Ramucirumab in combination with pembrolizumab for recurrent or metastatic head and neck squamous cell carcinoma: a single-centre, phase 1/2 trial.

BACKGROUND: VEGF, a key mediator of angiogenesis and resistance to immunotherapy, is overexpressed in head and neck squamous cell carcinoma (HNSCC). We aimed to determine the recommended phase 2 dose of ramucirumab, a selective VEGFR2 inhibitor, given with pembrolizumab and the objective response rate of this combination as first-line treatment for recurrent or metastatic HNSCC. METHODS: In this single-centre, phase 1/2 trial, which was done at Washington University (St Louis, MO, USA), eligible patients were aged 18 years or older with incurable recurrent or metastatic HNSCC and an Eastern Cooperative Oncology Group performance status of 0-2. Patients in phase 2 were required to have had no previous systemic therapy for recurrent or metastatic disease. In a dose de-escalation phase 1 design, patients received ramucirumab (starting dose 10 mg/kg given intravenously) and pembrolizumab (200 mg intravenously) on day 1 of each 21-day cycle. The recommended phase 2 dose of ramucirumab was defined as the highest dose at which one or fewer of three patients had dose-limiting toxicity during cycle one (primary endpoint of phase 1). In a Simon's two-stage phase 2 design, patients received the recommended phase 2 dose of ramucirumab and pembrolizumab. Tumour response (primary endpoint of phase 2) was assessed by Response Evaluation Criteria in Solid Tumours (version 1.1). We hypothesised that there would be an objective response rate of 32% or higher (null ≤13%). Eight or more responses among 33 evaluable patients (those with at least one response assessment) was evidence for activity (80% power; one-sided α=0·05). Analyses were done per protocol. The trial is registered with ClinicalTrials.gov, NCT03650764, and is closed to enrolment. FINDINGS: Between June 18, 2019, and Feb 11, 2021, three patients enrolled and were treated in phase 1 and 37 patients in phase 2. Median age of all patients was 64 years (IQR 59-72). 36 (90%) of 40 patients were men and four (10%) were women, and 36 (90%) patients were White, three (8%) were Black or African American, and one (3%) was Asian. In phase 1, no dose-limiting toxicity event occurred. The recommended phase 2 dose of ramucirumab was 10 mg/kg. Median follow-up for patients on phase 2 was 14·8 months (IQR 4·9-31·0). In phase 2, 18 (55%; 95% CI 38-70) of 33 evaluable patients had an objective response, including confirmed complete response in 11 patients, confirmed partial response in six patients, and unconfirmed partial response in one patient. The most common grade 3 or worse adverse events were dysphagia (14 [38%] of 37 patients), lung infection (11 [30%]), lymphocyte count decrease (ten [27%]), hypophosphataemia (nine [24%]), and hypertension (eight [22%]). No treatment-related deaths were recorded. INTERPRETATION: Ramucirumab and pembrolizumab were safe to administer to patients with recurrent or metastatic HNSCC, and the objective response rate with this combination as first-line treatment for recurrent or metastatic HNSCC was favourable. Further studies of ramucirumab and pembrolizumab in patients with recurrent or metastatic HNSCC are warranted. FUNDING: Lilly and the Joseph Sanchez Foundation.

ALK5/VEGFR2 dual inhibitor TU2218 alone or in combination with immune checkpoint inhibitors enhances immune-mediated antitumor effects.

Transforming growth factor ß (TGFß) is present in blood of patients who do not respond to anti-programmed cell death (ligand) 1 [PD-(L)1] treatment, and through synergy with vascular endothelial growth factor (VEGF), it helps to create an environment that promotes tumor immune evasion and immune tolerance. Therefore, simultaneous inhibition of TGFß/VEGF is more effective than targeting TGFß alone. In this study, the dual inhibitory mechanism of TU2218 was identified through in vitro analysis mimicking the tumor microenvironment, and its antitumor effects were analyzed using mouse syngeneic tumor models. TU2218 directly restored the activity of damaged cytotoxic T lymphocytes (CTLs) and natural killer cells inhibited by TGFß and suppressed the activity and viability of regulatory T cells. The inactivation of endothelial cells induced by VEGF stimulation was completely ameliorated by TU2218, an effect not observed with vactosertib, which inhibits only TGFß signaling. The combination of TU2218 and anti-PD1 therapy had a significantly greater antitumor effect than either drug alone in the poorly immunogenic B16F10 syngeneic tumor model. The mechanism of tumor reduction was confirmed by flow cytometry, which showed upregulated VCAM-1 expression in vascular cells and increased influx of CD8 + CTLs into the tumor. As another strategy, combination of anti-CTLA4 therapy and TU2218 resulted in high complete regression (CR) rates in CT26 and WEHI-164 tumor models. In particular, immunological memory generated by the combination of anti-CTLA4 and TU2218 in the CT26 model prevented the development of tumors after additional tumor cell transplantation, suggesting that the TU2218-based combination has therapeutic potential in immunotherapy.

Magnetic resonance imaging-based approaches for detecting the efficacy of combining therapy following VEGFR-2 and PD-1 blockade in a colon cancer model.

BACKGROUND: Angiogenesis inhibitors have been identified to improve the efficacy of immunotherapy in recent studies. However, the delayed therapeutic effect of immunotherapy poses challenges in treatment planning. Therefore, this study aims to explore the potential of non-invasive imaging techniques, specifically intravoxel-incoherent-motion diffusion-weighted imaging (IVIM-DWI) and blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI), in detecting the anti-tumor response to the combination therapy involving immune checkpoint blockade therapy and anti-angiogenesis therapy in a tumor-bearing animal model. METHODS: The C57BL/6 mice were implanted with murine MC-38 cells to establish colon cancer xenograft model, and randomly divided into the control group, anti-PD-1 therapy group, and combination therapy group (VEGFR-2 inhibitor combined with anti-PD-1 antibody treatment). All mice were imaged before and, on the 3rd, 6th, 9th, and 12th day after administration, and pathological examinations were conducted at the same time points. RESULTS: The combination therapy group effectively suppressed tumor growth, exhibiting a significantly higher tumor inhibition rate of 69.96% compared to the anti-PD-1 group (56.71%). The f value and D* value of IVIM-DWI exhibit advantages in reflecting tumor angiogenesis. The D* value showed the highest correlation with CD31 (r = 0.702, P = 0.001), and the f value demonstrated the closest correlation with vessel maturity (r = 0.693, P = 0.001). While the BOLD-MRI parameter, R2* value, shows the highest correlation with Hif-1α(r = 0.778, P < 0.001), indicating the capability of BOLD-MRI to evaluate tumor hypoxia. In addition, the D value of IVIM-DWI is closely related to tumor cell proliferation, apoptosis, and infiltration of lymphocytes. The D value was highly correlated with Ki-67 (r = - 0.792, P < 0.001), TUNEL (r = 0.910, P < 0.001) and CD8a (r = 0.918, P < 0.001). CONCLUSIONS: The combination of VEGFR-2 inhibitors with PD-1 immunotherapy shows a synergistic anti-tumor effect on the mouse colon cancer model. IVIM-DWI and BOLD-MRI are expected to be used as non-invasive approaches to provide imaging-based evidence for tumor response detection and efficacy evaluation.

Targeting EGFR and VEGFR-2 Kinases With Nanoparticles: A Computational Approach for Cancer Therapy Advancement.

The study investigates titanium and zinc nanoparticles as inhibitors for the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor-2 (VEGFR-2), pivotal regulators of cell processes. VEGFR-2 activation fuels tumor angiogenesis in cancer cells, sustaining malignant tissue expansion. Molecular docking analysis illustrates the nanoparticles' binding to the active sites, inhibiting the phosphorylation of key proteins in downstream signaling. This inhibition offers a promising therapeutic approach to impede cancer-related signaling, potentially slowing down aberrant protein cascades controlled by EGFR and VEGFR-2. The findings propose a novel avenue for cancer treatment, targeting abnormal growth pathways using titanium and zinc nanoparticles.

Iodoquinazoline-derived VEGFR-2 and EGFRT790M dual inhibitors: Design, synthesis, molecular docking and anticancer evaluations.

Herein, we report the synthesis of a series of new fourteen iodoquinazoline derivatives 7a-c to 13a-e and their evaluation as potential anticancer agents via dual targeting of EGFRT790M and VEGFR-2. The new derivatives were designed according to the target receptors structural requirements. The compounds were evaluated for their cytotoxicity against HepG2, MCF-7, HCT116 and A549 cancer cell lines using MTT assay. Compound 13e showed the highest anticancer activities with IC50 = 5.70, 7.15, 5.76 and 6.50 µM against HepG2, MCF-7, HCT116 and A549 cell lines correspondingly. Compounds 7c, 9b and 13a-d exhibited very good anticancer effects against the tested cancer cell lines. The highly effective six derivatives 7c, 10, 13b, 13c, 13d and 13e were examined against VERO normal cell lines to estimate their cytotoxic capabilities. Our conclusion revealed that compounds 7c, 10, 13b, 13c, 13d and 13e possessed low toxicity against VERO normal cells with IC50 prolonging from 41.66 to 53.99 µM. Also compounds 7a-c to 13a-e were further evaluated for their inhibitory activity against EGFRT790M and VEGFR-2. Also, their ability to bind with both EGFR and VEGFR-2 receptors was examined by molecular modeling. Compounds 13e, 13d, 7c and 13c excellently inhibited VEGFR-2 activity with IC50 = 0.90, 1.00, 1.25 and 1.50 µM respectively. Moreover, Compounds 13e, 7c, 10 and 13d excellently inhibited EGFRT790M activity with IC50 = 0.30, 0.35, 0.45 and 0.47 µM respectively. Finally, our derivatives 7b, 13d and 13e showed good in silico calculated ADMET profile.

Challenging the anticolorectal cancer capacity of quinoxaline-based scaffold via triazole ligation unveiled new efficient dual VEGFR-2/MAO-B inhibitors.

Monoamine oxidases (MAOs) and vascular endothelial growth factor receptor-2 (VEGFR-2) are promoters of colorectal cancer (CRC) and central signaling nodes in epithelial-mesenchymal transition (EMT) induced by activating hypoxia-inducible factors (HIFs). Herein, a novel series of rationally designed triazole-tethered quinoxalines were synthesized and evaluated against HCT-116 CRC cells. The tailored scaffolds combine the pharmacophoric themes of both VEGFR-2 inhibitors and MAO inhibitors. All the synthesized derivatives were screened utilizing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay for their possible cytotoxic effects on normal human colonocytes, then evaluated for their anticancer activities against HCT-116 cells overexpressing MAOs. The hit derivatives 11 and 14 exhibited IC50 = 18.04 and 7.850 µM, respectively, against HCT-116cells within their EC100 doses on normal human colonocytes. Wound healing assay revealed their efficient CRC antimetastatic activities recording HCT-116 cell migration inhibition exceeding 75 %. In vitro enzymatic assays demonstrated that both 11 and 14 efficiently inhibited VEGFR-2 (IC50 = 88.79 and 9.910 nM), MAO-A (IC50 = 0.763 and 629.1 nM) and MAO-B (IC50 = 0.488 and 209.6 nM) with observed MAO-B over MAO-A selectivity (SI = 1.546 and 3.001), respectively. Enzyme kinetics studies were performed for both compounds to identify their mode of MAO-B inhibition. Furthermore, qRT-PCR analysis showed that the hits efficiently downregulated HIF-1α in HCT-116cells by 3.420 and 16.96 folds relative to untreated cells. Docking studies simulated their possible binding modes within the active sites of VEGFR-2 and MAO-B to highlight their essential structural determinants of activities. Finally, they recorded in silico drug-like absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiles as well as ligand efficiency metrics.

Discovery of novel pyrazole based Urea/Thiourea derivatives as multiple targeting VEGFR-2, EGFRWT, EGFRT790M tyrosine kinases and COX-2 Inhibitors, with anti-cancer and anti-inflammatory activities.

A novel series of pyrazole derivatives with urea/thiourea scaffolds 16a-l as hybrid sorafenib/erlotinib/celecoxib analogs was designed, synthesized and tested for its VEGFR-2, EGFRWT, EGFRT790M tyrosine kinases and COX-2, pro-inflammatory cytokines TNF-α and IL-6 inhibitory activities. All the tested compounds showed excellent COX-2 selectivity index in range of 18.04-47.87 compared to celecoxib (S.I. = 26.17) and TNF-α and IL-6 inhibitory activities (IC50 = 5.0-7.50, 6.23-8.93 respectively, compared to celecoxib IC50 = 8.40 and 8.50, respectively). Screening was carried out against 60 human cancer cell lines by National Cancer Institute (NCI), compounds 16a, 16c, 16d and 16 g were the most potent inhibitors with GI% ranges of 100 %, 99.63-87.02 %, 98.98-43.10 % and 98.68-23.62 % respectively, and with GI50 values of 1.76-15.50 µM, 1.60-5.38 µM, 1.68-7.39 µM and 1.81-11.0 µM respectively, in addition, of showing good safety profile against normal cell line (F180). Moreover, compounds 16a, 16c, 16d and 16 g had cell cycle arrest at G2/M phase with induced necrotic percentage compared to sorafenib of 2.06 %, 2.47 %, 1.57 %, 0.88 % and 1.83 % respectively. Amusingly, compounds 16a, 16c, 16d and 16 g inhibited VEGFR-2 with IC50 of 25 nM, 52 nM, 324 nM and 110 nM respectively, compared to sorafenib (IC50 = 85 nM), and had excellent EGFRWT and EGFRT790M kinase inhibitory activities (IC50 = 94 nM, 128 nM, 160 nM, 297 nM), (10 nM, 25 nM, 36 nM and 48 nM) respectively, compared to both erlotinib and osimertinib (IC50 = 114 nM, 56 nM) and (70 nM, 37 nM) respectively and showed (EGFRwt/EGFRT790M S.I.) of (range: 4.44-9.40) compared to erlotinib (2.03) and osmertinib (1.89).

Discovery of novel thiophene-3-carboxamide derivatives as potential VEGFR-2 inhibitors with anti-angiogenic properties.

VEGFR-2 is an attractive target for the development of anti-tumor drugs and plays a crucial role in tumor angiogenesis. This study reports a series of novel thiophene-3-carboxamide derivatives based on PAN-90806 as VEGFR-2 inhibitors, among which compound 14d exhibits excellent anti-proliferative activity against HCT116, MCF7, PC3, and A549 cell lines, and has effective VEGFR-2 inhibitory activity with an IC50 value of 191.1 nM. Additionally, CETSA results indicated that VEGFR-2 was a relevant target of compound 14d in the cell lines, and compound 14d could also inhibit VEGFR-2 protein phosphorylation in A549 cell line. Furthermore, compound 14d inhibited colony formation, cell migration, and HUVECs tube formation in a dose-dependent manner. The mechanism by which 14d induced cancer cell death involves blocking the cell cycle, increasing ROS production, inducing apoptosis, and dose-dependently reducing the levels of phosphorylated ERK and MEK. Molecular docking and molecular dynamics simulations had shown that compound 14d could stably bind to the active site of VEGFR-2. These results confirmed that compound 14d might be a promising lead compound for anti-angiogenesis.

Design, synthesis, and ex vivo anti-drug resistant cervical cancer activity of novel molecularly targeted chalcone derivatives.

Chemotherapy toxicity and tumor multidrug resistance remain the main reasons for clinical treatment failure in cervical cancer. In this study, 79 novel chalcone derivatives were designed and synthesized using the principle of active substructure splicing with the parent nucleus of licorice chalcone as the lead compound and VEGFR-2 and P-gp as the target of action and their potentials for anticervical cancer activity were preliminarily evaluated. The results showed that the IC50 values of candidate compound B20 against HeLa and HeLa/DDP cells were 3.66 ± 0.10 and 4.35 ± 0.21 µΜ, respectively, with a resistance index (RI) of 1.18, which was significantly higher than that of the positive drug cisplatin (IC50:13.60 ± 1.63, 100.03 ± 7.94 µΜ, RI:7.36). In addition, B20 showed significant inhibitory activity against VEGFR-2 kinase and P-gp-mediated rhodamine 123 efflux, as well as the ability to inhibit the phosphorylation of VEGFR-2 and downstream PI3K/AKT signaling pathway proteins, inducing apoptosis, blocking cells in the S-phase, and inhibiting invasive migration and tubule generation by HUVEC cells. Acceptable safety was demonstrated in acute toxicity tests when B20 was at 200 mg/kg. In the nude mouse HeLa/DDP cell xenograft tumor model, the inhibition rate of transplanted tumors was 39.2 % and 79.2 % when B20 was at 10 and 20 mg/kg, respectively. These results suggest that B20 is a potent VEGFR-2 and P-gp inhibitor with active potential for treating cisplatin-resistant cervical cancer.

Utility of sulfachloropyridazine in the synthesis of novel anticancer agents as antiangiogenic and apoptotic inducers.

In a search for new anticancer agents with better activity and selectivity, the present work described the synthesis of several new series of sulfachloropyridazine hybrids with thiocarbamates 3a-e, thioureids 4a-h, 5a-e and 4-substituted sulfachloropyridazines 6a, b, 7a, b and 8. The synthesized compounds were screened in vitro against a panel of 60 cancer cell lines in one dose assay. The most potent derivatives 3a, 3c, 4c, 4d, 5e, 7a and 7b were tested for their antiangiogenic activity by measuring their ability to inhibit VEGFR-2. The most potent compounds in VEGFR-2 inhibitory assay were further evaluated for their ability to inhibit PDGFR. In addition, the ability of 4c compound to inhibit cell migration on HUVEC cells and cell cycle effect on UO-31 cells has been studied. The pro-apoptotic effect of compound 4c was studied by the evaluation of caspase-3, Bax and BCl-2. Alternatively, the IC50 of compounds 3a, 3c, 4c, 5e, 7a and 7b against certain human cancer cell lines were determined. Re-evaluation in combination with γ-radiation was carried out for compounds 4c, 5e and 7b to study the possible synergistic effect on cytotoxicity. Docking studies of the most active compounds were performed to give insights into the binding mode within VEGFR-2 active site.

Novel quinazolin-2-yl 1,2,3-triazole hybrids as promising multi-target anticancer agents: Design, synthesis, and molecular docking study.

In our study, a series of quinazoline-1,2,3-triazole hybrids (14a-r) have been designed and synthesized as multi-target EGFR, VEGFR-2, and Topo II inhibitors. All synthesized hybrids were assessed for their anticancer capacity. MTT assay revealed that compounds 14a, 14d, and 14k were the most potent hybrids against four cancer cell lines, HeLa, HePG-2, MCF-7, and HCT-116 at low micromolar range while exhibiting good selectivity against normal cell line WI-38. Sequentially, the three compounds were evaluated for EGFR, VEGFR-2, and Topo II inhibition. Compound 14d was moderate EGFR inhibitor (IC50 0.103 µM) compared to Erlotinib (IC50 0.049 µM), good VEGFR-2 inhibitor (IC50 0.069 µM) compared to Sorafenib (IC50 0.031 µM), and stronger Topo II inhibitor (IC50 19.74 µM) compared to Etoposide (IC50 34.19 µM) by about 1.7 folds. Compounds 14k and 14a represented strong inhibitory activity against Topo II with (IC50 31.02 µM and 56.3 µM) respectively, compared to Etoposide. Additionally, cell cycle analysis and apoptotic induction were performed. Compound 14d arrested the cell cycle on HeLa at G2/M phase by 17.53 % and enhanced apoptosis by 44.08 %. A molecular Docking study was implemented on the three hybrids and showed proper binding interaction with EGFR, VEGFR-2, and Topo II active sites.

Design, synthesis and cytotoxic evaluation of new thieno[2,3-d]pyrimidine analogues as VEGFR-2/AKT dual inhibitors, apoptosis and autophagy inducers.

Novel thieno[2,3-d]pyrimidine analogues were designed, synthesized and evaluated for anti-proliferative activity against HepG-2, PC-3 and MCF-7 cancer cell lines. In addition, WI-38 normal cell line was used to explore the safety of all the tested compounds. Compounds 2 (IC50 = 4.29 µM HePG-2, 10.84 µM MCF-7), 6 (IC50 = 14.86 µM HePG-2, 8.04 µM PC-3 and 12.90 µM MCF-7) and 17 (IC50 = 9.98 µM HePG-2, 33.66 µM PC-3 and 14.62 µM MCF-7) were the most promising candidates on the tested cancer cells with high selective toxicity-sparing normal cells. A further mechanistic evaluation revealed promising kinase inhibitory activity, where compound 2 inhibited VEGFR-2 and AKT at IC50 = 0.161 and 1.06 µM, respectively, Furthermore, derivative 6 inhibited VEGFR-2 and AKT at IC50 = 0.487 and 0.364 µM, respectively, while compound 17 showed IC50 = 0.164 and 0.452 µM, respectively. Moreover, compounds 2, 6 resulted in G1 phase cell cycle arrest while candidate 17 arrest cell cycle at G2/M phase. Similar to the apoptosis results, compound 17 showed the highest autophagic induction among the evaluated derivatives. Finally, docking studies were conducted to assess the binding patterns of these active derivatives. The results showed that the binding patterns inside the active sites of both the VEGFR-2 and AKT-1 (allosteric pocket) crystal structures were identical to the reference ligands.

Novel NO-TZDs and trimethoxychalcone-based DHPMs: design, synthesis, and biological evaluation as potential VEGFR-2 inhibitors.

Novel series of nitric oxide-releasing thiazolidine-2,4-diones (NO-TZD-3a-d,5,6) and 3,4,5-trimethoxychalcone-based multifunctional 1,4-dihydropyrimidines (CDHPM-10a-g) have been designed and synthesised as potent broad-spectrum anticancer agents with potential VEGFR-2 inhibition. The designed analogs were evaluated for their anticancer activities towards a full panel of NCI-60 tumour cell lines and CDHPM-10a-g emerged mean %inhibitions ranging from 76.40 to 147.69%. Among them, CDHPM-10e and CDHPM-10f demonstrated the highest MGI% of 147.69 and 140.24%, respectively. Compounds CDHPM-10a,b,d-f showed higher mean %inhibitory activity than the reference drug sorafenib (MGI% = 105.46%). Superiorly, the hybrid CDHPM-10e displayed the highest potencies towards all the herein tested subpanels of nine types of cancer with MGI50 of 1.83 µM. Also, it revealed potent cytostatic single-digit micromolar activity towards the herein examined cancer cell lines. The designed compounds CDHPM-10a-g were exposed as potent non-selective broad-spectrum anticancer agents over all NCI subpanels with an SI range of 0.66-1.97. In addition, the target analog CDHPM-10e revealed potency towards VEGFR-2 kinase comparable to that of sorafenib with a sub-micromolar IC50 value of 0.11 µM. Also, CDHPM-10e could effectively induce Sub-G1-phase arrest and prompt apoptosis via caspase and p53-dependent mechanisms. Furthermore, CDHPM-10e revealed significant anti-metastatic activity as detected by wound healing assay. The modelling study implies that CDHPM-10e overlaid well with sorafenib and formed a strong H-bond in the DFG binding domain. The ADMET studies hinted out that CDHPM-10e met Pfizer's drug-likeness criteria. The presented novel potent anticancer agent merits further devotion as a new lead product in developing more chalcone-based VEGFR-2 inhibitors.

Heparin-binding VEGFR1 variants as long-acting VEGF inhibitors for treatment of intraocular neovascular disorders.

Neovascularization is a key feature of ischemic retinal diseases and the wet form of age-related macular degeneration (AMD), all leading causes of severe vision loss. Vascular endothelial growth factor (VEGF) inhibitors have transformed the treatment of these disorders. Millions of patients have been treated with these drugs worldwide. However, in real-life clinical settings, many patients do not experience the same degree of benefit observed in clinical trials, in part because they receive fewer anti-VEGF injections. Therefore, there is an urgent need to discover and identify novel long-acting VEGF inhibitors. We hypothesized that binding to heparan-sulfate proteoglycans (HSPG) in the vitreous, and possibly other ocular structures, may be a strategy to promote intraocular retention, ultimately leading to a reduced burden of intravitreal injections. We designed a series of VEGF receptor 1 variants and identified some with strong heparin-binding characteristics and ability to bind to vitreous matrix. Our data indicate that some of our variants have longer duration and greater efficacy in animal models of intraocular neovascularization than current standard of care. Our study represents a systematic attempt to exploit the functional diversity associated with heparin affinity of a VEGF receptor.

New benzimidazole-oxadiazole derivatives as potent VEGFR-2 inhibitors: Synthesis, anticancer evaluation, and docking study.

We report herein, the design and synthesis of benzimidazole-oxadiazole derivatives as new inhibitors for vascular endothelial growth factor receptor-2 (VEGFR-2). The designed members were assessed for their in vitro anticancer activity against three cancer cell lines and two normal cell lines; A549, MCF-7, PANC-1, hTERT-HPNE and CCD-19Lu. Compounds 4c and 4d were found to be the most effective compounds against three cancer cell lines. Compounds 4c and 4d were then tested for their in vitro VEGFR-2 inhibitory activity, safety profiles, and selectivity indices using the normal hTERT-HPNE and CCD-19Lu cell lines. It was determined that compound 4c was the most effective and safe member of the produced chemical family. Vascular endothelial growth factor A (VEGFA) immunolocalizations of compounds 4c and 4d were evaluated relative to control by VEGFA immunofluorescence staining. Compounds 4c and 4d inhibited VEGFR-2 enzyme with half-maximal inhibitory concentration values of 0.475 ± 0.021 and 0.618 ± 0.028 µM, respectively. Molecular docking of the target compounds was carried out in the active site of VEGFR-2 (Protein Data Bank: 4ASD).

Variations of VEGFR2 Chemical Space: Stimulator and Inhibitory Peptides.

The kinase pathway plays a crucial role in blood vessel function. Particular attention is paid to VEGFR type 2 angiogenesis and vascular morphogenesis as the tyrosine kinase pathway is preferentially activated. In silico studies were performed on several peptides that affect VEGFR2 in both stimulating and inhibitory ways. This investigation aims to examine the molecular properties of VEGFR2, a molecule primarily involved in the processes of vasculogenesis and angiogenesis. These relationships were defined by the interactions between Vascular Endothelial Growth Factor receptor 2 (VEGFR2) and the structural features of the systems. The chemical space of the inhibitory peptides and stimulators was described using topological and energetic properties. Furthermore, chimeric models of stimulating and inhibitory proteins (for VEGFR2) were computed using the protein system structures. The interaction between the chimeric proteins and VEGFR was computed. The chemical space was further characterized using complex manifolds and high-dimensional data visualization. The results show that a slightly similar chemical area is shared by VEGFR2 and stimulating and inhibitory proteins. On the other hand, the stimulator peptides and the inhibitors have distinct chemical spaces.

In Vivo, In Vitro and In Silico Anticancer Activity of Ilama Leaves: An Edible and Medicinal Plant in Mexico.

Ilama leaves are an important source of secondary metabolites with promising anticancer properties. Cancer is a disease that affects a great number of people worldwide. This work aimed to investigate the in vivo, in vitro and in silico anticancer properties of three acyclic terpenoids (geranylgeraniol, phytol and farnesyl acetate) isolated from petroleum ether extract of ilama leaves. Their cytotoxic activity against U-937 cells was assessed using flow cytometry to determine the type of cell death and production of reactive oxygen species (ROS). Also, a morphological analysis of the lymph nodes and a molecular docking study using three proteins related with cancer as targets, namely, Bcl-2, Mcl-1 and VEGFR-2, were performed. The flow cytometry and histomorphological analysis revealed that geranylgeraniol, phytol and farnesyl acetate induced the death of U-937 cells by late apoptosis and necrosis. Geranylgeraniol and phytol induced a significant increase in ROS production. The molecular docking studies showed that geranylgeraniol had more affinity for Bcl-2 and VEGFR-2. In the case of farnesyl acetate, it showed the best affinity for Mcl-1. This study provides information that supports the anticancer potential of geranylgeraniol, phytol and farnesyl acetate as compounds for the treatment of cancer, particularly with the potential to treat non-Hodgkin's lymphoma.

Identification of Benzothiazoles Bearing 1,3,4-Thiadiazole as Antiproliferative Hybrids Targeting VEGFR-2 and BRAF Kinase: Design, Synthesis, BIO Evaluation and In Silico Study.

Cancer remains a leading cause of death worldwide, often resulting from uncontrolled growth in various organs. Protein kinase inhibitors represent an important class of targeted cancer therapies. Recently, the kinases BRAF and VEGFR-2 have shown synergistic effects on tumor progression. Seeking to develop dual BRAF/VEGFR-2 inhibitors, we synthesized 18 amino-benzothiazole derivatives with structural similarities to reported dual inhibitors. Four compounds-4a, 4f, 4l, and 4r-demonstrated remarkable cytotoxicity, with IC50 values ranging from 3.58 to 15.36 µM, against three cancer cell lines. Furthermore, these compounds showed IC50 values of 38.77-66.22 µM in the case of a normal cell line, which was significantly safer than the reference, sorafenib. Subsequent investigation revealed that compound 4f exhibited the capacity to inhibit the BRAF and VEGFR-2 enzymes, with IC50 values similar to sorafenib (0.071 and 0.194 µM, respectively). Moreover, compound 4f caused G2-M- and S-phase cycle arrest. Molecular modeling demonstrated binding patterns compatible with inhibition for both targets, where 4f exerted the critical interactions in the BRAF site and interacted in the VEGFR-2 site in a manner akin to sorafenib, demonstrating affinity similar to dabrafenib.

Discovery of VEGFR inhibitors through virtual screening and energy assessment.

Vascular endothelial growth factor receptor-2 (VEGFR-2) is crucial in promoting tumor angiogenesis and cancer metastasis. Thus, inhibition of VEGFR-2 has appeared as a good tactic for cancer treatment. To find out novel VEGFR-2 inhibitors, first, the PDB structure of VEGFR-2, 6GQO, was selected based on atomic nonlocal environment assessment (ANOLEA) and PROCHECK assessment. 6GQO was then further used for structure-based virtual screening (SBVS) of different molecular databases, including US-FDA approved drugs, US-FDA withdrawn drugs, may bridge, MDPI, and Specs databases using Glide. Based on SBVS, receptor fit, drug-like filters, and absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis of 427877 compounds, the best 22 hits were selected. From the 22 hits, hit 5 complex with 6GQO was put through molecular mechanics/generalized born surface area (MM/GBSA) study and hERG binding. The MM/GBSA study revealed that hit 5 possesses lesser binding free energy with more inferior stability in the receptor pocket than the reference compound. The VEGFR-2 inhibition assay of hit 5 disclosed an IC50 of 165.23 nM against VEGFR-2, which can be possibly enhanced through structural modifications.

Inhibition of VEGFR-2 by SU5416 increases neonatally glutamate-induced neuronal damage in the cerebral motor cortex and hippocampus.

Vascular endothelial growth factor (VEGF) exerts neuroprotective or proinflammatory effects, depending on what VEGF forms (A-E), receptor types (VEGFR1-3), and intracellular signaling pathways are involved. Neonatal monosodium glutamate (MSG) treatment triggers neuronal death by excitotoxicity, which is commonly involved in different neurological disorders, including neurodegenerative diseases. This study was designed to evaluate the effects of VEGFR-2 inhibition on neuronal damage triggered by excitotoxicity in the cerebral motor cortex (CMC) and hippocampus (Hp) after neonatal MSG treatment. MSG was administered at a dose of 4 g/kg of body weight (b.w.) subcutaneously on postnatal days (PD) 1, 3, 5, and 7, whereas the VEGFR-2 inhibitor SU5416 was administered at a dose of 10 mg/kg b.w. subcutaneously on PD 5 and 7, 30 min before the MSG treatment. Neuronal damage was assessed using hematoxylin and eosin staining, fluoro-Jade staining, and TUNEL assay. Additionally, western blot assays for some proteins of the VEGF-A/VEGFR-2 signaling pathway (VEGF-A, VEGFR-2, PI3K, Akt, and iNOS) were carried out. All assays were performed on PD 6, 8, 10, and 14. Inhibition of VEGFR-2 signaling by SU5416 increases the neuronal damage induced by neonatal MSG treatment in both the CMC and Hp. Moreover, neonatal MSG treatment increased the expression levels of the studied VEGF-A/VEGFR-2 signaling pathway proteins, particularly in the CMC. We conclude that VEGF-A/VEGFR-2 signaling pathway activation could be part of the neuroprotective mechanisms that attempt to compensate for neuronal damage induced by neonatal MSG treatment and possibly also in other conditions involving excitotoxicity.