Comparative Efficacy of Ribosome-Inactivating Protein-Containing Immunotoxins in 2D and 3D Models of Sarcoma

Sarcomas are very complex and clinically challenging mesenchymal tumors. Although the standard therapeutic approach has improved the 5-year survival rate, many patients experience local relapses and/or distant metastases. To improve patient outcome, new strategies need to be investigated. Immunotoxi...

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Main Authors: Giulia Calafato, Massimo Bortolotti, Letizia Polito, Andrea Bolognesi
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Toxins
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Online Access:https://www.mdpi.com/2072-6651/17/6/308
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author Giulia Calafato
Massimo Bortolotti
Letizia Polito
Andrea Bolognesi
author_facet Giulia Calafato
Massimo Bortolotti
Letizia Polito
Andrea Bolognesi
author_sort Giulia Calafato
collection DOAJ
description Sarcomas are very complex and clinically challenging mesenchymal tumors. Although the standard therapeutic approach has improved the 5-year survival rate, many patients experience local relapses and/or distant metastases. To improve patient outcome, new strategies need to be investigated. Immunotoxins (ITs) based on rRNA N-glycosylases (also named ribosome-inactivating proteins, RIPs) are promising tools for cancer therapy because, by combining rRNA-glycosylase’s high cytotoxicity with carrier selectivity, they can specifically eliminate target neoplastic cells. In the last few years, 3D models have been extensively used in cancer research, particularly for target-specific drug screening. This study aimed to evaluate the possibility of utilizing ribosome-inactivating protein (RIP)-containing ITs to selectively target TfR1-, EGFR1- and Her2-expressing sarcoma adherent cells (ACs), spheroids (SSs) and organoids (ORs). To compare Its’ efficacy and ability to induce apoptosis, we performed dose–response viability and caspase 3/7 activation assays on rhabdomyosarcoma and osteosarcoma ACs, SSs and ORs treated with Tf-IT, αEGFR1-IT and αHer2-IT. Our results indicate that, compared to the corresponding unconjugated RIPs, all ITs showed increased cytotoxicity in sarcoma ACs. Despite the increased complexity characterizing 3D models, the higher IC<sub>50</sub> differences between ITs and unconjugated RIPs were obtained in ORs, which appeared more resistant to the nonspecific killing of the RIPs than either the ACs or SSs, thus augmenting the therapeutic window between unconjugated and conjugated RIPs. IT induced a more delayed apoptosis in 3D compared to 2D models. Our results provide essential outcomes for the potential use of these RIP-based ITs as a therapeutic strategy to treat sarcoma.
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spelling doaj-art-4962100aaef34e4caa98c5405a943fc92025-08-20T03:29:38ZengMDPI AGToxins2072-66512025-06-0117630810.3390/toxins17060308Comparative Efficacy of Ribosome-Inactivating Protein-Containing Immunotoxins in 2D and 3D Models of SarcomaGiulia Calafato0Massimo Bortolotti1Letizia Polito2Andrea Bolognesi3IRCCS Azienda Ospedaliero-Universitaria di Bologna, 40138 Bologna, ItalyDepartment of Medical and Surgical Sciences—DIMEC, Alma Mater Studiorum, University of Bologna, 40126 Bologna, ItalyDepartment of Medical and Surgical Sciences—DIMEC, Alma Mater Studiorum, University of Bologna, 40126 Bologna, ItalyDepartment of Medical and Surgical Sciences—DIMEC, Alma Mater Studiorum, University of Bologna, 40126 Bologna, ItalySarcomas are very complex and clinically challenging mesenchymal tumors. Although the standard therapeutic approach has improved the 5-year survival rate, many patients experience local relapses and/or distant metastases. To improve patient outcome, new strategies need to be investigated. Immunotoxins (ITs) based on rRNA N-glycosylases (also named ribosome-inactivating proteins, RIPs) are promising tools for cancer therapy because, by combining rRNA-glycosylase’s high cytotoxicity with carrier selectivity, they can specifically eliminate target neoplastic cells. In the last few years, 3D models have been extensively used in cancer research, particularly for target-specific drug screening. This study aimed to evaluate the possibility of utilizing ribosome-inactivating protein (RIP)-containing ITs to selectively target TfR1-, EGFR1- and Her2-expressing sarcoma adherent cells (ACs), spheroids (SSs) and organoids (ORs). To compare Its’ efficacy and ability to induce apoptosis, we performed dose–response viability and caspase 3/7 activation assays on rhabdomyosarcoma and osteosarcoma ACs, SSs and ORs treated with Tf-IT, αEGFR1-IT and αHer2-IT. Our results indicate that, compared to the corresponding unconjugated RIPs, all ITs showed increased cytotoxicity in sarcoma ACs. Despite the increased complexity characterizing 3D models, the higher IC<sub>50</sub> differences between ITs and unconjugated RIPs were obtained in ORs, which appeared more resistant to the nonspecific killing of the RIPs than either the ACs or SSs, thus augmenting the therapeutic window between unconjugated and conjugated RIPs. IT induced a more delayed apoptosis in 3D compared to 2D models. Our results provide essential outcomes for the potential use of these RIP-based ITs as a therapeutic strategy to treat sarcoma.https://www.mdpi.com/2072-6651/17/6/308rRNA N-glycosylasesribosome-inactivating proteinsimmunotoxinsimmunoconjugatestargeted therapysarcoma
spellingShingle Giulia Calafato
Massimo Bortolotti
Letizia Polito
Andrea Bolognesi
Comparative Efficacy of Ribosome-Inactivating Protein-Containing Immunotoxins in 2D and 3D Models of Sarcoma
Toxins
rRNA N-glycosylases
ribosome-inactivating proteins
immunotoxins
immunoconjugates
targeted therapy
sarcoma
title Comparative Efficacy of Ribosome-Inactivating Protein-Containing Immunotoxins in 2D and 3D Models of Sarcoma
title_full Comparative Efficacy of Ribosome-Inactivating Protein-Containing Immunotoxins in 2D and 3D Models of Sarcoma
title_fullStr Comparative Efficacy of Ribosome-Inactivating Protein-Containing Immunotoxins in 2D and 3D Models of Sarcoma
title_full_unstemmed Comparative Efficacy of Ribosome-Inactivating Protein-Containing Immunotoxins in 2D and 3D Models of Sarcoma
title_short Comparative Efficacy of Ribosome-Inactivating Protein-Containing Immunotoxins in 2D and 3D Models of Sarcoma
title_sort comparative efficacy of ribosome inactivating protein containing immunotoxins in 2d and 3d models of sarcoma
topic rRNA N-glycosylases
ribosome-inactivating proteins
immunotoxins
immunoconjugates
targeted therapy
sarcoma
url https://www.mdpi.com/2072-6651/17/6/308
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