Diversity of oxidative stress and senescence phenotypes induced by chemotherapeutic agents in HUVECs.

Chemotherapy-induced endothelial cell senescence impacts tumor angiogenesis and therapy outcomes. While senescence can suppress tumorigenesis, it may also promote chronic inflammation and vascular toxicity. This study investigates how different chemotherapeutic agents induce senescence in human umbilical vein endothelial cells (HUVECs) and explores the roles of reactive oxygen species (ROS) and ataxia telangiectasia mutated (ATM) kinase. HUVECs were treated with DNA crosslinkers (doxorubicin, mitomycin C), topoisomerase inhibitors (etoposide, camptothecin), and methotrexate (MTX). Senescence was assessed via senescence-associated β-galactosidase (SA-β-gal) staining, senescence-associated secretory phenotype related factors, Phalloidin staining, immunofluorescence (p53, Ki67, 53BP1, γH2AX), mitochondrial morphology, ROS measurement, and transcriptomic sequencing. ROS scavenger Mito-Q and ATM inhibitor KU55933 were co-administered to evaluate their modulatory effects. SA-β-gal staining demonstrated that all agents induced senescence, with etoposide being the most potent (80% SA-β-gal-positive cells) and methotrexate the weakest (40%). DNA damage markers (53BP1, γH2AX) and ROS levels increased significantly, accompanied by mitochondrial fragmentation, reduced Ki67, and increased cell morphology. Furthermore, Mito-Q alleviated methotrexate-induced senescence but had no effect on other agents. ATM inhibition did not demonstrate an effect across all treatments in this study. Transcriptomic analysis revealed the p53 signaling pathway as a pivotal molecular determinant in chemotherapy-induced cellular senescence. MTX appeared mechanistically linked to TNF-mediated signaling cascades. Chemotherapeutic agents triggered endothelial senescence via DNA damage and ROS accumulation, with heterogeneity in potency and mechanisms. ROS scavengers may mitigate methotrexate-associated vascular toxicity, and targeting ROS could enhance chemotherapy safety by preserving endothelial function.