Apoptosis induction in human leukemia cells by novel 2-amino-5-benzylthiazole derivatives

Development of Novel Pyridine-Thiazole Hybrid Molecules as Potential Anticancer Agents

Novel pyridine-thiazole hybrid molecules were synthesized and subjected to physico-chemical characterization and screening of their cytotoxic action towards a panel of cell lines derived from different types of tumors (carcinomas of colon, breast, and lung, glioblastoma and leukemia), and normal human keratinocytes, for comparison. High antiproliferative activity of the 3-(2-fluorophenyl)-1-[4-methyl-2-(pyridin-2-ylamino)-thiazol-5-yl]-propenone 3 and 4-(2-{1-(2-fluorophenyl)-3-[4-methyl-2-(pyridin-2-ylamino)-thiazol-5-yl]-3-oxopropylsulfanyl}-acetylamino)-benzoic acid ethyl ester 4 was revealed. The IC50 of the compound 3 in HL-60 cells of the acute human promyelocytic leukemia was 0.57 µM, while in the pseudo-normal human cell lines, the IC50 of this compound was >50 µM, which suggests that the compounds 3 and 4 might be perspective anticancer agents. The detected selectivity of the derivatives 3 and 4 for cancer cell lines inspired us to study the mechanisms of their cytotoxic action. It was shown that preincubation of tumor cells with Fluzaparib (inhibitor of PARP1) reduced the cytotoxic activity of the derivatives 3 and 4 by more than twice. The ability of these compounds to affect DNA nativity and cause changes in nucleus morphology allows for the suggestion that the mechanism of action of the novel pyridine-thiazole derivatives might be related to inducing the genetic instability in tumor cells.

Design, Synthesis and In Vitro Anticancer Activity of Benzo[c]chromen-6-one -linked 1,2,3-Triazole

Background:

The 1,2,3-triazole hybrids and conjugates containing natural or related compounds motif demonstrate diverse biological activities, including anticancer, antimicrobial, anti-tubercular, antiviral, antidiabetic, antimalarial, anti-leishmanial, and neuroprotective ones. Among a wide range of pharmacological applications, considerable attention is paid to the study of anticancer activity. In anticancer research, combining of 1,2,3-triazoles with other motifs, previously demonstrating antiproliferative activity into one hybrid molecule, is a common strategy for the creation of new bioactive molecules. The CuAAC (copper-catalyzed azide–alkyne cycloaddition) is a very convenient reaction for the rapid construction of drug-like 1,2,3-triazoles at room temperature in a short time.

Methods:

Based on the pharmacophore strategy, a virtual combinatorial library of benzo[c]chromen-6-one -linked 1,2,3-triazole derivatives was designed and lead-likeness and molecular analysis were performed. Selected compounds were synthesized via CuAAC click reaction and the chemical structures of all new 1,2,3-triazole hybrids were proved by 1H, 13C NMR, MS and elemental analyses. Their anti-cancer activity in the human cancer cell lines was evaluated using the MTT assay.

Results:

A virtual in silico screening of novel benzo[c]chromen-6-one -linked 1,2,3-triazoles was carried out in order to discover potential antitumor agents. The synthesis of promising compounds was carried out via СuAAC reaction, and their antineoplastic action was studied on human tumor cells of HL-60, HCT116, HCT116 p53-/-, Skov3, U251, MDA231 lines. Their cytotoxic effect towards pseudo-normal human cells of HaCaT line was also evaluated. 2-((1H-1,2,3-triazol-4-yl)methoxy)-6H-benzo[c]chromen-6-one (4c) with pyridin-3-yl substituent demonstrated the highest antiproliferative action in vitro (IC50 79.5 μM) towards human leukemia cells of HL-60 line, while all tested compounds at >100 μM concentration were tolerant for non-tumor human keratinocytes of HaCaT line.

Conclusion:

A novel benzo[c]chromen-6-one -linked 1,2,3-triazoles exhibiting promising in vitro anti-cancer activity and low toxicity were designed. This study suggests new scaffolds for the development of anti-cancer drugs, which could be easily further optimized via the convenient synthetic procedure.