Page 174 - SRPSKO DRUŠTVO ISTRAŽIVAČA RAKA

Serbian Association for Cancer Research SDIRSACR

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The ultrastructural alteration of A549 (KRASmut) and Mcf7 (KRASwt) cell lines in response to aroylacrylic
acid phenylamides treatment

Sara Stojanović , Tamara Vujatović-Velimirov , Snežana K. Bjelogrlić , Jelena Grahovac , Maja D. Vitorović-Todorović ,
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Aleksandra Korać 1
1Faculty of Biology, University of Belgrade, Belgrade, Serbia
2Military Technical Institute, Belgrade, Serbia
3Institute for Oncology and Radiology of Serbia, Belgrade, Serbia
Keywords: KRAS, aroylacrylic acid phenylamides, reactive oxygen species, mitochondria, lipid droplets

Background: KRAS mutation is the most frequent oncogenic alteration in human cancer, and it contributes to tumor
survival and resistance to therapy. Malignant cells with a KRAS mutation cope with increased oxidative stress and
maintain homeostasis by antioxidant defense mechanisms.
Material and Methods: This study was based on uncovering the cellular responses of A549 (KRASmut) and Mcf7
(KRASwt) cell lines, after 24 hours treatment with aroylacrylic acid phenylamides. The generation of reactive oxygen
species (ROS) is the primary mechanism by which aroylacrylic acid phenylamides induce cell death. Comparison of the
use of Annexin V and Propidium Iodide (Annexin V/PI) staining and ultrastructural analysis were performed.
Results: Significant differences were observed between treated cell lines. Initially, A549 cells showed greater resistance
compared to Mcf7 cells, but despite this A549 cells suffered significant cell death after 24 hours. The heterogeneity
of the cellular response between A549 and Mcf7 cells was not surprising due to the difference in their KRAS status.
Transmission electron microscopy (TEM) analysis revealed ultrastructural changes, including mitochondrial damage,
autophagy, and lipid accumulation in treated cells. The degree of mitochondrial damage was categorized into four grades
based on the size and integrity of cristae. Autophagy was observed in both cell lines, often targeting mitochondria that
were only mildly damaged. Increased lipogenesis and lipid accumulation were predominantly observed in A549 cells,
indicating their metabolic adaptability. In contrast, MCF7 cells showed lipid accumulation after treatment primarily in
necrotic cells.
Conclusions: Although the ability of A549 cells to induce lipogenesis and autophagy as protective strategies was
ultimately insufficient, as demonstrated by the high rate of apoptosis after 24 hours. These findings suggest that
KRASmut cells generate transient resistance through antioxidant defenses and lipid accumulation, delaying but not
preventing cell death. Furthermore, these results indicate different metabolic vulnerabilities between KRASmut and
KRASwt cells, highlighting the role of oxidative phosphorylation as a potential therapeutic target.

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Antimelanoma effect of mefloquine-mediated lysosomal destabilization and glucose deprivation in A375
melanoma cells

Maja Misirkić Marjanović , Ljubica Vučićević , Nevena Zogović , Gordana Tovilović Kovačević , Milica Kosić , Miloš
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Mandić , Mihajlo Bošnjak , Kristina Janjetović , Danijela Stevanović , Srđan Kesić , Vladimir Trajković , Ljubica Harhaji-
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Trajković 1
1Institute for Biological Research “Siniša Stanković” – National Institute of the Republic of Serbia, University of Belgrade, Belgrade,
Serbia
2Faculty of Medicine, University of Belgrade, Belgrade, Serbia
Keywords: apoptosis, lysosome, mefloquine, melanoma
Background: Tumor cells often exhibit enlarged lysosomes and a high reliance on glycolysis for energy production,
distinguishing them from normal cells. These features support their rapid proliferation and survival under stress.
Enlarged lysosomes are more prone to membrane destabilization, while glycolytic dependence renders tumor cells
vulnerable to metabolic disruption. Targeting these distinct traits with lysosome-disrupting agents and glucose
deprivation offers a promising therapeutic strategy. To test this theory, we exposed A375 melanoma cell line and

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