Small molecular weight polyfluoroalkyl phosphonates induce ROS-mediated cytotoxicity in glioblastoma cells: a molecular mechanism study

Glioblastoma (GBM) is an aggressive brain tumour with limited treatment options and poor patient survival, largely due to the blood-brain barrier (BBB) restricting effective drug delivery. In this study, we focused on two small molecular weight polyfluoroalkyl phosphonates, ZOT₅-1-Me and ZOT₅-1-Et, designed to permeate the BBB. Comprehensive in vitro analyses using U-87 MG cells and a panel of glioma cell lines revealed that both compounds exhibit potent cytostatic and cytotoxic activities. Mechanistically, they induce reactive oxygen species (ROS) production, triggering both intrinsic and extrinsic apoptotic pathways via caspase-dependent and caspase-independent mechanisms. Additionally, ZOT₅-1-Me and ZOT₅-1-Et induced DNA damage, including single-strand breaks and alkali-labile sites. Notably, ZOT₅-1-Me also caused significant DNA double-strand breaks and impaired DNA repair. Furthermore, both compounds exhibited antiproliferative effects by inducing cell cycle arrest in the S phase and activating p53-p21 signalling pathway. Pre-treatment with the ROS scavenger N-acetyl-L-cysteine (NAC) effectively abrogated these cytotoxic effects, underscoring the central role of oxidative stress in mediating the compounds' antitumour activity. Collectively, our findings suggest that these polyfluoroalkyl phosphonates represent promising ROS-modulating chemotherapeutic candidates with unique mechanisms of action that may complement existing GBM treatment strategies.