Open Access

ARTICLE

Assessing the impact of CD73 inhibition on overcoming anti-EGFR resistance in glioma cells

LUIZ FERNANDO LOPES SILVA^1,#, JULIETE NATHALI SCHOLL^1,#, AUGUSTO FERREIRA WEBER¹, CAMILA KEHL DIAS¹, PAULINE RAFAELA PIZZATO², VINíCIUS PIERDONá LIMA¹, JEAN SÉVIGNY^3,4, ANA MARIA OLIVEIRA BATTASTINI¹, FABRÍCIO FIGUEIRÓ^1,2,*

1Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003, Brazil
2Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS 90035-003, Brazil
3 Département de microbiologie-infectiologie et d’immunologie, Faculté de Médecine, Université Laval, Québec City, G1V 0A6, Canada
4 Axe maladies infectieuses et immunitaires, Centre de recherche du CHU de Québec, Université Laval, Québec City, G1V 4G2, Canada

* Corresponding Author: FABRÍCIO FIGUEIRÓ. Email:
# These two authors contributed equally to this work

Oncology Research 2025, 33(4), 951-964. https://doi.org/10.32604/or.2024.055508

Received 28 June 2024; Accepted 19 November 2024; Issue published 19 March 2025

Abstract

Objectives: Glioblastoma (GB) is a grade IV glial tumor characterized by high malignancy and dismal prognosis, primarily due to high recurrence rates and therapeutic resistance. The epidermal growth factor receptor (EGFR), a receptor tyrosine kinase (RTK), regulates signaling pathways, including cell growth, proliferation, survival, migration, and cell death. Many cancers utilize immune checkpoints (ICs) to attenuate immune responses. CD73 is an enzyme that functions as an IC by hydrolyzing AMP to adenosine, suppressing immune cells in the tumor microenvironment. However, the role of CD73 in resistance to EGFR inhibitors is poorly understood. This study aims to elucidate the resistance mechanisms induced by anti-EGFR treatment and to evaluate an anti-CD73 approach to overcome resistance mediated by anti-EGFR monotherapy. Methods: The U251 GB cell line was treated with AG1478, an EGFR inhibitor, and the resistance markers MRP-1, PD-L1, and CD73 were evaluated using flow cytometry. Additionally, we assessed the combination effects of AG1478 and APCP (an EGFR and a CD73 inhibitor, respectively) on cell cycle progression, proliferation, apoptosis, and migration in vitro. Results: We observed high EGFR, PD-L1, and CD73 expression in human GB cells. The treatment with AG1478 increased the expression of resistance markers MRP-1, PD-L1, and CD73, whereas it decreased CTLA-4. The combination of AG1478 and APCP did not alter proliferation or apoptosis but interfered with cell cycling, arresting the cells in the G1 phase, decreasing cell motility and partially reversing MRP-1 overexpression. Conclusion: In summary, our findings indicate that CD73 inhibition has a modest effect in overcoming resistance to EGFR monotherapy in vitro. Thus, further in vivo studies are needed, as the inhibition of both EGFR and CD73 affects cells in the tumor microenvironment and could potentially enhance anti-tumor immunity.

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