Extracellular vesicle-mediated regulation of imatinib resistance in chronic myeloid leukemia via the miR-629-5p/SENP2/PI3K/AKT/mTOR axis.

Background: Imatinib (IM) is the primary treatment for patients with chronic-phase CML (CML-CP). However, an increasing number of CML-CP patients have developed resistance to IM. Our study aims to explore the expression of miR-629-5p in extracellular vesicles (EVs) from both IM-sensitive (K562) and resistant (K562-Re) CML cell lines and to investigate the impact of regulating miR-629-5p expression on the biological characteristics of K562 and K562-Re cells.

Methods: Assess miR-629-5p expression levels in IM-sensitive and resistant CML cell lines. Separate EVs and verify it. EVs from K562-Re cells were co-cultured with K562 cells to detect the expression level of miR-629-5p. Target genes of miR-629-5p were determined and validated through luciferase experiments. Examined by manipulating miR-629-5p expression in cells using transfection techniques. The expression level of phosphorylated proteins in the PI3K/AKT/mTOR signaling pathway after IM was detected in CML cell lines. In K562-Re cells, the expression level of phosphorylated protein in the PI3K/AKT/mTOR signaling pathway was detected after single transfection of miR-629-5p inhibitor and cotransfection of miR-629-5p inhibitor and siSENP2.

Results: Increasing concentrations of EVs from K562-Re cells elevated miR-629-5p expression levels. The expression levels of miR-629-5p in CML cells varied with IM concentration and influenced the biological characteristics of cells. SENP2 was identified as a target gene of miR-629-5p. Furthermore, miR-629-5p was found to modulate the SENP2/PI3K/AKT/mTOR pathway, impacting IM resistance in CML cells.

Conclusion: EVs from IM-resistant CML cells alter the expression of miR-629-5p in sensitive cells, activating the SENP2/PI3K/AKT/mTOR pathway and leading to IM resistance.