MicroRNA122 enhances the cytotoxic activity of Gemcitabine on A549 cells

Objective To investigate the effect of microRNA122 (miRNA122) on cytotoxic activity of Gemcitabine on A549 cells. Methods The expression vector of miRNA122 was transfected using liposomes, and the CCK-8 was used to test the inhibition rate of Gemcitabine on non-small cell lung cancer A549 cells, then the score of IC₅₀was calculated. The effect of Gemcitabine on non-small cell lung cancer A549 cells was tested by colony-forming assay, and the apoptosis rate of A549 cells induced by Gemcitabine was tested by flow cytometry-Annexin/PI experiment. Results Transfection of miRNA122 enhanced the cytotoxic activity of Gemcitabine on A549 cells with the IC₅₀values reducing from (78.6±5.25) nmol/L to (10.26±1.18) nmol/L. Moreover, transfection of miRNA122 up-regulated the apoptosis of A549 cells induced by Gemcitabine with the apoptosis rates increasing from 26.24%±1.94% to 63.30%±3.96%. The results of RT-PCR and Western Blot assays showed that the expression level of miRNA122 was up-regulated, and its targeted genes were down-regulated via transfected miRNA122. Conclusion miRNA 122 can enhance the cytotoxic activity of Gemcitabine on A549 cells.