Page 62 - SDIR5 Abstract book 21 12 2021.

POSTER PRESENTATIONS

P22

Identification and validation of mechanism responsible for leukemia cell death treated with
bis-(salicylaldehyde)thiocarbohydrazone (BTCH1)

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1
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Snezana K. Bjelogrlic , Kaja Bergant , Aleksandra Bozic , Aleksandar Marinkovic , Ilija Cvijetic , Andrej
4
2
Perdih
1 National Cancer Research Center, Pasterova 14, Belgrade, Serbia
2 National Institute of Chemistry, Hajdrihova 19, Ljubljana, Slovenia
3 Academy of Applied Technical Studies, Katarine Ambrozic 3, Belgrade, Serbia
4 Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, Belgrade, Serbia
5 University of Belgrade, Faculty of Chemistry, Studentski trg 12-16, 11000 Belgrade, Serbia

Background: Methyl-2-pyridyl keton thiocarbohydrazone (MTCH1) and Salicylaldehyde
thiocarbohydrazone (MTCH2), with their two corresponding symmetrical bis-counterparts Bis-
(salicylaldehyde)thiocarbohydrazone (BTCH1) and Bis-(methyl-2-pyridyl ketone)thiocarbohydrazone
(BTCH2) were assessed for activity on acute human monocytic leukemia THP1 cells. Material and methods:
Response of THP1 cells to applied treatments was evaluated by Annexin V/PI staining, cell cycle distribution,
caspase-8 and -9 activation, and mitochondrial superoxide radicals (MSR) generation. Relaxation assay (RA),
decatenation assay (DA) on kinetoplast DNA and plasmid DNA cleavage assay (pDNAcA) were utilized to
test compounds´ ability to inhibit topoisomerase II-alpha (topo-IIα) activity. Results: All four compounds
were revealed as strong inducers of cell death through the activation of caspase-8 in cells treated with
MTCHs, and caspase-9 in cells treated with BTCHs. While both MTCHs and BTCH2 induced accumulation of
cells at the G1-to-S phase, a striking arrest at the S-to-G2 transition point was seen only in cells subjected
to BTCH1. According to MSR assay, reactive oxygen species are not responsible for DNA damage observed
in BTCH1-treated cells. RA showed that BTCH1 should be further evaluated as topo-IIα inhibitor. DA
demonstrated that BTCH1 is stronger topo-IIα inhibitor than etoposide, while the pDNAcA confirmed
BTCH1 as a catalytic topo-IIα inhibitor. Conclusion: The results of this study provide insights into the
mechanism of BTCH1 activity in leukemia model. Additional investigations are necessary to find out
whether catalytic inhibition of topo-IIα activity by BTCH1 is ATP-dependent, as well as to determine
selectivity of BTCH1 toward topo-IIα enzyme.
Keywords: topoisomerase II-alpha; thicarbohydrazone; catalytic topo II- alpha inhibitor; acute human
monocytic leukemia

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