Abstract: Objective: To determine the effects of miR-34a-5p on proliferation of HaCaT human keratinocytes and expressions of Notch1 mRNA. Methods: HaCaT cells were cultured in vitro and transfection concentration were optimized. And than, the cells were divided into 4 groups: miR-34a-5p minic group (minic), negative control group (NC)，miR-34a-5p inhibitor group (inhibitor) and inhibitor negative control group (inhibitor NC). Cell proliferation was detected by MTT assay. The expression of Notch1 mRNA was detected by RT-qPCR. Results: After transfected for 48 hours, the proliferation vitality of HaCaT cells and the level of Notch1 in NC group were 20.7% and 1.0 ± 0.06 respectively, those in minic group were 39.7% and 2.78 ± 1.30, those in inhibitor group was 15.7% and 0.37 ± 0.46. There were significant differences in the proliferation vitality of HaCaT cells and the level of Notch1 between minic group, inhibitor group and NC group (Ps＜0.05). Conclusion: miR-34a can promote the proliferation of HaCaT cells, which may be related to the upregulation of Notch1 mRNA.

Key words: psoriasis, miR-34a, HaCaT cell, Notch1