Crosstalk between FTH1 and PYCR1 dysregulates proline metabolism and mediates cell growth in KRAS-mutant pancreatic cancer cells

Abstract

Ferritin, comprising heavy (FTH1) and light (FTL) chains, is the main iron storage protein, and pancreatic cancer patients exhibit elevated serum ferritin levels. Specifically, higher ferritin levels are correlated with poorer pancreatic ductal adenocarcinoma (PDAC) prognosis; however, the underlying mechanism and metabolic programming of ferritin involved in KRAS-mutant PDAC progression remain unclear. Here, we observed a direct correlation between FTH1 expression and cell viability and clonogenicity in KRAS-mutant PDAC cell lines as well as with in vivo tumor growth through the control of proline metabolism. Our investigation highlights the intricate relationship between FTH1 and pyrroline-5-carboxylate reductase 1 (PYCR1), a crucial mitochondrial enzyme facilitating the glutamate-to-proline conversion, underscoring its impact on proline metabolic imbalance in KRAS-mutant PDAC. This regulation is further reversed by miR-5000-3p, whose dysregulation results in the disruption of proline metabolism, thereby accentuating the progression of KRAS-mutant PDAC. Additionally, our study demonstrated that deferasirox, an oral iron chelator, significantly diminishes cell viability and tumor growth in KRAS-mutant PDAC by targeting FTH1-mediated pathways and altering the PYCR1/PRODH expression ratio. These findings underscore the novel role of FTH1 in proline metabolism and its potential as a target for PDAC therapy development. Iron storage in our body is mainly controlled by a protein named ferritin, which reflects the amount of stored iron through its blood levels. Low ferritin levels usually suggest iron-deficiency anemia, while high levels can indicate inflammation and hinting at ferritin’s potential as a cancer indicator. In this study, scientists focused on pancreatic cancer, notorious for its low survival rates and limited treatment options. They examined the expression of different ferritin components and their link with the KRAS mutation, a common characteristic in pancreatic cancer that promotes tumor growth. The main discovery is that high FTH1 expression is associated with worse survival in pancreatic cancer patients, suggesting that targeting FTH1 could be a promising treatment for this aggressive cancer. This study enhances our knowledge of the molecular processes driving pancreatic cancer and opens new paths for targeted treatments. This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author.