Abstract:
Glioblastoma Multiforme (GBM), constituting a predominant subtype of malignant brain cancers,
presents a crucial challenge due to poor prognosis, the blood-brain barrier,intra-tumoral
heterogeneity , and glioblastoma stem cells, hindering efficient therapeutic strategies. This study
employs human recombinant arginase ([HuArgI(Co)-PEG5000]) as a targeted therapeutic agent to
induce arginine deprivation in fully and partially auxotrophic GBM cells. The objective is to
investigate the mechanism of arginine deprivation involved in arginine deprivation induced-cell
death in GBM cells, and to investigative the potential link to ferroptosis. Our results reveal that
[HuArgI(Co)-PEG5000] activated autophagy and induces cytotoxicity in GBM, leading to ROS
accumulation. This was mitigated through the use ROS scavenging agents N-acetyl-l-cysteine
(NAC). Examination of key regulatory proteins involved in iron homeostasis (NCOA4 and FTH1)
and oxidative stress defenses (and GPX4) suggests altered iron distribution impairing the
antioxidant system in treated cells. This indicates that ferroptosis is downstream of autophagy
mediated cell death. In summary, our results emphasize that the depletion of arginine through
[HuArgI(Co)-PEG5000] treatment triggers elevated production of ROS, lipid peroxidation, and
perturbation of iron metabolism and antioxidant pathways, this suggests that arginine deprivation
induced by [HuArgI(Co)- PEG5000] in GBM causes death by ferroptosis, an autophagy-mediated
cell death. Understanding these mechanisms holds implications for developing targeted therapies
not only for GBM but also for other cancer types.
