Upregulation of BAX and caspase-3, as well as downregulation of Bcl-2 during treatment with indeno[1,2-b]quinoxalin derivatives, mediated apoptosis in human cancer cells.

Cancer is the world's foremost cause of death. There are over 100 different forms of cancer. Cancers are frequently named after the organs or tissues in which they develop. As a part of our aim to develop promising anticancer agents, a series of new indeno[1,2-b]quinoxaline derivatives were synthesized. All of the synthesized compounds were tested for anticancer activity in vitro in three human cancer cell lines: the HCT-116 colon cancer cell line, the HepG-2 liver cancer cell line, and the MCF-7 breast cancer cell line. Among the tested derivatives, 2, 3, 5, 12, 21, and 22 showed exceptional antiproliferative activities against the three tested cell lines compared to the reference standard imatinib. These compounds were, therefore, selected for further investigations. Evaluation of their cytotoxicity against a normal human cell line (WI-38) was performed, to ensure their safety and selectivity (IC50 > 92 µM). Then, induction of apoptosis by the most active compounds was found to be accomplished by downregulation of Bcl-2 and upregulation of BAX and caspase-3. After that, the most promising apoptotic compound that increases the caspase-3 and BAX expression and downregulates Bcl-2 activity (3) was assessed for its impact on the cell cycle distribution in HepG-2 cells: The most potent derivative (3) induced cell cycle arrest at the G2/M phase. Finally, in silico evaluation of the ADME properties indicated that compound 3 is orally bioavailable and can be readily synthesized on a large scale.

Novel structural hybrids of quinoline and thiazole moieties: Synthesis and evaluation of antibacterial and antifungal activities with molecular modeling studies.

One of the best ways to design new biocidal agents is synthesizing hybrid molecules by combining two or more bioactive moieties in a single molecular scaffold. So, new series of quinolines bearing a thiazole moiety were synthesized using thiosemicarbazones 2a-f. Cyclization of 2a-f with ethyl chloroacetate, ethyl 2-chloropropanoate or chloroacetone afforded the corresponding thiazoles 3-5. The antimicrobial activity of the new quinoline derivatives was evaluated. The most of tested compounds revealed potent both of the antibacterial and antifungal activities. Fourfold potency of amphotericin B for the inhibition the growth of the A. fumigatus was displayed by ccompound 5e. The latter compound displayed twofold potency of gentamycin for inhibition the growth of N. gonorrhoeae. Moreover, this compound showed equipotent potency of references drugs for inhibition of the growth of S. flexneri, S. pyogenes, P. vulgaris, A. clavatus, G. candidum and P. marneffei. So, quinolines bearing a thiazole moiety can be suggested as interesting scaffolds for the development both of the novel antibacterial and antifungal agents. Some new derivatives were studied as peptide deformylase enzyme inhibitors. Thiazolidin-4-one derivative 3d and 2,3-dihydrothiazole derivative 5c had shown good PDF inhibition activity, which had been supported by the docking results with highest binding affinity and lowest docking energy score. These results suggested that the most potent compounds might be possible agents as novel bacterial PDF inhibitor.

Synthesis of new arylazopyrazoles as apoptosis inducers: Candidates to inhibit proliferation of MCF-7 cells.

New 4-arylazo-3,5-diamino-1H-pyrazole derivatives substituted in the 4-aryl ring with the acetyl moiety were designed and synthesized. The antiproliferative activity of the novel arylazopyrazoles was examined against the MCF-7 cell line. Among all target compounds, 8b (IC50 3.0 µM) and 8f (IC50 4.0 µM) displayed higher cytotoxicity as compared with the reference standard imatinib (IC50 7.0 µM). Further studies to explore the mechanism of action were performed on the most active hit of our library, 8b, via anti-CDK2 kinase activity. It demonstrated good inhibitory effects for CDK2 (IC50 0.24 µM) with 62.5% inhibition, compared with imatinib. The cell cycle analysis in the MCF-7 cell line revealed apoptosis induction by 8b and cell cycle arrest at the S phase. Docking in the CDK2 active site and pharmacophore modeling confirmed the affinity of 8b to the CDK2 active site. Absorption, distribution, metabolism, and excretion studies revealed that our target compounds are orally bioavailable, with no permeation through the blood-brain barrier.

New cyanopyridine-based scaffold as PIM-1 inhibitors and apoptotic inducers: Synthesis and SARs study.

Two novel series of 6-(4-benzamido-/4-phthalimido)-3-cyanopyridine derivatives were designed and synthesized as inhibitors of PIM-1 kinase. Based on cytotoxicity results via MTT assay against prostate carcinoma PC3, human hepatocellular carcinoma HepG2 and breast adenocarcinoma MCF-7 cell lines, the most potent cytotoxic cyanopyridine hits, 6, 7, 8, 12 and 13 were 1.5-3.3 times more inhibitor of cell proliferation than the reference standard, 5-FU. Selectivity profile of the latter compounds on normal human cells (WI-38), was executed, indicating that they are highly selective (IC50 > 145 µM) in their cytotoxic effect. The promising compounds were further evaluated as PIM-1 kinase inhibitors. These compounds elicited remarkable inhibition of PIM-1 kinase (76.43-53.33%). Extensive studies on apoptosis were conducted for these compounds; they enhanced caspase-3 and boosted the Bax/Bcl-2 ratio 27-folds in comparison to the control. Molecular docking study of the most potent compound, 13 in PIM-1 kinase active site was consistent with the in vitro activity. Finally, prediction of chemo-informatic properties released compound 13 as the most promising ligand.

In vitro cytotoxic activity of thiazole-indenoquinoxaline hybrids as apoptotic agents, design, synthesis, physicochemical and pharmacokinetic studies.

In this study, anti-proliferative effects of twenty-seven indeno[1,2-b]quinoxalin-11-one derivatives were investigated in three human cancer cell lines, namely: the colon cancer cell line HCT-116, the liver cancer cell line HepG-2, and the breast cancer cell line MCF-7. Among them, 5, 6, 13, 14a, b and 15d-f derivatives displayed excellent anti-proliferative activities against the three tested cell lines compared to the reference standard Imatinib. Therefore, they were selected for further studies. First, to ensure the safety of our hits, investigation of the IC50 values on normal human cells (WI-38) was executed indicating that, they are highly selective (IC50 > 107 µM) in their cytotoxic effect. Second, the induction of apoptosis by these active compounds was achieved by down-regulation of Bcl-2 and up-regulation of BAX and caspase-3. Further investigations have shown that 14b and 15f, the most potent derivatives, induced cell cycle arrest at G2/M phase. Moreover, in silico evaluation of ADME properties indicated that all the potent compounds are orally bioavailable with no permeation to the blood brain barrier.

Apoptosis: A target for anticancer therapy with novel cyanopyridines.

One of the many methods of treating cancer is to terminate the uncontrolled growth of cancer cells. So, aiming the apoptotic pathway is an exciting approach to finding new anticancer agents. A novel series of cyanopyridines was designed and synthesized for antiproliferative evaluation. 2-Amino-6-(4-(benzyloxy)phenyl)-4-(4-(dimethylamino)phenyl) nicotinonitrile 10f was the most potent inhibitor against the growth of PC-3, and HepG-2 cancer cell lines with IC50 values of 2.04 uM (selectivity index, SI = 78.63, 43, respectively). Also, 10f was safe against the growth of normal human diploid lung fibroblasts cell line (WI-38) with an IC50 value of 160.04 uM. Its analogs, 10b, 10d, 10g, and 11b, were also active against the growth of PC-3, and HepG-2 while against MCF-7 cell line, they displayed good cytotoxic activity compared to the reference standard 5-FU. Remarkably, mechanistic studies indicated that compounds 10b, 10d, 10f, 10g, and 11b stimulated the level of active caspase 3 and boosted the BAX/BCL2 ratio 20-95 folds in comparison to the control. Our results have also indicated that 10b, 10d, 10f, 10g, and 11b exhibited a very potent inhibitory activity against PIM-1 kinase enzyme, where the IC50 values unraveled very potent molecules in the micromolar range (0.47-1.27 µM). Further investigations have shown that 10f, the most potent PIM-1 kinase inhibitor, induced a cell cycle arrest at the G2/M phase. Moreover, in silico evaluation of ADME properties indicated that all the cyanopyridine compounds are orally bioavailable with no permeation to the blood brain barrier.

Novel 1,3,4-Triaryl Pyrazoles: Synthesis, QSAR Studies and Cytotoxicity against Breast Cancer.

BACKGROUND: The existence of drug-resistance and lack of selectivity encourages scientists to search for novel and more selective cytotoxic agents. OBJECTIVES: In this work, novel 1,3,4-triarylpyrazole derivatives were synthesized to study their cytotoxicity on MCF7 (human breast Cell Line). In addition, QSAR studies were performed to show the relation between the cytotoxic activity and the structural features of our new synthesized pyrazole derivatives. METHODS: Pyrazole-4-carbaldehyde derivative 3 was utilized as a starting material for the preparation of the new pyarazole derivatives. These target compounds were screened for their cytotoxic activity against MCF-7 followed by study cell cycle of the most active compounds. Finally, pharmacophore modeling and QSAR Studies was carried out. RESULTS: Among these compounds; 5d and 8b showed the highest anti-proliferative activity (IC50 = 4.9 and 2.11 µM, respectively). Flow cytometric analysis showed that, compounds 5d and 8b arrested the cell cycle in addition to induction of apoptosis in MCF7 cells. Moreover, their stimulation effect on caspases 3/7 was examined to explore their mechanism of induction of apoptosis and the results showed that their proapoptotic activity could be due to the activation of caspases 3/7. CONCLUSION: Pyrazole derivatives 5d and 8b displayed potent bioactivities, indicating that these compounds could be considered as a new lead for more investigation in the future.

New thiobarbituric acid scaffold-based small molecules: Synthesis, cytotoxicity, 2D-QSAR, pharmacophore modelling and in-silico ADME screening.

A series of twenty five new thiobarbituric acid derivatives, viz. 3a-h, 4-7, 8a-c, 9, 10a-c, 11 and 12a-d, were designed and synthesized as potential cytotoxic agents. In-vitro screening of the new compounds against the three human cancer cell lines Caco-2, HepG-2 and MCF-7 was performed to assess their intrinsic activity. Compound 12d exhibited potent sub-micromolar activity against HepG-2 and MCF-7 (IC50 = 0.07 and 0.08 µM, respectively). In-silico pharmacophore modelling of this chemotype compounds disclosed a five features' pharmacophore model representing essential steric and electronic fingerprints essential for activity. Finally, a 2D-QSAR model was devised to quantitatively correlate the 2D molecular feature descriptors of this series of thiobarbiturates with their cytotoxic activity against MCF-7. Finally, in silico evaluation of the physicochemical and ADME properties of these derivatives was performed.