LncRNA MALAT1 promotes cell proliferation and imatinib resistance by sponging miR-328 in chronic myelogenous leukemia

Chronic myeloid leukemia (CML) is a type of cancer that starts in certain blood-forming cells of the bone marrow. LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a well known protooncogene, has be shown to be upregulated in various tumor types, including multiple myeloma. However, the biological function of MALAT1 in CML remains has yet to be explored. This study was designed to investigate the effects of MALAT1 on the physiological processes in CML and its underlying mechanisms, which will be helpful for us to have a better understanding of CML development and progression as well as improved therapeutic method. Recombinant virus construction and infection was performed to overexpress or knockdown the expression of MALAT1. Dual luciferase reporter assay was applied to vetify the interaction between MALAT1 and miR-328. The cell viability and cell cycle were analyzed by CCK-8 assay and flow cytometry, respectively. Quantitative real time PCR and western blotting assays were used to measure the expression of genes and proteins. The expression of MALAT1 was significantly increased in CML cells compared with peripheral blood cells from health donors. Silencing of MALAT1 significantly inhibited the proliferation and arrested cell cycle of CML cells by targeting miR-328. Moreover, MALAT1 knockdown enhanced imatinib sensitivity of K562 cells, while silencing of miR-328 abolished this effect. These findings indicate that lncRNA MALAT1/miR-328 axis promotes the proliferation and imatinib resistance of CML cells, providing new perspectives for the future study of MALAT1 as a therapeutic target for CML.