Combined Cyclin D1 And Bcl-xL Gene Therapy Attenuated Cell Growth And Promoted Cell Apoptosis In Non-small-cell Lung Cancer

Objectives: To determine combined Cyclin D1 and Bcl-xL's potential feasibility as a therapeutic target, we constructed a recombinant plasmid pcDNA6.2-GW/EmGFP-miR that expressed a CMV promoter-driven microRNA targeting Cyclin D1 (Cyclin D1 miRNA), Bcl-xL (Bcl-xL miRNA) and these two genes (Cyclin D1-Bcl-xL miRNA). Then the vector's ability to induce RNA interference in vitro and alter apoptosis induction in lung cancer was assessed.Methods: Four groups was used: the group of blank control (untreated cells), Cyclin D1 miRNA, Bcl-xL miRNA and Cyclin D1-Bcl-xL miRNA (transfected cells). The cell lines were used A549 and NCI-H441. The levels of mRNA and protein of Bcl-xL or Cylin D1 were detected by RT-PCR and Western blot. Apoptosis and proliferation of lung cancer cells were evaluated by dimethylthiazol-diphenyltetrazolium bromide (MTT), cell count and flow cytometry.Results: Our results suggested that the recombinant plasmid pcDNA6.2-GW/EmGFP-miR can adequately mediated RNAi in A549 and NCI-H441 cells. The expressions'levels of mRNA and protein in the groups Cyclin D1 miRNA, Bcl-xL miRNA and Cyclin D1-Bcl-xL miRNA (stable transfectants) were significantly reduced compared to untreated cells (P<0.05). There was no statistical difference in the three interventional groups (P>0.05). The cell inhibition rate and apoptosis in the three groups were increased (P<0.05). Combined interference of two genes had higher cell inhibition rate and cell apoptosis than a single one (P<0.05).Conclusions: The molecular targeting in repression of Cyclin D1 and Bcl-xL genes in combination as a therapeutic strategy for human malignancies.