Anti-androgen peptides and uses thereof in cancer therapy

Abstract

The present invention relates to isolated or purified or partially purified peptide derived molecules having the following general formula (S1): X-[(Pro)n-His-Pro-His-Ala-Arg-Ile-Lys]m-Y. The peptides are for medical use, in particular as anti-tumoral agents.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to native, site specifically mutated, and synthetic peptides comprising portions of the human androgen receptor and composition thereof. The invention also relates to antibodies raised against these peptides and polynucleotides encoding these peptides. Also provided are methods for synthesizing derivatives of these peptides and their use as anti-androgen compositions in the treatment and / or prevention of prostate and / or breast cancers, preparation of pharmaceutical compositions, diagnostic kits, and development of related assays for use in anticancer therapies.STATE OF THE ARTAndrogen Receptor in Human Prostate and Mammary Cancers[0002]The androgen receptor (AR) is a ligand-activated transcriptional regulatory protein that mediates induction of male sexual development and function through its activity with endogenous androgens (Roy et al, 1999). Androgens are generally known as the male sex hormones. The androgenic hormo...

AI Technical Summary

Benefits of technology

[0010]The peptide-derived molecule is able to inhibit or prevent the interaction of the androgen receptor (AR) with the SH3 domain of the tyrosine kinase Src.

[0028]In another embodiment the invention provides a method for reducing androgen receptor activity in a cell providing to the cell an amount of an anti-androgen peptide. The cell may be in culture, or comprised in an animal, which has been diagnosed with a cancer such as prostate or a breast carcinoma.

[0034]A polypeptide or protein that is “purified to homogeneity,” as applied to the present invention, means that the polypeptide or protein has a level of purity where the polypeptide or protein is substantially free from other proteins and biological components. For example, a purified polypeptide will often be sufficiently free of other peptide components so that degradative sequencing may be performed successfully.

[0035]This invention is particularly concerned with proline-rich peptide derivatives such as isolated peptides of at least four or more residues in length, including those peptides up to and including about 50 or so amino acids, which comprise the amino acid sequences derived from the general formulae S1. Preferably, these peptides inhibit AR association to Src-SH3 domain, and are active in treating tumors and prostate and breast cancers in an affected animal, such as a human. The use of small peptides in therapeutics is preferred for various reasons. These include the low cost and ease of large scale preparation, and the reliability of the product. Also their biological properties are preferable, such as the ease with which peptides can penetrate tissues, their low immunogenicity, the fact that they present a smaller target for proteases thus affording longer bioavailability and, further, it is contemplated that they will function effectively in the prevention of AR-Src interaction and functioning as anti-androgen therapeutics.

[0056]The use of a hybridization probe of about 14 nucleotides in length allows the formation of a duplex molecule that is both stable and selective. Molecules having contiguous complementary sequences over stretches greater than 14 bases in length are generally preferred, though, in order to increase stability and selectivity of the hybrid, and thereby improve the quality and degree of specific hybrid molecules obtained. One will generally prefer to design nucleic acid molecules having gene-complementary stretches of 15 to 20 contiguous nucleotides, or even longer where desired.

Problems solved by technology

However, when androgen ablation therapy ultimately fails, prostate cancer progresses to a hormone refractory state.

Although these tumors are refractory in the sense that they have progressed despite a reduction in serum androgen and / or treatment with anti-androgens, the majority of these tumors are unlikely to be completely resistant to androgens.

With time, breast cancer finds ways to grow without the need for estrogen and becomes lethal.

Unfortunately, these and similar approaches frequently become ineffective because of development of drug resistance.

In addition, these compounds have some undesirable side effects like increased risk of cardiovascular complications and, after chronic use, a small increased incidence of uterus carcinoma.

In addition, the peptides disclosed in WO 00 / 1813 have not been shown to reduce or block prostate or breast tumor cell growth.

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