Immunohistochemical detection of arginine methylated proteins (MeRP) in archival tissues

Marzia Vezzalini (1) , John M Aletta (2) , Stefania Beghelli (1) , Eisabetta Moratti (1) , Marco Della Peruta (1) , Andrea Mafficini (1) , Wilfrido D. Mojica (3) , Aldo Mombello (1) , Aldo Scarpa (1) , Claudio Sorio (1)

1 Department of Pathology
2 New York State Center of Excellence in Bioinformatics & Life Sciences
3 Department of Pathology

Aims: i) To determine if methylarginine-specific antibodies can be employed for standard immunohistochemical analysis of paraffin-embedded tissues, ii) analyze methylarginine expression in normal and neoplastic tissues, and iii) correlate methylarginine expression with that of PRMT1, the predominant cellular arginine methyltransferase. Methods and Results: Immunohistochemical staining of normal and cancer tissues utilizing three commercial polyclonal antibodies: anti-mRG raised against a methylarginine peptide, anti-RG, a control antiserum raised against a corresponding arginine peptide without any methylated residues, and anti-PRMT1. Nuclear and/or cytoplasmic methylarginine expression was detected in all keratinized and non-keratinized epithelia. A preliminary survey of a series of thyroid, pancreatic, colon and gastric cancers identified a different pattern of methylarginine expression in comparison with normal tissue. A correlation between methylarginine staining and PRMT1 expression was found in all normal and cancer tissues analyzed. Conclusion: This study reports for the first time that methylarginine-specific antibodies are capable of recognizing MeRP in paraffin-embedded tissues. Methylarginine proteins are widely expressed and show differences in subcellular localization in various organs and neoplastic conditions. The efficient detection of methylproteins by standard immunohistochemistry demonstrated in this study provides a new tool to investigate the role of MeRP in biological processes including carcinogenesis.

Mots clés: Medicine

Marzia Vezzalini, John M Aletta, Stefania Beghelli, Eisabetta Moratti, Marco Della Peruta, et al.. Immunohistochemical detection of arginine methylated proteins (MeRP) in archival tissues. Histopathology, 2010, 57 (5), pp.725. ⟨10.1111/j.1365-2559.2010.03684.x⟩. ⟨hal-00593449⟩