VEGFR2 Concentration Research Articles

VEGFA, VEGFR1, VEGFR2 serum and cerebrospinal fluid concentration in patients with acute leukemia

Background. Vascular endothelial growth factor A (VEGFA) is one of the most important factors for regulation of hematopoietic stem cells differentiation. It is involved in leukemogenesis and central nervous system (CNS) damage in acute leukemia. According to the literature, the VEGFA production by blast cells is increased, but the values of serum concentration and the associations with CNS involvement are contradictory.Aim. evaluate the VEGFA, VEGFR1, VEGFR2 concentration in serum and cerebrospinal fluid of patient with different types of acute leukemia in disease onset and during treatment.Materials and methods. The concentration of VEGFA in serum and cerebrospinal fluid was studied in 74 primary patients with acute leukemia. The comparison group consisted of 67 healthy donors. VEGFR1, VEGFR2 were studied in serum and cerebrospinal fluid in 34 patients at the onset of the disease. The comparison group consisted of 10 healthy donors. For the analysis, an enzyme immunoassay was used on a semi-automatic Personal Lab analyzer (Adaltis) and Affymetrix eBioscience human VEGF-A Platinum ELISA reagents.Results. Serum VEGFA concentration was statistically significantly lower in acute leukemia patients than that of donors (median 149.78 and 432.19 pg/ml respectively; p <0.0001). Factor deficiency was significantly more pronounced in patients with blastemia (p <0.015). During antitumor therapy, there was a tendency to increase the amount of the factor in the blood serum. Serum concentration of soluble VEGFR2 was also lower in patients than that of donors (6949.9 and 8795.9 pg/ml respectively; p = 0.0026). For concentration of VEGFR1 such deviations were not found. The concentrations of VEGFR1 and VEGFR2 in serum were higher than in cerebrospinal fluid (p <0.0001), while VEGFR1 showed a positive correlation between serum and cerebrospinal fluid concentrations. the concentration of VEGFR1 in the cerebrospinal fluid was significantly lower in patients with B-lymphoblastic leukemia/lymphoma compared to other types of leukemia.Conclusion. the concentration of VEGFA in serum decreases in patients with blastemia, this may indicate a lack of secretion and excessive consumption of the factor by blast cells with a decrease in the proportion of leukocytes that normally secrete the factor. In the cerebrospinal fluid, the concentrations of VEGFR1 and VEGFR2 are lower than in serum, with the lowest values being found in patients with B-lymphoblastic leukemia/lymphoma, but no relationship with the development of CNS involvement was found.

Seasonal and nutritional changes in the short form of the leptin receptor expression and VEGF system in the choroid plexus, arcuate nucleus, and anterior pituitary in MTS-leptin and resistin-treated sheep

The short form of the leptin receptor (LeptRa) plays a key role in the transport of leptin to the central nervous system (CNS). Here, MTS-leptin and recombinant ovine (ro) leptin-mediated expression of LeptRa and VEGFA and VEGFR2 concentration in selected hypothalamic nuclei, choroid plexus (ChP), and anterior pituitary (AP) were analyzed considering the photoperiod and acute-fasting (experiment 1), and nutritional status (experiment 2) of ewes. In experiment 1, 60 sheep were fed normally or fasted for 72 h and received one injection of saline, MTS-leptin, or roleptin 1 h prior to euthanasia. LeptRa mRNA transcript levels and VEGF system protein concentrations were detected in the ARC, ChP predominantly in the SD, and AP for the LD without detection of LeptRa in the POA and VMH/DMH. In experiment 2, an altered diet for 5 months created lean or fat sheep. Twenty sheep were divided into four groups: the lean and fat groups were given saline, while the lean-R and fat-R groups received resistin 1 h prior to euthanasia. Changes in adiposity influenced the lowering effect of resistin on the expression of LeptRa and VEGF system protein concentrations. Overall, both photoperiodic and nutritional signals influence the effects of MTS-leptin/roleptin and resistin-mediated leptin transport to the CNS via LeptRa. Resistin seems to be another adipokine involved in the adaptive/pathological phenomenon of leptin resistance in sheep.

Thymus Vulgaris Oil Nanoemulsion: Synthesis, Characterization, Antimicrobial and Anticancer Activities.

Essential oil nanoemulsions have received much attention due to their biological activities. Thus, a thyme essential oil nanoemulsion (Th-nanoemulsion) was prepared using a safe and eco-friendly method. DLS and TEM were used to characterize the prepared Th-nanoemulsion. Our findings showed that the nanoemulsion was spherical and ranged in size from 20 to 55.2 nm. The micro-broth dilution experiment was used to evaluate the in vitro antibacterial activity of a Th-emulsion and the Th-nanoemulsion. The MIC50 values of the thymol nanoemulsion were 62.5 mg/mL against Escherichia coli and Klebsiella oxytoca, 250 mg/mL against Bacillus cereus, and 125 mg/mL against Staphylococcus aureus. Meanwhile, it emerged that the MIC50 values of thymol against four strains were not detected. Moreover, the Th-nanoemulsion exhibited promising antifungal activity toward A. brasiliensis and A. fumigatus, where inhibition zones and MIC50 were 20.5 ± 1.32 and 26.4 ± 1.34 mm, and 12.5 and 6.25 mg/mL, respectively. On the other hand, the Th-nanoemulsion displayed weak antifungal activity toward C. albicans where the inhibition zone was 12.0 ± 0.90 and MIC was 50 mg/mL. Also, the Th-emulsion exhibited antifungal activity, but lower than that of the Th-nanoemulsion, toward all the tested fungal strains, where MIC was in the range of 12.5-50 mg/mL. The in vitro anticancer effects of Taxol, Th-emulsion, and Th-nanoemulsion were evaluated using the standard MTT method against breast cancer (MCF-7) and hepatocellular carcinoma (HepG2). Additionally, the concentration of VEGFR-2 was measured, and the activities of caspase-8 (casp-8) and caspase-9 (casp-9) were evaluated. The cytotoxic effect was the most potent against the MCF-7 breast cancer cell line after the Th-nanoemulsion treatment (20.1 ± 0.85 µg/mL), and was 125.1 ± 5.29 µg/mL after the Th-emulsion treatment. The lowest half-maximal inhibitory concentration (IC50) value, 20.1 ± 0.85 µg/mL, was achieved when the MCF-7 cell line was treated with the Th-nanoemulsion. In addition, Th-nanoemulsion treatments on MCF-7 cells led to the highest elevations in casp-8 and casp-9 activities (0.66 ± 0.042 ng/mL and 17.8 ± 0.39 pg/mL, respectively) compared to those with Th-emulsion treatments. In comparison to that with the Th-emulsion (0.982 0.017 ng/mL), the VEGFR-2 concentration was lower with the Th-nanoemulsion treatment (0.672 ± 0.019ng/mL). In conclusion, the Th-nanoemulsion was successfully prepared and appeared in nanoform with a spherical shape according to DLS and TEM, and also exhibited antibacterial, antifungal, as well as anticancer activities.

GSK-3 inhibitor elraglusib (9-ING-41) to enhance tumor-infiltrating immune cell activation in tumor biopsies and synergize with anti-PD-L1 in a murine model of colorectal cancer.

e15138 Background: Glycogen synthase kinase 3 (GSK-3) is a serine/threonine kinase with key roles in myriad biological processes such as tumor progression, and inhibition of GSK-3 using a novel small-molecule elraglusib has shown promising preclinical antitumor activity in multiple tumor types. Methods: We characterize the effects of elraglusib in vitro on tumor and immune cells including cell killing and cytokine profiling , in vivo in combination with checkpoint inhibitors in a syngeneic murine colon carcinoma BALB/c model using MSS cell line CT-26, and in human tumor biopsies and plasma samples from patients with refractory solid tumors of multiple tissue origins enrolled in a Phase 1 clinical trial investigating elraglusib ( NCT03678883 ).We used human plasma samples from patients treated with elraglusib, paired pre- and post-treatment tumor biopsies and performed digital spatial proteomics. Results: Elraglusib promoted immune cell-mediated tumor cell killing, enhanced tumor cell pyroptosis, decreased tumor cell NF-κB-regulated survival protein expression, and increased immune cell effector molecule secretion. Synergy was observed between elraglusib and anti-PD-L1 in an immunocompetent murine model of colorectal cancer. Murine responders had more tumor-infiltrating T-cells, fewer tumor-infiltrating Tregs, lower tumorigenic circulating cytokine concentrations, and higher immunostimulatory circulating cytokine concentrations. Murine responders had lower serum concentrations of BAFF, CCL7, CCL12, VEGF, VEGFR2, and CCL21, and higher serum concentrations of CCL4, TWEAK, GM-CSF, CCL22, and IL-12p70 as compared to non-responders. We utilized human plasma samples from patients treated with elraglusib and correlated cytokine profiles with survival. Elevated baseline plasma levels of proteins such as IL-1 β and reduced levels of proteins such as VEGF correlated with improved PFS and OS. PFS was also found to be positively correlated with elevated plasma levels of immunostimulatory analytes such as Granzyme B, IFN-γ, and IL-2 at 24 hours post-treatment with elraglusib. Several of these secreted proteins correlated with results from the in vivo study where expression of proteins such as IL-1 β, CCL22, CCL4, and TWEAK was positively correlated with improved response to therapy while expression of proteins such as BAFF and VEGF negatively correlated with response to therapy. Using paired tumor biopsies, we found that CD45+ tumor-infiltrating immune cells had lower expression of inhibitory immune checkpoints and higher expression of T-cell activation markers in post-elraglusib patient biopsies. Conclusions: These results introduce several immunomodulatory mechanisms of GSK-3 inhibition using elraglusib, providing a rationale for the clinical evaluation of elraglusib in combination with immunotherapy.

Effect of subacute poisoning with lambdacyhalothrin on vascular endothelial growth factor 2 receptor in mice kidneys

BackgroundPyrethroids are used for insect control. They act on voltage-gated sodium channels in neurons. Lambdacyhalothrin (LCH) is a type II pyrethroid producing choreoatetosis and salivation in rodents. Vascular endothelial growth factor (VEGF) expression in the kidney is high in the glomerular podocytes and kidney tubules. VEGF receptor 2 (VEFGR2) is the main mediator in angiogenesis and it regulates blood vessel permeability. Lack of VEGF in podocytes impairs filtration. The nuclear factor κB (NFκB) is widely known as an important mediator of inflammation.The aim of the study was to check if subacute oral intoxication with 0.1LD50 of LCH affects kidney size, function and VEGFR2 and NFκB in mice kidneys.MethodsA total of 32 Albino Swiss mice was used: females controls, males controls, females receiving 2 mg/kg LCH, males receiving 2 mg/kg LCH orally for 7 days. On day 8 animals were sacrificed, blood and kidneys were obtained. Kidney mass was determined, creatinine concentration was measured in blood sera, VEGFR2 and NFκB in kidney homogenate supernatant with ELISA kit.ResultsThere was no statistically significant differences in kidney mass, creatinine concentration in blood sera nor NFκB but mean VEGFR2 concentration in the kidneys of females exposed to LCH was 128.01 ng/ml and showed statistically significant difference in comparison with control females. There was no statistically significant difference between VEGFR2 concentration in the kidneys of males exposed to LCH and control males.ConclusionThe VEGFR2 increases in the course of LCH intoxication in females probably due to the protective effect of oestrogens.

Circulating vascular endothelial growth factor receptor 2 levels and their association with lipid abnormalities in patients on hemodialysis.

The aim of the present study was to examine the association between the levels of circulating vascular endothelial growth factor receptor (VEGFR)2 levels, serum lipid composition and plasma receptor for advanced glycation end-products (RAGE) expression in patients undergoing hemodialysis (HD). A total of 50 patients on HD (27 men and 23 women; median age, 66 years; age range 28-88 years; HD mean time, 29.0, 3.9-157.0 months) were enrolled. Age-matched healthy subjects (n=26) were used as the control group. Plasma VEGFR2 and RAGE levels were determined using ELISA. Dyslipidemia (D) in patients on HD was diagnosed according to the Kidney Disease Outcomes Quality Initiative Clinical Practice Guidelines for Managing Dyslipidemias in Chronic Kidney Disease. Circulating VEGFR2, RAGE and serum lipids were compared between dyslipidemic and non-dyslipidemic patients on HD and controls. In patients on HD, the plasma VEGFR2 levels were lower compared with those in the healthy population. D was associated with high plasma VEGFR2 levels. The triglyceride/HDL-cholesterol ratio was strongly associated with plasma VEGFR2 levels. The plasma VEGFR2 concentration was associated with circulating RAGE levels. Therefore, circulating VEGFR2 levels may be partly associated with lipid abnormalities and plasma RAGE levels in patients receiving HD.

Changes in the Expression Profile of VEGF-A, VEGF-B, VEGFR-1, VEGFR-2 in Different Grades of Endometrial Cancer.

BackgroundVEGF-A, VEGF-B, VEGFR-1 and VEGFR-2 are important proteins involved in the induction and development of a new blood vessel network through which the tumor is properly nourished and oxygenated.ObjectivesThe aim of the study was to evaluate changes in VEGF-A, VEGF-B, VEGFR-1 and VEGFR-2 expression in endometrial cancer depending on its grade and to determine the VEGFR-1 to VEGFR-2 concentration ratio.MethodsThe study group consisted of 45 patients diagnosed with endometrial cancer (G1, 17; G2, 15; G3, 13). The control group included 15 patients. VEGF-A, VEGF-B, VEGF-R1, VEGFR-2 expression was assessed using the immunohistochemical method. Statistical analysis was carried out using the Statistica 12 PL program (StatSoft, Cracow, Poland). It included the one-way ANOVA and Tukey's post-hoc test (p<0.05).ResultsStatistically significant differences in the level of VEGF-A, VEGF-B, VEGF-R1, VEGFR-2 were observed between the majority of analyzed groups (except for VEGF-B; G3 vs. G1, p=0.997700). The expression pattern of VEGF-A, VEGF-R1, VEGFR-2 was as follows: G3>G2>G1>C; VEGF-B: G2> G3> G1>C. A lower concentration of VEGFR-1 than VEGFR-2 was found regardless of the cancer grade.ConclusionVEGF-A, VEGF-B, VEGF-R1, VEGFR-2 are key proteins involved in tumor angiogenesis. The analysis of the entire panel of proteins participating in a given process is an important element of modern diagnostics. The concentration ratio of VEGFR-1 to VEGFR-2 appears to be a determining factor in the patients' survival prognosis.

Multiplexing Angiogenic Receptor Quantification via Quantum Dots.

Clinical and biomedical research seeks single-cell quantification to better understand their roles in a complex, multicell environment. Recently, quantification of vascular endothelial growth factor receptors (VEGFRs) provided important insights into endothelial cell characteristics and response in tumor microenvironments. However, existing technologies for quantifying plasma membrane receptor tyrosine kinases (RTKs) lack multiplexing capabilities, limiting detailed characterization. Here, we use the unique spectral properties of quantum dots (Qdots) to optimize and dually quantify VEGFR1 and VEGFR2 on human umbilical vein endothelial cells (HUVECs). To enable this quantification, we reduce nonspecific binding between Qdot-conjugated antibodies and cells via buffer optimization. Second, we identify optimal labeling conditions by examining Qdot-conjugated antibody binding to five receptors: VEGFRs (VEGFR1 and VEGFR2), their coreceptor neuropilin1 (NRP1), and platelet-derived growth factor receptor (PDGFRα and PDGFRβ). We establish that 800-20 000 is the dynamic range where accurate Qdot-enabled quantification can be achieved. Through these optimizations, we demonstrate measurement of 1 100 VEGFR1 and 6 900 VEGFR2 per HUVEC. We induce ∼90% upregulation of VEGFR1 and ∼30% downregulation of VEGFR2 concentration via 24 h VEGF-A165 treatment. We observe no change in VEGFR1 or VEGFR2 concentration with 24 h VEGF-B167 treatment. We further apply Qdots to analyze HUVEC heterogeneity and observe that 24 h VEGF-A165 treatment induces a ∼15% decrease in VEGFR2 heterogeneity, but little to no change in VEGFR1 heterogeneity. We observe that VEGF-B167 induces little to no change in either VEGFR1 or VEGFR2 heterogeneity. Overall, we demonstrate experimental and analytical strategies for quantifying two or more RTKs at single-level using Qdots, which will help provide new insights into biological systems.

Vitreous Fibronectin and Fibrinogen Expression Increased in Eyes With Proliferative Diabetic Retinopathy After Intravitreal Anti-VEGF Therapy.

To evaluate vitreous humor (VH) protein expression profiles in patients with proliferative diabetic retinopathy (PDR), with and without intravitreal injection (IVI) of anti-vascular endothelial growth factor (anti-VEGF) before vitrectomy. We enrolled consecutive PDR patients who needed pars plana vitrectomy (PPV) with or without IVI or pan-retinal photocoagulation (PRP). Visual acuity, duration, and treatment of diabetes mellitus, ocular treatment history, and fundus examinations were recorded. VH samples were collected without artificial humor infusion. Label-free quantitative proteomics analysis was performed to determine the protein expression profiles of VH samples. Enzyme-linked immunosorbent assays were performed to validate the proteomics results. PDR patients who underwent IVI at a mean of 5.8 days (range, 3-8 days) before PPV (IVI group, n = 12) were younger than PDR patients with a history of PRP (PRP group, n = 29) and untreated PDR patients (control group, n = 21). The duration of diabetes mellitus was similar in the three groups. Label-free quantitative proteomics analysis showed that the signal intensities for fibronectin, fibrinogen α chain, fibrinogen β chain, fibrinogen γ chain, VEGF receptor 1 (VEGFR1), and VEGFR2 were significantly greater in the IVI group than in the other two groups. Enzyme-linked immunosorbent assays validated the results for fibronectin and fibrinogens, but found no significant differences in VEGF or VEGFR2 concentrations. VEGFR1 expression was significantly greater in the IVI and PRP groups than in the control group. VH fibronectin and fibrinogen concentrations were highest in the IVI patients, which may promote fibrin-fibronectin complexation and fibrosis in eyes with PDR.

Identification of a variant in KDR associated with serum VEGFR2 and pharmacodynamics of Pazopanib.

VEGF receptor (VEGFR) kinases are important drug targets in oncology that affect function of systemic endothelial cells. To discover genetic markers that affect VEGFR inhibitor pharmacodynamics, we performed a genome-wide association study of serum soluble vascular VEGFR2 concentrations [sVEGFR2], a pharmacodynamic biomarker for VEGFR2 inhibitors. We conducted a genome-wide association study (GWAS) of [sVEGFR2] in 736 healthy Old Order Amish volunteers. Gene variants identified from the GWAS were genotyped serially in a cohort of 128 patients with advanced solid tumor with baseline [sVEGFR2] measurements, and in 121 patients with renal carcinoma with [sVEGFR2] measured before and during pazopanib therapy. rs34231037 (C482R) in KDR, the gene encoding sVEGFR2 was found to be highly associated with [sVEGFR2], explaining 23% of the variance (P = 2.7 × 10(-37)). Association of rs34231037 with [sVEGFR2] was replicated in 128 patients with cancer with comparable effect size (P = 0.025). Furthermore, rs34231037 was a significant predictor of changes in [sVEGFR2] in response to pazopanib (P = 0.01). Our findings suggest that genome-wide analysis of phenotypes in healthy populations can expedite identification of candidate pharmacogenetic markers. Genotyping for germline variants in KDR may have clinical utility in identifying patients with cancer with unusual sensitivity to effects of VEGFR2 kinase inhibitors.

Prognostic value of serum vascular endothelial growth factor receptor 2 response in patients with hepatocellular carcinoma undergoing transarterial chemoembolization

We aimed to elucidate whether serum VEGFR2 concentration before and after transarterial chemoembolization (TACE) can predict survival in patients with unresectable hepatocellular carcinoma (HCC). Serum VEGFR2 concentrations were serially measured in 169 patients with advanced HCC before and after TACE. We defined a decrease in the serum VEGFR2 level>10% from the pretreatment level as response. Serum VEGFR2 concentrations decreased in 44 (26.0%) patients at week 4. Patients who had a VEGFR2 response at week 4 had a longer median survival than those who did not have a VEGFR2 decrease (19.0 vs. 9.8 months, p<0.001). Clinical variables associated with OS in addition to VEGFR2 response also included extrahepatic metastases (p=0.005) and vascular invasion (p=0.035). VEGFR2 decrease after TACE (p=0.012) and presence of extrahepatic metastases (p=0.02) were independently associated with OS by multivariate analysis. A serum VEGFR2 concentration decrease at 4 weeks after TACE may predict favorable overall survival in patients with advanced HCC.

Perinatal systemic inflammatory responses of growth-restricted preterm newborns

To compare the early post-natal pattern of systemic inflammation in growth-restricted infants born before the 28th week of gestation to that of appropriately grown peers. We measured the concentrations of 25 inflammation-related proteins in blood spots collected from 939 newborns during the first 2 post-natal weeks. We calculated the odds ratios (99% confidence intervals) that concentrations would be in the highest quartile. Severely growth-restricted infants (birth weight Z-score <-2) were not at increased risk of systemic inflammation shortly after birth. On post-natal day 14, however, they were significantly more likely than their peers to have a CRP, IL-1β, IL-6, TNF-α, IL-8, MCP-4, ICAM-1, ICAM-3, E-SEL, MMP-9, VEGF-R2 and/or IGFBP-1 concentration in the highest quartile. These increased risks could not be attributed to delivery indication, bacteremia or duration of ventilation. Growth-restricted preterm newborns appear to be at increased risk of elevated concentrations of inflammation-associated proteins by post-natal day 14.

Bridging sunitinib exposure to time-to-tumor progression in hepatocellular carcinoma patients with mathematical modeling of an angiogenic biomarker.

e14690 Background: Hepatocellular carcinoma (HCC) is the most common primary liver malignancy with 250,000 new annual cases in the US. Sunitinib (SU), an oral tyrosine kinase inhibitor, inhibits tumor cell proliferation, selectively binds to the angiogenesis biomarker (VEGFR2), and is metabolized to an equipotent metabolite (SU12662). The objective of this study is to utilize mathematical modeling to bridge drug exposure and VEGFR2 dynamics to tumor growth inhibition (TGI) and time-to-tumor progression (TTP). Methods: Plasma concentrations of SU, SU12662, and VEGFR2, and tumor growth and TTP measurements were obtained from a phase-II study in 16 patients with unresectable HCC. SU was administered at 37.5 mg daily 7-days prior to chemoembolization, then on days 15-35. A MAP Bayesian approach was utilized to model SU and SU12662 pharmacokinetics (PK), both captured with a two-compartment model including linear clearances. Inhibition of VEGFR2 production was mediated by predicted active unbound concentrations (ACub) of SU and SU12662. VEGFR2 concentrations were the driver for TGI. The TTP probability was modeled with exponential hazard function dependent on a time varying covariate -the difference in VEGFR2 concentration from its baseline (ΔVEGFR2). Results: Drug and metabolite clearances (CLd, CLm) were estimated at 30.3 (19, %RSE) and 19.7L/h (14). Their volumes of distribution (Vd, Vm) were 1,780 (39) and 1840L (25). SU exposure was within target range for VEGFR2 inhibition. VEGFR2 half-life in plasma was calculated at 4h. The slope (α) for ACub effect on VEGFR2 production was 0.77(µg/mL)-1 (14). The ΔVEGFR2 effect on TGI was assumed maximal, whereas its potency (ΔIC50) was estimated at 1.83x10-2µg/mL (41). The between-subjects variabilities were 37.4, 51, 44.7, 64.8, 21, and 36% for CLd, CLm, Vd, Vm, α, and ΔIC50. The median observed tumor size baseline was 91 mm3. The simulated mean TTP was 7 months. Conclusions: The time-course of SU, SU12662, and VEGFR2 were captured well with final PK/pharmacodynamic models. VEGFR2 profiles successfully linked drug exposure to TGI and TTP. This model may serve as a general platform for the dynamics of anti-angiogenic drugs.

Key predictive factors of axitinib (AG-013736)-induced proteinuria and efficacy: A phase II study in Japanese patients with cytokine-refractory metastatic renal cell Carcinoma

BackgroundAxitinib (AG-013736) is an oral, selective and potent inhibitor of vascular endothelial growth factor receptors (VEGFR)-1, 2 and 3. This phase II study investigated axitinib efficacy, safety and biomarkers in Japanese patients with cytokine-refractory metastatic renal cell carcinoma (mRCC). Patients and methodsIn an open-label, multicentre study, 64 patients received an axitinib starting dose of 5mg twice daily. ResultsObjective response rate (ORR) was 50.0% and median progression-free survival (PFS) was 11.0months per independent review committee. Common treatment-related adverse events were hypertension (84%; 70% grade ⩾3), hand–foot syndrome (75%; 22% grade ⩾3) and diarrhoea (64%; 5% grade ⩾3). Eighteen patients (28%) developed proteinuria ⩾2g/24h and required dose reduction or treatment interruption/discontinuation. Proteinuria was a major cause for treatment discontinuation. Baseline urine protein levels were associated with development of proteinuria ⩾2g/24h (hazard ratio [HR]=5.457, P=0.0035 in patients with baseline proteinuria ⩾1+ versus <1+). Baseline urine protein levels correlated more strongly with axitinib-related proteinuria than other baseline renal function test values or blood pressure. Patients with greater decreases in soluble VEGFR-2 concentrations had significantly higher ORR and longer PFS than those with smaller decreases (ORR: 64.5% versus 37.5%, P=0.045; median PFS: 12.9months versus 9.2months, HR=0.42, P=0.01). ConclusionsAxitinib showed significant antitumour activity and was well tolerated in Japanese mRCC patients. Baseline proteinuria and soluble VEGFR-2 levels may be key indicators of axitinib-induced proteinuria and efficacy, respectively.

Combined VEGF-A and VEGFR-2 concentrations in plasma: Diagnostic and prognostic implications in patients with advanced NSCLC

Introduction The vascular endothelial growth factor (VEGF) family of ligands and receptors (VEGFR) play an important role in tumor angiogenesis. Increased expression of angiogenic factors in tumors or in blood is associated with poor prognosis. The aim of this study was to investigate the role of VEGF-A and soluble VEGFR-2 (sVEGFR-2) as biomarkers in advanced non-small-cell lung cancer (NSCLC). Methods We studied 432 patients with advanced NSCLC (stages IIIB–IV) treated with cisplatin and docetaxel and 89 healthy age-matched controls. Blood samples were collected before chemotherapy, and VEGF-A and sVEGFR-2 levels were determined by ELISA. Results VEGF-A and sVEGFR-2 levels were higher in NSCLC patients than in the controls, but VEGF-A behaves as a better diagnostic biomarker. There were no significant associations between VEGF-A and sVEGFR-2 concentrations and clinical characteristics, such as ECOG-PS, gender, stage, histology, metastases, and treatment response. A patient subgroup characterized by a combination of high VEGF-A and low sVEGFR-2 levels exhibited the worst patient prognoses in terms of TTP and OS. Conclusions VEGF-A and sVEGFR-2 levels were significantly higher in patients than in the controls. A combination of VEGF-A and sVEGFR-2 can be used as an independent prognostic biomarker in advanced NSCLC.

Expression of vascular endothelial growth factor receptor-1/-2 and nitric oxide in unruptured intracranial aneurysms

The biological mechanisms associated with the development and rupture of intracranial aneurysms are not fully understood. To clarify the role of VEGF and the related receptors in the pathophysiology of aneurysm, immunostaining for VEGF, VEGFR1 and VEGFR2 was performed on specimens from six unruptured aneurysms and on two specimens of normal arteries wall as a control. The results were correlated with NO concentration of CSF collected during surgery from 8 patients affected by unruptured aneurysms and in 11 control patients. The immunohistochemical data showed a different pattern of VEGF/VEGFR1/VEGFR2 in aneurysms when compared with control. The results of this preliminary study suggest an imbalance of VEGF, VEGFR1 and VEGFR2, and the interaction of VEGF and NO in the pathophysiology of unruptured aneurysms. Our data support the hypothesis of aneurysm formation associated with a loss of expression of VEGFR1, moderate expression of VEGFR2 and high concentration of nitrate.

The Different Concentrations of Transforming Growth Factor-Beta1 (TGF-Beta1), Matrix Metalloproteinase-9 (MMP-9) and Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) in Normoalbuminuria Normotension, Normoalbuminuria Hypertension

BACKGROUND: Vascular remodeling was an adaptive process of the vascular wall that occured in response to long-term changes in hemodynamic conditions that contribute to the changes of the vascular structure and the pathophysiology of vascular disease. On the other hand, Endothelial Progenitor Cells (EPC) derived from bone marrow had the capacity to migrate to the peripheral circulation and to differentiate into mature endothelial cells. Therefore, EPC could contribute in the endothelial repairing after endothelial injury.METHODS: This study was a cross sectional design. Analysis was done among 30 subjects with normoalbuminuria normotension, 55 subjects with normoalbuminuria hypertension and 30 subjects with with microalbuminuria hypertension. TGF-β1, MMP-9 and VEGFR-2 testing were performed by ELISA method. All statistical calculations were performed using the SPSS 11.5 statistical software package. We used the Independent sample T test, Mann-Whitney, One Way Annova and Kruskal Wallis to establish the difference among various biochemical measures.RESULTS: TGF-β1 concentration was increased from normoalbuminuria normotension to normoalbuminuria hypertension and to microalbuminuria hypertension (27.63178±12.97246 vs. 38.61193±17.09546 vs. 38.73939±12.63911 ng/mL). TGF-β1 concentration was higher significantly in normotension as compared to hypertension (27.63178±12.97246 vs. 38.65692±15.58950, p&lt;0.001) and to microalbuminuria hypertension (38.73939±12.63911, p&lt;0.001). MMP-9 concentration was increased in normotension to normoalbuminuria hypertension but was decreased in microalbuminuria hypertension (438.1967±156.4268 vs. 564.5873±291.2876 vs. 418.6900±188.3801 ng/mL). MMP-9 concentration was higher significantly in normoalbuminuria hypertension as compared to microalbuminuria hypertension (p=0.028). VEGFR-2 concentration was decreased from normotension to normoalbuminuria hypertension to microalbuminuria hypertension (9.90552±1.85185 vs. 9.39561±1.75413 vs. 9.00506±1.47173 ng/mL). VEGFR-2 concentration was higher significantly in normotension as compared to microalbuminuria hypertension (p=0.042). CONCLUSIONS: The increasing concentration level of TGF-β1 and decreasing concentration level of MMP-9 in microalbuminuria hypertension showed that the remodeling process was getting increased. The decreasing concentration level of VEGFR-2 in microalbuminuria hypertension showed that the repairing process was getting decreased.KEYWORDS: vascular remodelling, vascular repairing, TGF-β1, MMP-9, VEGFR-2

Continuous daily dosing (CDD) of sunitinib (SU) in pts with advanced GIST: Updated efficacy, safety, PK and pharmacodynamic analysis

10554 Background: SU is an oral multitargeted tyrosine kinase inhibitor of KIT, PDGFRs, VEGFRs, FLT3, CSF-1R and RET, approved multinationally for the treatment of advanced imatinib (IM)-resistant/intolerant GIST on an intermittent dosing schedule comprising 4 wk on 50 mg/d followed by 2 wk off treatment. The safety and efficacy of SU 37.5 mg CDD in pts with GIST after IM failure were evaluated in this phase II study. Methods: In this open-label, multicenter trial, pts were randomized either to morning (AM) or evening SU dosing. The primary endpoint was clinical benefit rate (CBR; % of pts with RECIST-defined CR, PR or SD ≥24 wk). Secondary endpoints included PFS, OS, ORR, safety/tolerability, PK parameters and plasma concentrations of potential biomarkers. Results: 60/61 randomized pts (30/arm) received CDD of SU. As of Dec. 2007, pts had started a median of 11 28-d treatment cycles (range 1–24). 24 pts had completed 1 y of study treatment, and 37 had discontinued. To date, the overall CBR is 55%, including 7 pts (12%) with PRs. Median PFS overall is 32 wk (95% CI 25–48). With 60% of pts still alive, median OS is estimated to be 88 wk (95% CI 68-NA). The most common treatment-emergent (all- causality) non-hematologic Aes of any grade were diarrhea (45%), abdominal pain (42%) and asthenia (38%). Grade 3/4 hematologic laboratory abnormalities included reduced levels of neutrophils (12%), hemoglobin (12%) and platelets (3%). Dose reduction to 25 mg due to Aes occurred in 14 pts (23%). Sunitinib CDD achieved constant drug exposure with no unexpected accumulation. 23 pts on AM dosing had plasma samples taken at ≥2 timepoints during treatment. Analysis of VEGF, soluble (s)VEGFR-2, sVEGFR-3 and sKIT concentrations in these samples supported a persistent pharmacodynamic effect of SU with CDD, without the concentration rebound observed during off-treatment periods with intermittent dosing. Preliminary analyses suggested a correlation between OS and decreases in plasma sKIT after the first 3 cycles, and particularly after cycle 5 (n=17; P=0.007). Conclusions: CDD of SU appears to be a safe and potentially effective dosing strategy for pts with GIST after IM failure. CDD is associated with constant drug exposure and a persistent pharmacodynamic effect. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Pfizer GlaxoSmithKline, Infinity, MedImmune, Novartis, Pfizer, PharmaMar, Roche, sanofi-aventis Pfizer GlaxoSmithKline, Novartis, Pfizer, PharmaMar, Roche, SigmaTau Infinity, Janssen-Cilag, Novartis, Pfizer, SigmaTau Infinity, Novartis, Pfizer Novartis, PharmaMar

IIIB.1 Adjuvant chemotherapy in elderly patients: an analysis of National Cancer Institute of Canada Clinical Trials Group and Intergroup JBR.10

Axitinib (AG-013736) is an oral, selective and potent inhibitor of vascular endothelial growth factor receptors (VEGFR)-1, 2 and 3. This phase II study investigated axitinib efficacy, safety and biomarkers in Japanese patients with cytokine-refractory metastatic renal cell carcinoma (mRCC).In an open-label, multicentre study, 64 patients received an axitinib starting dose of 5 mg twice daily.Objective response rate (ORR) was 50.0% and median progression-free survival (PFS) was 11.0 months per independent review committee. Common treatment-related adverse events were hypertension (84%; 70% grade ⩾3), hand–foot syndrome (75%; 22% grade ⩾3) and diarrhoea (64%; 5% grade ⩾3). Eighteen patients (28%) developed proteinuria ⩾2 g/24 h and required dose reduction or treatment interruption/discontinuation. Proteinuria was a major cause for treatment discontinuation. Baseline urine protein levels were associated with development of proteinuria ⩾2 g/24 h (hazard ratio [HR] = 5.457, P = 0.0035 in patients with baseline proteinuria ⩾1+ versus <1+). Baseline urine protein levels correlated more strongly with axitinib-related proteinuria than other baseline renal function test values or blood pressure. Patients with greater decreases in soluble VEGFR-2 concentrations had significantly higher ORR and longer PFS than those with smaller decreases (ORR: 64.5% versus 37.5%, P = 0.045; median PFS: 12.9 months versus 9.2 months, HR = 0.42, P = 0.01).Axitinib showed significant antitumour activity and was well tolerated in Japanese mRCC patients. Baseline proteinuria and soluble VEGFR-2 levels may be key indicators of axitinib-induced proteinuria and efficacy, respectively.

IIIA.3 Targeted therapy in elderly cancer patients. Renal cell carcinoma

Axitinib (AG-013736) is an oral, selective and potent inhibitor of vascular endothelial growth factor receptors (VEGFR)-1, 2 and 3. This phase II study investigated axitinib efficacy, safety and biomarkers in Japanese patients with cytokine-refractory metastatic renal cell carcinoma (mRCC).In an open-label, multicentre study, 64 patients received an axitinib starting dose of 5 mg twice daily.Objective response rate (ORR) was 50.0% and median progression-free survival (PFS) was 11.0 months per independent review committee. Common treatment-related adverse events were hypertension (84%; 70% grade ⩾3), hand–foot syndrome (75%; 22% grade ⩾3) and diarrhoea (64%; 5% grade ⩾3). Eighteen patients (28%) developed proteinuria ⩾2 g/24 h and required dose reduction or treatment interruption/discontinuation. Proteinuria was a major cause for treatment discontinuation. Baseline urine protein levels were associated with development of proteinuria ⩾2 g/24 h (hazard ratio [HR] = 5.457, P = 0.0035 in patients with baseline proteinuria ⩾1+ versus <1+). Baseline urine protein levels correlated more strongly with axitinib-related proteinuria than other baseline renal function test values or blood pressure. Patients with greater decreases in soluble VEGFR-2 concentrations had significantly higher ORR and longer PFS than those with smaller decreases (ORR: 64.5% versus 37.5%, P = 0.045; median PFS: 12.9 months versus 9.2 months, HR = 0.42, P = 0.01).Axitinib showed significant antitumour activity and was well tolerated in Japanese mRCC patients. Baseline proteinuria and soluble VEGFR-2 levels may be key indicators of axitinib-induced proteinuria and efficacy, respectively.