Figure 3.

Repressive effect by E-box elements in RCC23+3. One or three copies of synthetic E-box sequence were inserted downstream of the hTERT promoter in the construct pBT-255 to make the construct pBT-255–2DEB or pBT-255–4DEB, respectively (total number of downstream E-box elements is shown in parentheses). As in Figure 2, the promoter activity of each construct in RCC23 or RCC23+3 is expressed as luciferase activity relative to the pBT-255 in RCC23.