title: Combinatorial screenings in patients: the interleukin-11 receptor alpha as a candidate target in the progression of human prostate cancer.
abstract: Direct screening of combinatorial peptide libraries in patients may allow the identification of ligands that target biochemical differences in the endothelium of blood vessels. In a screening performed in a patient, we selected and isolated a mimic motif of interleukin 11 (IL-11) from prostate biopsies after an i.v. administration of a phage display peptide library. We also demonstrated that the IL-11 phage mimic (displaying the cyclic nonapeptide CGRRAGGSC) bound specifically to a corresponding IL-11 receptor (IL-11Ralpha). Here we show that IL-11Ralpha is a potential target for intervention in human prostate cancer through morphological and functional analyses. First, a comprehensive serial immunohistochemical analysis of primary and metastatic prostate cancer samples showed increased stage-specific expression of IL-11Ralpha during disease progression. Second, a proapoptotic peptide was specifically targeted and internalized through this functional IL-11Ralpha-based ligand-receptor pair: treatment of prostate cancer cells in vitro with a proapoptotic peptide guided by the CGRRAGGSC peptide to the IL-11Ralpha resulted in dose-dependent apoptosis. Together, these data indicate that the IL-11Ralpha is a candidate target for translational clinical trials against advanced and metastatic prostate cancer. Moreover, our results illustrate the ability of direct combinatorial screening systems in cancer patients for identification of relevant targets in the context of human disease.
authors.affiliation: Department of Genitourinary Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: Amado J
authors.initials: AJ
authors.lastname: Zurita
authors.forename: Patricia
authors.initials: P
authors.lastname: Troncoso
authors.forename: Marina
authors.initials: M
authors.lastname: Cardó-Vila
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Logothetis
authors.forename: Renata
authors.initials: R
authors.lastname: Pasqualini
authors.forename: Wadih
authors.initials: W
authors.lastname: Arap
mesh_terms: D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000032:analysis; D045744:Cell Line, Tumor; D018450:Disease Progression; D006801:Humans; D053703:Interleukin-11 Receptor alpha Subunit; D008297:Male; D011467:Prostate / Q000276:immunology; D011471:Prostatic Neoplasms / Q000235:genetics / Q000473:pathology*; D018123:Receptors, Interleukin / Q000032:analysis* / Q000235:genetics; D053702:Receptors, Interleukin-11; D012016:Reference Values
chemical_list: D014408:Biomarkers, Tumor; C508428:IL11RA protein, human; D053703:Interleukin-11 Receptor alpha Subunit; D018123:Receptors, Interleukin; D053702:Receptors, Interleukin-11