Geniposide alleviates imiquimod-induced psoriasis-like skin lesions in mice via inhibition of angiogenesis

In this study, we aimed to evaluate the protective effect of geniposide (GEN) on imiquimod (IMQ)-induced psoriasis-like skin lesions in mice. Firstly, visual changes of psoriatic skin lesions were observed and the severity was recorded using psoriasis area and severity index (PASI) score. Histological changes were assessed by HE staining for epidermal thickness and Masson's staining for collagen fibers. Then, photographs of microvascular inside the skin were taken for macroscopic observation, and microscopic changes associated with angiogenesis were evaluated. Furthermore, expression of angiogenic factors were analyzed by ELISA, immunohistochemistry and immunofluorescence, separately. Lastly, the expression of VEGFR signaling-related proteins was detected by WB. Compared with control, IMQ drove a significant increment of epidermal thicknesses with higher PASI scores and more dermal collagen deposition. IMQ treatment led to abnormal keratinocyte proliferation, increased microvascular inside skin, growing production of angiogenesis-related factors, up-regulated expression of VEGFR1 and VEGFR2, and enhanced phosphorylation of p38. However, GEN significantly ameliorated the psoriatic skin lesions, the epidermal thickness, the formation of collagen fibers, and abnormal keratinocyte proliferation. Importantly, GEN inhibited angiogenesis, the production of angiogenic factors (VEGF-A, Ang-2, TNF-α, and IL-17A), and the proliferation of vascular endothelial cells. Simultaneously, GEN curbed the expression of VEGFR1, VEGFR2, p38, and P-p38 proteins involved in VEGFR signaling. Of note, the suppressive effect of GEN was reversed in the HUVECs with over-expressed VEGFR1 or VEGFR2 related to the cells without transfection. These findings suggest that VEGFR1 and VEGFR2 participate in the anti-angiogenesis of GEN in IMQ-induced psoriasis-like skin lesions in mice.

Anti-TPO-mediated specific features of the placenta immunohistochemical profile and possible mechanisms for fetal loss

Passive transfer of antithyroid antibodies in mice leads to reproductive disorders. The purpose was to assess the placental tissue of experimental animals under the influence of the circulating thyroperoxidase antibodies. We performed an immunohistochemical examination of murine placentae after a passive transfer of thyroperoxidase antibodies. Placentae of mice that were passively transferred IgG from healthy donors were used as control samples. For histological examination, 30 placental samples were selected from mice from the anti-TPO group and 40 placental samples were taken from mice from the IgG group. Immunostaining for VEGFR1, THBS 1, Laminin, CD31, CD34, FGF-β, CD56, CD14, TNF-α, kisspeptin, MCL 1 and Annexin V was performed. There is a significant decrease in the relative area of the expression of: VEGFR1 (23.42±0.85 vs. 33.44±0.35, р<0.01), thrombospondin 1 (31.29±0.83 vs. 34.51±0.75, р<0.01), CD14 (25.80±0.57 vs. 32.07±0.36, р<0.01), CD56 (30.08±0.90 vs. 34.92±0.15, р<0.01), kisspeptin (25.94±0.47 vs. 31.27±0.57, р<0.01), MCL 1 (29.24±1.06 vs. 38.57±0.79, р<0.01) in the labyrinth zone of the placentae of mice from the anti-TPO group compare with control group. A significant increase in relative expression of laminin and FGF-β was noted in the group of mice to which antibodies to thyroperoxidase were transferred, compared with the control group (36.73±1.38 vs. 29.83±0.94, р<0.01 and 23.26±0.61 vs. 16.38±1.01, р<0.01respectively). Our study exposed an imbalance of pro- and anti-angiogenic factors, decreased representation of placental macrophages and NK cells, abnormal trophoblast invasion processes, insufficient expression of antiapoptotic factors in the placentae of mice in which anti-TPO antibodies were passively transferred.

Suramin Affects the Renal VEGF-A/VEGFR Axis in Short-Term Streptozotocin-Induced Diabetes

Diabetic nephropathy (DN) accounts for approximately 50% of end-stage renal diseases. Vascular endothelial growth factor A (VEGF-A) is thought to be a critical mediator of vascular dysfunction in DN, but its role is unclear. The lack of pharmacological tools to modify renal concentrations further hinders the understanding of its role in DN. In this study, rats were evaluated after 3 weeks of streptozotocin-induced diabetes and two suramin treatments (10 mg/kg, ip). Vascular endothelial growth factor A expression was evaluated by western blot of glomeruli and immunofluorescence of the renal cortex. RT-PCR for receptors Vegfr1 mRNA and Vegfr2 mRNA quantitation was performed. The soluble adhesive molecules (sICAM-1, sVCAM-1) in blood were measured by ELISA and the vasoreactivity of interlobar arteries to acetylcholine was evaluated using wire myography. Suramin administration reduced the expression and intraglomerular localisation of VEGF-A. Increased VEGFR-2 expression in diabetes was reduced by suramin to non-diabetic levels. Diabetes reduced the sVCAM-1 concentrations. Suramin in diabetes restored acetylcholine relaxation properties to non-diabetic levels. In conclusion, suramin affects the renal VEGF-A/VEGF receptors axis and has a beneficial impact on endothelium-dependent relaxation of renal arteries. Thus, suramin may be used as a pharmacological agent to investigate the potential role of VEGF-A in the pathogenesis of renal vascular complications in short-term diabetes.

Evaluation of VEGF and VEGFR gene expression as prognostic markers in low and intermediate‑1 risk patients with myelodysplastic syndromes

Vascular endothelial growth factors (VEGFs) are angiogenic factors playing a key role in tumor development. VEGFs are produced by different normal and tumor cells, including platelets, lymphocytes and mononuclear cells of peripheral blood. VEGF (VEGF-A, VEGF-C and VEGF-D) and VEGFR (VEGFR1, VEGFR2 and VEGFR3) gene expression was studied in patients with myelodysplastic syndrome (MDS) to evaluate the possible prognostic role of the expression of these genes. Gene expression levels were determined using peripheral blood samples of 51 patients with MDS and 15 healthy volunteers by quantitative PCR. Expression of all VEGF and VEGFR genes was elevated in patients with MDS compared with healthy volunteers. No association of VEGF-A expression with the hemoglobin content in peripheral blood was found. The analyses of gene expression in patients with MDS stratified by risk groups according to the International Prognostic Scoring System showed progressive augmentation of VEGF-A gene expression from low to high-risk groups and VEGFR1 and VEGFR2 expression from intermediate-1 to high-risk groups. The statistically significant difference in survival time of patients with high and low levels of VEGFR1 expression was revealed. VEGF-A/VEGFR1 expression may be important for risk evaluation of patients with MDS.

SNPs in 3'UTR miRNA Target Sequences Associated with Individual Drug Susceptibility

The complementary interaction of microRNAs (miRNAs) with their binding sites in the 3'untranslated regions (3'UTRs) of target gene mRNAs represses translation, playing a leading role in gene expression control. MiRNA recognition elements (MREs) in the 3'UTRs of genes often contain single nucleotide polymorphisms (SNPs), which can change the binding affinity for target miRNAs leading to dysregulated gene expression. Accumulated data suggest that these SNPs can be associated with various human pathologies (cancer, diabetes, neuropsychiatric disorders, and cardiovascular diseases) by disturbing the interaction of miRNAs with their MREs located in mRNA 3'UTRs. Numerous data show the role of SNPs in 3'UTR MREs in individual drug susceptibility and drug resistance mechanisms. In this review, we brief the data on such SNPs focusing on the most rigorously proven cases. Some SNPs belong to conventional genes from the drug-metabolizing system (in particular, the genes coding for cytochromes P450 (CYP 450), phase II enzymes (SULT1A1 and UGT1A), and ABCB3 transporter and their expression regulators (PXR and GATA4)). Other examples of SNPs are related to the genes involved in DNA repair, RNA editing, and specific drug metabolisms. We discuss the gene-by-gene studies and genome-wide approaches utilized or potentially utilizable to detect the MRE SNPs associated with individual response to drugs.

VEGF-A promotes the motility of human melanoma cells through the VEGFR1-PI3K/Akt signaling pathway

Vascular endothelial growth factor A (VEGF-A) and its receptors (VEGFR1 and R2) play important roles in the progression of malignant melanoma through tumor angiogenesis. However, it is not clear whether the VEGF-A/VEGFR1 signaling pathway is involved in the proliferation and migration of melanoma cells. Thus, the effect of VEGF-A on cell migration was investigated in human melanoma cell lines. Of several splicing variants of VEGF-A, VEGF₁₆₅ is the most abundant and responsible for VEGF-A biological potency. VEGF₁₆₅ facilitated the migration of melanoma cells in both a chemotactic and chemokinetic manner, but cell proliferation was not affected by VEGF₁₆₅. VEGF₁₆₅ also induced the phosphorylation of Akt. In addition, VEGF₁₆₅-induced cell migration was inhibited significantly by VEGFR1/2 or a VEGFR1-neutralizing antibody. Furthermore, the downregulation of VEGFR1 via the transfection of VEGFR1-targeting antisense oligonucleotides suppressed VEGF₁₆₅-induced cell migration. Moreover, wortmannin, an inhibitor of phosphatidylinositol-3 kinase (PI3K) in the PI3K/Akt pathway, suppressed VEGF₁₆₅-induced Akt phosphorylation and VEGF₁₆₅-induced cell migration. These findings suggest that the motility of melanoma cells is regulated by signals mediated through the PI3K/Akt kinase pathway with the activation of VEGFR1 tyrosine kinase by VEGF₁₆₅. Thus, the downregulation of signaling via VEGF-A/VEGFR1 might be an effective therapeutic approach that could prevent the progression of malignant melanoma.

VEGF Receptor 1 Promotes Hypoxia-Induced Hematopoietic Progenitor Proliferation and Differentiation

Although it is well known that hypoxia incites unleashed cellular inflammation, the mechanisms of exaggerated cellular inflammation in hypoxic conditions are not known. We observed augmented proliferation of hematopoietic stem and progenitor cells (HSPC), precursors of inflammatory leukocytes, in mice under hypoxia. Consistently, a transcriptomic analysis of human HSPC exposed to hypoxic conditions revealed elevated expression of genes involved in progenitor proliferation and differentiation. Additionally, bone marrow cells in mice expressed high amount of vascular endothelial growth factor (VEGF), and HSPC elevated VEGF receptor 1 (VEGFr1) and its target genes in hypoxic conditions. In line with this, VEGFr1 blockade in vivo and in vitro decreased HSPC proliferation and attenuated inflammation. In silico and ChIP experiments demonstrated that HIF-1α binds to the promoter region of VEGFR1. Correspondingly, HIF1a silencing decreased VEGFr1 expression in HSPC and diminished their proliferation. These results indicate that VEGF signaling in HSPC is an important mediator of their proliferation and differentiation in hypoxia-induced inflammation and represents a potential therapeutic target to prevent aberrant inflammation in hypoxia-associated diseases.

HIF1A promotes miR-210/miR-424 transcription to modulate the angiogenesis in HUVECs and HDMECs via sFLT1 under hypoxic stress

Angiogenesis is a critical process during human skin wound healing. However, hypoxia might lead to the dysfunction of the cellular interplay of endothelial cells and subcutaneous fibroblasts, resulting in the deregulation of angiogenesis. HIF1A is a key regulatory of the recovery of intracellular homeostasis under hypoxia. In the present study, the detailed role and mechanism of HIF1A in the angiogenesis under hypoxia were investigated. Via bioinformatic analyses on microarray profiles (GSE1041 and GSE17944), solube fms-related tyrosine kinase 1 (sFLT1, also known as sVEGFR1) and miR-210/miR-424 might be involved in HIF1A function on the angiogenesis under hypoxia in human umbilical vascular endothelium cells (HUVECs) and human dermal microvascular endothelial cells (HDMECs). In the present study, we identified sFLT1 as a downregulated gene in response to hypoxia and HIF1A overexpression in HUVECs and HDMECs. sFLT1 overexpression inhibited the capacity of migration and angiogenesis and significantly reversed the inducible effects of HIF1A on the migration and angiogenesis in both cell lines. miR-210 and miR-424 were upregulated by hypoxia and targeted sFLT1 3'-UTR to negatively modulate its expression. HIF1A modulated sFLT1 expression, VEGF signaling, and the migration and angiogenesis in HUVECs and HDMECs via miR-210/miR-424. Regarding the molecular mechanism, HIF1A bound the promoter region of miR-210 and miR-424 to activate their transcription, while miR-210/miR-424 bound sFLT1 3'-UTR to suppress its expression. In summary, HIF1A/miR-210/miR-424/sFLT1 axis modulates the angiogenesis in HUVECs and HDMECs upon hypoxic condition via VEGF signaling.

Apoptosis induction in human lung and colon cancer cells via impeding VEGF signaling pathways

There is ample evidence to suggest that vascular endothelial growth factor (VEGF) is a potent mitogen factor in vasculogenesis and angiogenesis and that blockade of VEGF-mediated signals can also prevent tumor growth via enforcing cell apoptosis. In the current study, we assessed the suppressing effect of VGB4, a VEGF antagonist peptide with the binding ability to both VEGF receptor1 and VEGF receptor2, on VEGF-induced proliferation and migration of the human lung adenocarcinoma cell line A549 and the human colon adenocarcinoma cell line HT29 using MTT assay, colony formation assay, and Scratch-wound assay. To evaluate the apoptotic inductive effect of VGB4 on A549 and HT29 cells, apoptosis analysis was carried out by flow cytometry and TUNEL assay. Likewise, p53 and PTEN expression level was examined by immunofluorescence microscopy. In addition, the level of proteins involved in VEGF signaling pathways related to apoptosis was investigated using western blot analysis. Our results indicated that VGB4 markedly inhibited VEGF-induced proliferation and migration, and induced apoptosis of A549 and HT29 cells dose dependently. Encouragingly, significant downregulation of B-cell lymphoma 2 (Bcl2), X-linked inhibitor of apoptosis, Procaspase9, and procaspase3, as well as upregulation of PTEN and P53 tumor suppressors, BCL2 associated X, Cytochrome c, cleaved caspase9, and cleaved caspase3 in VGB4-treated A549 and HT29 cells, further confirmed the profound inductive influence of VGB4 on apoptotic pathways. These findings along with the results from our previous studies show that VGB4 may be considerable for cancer therapy.

Immunohistochemical expression of VEGFR1 in non small cell lung carcinomas: Lower VEGFR1 expression is asociated with squamous cell carcinoma subtype and high SUV max values in 18F-FDG PET

BACKGROUND

To study the possible relation between immunohistochemical expression of vascular endothelial growth factor receptor 1 (VEGFR1) and the maximum standardised uptake value (SUV max) of ¹⁸F-FDG PET in patients with non small cell lung cancer (NSCLC).

MATERIAL AND METHODS

The study included 39 patients with NSCLC (24 squamous cell carcinomas and 15 adenocarcinomas). According to the clinical stage, the patients were distributed as follows: 8 stage I, 7 stage II, 15 stage III and 9 stage IV. Immunohistochemical expression of VEGFR1 was studied through the technique of tissue-matrix using Tissue Arrayer Device (Beecher Instruments, Sun Prairie, WI), using the polyclonal antibody against VEGFR1 (Santa Cruz Biotechnology, California, USA).

RESULTS

Positive VEGFR1 immunohistochemical expression was noted in 23 cases (59%). The number of positive tumours was not related with clinical stage but there was a different statistically significant association (p:0,0009) between VEGFR1 positivity and histological type, corresponding the greater percentages of positive results to adenocarcinomas (93,3%) versus in squamous cell carcinomas (37,5%). Likewise, SUV max values were higher (p: 0,039) in negative VEGFR1 carcinomas than in positive VEGFR1 tumors (r: 4-32,1; 16,4+/-6,4 (median 16,1) vs r: 3-47; 14,5+/-8,6 (12,8)).

CONCLUSIONS

Our results led us to consider that in NSCLC, the negative VEGFR1 immunohistochemical expression is associated significantly with squamous cell carcinomas subtype and with higher SUV max values in ¹⁸F-FDG-PET.

Conjugation of VEGFR1/R2-targeting peptide with gold nanoparticles to enhance antiangiogenic and antitumoral activity

BACKGROUND

Inhibition of tumor angiogenesis through simultaneous targeting of vascular endothelial growth factor receptor (VEGFR)-1 and -2 is highly efficacious. An antagonist peptide of VEGFA/VEGFB, referred to as VGB3, can recognize and neutralize both VEGFR1 and VEGFR2 on the endothelial and tumoral cells, thereby inhibits angiogenesis and tumor growth. However, improved efficacy and extending injection intervals is required for its clinical translation. Given that gold nanoparticles (GNPs) can enhance the efficacy of biotherapeutics, we conjugated VGB3 to GNPs to enhance its efficacy and extends the intervals between treatments without adverse effects.

RESULTS

GNP-VGB3 bound to VEGFR1 and VEGFR2 in human umbilical vein endothelial (HUVE) and 4T1 mammary carcinoma cells. GNP-VGB3 induced cell cycle arrest, ROS overproduction and apoptosis and inhibited proliferation and migration of endothelial and tumor cells more effectively than unconjugated VGB3 or GNP. In a murine 4T1 mammary carcinoma tumor model, GNP-VGB3 more strongly than VGB3 and GNP inhibited tumor growth and metastasis, and increased animal survival without causing weight loss. The superior antitumor effects were associated with durable targeting of VEGFR1 and VEGFR2, thereby inhibiting signaling pathways of proliferation, migration, differentiation, epithelial-to-mesenchymal transition, and survival in tumor tissues. MicroCT imaging and inductively coupled plasma mass spectrometry showed that GNP-VGB3 specifically target tumors and exhibit greater accumulation within tumors than the free GNPs.

CONCLUSION

Conjugation to GNPs not only improved the efficacy of VGB3 peptide but also extended the intervals between treatments without adverse effects. These results suggest that GNP-VGB3 is a promising candidate for clinical translation.

VEGFB Promotes Myoblasts Proliferation and Differentiation through VEGFR1-PI3K/Akt Signaling Pathway

It has been demonstrated that vascular endothelial growth factor B (VEGFB) plays a vital role in regulating vascular biological function. However, the role of VEGFB in regulating skeletal muscle cell proliferation and differentiation remains unclear. Thus, this study aimed to investigate the effects of VEGFB on C2C12 myoblast proliferation and differentiation and to explore the underlying mechanism. For proliferation, VEGFB significantly promoted the proliferation of C2C12 myoblasts with the upregulating expression of cyclin D1 and PCNA. Meanwhile, VEGFB enhanced vascular endothelial growth factor receptor 1 (VEGFR1) expression and activated the PI3K/Akt signaling pathway in a VEGFR1-dependent manner. In addition, the knockdown of VEGFR1 and inhibition of PI3K/Akt totally abolished the promotion of C2C12 proliferation induced by VEGFB, suggesting that VEGFB promoted C2C12 myoblast proliferation through the VEGFR1-PI3K/Akt signaling pathway. Regarding differentiation, VEGFB significantly stimulated the differentiation of C2C12 myoblasts via VEGFR, with elevated expressions of MyoG and MyHC. Furthermore, the knockdown of VEGFR1 rather than NRP1 eliminated the VEGFB-stimulated C2C12 differentiation. Moreover, VEGFB activated the PI3K/Akt/mTOR signaling pathway in a VEGFR1-dependent manner. However, the inhibition of PI3K/Akt/mTOR blocked the promotion of C2C12 myoblasts differentiation induced by VEGFB, indicating the involvement of the PI3K/Akt pathway. To conclude, these findings showed that VEGFB promoted C2C12 myoblast proliferation and differentiation via the VEGFR1-PI3K/Akt signaling pathway, providing new insights into the regulation of skeletal muscle development.

[Application of iPDMS protein microarray in screening of tumor-associated antigen autoantibodies]

The rapid screening of tumor markers is a challenging task for early diagnosis of cancer. This study aims to use highly sensitive chemiluminescent protein microarray technology to efficiently screen a variety of low abundance tumor related markers. A new material, termed integrated polydimethylsiloxane modified silica gel (iPDMS), was obtained by adding a surface polymerization initiator with olefin end to the conventional polydimethylsiloxane, and fixing into the three-dimensional structure of polydimethylsiloxane by thermal crosslinking through silicon hydrogen bonding. In order to make the iPDMS material resistant to non-specific protein adsorption, a poly(OEGMA) polymer brush was synthesized by surface-initiated atom transfer radical polymerization at the active initiation site. Finally, 20 tumor-related antigens were printed into the specific areas of the microarray by high-throughput spray printing technology, and assembled into 48-well detection microtiterplates of the iPDMS microarray. It was found the VEGFR and VEGF121 autoantibodies that obtained from 8 common tumors (breast cancer, lung cancer, colon cancer, gastric cancer, liver cancer, leukemia, lymphoma and ovarian cancer) can be used as potential tumor markers. The chemiluminescence labeled iPDMS protein microarray can be used for the screening of tumor autoantibodies at early stage.

Expression of Vascular Endothelial Growth Factor A and Its Type 1 Receptor in Supratentorial Neoplasm

BACKGROUND

Vascular endothelial growth factor (VEGF) is one of the primary angiogenesis regulators in solid cancers. Brain solid tumors are life-threatening diseases in which angiogenesis is an important phase of tumor development and progression. In the present study, VEGF-A and VEGF receptor (VEGF-R1) gene expression was evaluated in CNS brain tumors.

METHODS

VEGF-A and VEGF-R1 expression was quantified using real-time PCR on fresh biopsies of 38 supratentorial brain tumors compared to 30 non-tumoral tissues. Then, the correlations were investigated with clinic-pathological and demographic factors of the patients.

RESULTS

PCR product sequencing confirmed the validity of qRT-PCR. Although VEGF-A and VEGF-R1 expression showed increasing trends with the progression of cell proliferation in different stages of astrocytoma, VEGF-R1 did not meet the 95% confidence interval in other brain tumors. An increasing trend in VEGF-A expression and a declining trend in VEGF-R1 expression from Stage I to II were observed in meningioma. VEGF-A and VEGF-R1 expression had no significant correlation with age and gender. Although peritumoral brain edema (PTBE) in astrocytoma was significantly associated with tumor stages, VEGF-A and VEGF-R1 were not correlated with PTBE in meningioma and metastasis.

CONCLUSION

VEGF-A is a valuable factor for the prognosis of PTBE and malignancy in astrocytoma and is helpful in monitoring treatment approaches.

Curcumol inhibits EBV-positive Nasopharyngeal carcinoma migration and invasion by targeting nucleolin

Metastasis is a major cause of recurrence and death in patients with EBV-positive Nasopharyngeal carcinoma (NPC). Previous reports documented that curcumol has both anti-cancer and anti-viral effects, but there is little literature systematically addressing the mechanism of curcumol in EBV-positive tumors. Previously we found that nucelolin (NCL) is a target protein of curcumol in CNE2 cells, an EBV-negative NPC, and in this experiment, we reported a critical role for NCL in promoting migration and invasion of C666-1 cells, an EBV-positive NPC, and found that the expression of NCL determined the level of curcumol's efficacy. Mechanistically, NCL interacted with Epstein-Barr Virus Nuclear Antigen 1 (EBNA1) to activate VEGFA/VEGFR1/PI3K/AKT signaling pathway, which in turn promoted NPC cell invasion and metastasis. Moreover, further study showed that the differential expression of NCL and curcumol intervention only had a regulatory effect on the nuclear accumulation of VEGFR1, which strengthened the anti-cancer effect of curcumol mediated through NCL. Our findings indicated that curcumol exerted anti EBV-positive NPC invasion and metastasis by downregulating EBNA1 and inhibiting VEGFA/VEGFR1/PI3K/AKT signaling by targeting NCL, which provides a novel pharmacological basis for curcumol's clinical use in treating patients with EBV-positive NPC.

Immunohistochemical expression of VEGFR1 in non small cell lung carcinomas: Lower VEGFR1 expression is asociated with squamous cell carcinoma subtype and high max SUV values in 18F-FDG PET

BACKGROUND

To study the possible relation between immunohistochemical expression of vascular endothelial growth factor receptor 1 (VEGFR1) and the maximum standardised uptake value (maxSUV) of 18F-FDG PET in patients with non small cell lung cancer.

MATERIAL AND METHODS

The study included 39 patients with NSCLC (24 squamous cell carcinomas and 15 adenocarcinomas). According to the clinical stage, the patients were distributed as follows: 8 stage I, 7 stage II, 15 stage III and 9 stage IV. Immunohistochemical expression of VEGFR1 was studied through the technique of tissue-matrix using tissue arrayer device (Beecher Instruments, Sun Prairie, WI), using the polyclonal antibody against VEGFR1 (Santa Cruz Biotechnology, California, USA).

RESULTS

Positive VEGFR1 immunohistochemical expression was noted in 23 cases (59%). The number of positive tumours was not related with clinical stage but there was a different statistically significant association (p:.0009) between VEGFR1 positivity and histological type, corresponding the greater percentages of positive results to adenocarcinomas (93.3%) versus in squamous cell carcinomas (37.5%). Likewise, maxSUV values were higher (p: .039) in negative VEGFR1 carcinomas than in positive VEGFR1 tumors (r: 4-32.1; 16.4+/-6.4 [median 16.1] vs. r: 3-47; 14.5+/-8.6 [12.8]).

CONCLUSIONS

Our results led us to consider that in NSCLC, the negative VEGFR1 immunohistochemical expression is associated significantly with squamous cell carcinomas subtype and with higher maxSUV values in 18F-FDG-PET.

Vascular endothelial growth factor B exerts lipid-lowering effect by activating AMPK via VEGFR1

As an ambiguous member of vascular endothelial growth factor family, VEGF-B has long been poorly understood in its function. Recent researches showed VEGF-B isoforms exerted their metabolic effect through indirectly activating the VEGF-A/VEGFR2 pathway. Here, we report the lipid-lowing effect of VEGF-B via VEGFR1. We investigated the effect of VEGF-B on lipid metabolism in vivo and in vitro approaches. Treatment of mice with VEGF-B recombinant protein repressed HFD-induced body weight gain. This treatment also alleviated obesity associated hyperlipidemia and fatty liver disease. In the muscle and liver of VEGF-B-treated HFD mice were observed increased protein expression of carnitine palmitoyltransferase-1 (CPT-1) and the phosphorylation of ACC and AMP-activated protein kinase (AMPK). This effect was confirmed in HepG2 cells incubated with VEFG-B in which the increased AMPK activation and CPT-1 expression occurs due to activation of Calcium/calmodulin-dependent Protein Kinase β (CaMKKβ) by VEFG-B. VEGF-B increased expression of key genes responsible for lipid oxidation while reducing those for fatty acid synthesis in vivo and in vitro. In addition, the selective inhibitor of VEGFR1 blocked the lipid clearance effect of VEGF-B in HepG2. Our study unraveled unknown role of VEGF-B/VEGFR1 signaling in regulating lipid metabolism. Furthermore, our findings indicate that VEGF-B may have beneficial effects for the treatment of dyslipidemia.

Pericytes Regulate Cerebral Perfusion through VEGFR1 in Ischemic Stroke

Neurons in the penumbra (the area surrounding ischemic tissue that consists of still viable tissue but with reduced blood flow and oxygen transport) may be rescued following stroke if adequate perfusion is restored in time. It has been speculated that post-stroke angiogenesis in the penumbra can reduce damage caused by ischemia. However, the mechanism for neovasculature formation in the brain remains unclear and vascular-targeted therapies for brain ischemia remain suboptimal. Here, we show that VEGFR1 was highly upregulated in pericytes after stroke. Knockdown of VEGFR1 in pericytes led to increased infarct area and compromised post-ischemia vessel formation. Furthermore, in vitro studies confirmed a critical role for pericyte-derived VEGFR1 in both endothelial tube formation and pericyte migration. Interestingly, our results show that pericyte-derived VEGFR1 has opposite effects on Akt activity in endothelial cells and pericytes. Collectively, these results indicate that pericyte-specific expression of VEGFR1 modulates ischemia-induced vessel formation and vascular integrity in the brain.

A role for aldehyde dehydrogenase (ALDH) 2 in angiotensin II-mediated decrease in angiogenesis of coronary endothelial cells

Diabetes-induced coronary endothelial cell (CEC) dysfunction contributes to diabetic heart diseases. Angiotensin II (Ang II), a vasoactive hormone, is upregulated in diabetes, and is reported to increase oxidative stress in CECs. 4-hydroxy-2-nonenal (4HNE), a key lipid peroxidation product, causes cellular dysfunction by forming adducts with proteins. By detoxifying 4HNE, aldehyde dehydrogenase (ALDH) 2 reduces 4HNE mediated proteotoxicity and confers cytoprotection. Thus, we hypothesize that ALDH2 improves Ang II-mediated defective CEC angiogenesis by decreasing 4HNE-mediated cytotoxicity. To test our hypothesis, we treated the cultured mouse CECs (MCECs) with Ang II (0.1, 1 and 10 μM) for 2, 4 and 6 h. Next, we treated MCECs with Alda-1 (10 μM), an ALDH2 activator or disulfiram (2.5 μM)/ALDH2 siRNA (1.25 nM), the ALDH2 inhibitors, or blockers of angiotensin II type-1 and 2 receptors i.e. Losartan and PD0123319 respectively before challenging MCECs with 10 μM Ang II. We found that 10 μM Ang II decreased tube formation in MCECs with in vitro angiogenesis assay (P < .0005 vs control). 10 μM Ang II downregulated the levels of vascular endothelial growth factor receptor 1 (VEGFR1) (p < .005 for mRNA and P < .05 for protein) and VEGFR2 (p < .05 for mRNA and P < .005 for protein) as well as upregulated the levels of angiotensin II type-2 receptor (AT2R) (p < .05 for mRNA and P < .005 for protein) and 4HNE-adducts (P < .05 for protein) in cultured MCECs, compared to controls. ALDH2 inhibition with disulfiram/ALDH2 siRNA exacerbated 10 μM Ang II-induced decrease in coronary angiogenesis (P < .005) by decreasing the levels of VEGFR1 (P < .005 for mRNA and P < .05 for protein) and VEGFR2 (P < .05 for both mRNA and protein) and increasing the levels of AT2R (P < .05 for both mRNA and protein) and 4HNE-adducts (P < .05 for protein) relative to Ang II alone. AT2R inhibition per se improved angiogenesis in MCECs. Additionally, enhancing ALDH2 activity with Alda 1 rescued Ang II-induced decrease in angiogenesis by increasing the levels of VEGFR1, VEGFR2 and decreasing the levels of AT2R. In summary, ALDH2 can be an important target in reducing 4HNE-induced proteotoxicity and improving angiogenesis in MCECs. Finally, we conclude ALDH2 activation can be a therapeutic strategy to improve coronary angiogenesis to ameliorate cardiometabolic diseases.

VEGF165b augments NK92 cytolytic activity against human K562 leukemia cells by upregulating the levels of perforin and granzyme B via the VEGR1-PLC pathway

Pro-angiogenic Vascular endothelial growth factors (VEGFs) exert immunosuppressive functions on some immune cells by interacting with VEGF receptors. Blocking the VEGF/VEGFR pathway could reverse the tumor immunosuppressive microenvironment to some degree. We recently demonstrated that the anti-angiogenic VEGF isoform VEGF165b, similar to other anti-angiogenic agents, inhibit the accumulation immunosuppressive cells such as Tregs and MDSCs. However, whether VEGF165b affects the functions of immune effector cells remain unclear. Here, NK92 cell line was utilized as an immune effector cell model. Our results verified that NK92 cells endogenously express VEGF165 and VEGFR1. Further investigation showed that NK92 treatment with VEGF165b augments its killing ability against human K562 leukemia cells by upregulating perforin and granzyme B through the VEGFR1-PLC pathway, whereas VEGF165b had no impact on the proliferation of NK92 cells in vitro. The results of this study improve our understanding of the immunomodulatory function of VEGF165b, which may help in enhancing the efficacy of NK92-based cancer immunotherapy.

TLR family gene expression in relation to the HIF1α and the VEGFR pathway activation in endometrial cancer

INTRODUCTION

Malignant neoplasm of the endometrium is the most common malignant neoplasm of the female reproductive system. Toll Like Receptors (TLR) play a significant role in innate and late-immunity against infections or damaged tissues. TLRs are also involved in the development of tumors in their natural microenvironment. TLRs play an important role in angiogenesis, necessary for survival and growth of the tumor. Hypoxia playing a critical role in angiogenesis, carcinogenesis, tumor progression and distant metastasis is primarily mediated through hypoxia inducible factors (HIFs). Vascular endothelial growth factor family proteins (VEGF) are also strongly involved in tumor angiogenesis and their action is strongly associated with TLR receptors.

OBJECTIVES

The aim of the study was to correlate the expression of selected TLRs and VEGFR's as well as HIF1α with clinicopathological data of endometrial cancer patients.

MATERIAL AND METHODS

123 neoplastic endometrial samples were included in the study. 51 samples of healthy endometrium served as control. The expression of TLR1, TLR2, TLR3, TLR4, VEGFR1 and VEGFR2, VEGF-A and HIF1α was examined after RNA isolation at the mRNA level by Real Time-PCR.

RESULTS

We have noted a significant correlation between the expression of selected TLR and VEGFR's and clinical stage as well as pathological grading of endometrial cancer.

CONCLUSIONS

Received correlations confirm a significant contribution of some TLR expression and the receptor for VEGF in the pathogenesis of epithelial endometrial cancer.

Injured Axons Instruct Schwann Cells to Build Constricting Actin Spheres to Accelerate Axonal Disintegration

After a peripheral nerve lesion, distal ends of injured axons disintegrate into small fragments that are subsequently cleared by Schwann cells and later by macrophages. Axonal debris clearing is an early step of the repair process that facilitates regeneration. We show here that Schwann cells promote distal cut axon disintegration for timely clearing. By combining cell-based and in vivo models of nerve lesion with mouse genetics, we show that this mechanism is induced by distal cut axons, which signal to Schwann cells through PlGF mediating the activation and upregulation of VEGFR1 in Schwann cells. In turn, VEGFR1 activates Pak1, leading to the formation of constricting actomyosin spheres along unfragmented distal cut axons to mediate their disintegration. Interestingly, oligodendrocytes can acquire a similar behavior as Schwann cells by enforced expression of VEGFR1. These results thus identify controllable molecular cues of a neuron-glia crosstalk essential for timely clearing of damaged axons.

Detection of circulating natural antibodies against CD25, MUC1, and VEGFR1 for early diagnosis of non-small cell lung cancer

We previously demonstrated that a deficiency of natural antibodies against CD25, Mucin 1 (MUC1), and vascular endothelial growth factor receptor 1 (VEGFR1) could contribute to high risk of non‐small cell lung cancer (NSCLC). This study was designed to investigate whether natural IgG antibodies against POU domain class 5 transcription factor 1 (POU5F1), tumor necrosis factor‐α (TNF‐α), and the combination of CD25, VEGFR1, and MUC1 could play an anti‐tumorigenic role against developing NSCLC. An ELISA was developed in‐house to examine plasma IgG against peptide antigens derived from POU5F1, TNF‐α, and a combination of peptide antigens derived from CD25, MUC1, and VEGFR1 in 211 patients with NSCLC and 200 healthy controls. Mann–Whitney U test demonstrated that plasma IgG levels for the combination of peptide antigens derived from CD25, MUC1, and VEGFR1 were significantly lower in NSCLC patients than control subjects (Z = −12.978, P < 0.001) although plasma levels of IgG antibodies for POU5F1 and TNFα were not significantly changed. The in‐house ELISA made with the CD25‐MUC1‐VEGFR1 combination had a sensitivity of 49.6% against a specificity of 95% to detect early‐stage NSCLC. In conclusion, natural antibodies against the combination of CD25, VEGFR1, and MUC1 may be an effective biomarker for early diagnosis of NSCLC.

γ-Secretase modulators exhibit selectivity for modulation of APP cleavage but inverse γ-secretase modulators do not

Background

γ-Secretase is a multiprotein protease that cleaves amyloid protein precursor (APP) and other type I transmembrane proteins. It has two catalytic subunits, presenilins 1 and 2 (PS1 and 2). In our previous report, we observed subtle differences in PS1- and PS2-mediated cleavages of select substrates and slightly different potencies of PS1 versus PS2 inhibition for select γ-secretase inhibitors (GSIs) on various substrates. In this study, we investigated whether γ-secretase modulators (GSMs) and inverse γ-secretase modulators (iGSMs) modulate γ-secretase processivity using multiple different substrates. We next used HEK 293T cell lines in which PSEN1 or PSEN2 was selectively knocked out to investigate processivity and response to GSMs and iGSMs.

Methods

For cell-free γ-secretase cleavage assay, recombinant substrates were incubated with CHAPSO-solubilized CHO or HEK 293T cell membrane with GSMs or iGSMs in suitable buffer. For cell-based assay, cDNA encoding substrates were transfected into HEK 293T cells. Cells were then treated with GSMs or iGSMs, and conditioned media were collected. Aβ and Aβ-like peptide production from cell-free and cell-based assay were measured by ELISA and mass spectrometry.

Result

These studies demonstrated that GSMs are highly selective for effects on APP, whereas iGSMs have a more promiscuous effect on many substrates. Surprisingly, iGSMs actually appear to act as like GSIs on select substrates. The data with PSEN1 or PSEN2 knocked out HEK 293T reveal that PS1 has higher processivity and response to GSMs than PS2, but PS2 has higher response to iGSM.

Conclusion

Collectively, these data indicate that GSMs are likely to have limited target-based toxicity. In addition, they show that iGSMs may act as substrate-selective GSIs providing a potential new route to identify leads for substrate-selective inhibitors of certain γ-secretase-mediated signaling events. With growing concerns that long-term β-secretase inhibitor is limited by target-based toxicities, such data supports continued development of GSMs as AD prophylactics.

Evaluation of 111In-DOTA-F56 peptide targeting VEGFR1 for potential non-invasive gastric cancer xenografted tumor mice Micro-SPECT imaging

Non-invasive imaging of vascular endothelial growth factor receptor 1 (VEGFR1) remains a great challenge in the early diagnosis of tumors, especially in gastric cancer. Here, we designed and evaluated a novel ¹¹¹In-DOTA-F56 peptide as a radioactive analogue of F56 (peptide WHSDMEWWYLLG) to bind VEGFR1. It was obtained by radiolabeling DOTA-F56 with ¹¹¹InCl₃ with 98% radiochemical purity and 1.4 ± 0.4 GBq/µmol specific activity. ¹¹¹In-DOTA-F56 was obtained by the reaction of DOTA-F56 (10 µg) with ¹¹¹InCl₃ in pH 4.0 sodium acetate buffer at 85 °C for 20 min. ¹¹¹In-DOTA-F56 shows good stability in 0.01 M Phosphate Buffered Saline (PBS) and 5% Human Serum Albumin (HSA). ¹¹¹In-DOTA-F56 has a high binding affinity for human gastric cancer BGC-823 cells. Bio-distribution studies of ¹¹¹In-DOTA-F56 were performed in nude mice xenografted with human gastric cancer BGC-823 cells and the results revealed tumor uptake accumulation. A blocking dose of DOTA-F56 significantly reduced the tumor uptake of ¹¹¹In-DOTA-F56. Tumors were observed with Micro-SPECT images, and the uptake in the tumor increased with time from 4 h to 24 h. The MIP of the Micro-SPECT also showed that the excess DOTA-F56 can specifically block ¹¹¹In-DOTA-F56 in a mouse tumor model. We successfully synthesized the ¹¹¹In-DOTA-F56 VEGFR1-targeted peptide as a non-invasive molecule with fine radiochemical properties. Micro-SPECT indicates tumor uptake, which can be further blocked by excess of the F56 peptide, indicating that ¹¹¹In-DOTA-F56 peptide has potential for early detection of VEGFR1 positive gastric cancer and is worthy of further clinical investigations.

Targeting signaling pathways of VEGFR1 and VEGFR2 as a potential target in the treatment of breast cancer

Tumor angiogenesis allows tumor cells to grow and migrate toward the bloodstream and initiate metastasis. The interactions of vascular endothelial growth factors (VEGF) A and B, as the important regulating factors for blood vessel growth, with VEGFR1 and VEGFR2 trigger angiogenesis process. Thus, preventing these interactions led to the effective blockade of VEGF/VEGFRs signaling pathways. In this study, the inhibitory effect of a 23-mer linear peptide (VGB4), which binds to both VEGFR1 and VEGFR2, on VEGF-stimulated Human Umbilical Vein Endothelial Cells (HUVECs) and highly metastatic human breast cancer cell MDA-MB-231 proliferation was examined using MTT assay. To assess the anti-migratory potential of VGB4, HUVECs and also MDA-MB-231 cells wound healing assay was carried out at 48 and 72 h. In addition, downstream signaling pathways of VEGF associated with cell migration and invasion were investigated by quantification of mRNA and protein expression using real-time quantitative PCR and western blot in 4T1 tumor tissues and MDA-MB-231 cells. The results revealed that VGB4 significantly impeded proliferation of HUVECs and MDA-MB-231 cells, in a dose- and time-dependent manner, and migration of HUVECs and MDA-MB-231 cells for a prolonged time. We also observed statistically significant reduction of the transcripts and protein levels of focal adhesion kinase (FAK), Paxillin, matrix metalloproteinase-2 (MMP-2), RAS-related C3 botulinum substrate 1 (Rac1), P21-activated kinase-2 (PAK-2) and Cofilin-1 in VGB4-treated 4T1 tumor tissues compared to controls. The protein levels of phospho-VEGFR1, phospho-VEGFR2, Vimentin, β-catenin and Snail were markedly decreased in both VGB4-treated MDA-MB-231 cells and VGB4-treated 4T1 tumor tissues compared to controls as evidenced by western blotting. These results, in addition to our previous studies, confirm that dual blockage of VEGFR1 and VEGFR2, due to the inactivation of diverse signaling mediators, effectively suppresses tumor growth and metastasis.

Expression of Diverse Angiogenesis Factor in Different Stages of the 4T1 Tumor as a Mouse Model of Triple-Negative Breast Cancer

Purpose: Triple-negative breast cancer (TNBC) is specified by high vascularity and repetitious metastasis. Although several studies have indicated that angiogenesis has an important role in invasive breast cancer, a suitable model of TNBC that can show the exact onset of angiogenesis factors still needs to be developed. The purpose of this study is to determine the expression level of angiogenesis factors in different clinical stages of the 4T1 tumor as TNBC mouse model.

Methods: Twenty mice were injected by the 4T1 cell line, and four mice selected as healthy controls. Following by tumor induction, the mice were randomly put into four groups, each contains four mice. Once the tumor volume reached to the early stage (<100 mm³), intermediate stage (100-300 mm³), advanced stage (300-500 mm³), and end stage (>500 mm³), they were removed by surgery. Then, the expression levels of Hif1α, VEGFR1, and VEGFR2 genes, as well as tumor markers of VEGF, bFGF and CD31, were evaluated by qPCR and immunohistochemistry (IHC) respectively. The statistical analysis was done by SPSS version 16.

Results: TNBC tumors were confirmed and multi-foci metastasis in the lung were seen. The mRNA and protein expression levels of the angiogenesis factors increased in the early stage and as the tumor grew, their expression level enhanced dramatically.

Conclusion: The 4T1 syngeneic mouse tumor may serve as an appropriate TNBC model for further investigation of the angiogenesis and therapies. Moreover, angiogenesis factors are induced before the advanced stage, and anti-angiogenesis therapy is necessary to be considered at the first line of treatment in TBNC.

VEGFR1-Targeted Contrast-Enhanced Ultrasound Imaging Quantification of Vasculogenic Mimicry Microcirculation in a Mouse Model of Choroidal Melanoma

Purpose

Investigate the involvement of vascular endothelial growth factor receptor 1 (VEGFR1) in vasculogenic mimicry (VM) formation in ocular melanoma, as well as whether or not VEGFR1-targeted contrast-enhanced ultrasound (CEUS) can evaluate and quantify VM perfusion and function in the ocular melanoma model.

Methods

The expression of VEGFR1 was examined using immunofluorescence, western blot, and quantitative polymerase chain reaction. VM networks were analyzed with tube formation and periodic acid Schiff staining. Targeted microbubbles (MBs) were constructed and used for targeted CEUS imaging in vivo. Comparisons were made in perfusion parameters of tumors between targeted and non-targeted CEUS imaging.

Results

VEGFR1 was highly expressed, and knockdown of VEGFR1 significantly decreased VM protein expression and disrupted VM formation in MUM-2B melanoma. VEGFR1-targeted MBs specifically bind to MUM-2B cell surfaces. CEUS with VEGFR1-targeted MBs showed significant imaging enhancement throughout the entire perfusion phase compared with CEUS with IgG MBs. VEGFR1-targeted imaging was able to detect a decrease in maximum intensity and mean transit time in VEGFR1 knockdown melanoma compared with control melanoma. The pathological VM patterns were consistent with VEGFR1-targeted CEUS findings.

Conclusions

VEGFR1 was responsible for VM network formation and was required for efficient choroidal melanoma tumor growth. This study shows that VEGFR1-targeted CEUS can track VM levels in animal models of ocular melanoma at morphological levels in vivo. This experiment is noninvasive and reproducible and indicates the possibility of real-time in vivo imaging technology for VM evaluation.

Translational Relevance

Based on our study results, VEGFR1 could prove to be a promising treatment that targets VM formation in choroidal melanoma. Our findings also suggest the potential use of VEGFR1-targeted CEUS for quantitative monitoring of VM processes at the molecular level in the future.

Oral Delivery of a Tetrameric Tripeptide Inhibitor of VEGFR1 Suppresses Pathological Choroid Neovascularization

Age-related macular degeneration (AMD) is the primary cause of blindness in advanced countries. Repeated intravitreal delivery of anti-vascular endothelial growth factor (VEGF) agents has represented an important advancement for the therapy of wet AMD with significative results in terms of blindness prevention and partial vision restore. Nonetheless, some patients are not responsive or do not attain significant visual improvement, intravitreal injection may cause serious complications and important side effects have been reported for the prolonged block of VEGF-A. In order to evaluate new anti-angiogenic strategies, we focused our attention on VEGF receptor 1 (VEGFR1) developing a specific VEGFR-1 antagonist, a tetrameric tripeptide named inhibitor of VEGFR 1 (iVR1). We have evaluated its anti-angiogenic activity in the preclinical model of AMD, the laser-induced choroid neovascularization (CNV). iVR1 is able to potently inhibit CNV when delivered by intravitreal injection. Surprisingly, it is able to significantly reduce CNV also when delivered by gavage. Our data show that the specific block of VEGFR1 in vivo represents a valid alternative to the block of VEGF-A and that the inhibition of the pathological neovascularization at ocular level is also possible by systemic delivery of compounds not targeting VEGF-A.

Early Post-stroke Activation of Vascular Endothelial Growth Factor Receptor 2 Hinders the Receptor 1-Dependent Neuroprotection Afforded by the Endogenous Ligand

Vascular endothelial growth factor (VEGF) has long been connected to the development of tissue lesion following ischemic stroke. Contradictory findings either situate VEGF as a promoter of large infarct volumes or as a potential attenuator of damage due to its well documented neuroprotective capability. The core of this discrepancy mostly lies on the substantial number of pleiotropic functions driven by VEGF. Mechanistically, these effects are activated through several VEGF receptors for which various closely related ligands exist. Here, we tested in an experimental model of stroke how the differential activation of VEGF receptors 1 and 2 would modify functional and histological outcomes in the acute phase post-ischemia. We also assessed whether VEGF-mediated responses would involve the modulation of inflammatory mechanisms and how this trophic factor acted specifically on neuronal receptors. We produced ischemic infarcts in adult rats by transiently occluding the middle cerebral artery and induced the pharmacological inhibition of VEGF receptors by i.c.v. administration of the specific VEGFR2 inhibitor SU1498 and the pan-VEGFR blocker Axitinib. We evaluated the neurological performance of animals at 24 h following stroke and the occurrence of brain infarctions analyzed at the gross metabolic and neuronal viability levels. We also assessed the induction of peripheral pro- and anti-inflammatory cytokines in the cerebrospinal fluid and blood and assessed the polarization of activated microglia. Finally, we studied the direct involvement of cortical neuronal receptors for VEGF with in vitro assays of excitotoxic damage. Preferential VEGFR1 activation by the endogenous ligand promotes neuronal protection and prevents the presentation of large volume infarcts that highly correlate with neurological performance, while the concomitant activation of VEGFR2 reduces this effect, even in the presence of exogenous ligand. This process partially involves the polarization of microglia to the state M2. At the cellular level, neurons also responded better to the preferential activation of VEGFR1 when challenged to N-methyl-D-aspartate-induced excitotoxicity. Endogenous activation of VEGFR2 hinders the neuroprotective mechanisms mediated by the activation of VEGFR1. The selective modulation of these concurrent processes might enable the development of therapeutic approaches that target specific VEGFR1-mediated signaling during the acute phase post-stroke.

Synergistic Anti-Angiogenic Effects Using Peptide-Based Combinatorial Delivery of siRNAs Targeting VEGFA, VEGFR1, and Endoglin Genes

Angiogenesis is a process of new blood vessel formation, which plays a significant role in carcinogenesis and the development of diseases associated with pathological neovascularization. An important role in the regulation of angiogenesis belongs to several key pathways such as VEGF-pathways, TGF-β-pathways, and some others. Introduction of small interfering RNA (siRNA) against genes of pro-angogenic factors is a promising strategy for the therapeutic suppression of angiogenesis. These siRNA molecules need to be specifically delivered into endothelial cells, and non-viral carriers modified with cellular receptor ligands can be proposed as perspective delivery systems for anti-angiogenic therapy purposes. Here we used modular peptide carrier L1, containing a ligand for the CXCR4 receptor, for the delivery of siRNAs targeting expression of VEGFA, VEGFR1 and endoglin genes. Transfection properties of siRNA/L1 polyplexes were studied in CXCR4-positive breast cancer cells MDA-MB-231 and endothelial cells EA.Hy926. We have demonstrated the efficient down-regulation of endothelial cells migration and proliferation by anti-VEGFA, anti-VEGFR1, and anti-endoglin siRNA-induced silencing. It was found that the efficiency of anti-angiogenic treatment can be synergistically improved via the combinatorial delivery of anti-VEGFA and anti-VEGFR1 siRNAs. Thus, this approach can be useful for the development of therapeutic angiogenesis inhibition.

The role of vascular endothelial growth factor receptor 1 tyrosine kinase signaling in bleomycin-induced pulmonary fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a lethal lung disease with a poor prognosis. Fibroblast proliferation amplifies extracellular matrix deposition and increases angiogenesis. Vascular endothelial growth factor (VEGF) is one of the most potent angiogenic factors. VEGF interacts with VEGF receptors (VEGFR1 and VEGFR2). A previous study showed that VEGFR1 tyrosine kinase (TK) signaling induced blood flow recovery mediated by bone marrow (BM)-derived stem cells. We hypothesized that VEGFR1-TK signaling might be related to pulmonary fibrosis.

MATERIAL AND METHODS

Six-week-old male C57Bl/6 wild-type (WT) mice and VEGFR1 TK knockout mice (TKKO mice) were treated with a single intratracheal injection of bleomycin (BLM; 0.1 μg in 50 μl saline) or vehicle (saline; 50 μl). Lung fibrosis was evaluated by histology, real-time PCR and ELISA for pro-fibrotic factors, and assessment of lung mechanics.

RESULTS

The fibrotic area in the lung and the lung elastance were significantly reduced in TKKO mice (P < 0.01). The expression of the fibrosis-related factors type I collagen, S100A4, and transforming growth factor (TGF)-β was also significantly reduced in TKKO mice on day 21 after BLM injection. TKKO mice also had significantly lower levels of stromal cell-derived factor (SDF)-1 in the lungs and plasma on days 14 and 21 after BLM treatment (P < 0.05). Moreover, the expression of C-X-C chemokine receptor type 7 (CXCR7) and CXCR4, the receptors for SDF-1, was also suppressed in TKKO mice. Immunohistochemical analysis showed that treatment with a CXCR4 antibody decreased the accumulation of VEGFR1⁺ cells in the lung in WT mice but not in TKKO mice.

CONCLUSION

These results suggest that VEGFR1 TK signaling promotes BLM-induced pulmonary fibrosis by activating the SDF-1/CXCR4 axis in infiltrating VEGFR1⁺ cells.

Suppression of migratory and metastatic pathways via blocking VEGFR1 and VEGFR2

BACKGROUND

Vascular endothelial growth factor (VEGF) A and B are endothelial cell mitogens whose ligation to VEGFR1/VEGFR2 drives tumor angiogenesis and metastasis, and epithelial-mesenchymal transition (EMT). Blockade of these signaling axes could be obtained by disturbing the interactions between VEGFA and/or VEGFB with VEGFR1 and/or VEGFR2.

METHODS

A 14-mer peptide (VGB) that recognizes both VEGFR1 and VEGFR2 were investigated for its inhibitory effects on the VEGF-induced proliferation and migration using MTT and scratch assay, respectively. Downstream signaling pathways were also assessed by quantitative estimation of gene and protein expression using real-time PCR and immunohistochemistry (IHC).

RESULTS

We investigated the inhibitory effects of VGB on downstream mediators of metastasis, including epithelial-cadherin (E-cadherin), matrix metalloprotease-9 (MMP-9), cancer myelocytomatosis (c-Myc), and nuclear factor-κβ (NF-κβ), and migration, comprising focal adhesion kinase (FAK) and its substrate Paxilin. VGB inhibited the VEGF-induced proliferation of human umbilical vein endothelial cells (HUVECs), 4T1 and U87 cells in a time- and dose-dependent manner and migration of HUVECs. Based on IHC analyses, treatment of 4T1 mammary carcinoma tumor with VGB led to the suppression of p-AKT, p-ERK_1/2, MMP-9, NF-κβ, and activation of E-cadherin compared with PBS-treated controls. Moreover, quantitative real-time PCR analyses of VGB-treated tumors revealed the reduced expression level of FAK, Paxilin, NF-κβ, MMP-9, c-Myc, and increased expression level of E-cadherin compared to PBS-treated controls.

CONCLUSIONS

Our results demonstrated that simultaneous blockade of VEGFR1/VEGFR2 is an effective strategy to fight solid tumors by targeting a wider range of mediators involved in tumor angiogenesis, growth, and metastasis.

Computational Modeling to Quantify the Contributions of VEGFR1, VEGFR2, and Lateral Inhibition in Sprouting Angiogenesis

Sprouting angiogenesis is a necessary process in regeneration and development as well as in tumorigenesis. VEGF-A is the main pro-angiogenic chemoattractant and it can bind to the decoy receptor VEGFR1 or to VEGFR2 to induce sprouting. Active sprout cells express Dll4, which binds to Notch1 on neighboring cells, in turn inhibiting VEGFR2 expression. It is known that the balance between VEGFR2 and VEGFR1 determines tip selection and network architecture, however the quantitative interrelationship of the receptors and their interrelated balances, also with relation to Dll4-Notch1 signaling, remains yet largely unknown. Here, we present an agent-based computer model of sprouting angiogenesis, integrating VEGFR1 and VEGFR2 in a detailed model of cellular signaling. Our model reproduces experimental data on VEGFR1 knockout. We show that soluble VEGFR1 improves the efficiency of angiogenesis by directing sprouts away from existing cells over a wide range of parameters. Our analysis unravels the relevance of the stability of the active notch intracellular domain as a dominating hub in this regulatory network. Our analysis quantitatively dissects the regulatory interactions in sprouting angiogenesis. Because we use a detailed model of intracellular signaling, the results of our analysis are directly linked to biological entities. We provide our computational model and simulation engine for integration in complementary modeling approaches.

Effects of VEGFR1+ hematopoietic progenitor cells on pre-metastatic niche formation and in vivo metastasis of breast cancer cells

The pre-metastatic niche has been shown to play a critical role in tumor metastasis, and its formation is closely related to the tumor microenvironment. However, the underlying molecular mechanisms remain unclear. In the present study, we successfully established a mouse model of lung metastasis using luciferase-expressing MDA-MB-435s cells. In this model, recruitment of vascular endothelial growth factor receptor-1 (VEGFR1)⁺CD133⁺ hematopoietic progenitor cells (HPCs) was gradually increased in lung but gradually decreased after the formation of tumor colonies in lung. We also established a highly metastatic MDA-MB-435s (MDA-MB-435s-HM) cell line from the mouse model. Changes in protein profiles in different culture conditions were investigated by protein microarray analysis. The levels of CXC chemokine ligand 16, interleukin (IL)-2Rα, IL-2Rγ, matrix metalloproteinase (MMP)-1, MMP-9, platelet-derived growth factor receptor (PDGFR)-α, stromal cell-derived factor (SDF)-1α, transforming growth factor (TGF)-β, platelet endothelial cell adhesion molecule (PECAM)-1 and vascular endothelial (VE)-cadherin were significantly greater (> fivefold) in the culture medium from MDA-MB-435s-HM cells than in that from MDA-MB-435s cells. Moreover, the levels of MMP-9, PDGFR-α, and PECAM-1 were significantly greater in the co-culture medium of MDA-MB-435s-HM cells and CD133⁺ HPCs than in that from MDA-MB-435s-HM cells. Differentially expressed proteins were validated by enzyme-linked immunosorbent assay, and expression of their transcripts was confirmed by quantitative real-time polymerase chain reaction. Moreover, inhibition of MMP-9, PDGFR-α, and PECAM-1 by their specific inhibitors or antibodies significantly decreased cell migration, delayed lung metastasis, and decreased recruitment of VEGFR1⁺CD133⁺ HPCs into lung. Intra-hepatic growth of HPCs enhanced the invasive growth of MDA-MB-435s-HM cells in the liver. Our data indicate that VEGFR1⁺CD133⁺ HPCs contribute to lung metastasis.

Dihydroartemisinin enhances VEGFR1 expression through up-regulation of ETS-1 transcription factor

Angiogenesis is required for tumor growth. Dihydroartemisinin (DHA), a the effective anti-malarial derivative of artemisinin, demonstrated potent anti-angiogenic activities that closely related to the regulation of vascular endothelial growth factor (VEGF) signaling cascade. VEGF receptor 1 (VEGFR1), a receptor in endothelial cells (ECs), coordinately regulate angiogenic activity triggered by ligand-receptor binding. Here we aimed to explore the effects of DHA on VEGFR1 expression in ECs. We found that DHA significantly increases VEGFR1 expression in human umbilical vein endothelial cells (HUVECs). In addition, DHA significantly upregulates the level of V-Ets Avian Erythroblastosis Virus E26 Oncogene Homolog 1 (ETS-1), a transcriptional factor which binds to the human VEGFR1 promoter. ChIP assay showed that DHA increases ETS-1 binding to the -52 ETS motif on the VEGFR1 promoter. Knockdown of ETS-1 by RNA interference abolished DHA-induced increase of VEGFR1 expression. Taken together, we demonstrated that DHA elevates VEGFR1 expression via up-regulation of ETS-1 transcription in HUVECs.

Loss of Caveolin-1 in Metastasis-Associated Macrophages Drives Lung Metastatic Growth through Increased Angiogenesis

Although it is well established that tumor-associated macrophages take part in each step of cancer progression, less is known about the distinct role of the so-called metastasis-associated macrophages (MAMs) at the metastatic site. Previous studies reported that Caveolin-1 (Cav1) has both tumor-promoting and tumor-suppressive functions. However, the role of Cav1 in bone-marrow-derived cells is unknown. Here, we describe Cav1 as an anti-metastatic regulator in mouse models of lung and breast cancer pulmonary metastasis. Among all the recruited inflammatory cell populations, we show that MAMs uniquely express abundant levels of Cav1. Using clodronate depletion of macrophages, we demonstrate that macrophage Cav1 signaling is critical for metastasis and not for primary tumor growth. In particular, Cav1 inhibition does not affect MAM recruitment to the metastatic site but, in turn, favors angiogenesis. We describe a mechanism by which Cav1 in MAMs specifically restrains vascular endothelial growth factor A/vascular endothelial growth factor receptor 1 (VEGF-A/VEGFR1) signaling and its downstream effectors, matrix metallopeptidase 9 (MMP9) and colony-stimulating factor 1 (CSF1).

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Macrophage Cav1 signaling is critical for restraining lung metastatic growth

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Cav1 deletion in macrophages favors angiogenesis at the lung metastatic site

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Cav1 suppresses VEGF-A/VEGFR1 activity and its downstream effectors, MMP9 and CSF1

VEGF vascularization pathway in human intervertebral disc does not change during the disc degeneration process

Objective

During degeneration of the intervertebral disc ingrowth of blood vessels and nerves into the disc are associated with back pain. Vascular endothelial growth factors promote vasculogenesis by binding to the membrane vascular endothelial growth factor receptor 1, while shorter soluble forms of this receptor can inhibit vascularization. We hypothesized that membrane and soluble receptor forms might change between stages of intervertebral disc degeneration.

Results

Expression of soluble and membrane forms of vascular endothelial growth factor receptor 1 in human degenerated intervertebral discs and healthy bovine caudal discs was assessed by qRT-PCR and immunoblot. Comparative microarray meta-analysis across disc degeneration grades showed that membrane and soluble forms of this receptor, together with other components of classic vascularization pathways, are constitutively expressed across human disc degeneration stages. Contrary to our hypothesis, we observed that expression of the classic vascularization pathway is stable across degeneration stages and we assume that soluble vascular endothelial growth factor receptor 1 does not contribute to prevent disc degeneration. However, we observed increased expression levels of genes involved in alternative vascularization signalling pathways in severely degenerated discs, suggesting that abnormal vascularization is part of the pathological progression of disc degeneration.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3441-3) contains supplementary material, which is available to authorized users.

Antibodies to Signaling Molecules and Receptors in Alzheimer's Disease are Associated with Psychomotor Slowing, Depression, and Poor Visuospatial Function

BACKGROUND

Alzheimer's disease (AD) is associated with several antibodies as well as signaling molecules and receptors. These may be detrimental in the presence of a disrupted blood-brain barrier (BBB).

OBJECTIVE

To investigate whether the levels of antibodies toward 33 signaling molecules involved in neurotransmitter, vascular, and immune functions were associated with AD and, within the AD group; cognitive function and mood.

METHODS

Antibodies in sera from patients with mild AD [(n = 91) defined as a Mini-Mental State Examination ≥ 20 or a Clinical Dementia Rating Scale≤1] and healthy controls (n = 102) were measured with enzyme-linked immunosorbent assays. Levels in AD and controls were compared by Mann-Whitney test. In the AD group, associations between antibodies and psychometric test scores were analyzed by robust regression. The false discovery threshold was set to 0.05.

RESULTS

Antibodies to serotonin receptors [5-HT2AR (effect size (r) = 0.21, p = 0.004), 5-HT2CR (r = 0.25, p = 0.0005) and 5-HT7R (r = 0.21, p = 0.003)], vascular endothelial growth factor receptor 1 [VEGFR1 (r = 0.29, p < 0.001)] and immune-receptors (Stabilin-1 (r = 0.23, p = 0.001) and C5aR1 (r = 0.21, p = 0.004) were higher in AD. Psychomotor speed was associated with D1R-abs (β 0.49, p < 0.001), depression with ETAR-abs (β 0.31, p < 0.001), and visuospatial function with 5-HT1AR-abs (β 0.27, p = 0.004) despite similar antibody levels compared to controls.

CONCLUSIONS

Antibody levels to VEGFR1, serotonergic receptors, and receptors in the immune system were increased in AD. Antibodies at similar levels as in controls were associated cognitive dysfunction and depression in AD.

Development of a novel albumin-based and maleimidopropionic acid-conjugated peptide with prolonged half-life and increased in vivo anti-tumor efficacy

Angiogenesis plays a critical role in tumor aggressiveness, and a lot of anti-angiogenic agents have been used in clinical therapy. The therapeutic efficacy of peptides are generally restricted by the short in vivo life-time, thus, we were interested in developing a novel albumin-based and maleimidopropionic acid-conjugated peptide to prolong the half-life and improve the anti-tumor effect.

Methods: We developed a peptide F56 with a maleimidopropionic acid (MPA) at the C-terminal (denoted as F56-CM), which allows immediate and irreversible conjugation with serum albumin. Biological property and anti-tumor activity of F56-CM were evaluated in vitro and in vivo.

Results: We showed that F56-CM reduced migration and tube formation of endothelial cells in vitro and inhibited the generation of subintestinal vessels (SIV) in zebrafish embryos in vivo. F56-CM inhibited vascular endothelial growth factor (VEGF) induced phosphorylation of VEGFR1 and activation of the PI3K-AKT axis. Furthermore, F56-CM rapidly conjugated with albumin upon intravenous injection and extended the biological half-life of F56 from 0.4249 h to 6.967 h in rats. Compared with F56, F56-CM exhibited stronger anti-tumor activity on both BGC-823 gastric cancer and HT-29 colon cancer xenografts in nude mice, and the statistical difference was remarkable. More significantly, the efficacy of F56-CM inhibiting lung metastasis of BGC-823 cells was also better than that of F56. The inhibition rates were 62.1% and 78.9% for F56 and F56-CM respectively when administrated every day, and 43.8% and 63.1% when administrated every four days at equal dose.

Conclusions: Taken together, our results demonstrated that F56-CM has considerable potential for cancer therapy.

Lymphatics-associated genes are downregulated at transcription level in non-small cell lung cancer

The present study aimed to verify a possibility of ongoing lymphangiogenesis in non-small cell lung cancer (NSCLC) via examination of mRNA levels of a number of lymphangiogenesis-associated genes in tumors. It was hypothesized that transcriptional activation of these genes would occur in tumors that stimulate new lymphatic vessel formation. The study was performed on 140 pairs of fresh-frozen surgical specimens of cancer and unaffected lung tissues derived from NSCLC stage I-IIIA patients. mRNA levels were evaluated with the reverse transcription-quantitative polymerase chain reaction method and expressed as fold change differences between the tumor and normal tissues. Possible associations between expression and patient clinicopathological characteristics and survival were analyzed. In the NSCLC tissue samples, vascular endothelial growth factor (VEGF) C, VEGFD, VEGFR3, VEGFR2, VEGFR1, lymphatic vessel endothelial hyaluronan receptor 1, integrin subunit α 9, FOX2, neuropilin 2, fibroblast growth factor 2 genes were significantly downregulated (P<0.001 for all) compared with matched normal lung tissues, whereas mRNA levels for VEGFA, spleen associated tyrosine kinase, podoplanin, and prospero homeobox 1 genes were similar in both tissues. Neither lymph node status, nor disease pathological stage influenced expression, whereas more profound suppression of gene activities appeared to occur in squamous cell carcinomas compared with adenocarcinomas. The VEGFR1 mRNA expression level was significantly connected with patient survival in the univariate analysis, and was an independent prognostic factor for overall survival in the multivariate Cox's proportional hazards model (HR 2.103; 95% confidence interval: 1.005-4.401; P=0.049). The results support a hypothesis of absence of new lymphatic vessel formation inside growing NSCLC tumor mass, however do not exclude a possibility of lymphangiogenesis in narrow marginal tumor parts.

An optimized method using peptide arrays for the identification of in vitro substrates of lysine methyltransferase enzymes

While a number of post-translational modifications (PTM), such as phosphorylation and ubiquitination, have been extensively studied, lysine methylation is emerging as an important PTM with implications in a growing number of diverse cellular processes. To date, there are approximately 5000 identified methylation sites on non-histone proteins, and as the methyllysine proteome expands it becomes important to identify the lysine methyltransferase enzymes responsible for each methylation event. The use of peptide SPOT methylation assay has proven to be a useful in the identification and validation of novel substrates for lysine methyltransferase enzymes as it uses a weak beta emitter coupled with fluorography to detect methylation events. The method described in this paper provides improvements to the typical protocol for this assay, as a highly sensitive tritium assay can be developed with less radioactivity than previously described. This protocol provides an inexpensive alternative to weak beta signal enhancer sprays and washes for use in lysine methylation peptide SPOT arrays, and a simple open-source method for array quantification.

Blood vessel anastomosis is spatially regulated by Flt1 during angiogenesis

Blood vessel formation is essential for vertebrate development and is primarily achieved by angiogenesis - endothelial cell sprouting from pre-existing vessels. Vessel networks expand when sprouts form new connections, a process whose regulation is poorly understood. Here, we show that vessel anastomosis is spatially regulated by Flt1 (VEGFR1), a VEGFA receptor that acts as a decoy receptor. In vivo, expanding vessel networks favor interactions with Flt1 mutant mouse endothelial cells. Live imaging in human endothelial cells in vitro revealed that stable connections are preceded by transient contacts from extending sprouts, suggesting sampling of potential target sites, and lowered Flt1 levels reduced transient contacts and increased VEGFA signaling. Endothelial cells at target sites with reduced Flt1 and/or elevated protrusive activity were more likely to form stable connections with incoming sprouts. Target cells with reduced membrane-localized Flt1 (mFlt1), but not soluble Flt1, recapitulated the bias towards stable connections, suggesting that relative mFlt1 expression spatially influences the selection of stable connections. Thus, sprout anastomosis parameters are regulated by VEGFA signaling, and stable connections are spatially regulated by endothelial cell-intrinsic modulation of mFlt1, suggesting new ways to manipulate vessel network formation.

[Analysis of VEGF-A/VEGFR1/VEGFR2 gene expression in patients with myelodysplastic syndrome]

AIM

To assess the significance of gene expression of the vascular endothelial growth factor-A (VEGF-A) and its interacting receptors VEGFR1 and VEGFR2 as potential diagnostic and prognostic molecular markers in patients with myelodysplastic syndrome (MDS).

MATERIAL AND METHODS

A real time polymerase chain reaction (RT-PCR) assay was used to investigate the gene expression of VEGF-A, VEGFR1, and VEGFR2 in the mononuclear cell fractions obtained from 24 patients with MDS.

RESULTS

The expression of the 3 genes was identified in all the patients examined. There was the highest expression level of the VEGF-A gene (p<0.0001), whereas the expression of the VEGFR1 gene was higher than that of the VEGFR2 gene (p<0.001). The expression of the VEGF-A gene proved to be higher in patients at a higher risk of acute leukemia and positively correlated with the expression levels of the VEGFR1 gene (p<0.05) rather than that of the VEGFR2 gene. At the same time, patients with higher VEGFR1 gene expression had significantly lower overall survival rates (r=-0.5; p<0.05). Patients with intermediate-2 or high-risk acute leukemia showed an increase in the average expression levels of VEGF-A and VEGFR1 and a reduction in VEGFR2 expression.

CONCLUSION

This investigation revealed correlations between the number of blast cells in patients with MDS and the expression levels of the VEGF-A gene and between the overall survival of patients with MDS and the expression levels of the VEGFR1 gene rather than those of the VEGF-A and VEGFR2 genes.

Study of natural IgG antibodies against vascular endothelial growth factor receptor 1 in hepatocellular carcinoma

Natural antibodies have been found to have anti-tumorigenic function. This study was designed to investigate whether natural IgG antibodies against vascular endothelial growth factor receptor 1 (VEGFR1) could suppress the growth of hepatocellular carcinoma (HCC) cells. Three HCC cell lines and A549 lung cancer cells were used for this study. They were grown, respectively, with human plasma positive or negative for anti-VEGFR1 IgG. Cell viability, apoptosis and VEGFR1 gene expression were examined. Three patients with HCC were recruited for a case study. The results showed that plasma anti-VEGFR1 IgG significantly inhibited the proliferation of all three HCC cell lines but not A549 cell line; the proportions of apoptotic cells were significantly higher in HCC cells treated with anti-VEGFR1 IgG positive plasma than those treated with IgG negative plasma. The expression of the VEGFR1 gene was significantly higher in HCC cells than A549 cells. Of three HCC patients who received transfusion of anti-VEGFR1 IgG positive plasma, two cases with stage B showed a good response to the treatment but one with distant metastasis did not. Human plasma IgG against VEGFR1 may be a promising agent for anti-HCC therapy.

Meta-analysis on the association of VEGFR1 genetic variants with sunitinib outcome in metastatic renal cell carcinoma patients

VEGFR1 rs9582036 and rs9554320 were previously reported the association with sunitinib progression-free survival (PFS) and overall survival (OS) in patients with metastatic renal cell carcinoma (mRCC). Hereafter, the association of both single nucleotide polymorphisms (SNPs) with PFS/OS was confirmed in two independent mRCC cohorts. The aim of the current study was to validate the associations of both SNPs with sunitinib outcome in three independent well-characterized cohorts (SUTOX, CCF and SOGUG) including 286 sunitinib-treated mRCC patients, as well as to perform a meta-analysis of current and published data combined. We found that rs9582036 and rs9554320 showed a significant association with sunitinib PFS in the CCF cohort (HR: 0.254, 95%CI: 0.092-0.703; P=0.008 and HR: 0.430, 95%CI: 0.200-0.927; P=0.031, respectively). Patients with the variant genotype of rs9582036 and rs9554320 had a shorter median PFS. No significant association of both SNPs with sunitinib PFS or OS was detected in either the SUTOX or SOGUG cohort. After the combination of all available data into a meta-analysis, the association of both SNPs with sunitinib PFS or OS did not achieve the threshold for statistical significance. Our findings suggest that, although VEGFR1 rs9582036 and rs9554320 are involved in sunitinib therapy outcome, its clinical use as biomarkers for prediction of sunitinib outcome in mRCC patients is limited, due to inconsistent findings when analyzing all existing studies together.

[The growth factor of endothelium of vessels and its receptors type I and II in blood serum in patients with kidney cancer: clinical morphological correlations.]

The progress in treatment of kidney cancer is related to application of anti-angiogenic medications. Therefore, investigation and searching for new molecular markers characterizing its angiogenic activity is actual still. The purpose of study is to compare VEGF, VEGFR1 and VEGFR2 in blood serum of healthy people, patients with cancer and benign tumors of kidney and to analyze their relationship with main clinical morphological characteristics of neoplasms. The study sampling consisted of 94 patients with cancer and 10 patients with benign tumors of kidney. The control group included 80 individuals. The concentration of analyzed proteins was determined using QuantikineТ (R&D Systems, USA), a reagents' kit for direct immune enzyme analysis. The content of VEGF, VEGFR1 and VEGFR2 in blood serum of patients with cancer of kidney was reliably higher than in control group. The level of VEGF also was increased in patients with benign tumors. Under threshold level of VEGF of 365 pg/ml the diagnostic sensitivity of detection of primary cancer of kidney amounted to 67% and specificity - 70%. The stage of disease and T and N indices were correlated only with VEGFR1 level. The relationship between level of markers and histological structure and degree of differentiation of cancer of kidney was not established. Therefore, VEGF and its receptors have a limited diagnostic value under cancer of kidney but they can be applied for monitoring and prognosis of efficiency of anti-angiogenic therapy.

Validation of VEGFR1 rs9582036 as predictive biomarker in metastatic clear-cell renal cell carcinoma patients treated with sunitinib

OBJECTIVES

To validate vascular endothelial growth factor receptor-1 (VEGFR1) single nucleotide polymorphism (SNP) rs9582036 as a potential predictive biomarker in metastatic clear-cell renal cell carcinoma (m-ccRCC) patients treated with sunitinib.

MATERIALS AND METHODS

m-ccRCC patients receiving sunitinib as first-line targeted therapy were included. We assessed response rate (RR), progression-free survival (PFS), overall survival (OS), and clinical and biochemical parameters associated with outcome. We genotyped five VEGFR1 SNPs: rs9582036, rs7993418, rs9554320, rs9554316 and rs9513070. Association with outcome was studied by univariate analysis and by multivariate Cox regression. Additionally, we updated survival data of our discovery cohort as described previously.

RESULTS

Sixty-nine patients were included in the validation cohort. rs9582036 CC-carriers had a poorer PFS (8 vs 12 months, P = 0.02) and OS (11 vs 27 months, P = 0.003) compared to AC/AA-carriers. rs7993418 CC-carriers had a poorer OS (8 vs 24 months, P = 0.004) compared to TC/TT-carriers. rs9554320 AA-carriers had a poorer RR (0% vs 53%, P = 0.009), PFS (5 vs 12 months, P = 0.003) and OS (10 vs 25 months, P = 0.004) compared to AC/CC-carriers. When pooling patients from the discovery cohort, as described previously (n = 88), and the validation cohort, in the total series of 157 patients, rs9582036 CC-carriers had a poorer RR (8% vs 49%, P = 0.004), PFS (8 vs 14 months, P = 0.003) and OS (13 vs 30 months, P = 0.0004) compared to AC/AA-carriers. Unfavorable prognostic markers at start of sunitinib were well balanced between rs9582036 CC- and AC/AA-carriers.

CONCLUSION

VEGFR1 rs9582036 is a candidate predictive biomarker in m-ccRCC-patients treated with sunitinib.

Profiling of Vascular Endothelial Growth Factor Receptor Heterogeneity Identifies Protein Expression-defined Subclasses of Human Non-small Cell Lung Carcinoma

BACKGROUND

the vascular endothelial growth factor (VEGF) pathway plays a prominent role in the growth and progression of human cancer, including non-small cell lung carcinoma (NSCLC). The key mediators of VEGF signaling are a family of related receptor tyrosine kinases that include VEGFR1, VEGFR2, and VEGFR3. The relative expression levels, activity, and cross-talk among these receptors may contribute to response of NSCLC to anti-angiogenic therapies, and a better systematic, translatable approach to categorizing tumors is needed.

MATERIALS AND METHODS

We comparatively evaluated immunohistochemical expression of the three VEGFRs in archival primary NSCLC tissues (n=96).

RESULTS

VEGFR1 and VEGFR2 were localized both in vessels and tumor cells, while VEGFR3 was only localized in tumor vessels. A set of eight VEGFR staining subclasses were identified: Triple VEGFR positive (n=11, 11.5%), VEGFR1 predominant (n=22, 22.9%), VEGFR2 predominant (n=9, 9.4%), VEGFR3 predominant (n=3, 3.1%), VEGFR1/2 predominant (13, 13.5%), VEGFR1/3 predominant (2, 2.1%), VEGFR2/3 predominant (n=8, 8.3%), and triple VEGFR negative (n=28, 29.2%). An objective categorization based on K-means clustering revealed four clusters, three of which showed high VEGFR2 compared to VEGFR3 (30.7% of cases), cases high in both VEGFR2 and VEGFR3 (18.2%), and cases that were negative/low for both VEGFR2 and VEGFR3 (45.4%). A positive association between VEGFR2 and VEGFR3 was found, however no associations were observed between VEGFR1 and VEGFR2, nor VEGFR1 and VEGFR3.

CONCLUSION

The proposed subclasses of NSCLC are an approach for complementing lines of investigation of anti-angiogenic therapies beginning with systematic characterization of the disease.

A bi-functional antibody-receptor domain fusion protein simultaneously targeting IGF-IR and VEGF for degradation

Bi-specific antibodies (BsAbs), which can simultaneously block 2 tumor targets, have emerged as promising therapeutic alternatives to combinations of individual monoclonal antibodies. Here, we describe the engineering and development of a novel, human bi-functional antibody-receptor domain fusion molecule with ligand capture (bi-AbCap) through the fusion of the domain 2 of human vascular endothelial growth factor receptor 1 (VEGFR1) to an antibody directed against insulin-like growth factor - type I receptor (IGF-IR). The bi-AbCap possesses excellent stability and developability, and is the result of minimal engineering. Beyond potent neutralizing activities against IGF-IR and VEGF, the bi-AbCap is capable of cross-linking VEGF to IGF-IR, leading to co-internalization and degradation of both targets by tumor cells. In multiple mouse xenograft tumor models, the bi-AbCap improves anti-tumor activity over individual monotherapies. More importantly, it exhibits superior inhibition of tumor growth, compared with the combination of anti-IGF-IR and anti-VEGF therapies, via powerful blockade of both direct tumor cell growth and tumor angiogenesis. The unique "capture-for-degradation" mechanism of the bi-AbCap is informative for the design of next-generation bi-functional anti-cancer therapies directed against independent signaling pathways. The bi-AbCap design represents an alternative approach to the creation of dual-targeting antibody fusion molecules by taking advantage of natural receptor-ligand interactions.