Expression of thimet oligopeptidase (THOP) modulated by oxidative stress in human multidrug resistant (MDR) leukemia cells

Autor(es)

Neves, Raquel Leao ; Marem, Alyne ; Carmona, Bruno ; Arata, Julia Galanakis ; Ramos, Marcos Paulo Cyrillo ; Justo, Giselle Zenker ; de Melo, Fabiana Henriques Machado ; Oliveira, Vitor ; Icimoto, Marcelo Yudi

• Tipo de documento: Artigo Científico
• Fonte: Biochimie; v. 212, p. 10-pg., 2023-04-14.

Resumo

Thimet oligopeptidase (THOP) is a cytosolic metallopeptidase known to regulate the fate of post-proteasomal peptides, protein turnover and peptide selection in the antigen presentation machinery (APM) system. Oxidative stress influences THOP expression and regulates its proteolytic activity, generating variable cytosolic peptide levels, possibly affecting the immune evasion of tumor cells. In the present work, we examined the association between THOP expression/activity and stress oxidative resistance in human leukemia cells using the K562 cell line, a chronic myeloid leukemia (CML), and the multidrug-resistant (MDR) Lucena 1 (K562-derived MDR cell line) as model. The Lucena 1 phenotype was validated under vincristine treatment and the relative THOP1 mRNA levels and protein expression compared to K562 cell line. Our data demonstrated increased THOP1 gene and protein levels in K562 cells in contrast to the oxidative-resistant Lucena 1, even after H2O2 treatment, suggesting an oxidative stress dependence in THOP regulation. Further, it was observed higher basal levels of reactive oxygen species (ROS) in K562 compared to Lucena 1 cell line using DHE fluorescent probe. Since THOP activity is dependent on its oligomeric state, we also compared its proteolytic activity under reducing agent treatment, which demonstrated that its function modulation with respect to changes in redox state. Finally, the mRNA expression and FACS analyses demonstrated a reduced expression of MHC I only in K562 cell line. In conclusion, our results highlight THOP redox modulation, which could influence an-tigen presentation in multidrug resistant leukemia cells.(c) 2023 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved. (AU)

• Processo FAPESP: 18/09158-0 - Prolil oligopeptidase: estrutura-atividade e secreção
• Beneficiário: Vitor Marcelo Silveira Bueno Brandão de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/01487-7 - Nanopartículas de ouro associadas à cisteíno-proteases derivadas de Bromelaína: caracterização estrutural e ação colagenolítica
• Beneficiário: Marcelo Yudi Icimoto
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/04352-0 - Contribuição da interação entre a caveolina-1 e as enzimas GTP ciclohidrolase I e sintase de óxido nítrico ao longo da progressão do melanoma
• Beneficiário: Fabiana Henriques Machado de Melo
• Modalidade de apoio: Auxílio à Pesquisa - Regular