt4 under normal conditions.

The genomic landscape of the immune system in lung cancer: present insights and continuing investigations

Lung cancer is one of the most prevalent malignancies worldwide, contributing to over a million cancer-related deaths annually. Despite extensive research investigating the genetic factors associated with lung cancer susceptibility and prognosis, few studies have explored genetic predispositions regarding the immune system. This review discusses the most recent genomic findings related to the susceptibility to or protection against lung cancer, patient survival, and therapeutic responses. The results demonstrated the effect of immunogenetic variations in immune system-related genes associated with innate and adaptive immune responses, cytokine, and chemokine secretions, and signaling pathways. These genetic diversities may affect the crosstalk between tumor and immune cells within the tumor microenvironment, influencing cancer progression, invasion, and prognosis. Given the considerable variability in the individual immunegenomics profiles, future studies should prioritize large-scale analyses to identify potential genetic variations associated with lung cancer using highthroughput technologies across different populations. This approach will provide further information for predicting response to targeted therapy and promotes the development of new measures for individualized cancer treatment.

TNFSF15 facilitates the differentiation of CD11b+ myeloid cells into vascular pericytes in tumors

OBJECTIVE

Immature vasculature lacking pericyte coverage substantially contributes to tumor growth, drug resistance, and cancer cell dissemination. We previously demonstrated that tumor necrosis factor superfamily 15 (TNFSF15) is a cytokine with important roles in modulating hematopoiesis and vascular homeostasis. The main purpose of this study was to explore whether TNFSF15 might promote freshly isolated myeloid cells to differentiate into CD11b+ cells and further into pericytes.

METHODS

A model of Lewis lung cancer was established in mice with red fluorescent bone marrow. After TNFSF15 treatment, CD11b+ myeloid cells and vascular pericytes in the tumors, and the co-localization of pericytes and vascular endothelial cells, were assessed. Additionally, CD11b+ cells were isolated from wild-type mice and treated with TNFSF15 to determine the effects on the differentiation of these cells.

RESULTS

We observed elevated percentages of bone marrow-derived CD11b+ myeloid cells and vascular pericytes in TNFSF15-treated tumors, and the latter cells co-localized with vascular endothelial cells. TNFSF15 protected against CD11b+ cell apoptosis and facilitated the differentiation of these cells into pericytes by down-regulating Wnt3a-VEGFR1 and up-regulating CD49e-FN signaling pathways.

CONCLUSIONS

TNFSF15 facilitates the production of CD11b+ cells in the bone marrow and promotes the differentiation of these cells into pericytes, which may stabilize the tumor neovasculature.

Immune Checkpoint Inhibitor (ICI) Genes and Aging in Clear Cell Renal Cell Carcinoma (ccRCC): Clinical and Genomic Study

Background: It is anticipated that there will be a large rise in the number of tumor diagnoses and mortality in those aged 65 and older over the course of upcoming decades. Immune checkpoint inhibitors, often known as ICIs, boost immune system activity by selectively targeting ICI genes. On the other hand, old age may be connected with unfavorable results. Methods: The Cancer Genome Atlas (TCGA) provided gene expression data from ccRCC tissue and key clinical variables. ICI gene databases were applied and verified using the GEO database. Results: We identified 14 ICI genes as risk gene signatures among 528 ccRCC patients using univariate and multivariable cox hazard models, and the elderly group was linked with poor survival. Then, by utilizing a new nomogram method, the TNFSF15 gene and age predicting values were estimated at one, three, and five years (85%, 81%, and 81%), respectively, and our age-related risk score was significant even after multivariable analysis (HR = 1.518, p = 0.009, CI = 1.1102.076). TNFSF15 gene expression was lower in elderly ccRCC patients (p = 0.0001). A negative connection between age and the TNFSF15 gene expression was discovered by correlation analysis (p = 0.0001). The verification of the gene by utilizing GEO (GSE167093) with 604 patients was obtained as external validation that showed significant differences in the TNFSF15 gene between young and elderly patients (p = 0.007). Additionally, the protein-protein interactions of the TNFSF15 gene with other ICI genes and aging-related genes was determined. In addition, the TNFSF15 expression was significantly correlated with pathological stages (p = 0.018). Furthermore, it was discovered that the biological processes of senescence, cellular senescence, the immune system, and many immune cell infiltration and immune function types are all closely tied. Conclusions: Along with the risk score evaluation, the ICI gene TNFSF15 was identified as a tumor suppressor gene related to inequalities in age survival and is associated with pathological stages and different immunity statuses. The aging responses of ccRCC patients and related gene expression need further investigation in order to identify potential therapeutic targets.

Tumor necrosis factor ligand-related molecule 1A maintains blood-retinal barrier via modulating SHP-1-Src-VE-cadherin signaling in diabetic retinopathy

An impaired blood-retinal barrier (BRB) leads to diabetic macular edema (DME), which is a major complication of Diabetic retinopathy (DR). Mediators such as inflammation cause BRB breakdown. However, the explicit mechanism of its disruption is largely unknown. In this study, we identified tumor necrosis factor ligand-related molecule 1A (TL1A) as a crucial factor which protect retinal endothelial cells integrity in DR. By providing both human and mouse data, we show that TL1A is significantly decreased in the retinas of DME patients and diabetic rodents. We further demonstrate that the loss of TL1A accelerated diabetes-induced retinal barrier breakdown. TL1A supplementation protects the diabetic retina against BRB breakdown. Mechanistically, TL1A stabilize intracellular junctions and protect vascular integrity by blocking SHP1-Src-regulated VE-cadherin phosphorylation. Collectively, our findings reveal that loss of TL1A in the retina leads to increased vascular permeability in DR, and that TL1A treatment is of potential therapeutic interest for the treatment of DME.

VEGI downregulation is correlated with nodal metastasis and poor prognosis in lung adenocarcinoma

Although the incidence of lung cancer is increasing worldwide, the molecular mechanisms for its tumorigenesis, progression and prognosis remain unknown. As a member of the tumor necrosis factor superfamily, vascular endothelial growth inhibitor (VEGI) is involved in the development and progression of many malignant diseases. In the present study, the expression of VEGI and CD31 was examined via immunohistochemistry in non-small cell lung cancer (NSCLC) tissues obtained from 150 patients with NSCLC. The inhibitory effect of VEGI on tumor-associated blood vessel formation and growth was investigated by determining the relationship between VEGI protein expression and microvascular density (MVD). Prognostic significance was evaluated using the Kaplan-Meier method. VEGI expression was downregulated or lost in 68.7% (103/150) of patients with NSCLC, an effect that was more prevalent in adenocarcinoma (AC), 76.0% (57/75), than in squamous cell carcinoma, 61.3% (46/75). A significant negative correlation was indentified between VEGI expression and lymphovascular invasion (P=0.039) and lymph node metastasis (P=0.017) in AC tissue. Additionally, MVD was significantly lower in the VEGI-rich group compared with the VEGI-poor group. The downregulation of VEGI expression was also associated with poorer overall survival (P=0.011) in patients with AC. The present study therefore provides evidence that VEGI may be a new and effective prognostic marker of lung AC.

TNFSF15 facilitates human umbilical cord blood haematopoietic stem cell expansion by activating Notch signal pathway

The lack of efficient ex vivo expansion methods restricts clinical use of haematopoietic stem cells (HSC) for the treatment of haematological malignancies and degenerative diseases. Umbilical cord blood (UCB) serves as an alternative haematopoietic stem cell source. However, currently what limits the use of UCB‐derived HSC is the very low numbers of haematopoietic stem and progenitor cells available for transplantation in a single umbilical cord blood unit. Here, we report that TNFSF15, a member of the tumour necrosis factor superfamily, promotes the expansion of human umbilical cord blood (UCB)‐derived HSC. TNFSF15‐treated UCB‐HSC is capable of bone marrow engraftment as demonstrated with NOD/SCID or NOD/Shi‐SCID/IL2Rgnull (NOG) mice in both primary and secondary transplantation. The frequency of repopulating cells occurring in the injected tibiae is markedly higher than that in vehicle‐treated group. Additionally, signal proteins of the Notch pathway are highly up‐regulated in TNFSF15‐treated UCB‐HSC. These findings indicate that TNFSF15 is useful for in vitro expansion of UCB‐HSC for clinical applications. Furthermore, TNFSF15 may be a hopeful selection for further UCB‐HSC application or study.

Intraocular tumour necrosis factor ligand related molecule 1 A links disease progression of proliferative diabetic retinopathy after primary vitrectomy

Tumour necrosis factor ligand related molecule 1 A (TL1A), a member of tumour necrosis factor superfamily, has been identified as a crucial regulator for vascular homeostasis and inflammation. However, the function of TL1A in diabetic retinopathy (DR) is largely unknown. This study aims to examine levels of TL1A in serum and intraocular fluid in patients with proliferative diabetic retinopathy (PDR), and to explore the correlation of intraocular TL1A with the prognosis of PDR progression after primary vitrectomy. Seventy-five patients (75 eyes) with PDR who underwent pars plana vitrectomy (PPV) and 19 patients (19 eyes) who received vitrectomy for idiopathic macular holes (IMH) as non-diabetic control group were enrolled in this prospective study. Serum, aqueous and vitreous fluid samples were collected during cataract and PPV surgery. Protein expressions of TL1A as well as other angiogenic and inflammatory cytokines in serum and intraocular fluid were measured. Correlations of intraocular TL1A concentrations with inflammatory cytokines were analyzed. We found both aqueous and vitreous TL1A levels were significantly higher in the PDR group than in control group (P_aqueous  = 0.026; P_vitreous <0.001). Angiogenic and inflammatory cytokines such as VEGF, IL-6, IL-8, MCP-1, MIP-1α, and MIP-1β were significantly higher in intraocular fluid in PDR group than in controls, which MCP-1 and MIP-1α showed positive correlation with intraocular TL1A levels. There is no significant difference in the levels of serum TL1A as well as other inflammatory cytokines between PDR patients and controls. Intraocular levels of TL1A were significantly lower in PDR progression group than in the stable group (P_aqueous <0.001; P_vitreous <0.001). Multivariate logistic regression analyses revealed that lower levels of intraocular TL1A was an important risk factor for predicting PDR progression after primary PPV (OR_aqueous  = 0.717, P_aqueous  = 0.001; OR_vitreous  = 0.684; P_vitreous  = 0.002). In conclusion, TL1A and multiple inflammatory cytokines were highly enriched in the intraocular fluid of PDR patients compared with the controls. Lower levels of intraocular TL1A were associated with development of PDR complications after primary PPV and might be used as prognostic factor in predicting the vitrectomy outcome in PDR patients.

Vascular Endothelial Growth Inhibitor, a Cytokine of the Tumor Necrosis Factor Family, is Associated With Epithelial-Mesenchymal Transition in Renal Cell Carcinoma

Previous studies have revealed that the activation of the epithelial-mesenchymal transition (EMT) endows metastatic properties upon cancer cells to promote invasion and migration. In this study, immunohistochemical analysis was performed in 50 cases of clear cell renal cell carcinoma (RCC) and paired normal kidney tissues. We detected the expression of vascular endothelial growth inhibitor (VEGI) and EMT markers (E-cadherin, fibronectin, and Slug) and recorded the clinical, pathologic, and follow-up (median follow-up: 79.0 mo) information. The expression of VEGI and E-cadherin was significantly lower in RCC tissues compared with normal kidney tissues (P<0.001). However, the expression of fibronectin and Slug was higher in RCC tissues (P<0.05). VEGI and EMT marker expression marginally differed in tumor size and stage. Significant differences were found in the pathologic grade (P<0.05). The Spearman correlation analysis suggested a positive correlation between VEGI and E-cadherin (r=0.451, P<0.01). A negative correlation was shown between VEGI and fibronectin (r=-0.465, P<0.01). There was also a negative correlation between VEGI and Slug (r=-0.758, P<0.01). During the 79.0 months (range, 7 to 119 mo) of follow-up, 6 patients died due to RCC, and the tumor-free survival rate was 88% (44/50). We did not find a significant correlation between VEGI/EMT markers (E-cadherin, fibronectin, and Slug) and overall survival (P>0.05). Our findings indicate that VEGI plays an important role in EMT in RCC. It suggests that VEGI may be investigated as a disease biomarker and therapeutic target in RCC.

TNFSF15 promoter polymorphisms increase the susceptibility to small cell lung cancer: a case-control study

BACKGROUND

Tumor necrosis factor superfamily member 15 (TNFSF15) is closely related to tumorigenesis and development. This study aimed to investigate the correlations between TNFSF15 polymorphisms and genetic susceptibility to lung cancer.

METHODS

This case-control study included 209 small cell lung cancer patients (SCLC), 340 non- small cell lung cancer patients (NSCLC) and 460 health controls. TNFSF15-638 A > G and - 358 T > C polymorphisms were genotyped by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) analysis. Odds ratio (OR) and 95% confidence interval (95% CI) were estimated by unconditional logistic regression.

RESULTS

Our results showed that subjects carrying the TNFSF15-638GG genotype or -358CC genotype were more likely to develop SCLC (-638GG, OR = 1.84, 95%CI = 1.13-2.99; -358CC, OR = 2.44, 95%CI = 1.46-4.06), but not NSCLC (P > 0.05). In stratified analysis, -638GG genotype was related to SCLC among males (OR = 1.95, 95%CI = 1.09-3.45, P = 0.023) and older patients (OR = 2.93, 95%CI = 1.44-8.68, P = 0.006). However, -358CC genotype was associated with SCLC among females (OR = 8.42, 95%CI = 2.22-31.89, P = 0.002) and older subjects with OR (95%CI) of 11.04 (3.57-34.15) (P < 0.001). Moreover, TNFSF15 -358CC was linked with a higher risk of SCLC among non-smokers (OR = 2.54, 95%CI = 1.20-5.35, P = 0.015) but not among smokers (OR = 1.88, 95%CI = 0.92-3.84, P = 0.086).

CONCLUSION

These findings highlight the importance of TNFSF15 polymorphisms in the development of SCLC.

VEGI174 protein and its functional domain peptides exert antitumour effects on renal cell carcinoma

Vascular endothelial growth inhibitor (VEGI) has been identified as an anti‑angiogenic cytokine. However, the effects of VEGI174 protein, and its functional domain peptides V7 and V8, on renal cell carcinoma (RCC) remain unknown. In the present study, the protein and peptides were biosynthesised as experimental agents. The A498 and 786‑O RCC cell lines, and an established mouse xenograft model, were separately treated with VEGI174, V7 or V8. Cellular functions, including proliferation, migration and invasion, were subsequently detected. Cell migration and invasion were monitored using the xCELLigence system. Furthermore, tumour growth and mouse behaviours, including mobility, appetite and body weight, were assessed. The results demonstrated that VEGI174, V7 and V8 inhibited the proliferation, migration and invasion of A498 and 786‑O cell lines when administered at concentrations of 1 and 100 pM, 10 nM and 1 µM. The inhibitory effects exhibited dose‑ and time‑dependent antitumour activity. Furthermore, VEGI174, V7 and V8 inhibited tumour growth in A498 and 786‑O xenograft mice. In the A498 xenografts, the tumour growth inhibition (TGI) rates in the VEGI174‑, V7‑ and V8‑treated groups were 71, 20 and 31%, respectively. In the 786‑O xenografts, the TGI rates in the VEGI174‑, V7‑ and V8‑treated groups were 34, 26 and 31%, respectively. There was no significant loss in body weight and no cases of mortality were observed for all treated mice. In conclusion, VEGI174, V7 and V8 exhibited potential antitumour effects and were well tolerated in vivo. V7 and V8, as functional domain peptides of the VEGI174 protein, may be studied for the future treatment of RCC.

Counterbalance: modulation of VEGF/VEGFR activities by TNFSF15

Vascular hyperpermeability occurs in angiogenesis and several pathobiological conditions, producing elevated interstitial fluid pressure and lymphangiogenesis. How these closely related events are modulated is a fundamentally important question regarding the maintenance of vascular homeostasis and treatment of disease conditions such as cancer, stroke, and myocardial infarction. Signals mediated by vascular endothelial growth factor receptors, noticeably VEGFR-1, −2, and −3, are centrally involved in the promotion of both blood vessel and lymphatic vessel growth. These signaling pathways are counterbalanced or, in the case of VEGFR3, augmented by signals induced by tumor necrosis factor superfamily-15 (TNFSF15). TNFSF15 can simultaneously downregulate membrane-bound VEGFR1 and upregulate soluble VEGFR1, thus changing VEGF/VEGFR1 signals from pro-angiogenic to anti-angiogenic. In addition, TNFSF15 inhibits VEGF-induced VEGFR2 phosphorylation, thereby curbing VEGFR2-mediated enhancement of vascular permeability. Third, and perhaps more interestingly, TNFSF15 is capable of stimulating VEGFR3 gene expression in lymphatic endothelial cells, thus augmenting VEGF-C/D-VEGFR3-facilitated lymphangiogenesis. We discuss the intertwining relationship between the actions of TNFSF15 and VEGF in this review.

The ability of tumor necrosis factor superfamily-15 (TNFSF15) protein to balance the actions of vascular endothelial growth factors (VEGFs) highlights new therapeutic strategies for the treatment of diseases that disrupt the circulatory system. Gui-Li Yang at the Tianjin Neurological Institute and Lu-Yuan Li at Nankai University describe the mechanisms through which TNFSF15 inhibits blood vessel growth mediated by VEGF receptor-1 (VEGFR1) and counterbalances the increase in vascular permeability mediated by VEGFR2. Interestingly, TNFSF15 enhances the effects of VEGFR3 on the formation of lymphatic vessels by promoting VEGFR3 gene expression in lymphatic endothelial cells. Further research will determine whether TNFSF15′s unique capacity to regulate the properties of both blood and lymph vessels can be harnessed to improve the treatment of conditions such as cancer, stroke, myocardial infarction and lymphoedema.

Trophic and neurotrophic factors in human pituitary adenomas (Review)

The pituitary gland is an organ that functionally connects the hypothalamus with the peripheral organs. The pituitary gland is an important regulator of body homeostasis during development, stress, and other processes. Pituitary adenomas are a group of tumors arising from the pituitary gland: they may be subdivided in functional or non-functional, depending on their hormonal activity. Some trophic and neurotrophic factors seem to play a key role in the development and maintenance of the pituitary function and in the regulation of hypothalamo-pituitary-adrenocortical axis activity. Several lines of evidence suggest that trophic and neurotrophic factors may be involved in pituitary function, thus suggesting a possible role of the trophic and neurotrophic factors in the normal development of pituitary gland and in the progression of pituitary adenomas. Additional studies might be necessary to better explain the biological role of these molecules in the development and progression of this type of tumor. In this review, in light of the available literature, data on the following neurotrophic factors are discussed: ciliary neurotrophic factor (CNTF), transforming growth factors β (TGF‑β), glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF), vascular endothelial growth factor (VEGF), vascular endothelial growth inhibitor (VEGI), fibroblast growth factors (FGFs) and epidermal growth factor (EGF) which influence the proliferation and growth of pituitary adenomas.

Vascular endothelial growth inhibitor 174 and its functional domains inhibit epithelial-mesenchymal transition in renal cell carcinoma cells in vitro

The present study was carried out to investigate the effects of vascular endothelial growth inhibitor 174 (VEGI174) and its functional domains (V7 and V8) on epithelial‑mesenchymal transition (EMT) in renal cell carcinoma (RCC) cells in vitro. The RCC cell lines A498 and 786‑O were used in this study. Based on our preliminary study, we selected full‑length VEGI174 and its functional domains (V7 and V8) as the target genes in this study. Plasmids containing VEGI174, V7 or V8 transgenes were constructed and transfected into A498 and 786‑O cell lines. Cytological activity was tested during cell culture. Quantitative PCR and western blot analysis were performed to determine the expression levels of EMT markers (E‑cadherin, vimentin, β‑catenin and Slug). Overexpression of VEGI174, V7 or V8 did not have a significant influence on cell viability (P>0.05). The mRNA level of E‑cadherin was significantly upregulated, while that of vimentin was downregulated in A498VEGIexp, A498V7exp, A498V8exp, 786‑OVEGIexp, 786‑OV7exp and 786‑OV8exp cells compared with the cells containing the empty plasmid controls (P<0.05). The western blot results showed that changes in protein expression levels were consistent with the changes in mRNA expression. Both the mRNA and protein expression levels of β‑catenin and Slug were downregulated in the A498VEGIexp, A498V7exp, A498V8exp, 786‑OVEGIexp, 786‑OV7exp and 786‑OV8exp cells. In conclusion, overexpression of VEGI174, V7 or V8 inhibited EMT in A498 and 786‑O cells. Notably, V7 and V8 are two effective functional domains of VEGI174 that have the potential to be studied for peptide synthesis and the treatment of RCC.

Vascular endothelial growth factor suppresses TNFSF15 production in endothelial cells by stimulating miR-31 and miR-20a expression via activation of Akt and Erk signals

Tumor necrosis factor superfamily‐15 (TNFSF15; VEGI; TL1A) is a negative modulator of angiogenesis for blood vessel homeostasis and is produced by endothelial cells in a mature vasculature. It is known to be downregulated by vascular endothelial growth factor (VEGF), a major regulator of neovascularization but the mechanism of this interaction is unclear. Here we report that VEGF is able to stimulate the production of two microRNAs, miR‐20a and miR‐31, which directly target the 3′‐UTR of TNFSF15. Additionally, we show that two VEGF‐stimulated cell growth signals, Erk and Akt, are responsible for promoting the expression of miR‐20a and miR‐31. Treatment of human umbilical vein endothelial cells (HUVECs) with Akt inhibitor LY294002 results in diminished miR‐20a and miR‐31 production, while Erk inhibitor U0126 prevented VEGF‐stimulated expression of miR‐20a but not that of miR‐31. Furthermore, inactivation of either Erk or Akt signals restores TNFSF15 gene expression. In an angiogenesis assay, elevated miR‐20a or miR‐31 levels in HUVECs leads to enhancement of capillary‐like tubule formation in vitro, whereas lowered miR‐20a and miR‐31 levels results in an inhibition. These findings are consistent with the view that miR‐20a and miR‐31 mediate VEGF‐induced downregulation of TNFSF15. Targeting these microRNA molecules may therefore provide an effective approach to inhibit angiogenesis.

A case-control study about the association between vascular endothelial growth inhibitor gene polymorphisms and breast cancer risk in female patients in Northeast China

Objective

The inhibition of the neovascularization in tumors is a potential therapeutic target of cancer. Vascular endothelial growth inhibitor (VEGI) is a member of the TNF superfamily which has the ability to suppress the formation of new vessels in tumors. In order to study the association between VEGI gene polymorphisms and breast cancer risk, a case-control study was conducted in Chinese Han women in Northeast China.

Methods

Our study involved 708 female breast cancer patients and 685 healthy volunteers. Four SNPs of VEGI gene were analyzed through the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The association between VEGI gene polymorphisms and breast cancer risk was analyzed in our study. The relation between VEGI gene variants and clinical features of breast cancer including lymph node (LN) metastasis, estrogen receptor (ER), progestrogen receptor (PR), tumor protein 53 (p53), human epidermal growth factor receptor 2 (Her-2) and triple negative (ER-/PR-/Her-2-) status was analyzed as well.

Results

We found that the CT genotype and T allele of rs6478106 were more frequent in patients than in controls. There was also a statistical difference in the distribution of C_rs6478106G_rs4263839 haplotype between patients and controls. In addition, SNP rs6478106 and rs4979462 were related with the Her-2 status.

Conclusions

Our results suggest that VEGI gene variants may be related to the breast cancer risk and the clinical features of breast cancer in Chinese Han women in Northeast China.

EphA1 activation promotes the homing of endothelial progenitor cells to hepatocellular carcinoma for tumor neovascularization through the SDF-1/CXCR4 signaling pathway

BACKGROUND

Endothelial progenitor cells (EPCs) can migrate to the tumor tissue and enhance the angiogenesis of hepatocellular carcinoma (HCC); thus, they are associated with a poor prognosis. However, the specific molecular mechanism underlying the homing of EPCs to the HCC neovasculature remains unrevealed.

METHODS

Co-culture experiments of endothelial progenitor cells with HCC cells with modulation of EphA1 were performed in vitro. Using EPCs as angiogenic promoters by injecting them into HCC xenograft-bearing nude mice via their tail veins to test homing ability of EPCs changed according to different EphA1 level in HCC xenograft.

RESULTS

In this study, we found that the up-regulation of EphA1 expression in HCC cells could affect not only the chemotaxis of EPCs to tumor cells and endothelial cells (ECs) but also the tube formation ability of EPCs in a paracrine fashion. Further, we revealed that the increased expression of EphA1 in HCC cells led to an increased SDF-1 concentration in the tumor microenvironment, which in turn activated the SDF-1/CXCR4 axis and enhanced the recruitment of EPCs to HCC. In addition, the EphA1-activated SDF-1 expression and secretion was partially mediated by the PI3K and mTOR pathways. In vivo experiments demonstrated that blocking EphA1/SDF-1/CXCR4 signaling significantly inhibited the growth of HCC xenografts. Using immunohistochemistry and immunofluorescence assays, we verified that the inhibition of tumor angiogenesis was at least partially caused by the decreased number of EPCs homing to tumor tissue.

CONCLUSIONS

Our findings indicate that targeting the EphA1/SDF-1 signaling pathway might be a therapeutic anti-angiogenesis approach for treating HCC.

Sodium valproate, a histone deacetylase inhibitor, modulates the vascular endothelial growth inhibitor-mediated cell death in human osteosarcoma and vascular endothelial cells

The level of vascular endothelial growth inhibitor (VEGI) has been reported to be negatively associated with neovascularization in malignant tumors. The soluble form of VEGI is a potent anti-angiogenic factor due to its effects in inhibiting endothelial cell proliferation. This inhibition is mediated by death receptor 3 (DR3), which contains a death domain in its cytoplasmic tail capable of inducing apoptosis that can be subsequently blocked by decoy receptor 3 (DcR3). We investigated the effects of sodium valproate (VPA) and trichostatin A (TSA), histone deacetylase inhibitors, on the expression of VEGI and its related receptors in human osteosarcoma (OS) cell lines and human microvascular endothelial (HMVE) cells. Consequently, treatment with VPA and TSA increased the VEGI and DR3 expression levels without inducing DcR3 production in the OS cell lines. In contrast, the effect on the HMVE cells was limited, with no evidence of growth inhibition or an increase in the DR3 and DcR3 expression. However, VPA-induced soluble VEGI in the OS cell culture medium markedly inhibited the vascular tube formation of HMVE cells, while VEGI overexpression resulted in enhanced OS cell death. Taken together, the HDAC inhibitor has anti-angiogenesis and antitumor activities that mediate soluble VEGI/DR3-induced apoptosis via both autocrine and paracrine pathways. This study indicates that the HDAC inhibitor may be exploited as a therapeutic strategy modulating the soluble VEGI/DR3 pathway in osteosarcoma patients.

Death receptor 3 mediates TNFSF15- and TNFα-induced endothelial cell apoptosis

Tumor necrosis factor superfamily 15 (TNFSF15) suppresses angiogenesis by specifically inducing apoptosis in proliferating endothelial cells. Death receptor 3 (DR3), a member of the TNF receptor superfamily (TNFRSF25), has been identified as a receptor for TNFSF15 to activate T cells. It is unclear, however, whether DR3 mediates TNFSF15 activity on endothelial cells. Here we show that siRNA-mediated knockdown of DR3 in an in vivo Matrigel angiogenesis assay, or in adult bovine aortic endothelial (ABAE) cell cultures, leads to resistance of endothelial cells to TNFSF15-induced apoptosis. Interestingly, DR3-depleted cells also exhibited markedly diminished responsiveness to TNFα cytotoxicity, even though DR3 is not a receptor for TNFα. Treatment of the cells with either TNFSF15 siRNA or a TNFSF15-neutralizing antibody, 4-3H, also results in a significant inhibition of TNFα-induced apoptosis. Mechanistically, DR3 siRNA treatment gives rise to an increase of ERK1/2 MAPK activity, and up-regulation of the anti-apoptotic proteins c-FLIP and Bcl-2, thus strengthening apoptosis-resisting potential in the cells. These findings indicate that DR3 mediates TNFSF15-induced endothelial cell apoptosis, and that up-regulation of TNFSF15 expression stimulated by TNFα is partly but significantly responsible for TNFα-induced apoptosis in endothelial cells.

Interferon-γ produced by tumor-infiltrating NK cells and CD4+ T cells downregulates TNFSF15 expression in vascular endothelial cells

Endothelial cells in an established vasculature secrete tumor necrosis factor superfamily-15 (TNFSF15; VEGI; TL1A) that functions as a negative modulator of neovascularization to maintain blood vessel stability. TNFSF15 gene expression diminishes at angiogenesis and inflammation sites such as in cancers and wounds. We reported previously that vascular endothelial growth factor and monocyte chemotactic protein-1 contribute to TNFSF15 downmodulation in ovarian cancer. Here we show that interferon-γ (IFNγ) suppresses TNFSF15 expression in human umbilical vein endothelial cells. This activity is mediated by IFNγ receptor and the transcription factor STAT1. Immunohistochemical analysis of ovarian cancer clinical specimens indicates that TNFSF15 expression diminishes while tumor vascularity increases in specimens with high-grades of IFNγ expression. Since tumor-infiltrating NK and CD4(+) T cells are the main sources of IFNγ in tumor lesions, we isolated these cells from peripheral blood of healthy individuals, treated the cells with ovarian cancer OVCAR3 cell-conditioned media, and found a onefold and tenfold increase of IFNγ production in NK and CD4(+) T cells, respectively, compared with that in vehicle-treated cells. These findings support the view that tumor-infiltrating NK and CD4(+) T cells under the influence of cancer cells significantly increase the production of IFNγ, which in turn inhibits TNFSF15 expression in vascular endothelial cells, shifting the balance of pro- and anti-angiogenic factors toward escalated angiogenesis potential in the tumor.

TNFSF15 inhibits vasculogenesis by regulating relative levels of membrane-bound and soluble isoforms of VEGF receptor 1

Mouse bone marrow-derived Lin(-)-Sca-1(+) endothelial progenitor cell (EPC) has pluripotent abilities such as supporting neovascularization. Vascular endothelial growth factor (VEGF) receptor 1 (VEGFR1) (Flt1) recognizes various VEGF isoforms and is critically implicated in a wide range of physiological and pathological settings, including vasculogenesis. Mouse EPC expresses two isoforms of VEGFR1: mFlt1, which transmits ligand-induced signals; and sFlt1, which acts as a negative regulator by sequestering ligands of VEGF receptors. How the relative levels of mFlt1 and sFlt1 are regulated is not yet clear. We report here that tumor necrosis factor superfamily 15 (TNFSF15) (also known as VEGI or TL1A), an endothelial cell-secreted cytokine, simultaneously promotes mFlt1 degradation and up-regulates sFlt1 expression in EPC, giving rise to disruption of VEGF- or PlGF-induced activation of eNOS and MAPK p38 and effective inhibition of VEGF-driven, EPC-supported vasculogenesis in a murine Matrigel implant model. TNFSF15 treatment of EPC cultures facilitates Akt deactivation-dependent, ubiquitin-assisted degradation of mFlt1 and stimulates sFlt1 expression by activating the PKC, Src, and Erk1/2 signaling pathway. Additionally, TNFSF15 promotes alternative splicing of the Flt1 gene in favor of sFlt1 production by down-regulating nuclear protein Jumonji domain-containing protein 6 (Jmjd6), thus alleviating Jmjd6-inhibited sFlt1 expression. These findings indicate that TNFSF15 is a key component of a molecular mechanism that negatively modulates EPC-supported vasculogenesis through regulation of the relative levels of mFlt1 and sFlt1 in EPC.

Suppression of renal cell carcinoma growth in vivo by forced expression of vascular endothelial growth inhibitor

Vascular endothelial growth inhibitor (VEGI) has been associated with tumor-related vasculature in certain malignancies. However, its implication in renal cell carcinoma (RCC), an angiogenesis-dependent tumor, remains unknown. In the present study, we investigated the role played by VEGI in RCC. The expression of VEGI was examined in human renal tissue and RCC cell lines using immunohistochemical staining and RT-PCR, respectively. The biological impact of modifying the expression of VEGI in RCC cells was evaluated using in vitro and in vivo models. We show that VEGI mRNA is expressed in a wide variety of human RCC cell lines, all of normal renal and most of RCC tissue specimens. VEGI protein expression was observed in normal renal tubular epithelial cells, but was decreased or absent in RCC specimens, particularly in tumors with high grade. Moreover, forced expression of VEGI led to an inhibition of vascular endothelial tube formation, decrease in the motility and adhesion of RCC cells in vitro. Interestingly, forced expression of VEGI had no bearing on growth, apoptosis and invasive capacity of RCC cells. However, tumor growth was reduced in xenograft models. Immunohistochemical staining showed that microvessel density decreased in VEGI forced expression xenograft tumor samples. Taken together, our findings showed that the expression of VEGI is decreased in RCC, particularly in tumors with higher grade. Together with its inhibitory effect on cellular motility, adhesion, vascular endothelial tube formation and tumor growth in vivo, this suggests that VEGI functions mainly through inhibition of angiogenesis and is a negative regulator of aggressiveness during the development and progression of RCC.

Human embryonic stem cell-derived endothelial cells as cellular delivery vehicles for treatment of metastatic breast cancer

Endothelial progenitor cells (EPCs) have shown tropism towards primary tumors or metastases and are thus potential vehicles for targeting tumor therapy. However, the source of adult EPCs is limited, which highlights the need for a consistent and renewable source of endothelial cells for clinical applications. Here, we investigated the potential of human embryonic stem cell-derived endothelial cells (hESC-ECs) as cellular delivery vehicles for therapy of metastatic breast cancer. In order to provide an initial assessment of the therapeutic potency of hESC-ECs, we treated human breast cancer MDA-MB-231 cells with hESC-EC conditioned medium (EC-CM) in vitro. The results showed that hESC-ECs could suppress the Wnt/β-catenin signaling pathway and thereby inhibit the proliferation and migration of MDA-MB-231 cells. To track and evaluate the possibility of hESC-EC-employed therapy, we employed the bioluminescence imaging (BLI) technology. To study the therapeutic potential of hESC-ECs, we established lung metastasis models by intravenous injection of MDA-MB-231 cells labeled with firefly luciferase (Fluc) and green fluorescent protein (GFP) to NOD/SCID mice. In mice with lung metastases, we injected hESC-ECs armed with herpes simplex virus truncated thymidine kinase (HSV-ttk) intravenously on days 11, 16, 21, and 26 after MDA-MB-231 cell injection. The NOD/SCID mice were subsequently treated with ganciclovir (GCV), and the growth status of tumor was monitored by Fluc imaging. We found that MDA-MB-231 tumors were significantly inhibited by intravenously injected hESC-ECs. The tumor-suppressive effects of the hESC-ECs, by inhibiting Wnt/β-catenin signaling pathway and inducing tumor cell death through bystander effect in human metastatic breast cancer model, provide previously unexplored therapeutic modalities for cancer treatment.

In vitro labeling of endothelial progenitor cells isolated from peripheral blood with superparamagnetic iron oxide nanoparticles

The transplantation of endothelial progenitor cells (EPCs) provides a novel method for the treatment of human tumors or vascular diseases. Magnetic resonance imaging (MRI) has proven to be effective in tracking transplanted stem cells by labeling the cells with superparamagnetic iron oxide (SPIO) nanoparticles. The SPIO has been used to label and track the EPCs; however, the effect of SPIO upon EPCs remains unclear on a cellular level. In the present study, EPCs were labeled with home-synthesized SPIO nanoparticles in vitro and the biological characteristics of the labeled EPCs were evaluated. The EPCs were isolated from the peripheral blood of New Zealand rabbits and cultured in fibronectin-coated culture flasks. The EPCs were labeled with home-synthesized SPIO nanoparticles at a final iron concentration of 20 µg/ml. Labeled EPCs were confirmed with transmission electron microscopy and Prussian blue staining. The quantity of iron/cell was detected by atomic absorption spectrometry. The membranous antigens of EPCs were detected by cytofluorimetric analysis. Cell viability and proliferative capability between the labeled and unlabeled EPCs were compared. The rabbit EPCs were effectively labeled and the labeling efficiency was approximately 95%. The SPIO nanoparticles were localized in the endosomal vesicles of the EPCs, which were confirmed by transmission electron microscopy. No significant differences were found in cell viability and proliferative capability between labeled and unlabeled EPCs (P>0.05). In conclusion, rabbit peripheral blood EPCs were effectively labeled by home-synthesized SPIO nanoparticles, without influencing their main biological characteristics.

TNFSF15 Modulates Neovascularization and Inflammation

Tumor necrosis factor superfamily-15 (TNFSF15; also known as VEGI or TL1A) is a unique cytokine that functions in the modulation of vascular homeostasis and inflammation. TNFSF15 is expressed abundantly in established vasculature but is down-regulated at sites of neovascularization such as in cancers and wounds. TNFSF15 inhibits endothelial cell proliferation and endothelial progenitor cell differentiation. Additionally, TNFSF15 stimulates T cell activation, Th1 cytokine production, and dendritic cell maturation. Some of the functions of TNFSF15 are mediated by death receptor-3. We review the experimental evidences on TNFSF15 activities in angiogenesis, vasculogenesis, inflammation, and immune system mobilization.

Thrombospondin-1 mimetic peptide ABT-898 affects neovascularization and survival of human endometriotic lesions in a mouse model

Endometriosis is a common cause of pelvic pain and infertility in women, and a common indication for hysterectomy, yet the disease remains poorly diagnosed and ineffectively treated. Because endometriotic lesions require new blood supply for survival, inhibiting angiogenesis could provide a novel therapeutic strategy. ABT-898 mimics the antiangiogenic properties of thrombospondin-1, so we hypothesized that ABT-898 will prevent neovascularization of human endometriotic lesions and that ABT-898 treatment will not affect reproductive outcomes in a mouse model. Endometriosis was induced in BALB/c-Rag2(-/-)Il2rg(-/-) mice by surgical implantation of human endometrial fragments in the peritoneal cavity. Mice received daily injections of ABT-898 for 21 days. Flow cytometry was performed to measure circulating endothelial progenitor cells in peripheral blood. Cytokines were measured in plasma samples. Half of the ABT-898-treated and control mice were euthanized to assess neovascularization of endometriotic lesions, using CD31(+) immunofluorescence. The remaining mice were mated and euthanized at gestation day 12. Endometriotic lesions increased circulating endothelial progenitor cells 13 days after engraftment, relative to baseline. Endometriotic lesions from ABT-898-treated mice exhibited reduced neovascularization, compared with controls, and lesions had fewer CD31(+) microvessels. Chronic treatment with ABT-898 did not lead to any fetal anomalies or affect litter size at gestation day 12, compared with controls. Our results suggest that ABT-898 inhibits neovascularization of human endometriotic lesions without affecting mouse fecundity.

Down-modulation of TNFSF15 in ovarian cancer by VEGF and MCP-1 is a pre-requisite for tumor neovascularization

Persistent inflammation and neovascularization are critical to cancer development. In addition to upregulation of positive control mechanisms such as overexpression of angiogenic and inflammatory factors in the cancer microenvironment, loss of otherwise normally functioning negative control mechanisms is likely to be an important attribute. Insights into the down-modulation of such negative control mechanisms remain largely unclear, however. We show here that tumor necrosis factor superfamily-15 (TNFSF15), an endogenous inhibitor of neovascularization, is a critical component of the negative control mechanism that operates in normal ovary but is missing in ovarian cancer. We show in clinical settings that TNFSF15 is present prominently in the vasculature of normal ovary but diminishes in ovarian cancer as the disease progresses. Vascular endothelial growth factor (VEGF) produced by cancer cells and monocyte chemotactic protein-1 (MCP-1) produced mainly by tumor-infiltrating macrophages and regulatory T cells effectively inhibits TNFSF15 production by endothelial cells in vitro. Using a mouse syngeneic tumor model, we demonstrate that silencing TNFSF15 by topical shRNA treatments prior to and following mouse ovarian cancer ID8 cell inoculation greatly facilitates angiogenesis and tumor growth, whereas systemic application of recombinant TNFSF15 inhibits angiogenesis and tumor growth. Our findings indicate that downregulation of TNFSF15 by cancer cells and tumor infiltrating macrophages and lymphocytes is a pre-requisite for tumor neovascularization.