Zübeyir Elmazoğlu, Erva Özkan
Anatolian Current Medical Journal - 2025;7(6):925-932
Aims: Venetoclax is a selective Bcl-2 inhibitor small molecule, approved by FDA for acute myeloid and chronic lymphocytic leukemia. Despite the promising results in hematological malignancies, its therapeutic potential in lung cancer remains unclear. In the present study, the effect of conventional chemotherapeutics, etoposide and cisplatin, in combination with venetoclax was investigated along with the underlying mechanisms in lung cancer cells. Methods: Human non-small cell lung cancer cells (A549) were administered with cisplatin and etoposide either as single agents or in combination with venetoclax (8 µM), and the cell viability was determined with MTT assay. The acquired cytotoxicity was compared with L929 normal cells. ROS generation was visualized by confocal microscopy in the presence or absence of antioxidants (N-acetylcysteine, mannitol) and ferroptosis inhibitors (deferoxamine, ferrostatin-1). Furthermore, labile iron pool and lysosomal lipid were detected with Hoechst/Calcein-AM/Neutral red triple staining. Lipid peroxidation was determined with malondialdehyde assay. The mRNA expressions of DNA damage marker H2AX and ferroptotic marker transferrin were evaluated with RT-qPCR. Results: Results indicated that venetoclax (8 µM) sensitizes A549 cells to etoposide (p<0.001) while having no significant impact on cisplatin activity (p>0.05). Further analyses demonstrated that co-treatment of etoposide and venetoclax significantly increased ROS generation, which was inhibited by ferroptosis inhibitors (p<0.001). Additionally, imaging analyses revealed that both labile iron pool and lysosomal lipid increase following etoposide-venetoclax co-treatment. Gene expression analyses indicated that H2AX and transferrin were both significantly upregulated in co-treated groups (p<0.05). Conclusion: This study demonstrated for the first time that venetoclax sensitizes lung cancer cells to etoposide via ferroptotic pathways and DNA damage.
