Project description:Brain metastasis is one of the lethal causes of breast cancer. Here we identified an altered lipid metabolism state to be associated with brain metastatic potential of breast cancer cell lines. To investigate the mechanism, we knocked out genes mediating this altered state and examined transcriptomic changes. The results revealed that these genes confer cells a state with increased lipid and cholesterol biosynthesis and that resembles the lipid metabolite state seen in the brain. These findings revealed an unappreciated machinery that cancer cells adopt for their increased adaptability to the brain microenvironment.
Project description:Human cells produce thousands of lipids that impact biological processes in ways we are only starting to characterize. The cellular composition in lipids changes during differentiation and also varies across individual cells of the same type. Yet, whether and how cell-to-cell differences in lipid composition affect cell phenotypes remain unknown. Here we have measured the lipidomes and transcriptomes of individual human dermal fibroblasts by coupling high-resolution mass spectrometry imaging to single-cell transcriptomics. We find that the cell-to-cell variation of specific lipid metabolic pathways contributes to the establishment of cell states involved in the organization of skin architecture. In fact, sphingolipid composition defines fibroblast subpopulations and its metabolic rewiring drives cell state transitions. These data uncover a role for cell-to-cell lipid heterogeneity in the determination of cell states and reveal a new regulatory component to the self-organization of multicellular systems.
Project description:CDK4/6 inhibition is the standard of care for estrogen receptor positive (ER+) breast cancer, although cytostasis is frequently observed, and new treatment strategies that enhance efficacy are required. We performed a genome-wide CRISPR screen to identify genetic determinants of CDK4/6 inhibitors sensitivity. Multiple genes involved in oxidative stress and ferroptosis modulated palbociclib sensitivity. Depletion or inhibition of GPX4 increased sensitivity to palbociclib in ER+ breast cancer models, and sensitised triple negative breast cancer models to palbociclib, with GPX4 null xenografts being highly sensitive to palbociclib. Palbociclib induced oxidative stress and disordered lipid metabolism with lipid peroxidation, leading to a ferroptosis-sensitive state. Lipid peroxidation relied on a peroxisome AGPAT3-dependent pathway in ER+ breast cancer models, rather than the classical ACSL4 pathway. Our data demonstrate that CDK4/6 inhibition creates vulnerability to ferroptosis that could be exploited through combination with GPX4 inhibitors, enhancing sensitivity to CDK4/6 inhibition in breast cancer.
Project description:We have generated and employed reversible and irreversible EMT models of murine breast cancer cells to identify the key players establishing cell state transitions during a reversible and an irreversible EMT. We demonstrate that the Mbd3/NuRD complex, involving histone deacetylases (HDACs) and Tet2 hydroxylase, acts as an epigenetic block in epithelial-mesenchymal plasticity. These epigenetic modifiers keep breast cancer cells in a stable mesenchymal state, and their pharmacological inhibition or genetic ablation leads to a mesenchymal-epithelial transition (MET) and represses primary tumor growth and metastasis formation of highly aggressive, mesenchymal breast cancer cells.
Project description:Trastuzumab therapy in HER2+ breast cancer patients have mixed success owing to acquired resistance to therapy. In this study, we investigate the cellular mechanisms underlying acquired resistance using -sensitive and -resistant cancer cells (BT474 and BT474R) treated with endogenous ligands EGF and HRG, across time. Our measurements probe early receptor organization through microscopy, signaling events through multi-omic measurements and assess the cellular energetic state through mitochondrial measurements. Our integrative analyses of these multimodal measurements highlight differential mechanisms in both cell lines in response to ligands. In BT474, an active PI3K-AKT-mTORC1 signaling contributes to an active mitochondrial bioenergetic state (glycolysis and lipid metabolism) for both ligands EGF and HRG. A HIF1A mediated increase in cellular bioenergetics is also seen. In BT474R, there is a ligand-dependent activation of signaling cascades. In EGF treated BT474R, an EGFR driven IRF1/STAT1/STAT2 activation with likely impact on cellular bioenergetics is seen, whilst an AR mediated alteration of lipid metabolism is pronounced after HRG treatment.
Project description:The current view of cellular transformation and cancer progression supports the notion that cancer cells must reprogram their metabolism in order to survive and progress in different microenvironments. Master co-regulators of metabolism orchestrate the modulation of multiple metabolic pathways through transcriptional programs, and hence constitute a probabilistically parsimonious mechanism for general metabolic rewiring. Here we show that the transcriptional co-activator PGC1α suppresses prostate cancer progression and metastasis. A metabolic co-regulator data mining analysis unveiled that PGC1α is consistently down-regulated in multiple prostate cancer patient datasets and its alteration is associated with reduced disease-free survival and metastasis. Genetically engineered mouse model studies revealed that compound prostate epithelium-specific deletion of Pgc1a and Pten promotes prostate cancer progression and metastasis, whereas, conversely, PGC1α expression in cell lines inhibits the pre-existing metastatic capacity. Through the application of integrative metabolomics and transcriptomics we demonstrate that PGC1α expression in prostate cancer is sufficient to elicit a global metabolic rewiring that opposes cell growth, consisting of sustained oxidative metabolism at the expense of anabolism. This metabolic program is regulated downstream the Oestrogen-related receptor alpha (ERRα), and PGC1α mutants lacking ERRα activation capacity lack metabolic rewiring capacity and metastasissuppressive function. Importantly, an ERRα signature in prostate cancer recapitulates the prognostic features of PGC1A. Our findings uncover an unprecedented causal contribution of PGC1α to the metabolic switch in prostate cancer and to the suppression of metastatic dissemination. Total RNA was isolated from prostate cancer cell line PC3 expressing or not PGC1a (for induction, cells were treated with doxycycline for 2 passages)
Project description:To characterize Homologous recombination deficiency (BRCAness) in triple-negative breast cancer PDX models genomic signature was utilized. After normalization using Genotyping Console we obtained absolute copy number profiles using the GAP software (Popova et al, Genome Biol, 2009). The number of Large-scale State Transitions (LSTs) was used to annotate PDX as BRCAness or not (Popova et al, Cancer Res 2012).
Project description:To characterize Homologous recombination deficiency (BRCAness) in triple-negative breast cancer PDX models genomic signature was utilized. After normalization using ChAS we obtained absolute copy number profiles using the GAP software (Popova et al, Genome Biol, 2009). The number of Large-scale State Transitions (LSTs) was used to annotate PDX as BRCAness or not (Popova et al, Cancer Res 2012).
Project description:Changes in the three-dimensional (3D) structure of the genome are an emerging hallmark of cancer. However, little is known about the rewiring of the 3D chromatin landscape during cancer progression to a chemotherapy-resistant state. We utilized a patient-derived xenograft (PDX) mouse model of triple-negative breast cancer (UCD52) to characterize changes in the 3D structure between the primary tumor and carboplatin-resistant state. Systematic integration of matched chromatin conformation capture (Hi-C), RNA-seq, and whole-genome sequencing data revealed a widespread increase in short-range (<2Mb) interactions with the corresponding increase in chromatin looping and topologically associating domain (TAD) formation, chromatin state switching into a more active state, large-scale deletions, amplification of ATP-binding cassette (ABC) transporters and nearly complete shutdown of drug metabolism pathways. Rewiring of the 3D genome was associated with TP53, TP63, BATF, FOS-JUN family of transcription factors and led to activation of many aggressiveness-, metastasis- and other cancer-related pathways. Transcriptome changes suggest the role of downregulated protein-coding genes and upregulated long-noncoding RNAs in drug resistance. Integrative analysis confirmed increased ribosome biogenesis and oxidative phosphorylation, suggesting the role of mitochondrial metabolic processes. Our results highlight that 3D genome remodeling may be a key mechanism underlying drug resistance.
Project description:Changes in the three-dimensional (3D) structure of the genome are an emerging hallmark of cancer. However, little is known about the rewiring of the 3D chromatin landscape during cancer progression to a chemotherapy-resistant state. We utilized a patient-derived xenograft (PDX) mouse model of triple-negative breast cancer (UCD52) to characterize changes in the 3D structure between the primary tumor and carboplatin-resistant state. Systematic integration of matched chromatin conformation capture (Hi-C), RNA-seq, and whole-genome sequencing data revealed a widespread increase in short-range (<2Mb) interactions with the corresponding increase in chromatin looping and topologically associating domain (TAD) formation, chromatin state switching into a more active state, large-scale deletions, amplification of ATP-binding cassette (ABC) transporters and nearly complete shutdown of drug metabolism pathways. Rewiring of the 3D genome was associated with TP53, TP63, BATF, FOS-JUN family of transcription factors and led to activation of many aggressiveness-, metastasis- and other cancer-related pathways. Transcriptome changes suggest the role of downregulated protein-coding genes and upregulated long-noncoding RNAs in drug resistance. Integrative analysis confirmed increased ribosome biogenesis and oxidative phosphorylation, suggesting the role of mitochondrial metabolic processes. Our results highlight that 3D genome remodeling may be a key mechanism underlying drug resistance.