Abstract: Objective:Use the miR-1247-5p mimics which can over-expression miR-1247-5p and explore its targeted effects on Smad2 which is a key protein in TGF-? signaling pathway.Methods: Use the miR-1247-5p mimics and miR-1247-5p inhibitors Synthesized by the company.Based on chemical technology to synthetic stem-loop structure RNA of Smad2 3'-UTR which is complementary to miR-1247-5p,and cloned it into the linearized Report plasmid which was digested by restriction enzyme,then sequenced,the positive recombinants were transfected into HEK-293 T cells;use the relative luciferase activity test,and Western blot test to validate the targeted regulatory relationship between miR-1247-5p and Smad2 3'-UTR. Results: The recombinant plasmid of Report-Smad2-3'UTR were constructed successfully,and Western blot test confirmed that the over-expression of miR-1247-5p suppressed the expression level of Smad2 protein significantly(P<0.05);suppression of miR-1247-5p expression increased the expression level of Smad2 protein significantly(P<0.05).Conclusion:miR-1247-5p can directly target on the gene expression of Smad2.It is regulated at the protein level,construct the foundation of miRNA for regulation of the further research on signaling pathways.

Key words: miR-1247-5p, TGF-? signaling pathway, Smad2 gene, tumour