Data from Peptides and Aptamers Targeting HSP70: A Novel Approach for Anticancer Chemotherapy

<div>Abstract<p>The inhibition of heat shock protein 70 (HSP70) is an emerging strategy in cancer therapy. Unfortunately, no specific inhibitors are clinically available. By yeast two-hybrid screening, we have identified multiple peptide aptamers that bind HSP70. When expressed in human tumor cells, two among these peptide aptamers—A8 and A17—which bind to the peptide-binding and the ATP-binding domains of HSP70, respectively, specifically inhibited the chaperone activity, thereby increasing the cells' sensitivity to apoptosis induced by anticancer drugs. The 13-amino acid peptide from the variable region of A17 (called P17) retained the ability to specifically inhibit HSP70 and induced the regression of subcutaneous tumors <i>in vivo</i> after local or systemic injection. This antitumor effect was associated with an important recruitment of macrophages and T lymphocytes into the tumor bed. Altogether, these data indicate that peptide aptamers or peptides that target HSP70 may be considered as novel lead compounds for cancer therapy. <i>Cancer Res; 71(2); 484–95. ©2011 AACR</i>.</p></div>