[Effect of miR-214 on Fludarabine Resistance in Chronic Lymphocytic Leukemia]

To investigate effect and mechanism of miR-214 in fludarabine resistance of chronic lympho-cytic leukemia (CLL).

A total of 10 patients with CLL resistante to fludarabine (Flu) and 10 healthy persons admitted to Hematology Department of our hospital in August 2014 - July 2018 were selected. Expression level of miR-214 in mononuclear cells in patients with CLL and healthy persons were determined by RT-PCR. Primary CLL cells from patients with CLL were divided into normal control group (control group), negative control group (miR-214-NC group) and viral transinfection group (miR-214-ASO group). After 24 h-transfection, CLL cells were cultured with different con-centration of Flu for 48 h, then the cell proliferation and apoptosis were detected, and the levels of down-stream genes and proteins releted with PTEN and PI3K/AKT signialing pathway were determined.

The expression level of miR-214 in mononuclear cells of CLL patients significantly increased in comparison with healthy persons(P<0.05); the expression level of miR-214 in miR-214-ASO group significantly decreased (P<0.05); Absorbance in control group at Flu concentration of 3, 10 and 30 μmol/L was significantly decreased (P<0.05). Apoptosis rate in miR-214-ASO group at Flu concentration of 10 mmol/L significantly increased (P<0.05). At Flu concentration of 10 mmol/L, mRNA levels PTEN and BAD in miR-214-ASO group significantly increased (P<0.05), but mRNA levels of MDM2 and NF-κB significantly decreased (P<0.05). At Flu concentration of 10 mmol/L, protein levels of PTEN and p-BAD in miR-214-ASO group significantly increased (P<0.05), but protein levels of MDM2 and NF-κB significantly decreased (P<0.05).

Inhibition of miR-214 can enhance the sensitivity of drug-resistant CLL cells to fludarabine, which may be raleted with the promotion of cell apotosis and regulation of down-stream molecules expression of PTEN/AKT signaling pathway.