FN-1501 Inhibits Diffuse Large B-Cell Lymphoma Tumor Growth by Inducing Cell Cycle Arrest and Apoptosis

Background: Due to its high degree of aggressiveness, diffuse large B-cell lymphoma (DLBCL) presents a treatment challenge because 30% to 50% of patients experience resistance or relapse following standard chemotherapy. FN-1501 is an effective inhibitor of cyclin-dependent kinases and Fms-like receptor tyrosine kinase 3. Objective: This study aimed to examine the anti-tumor impact of FN-1501 on DLBCL and clarify its molecular mechanism. Methods: This study used the cell counting kit-8 assay to evaluate cell proliferation, along with western blotting and flow cytometry to analyze cell cycle progression and apoptosis influenced by FN-1501 in vitro. Afterward, the effectiveness of FN-1501 was evaluated in vivo utilizing the xenograft tumor model. In addition, we identified the potential signaling pathways and performed rescue studies using western blotting and flow cytometry. Results: We found that FN-1501 inhibited cell proliferation and induced cell cycle arrest and apoptosis in DLBCL cells in vitro. Its anti-proliferative effects were shown to be time- and dose-dependent. The effect on cell cycle progression resulted in G1/S phase arrest, and the apoptosis induction was found to be caspase-dependent. FN-1501 treatment also reduced tumor volumes and weights and was associated with a prolonged progressionfree survival in vivo. Mechanistically, the MAPK and PI3K/AKT/mTOR pathways were significantly inhibited by FN-1501. Additional pathway inhibitors examination reinforced that FN-1501 may regulate cell cycle arrest and apoptosis through these pathways. Conclusion: FN-1501 shows promising anti-tumor activity against DLBCL in vivo and in vitro, suggesting its potential as a new therapeutic option for patients with refractory or relapsed DLBCL.