Nrf2-mediated modulation of ROS homeostasis is associated with NF-κB activation and glioblastoma progression

Treatment alternatives for patients diagnosed with glioblastoma remain quite restricted, and the overall outlook for these individuals remains unfavorable. Nuclear factor E2-related factor 2 (Nrf2) serves as a crucial regulatory component within the antioxidant stress response pathway and is implicated in numerous human malignancies. However, the precise role and potential molecular mechanisms of Nrf2 in the context of glioblastoma have yet to be thoroughly clarified.

By integrating glioblastoma sample cohorts from public databases such as TCGA and CGGA, we systematically analyzed the expression characteristics of Nrf2 and its clinical significance. We constructed Nrf2 knockdown and overexpression models in U251 and LN229 glioblastoma cell lines using lentiviral vectors. Functional impacts were assessed through proliferation, migration, and invasion assays. Mechanistic insights were gained by measuring intracellular ROS levels (using DCFH-DA probe and flow cytometry), examining NF-κB pathway activation (Western blot for p65 and p-p65), and assessing co-localization (immunofluorescence).

Nrf2 is highly expressed in glioblastoma and associated with poor prognosis. Knockdown of Nrf2 inhibited, while its overexpression promoted, the proliferation, migration, and invasion of glioblastoma cells in vitro and tumor growth in vivo. Notably, Nrf2 overexpression was accompanied by lower intracellular ROS levels, increased nuclear translocation of NF-κB p65, and enhanced phosphorylation of p65. Conversely, Nrf2 knockdown elevated ROS and reduced NF-κB activation.

Our data indicate that Nrf2 is upregulated in glioblastoma and correlates with poor prognosis. The findings support a model in which Nrf2, through its modulation of ROS homeostasis, may foster a cellular milieu permissive for sustained NF-κB activation, thereby contributing to glioblastoma progression. This proposed axis highlights potential therapeutic targets for this aggressive malignancy.