Study on the Mechanism of FOXA2 Activation on Glutathione Metabolic Reprogramming Mediated by ETV4 Transcription to Facilitate Colorectal Cancer Malignant Progression

Abstract

The metabolic imbalance of glutathione (GSH) has been widely recognized in most cancers, but the specific molecular mechanism of GSH metabolic regulation in the malignant progression of colorectal cancer (CRC) is unexplored. The objective of our project is to elucidate whether ETV4 affects the malignant progression of CRC through GSH metabolic reprogramming. Bioinformatics and molecular experiments measured the expression of ETV4 in CRC, and in vitro experiments explored the impact of ETV4 on CRC malignant progression. The Kyoto Encyclopedia of Genes and Genomes (KEGG) identified the pathway of ETV4 enrichment. The bioinformatics approach identified FOXA2 as an upstream regulatory factor of ETV4. The dual-luciferase assay, chromatin immunoprecipitation (ChIP) and co-immunoprecipitation (Co-IP) experiment verified the binding relationship between ETV4 and FOXA2. Cell viability, migration, and invasion abilities were determined by conducting CCK-8, wound healing, and Transwell assays, respectively. The expression levels of N-cadherin, E-cadherin, and vimentin were determined by utilizing immunofluorescence (IF). Metabolism-related enzymes GCLM, GCLC, and GSTP1 levels were detected to evaluate the GSH metabolism level by analyzing the GSH/GSSG ratio. In vivo experiments were performed to explore the effect of FOXA2/ETV4 on CRC progression, and the expression of related proteins was detected by western blot. ETV4 was highly expressed in CRC. Knocking down ETV4 suppressed CRC cell viability, migration, invasion, and epithelial-mesenchymal transition (EMT) progression in vitro. ETV4 was abundant in the GSH metabolic pathway, and overexpression of ETV4 facilitated CRC malignant progression through activation of the GSH metabolism. In addition, in vitro cellular experiments and in vivo experiments in nude mice confirmed that FOXA2 transcriptionally activated ETV4. Knocking down FOXA2 repressed the malignant phenotype of CRC cells by suppressing GSH metabolism. These effects were reversed by overexpressing ETV4. Our results indicated that FOXA2 transcriptionally activates ETV4 to facilitate CRC malignant progression by modulating the GSH metabolic pathway. Targeting the FOXA2/ETV4 axis or GSH metabolism may be an effective approach for CRC treatment.

Keywords: Colorectal cancer; ETV4; FOXA2; Glutathione metabolism; Malignant progression.