Abstract PS2-12-11: Tgfβ-associated transcription factors induce metabolic and chromatin remodeling in breast cancer cells

Abstract The transforming growth factor β (TGFβ) family encodes pleiotropic cytokines that modulate cellular identity, primarily through the epithelial-mesenchymal transition (EMT) and the promotion of cancer stem cell populations, which accounts for elevated tumor heterogeneity. In breast cancer cells, such heterogeneity can be manifested at both transcriptional and epigenetic levels, with direct implications for metabolic rewiring. Using CRISPR/Cas9 gene editing technology, we ablated the EMT-related transcription factor SNAI2 in triple-negative breast cancer cells. Whole-transcriptome profiling revealed significant downregulation in cell cycle-related processes associated with the induction of apoptosis and cell death signatures. Strikingly, knockout (KO) cells exhibited significant alterations in various genes involved in central metabolic pathways, including oxidative phosphorylation, fatty acid metabolism and mTOR signaling. Functional analyses of mitochondrial respiratory activities showed enhanced complex I and complex II activities as well as increased ATP-linked, maximum, and reserve respiratory capacities in SNAI2 KO cells. Feul-dependence studies indicated a significant reduction in fatty acid dependence, attributed to the account of pyruvate metabolism, while glutamiolysis and glycolytic metabolism remained unchanged. The KO cells exhibited elevated mitochondrial density, accompanied by accumulation of intracellular and mitochondrial reactive oxygen species. Phenotypically, the KO cells presented an intermediate epithelial-mesenchymal state with decreased proliferation capacity and migration potential. Additionally, the KO cells showed enhanced sensitivity to the CDK4/6 inhibitor palbociclib, compared to parental cells. Seminal studies in various breast cancer models have revealed the potency of TGFβ in promoting cell resistance to palbociclib through transcriptional modulation of EMT factors, including SNAI2, and subsequent metabolic remodeling. Therefore, the present study demonstrates the pivotal role of SNAI2 in mediating transcriptional and metabolic rewiring, leading to increased cancer heterogeneity. Citation Format: M. M. Ali, C. Tsirigoti, H. Yasmin, S. S. Ali, A. Moustakas. Tgfβ-associated transcription factors induce metabolic and chromatin remodeling in breast cancer cells [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS2-12-11.