Abstract 270: Metabolic rewiring and metastatic potential in STK11-null lung adenocarcinoma

Abstract

Non-small cell lung adenocarcinomas with concurrent oncogenic KRAS and SKT11 loss-of-function mutations represent an aggressive subtype that is characterized, in part, by increased metastasis and enhanced dependence on glutamine metabolism. The purpose of this study was to elucidate the metabolic rewiring of STK11-null KRAS-driven lung adenocarcinoma cells and determine how such altered metabolism may promote metastasis. Both parental and ΔSTK11 cells, generated via CRISPR-Cas9, were assessed for metabolic flux and measures of metastatic potential at baseline, and when deprived of exogenous glutamine. Seahorse analysis revealed a “metabolically exhausted” mitochondrial phenotype in ΔSTK11 cells at baseline. Upon exogenous glutamine deprivation, both ΔSTK11 and parental cells similarly decreased mitochondrial respiration, however, through the employment of RNA sequencing and heavy carbon labeling, we demonstrate an upregulation of the hexosamine biosynthetic pathway (HBP) in ΔSTK11 cells. Moreover, we observed an increase in global O-GlcNAcylation, the product of the HBP, in ΔSTK11 cells. The HBP is an offshoot of glycolysis/gluconeogenesis that serves as a central hub to regulate many cancer fitness pathways via O-GlcNAcylation, and it has been established that cancer cells upregulate the HBP resulting in activation of proteins involved in promoting metastasis. To assess transcriptional characteristics of metastatic spread, KEGG pathway analysis was performed on transcriptomic data obtained from parental vs ΔSTK11 cells subjected to glutamine deprivation and revealed significant upregulation of NFkB and MAPK signaling in ΔSTK11 cells. Additionally, EMT markers downstream of these pathways, such as SNAI2 and ZEB1, were upregulated in ΔSTK11 cells. Trypan Blue staining was used as a preliminary method to measure anoikis resistance, an additional characteristic of metastatic potential. Results revealed a significant increase in live detached cells upon glutamine deprivation-induced detachment in ΔSTK11 cells. Correspondingly, differential gene expression indicated significant upregulation of BCL2A1, an anti-apoptotic protein, in ΔSTK11 cells following glutamine deprivation. Future studies aim to further clarify the altered metabolic profile of ΔSTK11 lung adenocarcinoma cells to identify the mechanism(s) by which such metabolic rewiring drives metastatic progression. In conclusion, this work reveals novel findings regarding the molecular mechanisms altered downstream of STK11-loss that influence glutamine metabolism and enhanced metastasis in KRAS-driven lung adenocarcinomas. Citation Format: Shannon M. Prior, Sean M. Lenahan, Hailey M. Sarausky, David J. Seward, Paula B. Deming. Metabolic rewiring and metastatic potential in STK11-null lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 270.