[MiR-30b Regulates the Cisplatin-Resistance of Human NK/T Cell Lypnphoma Cell Lines SNK-6 and YTS by Targeting the CCL22].

OBJECTIVE: To explore the effect and mechanism of miR-30b on cisplatin-resistance of human NK/T cell lymphoma lines SNK-6 and YTS cells. METHODS: Normal NK cells, SNK-6 and YTS cells were cultured, the expression levels of miR-30b and macrophage-derived chemokine (CCL22) were detected by real-time PCR assay, and the CCL22 expression was detected by Western blot. The SNK-6 and YTS cells were transfected with miR-30b mimics and inhibitor respectively, then the effect of cisplatin resistance in SNK-6 and YTS cells was measured by MTT assay, the activity of caspase-3 was detected by caspase-3 assay kit, and the cell apoptosis was analyzed by flow cytometry. Dual-luciferase reporter gene assay was used to determine the targeting relationship between miR-30b and CCL22. Furthermore, the effect of CCL22 on cisplatin-resistance and caspase-3 actirity was also evaluated. RESULTS: Compared with the normal NK cells, the expression levels of miR-30b significantly decreased in both SNK-6 and YTS cells (P＜0.01), but CCL22 mRNA expression increase in both cells (P＜0.01). MiR-30b mimics decreased the cell activity (P＜0.05), down-regulated the cisplatin-resistance (P＜0.05), and increased cell apoptosis and caspase-3 activity (P＜0.05). The effects of miR-30b inhibitor were contrary to the mimics. Up-regulation of miR-30b expression 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 (P＜0.05), while this effect was restored by overexpression of CCL22. Moreover, CCL22 overexpression also increased the cell activity and decreased caspase-3 activity when SNK-6 cells were transfected with miR-30b mimics. CONCLUSION: MiR-30b inhibits cisplatin-resistance of human NK/TCL SNK-6 and YTS cells by targeting CCL22.