Project description:We have used a conditional mouse model to investigate the role of Zbtb11 specifically in hematopoiesis. When Zbtb11 was deleted in the hematopoietic compartment, embryos died at embryonic day E18.5 with hematopoietic failure. Zbtb11 hematopoietic knockout (Zbtb11hKO) hematopoietic stem cells (HSCs) were overabundantly specified at E14.5 through E17.5 compared to controls. Overspecification was accompanied by loss of stemness, inability to differentiate into committed progenitors and mature lineages in fetal liver, failure to seed fetal bone marrow and total hematopoietic failure. Zbtb11hKO HSCs did not proliferate in vitro and were constrained in cell cycle progression, demonstrating a cell-intrinsic role for Zbtb11 in proliferation and cell cycle regulation in mammalian HSCs. scRNAseq analysis identified Zbtb11-deficient HSCs were underrepresented in an erythroid-primed subpopulation and showed downregulation of oxidative phosphorylation (OXPHOS) pathways and dysregulation of genes associated with the hematopoietic niche. We have identified a cell-intrinsic requirement for Zbtb11-mediated gene regulatory networks in sustaining a pool of maturation-capable hematopoietic stem and progenitor cells.
Project description:Hematopoiesis produces diverse blood cell lineages to meet the basal needs and sudden demands of injury or infection. A rapid response to such challenges requires the expansion of specific lineages and a prompt return to balanced steady-state levels, necessitating tightly coordinated regulation. Previously we identified a requirement for the zinc finger and broad complex, tramtrak, bric-a-brac domain-containing 11 (ZBTB11) transcription factor in definitive hematopoiesis using a forward genetic screen for zebrafish myeloid mutants. To understand its relevance to mammalian systems, we extended these studies to mice. When Zbtb11 was deleted in the hematopoietic compartment, embryos died at embryonic day (E) 18.5 with hematopoietic failure. Zbtb11 hematopoietic knockout (Zbtb11hKO) hematopoietic stem cells (HSCs) were overabundantly specified from E14.5 to E17.5 compared with those in controls. Overspecification was accompanied by loss of stemness, inability to differentiate into committed progenitors and mature lineages in the fetal liver, failure to seed fetal bone marrow, and total hematopoietic failure. The Zbtb11hKO HSCs did not proliferate in vitro and were constrained in cell cycle progression, demonstrating the cell-intrinsic role of Zbtb11 in proliferation and cell cycle regulation in mammalian HSCs. Single-cell RNA sequencing analysis identified that Zbtb11-deficient HSCs were underrepresented in an erythroid-primed subpopulation and showed downregulation of oxidative phosphorylation pathways and dysregulation of genes associated with the hematopoietic niche. We identified a cell-intrinsic requirement for Zbtb11-mediated gene regulatory networks in sustaining a pool of maturation-capable HSCs and progenitor cells.
Project description:Zbtb11 is an uncharacterised transcription factor that is conserved in vertebrates. Mutations in its human gene cause a form of inherited intellectual disablity, while in zebrafish Zbtb11 mutations lead to impaired hematopoesis and neruonal development. We used a combination of functional genomics approaches to determine its functions. To determine the genomic Zbtb11 binding locations, we carried out ChIP-seq using FLAG antibodies in a cell line with the endogenous Zbtb11 N-terminally tagged with FLAG (Zbtb11 FLAG/FLAG), as well as using an anti-Zbtb11 antibody in a wild type line. To determine the genes regulated by Zbtb11 we generated an inducible KO line (Zbtb11 lox/lox, Rosa26 ERt2-Cre) that allows the rapid depletion of Zbtb11 upon treatment with 4-hydroxytamoxyfen (4OHT). We treated Zbtb11 lox/lox, Rosa26 ERt2-Cre cells either with 4OHT (Zbtb11 KO) or ethanol (EtOH) as control, and subsequently performed directional RNA-seq from samples collected 48 hours post-treatment. As control for the effect of 4OHT on gene expression, we also compared Zbtb11 KO cells to wild type cells treated with 4OHT. The two ChIP-seq approaches showed very good overlap and allowed us to generate a set of high-confidence Zbtb11 binding sites common to both peak sets. We found Zbtb11 preferentially binds to a subset of house-keeping genes among which genes encoding proteins with mitochondrial functions are enriched. Upon Zbtb11 deletion, 154 genes changed expression 48 hours later, the vast majority of them down-regulated. Integration of ChIP-seq and RNA-seq data allowed us to identify the genes directly regulated by Zbtb11, and these were significantly enriched in genes with mitochondrial functions, with respiratory complex I and mitoribosome biogenesis being the overrepresented pathways. Subsequent biochemical experiments confirmed Zbtb11 is required for respiratory complex I assembly and for mitochondrial translation. In agreement with these findings Zbtb11 KO led to impaired respiration, proliferation arrest and cell death.
Project description:Zbtb11 is a transcription factor conserved in vertebrates. Mutations in its human gene cause a form of inherited intellectual disablity, while in zebrafish Zbtb11 mutations lead to impaired hematopoesis and neruonal development. To determine the genes regulated by Zbtb11 we generated an inducible KO ES cell line (Zbtb11 lox/lox, Rosa26 ERt2-Cre) that allows the rapid depletion of Zbtb11 upon treatment with 4-hydroxytamoxyfen (4OHT). We subsequently performed RNA-seq in Zbtb11 KO and control cells to determine differentially expressed genes. Upon Zbtb11 deletion 310 genes changed expression. Integration of the RNA-seq data with Zbtb11 ChIP-seq data (GEO series GSE125047) allowed us to distinguish between genes directly regulated by Zbtb11 and indirect changes. 204 differentially expressed genes were bound by Zbtb11, while 106 did not have Zbtb11 binding sites. Directly regulated genes were significantly enriched in genes with mitochondrial functions, while indirectly controlled genes were enriched for p53 targets. In agreement with these findings Zbtb11 KO led to impaired respiration, proliferation arrest and cell death.
Project description:To determined ZBTB11 and SET regulates genes in NCI-H1299, we esteblished NCI-H1299 cell lines in which ZBTB11 and SET has been knocked down by si-RNA. We then conducted differential expressed genes analysis using data generated form RNA-seq of H1299 cell lines at the condition of two genes knocked down.
Project description:From a forward genetic screen in zebrafish, we identified the transcription factor, ZBTB11, as critical for basal and emergency granulopoiesis and showed that ZBTB11 sits in a pathway directly downstream of master myeloid regulators including PU.1, GFI1 and CEBPa. To better understand target genes regulated by Zbtb11, RNAseq profiling was performed in neutrophils from WT and Zbtb11 mutant zebrafish.
Project description:Over 95% of pancreatic ductal adenocarcinomas (PDAC) harbor oncogenic mutations in K-Ras. Upon treatment with K-Ras inhibitors, PDAC cancer cells undergo metabolic reprogramming towards an oxidative phosphorylation-dependent, drug-resistant state. However, direct inhibition of complex I is poorly tolerated in patients due to on-target induction of peripheral neuropathy. In this work, we develop molecular glue degraders against ZBTB11, a C2H2 zinc finger transcription factor that regulates the nuclear transcription of components of the mitoribosome and electron transport chain. Our ZBTB11 degraders leverage the differences in demand for biogenesis of mitochondrial components between human neurons and rapidly-dividing pancreatic cancer cells, to selectively target the K-Ras inhibitor resistant state in PDAC. Combination treatment of both K28 Ras inhibitor-resistant cell lines and multidrug resistant patient-derived organoids resulted in superior anti-cancer activity compared to single agent treatment, while sparing hiPSC-derived neurons. Proteomic and stable isotope tracing studies revealed mitoribosome depletion and impairment of the TCA cycle as key events that mediate this response. Together, this work validates ZBTB11 as a vulnerability in K-Ras inhibitor-resistant PDAC and provides a suite of molecular glue degrader tool compounds to investigate its function.
Project description:Over 95% of pancreatic ductal adenocarcinomas (PDAC) harbor oncogenic mutations in K-Ras. However, upon treatment with K-Ras inhibitors, PDAC cancer cells undergo rapid metabolic reprogramming towards an oxidative phosphorylation-dependent, drug-resistant state. In this work, we demonstrate that this metabolic shift is associated with upregulation of the transcription factor ZBTB11, and both the metabolic state and the K-Ras inhibitor drug resistance can be attenuated by ZBTB11 depletion. We develop molecular glue degraders of ZBTB11 and demonstrate that they reprogram the aberrant transcriptome, proteome, metabolome, and bioenergetics of K-Ras inhibitor resistant PDAC, resensitizing them to K-Ras inhibition. ZBTB11 degradation leverages cell-type and cell-state specific differences in gene regulatory mechanisms controlling OXPHOS-pathway transcripts to selectively target the K-Ras inhibitor resistant state in PDAC while sparing hiPSC-derived neurons. Together, this work establishes ZBTB11 as a druggable vulnerability in K-Ras inhibitor-resistant PDAC and provides a suite of molecular glue degrader tool compounds to investigate its function.
Project description:Over 95% of pancreatic ductal adenocarcinomas (PDAC) harbor oncogenic mutations in K-Ras. However, upon treatment with K-Ras inhibitors, PDAC cancer cells undergo rapid metabolic reprogramming towards an oxidative phosphorylation-dependent, drug-resistant state. In this work, we demonstrate that this metabolic shift is associated with upregulation of the transcription factor ZBTB11, and both the metabolic state and the K-Ras inhibitor drug resistance can be attenuated by ZBTB11 depletion. We develop molecular glue degraders of ZBTB11 and demonstrate that they reprogram the aberrant transcriptome, proteome, metabolome, and bioenergetics of K-Ras inhibitor resistant PDAC, resensitizing them to K-Ras inhibition. ZBTB11 degradation leverages cell-type and cell-state specific differences in gene regulatory mechanisms controlling OXPHOS-pathway transcripts to selectively target the K-Ras inhibitor resistant state in PDAC while sparing hiPSC-derived neurons. Together, this work establishes ZBTB11 as a druggable vulnerability in K-Ras inhibitor-resistant PDAC and provides a suite of molecular glue degrader tool compounds to investigate its function.