Figure 2.

Transcriptional upregulation of MHC class I APM components by BGN overexpression in BGN^low/neg HER-2/neu⁺ cells. A. Relative mRNA expression levels of selected APM components in BGN^low/neg and BGN^high HER-2/neu⁺ cells. The mRNA expression levels of APM components in BGN^low/neg vs. BGN^high HER-2/neu⁺ cells were analysed by qPCR as described in Materials and Methods. The results represent the mean of 3 independent experiments. B. Western blot analysis. Protein expression was determined as described in Materials and Methods. A representative Western blot staining is presented. C. Transcriptional upregulation of APM components by BGN overexpression. The activity of selected APM promoters was determined in BGN^low/neg HER-2/neu⁺ cells, mock transfectants and two independent BGN transfectants (clones 2 and 3) as described in Materials and Methods. APM promoters were transiently co-transfected with the β-gal vector using lipofectamine in the respective cells 48 h prior to determination of the luc activity. The data were normalized to β-gal activity. The experiments were performed at least 3 times. Error bars in all panels indicate standard error. rel luc activity, relative luc activity.