Research Of The Tumor Suppressor Gene PTEN In A549 Cells By Regulation Of MicroRNA-21

Objective : To construct eukaryotic expression plasmid which contains microRNA-21, and to investigate the regulatory of microRNA-21 on the expression of the tumor suppressor gene PTEN in A549.Methods: microRNA-21 was synthesized and inserted into plasmid pGenesil-1 to construct the eukaryotic expression vector. Recombinant plasmid was transfected into A549 cells. RT-PCR and Western blot were used to detect the expression of mRNA and protein levels of PTEN gene.Results:After identification by endonuclease digesting and DNA sequencing, the recombinant plasmid was constructed successfully; the rate of PTEN/GAPDH is 0.2187±0.022 in control, the rate is 0.2200±0.027 in A549 cell transfected with empty vectors, and 0.2233±0.018 in A549 cell stably transfected with recombinant plasmid. Compared with control and A549 transfected with empty vectors, mRNA level of PTEN gene in A549 cell stably transfected with recombinant plasmid had no significant difference (P>0.05); The rate of PTEN/GAPDH is 0.2433±0.0425 in control, the rate is 0.2640±0.0275 in A549 cell transfected with empty vectors, and 0.1067±0.0421 in A549 cell stably transfected with recombinant plasmid. (P<0.05).Conclusion: mRNA level of PTEN gene in A549 cell had no significant change after stably transfected with recombinant plasmid, but the result of Western blot showed that the protein level of PTEN gene changed after stable transfection. microRNA-21 may be control PTEN gene expression in A549 cells at translation level.