New nicotinamide derivatives as potential anticancer agents targeting VEGFR-2: design, synthesis, in vitro, and in silico studies

Herin, new nicotinamide candidates were designed and synthesized as VEGFR-2 inhibitors. In vitro antiproliferative activities were assessed against MCF-7, HepG-2 and HCT-116 cancer cell lines. The top cytotoxic members 15a, 15b, 16, 18a, and 18b were estimated against their selected target (VEGFR-2). Further mechanistic tests were studied for the most potent cytotoxic candidate 18a, these studies revealed the ability of compound 18a to hinder the progression of HCT-116 cells at S and Pre-G1phases besides boosting early and late apoptosis. Also compound 18a was found to significantly decrease the levels immunomodulatory proteins TNF-α and IL-6 while showing a four-fold rise in an apoptotic marker caspase-3 when compared to control cells. The therapeutic index of the designed derivatives was evaluated by computational ADMET and toxicity calculations as well as their potentiality to occupy the VEGFR-2 active site was signposted by molecular docking assessments. Finally, molecular dynamic simulation studies of compound 18a-VEGFR-2 complex indicated the high steadiness of compound 18a in the VEGFR-2 active site. This study presents compound 18a as a lead candidate that can be optimized to get a strong VEGFR-2 inhibitor.Communicated by Ramaswamy H. Sarma.

Biomechanical stimulation promotes blood vessel growth despite VEGFR-2 inhibition

BACKGROUND

Angiogenesis, or the growth of new vasculature from existing blood vessels, is widely considered a primary hallmark of cancer progression. When a tumor is small, diffusion is sufficient to receive essential nutrients; however, as the tumor grows, a vascular supply is needed to deliver oxygen and nutrients into the increasing mass. Several anti-angiogenic cancer therapies target VEGF and the receptor VEGFR-2, which are major promoters of blood vessel development. Unfortunately, many of these cancer treatments fail to completely stop angiogenesis in the tumor microenvironment (TME). Since these therapies focus on the biochemical activation of VEGFR-2 via VEGF ligand binding, we propose that mechanical cues, particularly those found in the TME, may be a source of VEGFR-2 activation that promotes growth of blood vessel networks even in the presence of VEGF and VEGFR-2 inhibitors.

RESULTS

In this paper, we analyzed phosphorylation patterns of VEGFR-2, particularly at Y1054/Y1059 and Y1214, stimulated via either VEGF or biomechanical stimulation in the form of tensile strains. Our results show prolonged and enhanced activation at both Y1054/Y1059 and Y1214 residues when endothelial cells were stimulated with strain, VEGF, or a combination of both. We also analyzed Src expression, which is downstream of VEGFR-2 and can be activated through strain or the presence of VEGF. Finally, we used fibrin gels and microfluidic devices as 3D microtissue models to simulate the TME. We determined that regions of mechanical strain promoted increased vessel growth, even with VEGFR-2 inhibition through SU5416.

CONCLUSIONS

Overall, understanding both the effects that biomechanical and biochemical stimuli have on VEGFR-2 activation and angiogenesis is an important factor in developing effective anti-angiogenic therapies. This paper shows that VEGFR-2 can be mechanically activated through strain, which likely contributes to increased angiogenesis in the TME. These proof-of-concept studies show that small molecular inhibitors of VEGFR-2 do not fully prevent angiogenesis in 3D TME models when mechanical strains are introduced.

Exploring the anticancer properties of a new nicotinamide analogue: Investigations into in silico analysis, antiproliferative effects, selectivity, VEGFR-2 inhibition, apoptosis induction, and migration suppression

BACKGROUND

This study focuses on the development and evaluation of (E)-N-(3-(1-(2-(4-bromobenzoyl)hydrazono)ethyl)phenyl)nicotinamide (BHEPN) as a potential inhibitor of Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2).

METHODS

Computational investigations as density function theory (DFT), docking, molecular dynamics (MD) simulations, and ADMET) in addition to in vitro (VEGFR-2 inhibition, cytotoxicity against HepG2 and MCF-7 cancer cell lines, selectivity index, cells cycle analysis, apoptosis investigation, and cells migration assay) studies were conducted.

RESULTS

DFT calculations determined the three-dimensional structure and indicated the reactivity of BHEPN. Molecular docking, and MD simulations analysis showed the BHEPN's binding affinity and its potential as a VEGFR-2 inhibitor. ADMET assessments predicted BHEPN's safety and drug-like characteristics. In vitro investigations confirmed the inhibition of VEGFR-2 with an IC50 value of 0.320 ± 0.012 µM. BHEPN also exhibited remarkable cytotoxic effects against HepG2 and MCF-7 cancer cell lines, with IC50 values of 0.19 ± 0.01 µM and 1.18 ± 0.01 µM, respectively, outperforming Sorafenib's IC50 values (2.24 ± 0.06 µM and 3.17 ± 0.01 µM), respectively. Notably, BHEPN displayed a higher IC50 value of 4.11 ± 0 µM against the non-carcinogenic Vero cell lines, indicating selectivity index values of 21.6 and 3.4 against the tested cancer cell lines, respectively. In a flow cytometry assay, BHEPN induced HepG2 cell cycle arrest at the G1/S phase. Moreover, BHEPN increased the incidence of early and late apoptosis in HepG2 cell lines (from 1.38% and 0.22%) in control cells to (4.11-26.02%) in the treated cells, respectively. Additionally, the percentage of necrosis raised to 13.39%, in contrast to 0.62% in control cells. Finally, BHEPN was able to reduce the migration and wound healing abilities in HepG2 cells to 38.89% compared to 87.92% in untreated cells after 48 h. These in vitro results aligned with the computational predictions, providing strong evidence of BHEPN's efficacy and safety in anticancer applications.

CONCLUSIONS

BHEPN is a promising candidate for the development of novel anticancer agents through further in vitro and in vivo investigations.

Does cabergoline administration affect endometrial VEGFR-2 expression in a rat model of ovarian hyperstimulation syndrome?

OBJECTIVE

To assess the effect of cabergoline on endometrial vascular endothelial growth factor receptor-2 (VEGFR-2) immunoexpression in an ovarian hyperstimulation syndrome (OHSS) rat model.

MATERIAL AND METHODS

Twenty-one immature female Wistar rats were assigned into three groups: group 1, the control group; group 2, stimulated with gonadotropins to mimic OHSS; and group 3, in which an OHSS protocol was induced and thereafter treated with cabergoline (100 μg/kg/day). Body weight, ovarian volume, corpora lutea numbers, and endometrial VEGFR-2 expression were compared between the groups.

RESULTS

Weight gain and ovarian volume were highest in the OHSS-placebo group, while cabergoline administration significantly reversed those effects (p = 0.001 and p = 0.001, respectively). VEGFR-2 stained cells were significantly lower in groups 2 and 3 compared to group 1 (p = 0.002). Although VEGFR-2 expression was lowest in group 3, the difference was not statistically significant. Corpora lutea numbers were also similar (p = 0.465).

CONCLUSION

While successful implantation requires a vascularized receptive endometrium, impaired expression of VEGFR-2 and disrupted endometrial angiogenesis due to cabergoline administration may be associated with IVF failure in fresh OHSS cycles. The insignificant decrease in endometrial VEGFR-2 expression observed in this research needs to be investigated by further studies involving additional techniques such as immunoblotting and/or RT-PCR analyses.

Identification of new benzimidazole-triazole hybrids as anticancer agents: multi-target recognition, in vitro and in silico studies

Multi-target inhibitors represent useful anticancer agents with superior therapeutic attributes. Here in, two novel series of benzimidazole-triazole hybrids were designed, synthesised as multi-target EGFR, VEGFR-2 and Topo II inhibitors, and evaluated for anticancer activity. Compounds 5a and 6g were the most potent analogues against four cancer cell lines, HepG-2, HCT-116, MCF-7 and HeLa, and were further evaluated for EGFR, VEGFR-2, and Topo II inhibition. Compound 5a was especially good inhibitor for EGFR (IC₅₀ = 0.086 µM) compared to Gefitinib (IC₅₀ = 0.052 µM), moderate VEGFR-2 inhibitor (IC₅₀ = 0.107 µM) compared to Sorafenib (IC₅₀ = 0.0482 µM), and stronger Topo II inhibitor (IC₅₀ = 2.52 µM) than Doxorubicin (IC₅₀ = 3.62 µM). Compound 6g exhibited moderate EGFR and VEGFR-2 inhibition and weaker Topo II inhibition. DNA binding assay, cell cycle analysis, apoptotic induction, molecular docking, and physicochemical studies were additionally implemented to explore the plausible mechanism of the active compounds.

Design and biological evaluation of 3-substituted quinazoline-2,4(1H,3H)-dione derivatives as dual c-Met/VEGFR-2-TK inhibitors

The dual c-Met/vascular endothelial growth factor receptor 2 (VEGFR-2) TK inhibition is a good strategy to overcome therapeutic resistance to small molecules VEGFR-2 inhibitors. In this study, we designed 3-substituted quinazoline-2,4(1H,3H)-dione derivatives as dual c-Met/VEGFR-2 TK inhibitors. We introduced new synthetic methods for reported derivatives of 3-substituted quinazoline-2,4(1H,3H)-dione 2a-g, in addition to the preparation of some new derivatives namely, 3 and 4a-j. Three compounds namely, 2c, 4b, and 4e showed substantial amount of inhibition for both c-Met and VEGFR-2 TK (IC₅₀ range 0.052-0.084 µM). Both compounds 4b, 4e showed HB with highly conserved residue Asp1222 in the HB region of c-Met TK. For VEGFR-2 TK, compound 4b showed HB with a highly conserved residue Asp1046 in the HB region. Compound 4e showed HB with Glu885 and Asp1046. Moreover, in silico prediction of pharmacokinetic and physicochemical parameters of target compounds was carried out using SwissADME website. The quinazoline-2,4(1H,3H)-dione derivatives are promising antiproliferative candidates that require further optimisation.HighlightsNew 3-substituted quinazoline-2,4(1H,3H)-dione derivatives were synthesised and characterised.Compounds 4b and 4e showed higher cytotoxic activity than cabozantinib against HCT-116 colorectal cell lines.Both compounds 4b and 4e showed less toxicity to WI38 normal cell line compared to HCT 116 colon cancer cell line.Compound 4b was superior to cabozantinib in VEGFR-2 inhibition while compound 2c was equipotent to cabozantinib.Compounds 4b and 4e showed remarkable c-Met inhibitory activity.Compounds 4b and 4e arrested cell cycle and induced significant levels of apoptosis.In silico ADME prediction revealed high oral bioavailability and enhanced water solubility of target compounds as compared to cabozantinib.Target compounds interacted with both c-Met and VEGFR-2 active site in similar way to cabozantinib.

Synthesis of novel nicotinic acid derivatives of potential antioxidant and anticancer activity

This study comprises the design and synthesis of novel nicotinic acid-based cytotoxic agents with selective inhibitory efficacy against the vascular endothelial growth factor receptor-2 (VEGFR-2). Screening of novel compounds for cytotoxicity was assessed against 60 human cancer cell lines. The two most active compounds, 5b and 5c, and the reference drugs sorafenib and doxorubicin were investigated against HCT-15, PC-3, and CF-295 cancer cell lines. Compound 5c exhibited the highest cytotoxic potential compared to doxorubicin against the HCT-15 and PC-3 tumor cell lines. Moreover, it exhibited higher cytotoxic potential and selectivity toward the HCT-15 cell panel compared with sorafenib. Compound 5c demonstrated promising VEGFR-2 inhibition (concentration needed to inhibit cell viability by 50%, IC50  = 0.068 μM) and superior VEGFR-2 selectivity over the epidermal growth factor receptor and platelet-derived growth factor receptor-β enzymes. It also reduced the total and phosphorylated VEGFR-2 and induced apoptosis, as evidenced by a 4.3-fold rise in caspase-3 levels. The antioxidant potential of the new compounds was determined via measuring the superoxide dismutase (SOD) levels, among which compound 5c exhibited an SOD level almost comparable to ascorbic acid. These results suggested that compound 5c exhibited dual cytotoxic and antioxidant activities. Docking of 5c into the VEGFR-2 pocket showed a similar binding mode to sorafenib. Moreover, the ADME (absorption, distribution, metabolism, and excretion) profile of 5c outlined drug-likeness. Finally, The density functional theory calculations displayed an increased binding affinity of 5c to the target enzyme.

New thiazolidine-2,4-diones as effective anti-proliferative and anti-VEGFR-2 agents: Design, synthesis, in vitro, docking, MD simulations, DFT, ADMET, and toxicity studies

Novel thiazolidine-2,4-dione derivatives, 11a-g, were designed, and synthesized targeting the VEGFR-2 protein. The in vitro studies indicated the abilities of the synthesized derivatives to inhibit VEGFR-2 and prevent the growth of two different cancer cell types, HepG2 and MCF-7. Compound 11 f exhibited the strongest anti-VEGFR-2 activity (IC50 = 0.053 µM). As well, compound 11 f showed impressive anti-proliferative activity against the mentioned cancer cell lines with IC50 values of 0.64 ± 0.01 and 0.53 ± 0.04 µM, respectively. Additionally, compound 11 f arrested the MCF-7 cell cycle at the S phase and increased the overall apoptosis percentage. Furthermore, cell migration assay revealed that compound 11 f has a significant ability to prevent migration and healing potentialities of MCF-7. Moreover, computational studies were used to conduct the molecular investigation of the VEGFR-2-11 f complex. The kinetic and structural features of the complex were examined using molecular dynamics simulations and molecular docking. Besides, Principal component analysis (PCA) was used to explain the dynamics of the VEGFR-2-11 f complex at various spatial scales. The DFT calculations also provided further clarity regarding compound 11 f's structural and electronic features. To evaluate how closely the developed compounds might look like drugs, ADMET and toxicity experiments were computed. To conclude, the presented study demonstrates the potential of compound 11 f as a viable anti-cancer drug, which can serve as a prototype for future structural modifications and further biological investigations.

Design, semi-synthesis, anti-cancer assessment, docking, MD simulation, and DFT studies of novel theobromine-based derivatives as VEGFR-2 inhibitors and apoptosis inducers

A group of theobromine derivatives was designed based on the key pharmacophoric characteristics of VEGFR-2 inhibitors. HepG2 and MCF-7 cancer cell lines were used to test the obtained compounds for their in vitro anti-proliferative activities. Compound 15 (2-(3,7-Dimethyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)-N-(4-(1-(2-(4-hydroxybenzoyl)hydrazono)ethyl) phenyl)acetamide) was the most potent cytotoxic member against MCF-7 (IC50 = 0.42 µM) and HepG2 (IC50 = 0.22 µM). The effectiveness of VEGFR-2 inhibition was assessed for compound 15, and its IC50 value was calculated to be 0.067 µM. Additional cellular mechanistic investigations showed that compound 15 dramatically increased the population of apoptotic HepG2 cells in both early and late apoptosis. The investigation of apoptotic markers confirmed that compound 15 upregulated the levels of BAX (2.26-fold) and downregulated the levels of Bcl-2 (4.4-fold). The molecular docking investigations, MM-GPSA, PLIP studies, and MD simulations validated the potential of compound 15 to be a VEGFR-2 inhibitor. DFT calculations have been completed to comprehend how the electrical charge is distributed within compound 15 and to predict how it would bond to VEGFR-2. Lastly, ADMET prediction showed that the designed members have drug-like characteristics and minimal levels of toxicity. In conclusion, our in vitro and in silico investigations showed that compound 15 exhibited promising apoptotic anticancer potential through the suppression of VEGFR-2.

Novel N-Arylmethyl-aniline/chalcone hybrids as potential VEGFR inhibitors: synthesis, biological evaluations, and molecular dynamic simulations

Significant advancements have been made in the domain of targeted anticancer therapy for the management of malignancies in recent times. VEGFR-2 is characterised by its pivotal involvement in angiogenesis and subsequent mechanisms that promote tumour cells survival. Herein, novel N-arylmethyl-aniline/chalcone hybrids 5a-5n were designed and synthesised as potential anticancer and VEGFR-2 inhibitors. The anticancer activity was evaluated at the NCI-USA, resulting in the identification of 10 remarkably potent molecules 5a-5j that were further subjected to the five-dose assays. Thereafter, they were explored for their VEGFR-2 inhibitory activity where 5e and 5h emerged as the most potent inhibitors. 5e and 5h induced apoptosis with cell cycle arrest at the SubG0-G1 phase within HCT-116 cells. Moreover, their impact on some key apoptotic genes was assessed, suggesting caspase-dependent apoptosis. Furthermore, molecular docking and molecular dynamics simulations were conducted to explore the binding modes and stability of the protein-ligand complexes.

Aryl azoles based scaffolds for disrupting tumor microenvironment

Thirty-nine aryl azoles, thirteen triazoles and twenty-seven tetrazoles, have been synthetized and biologically evaluated to determine their activity as tumor microenvironment disruptors. Antiproliferative studies have been performed on tumor cell lines HT-29, A-549 and MCF-7 and on non-tumor cell line HEK-293. It has been studied in HT-29 the expression levels of biological targets which are involved in tumor microenvironment processes, such as PD-L1, CD-47, c-Myc and VEGFR-2. In addition, antiproliferative activity was evaluated when HT-29 were co-cultured with THP-1 monocytes and the secretion levels of IL-6 were also determined in these co-cultures. The angiogenesis effect of some selected compounds on HMEC-1 was also evaluated as well as their action against vasculogenic mimicry on HEK-293. Compounds bearing an amino group in the phenyl ring and a halogen atom in the benzyl ring showed promising results as tumor microenvironment disrupting agents. The most outstanding compound decrease dramatically the population of HT-29 cells when co-cultured with THP-1 monocytes and the levels of IL-6 secreted, as well as it showed moderate effects over PD-L1, CD-47 and c-Myc.

BR55 Ultrasound Molecular Imaging of Clear Cell Renal Cell Carcinoma Reflects Tumor Vascular Expression of VEGFR-2 in a Patient-Derived Xenograft Model

Standard imaging cannot reliably predict the nature of renal tumors. Among malignant renal tumors, clear cell renal cell carcinoma (ccRCC) is the most common histological subtype, in which the vascular endothelial growth factor 2 (VEGFR-2) is highly expressed in the vascular endothelium. BR55, a contrast agent for ultrasound imaging, consists of gas-core lipid microbubbles that specifically target and bind to the extracellular portion of the VEGFR-2. The specific information provided by ultrasound molecular imaging (USMI) using BR55 was compared with the vascular tumor expression of the VEGFR-2 by immunohistochemical (IHC) staining in a preclinical model of ccRCC. Patients' ccRCCs were orthotopically grafted onto Nod-Scid-Gamma (NSG) mice to generate patient-derived xenografts (PdX). Mice were divided into four groups to receive either vehicle or axitinib an amount of 2, 7.5 or 15 mg/kg twice daily. Perfusion parameters and the BR55 ultrasound contrast signal on PdX renal tumors were analyzed at D0, D1, D3, D7 and D11, and compared with IHC staining for the VEGFR-2 and CD34. Significant Pearson correlation coefficients were observed between the area under the curve (AUC) and the CD34 (0.84, p < 10-4), and between the VEGFR-2-specific signal obtained by USMI and IHC (0.72, p < 10-4). USMI with BR55 could provide instant, quantitative information on tumor VEGFR-2 expression to characterize renal masses non-invasively.

Quinazoline-based VEGFR-2 inhibitors as potential anti-angiogenic agents: A contemporary perspective of SAR and molecular docking studies

Angiogenesis, the formation of new blood vessels from the existing vasculature, is pivotal in the migration, growth, and differentiation of endothelial cells in normal physiological conditions. In various types of tumour microenvironments, dysregulated angiogenesis plays a crucial role in supplying oxygen and nutrients to cancerous cells, leading to tumour size growth. VEGFR-2 tyrosine kinase has been extensively studied as a critical regulator of angiogenesis; thus, inhibition of VEGFR-2 has been widely used for cancer treatments in recent years. Quinazoline nucleus is a privileged and versatile scaffold with a broad range of pharmacological activity, especially in the field of tyrosine kinase inhibitors with more than twenty small molecule inhibitors approved by the US Food and Drug Administration in the last two decades. As of now, the U.S. FDA has approved eleven small chemical inhibitors of VEGFR-2 for various types of malignancies, with a prime example being vandetanib, a quinazoline derivative, which is a multi targeted kinase inhibitor used for the treatment of late-stage medullary thyroid cancer. Despite of prosperous discovery and development of VEGFR-2 down regulator drugs, there still exists limitations in clinical efficacy, adverse effects, a high rate of clinical discontinuation and drug resistance. Therefore, there is an urgent need for the design and synthesis of more selective and effective inhibitors to tackle these challenges. Through the gathering of this review, we have strived to broaden the extent of our view over the entire scope of quinazoline-based VEGFR-2 inhibitors. Herein, we give an overview of the importance and advancement status of reported structures, highlighting the SAR, biological evaluations and their binding modes.

Adverse effect of VEGFR-2 (rs1870377) polymorphism on the clinical course of COVID-19 in females and males in an age-dependent manner

The COVID-19 pandemic has affected people worldwide with varying clinical presentations ranging from mild to severe or fatal, and studies have found that age, gender, and some comorbidities can influence the severity of the disease. It would be valuable to have genetic markers that might help predict the likely outcome of infection. For this objective, genes encoding VEGFR-2 (rs1870377), CCR5Δ32 (rs333), and TLR3 (rs5743313) were analyzed for polymorphisms in the peripheral blood of 160 COVID-19 patients before COVID-19 vaccine was available in Türkiye. We observed that possession of the VEGFR-2 rs1870377 mutant allele increased the risk of severe/moderate disease in females and subjects ≥65 years of age, but was protective in males <65 years of age. Other significant results were that the CCR5Δ32 allele was protective against severe disease in subjects ≥65 years of age, while TLR3 rs5743313 polymorphism was found to be protective against severe/moderate illness in males <65 years of age. The VEGFR-2 rs1870377 mutant allele was a risk factor for severe/moderate disease, particularly in females over the age of 65. These findings suggest that genetic polymorphisms have an age- and sex-dependent influence on the severity of COVID-19, and the VEGFR-2 rs1870377 mutant allele could be a potential predictor of disease severity.

Discovery of new VEGFR-2 inhibitors and apoptosis inducer-based thieno[2,3-d]pyrimidine

Background: VEGFR-2 is a key regulator of cancer cell proliferation, migration and angiogenesis. Aim: Development of thieno[2,3-d]pyrimidine derivatives as potential anti-cancer agents targeting VEGFR-2. Methods: Seven in vitro and nine in silico studies were conducted. Results: Compound 10d demonstrated strong anticancer potential, boosting apoptosis based on VEGFR-2 inhibition. It arrested the S phase of the cell cycle and upregulated the apoptotic factors. Docking and molecular dynamics simulation studies confirm the stability of the VEGFR-2-10d complex and suggest that these compounds have good binding affinities to VEGFR-2. In addition, the drug-likeness was confirmed. Conclusion: Thieno[2,3-d]pyrimidines, particularly compound 10d, has good anticancer effects and may contribute to the development of new anticancer therapies.

A Theobromine Derivative with Anticancer Properties Targeting VEGFR-2: Semisynthesis, in silico and in vitro Studies

A computer-assisted drug design (CADD) approach was utilized to design a new acetamido-N-(para-fluorophenyl)benzamide) derivative of the naturally occurring alkaloid, theobromine, (T-1-APFPB), following the pharmacophoric features of VEGFR-2 inhibitors. The stability and reactivity of T-1-AFPB were assessed through density functional theory (DFT) calculations. Molecular docking assessments showed T-1-AFPB's potential to bind with and inhibit VEGFR-2. The precise binding of T-1-AFPB against VEGFR-2 with optimal energy was further confirmed through several molecular dynamics (MD) simulations, PLIP, MM-GBSA, and PCA studies. Then, T-1-AFPB (4-(2-(3,7-Dimethyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)acetamido)-N-(4-fluorophenyl)benzamide) was semi-synthesized and the in vitro assays showed its potential to inhibit VEGFR-2 with an IC50 value of 69 nM (sorafenib's IC50 was 56 nM) and to inhibit the growth of HepG2 and MCF-7 cancer cell lines with IC50 values of 2.24±0.02 and 3.26±0.02 μM, respectively. Moreover, T-1-AFPB displayed very high selectivity indices against normal Vero cell lines. Furthermore, T-1-AFPB induced early (from 0.72 to 19.12) and late (from 0.13 to 6.37) apoptosis in HepG2 cell lines. In conclusion, the combined computational and experimental approaches demonstrated the efficacy and safety of T-1-APFPB providing it as a promising lead VEGFR-2 inhibitor for further development aiming at cancer therapy.

Mechanism of the HIF-1α/VEGF/VEGFR-2 pathway in the proliferation and apoptosis of human haemangioma endothelial cells

Haemangiomas (HAs) are prevalent vascular endothelial cell tumours. With respect to the possible involvement of HIF-1α in HAs, we have explored its role in haemangioma endothelial cell (HemEC) proliferation and apoptosis. shRNA HIF-1α and pcDNA3.1 HIF-α were manipulated into HemECs. HIF-α, VEGF, and VEGFR-2 mRNA and protein levels were assessed by qRT-PCR and Western blotting. Cell proliferation and viability, cell cycle and apoptosis, migration and invasion, and ability to form tubular structures were assessed by colony formation assay, CCK-8, flow cytometry, Transwell assay, and tube formation assay. Cell cycle-related protein levels, and VEGF and VEGFR-2 protein interaction were detected by Western blot and immunoprecipitation assays. An Haemangioma nude mouse model was established by subcutaneous injection of HemECs. Ki67 expression was determined by immunohistochemical staining. HIF-1α silencing suppressed HemEC neoplastic behaviour and promoted apoptosis. HIF-1α facilitated VEGF/VEGFR-2 expression and the VEGF had interacted with VEGFR-2 at protein - protein level. HIF-1α silencing arrested HemECs at G0/G1 phase, diminished Cyclin D1 protein level, and elevated p53 protein level. VEGF overexpression partially abrogated the effects of HIF-1α knockdown on inhibiting HemEC malignant behaviours. Inhibiting HIF-1α in nude mice with HAs repressed tumour growth and Ki67-positive cells. Briefly, HIF-1α regulated HemEC cell cycle through VEGF/VEGFR-2, thus promoting cell proliferation and inhibiting apoptosis.

Novel quinoxaline-based VEGFR-2 inhibitors to halt angiogenesis

Vascular endothelial growth factor receptor-2 is a dynamic target for therapeutic intervention in various types of cancer. This study was aimed at exploring the VEGFR-2 inhibitory activity of a novel library of quinoxalin-2-one derivatives such as 3-furoquinoxaline carboxamides, 3-pyrazolylquinoxalines, and 3-pyridopyrimidyl-quinoxalines. Among them, 6c, 7a, and 7d-f produced remarkable cytotoxicity against HCT-116 (IC50's 4.28-9.31 µM) and MCF-7 (IC50's 3.57-7.57 µM) cell lines using the MTT assay and doxorubicin (DOX) as a reference standard. Interestingly, results of cytotoxicity towards the human fibroblast cell line WI38 revealed that these hits demonstrated higher selectivity indices towards both HCT-116 (SI 8.69-23.19) and MCF-7 (SI 9.48-27.80) than DOX, SI 0.72 and 0.90, respectively. Then, these hits were subjected to a mechanistic study; they showed direct inhibition of VEGFR-2. Impressively, compound 7f displayed 1.2 times the VEGFR-2 inhibitory activity of sorafenib. The antiangiogenic potential of 7f was proved via lowering the level of VEGF-A, than that of control. It as well, exhibited scratch closure percent of 61.8%, compared with 74.5% of control at 48 hrs, indicating the potential anti-migratory effect of the compound 7f. It significantly increased the expression of tumor suppressor gene (p53) on MCF-7 cells by almost 18 folds and upregulated the caspase-3 level by 10.7 folds, compared to the control. Cell cycle analysis revealed cell cycle arrest at G2/M together with a PreG increase which indicated apoptosis induction potential. Annexin V-FITC apoptosis results proposed the two modes of cell death (apoptosis and necrosis) as an inherent mechanism of cytotoxicity of compound 7f. Molecular docking further supported the mechanism showing the affinity of target compounds for VEGFR-2 active site. Moreover, physicochemical and drug-like properties were assessed from the ADME properties.

In vitro and in silico evaluation of new thieno[2,3-d]pyrimidines as anti-cancer agents and apoptosis inducers targeting VEGFR-2

In this study, new thieno[2,3-d]pyrimidine derivatives that could have potential anticancer activity by inhibiting the VEGFR-2 receptor have been designed, synthesized, and investigated. The thieno[2,3-d]pyrimidine derivatives showed strong in vitro abilities to inhibit VEGFR-2 and to prevent cancer cell growth in two different types of cancer cells, MCF-7 and HepG2. Particularly, compound 22 showed the most potent anti-VEGFR-2 activity with an IC50 value of 0.58 µM. Additionally, compound 22 exhibited good anti-proliferative activity against both MCF-7 and HepG2 cancer cell lines, with IC50 values of 11.32 ± 0.32 and 16.66 ± 1.22 µM, respectively. Further investigations revealed that compound 22 induced cell cycle arrest at the G2/M phase and promoted both early and late apoptosis in the MCF-7 cancer cells. Compound 22 also increased the level of BAX (2.8-fold), and reduced the level of Bcl-2 (2.2-fold), hence increasing the rate of apoptosis. Compound 22 also revealed 2.9-fold and 2.8-fold higher levels of caspase-8 and caspase-9, respectively, in the treated MCF-7 cancer cells compared to the control cell lines. The MD simulations showed that the VEGFR-2-22 complex was structurally and energytically stable over 100 ns, while the MM-GBSA study indicated its stable thermodynamic behavior. The bi-dimensional projection analysis confirmed the proper binding of the VEGFR-2-22 complex, while the DFT studies provided optimized geometry, charge distribution, FMO, ESP, the total density of state, and QTAIM maps of compound 22. Finally, computational ADMET studies were performed to assess the drug development potential of the thieno[2,3-d]pyrimidine derivatives. Overall, this study suggests that compound 22 has the potential as an anticancer lead compound by inhibiting VEGFR-2, which may be a guide for future drug design and development.

Novel VEGFR-2 inhibitors as antiangiogenic and apoptotic agents via paracrine and autocrine cascades: Design, synthesis, and biological evaluation

Appertaining to its paracrine and autocrine signaling loops, VEGFR-2 succeeded in grabbing attention as one of the leading targets in cancer treatment. Based on the foregoing and our comprehensive studies regarding pharmacophoric features and activity of sorafenib, novel phenylpyridazinone based VEGFR-2 inhibitors 4, 6a-e, 7a,b, 9a,b, 12a-c, 13a,b, 14a,b, 15a,b, and 17a-d were optimized. An assortment of biological assays was conducted to assess the antiangiogenic and apoptotic activities of the synthesized derivatives. In vitro VEGFR-2 kinase assay verified the inhibitory activity of the synthesized derivatives with IC50 values from 49.1 to 418.0 nM relative to the reference drug sorafenib (IC50 = 81.8 nM). Antiproliferative activity against HUVECs revealed that compounds 2-{2-[2-(6-oxo-3-phenylpyridazin-1(6H)-yl)acetyl]hydrazineyl}-N-(p-tolyl)acetamide (12c) and 2-[(5-mercapto-4-methyl-4H-1,2,4-triazol-3-yl)methyl]-6-phenylpyridazin-3(2H)-one (13a) possessed superior activity (IC50 values = 11.5 and 12.3 nM, respectively) in comparison to sorafenib (IC50 = 23.2 nM). For the purpose of appraising their antiproliferative effect, derivatives 12c and 13a were exposed to cell cycle analysis, apoptotic, cell invasion and migration assays in addition to determination of VEGFR-2 in protein level. Moreover, cytotoxicity as well as selectivity index against WI-38 cell line was measured to examine safety of derivatives 12c and 13a. After that, molecular docking study was executed on the top five compounds in the in vitro VEGFR-2 kinase assay 6d, 12c, 13a, 14a and 17c to get a deep perception on binding mode of the synthesized compounds and correlate the design strategy with biological results. Finally, physicochemical, pharmacokinetic properties, and drug-likeness studies were performed on the top five derivative in in vitro VEGFR-2 kinase assay.

Rumex vesicarius L. boosts the effectiveness of sorafenib in triple-negative breast cancer by downregulating BCl2, mTOR, and JNK, and upregulating p21 expression

BACKGROUND/AIM

Triple-negative breast cancer (TNBC) is characterized by poor prognosis, rapid progression, serious clinical behavior, an elevated risk of metastasis, and resistance to standard treatments. Traditional medicine practitioners value Rumex vesicarius L. (RMV) for a variety of reasons, including the plant's antioxidant capabilities. Our study's goals were to ascertain the efficacy of RMV alone and in combination with sorafenib (SOR) against the aggressive TNBC cell line (MDA-MB-231) and use in vitro and in silico analysis to deduce the fundamental mechanism of action.

METHODS

In the current study, molecular operating environment (MOE, 2019.0102) software was used for performing molecular docking. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was used to determine the cytotoxicity of RMV, SOR or RMV/SOR combination against the TNBC cell line MDA-MB-231 cells. The effects of RMV, SOR, and RMV and SOR combining on mRNAs expressions of the target genes including mTOR, p21, JNK, and BCl2 were evaluated. In TNBC cells, the relative expressions of mRNAs of the genes were examined by using real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

In our experiments, we discovered that both RMV extracts alone and in combination with SOR considerably reduced cancer cell proliferation (IC50 = 0.83 and 0.19 μM, respectively). Additionally, the expression of the tumor suppressor gene p21 was elevated whereas the expression of the invasion and anti-apoptosis genes BCl2, mTOR, and JNK were significantly decreased after treatment with RMV and SOR. Based on in silico analysis, it was found that RMV extract contains bioactive chemicals with a high affinity for inhibiting JNK and VEGFR-2.

CONCLUSION

In conclusion, in vitro and in silico investigations show that the RMV extract improves the anticancer efficiency of SOR through molecular processes involving the downregulation of mTOR, BCl2, and JNK1 and overexpression of p21 tumor suppressor gene. Finally, we suggest conducting additional in vivo investigations on RMV and its bioactive components to verify their potential in cancer therapy.

'In silico' repurposing new inhibitors of EGFR and VEGFR-2 kinases via biophysical mechanisms

Epidermal growth factor receptor (EGFR) controls cell growth, death, and proliferation through a variety of signaling mechanisms. The expression of vascular endothelial growth factor receptor-2 (VEGFR-2) by endothelial cells from malignant tissues triggers a series of signaling pathways that lead to tumor angiogenesis and increase cancer cell survival, proliferation, migration, and vascular permeability. The aim is to find novel inhibitors for EGFR and VEGFR-2 kinases by molecular docking drug-likeness models, pharmacokinetic, interaction analysis, and molecular dynamic simulation. Over 482 ligands were tested against the kinases, there are about 20 compounds that had the best docking scores for the 2 kinases but only compound 2C inhibited them with the highest score values by binding to active sites pocket established through molecular docking study. Secondly, the drug-likeness score of 2C was very good compared to the other compounds. The pharmacokinetics, physicochemical properties, and toxicity of 2C were much better than sorafenib and erlotinib as references. Analysis of interaction showed a strong interaction between 2C and active sites of EGFR and VEGFR-2 kinases illustrated by calculation of halogen bonds, π-Cation Interactions, Hydrogen Bonds, and Hydrophobic Interactions. Finally, the molecular dynamic simulation was also used to assess the stability of the EGFR and VEGFR-2 kinases-2C complexes. The complexes' stability was validated by RMSD, Rg, RMSF, SASA, and several hydrogen bonds analysis. 2C was shown to interact stably with pocket residues after MD simulation. Compound 2C may be a promising way to slow the signaling cascade of proteins that are significant contributors to the spread of cancer.Communicated by Ramaswamy H. Sarma.

The co-expression pattern of VEGFR-2 with indicators related to proliferation, apoptosis, and differentiation of anagen hair follicles

An increasing number of studies show that vascular endothelial growth factor is an important regulator of hair growth, and involves in processes of hair follicle development by vascularization. Recently, VEGF receptor-2 (VEGFR-2) has been detected in epithelial cells of hair follicles, indicating that it may have a direct role in the biological activity of hair follicles. To explore how VEGFR-2 regulates hair follicle development, we investigated the co-expression pattern of VEGFR-2 with β-catenin, Bax, Bcl-2, involucrin, AE13 (hair cortex cytokeratin), keratin 16, keratin 14, and Laminin 5 by immunofluorescence double staining in anagen hair follicles of normal human scalp skin. The results of double staining immunofluorescence showed a strong overlapping and similar expression pattern for VEGFR-2 with β-catenin and Bcl-2, and revealing associated expression pattern with involucrin, AE13, keratin 14, keratin 16, and Laminin 5. These results elucidated that VEGFR-2 activation may participate in hair follicle differentiation, proliferation, and apoptosis in vivo.

Anti-angiogenic potential of bioactive phytochemicals from Helicteres isora targeting VEGFR-2 to fight cancer through molecular docking and molecular dynamics simulation

Cancer is one of the leading causes of death due to its very high rate of morbidity and mortality, and there is a constant demand of effective drugs for cancer therapy. Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a significant role as central modulator of angiogenesis and is targeted frequently for developing anti-angiogenic agents to fight cancer. Helicteres isora L. (Malvaceae) is reported to possess diverse medicinal properties including anti-cancer potentials. In the current investigation, 38 bioactive phytochemicals of H. isora were screened virtually to evaluate their anti-angiogenic potentials targeting VEGFR-2. The study unveiled three potential candidates such as, Diosgenin (-9.8 Kcal//mol), Trifolin (-8.4 Kcal/mol) and Yohimbine (-8.1 Kcal/mol) that showed favorable pharmacokinetic, pharmacodynamic and toxicity properties with no significant side effects. Molecular dynamics simulation employing 100 ns revealed noteworthy structural stability and compactness for all the top three candidates. The MM/GBSA binding free energy estimation corroborated the docking interactions where Yohimbine (-30.47 Kcal/mol) scored better than Diosgenin (-27.54 Kcal/mol) and Trifolin (-29.58 Kcal/mol). Target class prediction revealed enzymes in most of the cases and some FDA approved drugs were found as structurally similar analogs for Trifolin and Yohimbine. These findings could lead to the development of novel and effective anti-angiogenic agents.Communicated by Ramaswamy H. Sarma.

Synthesis of Imidazole-2,3-dihydrothiazole Compounds as VEGFR-2 Inhibitors and Their Support with in Silico Studies

In this study, 12 novel 2-((1-(4-(1H-imidazol-1-yl)phenyl)ethylidene)hydrazineylidene)-3-ethyl-4-(substitutephenyl)-2,3-dihydrothiazole derivatives were obtained. Among these compounds, 2-((1-(4-(1H-imidazol-1-yl)phenyl)ethylidene)hydrazineylidene)-4-([1,1'-biphenyl]-4-yl)-3-ethyl-2,3-dihydrothiazole (4h) was chosen as the most active derivative in the series. According to the MTT results, compounds 4h and 4k showed activity with IC50 =4.566±0.246 μM and IC50 =4.537±0.463 μM, respectively. Unlike other derivatives, compound 4h carries a phenyl ring in the 4th position of the phenyl ring. This bulky group allowed the compound to settle in the enzyme active site. Dynamic studies show that the stability of the compound does not change over 40 ns. RMSD, RMSF and Rg parameters all remained within acceptable limits. The uninterrupted aromatic hydrogen bonding of the enzyme active site with the important amino acids Cys919, Glu885 and Asp1046 proves the inhibitory potential of compound 4h on the VEGFR-2 enzyme. It is thought that more active compounds will be reached with the derivatives to be synthesized starting from compound 4h.