Piperazine is a promising scaffold for drug development due to its broad spectrum of biological activities. Based on this, the new
piperazine-containing compound
LQFM018 (2) [ethyl 4-((1-(4-chlorophenyl)-1H-pyrazol-4-yl)methyl)
piperazine-1-carboxylate] was synthetized and some biological activities investigated. In this work, we described its ability to bind aminergic receptors, antiproliferative effects as well as the
LQFM018 (2)-triggered cell death mechanisms, in K562 leukemic cells, by flow cytometric analyses. Furthermore, acute oral systemic toxicity and potential myelotoxicity assessments of
LQFM018 (2) were carried out.
LQFM018 (2) was originally obtained by molecular simplification from LASSBio579 (1), an analogue compound of
clozapine, with 33% of global yield. Binding profile assay to aminergic receptors showed that
LQFM018 (2) has affinity for the
dopamine D4 receptor (Ki = 0.26 μM). Moreover, it showed cytotoxicity in K562 cells, in a concentration and time-dependent manner; IC50 values obtained were 399, 242 and 119 μM for
trypan blue assay and 427, 259 and 50 μM for MTT method at 24, 48 or 72 h, respectively. This compound (427 μM) also promoted increase in LDH release and cell cycle arrest in G2/M phase. Furthermore, it triggered necrotic morphologies in K562 cells associated with intense cell membrane
rupture as confirmed by
Annexin V/
propidium iodide double-staining.
LQFM018 (2) also triggered mitochondrial disturb through loss of ΔΨm associated with increase of ROS production. No significant accumulation of cytosolic
cytochrome c was verified in treated cells. Furthermore, it was verified an increase of expression of TNF-R1 and
mRNA levels of CYLD with no involviment in
caspase-3 and -8 activation and NF-κB in K562 cells.
LQFM018 (2) showed in vitro myelotoxicity potential, but it was orally well tolerated and classified as UN GHS category 5 (LD50 > 2000-5000 mg/Kg). Thus,
LQFM018 (2) seems to have a non-selective action considering hematopoietic cells. In conclusion, it is suggested
LQFM018 (2) promotes cell death in K562 cells via necroptotic signaling, probably with involvement of
dopamine D4 receptor. These findings open new perspectives in
cancer therapy by use of necroptosis inducing agents as a strategy of reverse
cancer cell chemoresistance.