title: Proteasome activator complex PA28 identified as an accessible target in prostate cancer by in vivo selection of human antibodies.
abstract: Antibody cancer therapies rely on systemically accessible targets and suitable antibodies that exert a functional activity or deliver a payload to the tumor site. Here, we present proof-of-principle of in vivo selection of human antibodies in tumor-bearing mice that identified a tumor-specific antibody able to deliver a payload and unveils the target antigen. By using an ex vivo enrichment process against freshly disaggregated tumors to purge the repertoire, in combination with in vivo biopanning at optimized phage circulation time, we have identified a human domain antibody capable of mediating selective localization of phage to human prostate cancer xenografts. Affinity chromatography followed by mass spectrometry analysis showed that the antibody recognizes the proteasome activator complex PA28. The specificity of soluble antibody was confirmed by demonstrating its binding to the active human PA28αβ complex. Whereas systemically administered control phage was confined in the lumen of blood vessels of both normal tissues and tumors, the selected phage spread from tumor vessels into the perivascular tumor parenchyma. In these areas, the selected phage partially colocalized with PA28 complex. Furthermore, we found that the expression of the α subunit of PA28 [proteasome activator complex subunit 1 (PSME1)] is elevated in primary and metastatic human prostate cancer and used anti-PSME1 antibodies to show that PSME1 is an accessible marker in mouse xenograft tumors. These results support the use of PA28 as a tumor marker and a potential target for therapeutic intervention in prostate cancer.
authors.affiliation: Molecular Immunology Unit, Hospital Universitario Puerta de Hierro Majadahonda, 28222 Majadahonda, Madrid, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Sánchez-Martín
authors.forename: Jorge
authors.initials: J
authors.lastname: Martínez-Torrecuadrada
authors.forename: Tambet
authors.initials: T
authors.lastname: Teesalu
authors.forename: Kazuki N
authors.initials: KN
authors.lastname: Sugahara
authors.forename: Ana
authors.initials: A
authors.lastname: Alvarez-Cienfuegos
authors.forename: Pilar
authors.initials: P
authors.lastname: Ximénez-Embún
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Fernández-Periáñez
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Martín
authors.forename: Irene
authors.initials: I
authors.lastname: Molina-Privado
authors.forename: Isabel
authors.initials: I
authors.lastname: Ruppen-Cañás
authors.forename: Ana
authors.initials: A
authors.lastname: Blanco-Toribio
authors.forename: Marta
authors.initials: M
authors.lastname: Cañamero
authors.forename: Angel M
authors.initials: AM
authors.lastname: Cuesta
authors.forename: Marta
authors.initials: M
authors.lastname: Compte
authors.forename: Leonor
authors.initials: L
authors.lastname: Kremer
authors.forename: Carmen
authors.initials: C
authors.lastname: Bellas
authors.forename: Vanesa
authors.initials: V
authors.lastname: Alonso-Camino
authors.forename: Irene
authors.initials: I
authors.lastname: Guijarro-Muñoz
authors.forename: Laura
authors.initials: L
authors.lastname: Sanz
authors.forename: Erkki
authors.initials: E
authors.lastname: Ruoslahti
authors.forename: Luis
authors.initials: L
authors.lastname: Alvarez-Vallina
mesh_terms: D000818:Animals; D000912:Antibodies, Neoplasm / Q000276:immunology* / Q000378:metabolism; D000918:Antibody Specificity; D014408:Biomarkers, Tumor / Q000276:immunology*; D015153:Blotting, Western; D061505:Cell Surface Display Techniques; D002846:Chromatography, Affinity; D002853:Chromatography, Liquid; D016503:Drug Delivery Systems / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D007167:Immunotherapy / Q000379:methods*; D008297:Male; D051379:Mice; D008819:Mice, Nude; D009124:Muscle Proteins / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000276:immunology* / Q000628:therapy; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D018709:Statistics, Nonparametric; D053719:Tandem Mass Spectrometry
chemical_list: D000912:Antibodies, Neoplasm; D014408:Biomarkers, Tumor; D009124:Muscle Proteins; C085047:PSME1 protein, human; D046988:Proteasome Endopeptidase Complex
keywords: phage display; phage library; physiological selection; single domain antibody; tumor-associated antigen
references.citation: Ann N Y Acad Sci. 2008;1131:37-43
references.pmid: 18519957
references.citation: Protein Expr Purif. 2009 Apr;64(2):219-24
references.pmid: 19017543
references.citation: Proc Natl Acad Sci U S A. 1998 Apr 14;95(8):4607-12
references.pmid: 9539785
references.citation: Biochem J. 2000 Feb 15;346 Pt 1:155-61
references.pmid: 10657252
references.citation: Cancer Res. 2000 Feb 1;60(3):722-7
references.pmid: 10676659
references.citation: J Immunol Methods. 1999 May 27;225(1-2):171-8
references.pmid: 10365793
references.citation: PLoS Med. 2008 Apr 15;5(4):e85
references.pmid: 18416599
references.citation: J Biol Chem. 2011 Feb 18;286(7):5197-203
references.pmid: 21156793
references.citation: Mol Biol Rep. 2004 Jun;31(2):121-9
references.pmid: 15293788
references.citation: J Mol Biol. 2008 Feb 29;376(4):926-31
references.pmid: 18199455
references.citation: Biophys J. 2002 Jul;83(1):566-81
references.pmid: 12080143
references.citation: Am J Pathol. 2012 Jun;180(6):2576-89
references.pmid: 22521648
references.citation: Trends Biotechnol. 2010 Jul;28(7):355-62
references.pmid: 20447706
references.citation: Nature. 1997 Dec 11;390(6660):639-43
references.pmid: 9403698
references.citation: Science. 2000 Aug 18;289(5482):1197-202
references.pmid: 10947988
references.citation: Neoplasia. 2006 Sep;8(9):772-80
references.pmid: 16984734
references.citation: Nature. 1996 Mar 28;380(6572):364-6
references.pmid: 8598934
references.citation: PLoS One. 2011;6(6):e20594
references.pmid: 21731618
references.citation: Proc Natl Acad Sci U S A. 2011 Nov 15;108(46):18637-42
references.pmid: 22049339
references.citation: J Immunol Methods. 2000 May 26;239(1-2):137-51
references.pmid: 10821955
references.citation: Cancer Res. 2006 Jun 1;66(11):5696-706
references.pmid: 16740707
references.citation: Virology. 2002 Feb 1;293(1):182-91
references.pmid: 11853411
references.citation: FASEB J. 2006 May;20(7):979-81
references.pmid: 16581960
references.citation: Cell Mol Life Sci. 2011 May;68(9):1491-502
references.pmid: 21387144
references.citation: Protein Eng Des Sel. 2009 Mar;22(3):217-20
references.pmid: 18957405
references.citation: Methods Enzymol. 2012;503:35-56
references.pmid: 22230564
references.citation: Immunogenetics. 1999 May;49(5):438-45
references.pmid: 10199920
references.citation: Mol Cancer Res. 2007 Jan;5(1):11-9
references.pmid: 17259343
references.citation: Nat Rev Immunol. 2010 May;10(5):345-52
references.pmid: 20414207
references.citation: Nature. 2004 Jun 10;429(6992):629-35
references.pmid: 15190345
references.citation: Cancer Res. 2008 Sep 1;68(17):7210-8
references.pmid: 18757437
references.citation: Molecules. 2011 Jan 21;16(1):857-87
references.pmid: 21258295
references.citation: J Proteome Res. 2011 Jun 3;10(6):2863-72
references.pmid: 21517111
references.citation: Nature. 2005 Dec 15;438(7070):932-6
references.pmid: 16355210
references.citation: J Biol Chem. 1993 Sep 25;268(27):20205-10
references.pmid: 7690752
references.citation: J Proteome Res. 2007 Nov;6(11):4127-34
references.pmid: 17939699
references.citation: Nat Rev Cancer. 2005 Jun;5(6):436-46
references.pmid: 15928674
references.citation: Nat Rev Immunol. 2010 May;10(5):317-27
references.pmid: 20414205
references.citation: Nature. 1996 May 9;381(6578):166-8
references.pmid: 8610016
references.citation: Med Sci Monit. 2010 Aug;16(8):BR233-45
references.pmid: 20671603
references.citation: Curr Opin Chem Biol. 2010 Aug;14(4):529-37
references.pmid: 20643572
references.citation: Phys Rev Lett. 2006 Jul 28;97(4):048101
references.pmid: 16907613
references.citation: J Cell Biol. 2003 Nov 24;163(4):871-8
references.pmid: 14638862
references.citation: Mol Immunol. 2002 Oct;39(3-4):165-9
references.pmid: 12200048
references.citation: Curr Drug Metab. 2012 Jan;13(1):4-21
references.pmid: 22292808
references.citation: J Cell Biol. 2010 Mar 22;188(6):759-68
references.pmid: 20231381
references.citation: Nat Med. 2002 Jul;8(7):751-5
references.pmid: 12053175
references.citation: Proc Natl Acad Sci U S A. 2009 Sep 22;106(38):16157-62
references.pmid: 19805273
references.citation: PLoS One. 2009 Dec 17;4(12):e8338
references.pmid: 20020040
references.citation: Nature. 2005 Dec 15;438(7070):967-74
references.pmid: 16355214
references.citation: Nat Rev Drug Discov. 2010 Oct;9(10):767-74
references.pmid: 20811384
references.citation: Nat Methods. 2005 Apr;2(4):291-8
references.pmid: 15782212
references.citation: Biochem Soc Trans. 2004 Jun;32(Pt3):397-402
references.pmid: 15157146