Inhibitors of Angiogenesis in Cancer Therapy

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Current Medicinal Chemistry, 2015, 22, 3830-3847

Inhibitors of Angiogenesis in Cancer Therapy – Synthesis and Biological Activity Monika Gensicka, Agnieszka Głowacka, Krystyna Dzierzbicka* and Grzegorz Cholewinski Department of Organic Chemistry, Gdansk University of Technology, Narutowicza St 11/12, PL 80-233 Gdansk, Poland

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Abstract: Angiogenesis is the process of formation of new capillaries from preexisting blood vessels. Angiogenesis is involved in normal physiological processes, and plays an important role in tumor invasion and development of metastases. Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis. VEGF is a mitogen for vascular endothelial cells and stimulates their proliferation. By inhibiting the biological activity of VEGF, and then signal cascades with neutralizing VEGF antibodies and signal inhibitors, may negatively regulate the growth and metastasis. Anti-angiogenesis therapy is less toxic than chemotherapy. Angiogenesis is a multistep and multifactorial process, and therefore, can be blocked at different levels. In this review article, the authors present the synthesis of novel inhibitors of angiogenesis, together with the results of biological tests in vitro, and in some cases, state trials.

Keywords: Angiogenesis, biological activity, cancer therapy, inhibitors of angiogenesis, synthesis.

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Angiogenesis is regulated by endogenic stimulators, such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), angiopoietins, platelet derived growth factor (PDGF), hepatocyte growth factor (HGF/SF), angiogenin, angiopoietins-1 (Ang-1), platelet-derived endothelial cell growth factor (PDECGF), interleukin-8 (IL-8), insulin-like growth factors (IGFs), prostaglandin E (PG-E), tissue factor (TF), transforming growth factor β (TGF-β) [7-13], and by endogenic inhibitors, such as thrombospondin-1 (TSP-1), angiostatin, endostatin, restin, vasostatin, angiopoietin-2 (Ang-2) and the digestion product of osteopontin [11, 14-16].

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Mostly all of us possess occult, cancerous lesions that for many will not progress to symptomatic disease. Thus, for most people, tumor will become dormant and not progress, while only in some cases will it become a symptomatic disease. Cancer dormancy is defined by stable or very slow tumor growth, which can occur at the cellular level as a malignant cell remaining quiescent for a long period before awakening. The explanation, proposed for tumor dormancy is based on the achievement of a balance between stimulation and inhibition of angiogenesis. This mechanism describes a phenomenon known as concomitant tumor resistance (CR) [1]. CR is a phenomenon in which the growth of secondary tumor implants does not affect the tumorbearing host [2].

As a result of physiological angiogenesis the fully formed functional new blood vessels characterized by the correct shape and size, are regular, and the vascular network has a full differentiation arterio-venous [6]. In the case of carcinogenesis, the newly formed vessels characterized by immaturity with numerous openings along their walls are highly disorganized due to bizarre form [3].

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1. INTRODUCTION

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Angiogenesis is a process based on the formation of new blood capillaries from pre-existing vessels [3, 4]. It is not only involved in normal physiological processes such as pregnancy, organ development, menstrual cycle and wound healing, but also plays a crucial role in tumor growth, invasion and development of metastasis [3, 5]. *Address correspondence to this author at the Faculty of Chemistry, Department of Organic Chemistry, Gdansk University of Technology, G. Narutowicza St 11/12, 80-233 Gdansk, Poland; Tel: (48 58) 347-20-54; Fax: (48 58) 347-26-94; E-mail: [email protected] 1875-533X/15 $58.00+.00

The process of angiogenesis is also facilitated by enzymes proteolytic extracellular matrix, fibrinolytic factors, and integrins [11, 17]. Of the many the above-mentioned factors stimulating angiogenesis process vascular endothelial growth factor (VEGF) plays a key role [18]. It regulates both © 2015 Bentham Science Publishers

Inhibitors of Angiogenesis in Cancer Therapy

Current Medicinal Chemistry, 2015, Vol. 22, No. 33

Sunitinib (2), sorafenib (3), and pazopanib (4) (Fig. (1)) inhibit the VEGFR. Pazopanib (4), a synthetic indazolyl pyrimidine, is a multitargeted tyrosine kinase inhibitor with antiangiogenic activity, mainly due to VEGFR2 pathway interference. It showed highly significant dose-dependent tumor growth inhibition by pazopanib in vitro (4) in a wide variety of tumor xenografts (i.e. colon, melanoma, prostate, renal, breast, lung and multiple myeloma). Pazopanib (4) demonstrated high activity towards renal cell carcinoma (RCC), and other malignancies, such as hepatocellular carcinoma (HCC), non-small cell lung cancer (NSCLC), ovarian cancer, and multiple myeloma [3].

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An important step in the process of angiogenesis is the proliferation and migration of endothelial cells, which is governed mainly by VEGF. It is responsible for the survival and cancer cell invasion. Through inhibition of VEGFR and FGFR and direct effects on the process of proliferation and migration of endothelial cells, disruption of these processes is possible, so there are no chances of the growth and spread of cancer cells [22].

been found desirable for the treatment of severe tumor angiogenesis [25]. Thalidomide is used to treat refractory or recurrent and untreated multiple myeloma [26, 27].

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physiological and pathological angiogenesis has been demonstrated that it plays an important role in development of angiogenesis-dependent diseases [19]. VEGF is a mitogen for vascular endothelial cells and stimulates their proliferation [20]. Tumor angiogenesis is essential to supply metabolic requirements for tumor cell proliferation as well as metastasis. Therefore, inhibiting the biological activity of VEGF and then signal cascades with neutralizing VEGF antibodies and signal inhibitors probably negatively regulate tumor growth and metastasis [21].

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Anti-angiogenesis therapy is less toxic than classic chemotherapy and does not cause drug resistance, but it can cause myelosuppression, hair loss and gastrointestinal ailments. Angiogenesis is a multistep and multifactorial process, therefore, it can be blocked at different levels [24]. 2. INHIBITION OF ANGIOGENESIS

The first formulation used to inhibit angiogenesis was thalidomide (1) (Fig. (1)). This medicine has been synthesized and introduced to the treatment in the 50’s. In 1961, McBride and Lenz proved that oral administration of thalidomide causes deformation of the fetus because thalidomide is a chiral compound. It was administered as a mixture of enantiomers in a ratio of 50:50, and one enantiomer causes birth defect. In the 90's it was demonstrated that antiangiogenic action has

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Young et al. [29] studied to determine the potential effects of vascular-targeted agents for the treatment of angiosarcoma, using two human cutaneous angiosarcoma cell lines (ASM and ISO-HAS), and human dermal microvascular endothelial cells (HuDMECs) for comparison. The answer to the vascular targeted factors includes several agents, such as bevacizumab (recombinant humanized monoclonal antibody) an anti-VEGF antibody, axitinib (5) a VEGF-receptor tyrosine kinase inhibitor, everolimus (6) an mTOR inhibitor, selumetinib (7) an MEK inhibitor and vadimezan (8) (Fig. (2)) and a vascular-disrupting agent. These responses were comparable within in vitro assays, including viability, differentiation and migration assays. It has been found that ASM and ISO-HAS VEGF expression was significantly increased (p = 0.029) as compared with HuDMECs. Vadimezan (8) inhibited ASM and ISOHAS cells with IC50 value of 90-150 µg/ml. Young group [29] investigated that selumetinib (7) inhibited ASM with IC50 value of 1.750 ng/ml, but in relation to the ISO has not demonstrated activity. Studies have shown that everolimus (6) reduced both ASM and ISOHAS viable cell counts by 20%. In the case of bevacizumab and axitinib (5) minimal responses were observed in assays with ASM and ISO-HAS cells.

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Prasadam et al. [23] research shows that there is an important role of osteocytes in regulating angiogenesis, namely, during bone formation osteocyte dendritic processes are closely associated with blood vessels. The conditioned media (CM) created from MLOY4 cells-activated proliferation, migration, tube-like structure formation, and upregulation of angiogenic genes in endothelial cells indicate that secretory factor(s) from osteocytes could be responsible for angiogenesis. It was also found that the VEGF excreted in MLOY4 activated VEGFR2-ERK-MAPK-signaling pathways in HUVECs. In HUVEC cells, inhibition of VEGF and / or MAPK-ERK pathways abrogated osteocytemediated angiogenesis [23].

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Thomeas group [28] showed that after exposure to sorafenib (3), repeated measures linear modeling from 15 patients indicated increased angiopoietin-2 (Ang2) (P0.05) and decreased sVEGFR2 antibody (P0.05). Furthermore, VEGFA has a high intraindividual variance, and testing in the laboratory showed a significant effect on the measurement of plasma (P0.05). Biological reproducibility of sVEGFR2 and Ang2 supports the continued use of these markers in the research of vasculature-targeted therapeutics [28].

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It was found that obtaining a complete response (CR), positively influences the survival of metastatic patients. CR in metastatic renal cell cancer (mRCC) treated with antiangiogenic agents (AAs) is a rare

event. The percentage of patients reaching CR in the registration studies for sunitinib (2), sorafenib (3), pazopanib (4), and bevacizumab was less than 3%, these results have often been achieved by integrating medical



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Fig. (3). Structure of fasudil (9), semaxanib (10), LY2801653 (11) [24, 33, 34].

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Cetuximab is an antibody molecular connecting EGFR, HER1 or c-ErB-1 used in metastatic colorectal cancer expressing EGFR in combination with irinotecan in the case of resistance to irinotecan [24]. LY2801653 (11) (Fig. (3)) is dual kinase inhibitor with potent activity against MET/RON. Inhibition of MET and RON was associated with decreased phosphorylation of CBL, PI3K, and STAT3. In classic and orthotopic mouse xenograft models of lung cancer, LY2801653 (11) decreased tumor growth, dramatically inhibiting mitotic events and angiogenesis. Specific targeting of the MET/RON kinases could provide robust inhibition of cell proliferation and tumor outgrowth in multiple in vitro and in vivo models of NSCLC [34].

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Neoadjuvant therapy could provide a reduction of neoplastic mass and, by consequence, result in the needed for a less aggressive surgery, thus ensuring better residual renal function or pave the way for a potentially radical surgery of the metastatic sites and better oncological results. Neoadjuvant therapy is more effective on small sizes (especially those smaller than 7 cm), which undergo significant reduction, which positively affect surgery. Moreover, CR in these experiences is quite rare. This proves that available therapies for firstline treatment of mRCC are ineffective at increasing rate of CR. However, the introduction of AAs has significantly changed the life expectancy of patients with mRCC, as ORR and PFS have been improved since these were introduced in clinical practice [32].

AML purine analogs such as fludarabine or cladribine, are also used which in addition to the cytostatic action are likely to act by inhibiting neovascularization in the bone marrow [24].

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treatments with surgery, radiotherapy, or both. Albiges et al. [30] reported the largest series of patients with mRCC experiencing CR during tyrosine-kinase inhibitor (TKIs) treatment either alone or in combination with local treatment. The study reports a higher rate of relapse in patients who stopped therapy after CR as compared to patients who discontinued TKI treatment after further cycles or those who continued therapy. Johannsen et al. [31] reported that CR may be reached using only medical therapy in 1.8% of the cases and with the use of TKIs and surgery in 4.5% of the cases. The mechanism of action of antiangiogenic agents seem to have been more cytostatic than cytotoxic, which from a pharmacological point of view gives the unsatisfactory results of AAs to induce CR [32].

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Celik and co-workers [33] studied the influence of an intravitreal injection of bevacizumab and fasudil (9) (Fig. (3)) on the retinal vascular endothelial growth factor (VEGF), tumor necrosis factor alpha (TNFα), and caspase-3 levels in a diabetic rabbit model. The study included four groups of rabbits. Between the groups was a statistically significant difference in VEGF and caspase-3 levels, but the TNF level did not differ significantly between groups. The authors found that the level of VEGF was significantly lower in the groups 1 and 3 then group 2. It has been found that injection of bevacizumab reduces VEGF level which plays a role in angiogenesis and the level of caspase-3, involved in apoptosis. Fasudil (9) proved to be less effective than bevacizumab. It was found that fasudil (9) also exerts a beneficial effect on VEGF, but greatly increases the caspase-3 levels [33].

Semaxinib (10) (Fig. (3)) characterized by inhibition of VEGFR-1, VEGFR-2 and c-kit, SU6668 inhibits VEGF receptors, FGF, and PDGF; they are tested in the treatment of AML and MM. For the treatment of

Serine-threonine protein kinase Akt plays a very important role in the signal transduction pathway-3kinase (PI3K). It is also responsible for regulation processes concerning growth, proliferation, metabolism and survival of cells and influences the process of tumor angiogenesis and expression of HIF-1α, VEGF [35-37]. The neovascularization contributes to the endothelial cell response to angiogenic factors, cell migration and maturation of newly formed blood vessels. Akt activation may be triggered by cells of insulin, cytokines, or under the influence of growth factors: bFGF, VEGF, and HGF [35]. By attaching an appropriate ligand to the receptor tyrosine kinase reaches its activation following its autophosphorylation and re-


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produced compound (13b) having similar activity to PI3Kα and stability under the same conditions. A series of structurally similar compounds containing heterocycles was prepared. Good tolerance was characterized by inter alia compound (13c) comprising a tetrazole ring (IC50 = 0.8 nM). Similarly, derivatives (13d) and (13e) exhibited proper enzyme potential and showed good activity in the inhibition of endothelial cell proliferation. Selected compounds showing inhibition against PI3K were also tested for activity halting the proliferation of breast cancer tumor cells, such as T47D, SK-BR3 and MCF7 cells. The test was performed by MTT. Analogs (13a), (13b) and (13f) were characterized by a good capacity for inhibition. Furthermore, these inhibitors exhibited considerable apoptotic and antiangiogenic effects by inhibiting VEGF expression [41]. Structures of compounds (13a-f) are shown in Fig. (5).

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cruitment to the plasma membrane by phosphatidylinositol 3-kinase [35]. PI-3K converts PIP2 to PIP3, which is necessary for activation of Akt kinase. In humans cancer can be observed to increase its activation due to gene Akt amplification as demonstrated in the cases of glioma, tumors of the head, neck, stomach, ovary, prostate and breast cancers [35]. Increased activity of Akt may also result from increased gene amplification PI-3K, loss of activity of phosphatase PTEN is due to dephosphorylated phospholipids inositol and activation or mutations of receptor kinases and oncogene [38]. PIK3CA gene encoding catalytic subunit of the kinase PI-3K is often mutated and overexpressed in large parts of the tumor cancers such as hepatocellular carcinoma, ovarian, breast, stomach, thyroid or colorectal cancer [37]. These observations suggested that the PI-3K pathway comprising PTEN inactivated angiogenesis stimulating factors and tumor growth by controlling the expression of VEGF and HIF-1 [39]. Therefore, the inhibition of the PI3K/Akt may be an important factor in cancer therapy [40].

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Kim et al. [41] synthesized series of imidazo-[1,2a]pyridine derivatives as potent PI-3KR inhibitors. All the obtained compounds were tested for the ability to block kinase PI3K using the method KINOmescan. Compound (12) (Fig. 4) showed the greatest inhibition ability. Thus, (12) was further optimized and modified by introducing at the C3 position of the respective groups, e.g. nitrile, carbonyl, ester or substituted aromatic rings. In order to increase the diversity of structure in the C6 position different groups of sulfonamide were introduced (Me, Ph, substituted benzene, heterocycles and revered sulfonamide).

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Chen et al. [40] provide new evidence that JWA (a multifunctional microtubule-binding protein) inhibits tumor angiogenesis in gastric cancer (GC). Two independent retrospective GC cohorts found that expression of JWA was reduced and that MMP-2 was increased in GC tissues when compared with the gastric mucosa. In patients treated only with surgery it was noted that JWA was reduced and expression of MMP-2 was increased, a stronger effect was obtained with the combined treatment. In addition, Chen et al. [40] investigated, that loss of expression of JWA is closely linked with the increase in angiogenesis GC. In vitro studies revealed that JWA inhibited MMP-2 at the level of RNA and proteins by modulating Sp1 activity. Knockdown of endogenous JWA resulted in enhanced human umbilical vein endothelial cell tube formation and MMP-2 expression. Studies also show that JWA inhibits the activity of Sp1 through the mechanism of ubiquitin-proteasome-dependent as well as the expression of proangiogenic regulation of MMP-2 [40].

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Fig. (4). Structure of compound (12) [41].

Compound (13a) was proved to be the most effective inhibitor. However, it was unstable and decomposed within 48 hours at 40°C in phosphate buffer (pH = 6.7). Perhaps this was due to hydrolysis of the ester bond. Therefore, bioisosteric groups were sought that produced an ester bond with greater stability and capacity to block the PI3K. Conversion of the ester group in the compound (13a) to bioisosteric 1,2,4-oxadiazoles

Yu group [42] defined that bradykinin (BK) promotes prostate cancer angiogenesis via VEGF expression. This study showed that the expression of BK is associated with an angiogenic phenotype in prostate cancer cells. Both types of BK receptors as B1 and B2 have been defined and cloned. The results suggest that the BK B2 receptor plays a key role in mediating the metastatic in human prostate cancer cells. The study showed pretreatment of prostate cancer cells with Akt or mTOR inhibitor antagonizing BK-induced increase in VEGF expression. Moreover, treatment of prostate cancer cells with BK increased mTOR phosphorylation. The resulting effect is due to inhibition of Akt



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Hu and co-workers [44] synthetized peptides CPU1 and CPU2, by connecting Regasepin2, a heptapeptide inhibitor of matrix metalloproteinases (MMPs), to the N- or C-terminus of ES-2, an antiangiogenic undecapeptide. The resulting compound CPU1 exhibited less inhibition than Regasepin2 against TACE, MMP-8 and MMP-9, while CPU2 inhibited the activity of MMP-8 and MMP-9 in the nanomolar range. Furthermore, CPU1 has a higher affinity than CPU2 with integrin α5β1 in the HUVEC adhesion assay. CPU1 also has a higher potential than CPU2 inhibition (85% inhibition for CPU1 at a concentration of 0.8 mM, 17% inhibition for the CPU2 at the same concentration) in an in vitro model of angiogenesis. In in vivo model of angiogenesis in chicken egg chorioallantoic membranes CPU1 showed strong potential to inhibit the formation of new blood vessels. These studies also showed that Regasepin2 and CPU2 showed no effect on angiogenesis. Hu et al. [44] also found that CPU1 greatly inhibited B16F10, the growth of melanoma growth in a syngeneic mouse model (inhibition rate of 56.91% by tumor weight analysis at a dose of 20 mg/kg/d). Regasepin2 and CPU2 did not show inhibitory activities of growth of melanoma [44].

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inhibitor. The results suggested that NF-kB and AP-1 activation contributes to BK-induced VEGF expression in human prostate cancer cells. BK increased NF-kB and AP-1 promoter activity. In contrast, NF-kB and AP-1 promoter activity is reduced during pretreatment of cells with HOE140, Akt inhibitor, and rapamycin. These results showed that BK may act through the B2 receptor and Akt, mTOR, and NF-kB/AP-1 pathways to induce VEGF expression in human prostate cancer cells [42].

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Fig. (5). Structures of novel synthetized compounds (13a-f) [41].

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Chen et al. [43] examined the expression of RUNX3 in relation to clinicopathologic features using prostate cancer. Collected clinical trial results exhibited that RUNX3 is lost in prostate cancer and correlates with the progression of the TNM stage. RUNX3 suppresses prostate cancer metastasis due to the imbalance between MMP-2 and TIMP-2. Whereas in vitro studies have shown that the RUNX3 in prostate cancer cells reduces cell migration, invasion and angiogenesis ability, which was consistent with the function of RUNX3 in vivo. It was also found that the expression of RUNX3 is lost in prostate cancer tissue in the last stage. Collected clinical evidence confirmed that the modified RUNX3 expression contributes to the development and metastasis of prostate cancer. Studies have shown that RUNX3 has no effect on proliferation of prostate cancer cells in vitro and inhibited tumor growth in an animal model. The authors of this article, on the basis of the results of in vitro and in vivo studies have found that RUNX3 inhibits tumor growth by inhibiting tumor angiogenesis. VEGF was decreased by restoration of RUNX3 in prostate cancer cells [43].

Puxeddu et al. [45] studied the entanglement of endostatin (ES) and thrombospondin-1 (TSP-1) in patients with chronic spontaneous urticaria (CSU). The authors measured the levels of ES and TSP-1 in sera of 106 adult patients with CSU and 98 healthy subjects by enzyme immunoassays. The serum levels of the antiangiogenic mediators ES and TSP-1 resulted significantly higher in the CSU than in control subjects. For the


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Vasohibin-1 is a negative feedback regulator of angiogenesis induced by VEGF-A. Vasohibin-1 and VEGF-A proteins were expressed in 88.6 % (117/132) and 84.1 % (111/132) colorectal cancer tissues, respectively. Yan group [46] found strong positive correlations between Vasohibin-1, VEGF-A expression, and MVD in the colorectal cancer tissues (Vasohibin-1 vs. VEGF-A: r = 0.7, P < 0.001; Vasohibin-1 vs. MVD: r = 0.5, P < 0.001; VEGF-A vs. MVD: r = 0.5, P < 0.001). Vasohibin-1 expression has significant positive correlation with pathological TNM stage (P = 0.001), tumor stromal invasion (P = 0.004), lymph node status (P = 0.003), and distant metastasis (P = 0.033). However, Vasohibin-1 expression did not show any correlation with tumor differentiation (P = 0.756). Vasohibin-1 is a clinically relevant predictor of patient prognosis in colorectal cancer, because its expression is an independent risk factor affecting OS and PFS. Vasohibin-1 might become a new biomarker and provide additional prognostic information of patients with colorectal cancer [46].

conserved ATP binding sites for the kinases [49]. Nintedanib (14) also targeted in the assay of the triple angiokinase inhibition, which increases the efficiency of the drug. Nintedanib (14) characterized by the lack of induction of epithelial-mesenchymal transition implicated in antiangiogenic therapy that despite resistance causes hypoxia [50]. Nintedanib (14) also exhibits higher activity against FLT3, KIT, and the Src family. So far it is not known why the combination of pemetrexed plus nindetamid improves PFS as compared with the pemetrexed. In this case, there no major differences were observed in the overall survival in 713 patients in studies of LUME-Lung 2 before its early termination [51]. This may be due to specific efficacy chemotherapy drug or imbalances in genomic profiles or biomarkers that are not available from the reported studies - a major limitation.

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analysis of mediators in a subgroup of patients with CSU used autologous serum skin test (ASST). A significant increase of ES and TSP-1 in ASST-positive and ASST-negative subgroups was identified as compared to the controls. The level of ES and TSP-1 was not commensurate with the severity of the disease in the CSU. This research indicated that the extracellular matrix (ECM) fragments ES and TSP-1 with antiangiogenic activity play important role in the pathogenesis of CSU but not in the intensification of the disease [45].

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Reck group [47] describes the results of LUMELung 1, phase 3 double-blind, randomized patients to second-line docetaxel (15) plus placebo (n = 659) or docetaxel (15) plus nintedanib (14) (n = 655) (Fig. 6). Nintedanib (14) is a tyrosine kinase inhibitor (TKI) targeting VEGFR1-3, platelet-derived growth factor receptor (PDGFR) α and β, fibroblast growth factor receptor (FGFR) 1-3 [48]. The study proved that the addition of nintedannib (14) to docetaxel (15) highly ameliorates progression-free survival (PFS) in the total study population. It was also noted to significantly improve the survival of patients with adenocarcinoma, but it does not apply to the entire population. The combination of docetaxel plus nintedanib turned out to be well tolerated. The most common adverse effects are gastrointestinal problems and elevated liver enzymes. Most of the VEGFR-TKIs also inhibit several other targets, containing PDGFR and KIT. This is due to well-

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A defect of previously used angiogenesis inhibitors is the presence of numerous side effects during drug administration. These include hypertension, proteinuria, bleeding, gastrointestinal perforation, impaired wound healing, and arterial and venous thromboembolism. Various studies indicate different frequency data and a deterioration due to side effects of the same classes of molecules used in various types of cancer. As mentioned above, VEGF plays a central role in the regulation of angiogenesis and blocking of VEGF pathways which are the main objectives in halting tumor growth. Unfortunately, as mechanisms of inhibition of apoptosis, vasodilation / vascular permeability, reduced vessel density are also major causes of toxicity of anti-VEGF agents. One of the most serious side effects of anti-angiogenic drugs, which may be life threatening is bleeding. According to previous studies, bevacizumab has the highest incidence of bleeding complications, including epistaxis, hemoptysis, hematemesis, gastrointestinal or vaginal bleeding, and brain hemorrhage. This situation encourages scientists to look for new, less toxic angiogenesis inhibitors [53].

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Mansfield and Markovic [52] summarize the clinical studies of angiogenesis inhibitors for the treatment of metastatic melanoma taking into account the overall response rate (ORR), overall survival (OS) and progression-free survival (PFS). They stated that antiangiogenic agents that were tested exhibited low activity as single agents. At present, antiangiogenic therapies are mainly available as clinical trials. A very large amount of research is in progress, which will enable to define the role of inhibition of angiogenesis in the treatment of metastatic melanoma [52].



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TP inhibitory activities is very much dependant on the nature and position of substituents in the R1 and R2. Compound (21) (R1=4’methylphenyl R2=2”methoxy-5”-nitrophenyl) bearing the nitro moiety was found to be the most strong between the tested oxadiazoles with an IC50 value 14.40 ± 2.45 µM which is about 2.5fold more active than 7DX. Molecular modeling has exposed the importance of nitro group in the most active compound (21), which can possibly create Hbonds with Arg171 and Ser186 [54].

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Overexpression of VEGFR-2 is nearly involved in angiogenesis of solid tumors. Hence inhibitors of VEGFR-2 are capable of treating a tumor relative of angiogenesis. Wang group [55] synthesized new biphenyl derivatives including urea and analyzed their potential to inhibit VEGFR-2 (vascular endothelial growth factor receptor-2). Synthesis of the resulting compounds was depicted in Scheme 2 [55].

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Shahzad et al. [54] synthesized the new derivatives of 1,3,4-oxadiazole-2-thiones (18) as potent thymidine phosphorylase (TP) inhibitors (Fig. 7). The newly designed oxadiazoles contain N–H, C=N, O and CS groups and R substituents which may interact to the active sites of enzyme (His85, Ser186, Lys190, Arg171, Tyr168, Phe210) in a similar pattern like TPI. 7DX was used and considered as a reference compound in the current in vitro TP inhibition studies [54].

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3. SYNTHESIS OF THE NOVEL ANGIOGENESIS INHIBITORS

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Fig. (6). Structures of nintedanib (14) and docetaxel (15) [27].

Proposed 1,3,4oxadiazole-2-thione derivatives

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Fig. (7). Chemical structure of known TP inhibitors-TPI and 7DX and proposed 1,3,4-oxadiazole-2-thione derivatives (18) as new class of TP inhibitors [54].

In this research, a series of new 1,3,4-oxadiazoline2-thione derivatives (18) bearing other level of substituents were obtained according to synthetic pathway given in Scheme 1 [54]. All prepared compounds were active and showed TP inhibition with IC50 values ranged between 14.40 ± 2.45 and 173.23 ± 3.04 µM. 7-Deazaxanthine was used as a standard inhibitor. A number of derivatives have been found to be more active as compared to reference compound 7DX. Structure-activity relationship (SAR) displayed that the increase or decrease in

The structures of the obtained compounds are given in Fig. (8). Most of the resulting chemicals revealed a moderately potent inhibitory activity with an IC50 value in the range of 4.06 to 179 nM. The most effective compounds were proved to be (34a), (34b) and (34c), and their inhibitory activity for the VEGFR-2 with an IC50 values were 4.06, 4.55 and 5.26 nM [55]. Compound (34a) also exhibited good results in activity against K562, SY5Y and LoVo cell line. SAR studies revealed that methyl at 2-position of terminal aniline could improve biological activity. Favorable results were obtained on substituting aminoalkoxy group in the 4-position to the urea group. The most preferred substituents on the phenolic group attached to the urea group are 3-N,N-dimethylpropoxy, 3morpholinopropoxy, and 2-piperidin-1-yl-ethoxy group. Docking studies demonstrated four hydrogen


Gensicka et al. NO2

O NHNH2

N

Microwave irradiation

OCH3

HCHO, EtOH

S

O

NH N

NO2

CS2, KOH, Al2O3

H3C

NH

H3C

19

N S

O

20

OCH3

NH2

21

H3C

Scheme 1. Synthetic protocol of 1,3,4-oxadiazoline-2-thione derivative (21) [54].

O

CHO

b

O

22

HO

c

O

CHO

24

23

Br AcO f

Br

Br

O

30

R2

U

O

Br

O

O

N H

k H2N

R3

on al

N H

31

34a 34b 34c

NH2

27 O

O

i O

B

O

32

O

O

O

j

O

33

O

tri

O

CONH2 O

26

h

g

29

28

O

O

se

HO

O

CN

25

O

OH

O

CN

e

d

O

bu tio n

HO

a

Br

O

O

nl y

HO

Br

Br

Br

Br

O

B A

is

rD

R3 = 4-O

N

C

N H

R3

34b: R1 = COCH3, R2 = CH 3, R3 = 4-O

N

34c: R1 = COCH 3, R2 = CH3, R3 = 4-O

N

R2

N

R1

N H

O

ot

O

O

34a: R1 = COCH 3, R2 = H,

O

Fo

Pe rs

Scheme 2. Synthetic route of biphenyl ureas. Reagents and conditions: (a) Br2, AcOH, AcONa, Fe, rt; (b) HCOOH, HCOONa, (NH2OH)2•H2SO4, 90°C; (c) (CH3O)2SO2, K2CO3, Me2 CO, 50°C; (d) NaOH, H2O2, EtOH, 60°C; (e) Br2, NaOH; (f) Py, Ac2O, rt; (g) AlCl3, 160°C; (h) (CH3O)SO2, K2CO3, acetone, 50°C; (i) bis(pinacolato)diboron, dioxane, Pd(pddf)Cl2, KOAc, 100°C; (j) Pd(pdf)Cl2, Na2 CO3, H2O, dioxane, 100°C; (k) triphosgene (BTC), anilines, Et3N, DCM, rt. [55].

Fig. (8). Structures of compounds 34a-c [54].

bondings between the urea unit, and the active site of VEGFR-2. Wang group [55] studies have confirmed that urea is important for biological activity. Gabapentin 1-(aminomethyl)cyclohexane acetic acid (Gbp 1) (35) is used for the treatment of epilepsy, neuropathic pain, restless legs syndrome, anxiety disorders, hot flushes and numerous other conditions. Gbp 1 easily undergoes facile intramolecular cyclization to obtain the five-membered cyclic lactam 2-azaspiro[4,5]decan-3-one (36a) (Scheme 3) [56].

O NH2 OH

35

NH O 36a

Scheme 3. Intramolecular cyclization of Gbp into 2azaspiro[4,5]decan-3-one (36a) [56].

Lebedyeva et al. [56] presented the synthesis of Gabapentin analogs by N-acylation at its N-terminus



nl y

sized by alkylation of the methyl vanillate with chloroalkane and potassium carbonate in acetone. Following nitration with mixture of nitric acid and tin tetrachloride in dichloromethane afforded nitro derivatives (5254). As a result of catalytic hydrogenation of the nitro group in the presence of Raney® nickel obtained amino derivatives (55-57) which were converted by cyclization with formamide in the presence of ammonium formate to give the cyclized compounds (58-60). Finally, compounds (58-60) were reacted with phosphorus oxychloride to obtain the intermediates 4-chloroquinazolines (61-63). The intermediates 4chloroquinazolines 54 and 55, belonging respectively to series A and B, were prepared starting from methyl vanillate and methyl 3,4-dihydroxybenzoate, respectively according to the described procedure [56]. The corresponding ureas (68-70) were obtained by condensation 4-aminophenols (66) with 3-bromophenylisocyanate (67) in pyridine at room temperature in high yields and short time reaction (Scheme 9). The desired final products were obtained by the reaction of chloride derivatives (51-55) with appropriate N,N’diphenylurea (68-70) in presence of tetra-N-butylammonium bromide in butan-2-one and 20% solution of sodium hydroxide mixture (Scheme 10) [57].

bu tio n

is

tri

All synthesized compounds were assayed for inhibition of tumor cell growth and angiogenesis. These derivatives show a nanomolar inhibition of kinase enzymatic activity of VEGFR, PDGFR-ß and c-Kit (IC50 values at nanomolar range). Varying the methoxy groups on the 7-position of the quinazoline scaffold by addition of a basic side chain (diethylamino- alkoxy, piperidino-alkoxy or pyrrolidino-alkoxy) led to new highly potent ATP-competitive inhibitors of VEGFR, PDGFR-ß and c-Kit enzyme, which not only exhibited significant antiproliferative activities on cancer cell lines (PC3, MCF7, HT29) and HUVEC (human umbilical vein endothelial cells), but possess lower proliferation inhibition against the normal cells MRC5. The most promising compound is derivative (83), a multikinase inhibitor which strongly represses the angiogenic process by inhibiting endothelial cell invasion and preventing tube formation with lower concentrations than those of the reference compound (cediranib) [57].

rD

Pe rs

on al

U

se

O

into di-, tri-, and tetrapeptides (L-Ala-Gbp, L-Val-Gbp, L-Ala-L-Phe-Gbp, Gly-L-Ala-β-Ala-Gbp) (Scheme 4). Deprotection of Cbz and Boc groups did not induce the intramolecular cyclization of products (42a,d) [56]. They have also developed CO conjugates of gabapentin with S-, O-, and N-nucleophiles. As a protection of the amino group of Gbp, Boc-protection was used. To synthesize compounds (44a,c) the authors tried coupling methods such as DCC, DCC/HOBt and isobutyl chloroformate/N-methylmorpholine. The use of isobutyl chloroformate allowed a preparation of Gbp conjugates (44a,c) with no racemization or intramolecular cyclization and gave a high yield (Scheme 5). Deprotection of Boc-group with HCl saturated MeOH solution producing stable C-terminus gabapentin bioconjugates as hydrochlorides (45a-c) (Scheme 5) [56]. The L-menthol was used to produce (43a) and cholesterol was used to produce (46b) through isobutyl chloroformatemediated reactions, resulting in optically pure products with no detectable amount of (36b). In this way they were able to introduce two bioactive moieties into the N-protected gabapentin through O-acylation reactions (Scheme 6) [56]. During the reaction, thiophenol and cysteinyl L-phenylalanine methyl ester with N-Boc Gbp (40c) by using isobutyl chloroformate afforded (47a) and (44b) (Scheme 7). Thus, the problem of gabapentin intramolecular cyclization into γ -lactam was avoided by conjugating the drug at its C- and Ntermini to the bioactive nucleophilic moieties and peptides [56].

3839

N

ot

Fo

Compounds (35, 42a, 45c) were tested in in vivo mouse models for pain relief. During injecting compounds (35, 42a, 45c) and/ or vehicle solutions (65% EtOH, d-H2O), all the animals behaved normally. There was no significant effect of treatment on reward licking events for compounds (35, 42a, 45c) as compared to the vehicle (65% EtOH) control group. No severe adverse events were reported up to 3h following injection of the compounds or the vehicles [56]. Ravez and co-workers [57] reported the synthesis of series of novel quinazoline compounds distinguished by the nature of the ether linker at the C-6 and C-7 positions of the quinazoline core: 6-butoxy-7-diethylaminoethoxy- (series A); 6-methoxy-7-diethylaminoethoxy- (series B); 6-methoxy-7-piperidinoethoxy- (series C); 6-methoxy-7-pyrrolidinoethoxy(series D) and 6-methoxy-7-piperidinopropoxyquinazoline (series E) (Fig. 9). The intermediates 4-chloro-7-aminoalkoxyquinazolines were prepared in five steps for series C, D and E (Scheme 8). Compounds (49-51) were synthe-

Xu et al. [5] presented the synthesis of N-(3-((7Hpurin-6-yl)thio)-4-hydroxynaphthalen-1-yl)sulfonamide derivatives. The procedure for the preparation of the target compounds (90a-p) is shown in Scheme 11. In a first step, hydroxyl group was introduced into nitronaphthalene (85) by using t-BuOOH and KOH. Sub-


Gensicka et al. O

O HN-Ala-L-Cbz

HN-Ala-L

OH ii

Cbz-L-Ala-Bt 37

41a

H2N

42a

O

HN-Val-L-Cbz O

OH

O

HN-Val-L

OH

Cbz-L-Val-Bt

OH

ii

38

OH

41b

i

nl y

OH

iii

Boc-L-Ala-L-Phe-Bt 39

O

Ha-Nβ-Al-AlaL-Gly-Cbz

O

Ha-Nβ-Al-AlaL-Gly

OH

se

bu tio n

OH

Cbz-Gly-L-Ala-β-Ala-Bt

ii

42d

41d

U

42c

O

41c

40

O

HN-Phe-LD-Ala-LD*ClH OH

HN-Phe-L-Ala-L-Boc 35

42b

O

Boc-HN

Pe rs

ii

O

i

tri OH + N-Nu

O

O

Boc-HN

43

NH

NH

O

O O

NH

O

O ii

N H

HClH2N

N H

45b

44b

i

O

Boc-HN

ot

i = N-methylmorpholine, ClCO2CH2CH(CH3)2, THF, rt, 24 h ii = MeOH/HCl, rt, 2 h

i

HN

44a

45a

O

Boc

N H

is

O

O

N H

Fo

O HClH2N

O

rD

O

on al

Scheme 4. Synthesis of conformationally restricted Gbp-terminus peptidomimetics (42a-d). Reagents and conditions: (i) Et3N, MeCN/H2O rt, 16 h; (ii) 10% Pd/C, H2, MeOH, rt, 8 h; (iii) MeOH/HCl, rt, 2 h [56].

N H

O ii

HClH2N

N H

45c

44c

Boc HN

O O

N

Scheme 5. Synthesis of C-terminus gabapentin conjugates bearing N-nucleophilic moiety [56].

i

Boc HN

O OH + O-Nu

Boc HN i

O O

H H H

46a

43

46b

i = N-methylmorpholine, isobutyl chloroformate, N2, rt, 24 h

Scheme 6. Synthesis of C-terminus gabapentin conjugates bearing an O-nucleophilic moiety [56].

H

NH

O


Current Medicinal Chemistry, 2015, Vol. 22, No. 33 Boc

O

Boc HN

i

S

Boc HN

O OH + S-Nu

and

O

S

O

HN 43

i = N-methylmorpholine isobutyl chloroformate, N2, rt, 24 h

47a

O N

O

Boc HN

36b

O HN

47b

3841

Cbz

Scheme 7. Synthesis of C-terminus gabapentin conjugates bearing an S-nucleophilic moiety [56].

6

N

Series C: R1 =

O

X=H, CH3 or Cl

Series D: R1 =

7

N

R2 =

N

O

R2 =

N

O

U

R2

O

on al

Series E: R1 =

O

O

48

O

O ii

R

49-51

52-54

61: R =

NO2

R

62: R =

ot

O

O 55-57

NH2

R

NH 58-60

N

v

O

Cl O

N

O

O

N

O R

N

63: R =

O

O

O

O

N

O

iv

Fo

N

N

O

O iii

is

R

Pe rs

HO

O

O i

O

O

N

R2 =

rD

O

R2 =

tri

Fig. (9). A series of novel quinazoline analogs [57].

O

bu tio n

R1

X

Br

se

O

Series B: R1 =

H N

N

O

O

H N

R2 =

nl y

Series A: R1 =

61-63

N

Scheme 8. Reagents and conditions: (i) aminoalkyl chloride, K2 CO3, acetone, reflux; (ii) HNO3, SnCl4, CH2Cl2, -70 °C; (iii) Raney® Ni, H2, MeOH/CH2Cl2, rt; (iv) HCONH2, HCOONH 4, reflux; (v) POCl3, reflux [57]. O

C

NH2

N

Br

+ HO

66

X 67

H N

i HO 68: X=H 69: X=CH3 70: X=Cl

Scheme 9. Reagents and conditions: (i) pyridine, rt, nitrogen atmosphere [57].

X

H N O 68-70

Br


Gensicka et al. H N

Cl R1

N

R2

N 61-65

H N + HO

X

Br

i

O

R1

N

R2

68-70

71-84

Br

O

X

O

H N

H N

Series A 71: X=H, 72: X=CH3 Series B 73 : X=H, 74: X=CH3, 75 : X=Cl Series C 76: X=H, 77: X=CH3, 78: X=Cl Series D 79: X=H, 80: X=CH3, 81: X=Cl Series E 82: X=H, 83: X=CH3, 84: X=C

N

Scheme 10. Reagents and conditions: (i) nBu4N+Br-, butan-2-one/20% NaOH, 100 C [57]. O NO2

NO2

NH2

HN

O

R S

HN

O

R S O OH

c

OH

OH 87

R

S

N H

N

N

S

N NH

90a-p

bu tio n

88g-90g, R = 1-naphthyl!! 88m-90m, R = methyl 88h-90h, R = quinoline-8-yl!! 88n-90n, R = 3,4-dimethoxyphenyl 88i -90i, R = 5-chlorothiophene-2-yl! 88o-90o, R = 5-(dimethylamino)-1-naphthyl 88j -90j, R = 4-fluorophenyl!! 88p-90p, R = 4-(1,1'-biphenyl) 88k-90k, R = 2,6-dichlorophenyl 88l -90l, R = 4-(trifluoromethyl)phenyl

se

88a-90a, R = phenyl!!! 88b-90b, R = 4-methoxyphenyl!! 88c-90c, R = 4-methylphenyl!! 88d-90d, R = 4-chlorophenyl! ! 88e-90e, R = 3-chloro-4-fluorophenyl! 88f-90f, R = 4-(tert-butyl)phenyl!!

O 89a-p

OH 88a-p

O

O

O

86

e

d

U

85

b

nl y

a

tri

to be the most potent. DMPPQA was synthesized by the procedure described previously [59]. Cytotoxic activity of DMPPQA was tested in human colon cancer cells HCT-116 and umbilical vein endothelial cell line HUVEC. The cytotoxic effect of DMPPQA on the seven cell lines was assessed by MTT assay. DMPPQA was more cytotoxic than the positive control 5fluorouracil (5-FU). DMPPQA inhibits HCT-116 cells proliferation in a time and dose dependent manner by altering mitochondrial respiratory function, inducing apoptosis and increasing ROS production. Moreover, DMPPQA was a potent inhibitor of HUVECs. IC50 values were 100, 16.3 and 7.4 µM in cells treated for 24, 48 and 72 h, respectively. VEGF proteins were significantly reduced by DMPPQA. The scratch assay showed that the DMPPQA significantly inhibited endothelial cell migration in a concentration-dependent manner. DMPPQA also inhibited tube formation, as confirmed by the matrigel tube formation assay. Thus, DMPPQA could act as an angiogenesis inhibitor by decreasing the VEGF protein expression, inhibiting endothelial cell migration and tube formation in HUVEC cells [58].

rD

Pe rs

sequent reduction in the nitro-group of compound (86) by Pd-C/H2 in methanol solution produced compound (87), which was then treated with various substituted sulfonyl chlorides to obtain compounds (88a-p). The oxidation of (88a-p) with NaIO4/SiO2 gave quinone type structures (89a-p). The final products (90a-p) were obtained by the Michael addition reaction [5].

is

on al

Scheme 11. Reagents and conditions: (a) t-BuOOH, KOH, DMSO/H2O (3/1); (b) Pd/C, H2, MeOH; (c) Pyridine, 0°C; (d) NaIO4/SiO2, DCM, rt; (e) DMF, rt [5].

N

ot

Fo

All compounds (90a-p) synthesized were assayed for biological activities. These studies indicated that N(3-((7H-purin-6-yl)thio)-4-hydroxynaphthalen-1yl)sulfonamide exerted enhanced antiproliferative activity against human umbilical vein endothelial cells (HUVECs), several cancer cell lines, high specific protein kinase and angiogenesis inhibitory activities. Among these compounds, (90n) comprehensively showed strong inhibitory effect, and demonstrated comparable in vitro antiangiogenic activities to pazopanib in both HUVEC tube formation assay and the rat thoracic aorta rings (TARs) test. Compound (90n) provided almost complete inhibition of angiogenesis at 5 µM [5].

Ren group [58] presented the synthesis a series of novel 4-aminoquinoline derivatives and assessed their cytotoxic effects on 7 cancer cell lines. Among these compounds the antitumor activity of 5,7-dimethoxy-2phenyl-N-propylquinolin-4-amine (DMPPQA) seemed

Activation of the mammalian target of rapamycin (mTOR) has also been implicated in cancer, metabolic diseases, and aging. Nanoparticles surface-function-



All synthesized compounds were tested for VEGFR-2 kinase activity. Studies indicated that the urea compounds (X = NH) were more activite than the corresponding amides (X = CH2). Compounds (91h, 91n, and 91o) revealed the most potent cytotoxic activity with IC50 values equal to 5.5, 16, and 17 nmol, respectively. Moreover, derivative (91h) exhibited a good kinase selectivity, antiproliferative potency, oral exposure, and efficacy in tumor xenograft models [61]. CONCLUSION

The conducted research has opened new directions for the design and development of new and more potent inhibitors of angiogenesis with promising antitumor activity. During metastasis, angiogenesis caused by cancer plays a key role. The prognosis of cancer is mainly determined by the presence or absence of metastases, it is important for the discovery of new targets of cancer angiogenesis and metastasis. Although there are some limitations, they are effectively used in reducing angiogenesis. To improve the clinical performance, a better understanding of the biology of cancer and underlying angiogenesis and tumor survival is necessary, as well as mechanisms of antiangiogeneic resistance. Finally, in order to improve the results of treatment, it is possible to use a combinatorial approach using antiangiogenic agents, targeted molecular therapy, and immunotherapy or cytotoxics. It is important to choose the drugs individually and do not treat statistically.

bu tio n

tri

rD

Fo

N

ot

Pe rs

Yu et al. [61] synthesized series of 4-anilinoquinazolines derivatives (91a-o) which showed potent, selective inhibition against VEGFR-2 (Fig. 10). The intermediate aromatic ureas (95a-i) were prepared by reaction of arylamines (92a-i) with triphosgene in the presence of triethylamine to obtain the isocyanates (93a-i). Compounds (93a-i) were reacted with aniline derivatives followed by hydrolysis under basic conditions to produce ureas (94a-i). As a result of reduction of (94a-i) in the presence of palladium-charcoal in methanol (95a-i) (Scheme 12) were obtained. The intermediate aromatic amides (98a-c) were prepared starting from carboxylic acid (96) and thionyl chloride to give acyl chloride (97), which by reaction with aniline derivatives produced amides (98a-c). Then, the reduction of the nitro group by Pd/C-catalyzed hydrogenation gave 99a-c (Scheme 13). The compounds (91a-o) were prepared in three steps. As a result of reaction 7-fluoroquinazolone (100) with N-methyl-4piperidinemethanol in the presence of NaH produced the corresponding C-7-piperidine-methanoxyanilinoquinazolines derivatives (101). Following chlo-

is

on al

U

se

O

Loos et al. [60] synthesized the polystyrene nanoparticles with amino groups (PS-NH2) and with carboxyl groups (PS-COOH) by free-radical copolymerization in a direct (oil in water) miniemulsion system. Biological activity of nanoparticles depends on their surface functionalization, which procures contact with the surrounding media. Thus, surface configurations critically determine the interaction of nanomaterials with biological targets such as membranes and individual biomolecules. Polar groups, such as amino or carboxyl groups, modify the cellular uptake of nanoparticles, with carboxyl-functionalized nanoparticles being much more avidly taken up by macrophages than amino-functionalized ones. PS-COOH and PS-NH2 nanoparticles induce autophagy, but only in PS-NH2 treated cells, acidic vesicular organelles show elevated pH and impaired processing of procathepsin B and autophagy, followed by permeabilization of acidic vesicular organelles and induction of apoptosis. Moreover, PS-NH2 inhibits angiogenesis and proliferation of leukemia cells xenografted. It was shown that functionalized nanoparticles can be used to control activation of mTOR signaling pathways, and to influence proliferation and viability of malignant cells [60].

rination of (101) with thionyl chloride afforded 4chloroquinoline (102). Finally, compounds (102) were coupled with (95a-i) or (99a-c) to gave (91a-o) (Scheme 14) [61].

nl y

alized with amino or carboxyl groups might provide a tool to control mTOR activation, which might improve disease management and increase the lifespan [60].

3843

The research has opened new directions in the design and development of new and potent inhibitors of angiogenesis with promising antitumor activity. Drugs that block angiogenesis and anti-angiogenic agents have become an important element in the treatment of many types of cancer. Although in the market there are a number of drugs that inhibit angiogenesis approved by the US Food and Drug Administration, such as: Bawacizumab (Avastin), Everolimus (Afinitor), Pazopanib (Votrient), Sorafenib (Nexavar) or Sunitinib (Sutent), they cause a number of side effects such as: high blood pressure, rash or itchy skin, diarrhea, fatigue, etc. Angiogenesis inhibitors can also cause severe bleeding, heart attack, heart failure or blood clots. Therefore, it is important to look for new and safer drugs for human to block angiogenesis.


Gensicka et al.

R2

H N

X

R3

91d: X=NH, R 1=H, R2=H, R3=

O

HN R1

91a: X=CH2, R1=H, R2=H, R 3=3-CF3-4-Cl-Ph 91b: X=CH2, R 1=H, R2=H, R3=3-F-Ph 91c: X=CH2, R1=H, R 2=H, R3=3-F-4-F-Ph

91e: X=NH, R 1=H, R2=H, R3= N

O

91f: X=NH, R1=H, R 2=H, R3=

N

N

R2

R2 NH2 92a-l

a

O2N

NCO

b

on al

O2N

N H

R3

c

H2N

O N H

N H

R3

95a-l

tri

94a-l

N H

95d: X=NH, R1=H, R2=H, R3=3-CF3-4-Cl-Ph 95e: X=NH, R1=H, R2=H, R3=3-F-Ph 95f: X=NH, R1=H, R2=H, R3=3-F-4-F-Ph 95g: X=NH, R1=H, R2=H, R3=4-CH3-3-Br-Ph 95h: X=NH, R1=H, R2=H, R3=2-F-4-Br-Ph 95i: X=NH, R1=H, R2=F, R3=3-F-Ph 95j: X=NH, R1=H, R2=Cl, R3=3-F-Ph 95k: X=NH, R1=OCH3, R2=H, R3=3-F-Ph 95l: X=NH, R1=OCH3, R2=F, R3=3-F-Ph

95a: R2=H, R3=

rD

Pe rs

93a-l

R2

O

is

O2N

R2

bu tio n

U

Fig. (10). Structures of compounds (91a-o) [61].

se

O

nl y

91g: X=NH, R 1=H, R2=H, R3=3-CF3-4-Cl-Ph 91h: X=NH, R1=H, R 2=H, R3=3-F-Ph 91i: X=NH, R1=H, R 2=H, R3=3-F-4-F-Ph 91j: X=NH, R1=H, R2=H, R 3=4-CH3-3-Br-Ph 91k: X=NH, R1=H, R 2=H, R3=2-F-4-Br-Ph 91l: X=NH, R1=H, R2=F, R 3=3-F-Ph 91m: X=NH, R1=H, R2=Cl, R3=3-F-Ph 91n: X=NH, R1=OCH3, R 2=H, R3=3-F-Ph 91o: X=NH, R 1=OCH3, R2=F, R 3=3-F-Ph

95b: R2=H, R3=

Fo

95c: R2=H, R3=

ot

Scheme 12. Synthesis of aromatic urea compounds (95a-l). Reagents and conditions: (a) triphosgene, CH2Cl2, rt, triethylamine; (b) the corresponding aniline derivative, CH2Cl2, rt,; (c) Pd/C, methanal [61].

N

OH

O2N

O

96

Cl

a O2N

O 97

H N

b O2N

R3

O 98a-c c H N

99a: R3=3-CF3-4-Cl-Ph 99b: R3=3-F-Ph 99c: R3=3-F-4-F-Ph

H2N

R3

O 99a-c

Scheme 13. Synthetic of aromatic amide compounds (99a-c). Reagents and conditions: (a) SOCl2, 60 °C; (b) the corresponding aniline derivative, CH2Cl2, rt, K2CO3; (c) Pd/C, methanal [61].

Inhibitors of Angiogenesis in Cancer Therapy O

O R1

R1 NH

F


O

N

R1 O N

101

d H N

R3

R1

nl y

N

O

N

O

91d-o

R3

O

HN N

O N

H N O

HN R1

H N

N 102

c R2

N

b

N

N

100

Cl NH

a

3845

N N 91a-c

ACKNOWLEDGEMENTS

REFERENCES

[3]

[4]

[5]

[6]

Fo

ot

[2]

[10]

[11] [12]

Benzekry, S.; Gandolfi, A.; Hahnfeldt, P. Global Dormancy of Metastases Due to Systemic Inhibition of Angiogenesis. PLos One, 2014, 9(1), e84249. Chiarella, P.; Bruzzo, J.; Meiss, R.P.; Ruggiero, R.A. Concomitant tumor resistance. Cancer Lett., 2012, 324, 133141. Ranieri, G.; Mammì, M.; Donato Di Paola, E.; Russo, E.; Gallelli, L.; Citraro, R.; Gadaleta, C.D.; Marech, I.; Ammendola, M.; De Sarro, G. Pazopanib a tyrosine kinase inhibitor with strong anti-angiogenetic activity: A new treatment for metastatic soft tissue sarcoma. Crit. Rev. Oncol. Hematol., 2014, 89, 322-329. Vives, M.; Ginestà, M.M.; Gracova, K.; Graupera, M.; Casanovas, O.; Capellà, G.; Serrano, T.; Laquente, B.; Viñals, F. Metronomic chemotherapy following the maximum tolerated dose is an effective anti-tumour therapy affecting angiogenesis, tumour dissemination and cancer stem cells. Int. J. Cancer, 2013, 133, 2464. Xu, F.; Xu, H.; Wang, X.; Zhang, L.; Wen, Q.; Zhang, Y.; Xu, W. Discovery of N-(3-((7H-purin-6-yl)thio)-4hydroxynaphthalen-1-yl)-sulfonamide derivatives as novel protein kinase and angiogenesis inhibitors for the treatment of cancer: Synthesis and biological evaluation. Part III. Bioorg. Med. Chem., 2014, 22, 1487-1495. Jarosz, P.; Woźniak, B. Angiogenesis in cancer diseases. Prz. Med. Univ. Rzesz. Inst. Lek., 2012, 4, 498-507.

N

[1]

[9]

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Pe rs

This work was financially supported by the National Science Center (Poland), grant no 2014/13/B/NZ7/ 02234.

[8]

Battegay, E.J. Angiogenesis mechanistic insights, neovascular diseases. Mol. Med., 1995, 73, 333-346. Carmeliet, P. Mechanisms of angiogenesis and arteriogenesis. Nat. Med., 2000, 63, 89-95. Cox, G.; Jones, J.L.; Walker, R.A.; Steward, W.P.; O'Byrne, K.J. Angiogenesis and non-small cell lung cancer. Lung Cancer, 2000, 27, 81-100. Fox, S.B.; Gasparini, G.; Harris, A.L. Angiogenesis: pathological, prognostic, and growth-factor pathways and their link to trial design and anticancer drugs. Lancet Oncol., 2001, 2(5), 278-290. Giordano, F.J. Angiogenesesis: mechanisms, modulation, and targeted imaging. J. Nucl. Cardiol., 1999, 6, 664-671. Swidzińska, E.; Naumnik, W.; Chyczewska, E. Angiogenesis and neoangiogenesis-the role in lung cancer and other tumors. Pneumonol. Alergol. Pol., 2006, 74, 414-420. McMahon, G. VEGF Receptor signaling in tumor angiogenesis. Oncologist, 2000, 5, 3-10. Auerbach, W.; Auerbach, R. Angiogenesis inhibition: a review. Pharmacol. Ther., 1994, 63, 265-311. Denekamp, J. The tumor microcirculation as a target in cancer therapy: a clearer perspective. Eur. J. Clin. Invest., 1999, 29, 733-736. Kerbel, R.S. Tumor angiogenesis: past, present and the near future. Carcinogenesis, 2000, 21, 505-515. Eliceiri, B.P.; Cheresh, D.A. The role of αv integrins during angiogenesis: insights into potential mechanisms of action and clinical development. J. Clin. Invest., 1999, 103, 12271230. Wagner, A.D.; Thomssen, C.; Haerting, J.; Unverzagt, S. Vascularendothelial-growth-factor (VEGF) targeting therapies for endocrine refractory or resistant metastatic breast cancer. Cochrane Database Syst. Rev., 2012, 7. Dai, B.; Zhang, Y.; Zhan, Y.; Zhang, D.; Wang, N.; He, L. A novel tissue model for angiogenesis: evaluation of inhibitors or promoters in tissue level. Scientific Reports, 2014, 4, 3693. Gerber, H.P.; Ferrara, N. The role of VEGF in normal and neoplastic hematopoiesis. J. Mol. Med., 2003, 81, 20-31.

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The authors confirm that this article content has no conflict of interest.

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CONFLICT OF INTEREST

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Scheme 14. Synthesis of compounds (91a-o). Reagents and conditions: (a) N-methyl-4-piperidinemethanol, NaH, DMF, 80°C; (b) SOCl2, 60°C; (c) the corresponding compound 95a-l, isopropanol, 80°C; (d) the corresponding compound 99a-c, isopropanol, 80°C [61].

[13]

[14] [15] [16] [17]

[18]

[19]

[20]


[25]

[26]

[40]

[41]

[42]

[32]

[33]

[34]

[35] [36]

tri

is

[44]

rD

Fo

ot

[31]

[43]

[45]

[46]

[47]

N

[30]

Pe rs

[29]

on al

U

[27] [28]

[39]

bu tio n

[24]

[38]

nl y

[23]

[37]

lan, J.; Cutillas, R.; Smith, A.J.H.; Ridley, A.J.; Ruhrberg, C.; Gerhardt, H.; Vanhaesebroeck, B. The catalytic subunits of class IA phosphoinositide 3-kinases (PI3K) are activated by distinct signals and have discrete roles in angiogenesis and vascular remodeling. Nature, 2008, 453, 662-666. Zhang, L.; Yang, N.; Katsaros, D.; Huang, W.; Park, J.W.; Fracchioli, S.; Vezzani, C.; Rigault de la Longrais, I.A; Yao, W.; Rubin, S.C.; Coukos, G. The oncogene phosphatidylinositol 3’-kinase catalytic subunit α promotes angiogenesis via vascular endothelial growth factor in ovarian carcinoma. Cancer Res., 2003, 63, 4225-4231. Crowell, J.A.; Steele, V.E.; Fay, J.R. Targeting the AKT protein kinase for cancer chemoprevention. Mol. Cancer Ther., 2007, 6(8), 2139-2148. Jiang B.H.; Liu, L.Z. Role of mTOR in anticancer drug resistance: perspectives for improved drug treatment. Drug Resist. Updat., 2008, 11(3), 63-76. Chen, Y.; Huang, Y.F.; Huang, Y.L.; Xia, X.; Zhang, J.; Zhou, Y.; Tan, Y.; He, S.; Qiang, F.; Li, A.; Re, O.; Li, G.; Zhou, J.; JWA suppresses tumor angiogenesis via Sp1activated matrix metalloproteinase-2 and its prognostic significance in human gastric cancer. Carcinogenesis, 2014, 35(2), 442-451. Kim, O.; Jeong, Y.; Lee, H.; Hong, S.S.; Hong, S. Design and synthesis of imidazopyridine analogues as inhibitors of phosphoinositide 3-kinase signaling and angiogenesis. J. Med. Chem., 2011, 54(7), 2455-2466. Yu, H.S.; Wang, S.W.; Chang, A.C.; Tai, H.C.; Yeh, H.I.; Lin, Y.M.; Tang, C.H. Bradykinin promotes vascular endothelial growth factor expression and increases angiogenesis in human prostate cancer cells. Biochem. Pharmacol., 2014, 87(2), 243-253. Chen, F.; Wang, M.; Bai, J.; Liu, Q.; Xi, Y.; Li, W.; Zheng, J. Role of RUNX3 in suppressing metastasis and angiogenesis of human prostate cancer. PLos One, 2014, 9(1), e86917. Hu, J.; Yan, M.; Pu, C.; Wang, J.; Van der Steen, P.; Opdenakker, G.; Xu, H. Chemically synthesized matrix metalloproteinase and angiogenesis-inhibiting peptides as anticancer agents. Anti-cancer Agents Med. Chem., 2014, 14(3), 483-494. Puxeddu, I.; Rabl, S.; Panza, F.; Pratesi, F.; Rocchi, V.; Del Corso, I.; Migliorini, P. Endostatin and Thrombospondin-1 levels are increased in the sera of patients with chronic spontaneous urticarial. Arch. Dermatol. Res., 2014, 306(2), 197-200. Yan, Y.; Shen, Z.; Ye, Y.; Jiang, K.; Zhang, H.; Shen, C.; Mustonen, H.; Puolakkainen, P.; Wang, S. A novel molecular marker of prognosis in colorectal cancer: Vasohibin-1. Med. Oncol., 2014, 31(2), 816. Reck, M.; Kaiser, R.; Mellemgaard, A.; Douillard, J.Y.; Orlov, S.; Krzakowski, M.; Pawel, J.; Gottfried. M.; Bondarenko, I.; Liao, M.; Gann, C.N.; Barrueco, J.; GaschlerMarkefski, B.; Novello, S. Docetaxel plus nintedanib versus docetaxel plus placebo in patients with previously treated non-small-cell lung cancer (LUME-Lung 1): a phase 3, double blind, randomised trial. Lancet Oncol., 2014, 15, 143-155. Hilberg, F.; Roth, G.J.; Krssak, M.; Kautschitsch, S.; Sommergruber, W.; Tontsch-Grunt, U.; Garin-Chesa, P.; Bader, G.; Zoephel, A.; Quant, J.; Heckel, A.; Rettig, W. BIBF 1120:triple angiokinase inhibitor with sustained receptor blockade and good antitumor efficacy. Cancer Res., 2008, 68, 4774-4782. Scagliotti, G.; Govindan, R. Targeting angiogenesis with multitargeted tyrosine kinase inhibitors in the treatment of non-small cel lung cancer. Oncologist, 2010, 15, 436-446.

O

[22]

Na, H.J.; Hwang, J.Y.; Lee, K.S.; Choi, Y.K.; Choe, J.; Kim, J.Y.; Moon, H.E.; Kim, K.W.; Koh, G.Y.; Lee, H.; Jeoung, D.; Won, M.H.; Ha, K.S.; Kwon, Y.G.; Kim, Y.M. TRAIL negatively regulates VEGF-induced angiogenesis via caspase-8-mediated enzymatic and non-enzymatic functions. Springer, 2014, 17(1), 179-194. Ferrara, N. Role of vascular endothelial growth factor in the regulation of angiogenesis. Kidney Int., 1999, 56(3), 794814. Prasadam, I.; Zhiu, Y.; Du, Z.; Chen, J.; Crawford, R.; Xiao, Y. Osteocyte-induced angiogenesis via VEGFMAPK-dependent pathways in endothelial cells. Mol. Cell. Biochem., 2014, 386, 15-25. Grosicki, S.; Grosicka, A.; Hołowiecki, J. Clinical importance of angiogenesis and angiogenic factors in oncohematology. Wiad. Lek., 2007, 60(1-2), 39-46. Verda, L.; Luo, K., Han, X.; Wasserstrom, A.; Lomasney, J.; Kowalska, B.; Burt, R.K. Effect of G-CSF and intramyocardial injection of bone marrow cells on cardiac function in mouse model of myocardial infarction: a word for neovasculogenesis. Blood, 2004, 11(104), 2693-2693. Murakami, H. New pharmacological availability of thalidomide based on the experiences in patients with multiple myeloma. Nihon Hansenbyo Gakkai Zasshi, 2004, 73(3), 235-244. http://www.chemspider.com/ Thomeas, V.; Chow, S.; Gutierrez, J.O.; Karovic, S.; Wroblewski, K.; Kistner-Griffin, E.; Karrison, T.G.; Maitland, M.L. Technical considerations in the development of circulating peptides as pharmacodynamic biomarkers for angiogenesis inhibitors. J. Clin. Pharmacol., 2014, 54, 682687. Young, R.; Woll, P.; Staton, C.; Reed, M.; Brown, N. Vascular-targeted agents for the treatment of angiosarcoma, cancer chemotherapy and pharmacology. Cancer Chemother. Pharmacol., 2014, 73(2), 259-270. Albiges, L.; Oudard, S.; Negrier, S,.; Caty, A.; Gravis, G.; Joly, F.; Duclos, B.; Geoffrois, L.; Rolland, F.; Guillot, A.; Laguerre, B.; Legouffe, E.; Kohser, F.; Dietrich, P.Y.; Theodore, C.A.; Escudier, B. Complete remission with tyrosine kinase inhibitors in renal cell carcinoma. J. Clin. Oncol., 2012, 30, 482-7. Johannsen, M.; Staehler, M.; Ohlmann, C.H.; Flörcken, A.; Schmittel, A.; Otto, T.; Bex, A.; Hein, P.; Miller, K.; Weikert, S.; Grünwald, V. Outcome of treatment discontinuation in patients with metastatic renal cell carcinoma and no evidence of disease following targeted therapy with or without metastasectomy. Ann. Oncol., 2011, 22, 657-63. Iacovelli, R.; Alesini, D.; Palazzo, A.; Trenta, P.; Santoni, M.; De Marchis, L.; Cascinu, S.; Naso, G.; Cortesi, E. Targeted therapies and complete responses in first line treatment of metastatic renal cell carcinoma. A meta-analysis of published trials. Cancer Treat. Rev., 2014, 40, 271-275. Celik, F.; Ulas, F.; Ozunal, Z.; Firat, T.; Celebi, S.; Dogan, U. Comparison of the effect of intravitreal bevacizumab and intravitreal fasudil on retinal VEGF, TNFα, and caspase 3 levels in an experimental diabetes model. Int. J. Ophthalmol., 2014, 7(1), 57-61. Kawada, I.; Hasina, R.; Arif, Q.; Mueller, J.; Smithberger, E.; Husain, A.N.; Vokes, E.E.; Salgia, R. Dramatic antitumor effects of the dual MET/RON small-molecule inhibitor LY2801653 in non-small cell lung cancer. Cancer Res., 2014, 74, 884-895. Krześlak, A. Akt kinase: a key regulator of metabolism and progression of tumors. Post. Hig. Med. Dosw., 2010, 64, 490-503. Graupera, M.; Guillermet-Guibert, J.; Foukas, C.; Phng, L.K.; Cain, R.J.; Salpekar, A.; Pearce, W.; Meek, S.; Mil-

se

[21]

Gensicka et al.

[48]

[49]



[50]

novel VEGFR-2 inhibitors: Design, synthesis and biological evaluation. Bioorg. Med. Chem., 2014, 22(1), 277-284. Lebedyeva, I.O.; Ostrov, D.A.; Neubert, J.; Steel, P.J.; Sileno, S.M., Goncalves, K.; Ibrahim, M.A.; Almary, K.A.; Katritzky, A.R. Gabapentin hybrid peptides and bioconjugates. Bioorg. Med. Chem., 2014, 22, 1479-1486. Ravez, S.; Barczyk, A.; Six, P.; Cagnon, A.; Garofalo, A.; Goossens, L.; Depreux, P. Inhibition of tumor cell growth and angiogenesis by 7-aminoalkoxy-4-aryloxy-quinazoline ureas, a novel series of multi-tyrosine kinase inhibitors. Eur. J. Med. Chem., 2014, 79, 369-381. Ren, J.; Jiang, H.; Zhao, J.; Xin, W.; Xu, Y.; Chen, X.; Hu, K. DMPPQA, a novel angiogenesis inhibitor, induces apoptosis in human colon cancer HCT-116 cells and HUVECs. Cell Biol. Int., 2014, 38, 343-354. Ren, J.; Zhao, J.; Zhao, Y.S.; Liu, X.H.; Chen, X.; Hu, K. Synthesis and antitumor activity of novel 4-aminoquinoline derivatives. Med. Chem. Res., 2012, 22, 2855-2861. Loos, C.; Syrovets, T.; Musyanovych, A.; Mailänder, V.; Landfester, K.; Simmet, T. Amino-functionalized nanoparticles as inhibitors of mTOR and inducers of cell cycle arrest in leukemia cells. Biomaterials, 2014, 35, 1944-1953. Yu, B.; Tang, L.; Li, Y.; Song, S.; Ji, X.; Lin, M.; Wu, C. Design, synthesis and antitumor activity of 4aminoquinazoline derivatives targeting VEGFR-2 tyrosine kinase. Bioorg. Med. Chem. Lett., 2012, 22, 110-114.

[54]

[59] [60]

[61]

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N

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Pe rs

tri

Accepted: August 31, 2015

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Revised: August 27, 2015

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Received: March 16, 2015

U

se

[55]

[58]

bu tio n

[53]

[57]

nl y

[52]

[56]

O

[51]

Kutluk Cenik, B.; Ostapoff, K.T.; Gerber, D.E.; Brekken, R.A. BIBF 1120 (nintedanib), a triple angiokinase inhibitor, induces hypoxia but not EMT and blocks progression of preclinical models of lung and pancreatic cancer. Mol. Cancer Ther., 2013, 12(6), 992-1001. Hanna, N.H.; Kaiser, R.; Sullivan, R.N.; Aren, O.R.; Ahn, M.J.; Tiangco, B.; Zvirbule, Z.; Barrios, C.H.; Demirkazik, A.; Gaschler-Markefski, B.; Voccia, I.; Barrueco, J.; Kim, J.H.; Simon, M.; Simon, B. Lume-lung 2: A multicenter, randomized, double-blind, phase III study of nintedanib plus pemetrexed versus placebo plus prmetrexed in patients with failure of first-line chemotherapy. Proc. Am. Soc. Clin. Oncol., 2013, 31, 8034. Mansfield, A.; Markovic, S. Inhibition of angiogenesis for the treatment of metastatic melanoma. Curr. Oncol. Rep., 2013, 15(5), 492-499. Elice, F.; Rodeghiero, F. Side effects of anti-angiogenic drugs. Thromb Res., 2012, 129, S50-S53. Shahzad, S.A.; Yar, M.; Bajda, M.; Jadoon, B.; Khan, Z.A.; Naqvi, S.A.; Shaikh, A.J.; Hayat, K., Mahmmod, A.; Mahmmod, N.; Filipek, S. Synthesis and biological evaluation of novel oxadiazole derivatives: A new class of thymidine phosphorylase inhibitors as potential anti-tumor agents. Bioorg. Med. Chem., 2014, 22(3), 1008-1015. Wang, C.; Gao, H.; Dong, J.; Zhang, Y.; Su, P.; Shi, Y.; Zhang, J. Biphenyl derivatives incorporating urea unit as

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