Evaluation of toxicity and apoptotic effects of copper nanoparticles in combination with imatinib on chronic myeloid leukemia cells

Imatinib, a first-generation tyrosine kinase inhibitor, is the mainstay of treatment for chronic myeloid leukemia (CML). However, long-term use can lead to cellular resistance, highlighting the need for more effective therapeutic strategies. This study investigated the cytotoxic and apoptotic effects of the combination of imatinib with copper nanoparticles (CuNPs) on the K562 cell line. K562 cells were treated with imatinib (optimal dose 0.5 µM) and non-toxic CuNPs (0.005 mg/mL), as single agents and in combination, in nine experimental groups. Cell survival was measured by MTT assay, intracellular H₂O₂ levels were measured as an indicator of oxidative stress, and the expression of apoptosis and tumor-related genes (Bax, Bcl-2, MMP2, MMP9, and IL-1β) was examined using real-time PCR. The CuNPs were spherical with an average size of approximately 50 nm. Both imatinib and CuNPs dose-dependently decreased cell survival, while their combination produced a significant cytotoxic effect even at suboptimal doses of the drug. The combination treatment resulted in a significant increase in intracellular H₂O₂ levels, indicating increased oxidative stress. Gene expression analysis revealed an increase in the pro-apoptotic gene Bax and a decrease in the anti-apoptotic genes Bcl-2 as well as MMP2, MMP9, and IL-1β, indicating synergistic induction of apoptosis and regulation of tumor-related pathways. The combination of imatinib and CuNPs produces enhanced cytotoxic and apoptotic effects in K562 cells, even at lower drug doses, indicating that CuNPs can be used as an effective adjuvant to enhance the efficacy of imatinib and delay the development of resistance in the treatment of CML.