Oxaprozin-Based Amide Derivatives as Multifunctional Agents: Synthesis, Characterization, and Comprehensive...

Background/Objectives: Inflammation plays a role at multiple levels, contributing to tumorigenesis, cellular proliferation, cell survival, and metastasis. The established link between chronic inflammation and tumor development has shifted the therapeutic focus toward nonsteroidal anti-inflammatory drugs, which exert their effects primarily through cyclooxygenase inhibition. Methods: In the present study, the antitumor potential of novel synthesized oxaprozin derivatives was evaluated using the MTT assay. The immunomodulatory effects of the selected derivative were determined in vitro by measuring cytokine concentrations and performing flow cytometry. To investigate the inhibitory capacity of these derivatives against cyclooxygenase enzymes, an in vitro inhibition assay was conducted using fluorometric screening kits, followed by in silico validation. Results: All tested tumor cell lines exhibited sensitivity to compound 1, which demonstrated the lowest cytotoxic effect against non-cancerous mMSCs and MRC-5 cells. This compound can effectively target tumor cells, inducing potent apoptosis in 4T1 breast cancer cells through a strategic shift in the Bax/Bcl-2 balance and the downregulation of the oncogenic driver Bcl-6. Although the synthesized oxaprozin derivatives showed moderate affinity for COX-1, none of the newly synthesized compounds achieved more than 50% inhibition against COX-2 at a concentration of 100 μM. Consistently, in silico procedures validated the results of the in vitro COX inhibition assay. Conclusions: The findings of this study indicate that compound 1 has the ability to modulate immune responses under stimulated conditions, and its potent antitumor activity may not be directly related to cyclooxygenase inhibition, suggesting the involvement of COX-independent pathways.