Discovery of novel octahydroquinazoline scaffolds endowed with dual inhibition of tubulin polymerization/Eg5 against HCC: Apoptotic and radio-chemotherapeutic studies.

Mitotic kinesin Eg5 isozyme as a motor protein plays a critical role in cell division of tumor cells. Kinesin Eg5 selective inhibitors and Colchicine binding site suppressors are essential targets for many anticancer drugs and radio chemotherapies. On this work, a new series of octahydroquinazoline as anti-mitotic candidates 2-13 has been synthesized with dual inhibition of tubulin polymerization/Eg5 against HCC cell line. All octahydroquinazolines have been in vitro assayed against HepG-2 cytotoxicity, Eg5 inhibitory and anti-tubulin polymerization activities. The most active analogues 7, 8, 9, 10, and 12 against HepG-2 were further subjected to in vitro cytotoxic assay against HCT-116 and MCF-7 cell lines. Chalcones 9, 10, and 12 displayed the most cytotoxic potency and anti-tubulin aggregation in comparable with reference standard colchicine and potential anti-mitotic Eg5 inhibitory activity in comparison with Monastrol as well. Besides, they exhibited cell cycle arrest at the G2/M phase. Moreover, good convinced apoptotic activities have been concluded as overexpression of caspase-3 levels and tumor suppressive gene p53 in parallel with higher induction of Bax and inhibition of Bcl-2 biomarkers. Octahydroquinazoline 10 displayed an increase in caspase-3 by 1.12 folds compared to standard colchicine and induce apoptosis and demonstrated cell cycle arrest in G2/M phase arrest by targeting p53 pathway. Analogue 10 has considerably promoted cytotoxic radiation activity and boosted apoptotic induction in HepG-2 cells by 1.5 fold higher than standard colchicine.

Design, synthesis, and biological evaluation of novel pyrido-dipyrimidines as dual topoisomerase II/FLT3 inhibitors in leukemia cells.

Dual inhibition of topoisomerase (topo) II and FLT3 kinase, as in the case of C-1311, was shown to overcome the shortcomings of using topo II inhibitors solely. In the present study, we designed and synthesized two series of pyrido-dipyrimidine- and pseudo-pyrido-acridone-containing compounds. The two series were evaluated against topo II and FLT3 as well as the HL-60 promyelocytic leukemia cell line in vitro. Compounds 6, 7, and 20 showed higher potency against topo II than the standard amsacrine (AMSA), whereas compounds 19 and 20 were stronger FLT3 inhibitors than the standard DACA. Compounds 19 and 20 showed to be dual inhibitors of both enzymes. Compounds 6, 7, 19, and 20 were more potent inhibitors of the HL-60 cell line than the standard AMSA. The results of the in vitro DNA flow cytometry analysis assay and Annexin V-FITC apoptosis analysis showed that 19 and 20 induced cell cycle arrest at the G2/M phase, significantly higher total percentage of apoptosis, and late-stage apoptosis in HL-60 cell lines than AMSA. Furthermore, 19 and 20 upregulated several apoptosis biomarkers such as p53, TNFα, caspase 3/7 and increased the Bax/Bcl-2 ratio. These results showed that 19 and 20 deserve further evaluation of their antiproliferative activities, particularly in leukemia. Molecular docking studies were performed for selected compounds against topo II and FLT3 enzymes to investigate their binding patterns. Compound 19 exerted dual fitting inside the active site of both enzymes.

Design, synthesis and screening of benzimidazole containing compounds with methoxylated aryl radicals as cytotoxic molecules on (HCT-116) colon cancer cells.

A novel series of benzimidazole derivatives with methoxylated aryl groups was designed and synthesized as molecules with potential cytotoxic activity. In vitro cytotoxic activity over HCT-116 cells showed that N-(benzimidazothiazolone)acetamides 11a, 11b and 11c were found to be the most cytotoxic compounds compared camptothecin (CPT). The tested compounds had a dual topoisomerase I-ß (Topo I-ß) and tubulin inhibiting activities when compared to CPT and Podophyllotoxin (Podo) where, compounds l0a, l0b, 11a and 11b exhibited a potent inhibitory activity on Topo I-ß enzyme in nano-molar concentration, on the other hand, compounds 12b and 13b exhibited the best inhibitory activity ß-tubulin polymerization. Results of the cell cycle analysis as well as the results of annexin-V on HCT-116 cells showed that benzimidazothiazoles 12b and 13b had a pro-apoptotic activity higher than CPT by 1.33- and 1.30-folds, respectively. Moreover, the concentration of p53, Bax/Bcl-2 ratio and caspase 3/7 increased in compounds l0b, 11b, l2b, 13b, especially, compounds 11b and 13b exhibited an increased level of these mediators than CPT. Finally, compound 11b regulated the radiosensitizing activity of the HCT-116 cells by modulating the chromosomal instability.

Design, synthesis, and cytotoxic screening of novel azole derivatives on hepatocellular carcinoma (HepG2 Cells).

Novel azole derivatives 3-30 were designed, synthesized, and screened for their antitumor activity on HepG2 cell line. The cytotoxicity screening demonstrated that imidazolone 8 and triazoles 25 and 29 exhibited more potent cytotoxic activities by 1.21-, 4.75-, and 1.8-fold compared to Sorafenib (SOR). Furthermore, vascular endothelial growth factor receptor-2 (VEGFR-2) enzyme inhibition assay declared that compounds 25 and 29 had inhibitory activity at the nanomolar concentration. Moreover, the tested compounds exhibited good ß-tubulin (TUB) polymerization inhibition percentages. In addition, DNA flow cytometry analysis over HepG2 cells indicated that triazoles 25 and 29 demonstrated arrest at G1 and G2/M phase of the cell cycle and induced apoptotic activity by increasing sub-G1 phase. Finally, mechanistic studies of the proapoptotic activities of compounds 8, 10, 11, 25, and 29 indicated that they induced upregulation of P53, Fas/Fas-ligand, and BAX/BCL-2 ratio expression that resulted in increasing the active caspase 3/7 percentages and trigger apoptosis.

A new class of diamide scaffold: Design, synthesis and biological evaluation as potent antimitotic agents, tubulin polymerization inhibition and apoptosis inducing activity studies.

A new series of diamide functional compounds has been designed, synthesized and confirmed by spectroscopic methods and elemental analyses. All the synthesized compounds were evaluated for their antiproliferative activity on HepG2 cell line. Compounds 3k and 3l were proved to have potent anticancer activity equipotent or more potent than reference compound Combretastatin A-4. The results of DNA flow cytometry analysis demonstrated cell cycle arrest at G2/M phase. The extent of apoptosis induced by 3k and 3l was also determined. Moreover, the compounds produced a significant reduction in cellular microtubules for microtubule loss and potently inhibited the binding of [3H]colchicine to tubulin. Compounds 3k and 3l were proved to upregulate expression of proteins triggering apoptosis, such as p53, Bax, and decreased Bcl-2 overexpression as well as increased the expression of effector caspase- 3/7.

Design, synthesis, and screening of ortho-amino thiophene carboxamide derivatives on hepatocellular carcinomaas VEGFR-2Inhibitors.

In this work, design, synthesis, and screening of thiophene carboxamides 4-13 and 16-23 as dual vascular endothelial growth factor receptors (VEGFRs) and mitotic inhibitors was reported. All compounds were screened against two gastrointestinal solid cancer cells, HepG-2 and HCT-116 cell lines. The most active cytotoxic derivatives 5 and 21 displayed 2.3- and 1.7-fold higher cytotoxicity than Sorafenib against HepG-2 cells. Cell cycle and apoptosis analyses for compounds 5 and 21 showed cells accumulation in the sub-G1 phase, and cell cycle arrest at G2/M phase. The apoptotic inducing activities of compounds 5 and 21were correlated to the elevation of p53, increase in Bax/Bcl-2 ratio, and increase in caspase-3/7.Compounds 5 and 21 showed potent inhibition againstVEGFR-2 (IC50 = 0.59 and 1.29 µM) and ß-tubulin polymerization (73% and 86% inhibition at their IC50 values).Molecular docking was performed with VEGFR-2 and tubulin binding sites to explain the displayed inhibitory activities.

Design, synthesis and screening of 1, 2, 4-triazinone derivatives as potential antitumor agents with apoptosis inducing activity on MCF-7 breast cancer cell line.

Some triazinone derivatives are designed and synthesized as potential antitumor agents. Triazinone derivatives 4c, 5e and 7c show potent anticancer activity over MCF-7 breast cancer cells higher than podophyllotoxin (podo) by approximate 6-fold. DNA flow cytometry analysis for the compounds 3c, 4c, 5e, 6c and 7c show a potent inhibitory activity of cell proliferation and cell cycle arrest at G2/M phase. Compounds 4c, 5e and 7c exhibit low to moderate ß-tubulin polymerization inhibition percentage. Meanwhile, compound 6c displayed excellent ß-tubulin percentage of polymerization inhibition equivalent to that exhibited by podo. In addition, compounds 4c, 5e and 7c show strong topoisomerase (topo) II inhibitory activity in nano-molar concentration, compared to known topo inhibitor as etoposide. Finally, apoptotic inducing activity over MCF-7 of compounds 4c, 5e, 6c and 7c is due to up-regulation of p53, increased Bax/Bcl-2 ratio and caspase3/7 levels 2-fold higher than podo.

Design and synthesis of thienopyrimidine urea derivatives with potential cytotoxic and pro-apoptotic activity against breast cancer cell line MCF-7.

A series of novel tetrahydrobenzothieno[2,3-d]pyrimidine urea derivatives was synthesized according to fragment-based design strategy. They were evaluated for their anticancer activity against MCF-7 cell line. Three compounds 9c, 9d and 11b showed 1.5-1.03 folds more potent anticancer activity than doxorubicin. In this study, a promising multi-sited enzyme small molecule inhibitor 9c, which showed the most potent anti-proliferative activity, was identified. The anti-proliferative activity of this compound appears to correlate well with its ability to inhibit topoisomerase II (IC50 = 9.29 µM). Moreover, compound 9c showed excellent VEGFR-2 inhibitory activity, at the sub-micromolar level with IC50 value 0.2 µM, which is 2.1 folds more potent than sorafenib. Moreover, activation of damage response pathway of the DNA leads to cell cycle arrest at G2/M phase, accumulation of cells in pre-G1 phase and annexin-V and propidium iodide staining, indicating that cell death proceeds through an apoptotic mechanism. Compound 9c showed potent pro-apoptotic effect through induction of the intrinsic mitochondrial pathway of apoptosis. This mechanistic pathway was confirmed by a significant increase in the expression of the tumor suppressor gene p53, elevation in Bax/BCL-2 ratio and a significant increase in the level of active caspase-3. Quantitative structure-activity relationship (QSAR) studies delivered equations of five 3D descriptors with R2 = 0.814. This QSAR model provides an effective technique for understanding the observed antitumor properties and thus could be adopted for developing effective lead structures.