New Series of VEGFR-2 Inhibitors and Apoptosis Enhancers: Design, Synthesis and Biological Evaluation.

Background: Cancer is still a major world health threat, causing a high rate of mortality. VEGFR-2 inhibitor anticancer agents are of great significance. However, they showed some serious side effects. Purpose: To discover new effective and safer anticancer agents, a new series of piperazinylquinoxaline-based derivatives was designed and synthesized on the basis of the pharmacophoric features of VEGFR-2 inhibitor drugs. Methods: The new candidates were evaluated against A549 lung cancer cells, HepG-2 hepatoma cells, Caco-2 colon cancer cells, MDA breast cancer cells, and VEGFR-2 kinase. Moreover, cell cycle kinetics and apoptosis rates were studied in HepG-2 cells treated with compound 11, which was the most promising candidate. Results: The new derivatives revealed better antitumor results (IC50 from 6.48 to 38.58 µM) against the aforementioned cancer cell lines than sorafenib. Also, the new candidates showed VEGFR-2 inhibition with IC50 values ranging from 0.19 to 0.60 µM compared to 0.08 µM for sorafenib. Compound 11, meanwhile, showed IC50 values equal to 10.61, 9.52, 12.45, 11.52, and 0.19 µM against the cancer cell lines and VEGFR-2, respectively. Moreover, compound 11 raised the apoptosis rate in HepG-2 cells from 5% to 44% and caused 4, 2.3, and 3-fold increases in BAX/Bcl-2 ratio, caspase-3 level, and P53 expression, respectively, compared to control untreated cells. Finally, the new derivatives displayed the correct binding mode into VEGFR-2 kinase pocket, giving interactions with the essential residues. Conclusion: This work suggests that compound 11 is a very significant anticancer candidate, and piperazinylquinoxaline is an important scaffold in the development of new potential effective and safer VEGFR-2 inhibitor agents.

Synthesis and Biological Evaluation of Novel Indomethacin Derivatives as Potential Anti-Colon Cancer Agents.

The molecular structure of indomethacin was used as a starting scaffold for the synthesis of 20 novel analogs and to study their effects on the proliferation of three human colon cancer cell lines, HCT-116, HT-29, and Caco-2, by MTT assay. The synthesized indomethacin analogs were characterized on the basis of IR, 1 H NMR, 13 C NMR, mass spectral data, and elemental analysis results. Cytotoxicity assay results showed that the indomethacin amide analog 2 was the most potent anticancer agent (IC50 = 0.78, 0.09, and 0.0127 µg/mL) against the three colon cancer cell lines, respectively, being more potent than the standard 5-fluorouracil (IC50 = 1.8, 0.75, and 5.45 µg/mL). Interestingly, the indomethacin oxazin analog 3 and the indomethacin amide analog 8 displayed very potent anticancer activity against the HCT-116 cell line with IC50 = 0.421 and 0.27 µg/mL, respectively, much better than the reference (IC50 = 1.8 µg/mL). Additionally, analogs 3, 4b, 11, 12c, and 13a exhibited excellent antitumor activity against Caco-2 cells, with IC50 ranging from 1.5 to 4.5 µg/mL. Furthermore, analogs 2 and 8 were additionally examined for their effect on the cell cycle of HCT-116 and HT-29 cells, respectively, using flow cytometric analysis. Analog 2 arrested the cell cycle of HT-29 cells at the S phase, while 8 was found to arrest the cell cycle of HCT-116 cells at the G0/G1 phase.