Benzoxazole-appended piperidine derivatives as novel anticancer candidates against breast cancer.

Novel series of benzoxazole-appended piperidine derivatives were planned, synthesized and screened against two breast cancer cell lines. Considerable antiproliferative activity was observed for screened compounds (IC50 = 33.32 ± 0.2 µM to 7.31 ± 0.43 µM and 1.66 ± 0.08 µM to 12.10 ± 0.57 µM) against MCF-7 and MDA-MB-231 cell lines respectively being more potent than doxorubicin (IC50 = 8.20 ± 0.39 µM and 13.34 ± 0.63 µM respectively). Active compounds were submitted for enzyme inhibition assays when 4d and 7h demonstrated potent EGFR inhibition (0.08 ± 0.002 µM and 0.09 ± 0.002 µM respectively) compared to erlotinib (0.11 ± 0.003 µM). However, no one compound displayed effective ARO inhibition activity as tested compounds were less active than letrozole. Apoptosis inducing ability results implied that apoptosis was provoked by significant stimulation of caspase-9 protein levels (4.25-7.04-fold) upon treatment of MCF-7 cells with 4a, 7h, 9, 12e and 12f. Alternatively, MDA-MB-231 cells treated with 4d, 7a, 12b and 12c considerably increased caspase-9 levels (2.32-4.06-fold). Cell cycle arrest and annexin-V/Propidium iodide assays further confirmed apoptosis when tested compounds arrested cell cycle at various phases and demonstrated high annexin V binding affinity. Docking outcomes proved valuable binding affinities for compounds 4d and 7h to EGFR enzyme while compounds 4a and 12e, upon docking into the active site of ARO, failed to interact with heme, suggesting their inabilities to act as AIs. Therefore, these benzoxazoles can act as promising candidates exhibiting EGFR inhibition and apoptosis-promoting properties.

New functionalized 6-thienylpyrimidine-5-carbonitriles as antiproliferative agents against human breast cancer cells.

6-Thienylpyrimidine-5-carbonitrile derivatives were synthesized and screened for their in vitro antiproliferative activities against two human breast cancer cell lines in comparison to 5-fluorouracil as a reference. Compounds 2, 3a-c, and 6b evolved as the most active congeners against both cell lines, while others showed selectivity for only one cell line. Compound 2 exerted its effect through inhibition of the epidermal growth factor receptor (EGFR), while 6b showed less aromatase inhibitory activity than letrozole. The rest of the tested compounds did not show significant inhibition, and it can be assumed that they exert their antiproliferative activity through different target mechanisms. In addition, caspase-9 protein activation assays, cell cycle analysis using flow cytometry, and annexin V-fluorescein isothiocyanate-propidium iodide (FITC/PI) dual staining assays were performed for the most active compounds. All the tested compounds were found to be potent pyrimidine derivatives able to initiate apoptosis in MCF-7 and MDA-MB-231 cells.

2-Anilinopyrimidine derivatives: Design, synthesis, in vitro anti-proliferative activity, EGFR and ARO inhibitory activity, cell cycle analysis and molecular docking study.

Novel anti-proliferative agents possessing pyrimidine scaffolds were designed, synthesized and evaluated for their IC50 values using MTT assay. Most compounds displayed good to excellent activity against the two tested breast cancer lines (MCF-7 and MDA-MB-231) as compared to 5-FU. The observed IC50 values for active compounds ranged from 0.27 to 10.57 µM in MCF-7 compared to the reference drug 5-FU (IC50 = 10.80 µM) and from 0.73 to 29.07 µM in MDA-MB-231 (IC50 for 5-FU = 11.40 µM). SAR analysis indicated that compounds 2c, 3b with hydrazone functionalities and compound 12 possessing pyrazolone ring exhibited superior activities. The most promising compounds were evaluated for their inhibitory activity against epidermal growth factor receptor (EGFR) and aromatase (ARO) enzymes and were further tested for caspase-9 activation, apoptosis and Annexin V/PI staining. Results of enzyme-based experiments indicated that the tested compounds 2c and 12 exert their activities through EGFR inhibition while compound 3b exhibited remarkable ARO inhibition activity. Furthermore, they remarkably induce caspase-9 activation and showed pre G1 apoptosis and cell cycle arrest at G2/M phase. In addition, docked compounds displayed good binding affinities to the target enzymes. Binding interaction details for the most promising inhibitors with the active site of the target enzymes EGFR and ARO utilizing MOE-dock method are also reported.