p53  Responsive Luciferase Reporter RKO Stable Cell Line is derived from human colon cancer, and stably express firefly luciferase reporter gene under the control of the p53 response element. This cell line is an ideal cellular model for monitoring the activation of p53 Pathway triggered by stimuli treatment,enforced gene expression and gene knockdown.
 
The p53 pathway plays a crucial role in effective tumor suppression because of its central function in cell cycle regulation, DNA repair, cellular senescence, and apoptosis, which can be used for potentially develop new drug therapies against cancer. Upon activation by DNA damage, oncogene activation, or hypoxia, p53 binds to its DNA recognition site on the promoter regions of the target genes and regulate the gene expression. Signosis has established p53 luciferase reporter RKO stable cell line, in which luciferase activity is specifically associated with the activity of p53. Therefore, the cell line can be used as a reporter system for monitoring the activation of p53 triggered by stimuli treatment, enforced gene expression and gene knockdown.
 
The cell line was established by transfection of p53 luciferase reporter vector along with G418 expression vector followed by G418 selection. The G418 resistant clones were subsequently screened for etoposide-induced luciferase activity. The clone with the highest fold induction (35 fold) was selected and expanded to produce this stable cell line.
 
Principle behind TF luciferase reporter. TF luciferase reporter stable cell line utilizes artificial promoter constructs to drive luciferase expression. The promoter region can consists of multiple repeats of a cis-element TF binding site, a DNA fragment from the promoter region of a known TF downstream gene, or a DNA fragment containing putative/known TF binding sites. There are several ways that a TF can be activated, such as through extracellular stimuli or through intracellular signaling pathways. Once activated, the TF translocates to the nucleus and often interacts with relevant co-factors to drive gene expression. Once luciferase is expressed, it can generate light in an enzymatic assay and the amount of light measured is positively correlated with the level of TF activation.