A subtraction tolerization method of immunization allowed for Wilms' tumor protein-1 (WT1) identification in melanoma and discovery of an antitumor peptide sequence

Author(s)

Massaoka, Mariana H. ^[1] ; Matsuo, Alisson L. ^[1] ; Figueiredo, Carlos R. ^[1] ; Girola, Natalia ^[1] ; Farias, Camyla F. ^[1] ; Pasqualoto, Kerly ^[2] ; Travassos, Luiz R. ^[1]

Affiliation

^[1] Univ Fed Sao Paulo, Dept Microbiol Immunol & Parasitol, Expt Oncol Unit, Sao Paulo - Brazil

^[2] Butantan Inst, Biochem & Biophys Lab, Sao Paulo - Brazil

• Document type: Journal article
• Source: JOURNAL OF IMMUNOLOGICAL METHODS; v. 414, p. 11-19, DEC 1 2014.
• Web of Science Citations: 2

Abstract

On searching for melanoma transcription factors in a project focusing on internal antitumor peptide sequences from transcription factors, we found that a highly immunogenic component emerged upon using a subtraction tolerization method of immunization. While several conventional immunization procedures using whole melanoma cells induced a plethora of low affinity antibodies of various specificities, the subtraction tolerization method efficiently elicited mono-specific antibodies that recognized Wilms' tumor protein 1 (WT1), which is known as an important marker in melanoma prognosis and treatment For the tolerization step, pre-immunization of Balb/c mice with a membrane-rich preparation of glioblastoma U87 cells was used. The subsequent immunizations with SK-MEL-28 melanoma cells elicited antibodies strongly reacting with 50 and 55 kDa proteins, identified as WT1. Remarkably, this was the only component strongly reactive with these antibodies in a melanoma cell lysate. WT1 was then chosen as a target for selecting internally bioactive peptides. A hydrophilic Trojan peptide containing most of the zinc finger-2 domain of WT1 was synthesized and shown to inhibit SK-MEL-28 melanoma growth in vitro. The peptide WT1-pTj was also protective in vivo in a metastatic melanoma model and peptide-stimulated syngeneic dendritic cells reproduced the anti-melanoma effect of the unprotected peptide. Identification of antitumor peptides derived from major transcription factors represents a new tool to be explored in cancer research aiming at new therapeutic drugs. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 10/51423-0 - Bioactive peptides and peptidases: biological and immunobiological activities in infectious diseases and cancer
• Grantee: Luiz Rodolpho Raja Gabaglia Travassos
• Support Opportunities: Research Projects - Thematic Grants