Project description:This study aimed to elucidate the relationships between NRF2 and disease progression and provide insight into NRF2-mediated cancer progression/tumorigenesis by identifying novel genes and pathways regulated by NRF2 in A549 NSCLC cells
Project description:KEAP1 overexpressed and NRF2 siRNA knockdown A549 NSCLC cells were used to identify downstream genes of NRF2 pathway separately and by combinatorial analysis. We used triplicate microarrays of transfected A549 cells with mKeap1-GFP for overexpression, siRNAs targeting NRF2 for knockdown and siGFP as control respectively. As a result, we identified several genes which are involved in cancer metabolic functions in these cells. We used microarrays to identify the gene downregulated in both KEAP1 overexpressed and NRF2 siRNA knockdown A549 NSCLC cells and found a subset of downregulated genes which are involved in metabolic functions.
Project description:To elucidate the mechanisms by which Nrf2 regulates cell growth, we performed global gene expression profiling of A549 lung cancer cells with knockdown of Nrf2. Gene networks associated with carbohydrate metabolism and drug metabolism were significantly downregulated in Nrf2-depleted A549 cells. Gene Set Enrichment Analysis revealed significant enrichment of genes associated with carbohydrate catabolic processes, positive regulation of metabolic processes, PPP, and arachidonic acid metabolism. In summary, this analysis revealed that Nrf2 positively regulates transcription of genes that play key roles in central carbon metabolism. A549 cells were transfected with non targeting NS siRNA or siRNA targeting Nrf2. Mock transfected A549 cells were treated with transfection reagent alone. We had 3 biological replicates for each of the 3 groups. Ninty six hours post transfection, cells were lysed and total RNA was isolated.
Project description:To examine the role of NRF2 in accelerating cell proliferation and to identify the target genes responsible for this function, transcriptome analysis was performed using A549 cells, in which NRF2 is constitutively activated. NRF2 was knocked down by siRNA against NRF2, and the gene expression profile was compared with that of A549 cells treated with control siRNA. To exclude off-target effects, three different siRNAs against NRF2 was independently applied. NRF2 siRNA or control siRNA was transfected into A549 cells. Cells were harvested 24 hours after transfection, and total RNA was purified.
Project description:Cisplatin resistance is a major cause of poor prognosis in non-small cell lung cancer (NSCLC). Cisplatin-induced lung cancer cell death is associated with ferroptosis, a type of recently identified programmed cell death. Nrf2 is a critical component of the antioxidant system, and its pro-tumorigenic activity in lung cancer has been extensively studied. However, the role of Nrf2 in cisplatin-induced ferroptosis and drug resistance remains elusive. Here, we demonstrate that cisplatin treatment induced ferroptosis in parental A549 lung adenocarcinoma cells, and that this effect was significantly reduced in cisplatin-resistant A549/DDP cells. Knocking down Nrf2 sensitized A549/DDP cells to cisplatin-induced cytotoxicity by enhancing ferroptosis. Moreover, we demonstrated that Nrf2 promotes the expression of HMOX1, and the Nrf2-HMOX1 pathway is critical in mediating the anti-ferroptotic function. Additionally, immunohistochemical analysis of NSCLC specimens indicated that the Nrf2 expression was correlated with HMOX1, and high levels of Nrf2 and HMOX1 were associated with poor patient survival. These findings suggest that the HMOX1-Nrf2 pathway significantly influences treatment outcomes in NSCLC. Ultimately, we demonstrated that treatment with Nrf2 inhibitor ML385 promoted ferroptosis by inhibiting the Nrf2-HMOX1 pathway, restoring cisplatin sensitivity in drug-resistant cells. Our findings provide insights into the mechanism underlying cisplatin resistance and suggests that targeting the Nrf2-HMOX1 pathway enhances cisplatin-induced ferroptosis and improves NSCLC treatment outcomes.