%0 Journal Article %A YUKITOSHI NAGAHARA %A KATSUHIKO NAGAHARA %T Relationship Between Structure and Antiproliferative Activity of Novel 5-amino-4-cyanopyrazole-1-formaldehydehydrazono Derivatives on HL-60RG Human Leukemia Cells %D 2017 %J Anticancer Research %P 6329-6333 %V 37 %N 11 %X Background: Pyrazole derivatives have been reported to have potent antimicrobial and anticancer activity. We recently synthesized and determined the effects of analogs, benzamidoxime derivatives, on mammalian cells and discovered that benzamidoximes had an antiproliferative effect. Here we synthesized and determined the anticancer effects of hydrazonopyrazole derivatives on a mammalian cancer cell line. Materials and Methods: We synthesized 12 hydrazonopyrazole derivatives with several constant alkyl chain length or branched chains at the side chain to investigate their anticancer cell activity, using the human myelogenous leukemia cell line HL-60RG. Results: Among all hydrazonopyrazole derivatives we synthesized, the hydrazonopyrazole derivative with a branched chain at the side chain rather than a constant alkyl chain significantly inhibited cell viability. The strongest hydrazonopyrazole derivative, 5-amino-4-cyanopyrazole-1-formaldehydehydrazono-3’-pentanal, tended to damage cells dose-dependently. This cell growth attenuation was a result of apoptosis, activating caspase-3 and fragmented DNA. Conclusion: Hydrazonopyrazole derivatives induced apoptosis of HL-60RG leukemia cells. %U https://ar.iiarjournals.org/content/anticanres/37/11/6329.full.pdf