Author(s):
Loureiro, Liliana R. ; Sousa, Diana P. ; Ferreira, Dylan ; Chai, Wengang ; Lima, Luís Carlos Oliveira ; Pereira, Carina ; Lopes, Carla B. ; Correia, Viviana G. ; Silva, Lisete M. ; Li, Chunxia ; Santos, Lúcio Lara ; Ferreira, José Alexandre ; Barbas, Ana ; Palma, Angelina S. ; Novo, Carlos ; Videira, Paula A.
Date: 2018
Persistent ID: http://hdl.handle.net/10362/147031
Origin: Repositório Institucional da UNL
Project/scholarship:
info:eu-repo/grantAgreement/FCT/PD/PD%2FBD%2F105727%2F2014/PT;
info:eu-repo/grantAgreement/FCT/5876/147258/PT;
Subject(s): General; SDG 3 - Good Health and Well-being
Description
This work was supported by the Bluepharma innovation award "Trifunctional antibodies and dendritic cell-based technologies: a combined approach to cancer immunotherapy" 2013 and the Scientific merit prize Santander - Totta - Lisbon New University - "Antibody engineering for breast cancer therapy" 2013. LRL is supported by the grant PD/BD/52476/2013 from the Portuguese Foundation for Science and Technology (FCT). The work is partially supported by FCT-MCTES through the grants IF/00033/2012 (ASP), SFRH/BPD/101827/2014 (LL) and SFRH/BPD/111048/2015 (JAF), the Wellcome Trust Biomedical Resource grant (WC) and the NSFC-Shandong Joint Fund (U1606403) (CL). The authors also acknowledge FCT funding for CI-IPOP research unit (PEst-OE/SAU/UI0776/201). co-financed by the European Regional Development Fund under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007728). FCT is co-financed by European Social Fund (ESF) under Human Potential Operation Programme (POPH) from National Strategic Reference Framework (NSRF). The funders did not play a role in the study design, data collection or decision to publish.
Incomplete O-glycosylation is a feature associated with malignancy resulting in the expression of truncated glycans such as the sialyl-Tn (STn) antigen. Despite all the progress in the development of potential anti-cancer antibodies, their application is frequently hindered by low specificities and cross-reactivity. In this study, a novel anti-STn monoclonal antibody named L2A5 was developed by hybridoma technology. Flow cytometry analysis showed that L2A5 specifically binds to sialylated structures on the cell surface of STn-expressing breast and bladder cancer cell lines. Moreover, immunoblotting assays demonstrated reactivity to tumour-associated O-glycosylated proteins, such as MUC1. Tumour recognition was further observed using immunohistochemistry assays, which demonstrated a high sensitivity and specificity of L2A5 mAb towards cancer tissue, using bladder and colorectal cancer tissues. L2A5 staining was exclusively tumoural, with a remarkable reactivity in invasive and metastasis sites, not detectable by other anti-STn mAbs. Additionally, it stained 20% of cases of triple-negative breast cancers, suggesting application in diseases with unmet clinical needs. Finally, the fine specificity was assessed using glycan microarrays, demonstrating a highly specific binding of L2A5 to core STn antigens and additional ability to bind 2–6-linked sialyl core-1 probes. In conclusion, this study describes a novel anti-STn antibody with a unique binding specificity that can be applied for cancer diagnostic and future development of new antibody-based therapeutic applications.
