Design, synthesis and computational study of new benzofuran hybrids as dual PI3K/VEGFR2 inhibitors targeting cancer

Inhibition of Kinase Activity and In Vitro Downregulation of the Protein Kinases in Lung Cancer and Cervical Cancer Cell Lines and the Identified Known Anticancer Compounds of Ziziphus mucronata

Plants have long been used as sources of natural compounds with therapeutic benefits, providing molecules capable of inhibiting multiple kinases. Many medicinal plants are recognized for their anticancer properties and may offer ways to mitigate the adverse effects of conventional cancer treatments. In this study, the potential of Ziziphus mucronata methanol extract as a kinase inhibitor was assessed using the MTT assay, a universal kinase assay, and a human phosphokinase antibody array, along with a GC-MS analysis of volatile anticancer compounds. The MTT assay revealed strong cytotoxicity in A549 cells, with an IC50 of 31.25 µg/mL, while HeLa cells showed weaker cytotoxicity with an IC50 of 125 µg/mL. In comparison, paclitaxel exhibited potent inhibitory effects on A549 cells (IC50 of 31.25 µg/mL) and moderate inhibition on HeLa cells (IC50 of 65 µg/mL). Enzyme activity, measured by ADP production in the ADP-Glo assay, indicated that the extract inhibited protein kinase activity in both A549 and HeLa cells after 24 h of treatment. Additionally, the human phosphokinase antibody array, which includes 44 pre-spotted kinases, showed that the extract downregulated multiple phosphorylated kinases in both cell lines. Some of the affected kinases, such as TOR, Fyn, HcK, Fgr, STAT5b, PLC-γ1, p38α, ERK1/2, AMPKA, Akt1/2, GSK-3α/β, MSK1/2, CREB, RSK1/2/3, PLC-γ1, and STAT5a are critical regulators of various cellular processes, including apoptosis, differentiation, and proliferation. The findings of this study suggest that extract from Z. mucronata may have the capacity to regulate protein kinase activity, highlighting their significant potential as growth inhibitors for cancer cells.

Current developments in PI3K-based anticancer agents: Designing strategies, biological activity, selectivity, structure-activity correlation, and docking insight

The phospatidylinositol-3 kinase (PI3K) pathway is a critical intracellular signalling mechanism that is changed or amplified in a variety of cancers, including breast, gastric, ovarian, colorectal, prostate, glioma, and endometrial. PI3K signalling is important for cancer cell survival, angiogenesis, and metastasis, making it a promising therapeutic target. The PI3K kinases in their different isoforms, namely α, β, δ, and γ, encode PIK3CA, PIK3CB, PIK3CD, and PIK3CG genes. Specific gene mutation or overexpression of the protein is responsible for the therapeutic failure of current therapeutics. There are several current and completed clinical trials using PI3K inhibitors (pan, isoform-specific, and dual PI3K/mTOR) to develop effective PI3K inhibitors capable of overcoming resistance to existing drugs. However, the bulk of these inhibitors have had their indications revoked or voluntarily withdrawn due to concerns about their harmful consequences. Several inhibitors containing medicinally privileged scaffolds like thiazole, triazine, benzimidazole, podophyllotoxin, pyridine, quinazoline, thieno-triazole, pyrimidine, triazole, benzofuran, imidazo-pyridazine, oxazole, coumarin, and azepine derivatives have been explored to target the PI3K pathway and/or a specific isoform in the current overview. This article reviews the structure, biological activities, and clinical status of PI3K inhibitors. It focuses on the development techniques, docking insight, and structure-activity connections of PI3K-based inhibitors. The findings provide useful insights and future approaches for the development of promising PI3K-based inhibitors.

Synthesis and structural proof of novel oxazolo[5,4-d]pyrimidine derivatives as potential VEGFR2 inhibitors. In vitro study of their anticancer activity

The present study aimed to design and synthesize novel 6-N-benzyloxazolo[5,4-d]pyrimidin-7(6H)-imines 3a-j as possible inhibitors of the vascular endothelial growth factor receptor 2 (VEGFR2). The structures of newly synthesized compounds were confirmed via spectral and crystallographic data. NOESY spectroscopy was very useful in distinguishing between 6-N-benzyl-7(6H)-imine 3a and isomeric 7-N-benzyl-7-amine 4a, obtained by Dimroth rearrangement. Molecular docking at the VEGFR2 active site was performed, indicating that 7(6H)-imines should have a similar binding mode as type II VEGFR2 inhibitors. All derivatives were preliminary evaluated for in vitro cytotoxic activity against four human cancer cell lines, including lung cancer (A549), colorectal cancer (HT-29), melanoma (A375), breast cancer (MCF7), using tivozanib as a reference drug, and some of them were subjected to VEGFR2 inhibition, anti-angiogenic activity, and human serum albumin (HSA) binding assays. Only 6-N-2,4-dimethoxybenzyl derivative 3h appeared to be as active as tivozanib against all tested anticancer cell lines but equally toxic to healthy normal human dermal fibroblasts (NHDF). Derivatives 3f (6-N-2-methybenzyl) and 3b (6-N-4-methylbenzyl) have revealed slightly worse activity than 3h. They were cytotoxic agents comparable to tivozanib against three anticancer lines, but only 3b showed no cytotoxicity against NHDF. Both 3b and 3h proved to be effective VEGFR2 inhibitors with IC50 values comparable to that of tivozanib. Notably, 4a did not actually show an anticancer effect against the tested cancer lines, in contrast to isomeric 3a. In an angiogenesis assay, 3f and 3h significantly suppressed the tube formation ability of human dermal microvascular endothelial cells (HMEC-1), indicating their anti-angiogenic potential. The interactions between these compounds and HSA appeared to occur at two specific binding sites.

Recent updates on potential of VEGFR-2 small-molecule inhibitors as anticancer agents

The vascular endothelial growth factor receptor (VEGFR) system is the key component for controlling angiogenesis in cancer cells. Blocking vascular endothelial growth factor receptor 2 (VEGFR2) signalling is one of the most promising approaches to hindering angiogenesis and the subsequent growth of cancer cells. The USFDA-approved small-molecule drugs targeting VEGFR-2 are developing drug resistance over the course of chemotherapy, and cardiac-related side effects are consistently being reported; hence, there is an urgent need for more safe and effective anticancer molecules. The present review focuses on the structure and physiology of VEGFR-2 and its involvement in the progression of cancer cells. The recent updates from the last five years through papers and patents on structure-activity relationships, pharmacophoric attributes, molecular docking interactions, antiangiogenic assays, cancer cell line studies, and the potencies (IC50) of VEGFR-2 inhibitors are discussed herein. The common structural framework requirements, such as the Asp-Phe-Gly (DFG) motif of VEGFR-2 interacting with the HBD-HBA region in the ligand molecules, the central aryl ring occupying the linker region, and a variety of bio-isosteres, can enhance activity against VEGFR-2. At one end, the heteroaryl moiety is essential for interaction within the ATP-binding site of VEGFR-2, while the terminal hydrophobic tail occupies the allosteric binding site. Three to five bond spacers between the heteroaryl and HBD-HBA regions provided a better result towards VEGFR-2 inhibition, mirroring the behaviors of standard drugs. The in-depth analysis of recent updates on VEGFR-2 inhibitors presented in this paper will help prospective synthetic and medicinal chemists to discover new lead molecules for the treatment of various cancers.

BM7, a derivative of benzofuran, effectively fights cancer by promoting cancer cell apoptosis and impacting IL-6 levels

The BM7 compound, a bromo derivative of methyl 6-acetyl-5-hydroxy-2-methyl-1-benzofuran-3-carboxylate, was previously identified as cytotoxic to human leukaemia cells (K562 and HL60) and human cervical cancer (HeLa), while showing no toxicity to non-cancerous primary endothelial cells (HUVEC). In this study, we present the first demonstration of BM7's anticancer efficacy in vivo using a mouse chronic myeloid leukaemia xenograft model. Administered intraperitoneally in a mixture of 10% Solutol HS 15/10% ethanol, BM7 exhibited no visible toxicity and significantly reduced tumor weight, comparable to standard drugs imatinib and hydroxyurea. Further supporting its anticancer potential, a multi-model in vitro study involving seven human cancer cell lines revealed the most promising responses in colon cancer (SW480, SW620, HCT116), liver cancer (HEPG2), and breast adenocarcinoma (MDA-MB-231) cells. BM7 demonstrated multifaceted anticancer mechanisms, inducing apoptosis while elevating reactive oxygen species (ROS) levels and suppressing interleukin-6 (IL-6) release in these cell lines. These findings position BM7 as a candidate of significant interest for cancer therapy. Its ability to not only induce apoptosis but also modulate cellular processes such as ROS levels and immune responses, specifically IL-6 suppression, makes BM7 a versatile and promising agent for further exploration in the realm of cancer treatment.

Microtubule destabilising activity of selected 7-methoxy-2-phenylbenzo[b]furan derivative against primary and metastatic melanoma cells

Herein, we report the results of anticancer screening of two 2-phenylbenzo[b]furan derivatives functionalised at the 3-position with 4-hydroxy-3,5-dimethoxybenzoyl (BF2) or 3,4,5-trimethoxybenzoyl (BF3) against 60 different cancer cell lines. The results confirmed the anticancer potential of the tested compounds against different cancer cell types, especially colon cancer, brain cancer and melanoma. BF3 was defined as the most potent (also as a tubulin polymerisation inhibitor). Its anticancer activity against melanoma cell lines that originated from different stages, i.e., primary skin-derived A375 and metastatic WM9/MDA-MB-435S, was evaluated (as the clinical success of melanoma therapy strictly depends on the disease stage). Moreover, to determine the BF3 mode of action and its effect on cell proliferation, intracellular microtubule networks, cell cycle phase distribution and apoptosis were evaluated. Our study revealed that BF3 inhibited cell proliferation in a dose-dependent manner, with IC50 yielding 0.09 ± 0.01 μM, 0.11 ± 0.01 μM and 0.18 ± 0.05 μM for A375, MDA-MB435S and WM9, respectively. The strong antiproliferative activity of compound BF3 correlated well with its inhibitory effect on tubulin polymerisation. Molecular docking proved that BF3 belongs to the colchicine binding site inhibitors (CBSIs), and experimental studies revealed that it disturbs cell cycle progression leading to G2/M arrest and apoptosis.

Design, Synthesis, Docking Study, and Antiproliferative Evaluation of Novel Schiff Base-Benzimidazole Hybrids with VEGFR-2 Inhibitory Activity

A new series of Schiff-benzimidazole hybrids 3a-o has been designed and synthesized. The structure of the target compounds was proved by different spectroscopic and elemental analysis tools. The target compounds were evaluated for their in vitro cytotoxic activity against 60 cancer cell lines according to NCI single- and five-dose protocols. Consequently, four compounds were further examined against the most sensitive lung cancer A549 and NCI-H460 cell lines. Compounds 3e and 3g were the most active, achieving 3.58 ± 0.53, 1.71 ± 0.17 and 1.88 ± 0.35, 0.85 ± 0.24 against A549 and NCI-H460 cell lines, respectively. Moreover, they showed remarkable inhibitory activity on the VEGFR-2 TK with 86.23 and 89.89%, respectively, as compared with Sorafenib (88.17%). Moreover, cell cycle analysis of NCI-H460 cells treated with 3e and 3g showed cellular cycle arrest at both G1 and S phases (supported by caspases-9 study) with significant pro-apoptotic activity, as indicated by annexin V-FITC staining. The binding interactions of these compounds were confirmed through molecular docking studies; the most active compounds displayed complete overlay with, and a similar binding mode and pose to, Sorafenib, a reference VEGFR-2 inhibitor.