TCF responsive element
AssigneeCobra Therapeutics Limited
InventorsLawrence S. Young, Kai S. Lipinski, Christopher J. Wrighton
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Abstract
Disclosed are DNA elements and constructs useful for obtaining tumour-selective gene expression in tumours having a mutated β-catenin/APC pathway. In particular, the use of these constructs to express genes encoding therapeutic proteins in colorectal cancer cells is described. The constructs comprise multiple repeats of a TCF-binding element operably linked to a promoter. By means of such a construct, tumour cell-specific expression of a prodrug-converting enzyme such as nitroreductase may be achieved. Coupled with systemic administration of a suitable prodrug, such as CB1954, selective killing of such tumour cells can be demonstrated.
Claims30
A nucleic acid construct comprising:
- a T-cell factor (TCF) response element comprising:
- at least one TCF binding element having the sequence CTTTGNN,
- wherein N is A or T;
- a promoter, and
- an expressible therapeutic gene operably linked to the TCF response element,
- wherein the TCF response element enables inducible expression of the operably linked therapeutic gene.
A nucleic acid construct comprising:
- a TCF response element comprising:
- at least one TCF binding element having the sequence CTTTGNN,
- wherein N is A or T;
- a promoter, and
- an expressible therapeutic gene operably linked to the TCF response element,
- wherein the TCF response element enables inducible expression of the operably linked therapeutic gene selected from the group consisting of toxins, prodrug activating enzymes, immunomodulatory agents, tumor suppressor genes, and apoptotic genes.
A nucleic acid construct comprising:
- a TCF response element comprising:
- at least 5 TCF binding elements having the sequence CTTTGNN,
- wherein N is A or T;
- a promoter, and
- an expressible therapeutic gene operably linked to the TCF response element, wherein the TCF response element enables inducible expression of the operably linked therapeutic gene.
A nucleic acid construct comprising:
- a TCF response element comprising:
- at least two TCF binding elements having the sequence CTTTGNN,
- wherein N is A or T;
- a promoter, and
- an expressible therapeutic gene operably linked to the TCF response element,
- wherein the TCF response element enables inducible expression of the operably linked therapeutic gene, and wherein the TCF binding elements are separated from each other by between 3 and 20 nucleotides,
A nucleic acid construct comprising:
- a TCF response element comprising:
- at least one TCF binding element having the sequence CTTTGNN,
- wherein N is A or T;
- a promoter, and
- an expressible therapeutic gene operably linked to the TCF response element,
- wherein the TCF response element enables inducible expression of the operably linked therapeutic gene, and wherein the TCF binding element closest to the promoter is between 140 and 10 nucleotides from the TATA box of the promoter.
A TCF response element comprising:
- at least five TCF binding elements;
- and
- a promoter sequence,
- wherein the TCF response element when operably linked to an expressible gene gives inducible expression of the operably linked gene.
A method of identifying candidate drugs for use in the treatment of cancers associated with the deregulation of the Wnt signalling pathway comprising the steps of contacting a TCF reporter construct comprising a TCF response element comprising
- at least five TCF binding elements;
- a promoter sequence, and
- a reporter gene,
- wherein the TCF response element when operably linked to the reporter gene gives inducible expression of the reporter gene, with a test compound under conditions in which the reporter gene is transcribed;
- and measuring the transcription of the reporter gene;
- wherein a test compound which inhibits transcription of the reporter gene is a candidate drug for cancer treatment.
Dependencies are inferred from the claim text.