Provided is a small activating RNA (saRNA) and an application thereof in medicines for activating or up-regulating target gene expression, the saRNA being composed of a first oligonucleotide chain containing 17 to 30 nucleotides and a second oligonucleotide chain containing 17 to 30 nucleotides. The first oligonucleotide chain comprises a series at least 15 nucleotides in length having bases complementary to those of the second oligonucleotide chain. There exists 75% or greater homology or complementarity between the first or second oligonucleotide chain and any continuous segment 15-30 nucleotides in length of the promoter of the target gene. One end of a double strand formed by the first and second oligonucleotide chains is a flat end, and the other end thereof may form a 1-4 nucleotide protruding end at the end of the first oligonucleotide chain or of the second oligonucleotide chain.

Novel small activating RNA

Objective To construct the small-molecule double-stranded RNA (dsRNA) expression vector plasmid,and to investigate its activation ability of the expression of cell cycle repressor protein p21WAF1/CIP1(p21) in human prostate cancer cell line PC-3 in vitro.Methods Synthetic the sequence-specific corresponding DNA fragments of the promoter with the p21 gene,as well as the same length of random DNA fragments,by means of the recombinant DNA technology to construct these fragments into the eukaryotic expression plasmids pGenesil-1,constructed with the purpose of the expression of dsRNA fragments plasmid vectors (dsRNAp21-pGenesil-1) and the random fragments of the control dsRNA expression vectors (dsRNACon-pGenesil-1).The dsRNAp21-pGenesil-1 (experimental group),dsRNACon-pGenesil-1 (negative control group) and a blank plasmid pGenesil-1 (control group) were transfected into human prostate cancer cell line PC-3 in vitro respectively with lipofectamine reagent,and transfection efficency was detected by laser scanning confocal microscope.Immunohistochemistry and reverse transcription-PCR were performed to examine the difference expression level of p21 in each group.Results These dsRNAp21-pGenesil-1 and the dsRNACon-pGenesil-1 eukaryotic cell expression vectors were successfully constructed.For each of the groups of plasmids transfected into PC-3 cells,p21 gene expression in the experimental group significantly increased,while there was no significant difference between the negative control group and the blank control group.Conclusions The dsRNAp21-pGenesil-1 express dsRNA molecule successfully,and active the level of expression of p21 mRNA and protein,and provide an effective tool for studying the activation effect of dsRNA.

YE Zhang-qu

Papers

Construction of dsRNA expression vector and research of RNA activation