Temozolomide resistance mechanisms: unveiling the role of translesion DNA polymerase kappa in glioblastoma spheroids in vitro

Author(s)

Ribeiro, Diego Luis ; Latancia, Marcela Teatin ; de Souza, Izadora ; Ariwoola, Abu-Bakr Adetayo ; Mendes, Davi ; Rocha, Clarissa Ribeiro Reily ; Lengert, Andre Van Helvoort ; Menck, Carlos Frederico Martins

• Document type: Journal article
• Source: BIOSCIENCE REPORTS; v. 44, n. 5, p. 18-pg., 2024-05-29.

Abstract

Temozolomide (TMZ) is the leading therapeutic agent for combating Glioblastoma Multiforme (GBM). Nonetheless, the persistence of chemotherapy-resistant GBM cells remains an ongoing challenge, attributed to various factors, including the translesion synthesis (TLS) mechanism. TLS enables tumor cells to endure genomic damage by utilizing specialized DNA polymerases to bypass DNA lesions. Specifically, TLS polymerase Kappa (Pol'() has been implicated in facilitating DNA damage tolerance against TMZ-induced damage, contributing to a worse prognosis in GBM patients. To better understand the roles of Pol'( in TMZ resistance, we conducted a comprehensive assessment of the cytotoxic, antiproliferative, antimetastatic, and genotoxic effects of TMZ on GBM (U251MG) wild-type (WTE) and TLS Pol'( knockout (KO) cells, cultivated as three-dimensional (3D) tumor spheroids in vitro. Initial results revealed that TMZ: (i) induces reductions in GBM spheroid diameter (10-200 (<= 25 mu M) and promotes cell cycle arrest (G2/M phase) in Pol'( KO spheroids when compared with WTE counterparts. Furthermore, Pol'( KO spheroids exhibit elevated levels of cell death (Caspase 3/7) and display greater genotoxicity (53BP1) than WTE following TMZ exposure. Concerning antimetastatic effects, TMZ impedes invadopodia (3D invasion) more effectively in Pol'( KO than in WTE spheroids. Collectively, the results suggest that TLS Pol'( plays a vital role in the survival, cell death, genotoxicity, and metastatic potential of GBM spheroids in vitro when subjected to TMZ treatment. While the precise mechanisms underpinning this resistance remain elusive, TLS Pol'( emerges as a potential therapeutic target for GBM patients. (AU)

• FAPESP's process: 22/03130-1 - The role of autophagy and NRF2 pathways in ferroptosis
• Grantee: Clarissa Ribeiro Reily Rocha
• Support Opportunities: Research Grants - Initial Project
• FAPESP's process: 21/11597-4 - Analysis of the role of NRF2 in ferroptosis modulation in chemotherapy-resistant tumor cell lines
• Grantee: Izadora de Souza
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 20/02836-2 - Mechanisms of Glioblastoma resistance to antitumoral temozolomide in cells cultured as three-dimensional (3D) multicellular tumor spheroids in vitro: the role of translesion synthesis polymerases
• Grantee: Diego Luis Ribeiro
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/08028-1 - CEGH-CEL - Human Genome and Stem Cell Research Center
• Grantee: Mayana Zatz
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 19/19435-3 - The role of DNA damage and mitochondrial function in vascular, immune and neurological ageing (DNA MoVINg)
• Grantee: Carlos Frederico Martins Menck
• Support Opportunities: Research Projects - Thematic Grants