Skip to main content
. 2016 Feb 1;7(16):21272–21286. doi: 10.18632/oncotarget.7114

Figure 3. Transcriptional activity of the minimal CALB2 promoter is proportional to calretinin expression.

Figure 3

Transcriptional activity of different promoter constructs was assessed by transient transfection and dual luciferase assay using pTK-RL as an internal control. (A) 5′-deletion constructs of the CALB2 promoter engineered in the pGL3-basic (pGL3-B) luciferase reporter plasmid. Lines represent CALB2 promoter fragment; the name and the size are indicated by nucleotide position upstream (−) or downstream (+) relative to the transcription start site (+1). (B) CALB2 promoter activity in ONE58, SPC111, ZL55 and NCI-H226 cells, which express different levels of calretinin. To allow for comparison of the absolute promoter activity between the cell lines, Firefly light units were multiplied by a correction factor that compensates for differences in the transfection efficacy. The correction factor was based upon the Renilla Light Units (ReLU) of the internal control, pTK-RL, and was calculated by dividing the mean ONE58 ReLU by the mean of ZL55, SPC111 and H226 ReLU for each construct. Mean ± SD, n = 3. (C) Relative mRNA abundance is plotted versus the relative Firefly light units reflecting absolute −161/+80bp CALB2 activity for the indicated cell lines.