Investigating the impact of CD73 inhibition on chronic lymphocytic leukemia cells by siRNA molecule loaded nanoparticles on the cytotoxic effects of Fludarabine

Abstract

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in Western countries. Despite many advances in the treatment of various leukemias, there is still no definitive cure for CLL patients, and there is increasing resistance to chemotherapy-based treatments in these patients. Fludarabine is one of the drugs of choice in the treatment of CLL patients, which is resistant in many patients. Therefore, in this study, it was decided to increase the sensitivity of these cells to treatment with fludarabine by inhibiting the expression of CD73 molecule in leukemic cells. Materials and Methods: In this study, we used superparamagnetic iron oxide (SPION) nanoparticles loaded with siRNA to inhibit CD73 gene expression and concomitant transfer of fludarabine. Also in this study, to increase the stability and improve the performance of iron oxide nanoparticles, thiol chitosan and trimethyl chitosan were used to enclose them. The effect of combination therapy on leukemia cell survival was assessed using MTT and flow cytometry techniques and the expression of genes involved in apoptosis was assessed using real-time PCR. Results: The synthesized nanoparticles had a size of about 133 nm, with a dispersion coefficient of less than 0.3 and a zeta potential of about 25. Nanoparticles loaded with CD73 siRNA and fludarabine could effectively inhibit the expression of CD73 molecule in leukemic cells. Combination therapy was also able to significantly increase the sensitivity of leukemic cells to fludarabine, which was associated with increased Bax expression and decreased Bcl-2 expression.