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.

New benzothiazole hybrids as potential VEGFR-2 inhibitors: design, synthesis, anticancer evaluation, and in silico study.

A new series of 2-aminobenzothiazole hybrids linked to thiazolidine-2,4-dione 4a-e, 1,3,4-thiadiazole aryl urea 6a-d, and cyanothiouracil moieties 8a-d was synthesised. The in vitro antitumor effect of the new hybrids was assessed against three cancer cell lines, namely, HCT-116, HEPG-2, and MCF-7 using Sorafenib (SOR) as a standard drug. Among the tested compounds, 4a was the most potent showing IC50 of 5.61, 7.92, and 3.84 µM, respectively. Furthermore, compounds 4e and 8a proved to have strong impact on breast cancer cell line with IC50 of 6.11 and 10.86 µM, respectively. The three compounds showed a good safety profile towards normal WI-38 cells. Flow cytometric analysis of the three compounds in MCF-7 cells revealed that compounds 4a and 4c inhibited cell population in the S phase, whereas 8a inhibited the population in the G1/S phase. The most promising compounds were subjected to a VEGFR-2 inhibitory assay where 4a emerged as the best active inhibitor of VEGFR-2 with IC50 91 nM, compared to 53 nM for SOR. In silico analysis showed that the three new hybrids succeeded to link to the active site like the co-crystallized inhibitor SOR.

Development of new thiazolidine-2,4-dione hybrids as aldose reductase inhibitors endowed with antihyperglycaemic activity: design, synthesis, biological investigations, and in silico insights.

This research study describes the development of new small molecules based on 2,4-thiazolidinedione (2,4-TZD) and their aldose reductase (AR) inhibitory activities. The synthesis of 17 new derivatives of 2,4-TZDs hybrids was feasible by incorporating two known bioactive scaffolds, benzothiazole heterocycle, and nitro phenacyl moiety. The most active hybrid (8b) was found to inhibit AR in a non-competitive manner (0.16 µM), as confirmed by kinetic studies and molecular docking simulations. Furthermore, the in vivo experiments demonstrated that compound 8b had a significant hypoglycaemic effect in mice with hyperglycaemia induced by streptozotocin. Fifty milligrams per kilogram dose of 8b produced a marked decrease in blood glucose concentration, and a lower dose of 5 mg/kg demonstrated a noticeable antihyperglycaemic effect. These outcomes suggested that compound 8b may be used as a promising therapeutic agent for the treatment of diabetic complications.

Design, synthesis, antitumor, and VEGFR-2 inhibition activities of novel 4-anilino-2-vinyl-quinazolines: Molecular modeling studies.

The antitumor activity of newly synthesized 4-anilino-2-vinylquinazolines 8a-r was measured comparable to sorafenib as a standard drug. The 2-vinylquinazolines 8a-r were evaluated for their in vitro antitumor activity. The most active antitumor agents were subjected to in vitro VEGFR-2 inhibition and apoptotic inducing assay. Compounds 8 h, 8 l, and 8r showed potential antitumor activities with IC50 values of 4.92-14.37 µM relative to the reference drug, sorafenib (IC50 values of 5.47-9.18 µM). Compound 8 h possessed potential VEGFR-2 inhibitory activity (IC50 = 60.27 nM) compared to standard drug sorafenib (IC50 = 55.43 nM), whereas compound 8 l showed moderate inhibitory activity (IC50 = 93.50 nM). The most active compound, 8 h, exhibited total apoptosis with 36.24% on MCF-7 cells, more than the apoptotic effect provoked by sorafenib (32.46%) and the cell cycle arrested at a G1/S phase. Compound 8 h, a potent VEGFR-2 inhibitor, was docked into the VEGFR-2 binding pocket, where this compound showed binding interaction similar to co-crystallized inhibitor sorafenib.

Quinazoline Based HSP90 Inhibitors: Synthesis, Modeling Study and ADME Calculations Towards Breast Cancer Targeting.

A new 2-thioquinazolinones series was designed and synthesized as HSP90 inhibitors based on the structure of hit compound VII obtained by virtual screening approach. Their in vitro anti-proliferative activity was evaluated against three human cancer cell lines rich in HSP90 namely; colorectal carcinoma (HCT-116), and cervical carcinoma (Hela), breast carcinoma (MCF-7). Compounds 5a, 5d, 5e and 9h showed a significant broad spectrum anti-proliferative activity against all tested cell lines. They were characterized by potent effect against breast cancer in particular with IC50 of 11.73, 8.56, 7.35 and 9.48 µM, respectively against Doxorubicin (IC50 4.17 µM). HSP90 ATPase activity inhibition assay were conducted where compound 5d exhibited the best IC50 with 1.58 µM compared to Tanespimycin (IC50 = 2.17 µM). Compounds 5a and 9h showed higher IC50 values of 3.21 and 3.41 µM, respectively. The effects of 5a, 5d and 9h on Her2 (a client proteins of HSP90) and HSP70 were evaluated in MCF-7 cells. All tested compounds were found to reduce Her2 protein expression levels and induce Hsp70 protein expression levels significantly, emphasizing that antibreast cancer effect is a consequence of HSP90 chaperone inhibition. Cell cycle analysis of MCF-7 cells treated with 5d showed cell cycle arrest at G2/M phase 38.89% and pro-apoptotic activity as indicated by annexin V-FITC staining by 22.42%. Molecular docking studies suggested mode of interaction to HSP90 via hydrogen bonding. ADME properties prediction of the active compounds suggested that they could be used as orally absorbed anticancer drug candidates.

Synthetic approaches, anticancer potential, HSP90 inhibition, multitarget evaluation, molecular modeling and apoptosis mechanistic study of thioquinazolinone skeleton: Promising antibreast cancer agent.

New series of compounds bearing 2-thioquinazolinone scaffold were designed, synthesized as HSP90 inhibitors. Anti-proliferative activity of the synthesized compounds was evaluated against HCT-116, Hela and MCF-7 cell lines and compound 5k was found to be the most active member of the entire study with IC50 of 4.47, 7.55 and 4.04 µM, respectively, compared to DOX (IC50 of 5.23, 5.57 and 4.17 µM, respectively). Most of the tested compounds revealed lower cytotoxicity against normal fibroblast cells WI-38. Compounds 5b, 5k and 8a showed potent HSP90 inhibitory activities with IC50 values in nanomolar range; 71.32, 25.07 and 56.78 nm, respectively, against Tanespimycin (IC50 of 86.45 nm). Their HSP90 inhibitory activities were confirmed by their down regulation of HSP90 client protein Her2 and up regulation of chaperone HSP70 levels. Compound 5k had shown potent multi-target inhibitory activities against EGFR, VEGFR-2 and Topoisomerase-2 with IC50 values in nanomolar range; 38.5, 126.95 and 25.85 nm, respectively. Compound 5k was further evaluated for cell cycle distribution and apoptosis induction on MCF-7 cells using flow cytometry. Compound 5k arrested the cell cycle on MCF-7 at a G2/M phase by 35.06% and induced apoptosis by 19.82%. Mechanistic evaluation of apoptosis induction was studied by following ways triggering mitochondrial apoptotic pathway through inducing ROS accumulation, increasing Bax/Bcl-2 ratio and activation of caspases 6, 7 and 9. Comparative molecular modeling study was performed between active and inactive HSP90 inhibitors. Docking studies into the active site of HSP90 N-terminal domain showed good agreement with the obtained biological results. ADMET analysis and parameters of Lipinski's rule of five were calculated where compound 5k had reasonable drug-likeness with acceptable physicochemical properties so it could be used as promising orally absorbed antibreast targeted therapy.

S-Alkylated quinazolin-4(3H)-ones as dual EGFR/VEGFR-2 kinases inhibitors: design, synthesis, anticancer evaluation and docking study.

Dual targeting by a single molecule has emerged as a promising strategy for fighting cancer. In this study, a new set of 2-thioquinazolin-4(3H)-ones as potential anti-cancer surrogates endowed with dual EGFR/VEGFR-2 kinases inhibitory activities were synthesized. The anti-tumor potency of the newly synthesized candidates 4-27 was evaluated against a panel of four cancer cell lines. The prepared candidates 4-27 showed comparable activity to that of the standard drug sorafenib. For instance, compound 4 (IC50 = 1.50-5.86 µM) and compound 20 (IC50 = 4.42-6.39 µM) displayed superior potencies against all cell lines compared to sorafenib (IC50 = 5.47-7.26 µM). Dual EGFR/VEGFR-2 inhibitory activities of the most active analogues (4, 11, and 20) were investigated. Compound 4 showed comparable EGFR/VEGFR-2 inhibitory activity to the used control drugs. Flow cytometric analysis indicates that the most potent analogue 4 stopped the cell cycle at the G1 phase and induced 46.53% total apoptosis in HCT-116 cells that was much more powerful than the untreated cells with 2.15% apoptosis. Molecular docking and dynamic simulations of 4, 11, and 20 with EGFR and VEGFR-2 were performed to examine the binding mode and interaction within the enzyme binding pockets.