Tumour Suppressor Protein

Abstract

We describe a polypeptide which binds and modulates the activity of a tumour suppressor polypeptide, for example p53; a nucleic acid molecule encoding said protein and screening methods which modulate the binding activity of said polypeptide for its target polypeptide(s).

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a divisional application of U.S. patent application Ser. No. 10 / 582,316 which is the U.S. National Stage of International Application No. PCT / GB2004 / 003492, filed Aug. 13, 2004 (published in English under PCT Article 21(2)), which in turn claims the benefit of Great Britain Application No. 0328690.3, filed Dec. 10, 2003 and U.S. Provisional Application No. 60 / 554,990, filed Mar. 19, 2004. The disclosure of each priority application is incorporated herein by reference in its entirety.FIELD[0002]The invention relates to a protein that binds and modulates the activity of a tumour suppressor protein, for example p53; a nucleic acid molecule encoding said protein and screening methods which modulate the binding activity of said polypeptide for its target polypeptide.BACKGROUND[0003]Tumour suppressor genes encode proteins which function to inhibit cell growth or division and are therefore important with respect to maintainin...

AI Technical Summary

Benefits of technology

[0027]Adaptations which facilitate the expression of vector encoded genes include the provision of transcription termination / polyadenylation sequences. This also includes the provision of internal ribosome entry sites (IRES) which function to maximise expression of vector encoded genes arranged in bicistronic or multi-cistronic expression cassettes.

[0043]A modified antibody, or variant antibody and reference antibody, may differ in amino acid sequence by one or more substitutions, additions, deletions, truncations which may be present in any combination. Among preferred variants are those that vary from a reference polypeptide by conservative amino acid substitutions. Such substitutions are those that substitute a given amino acid by another amino acid of like characteristics. The following non-limiting list of amino acids are considered conservative replacements (similar): a) alanine, serine, and threonine; b) glutamic acid and asparatic acid; c) asparagine and glutamine d) arginine and lysine; e) isoleucine, leucine, methionine and valine and f) phenylalanine, tyrosine and tryptophan. Most highly preferred are variants which show enhanced biological activity.

[0053]The therapeutics of the invention can be administered by any conventional route, including injection or by gradual infusion over time. The administration may, for example, be oral, intravenous, intraperitoneal, intramuscular, intracavity, subcutaneous, or transdermal. When antibodies are used therapeutically, a preferred route of administration is by pulmonary aerosol. Techniques for preparing aerosol delivery systems containing antibodies are well known to those of skill in the art. Generally, such systems should utilize components which will not significantly impair the biological properties of the antibodies, such as the paratope binding capacity (see, for example, Sciarra and Cutie, “Aerosols,” in Remington's Pharmaceutical Sciences, 18th edition, 1990, pp 1694-1712; incorporated by reference). Those of skill in the art can readily determine the various parameters and conditions for producing antibody aerosols without resort to undue experimentation. When using antisense preparations of the invention, slow intravenous administration is preferred.

[0068]As used herein, the term “antisense molecule” or “antisense” describes an oligonucleotide that is an oligoribonucleotide, oligodeoxyribonucleotide, modified oligoribonucleotide, or modified oligodeoxyribonucleotide which hybridises under physiological conditions to DNA comprising a particular gene or to an mRNA transcript of that gene and, thereby, inhibits the transcription of that gene and / or the translation of that mRNA. The antisense molecules are designed so as to interfere with transcription or translation of a target gene upon hybridisation with the target gene or transcript. Those skilled in the art will recognise that the exact length of the antisense oligonucleotide and its degree of complementarity with its target will depend upon the specific target selected, including the sequence of the target and the particular bases which comprise that sequence. It is preferred that the antisense oligonucleotide be constructed and arranged so as to bind selectively with the target under physiological conditions, i.e., to hybridise substantially more to the target sequence than to any other sequence in the target cell under physiological conditions. Based upon the iASPP6C nucleic acid sequences provided herein, or upon allelic or homologous genomic and / or cDNA sequences, one of skill in the art can easily choose and synthesise any of a number of appropriate antisense molecules for use in accordance with the present invention. For example, a “gene walk” comprising a series of oligonucleotides of 15-30 nucleotides spanning the length of iASPP6C nucleic acid can be prepared, followed by testing for inhibition of the corresponding iASPP6C expression. Optionally, gaps of 5-10 nucleotides can be left between the oligonucleotides to reduce the number of oligonucleotides synthesised and tested.

[0099]It will be apparent to one skilled in the art that modification to the amino acid sequence of peptides agents could enhance the binding and / or stability of the peptide with respect to its target sequence. In addition, modification of the peptide may also increase the in vivo stability of the peptide thereby reducing the effective amount of peptide necessary to inhibit p53 binding of iASPP. This would advantageously reduce undesirable side effects which may result in vivo. Modifications include, by example and not by way of limitation, acetylation and amidation. Alternatively or preferably, said modification includes the use of modified amino acids in the production of recombinant or synthetic forms of peptides. It will be apparent to one skilled in the art that modified amino acids include, by way of example and not by way of limitation, 4-hydroxyproline, 5-hydroxylysine, N6-acetyllysine, N6-methyllysine, N6,N6-dimethyllysine, N6,N6,N6-trimethyllysine, cyclohexyalanine, D-amino acids, ornithine. Other modifications include amino acids with a C2, C3 or C4 alkyl R group optionally substituted by 1, 2 or 3 substituents selected from halo (eg F, Br, I), hydroxy or C1-C4 alkoxy. Modifications also include, by example and not by way of limitation, acetylation and amidation.

Problems solved by technology

Mutations in tumour suppressor genes result in abnormal cell-cycle progression whereby the normal cell-cycle check points which arrest the cell-cycle, when, for example, DNA is damaged, are ignored and damaged cells divide uncontrollably.

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