Clinical phase I study of elpamotide,a peptide vaccine for vascular endothelial growth factor receptor 2, in patients with advanced solid tumors

Targeting of tumor angiogenesis with vaccines is a potentially valuable approach to cancer treatment. Elpamotide is an immunogenic peptide derived from vascular endothelial growth factor receptor 2, which is expressed at a high level in vascular endothelial cells. We have now carried out a phase I study to evaluate safety, the maximum tolerated dose, and potential pharmacodynamic biomarkers for this vaccine. Ten HLA‐A*24:02‐positive patients with advanced refractory solid tumors received elpamotide s.c. at dose levels of 0.5, 1.0, or 2.0 mg once a week on a 28‐day cycle. Five patients experienced an injection site reaction of grade 1 and 2, which was the most frequent adverse event. In the 1.0 mg cohort, one patient experienced proteinuria of grade 1 and another patient developed both hypertension and proteinuria of grade 1. No adverse events of grade 3 or higher were observed, and the maximum tolerated dose was therefore not achieved. The serum concentration of soluble vascular endothelial growth factor receptor 2 decreased significantly after elpamotide vaccination. Microarray analysis of gene expression in PBMCs indicated that several pathways related to T cell function and angiogenesis were affected by elpamotide vaccination, supporting the notion that this peptide induces an immune response that targets angiogenesis in the clinical setting. In conclusion, elpamotide is well tolerated and our biomarker analysis indicates that this anti‐angiogenic vaccine is biologically active. Clinical trial registration no. UMIN000008336.     

Phase I clinical trial of cell division associated 1 (CDCA1) peptide vaccination for castration resistant prostate cancer

Cell division associated 1 (CDCA1) was screened as an oncogene that is overexpressed on several cancers, including prostate cancer. A highly immunogenic HLA‐A*2402‐restricted epitope peptide corresponding to part of the CDCA1 protein was also identified. A phase I clinical trial was conducted for patients with castration resistant prostate cancer (CRPC) using a CDCA1 peptide vaccination. Twelve patients having HLA‐A*2402 with CRPC after failure of docetaxel chemotherapy were enrolled. They received subcutaneous administration of the CDCA1 peptide as an emulsion with Montanide ISA51VG once a week in a dose‐escalation manner (doses of 1.0 or 3.0 mg/body, six patients received each dose). The primary endpoint was safety, and the secondary endpoints were the immunological and clinical responses. Vaccination with CDCA1 peptide was well tolerated without any serious adverse events. Peptide‐specific cytotoxic T lymphocyte (CTL) responses using ELISPOT assay and dextramer assay were observed in three patients receiving the 1.0 mg dose and five patients receiving the 3.0 mg dose. The median overall survival time was 11.0 months and specific CTL reacting to CDCA1 peptide were recognized in long‐surviving patients. CDCA1‐derived peptide vaccine treatment was tolerable and might effectively induce peptide‐specific CTLs for CRPC patients. This novel peptide vaccine therapy for CRPC appears promising. (ClinicalTrials.gov number, NCT01225471).     

EORTC study 26041-22041: Phase I/II study on concomitant and adjuvant temozolomide (TMZ) and radiotherapy (RT) with PTK787/ZK222584 (PTK/ZK) in newly diagnosed glioblastoma

BackgroundGlioblastoma is a highly vascularised tumour with a high expression of both vascular endothelial growth factor (VEGF) and VEGFR. PTK787/ZK222584 (PTK/ZK, vatalanib), a multiple VEGF receptor inhibitor, blocks the intracellular tyrosine kinase activity of all known VEGF receptors and is therefore suitable for long-term therapy of pathologic tumour neovascularisation.Patients and methodsThe study was designed as an open-label, phase I/II study. A classic 3 + 3 design was selected. PTK/ZK was added to standard concomitant and adjuvant treatment, beginning in the morning of day 1 of radiotherapy (RT), and given continuously until disease progression or toxicity. PTK/ZK doses started from 500 mg with subsequent escalations to 1000 and 1250 mg/d. Adjuvant or maintenance PTK after the end of radiochemotherapy was given at a previously established dose of 750 mg twice daily continuously with TMZ at the standard adjuvant dose.ResultsTwenty patients were enrolled. Dose-limiting toxicities at a once daily dose of 1250 mg were grade 3 diarrhoea (n = 1), grade 3 ALT increase (n = 2), and myelosuppression with grade 4 thrombocytopenia and neutropenia (n = 1). The recommended dose of PTK/ZK in combination with radiotherapy and temozolomide (TMZ) is 1000 mg once a day. This treatment is safe and well tolerated.ConclusionIn our phase I study once daily administration of up to 1000 mg of PTK/ZK in conjunction with concomitant temozolomide and radiotherapy was feasible and safe. Prolonged administration of this oral agent is manageable. The planned randomised phase II trial was discontinued right at its onset due to industry decision not to further develop this agent.     

Preclinical characterization of anlotinib,a highly potent and selective vascular endothelial growth factor receptor‐2 inhibitor

Abrogating tumor angiogenesis by inhibiting vascular endothelial growth factor receptor‐2 (VEGFR2) has been established as a therapeutic strategy for treating cancer. However, because of their low selectivity, most small molecule inhibitors of VEGFR2 tyrosine kinase show unexpected adverse effects and limited anticancer efficacy. In the present study, we detailed the pharmacological properties of anlotinib, a highly potent and selective VEGFR2 inhibitor, in preclinical models. Anlotinib occupied the ATP‐binding pocket of VEGFR2 tyrosine kinase and showed high selectivity and inhibitory potency (IC₅₀ <1 nmol/L) for VEGFR2 relative to other tyrosine kinases. Concordant with this activity, anlotinib inhibited VEGF‐induced signaling and cell proliferation in HUVEC with picomolar IC₅₀ values. However, micromolar concentrations of anlotinib were required to inhibit tumor cell proliferation directly in vitro. Anlotinib significantly inhibited HUVEC migration and tube formation; it also inhibited microvessel growth from explants of rat aorta in vitro and decreased vascular density in tumor tissue in vivo. Compared with the well‐known tyrosine kinase inhibitor sunitinib, once‐daily oral dose of anlotinib showed broader and stronger in vivo antitumor efficacy and, in some models, caused tumor regression in nude mice. Collectively, these results indicate that anlotinib is a well‐tolerated, orally active VEGFR2 inhibitor that targets angiogenesis in tumor growth, and support ongoing clinical evaluation of anlotinib for a variety of malignancies.     

Antitumor activities of synthetic and natural stilbenes through antiangiogenic action

We reported that the antitumor and antimetastatic actions of resveratrol might be due to the inhibition of tumor‐induced angiogenesis. To search for anticancer agents with stronger activity than resveratrol, we examined the antiangiogenic effects of 21 synthetic and/or natural stilbenes. Among these 21 stilbenes, 2,3‐, 3,4‐, and 4,4′‐dihydroxystilbene inhibited the pro‐matrix metalloproteinase (pro‐MMP)–9 production in colon 26 cells at 5–25 µM, vascular endothelial growth factor (VEGF)–induced human umbilical vein endothelial cell (HUVEC) migration at 10 and 25 µM, and VEGF‐induced angiogenesis at 5–50 µM. Resvertarol inhibited the pro‐MMP‐9 production and VEGF‐induced angiogenesis at 25 or 50 µM. Thus, the inhibition of pro‐MMP‐9 production in colon 26 cells and VEGF‐induced angiogenesis by three dihydroxystilbenes were greater than those of resveratrol. The three dihydroxystilbenes (8 mg/kg, intraperitoneal injection) inhibited the tumor‐induced neovascularization in colon 26–packed chamber‐bearing mice and the tumor growth in colon 26–bearing mice. Furthermore, the three dihydroxystilbenes inhibited VEGF‐induced VEGFR‐2 phosphorylation. On the other hand, the three dihydroxystilbenes had no effect on VEGFR‐1 and‐2 expression, and VEGF‐induced VEGFR‐1 phosphorylation in HUVECs. These findings suggest that the inhibition of tumor‐induced neovascularization by these three dihydroxystilbenes may be due to the inhibition of VEGF‐induced endothelial cell migration and VEGF‐induced angiogenesis through the inhibition of VEGF‐induced VEGFR‐2 phosphorylation in endothelial cells and pro‐MMP‐9 expression in colon 26 cells. (Cancer Sci 2008; 99: 2083–2096)     

Variable sensitivity of endothelial cells to epirubicin in xenografts of human nasopharyngeal carcinoma CNE-2 cells

Conventional anticancer drugs show non-specific vascular toxicity, and using anticancer drugs as angiogenesis inhibitors was suggested. However, our previous study suggested that vascular endothelial growth factor (VEGF) protected endothelial cells against chemotherapy drugs in vitro. To further test whether the vascular toxicity of anticancer drugs is active in vivo, epirubicin was i.p. injected into nude mice with s.c. xenografts of human nasopharyngeal carcinoma CNE-2 once (one-day schedule) or once a day from day 1 to day 7 (seven-day schedule). At 48 hours after the single injection or the 7th injection tumors were removed for detection of apoptosis of vascular endothelial cells vessels and the content of VEGF in tumor tissues. The results showed that epirubicin damaged tumor microvessels when the drug was given as a single dose, whereas epirubicin lost its vascular toxicity when the drug was given continuously for seven days, accompanied by higher levels of VEGF in tumor tissues. These results suggest the sensitivity of endothelial cells lining tumor vessels is variable during chemotherapy, and the protective effect of VEGF on endothelial cells might be related to the schedule of administration.     

Expression of p53, inducible nitric oxide synthase and vascular endothelial growth factor in gastric precancerous and cancerous lesions: correlation with clinical features

Background  

The growth and metastasis of tumors depend on the development of an adequate blood supply via angiogenesis. Recent studies indicate that the inducible nitric oxide synthase (iNOS), vascular endothelial growth factor (VEGF) and the tumor suppressor p53 are fundamental play-markers of the angiogenic process. Overexpression of iNOS and VEGF has been shown to induce angiogenesis in tumors. P53 suppresses angiogenesis by down-regulating VEGF and iNOS. The correlation of expression of p53, VEGF and iNOS and clinical features in gastric carcinogenesis, however, has not been well characterized.     

Heat shock protein 105 peptide vaccine could induce antitumor immune reactions in a phase I clinical trial

Heat shock protein 105 (HSP105) is overexpressed in many cancers, including colorectal cancer (CRC) and esophageal cancer (EC). We carried out a phase I clinical trial of HLA‐A24‐ and HLA‐A2‐restricted HSP105 peptide vaccines in patients with CRC or EC. In this additional study of the trial, we examined the immunological efficacy of the novel vaccine. Thirty patients with advanced CRC or EC underwent HSP105 peptide vaccination. Immunological responses were evaluated by ex vivo and in vitro γ‐interferon enzyme‐linked immunospot assays and their correlation with patients’ prognosis was analyzed. The HSP105 peptide vaccines induced peptide‐specific CTLs in 15 of 30 patients. Among HLA‐A24 patients (n = 15), 7 showed induction of CTLs only ex vivo, whereas among HLA‐A2 patients (n = 15), 4 showed the induction ex vivo and 6 in vitro. Heat shock protein 105‐specific CTL induction correlated with suppression of cancer progression and was revealed as a potential predictive biomarker for progression‐free survival (P = .008; hazard ratio = 3.03; 95% confidence interval, 1.34‐6.85) and overall survival (P = .025; hazard ratio = 2.72; 95% confidence interval, 1.13‐6.52). Production of cytokines by HSP105 peptide‐specific CTLs was observed at the injection sites (skin) and tumor tissues, suggesting that HSP105‐specific CTLs not only accumulated at vaccination sites but also infiltrated tumors. Furthermore, we established 2 HSP105 peptide‐specific CTL clones, which showed HSP105‐specific cytokine secretion and cytotoxicity. Our results suggest that the HSP105 peptide vaccine could induce immunological effects in cancer patients and improve their prognosis.     

Phase I study of cetuximab, erlotinib, and bevacizumab in patients with advanced solid tumors

Background  Complex interrelationships exist between the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) receptor pathways. EGFR activation elicits cell proliferation and increased VEGF expression. To maximally inhibit EGFR and then downstream VEGF activity, this phase I study was initiated to determine the maximum tolerated dose (MTD) of erlotinib with fixed-dose cetuximab, and then combine with bevacizumab in patients with advanced malignancies. Patients and methods  Patients with advanced malignancies likely to express EGFR were treated with a full dose of cetuximab intravenous weekly, combined with various doses of oral erlotinib daily (Part 1). Once the MTD was determined in Part 1, escalating doses of bevacizumab were administered intravenously biweekly (Part 2). Results  Forty patients were enrolled and received 155 courses over four dose levels. In Part 1, dose-limiting grade 3 rash occurred in two patients administered with erlotinib at 100 mg daily, and the MTD of erlotinib for this combination was 50 mg daily with standard-dose cetuximab (11 patients treated). Other adverse events included rash, diarrhea, fatigue, and hypomagnesemia. In Part 2, bevacizumab at 10 mg/kg intravenous every 2 weeks was safely added, with additional nondose-limiting headache, proteinuria, and hypertension. There was one partial response in a patient with renal cell carcinoma. Durable stable disease was observed in five patients for 6–11 months. Conclusions  The MTD for Part 1 was 50 mg daily of erlotinib combined with standard cetuximab. Bevacizumab at 10 mg/kg biweekly can be safely administered with the MTD for erlotinib and cetuximab combination. Presented in part at the 42nd Annual Meeting of American Society of Clinical Oncology, Atlanta, Georgia, June 2–6, 2006, and at the 18th EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics, Prague, Czech Republic, November 7–10, 2006. Chia-Chi Lin and Emiliano Calvo contributed equally to this study.     

表达VEGFR-2的减毒鼠伤寒沙门氏菌疫苗诱导特异性抗胶质瘤血管免疫应答

背景与目的:血管内皮生长因子(vascular endothelialgrowth factor,VEGF)及其主要受体血管内皮生长因子受体-2(vascular endothelialgrowth factorreceptor-2,VEGFR-2)在肿瘤新生血管和肿瘤基质形成过程中起着重要作用。本研究的目的是观察表达鼠VEGFR-2的重组减毒沙门氏疫苗菌诱导的抗血管特异性免疫应答及抗胶质瘤作用。方法:构建真核表达载体pcDNA3.1-VEGFR2,通过电转化法将pcDNA3.1-VEGFR2导入减毒鼠伤寒沙门氏菌SL7207中,经由胃管饲予C57BL/6J小鼠,对小鼠进行基因免疫。采用ELISA法检测免疫小鼠血清中特异性抗VEGFR2-IgG抗体,分离免疫小鼠的脾细胞,分析重组疫苗菌免疫后小鼠体内的特异性细胞毒性T细胞(cytotoxic T lym phocyte,CTL)应答。用携带pcDNA3.1-VEGFR2的重组沙门氏菌免疫治疗胶质瘤荷瘤小鼠,通过测量荷瘤小鼠肿瘤大小,检测肿瘤微血管密度及肿瘤细胞凋亡,评价重组疫苗菌的抗血管及肿瘤生长抑制作用。结果:重组疫苗菌免疫后小鼠产生了高水平的抗VEGFR2-IgG抗体,诱导小鼠脾淋巴细胞产生针对VEGFR2的特异性CTL活性。重组疫苗菌的免疫能够明显抑制胶质瘤的生长。NaH CO3对照组、载体对照组、重组疫苗菌组的平均微血管密度分别为26.5±5.8、27.2±4.5、8.8±1.9,平均凋亡细胞数分别为4.41.2、3.     

Phase I study of highly selective inhibitor of VEGFR tyrosine kinase,tivozanib, in Japanese patients with solid tumors

Tivozanib is a potent and selective inhibitor of vascular endothelial growth factor receptor (VEGFR) tyrosine kinases. A previous clinical trial in the EU and USA indicated that tivozanib at the maximum tolerated dose of 1.5 mg/day showed an antitumor activity in patients with renal cell carcinoma. This Japanese phase I study was designed to determine the recommended phase II dose of tivozanib for Japanese patients; secondary objectives included pharmacokinetic/pharmacodynamic profiles and preliminary efficacy. Daily treatment with tivozanib in a 3‐weeks‐on/1‐week‐off cycle was examined in nine Japanese patients with advanced solid tumors in the 3 + 3 design (Level 1, 1.0 mg; Level 2, 1.5 mg). No dose‐limiting toxicity was observed throughout the study, and the maximum tolerated dose was not reached. The most commonly observed drug‐related adverse events were diarrhea, dysphonia, rash, thyroid stimulating hormone increase, and with severity grade ≥3, hand‐foot skin reaction, hypertension, and proteinuria. Those adverse events were generally well‐manageable and mostly resolved within the tolerability evaluation period. Serum exposure to tivozanib resulted in t_1/2 of more than >60 h. Increase of plasma VEGF and decrease of plasma VEGFR‐1 and VEGFR‐2 were observed 1–3 weeks after tivozanib treatment. Although no complete or partial response was observed, long‐term stable disease continuing more than 170 days was observed in three renal cell carcinoma patients who had failed prior VEGFR inhibitors. In conclusion, 1.5 mg/day of tivozanib in a 3‐weeks‐on/1‐week‐off setting was tolerable in Japanese patients, and was recommended for further clinical trials in the Japanese population. Clinical trial Registration No: JapicCTI‐090854.     

Rationale for antiangiogenic cancer therapy with vaccination using epitope peptides derived from human vascular endothelial growth factor receptor 2

Angiogenesis is a critical mechanism for tumor progression. Multiple studies have suggested that tumor growth can be suppressed if tumor angiogenesis can be inhibited using various types of antiangiogenic agents. Recent studies in mouse systems have shown that tumor angiogenesis can also be inhibited if cellular immune response could be induced against vascular endothelial growth factor receptor 2 (VEGFR2), which is one of the key factors in tumor angiogenesis. In this study, we examined the possibility of developing this novel immunotherapy in clinical setting. We first identified the epitope peptides of VEGFR2 and showed that stimulation using these peptides induces CTLs with potent cytotoxicity in the HLA class I-restricted fashion against not only peptide-pulsed target cells but also endothelial cells endogenously expressing VEGFR2. In A2/Kb transgenic mice that express alpha1 and alpha2 domains of human HLA-A*0201, vaccination using these epitope peptides in vivo was associated with significant suppression of the tumor growth and prolongation of the animal survival without fatal adverse effects. In antiangiogenesis assay, tumor-induced angiogenesis was significantly suppressed with the vaccination using these epitope peptides. Furthermore, CTLs specific to the epitope peptides were successfully induced in cancer patients, and the specificities of the CTLs were confirmed using functional and HLA-tetramer analysis. These results in vitro and in vivo strongly suggest that the epitope peptides derived from VEGFR2 could be used as the agents for antiangiogenic immunotherapy against cancer in clinical settings.     

A phase I study of the combination of ro4929097 and cediranib in patients with advanced solid tumours (PJC-004/NCI 8503)

Background:

The Notch signalling pathway has been implicated in tumour initiation, progression, angiogenesis and development of resistance to vascular endothelial growth factor (VEGF) targeting, providing a rationale for the combination of RO4929097, a γ-secretase inhibitor, and cediranib, a VEGF receptor tyrosine kinase inhibitor.

Methods:

Patients received escalating doses of RO4929097 (on a 3 days-on and 4 days-off schedule) in combination with cediranib (once daily). Cycle 1 was 42 days long with RO4929097 given alone for the first 3 weeks followed by the co-administration of both RO4929097 and cediranib starting from day 22. Cycle 2 and onwards were 21 days long. Soluble markers of angiogenesis were measured in plasma samples. Archival tumour specimens were assessed for expression of three different components of Notch signalling pathway and genotyping.

Results:

In total, 20 patients were treated in three dose levels (DLs). The recommended phase II dose was defined as 20 mg for RO4929097 on 3 days-on and 4 days-off schedule and 30 mg daily for cediranib. The most frequent treatment-related adverse events (AEs) were diarrhoea, hypertension, fatigue and nausea. Eleven patients had a best response of stable disease and one patient achieved partial response. We did not detect any correlation between tested biomarkers of angiogenesis or the Notch pathway and treatment effect. There was no correlation between mutational status and time to treatment failure.

Conclusion:

RO4929097 in combination with cediranib is generally well tolerated at the DLs tested. Preliminary evidence of antitumour efficacy with prolonged disease stabilisation in some patients with progressive malignancies warrants further clinical investigation of this treatment strategy.     

Activated STAT3 is a mediator and biomarker of VEGF endothelial activation

STAT3 plays important roles in cell proliferation and survival signaling and is often constitutively activated in transformed cells. In this study, we examined STAT3 activation in endothelial cells (EC) during angiogenic activation and therapeutic angiogenesis inhibition. VEGF stimulation of cultured EC induced STAT3 phosphorylation by a VEGFR2- and Src-dependent mechanism. FGF2 but not PlGF also induced EC STAT3 activation in vitro. Activated STAT3 mediated VEGF induction of EC Bcl-2 and contributed to VEGF protection of EC from apoptosis. In vivo, p-STAT3 was absent by immunohistological staining in the vascular EC of most normal mouse organs but was present in the vessels of mouse and human tumors. Tumor vascular p-STAT3 increased as tumors were induced to overexpress VEGF, indicating that VEGF is an activator of EC p-STAT3 in vivo. Tumor vascular p-STAT3 decreased during angiogenesis inhibition by antagonists of VEGF-VEGFR signaling, VEGF Trap and SU5416, indicating that VEGF contributed to the EC STAT3 activation seen in the tumors prior to treatment and that p-STAT3 may be used to monitor therapy. These studies show that p-STAT3 is a mediator and biomarker of endothelial activation that reports VEGF-VEGFR2 activity and may be useful for studying the pharmacodynamics of targeted angiogenesis inhibitors.     

Vaccination with autologous endothelium inhibits angiogenesis and metastasis of colon cancer through autoimmunity

Overcoming immune tolerance of tumor angiogenesis should be useful for adjuvant therapy of cancer. We hypothesized that vaccination with autologous endothelium would induce an autoimmune response targeting tumor angiogenesis. To test this concept, we immunized BALB/c mice with a vaccine of glutaraldehyde-fixed murine hepatic sinusoidal endothelial cells (HSEs) in a lung metastasis model of Colon-26 cancer. Vaccination with autologous HSEs induced both preventive and therapeutic anti-tumor immunity that significantly inhibited the development of metastases. ELISA revealed an immunoglobulin response involving IgM and IgG subclasses. These antibodies had a strong affinity for antigens of both murine and human endothelium, and lyzed endothelial cells in the CDC assay. Flow-cytometry and chromium-release cytotoxicity assay revealed a specific CTL response against endothelial cells, which were lyzed in an effector: target ratio-dependent manner. Neither antibodies nor CTLs reacted with Colon26. The effect of autologous HSEs was more pronounced than that of xenogeneic human umbilical vein endothelial cells (HU-VECs), which were tested in the same experimental setting. Our results suggest that vaccination with autologous endothelium can overcome peripheral tolerance of self-angiogenic antigens and therefore should be useful for adjuvant immunotherapy of cancer. (Cancer Sci 2004; 95: 85–90)     

'Accidental' anti-angiogenic drugs. anti-oncogene directed signal transduction inhibitors and conventional chemotherapeutic agents as examples

A number of drugs currently being tested in clinical trials as possible angiogenesis inhibitors were not originally developed with the intention of suppressing tumour angiogenesis. Thalidomide and interferon alpha are obvious examples of such drugs. This list of 'accidental' angiogenesis inhibitors may include established agents such as conventional cytotoxic chemotherapeutic drugs as well as the new generation of anticancer drugs known as anti-oncoprotein signal transduction inhibitors. With respect to the former, the potential of such drugs to inhibit angiogenesis could be the result of their ability to cause collateral damaging effects on cycling endothelial cells found in newly formed blood vessels, or inhibiting other vital endothelial cell functions necessary for angiogenesis. The antitumour vascular side-effects of chemotherapy may be optimised by administering such drugs continuously on a more frequent (e.g. weekly or even daily) basis at levels well below the maximum tolerated dose (MTD), especially when this is done in combination with newly developed anti-angiogenic drugs such as vascular endothelial cell growth factor (VEGF) receptor blocking antibodies. This strategy may minimise or delay the problems of host toxicity and acquired drug resistance. The possibility of anti-angiogenic effects mediated by signal transduction inhibitors such as ras farnesyltransferase inhibitors (ras FTI's), or drugs which block receptor tyrosine kinases (e.g. ErbB2/neu) such as Herceptin, may be the consequence of such oncogenes inducing or upregulating various pro-angiogenic molecules such as VEGF (vascular endothelial cell growth factor) in tumour cells. Hence, treatment of tumour cells with such drugs can lead to downregulation of tumour cell-associated VEGF expression and this can contribute to an anti-angiogenic effect of the drug in vivo. In addition, some of these drugs may also affect certain 'activated' endothelial cell functions directly so as to block angiogenesis. An awareness of the potential of such conventional or experimental anticancer drugs to affect tumour growth through blockade or suppression of angiogenesis has implications for how anticancer drugs may be used clinically, either alone, or in combination with other drugs to optimally treat cancer.     

Circulating levels of vascular endothelial growth factor (VEGF), matrix metalloproteinase-3 (MMP-3), and BCL-2 in malignant melanoma

Vascular endothelial growth factor (VEGF) is a critical regulator of angiogenesis that stimulates proliferation, migration, and metastasis of melanoma. In literature, all studies concerning influences of matrix metalloproteinases (MMPs) and antiapoptotic proteins on VEGF-induced angiogenesis in melanoma patients have been performed in tissue scale in melanoma. The objective of this study was to determine the value of circulating serum VEGF and its possible mechanisms of angiogenesis by circulating VEGF, MMP-3, and Bcl-2 in patients with melanoma. Fifty-one patients with cutaneous melanoma pathologically verified at different stages, and eighteen healthy controls were investigated. Serum VEGF, MMP-3, and Bcl-2 levels were quantitatively analyzed by ELISA. The serum VEGF (P = 0.034) and Bcl-2 (P = 0.005) levels were significantly higher in patients with melanoma than in the control group. However, there was no significant difference in the serum MMP-3 level between melanoma patients and controls (P = 0.51). The serum levels of VEGF were significantly influenced only by Breslow thickness (P = 0.045) and mitosis (0.039) and were not positively correlated with the stage of the disease. Among serum parameters, a significant relationship was found only between serum levels of VEGF and MMP-3 (r = 0.32, P = 0.023). In conclusion, our study demonstrates increased concentrations of VEGF and Bcl-2, but not MMP-3, in serum of melanoma patients regardless of the stage of the disease. VEGF may be a potential endothelial cell growth and survival factor. The mechanism of VEGF regulation of angiogenesis may be in part due to enhanced proliferation and survival of endothelial cells by differential expression of antiapoptotic genes and in part by activation of MMPs.     

Increase of angiogenic growth factors after hepatic artery embolization in patients with neuroendocrine tumours

In the event of diffuse hepatic metastases, hepatic artery embolization (HAE) can be a successful treatment option in patients with well-differentiated neuroendocrine tumours (NET). However, embolization causes hypoxia which stimulates angiogenesis and therefore tumour growth. This study investigates angiogenesis activity following HAE by measuring vascular endothelial growth factor (VEGF), endothelin-1 (ET-1) and C-terminal proendothelin-1 (proET-1) in blood. Twelve patients with well-differentiated NET and liver metastases underwent HAE. VEGF, ET-1 and proET-1 were measured before embolization and the days following treatment during hospitalization. Mean levels during treatment were compared with those at baseline. From 12 patients, 90 blood samples were obtained before and daily for 8 days following HAE. Mean (±SE) VEGF level at baseline was 116 (±33) ng/l which increased after HAE to 313 (±46) ng/l at day 6, followed by a gradual decrease. ProET-1 showed a similar pattern, with a mean baseline level of 9.2 (±2.0) pmol/l and the highest level of 40.8 (±5.7) pmol/l at day 6. Some fluctuations were observed for ET-1, with maximum levels at day 3 compared to baseline levels. In patients with well-differentiated NET who underwent hepatic arterial embolization, angiogenic growth factors increase temporarily. This implies a need to investigate the effect of anti-angiogenic drugs as an adjuvant therapy to embolization.     

Effects of COX-2 inhibition on expression of vascular endothelial growth factor and interleukin-8 in lung cancer cells

Background  

Cyclooxygenase (COX)-2 has been implicated in tumour progression, angiogenesis and metastasis in non-small cell lung cancer (NSCLC). We speculated that inhibition of COX-2 activity might reduce expression of the pro-angiogenic factors vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) in lung cancer cells.     

Peripheral pulmonary nodules: Relationship between multi-slice spiral CT perfusion imaging and tumor angiogenesis and VEGF expression

Background  

The aim of this study is to investigate the relationship between16-slice spiral CT perfusion imaging and tumor angiogenesis and VEGF (vascular endothelial growth factor) expression in patients with benign and malignant pulmonary nodules, and differential diagnosis between benign and malignant pulmonary nodules.