A New p53 Cell-Based Assay

Summary Harvard researchers developed a reliable, high-throughput screening assay to identify activators and inhibitors of p53. This cell-based luminescence assay measures the level of a reporter gene product under the control of a promoter containing a p53-binding site.

P53 is a transcription factor that can activate multiple genes involved in cell cycle regulation, DNA repair and programmed cell-death. It is often described as the "gatekeeper" of cellular integrity and plays a central role in tumor suppression. It is the most frequently mutated protein in human cancers.

This assay features a triple read-out system where:
-Two cell lines express different reporter genes under the control of the same p53- binding promoter. -A third cell line expresses a third reporter gene under the control of a constitutive promoter.


Figure 1: Three reporter cell-lines in one assay well: the screen identifies compounds that specifically affect p-53-dependant firefly luciferase (FL) and secreted alkaline phosphatase (SEAP) expression without affecting CMV promoter-driven renilla luciferase (RL) expression.

This inventive cell-based assay:
- Allows to screen compounds under physiological conditions;
- Identifies chemicals that specifically affect p53 expression;
- Controls non-specific effects;
- Eliminates the need for multiple screenings;
- Allows high-throughput screens.

Harvard's intellectual property portfolio includes the following patent: US 6,569,506 issued July 22, 2003.

Applications Cell-based assays identify cell-permeable molecules active within a physiological environment, in contrast to biochemical assays in which a compound is added to a purified or partially purified cell-extract. However, one major drawback of the currently available cell-based assay systems is the high false-positive rate resulting from non-specific effects within the cells. For Further Information Please Contact the Director of Business Development Katie Gordon Email: [email protected] Telephone: (617) 432-0920

Inventor(s): Kim, Tae Kook

Type of Offer: Licensing



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