Construction of MCF-7 and SK-BR-3 cell strains expressing NNMT stably.

<p>Real-Time RT-PCR analysis (A, C) and Western blot (B, D) were used to analyze NNMT expression in MCF-7, MCF-7/Vector, MCF-7/NNMT-1, MCF-7/NNMT-2, SK-BR-3, SK-BR-3/Vector, SK-BR-3/NNMT-1 and SK-BR-3/NNMT-2. GAPDH was used as an internal control. (A, B) NNMT mRNA and protein levels were increased significantly after transfected with pcDNA3.1/NNMT in MCF-7 cells compared to the MCF-7/Vector. (C, D) NNMT mRNA and protein levels were increased significantly after transfected with pcDNA3.1/NNMT in SK-BR-3 cells compared to the SK-BR-3/Vector. The differences between cells transfected with pcDNA3.1 and wild type cells were not significant both in MCF-7 cells and SK-BR-3 cells. (B) and (D) shows the protein quantification of the western blot results, respectively. The mRNA and protein levels were normalized to GAPDH level and are shown relative to the control groups (normalized as 1). Values in (B, D) are expressed as means ± SD of four independent experiments. * <i>P</i> <0.05 vs. control group.