Research of miR-30b in Cisplatin Resistance of Human NK/T Cell Lymphoma Lines SNK-6 and YTS Cells By Targeting CCL22

Objective: To investigate the role and mechanism of miR-30b underlying cisplatin resistance of human NK/T cell lymphoma lines SNK-6 and YTS cells. Methods: Normal NK cells and SNK-6 and YTS cells were cultured, the levels of miR-30b and CCL22 were detected by real-time PCR assay, CCL22 expression was detected by western blot analysis. Transfected with miR-30b mimics and inhibitor in SNK-6 and YTS cells respectively, and then measured the effect of cisplatin resistance in SNK-6 and YTS cells by MTT assay, the activity of caspase-3 was detected by caspase-3 kit assay, the cells apoptosis ratio was detected using flow cytometry analysis. The target relationship of miR-30b and CCL22 were determined by dual-luciferase reporter gene assay. The expressions of CCL22. Furthermore, the effect of CCL22 on cisplatin resistance and caspase-3 were also evaluated. Results: The levels of miR-30b were significantly decreased in both SNK-6 and YTS cells, but with the increase in CCL22 expression. MiR-30b mimics decreased the cells activity, down-regulated the cisplatin resistance, increased cells apoptosis ratio and caspase-3 activity. The effects of miR-30b inhibitor were contrary to the mimics. Up-regulated miR-30b significantly decreased the luciferase activity in CCL22 3'-UTR transfected NK cells, but not in Mut-CCL22 3'UTR group, suggesting that CCL22 could act as a direct target of miR-30b. The expressions of CCL22 pathway proteins were down-regulated after SNK-6 cells transfected with miR-30b mimics, while the effects were restored by overexpression of CCL22. Moreover, CCL22 overexpression also increased the cells activity and decreased caspase-3 activity when SNK-6 cells were transfected with miR-30b mimics. Conclusion: MiR-30b inhibited cisplatin resistance of human NKTCL in SNK-6 and YTS cells by targeting CCL22.