Chemical synthesis, bioinformatics and antiproliferative studies of novel pyrimidin-4-yl-1H-pyrazole derivatives in chronic myeloid cancer cells

A series of novel methyl-1-(2-((3,5-dimethylphenyl)amino)pyrimidin-4-yl)-1H-pyrazole derivatives were synthesized, characterized through ¹H and ¹³C NMR and mass spectroscopic techniques and evaluated for their in silico and in vitro antiproliferative activity against leukemia cancer cells sensitive (K562) or resistant to imatinib (K562-IM). Among the studied compounds, only compound 5, with a methyl alcohol at the 4-position of pyrazole ring, and compound 6, with a methyl carboxamide at the 4-position of pyrazole ring, induced a cytotoxic response in both the CML cell lines. Despite its higher cytotoxicity in both cell line, compound 6 was also highly cytotoxic in primary normal human fibroblasts. In contrary, the high cytotoxicity of compound 5 towards both IM sensitive and resistant cell lines (K562 and K562-IM, respectively) and its lower or no effect in primary normal cells (IC 50 higher than 50 µM), indicates that this compound is suitable for further biological studies. Further, the docking score, hydrogen bond interactions, RMSD, and binding free energy also identified compound 5 as the most balanced and promising candidate by demonstrating a strong and stable binding profile with low RMSD, adequate hydrogen bonding, and favorable binding free energy. On the other hand, BOILED-Egg analysis results highlight that the compounds possess good absorption characteristics and, except for compound 5, demonstrate limited risk of efflux-mediated resistance. Indeed, when compound 5 was combined with IM in K562-IM resistant cells, a higher decrease of cell viability was observed when compared to IM alone, suggesting one more time that this pyrimidine derivative is suitable for CML therapeutics alone or in combination with IM (in resistant patients) or be used as basis for the design of new anti-cancer agents.