Akademik Veri Yönetim Sistemi
Tezin Türü: Doktora
Tezin Yürütüldüğü Kurum: Ankara Üniversitesi, Sağlık Bilimleri Enstitüsü, Türkiye
Tezin Onay Tarihi: 2025
Tezin Dili: Türkçe
Öğrenci: AL KASSIM HASSAN MOHAMMED
Danışman: Zeynep Alagöz
Özet:
This study reported
the synthesis of 21 original retinoid-benzimidazole derivatives bearing
alkylsulfonyl moiety designated as AZ1-21. The chemical synthesis
comprises of 9-step reactions split into two segments. In the first segment,
2,5-dimethyl-2,5-hexanediol as the starting material sequentially underwent
chlorination, Friedel-Craft’s alkylation, oxidation and salt formation. In the
second segment, 4-chlorobenzenesulfonyl chloride sequentially underwent
alkylation, nitration, substitution and hydrogenation to give ortho-phenylenediamine
derivative. The final intermediates in both segments were condensed together to
form the target compounds. All reactions were monitored by TLC until
completion, and the synthesized compounds were purified by crystallization or
column chromatography, and their melting points were determined. Furthermore,
structural elucidation was carried out electronspray ionization mass
spectroscopy (ESI-MS), 1H NMR and 13C NMR accordingly.
The AZ compounds were tested for their in vitro antiproliferative
activity against MCF-7 breast cancer cells via MTT and xCELLigence assays to
determine their effective doses . Three compounds – AZ1, AZ8 and AZ14
displayed the most potent activity at IC50 of 31.49 µM, 43.19 µM and 33.13 µM respectively in comparison to
standard drug ATRA (202 µM). These compounds
were further evaluated for mechanistic studies via apoptosis assay (cell death),
reactive oxygen species (ROS) and gene expression analyses at their IC50
doses. Flow cytometry analyses after annexin V-FITC/PI staining showed that
ATRA, AZ1, AZ8 and AZ14 induced apoptosis (sum of early
and late apoptotic cells) in MCF-7 cells by 23.79% (p<0.01), 29.16%
(p<0.01), 28.46% (p<0.01) and 22.82% (p<0.05), respectively.
Elsewhere, ROS ratio in MCF-7 cells increased by 7.90% in ATRA treated cells (p<0.05),
increased by 4.99% in AZ1 treated cells (p<0.05), increased by 2.47%
in AZ8 treated cells but decreased by 9.10% in AZ14 treated cells.
Changes in gene expression levels in 10 genes (BIRC5, CCNE1, CCND1, P53,
BCL-2, BAX, PRDX1, SOD1, GPX4 and CAT) involved in cell cycle,
apoptosis and oxidative stress pathway and intracellular ROS activity levels
were determined. Although AZ1 acted via ROS, AZ8 acted via
apoptosis and AZ14 via ROS, the decrease in GPX4 gene expression
level indicates that cell death may be associated with other pathways,
especially ferroptosis. In silico molecular docking simulations showed compound
AZ8 docked well to the active site of the RARb and RARg proteins and yield
key interractions that could play key role in their antiproliferative activity
in MCF-7 cells. ADME predictions in terms of Lipinski rule was favourable for AZ1
and AZ8 to be considered potential drug candidates.