Investigation of Anticancer Properties of Newly Synthesized Pyridazine-Based Inhibitors in Mouse and Human Breast Cancer Cell Line

Background: Breast cancer is the most common cancer among women. Although doxorubicin (DOX) is widely used in its treatment, its dose-dependent toxicity and the development of drug resistance reduce its therapeutic efficacy. Therefore, this study aims to identify a novel anticancer agent that is more effective than DOX, inhibits cancer cell growth, and is less toxic to healthy cells. Methods: The cytotoxic effects of DOX and 2S-series molecules were evaluated on human (MDA-MB-231) and mouse (4T1) TNBC breast cancer cell lines and healthy breast epithelial (hTERT) cells using MTT assays at 48 and 72 h to screen functional similarities and possible differences upon drug/inhibitor treatment. Apoptosis and cell cycle analysis were analyzed by flow cytometry. Gene expression profiles were assessed by qPCR, and binding interactions with Hsp90 were examined via molecular docking. Results: 2S-5 exhibited IC50 values of 6.21 mu M (MDA-MB-231) and 7.04 mu M (4T1), while 2S-13 showed IC50 values of 7.73 mu M and 8.21 mu M, respectively. Both compounds demonstrated selective cytotoxicity against cancer cells. Gene expression and pathway analysis revealed that 2S-13 modulated the PI3K-Akt, MAPK, apoptosis, and HIF-1 pathways, showing broader modulation than DOX. Conclusions: 2S-13 appears to be a promising drug candidate, particularly in the MDA-MB-231 cell line. However, the current findings are limited to in vitro models. Further in vivo studies and pharmacokinetic analyses are required to validate its therapeutic potential, assess long-term efficacy and safety, and explore its resistance profile and molecular mechanisms in more detail.