Targeting NRF2-regulated polyamine and glutathione metabolism enhances chemotherapy efficacy in colorectal cancer based on KRAS status

Metabolic reprogramming is a hallmark of colorectal cancer and is strongly influenced by oncogenic KRAS mutations, which contributes to reduced drug responsiveness and poor clinical outcomes. Inducing ferroptosis-a form of iron-dependent, lipid peroxidation-driven cell death-has emerged as a promising strategy to augment chemotherapy response by disrupting this adaptive metabolic state. However, the interplay between KRAS-specific metabolism and ferroptosis-induced drug sensitivity remains incompletely understood and could enable precision therapeutic interventions. In our study, we integrated public datasets and in vitro experiments to investigate the drug combination effect and how the metabolism will be altered. We first utilized drug sensitivity data from CRC cell lines, and we found that drug response varied by KRAS status and engaged distinct ferroptotic dependencies: KRAS-mutant cells showed increased reliance on iron-handling genes ( FTH1, FTL, SLC11A2 ), whereas KRAS wild-type cells were more vulnerable to disruption of GPX4-mediated antioxidant defense. Given that NRF2 coordinates ferroptosis through both iron homeostasis and antioxidant responses, pharmacologic inhibition of NRF2 using Brusatol across four CRC cell lines (representing wild type, KRAS G12D, and KRAS G13D) markedly enhanced chemotherapy efficacy, with the strongest effect observed in KRAS G12D lines, followed by wild-type cells. Regarding non-targeted metabolomics analysis, co-treatment with Brusatol and Oxaliplatin or 5-Fluorouracil rendered dysregulated pathways that fuel cancer growth and progression, including methionine cycle, nucleotide synthesis as well as energy metabolism only in wild-type cells and KRAS G12D mutant which accounted for improved inhibitory effect. Moreover, distinctive alterations depending on KRAS mutation were observed under this combination therapy, manifesting KRAS mutants (comprising KRAS G12D and KRAS G13D ) demonstrated an blockage of polyamine catabolism with extremely decreased acetylspermine, whereas wild-type cells suffered elevated oxidative stress with severe GSH exhaustion and GSH/GSSG ratio reduction. In light of clinical unavailability of Brusatol, we successfully repositioned several clinically viable antineoplastic drugs and a panel of therapeutic agents under preclinical status for emerging tumor combat utilizing a transcriptional-based silico drug repurposing approach. Our findings highlighted NRF2 deprivation-mediated polyamine metabolism as a potential target for chemosensitivity and provided a clinically-approved therapeutic option in KRAS G12D CRC, brightening the path for targeted therapy and translation medicine.