Project description:The prevalent understanding of Hippo signaling is one inhibitory pathway in tumor growth via deactivating the potential of YAP-TEAD transcriptional complex. The aberrant activation of YAP was observed in a series of human malignancies. However, recent studies implicate that in certain cancer types, YAP could be a tumor suppressor. Here, we reported a context-dependent function of YAP in clear cell renal carcinoma (ccRCC). Inhibition of Hippo kinase activity impeded ccRCC tumor growth and NF-κB transcriptional programs. Pharmacological blocking Hippo kinase activity or ectopic activation of YAP suppressed tumor growth in xenograft and PDX models. Mechanism studies revealed that TEAD could synchronize with P65 for NF-κB signaling activation, while YAP disrupted TEAD-NF-κB interactions and dissociated P65 from its target gene promoter, thereby inhibiting NF-κB transcriptional programs and ccRCC tumor growth. Our study identified a novel crosstalk between Hippo and NF-κB pathway, uncovered a non-canonical regulation of Hippo/YAP axis in renal cancer and suggested a novel strategy to ccRCC treatments by YAP activation.
Project description:The prevalent understanding of Hippo signaling is one inhibitory pathway in tumor growth via deactivating the potential of YAP-TEAD transcriptional complex. The aberrant activation of YAP was observed in a series of human malignancies. However, recent studies implicate that in certain cancer types, YAP could be a tumor suppressor. Here, we reported a context-dependent function of YAP in clear cell renal carcinoma (ccRCC). Inhibition of Hippo kinase activity impeded ccRCC tumor growth and NF-κB transcriptional programs. Pharmacological blocking Hippo kinase activity or ectopic activation of YAP suppressed tumor growth in xenograft and PDX models. Mechanism studies revealed that TEAD could synchronize with P65 for NF-κB signaling activation, while YAP disrupted TEAD-NF-κB interactions and dissociated P65 from its target gene promoter, thereby inhibiting NF-κB transcriptional programs and ccRCC tumor growth. Our study identified a novel crosstalk between Hippo and NF-κB pathway, uncovered a non-canonical regulation of Hippo/YAP axis in renal cancer and suggested a novel strategy to ccRCC treatments by YAP activation.
Project description:Splicing dysregulations extensively occur in cancers, yet the biological consequences of such alterations are mostly undefined. Here we report that the Hippo-YAP signaling, a key pathway that regulates cell proliferation and organ size, is under control of a new splicing switch. We show that TEAD4, the transcription factor that mediates Hippo-YAP signaling, undergoes alternative splicing facilitated by the tumor suppressor RBM4, producing a truncated isoform, TEAD4-S, which lacks N-terminal DNA-binding domain but maintains YAP-interaction domain. TEAD4-S is located in both nucleus and cytoplasm, acting as a dominant negative isoform to YAP activity. Consistently, TEAD4-S is reduced in cancer cells, and its re-expression suppresses cancer cell proliferation and migration, inhibiting tumor growth in xenograft mouse model. Furthermore, TEAD4-S is reduced in human cancers, and patients with elevated TEAD4-S levels have improved survival. Altogether these data reveal a novel RBM4-mediated splicing switch that serves to fine-tune Hippo-YAP pathway. Cell lines stably expressing YAP, YAP/TEAD4-S, YAP/TEAD4-FL, YAP/RBM4 and control vector were created, and the total RNA was purified from the cells using TRIzol reagents. The polyadenylated RNAs were purified for construction of sequencing library using kapa TruSeq Total RNA Sample Prep kits (UNC High Throughput Sequencing Facility).
Project description:Splicing dysregulations extensively occur in cancers, yet the biological consequences of such alterations are mostly undefined. Here we report that the Hippo-YAP signaling, a key pathway that regulates cell proliferation and organ size, is under control of a new splicing switch. We show that TEAD4, the transcription factor that mediates Hippo-YAP signaling, undergoes alternative splicing facilitated by the tumor suppressor RBM4, producing a truncated isoform, TEAD4-S, which lacks N-terminal DNA-binding domain but maintains YAP-interaction domain. TEAD4-S is located in both nucleus and cytoplasm, acting as a dominant negative isoform to YAP activity. Consistently, TEAD4-S is reduced in cancer cells, and its re-expression suppresses cancer cell proliferation and migration, inhibiting tumor growth in xenograft mouse model. Furthermore, TEAD4-S is reduced in human cancers, and patients with elevated TEAD4-S levels have improved survival. Altogether these data reveal a novel RBM4-mediated splicing switch that serves to fine-tune Hippo-YAP pathway.
Project description:NF-κB has an essential role in innate immune response and inflammation and is involved in cancer development and progression. We apply the SEC-PCP-SILAC method incorporating metabolic labeling, size exclusion chromatography and protein correlation profiling to construct a complex network of interactome rearrangement in response to NF-κB modulation in breast cancer cells. Our interaction network represents a complex insight into the dynamics of MCF-7 protein interactome associated with NF-κB pathway. Our dataset could serve as a basis for future studies characterizing role of NF-κB in breast cancer cellular pathways. This PRIDE project includes results from SILAC labeled and label-free replicates from the SEC-PCP-SILAC analysis of protein complexes in MCF-7 cells with inhibited and uninhibited NF-κB pathway, results from the immunoprecipitation experiment aimed at interaction partners of NF-κB factor RELA, analysis of total proteome after NF-κB inhibition, and results from SEC fractionation of untreated and unlabeled MCF-7 cells.
Project description:The transcription factor NF-κB is the master regulator of the immune response but also regulates gene expression to influences cell survival, proliferation and differentiation. Inducible site-specific phosphorylation of NF-κB is critical for its activity and appears to be important in gene specific transcriptional control. Promyelocytic Leukemia (PML) is a nuclear protein that forms sub-nuclear structures termed nuclear bodies associated with transcriptionally active genomic regions. We demonstrate that PML promotes NF-κB- induced transcriptional responses by promoting the phosphorylation of NF-κB p65 at key regulatory sites. Our findings demonstrate a critical role for PML in promoting NF-κB transcriptional activity through signal induced post-translational modifications.
Project description:Transcriptional profiling of human control and Néstor-Guillermo Progeria Syndrome (NGPS) fibroblasts and induced pluripotent stem cells (iPSCs). Somatic cell reprogramming involves rejuvenation of adult cells and relies on the ability to erase age-associated molecular marks. Accordingly, reprogramming efficiency declines with ageing, and age-associated features such as genetic instability, cell senescence or telomere shortening negatively affect this process. However, the regulatory mechanisms that constitute age-associated barriers for cell reprogramming remain largely unknown. Here, by using cells from patients with premature ageing, we demonstrate that NF-κB activation is a critical barrier for the generation of induced pluripotent stem cells (iPSCs) in ageing. We show that NF-κB repression occurs during cell reprogramming towards a pluripotent state. Conversely, ageing-associated NF-κB hyperactivation impairs generation of iPSCs by eliciting reprogramming repressors DOT1L and YY1, reinforcing cell senescence signals and down-regulating pluripotency genes. We also show that genetic and pharmacological NF-κB inhibitory strategies significantly increase the reprogramming efficiency of fibroblasts from Néstor-Guillermo Progeria Syndrome (NGPS) and Hutchinson-Gilford Progeria Syndrome (HGPS) patients, as well as from normal aged donors. Finally, we demonstrate that DOT1L inhibition in vivo ameliorates the accelerated ageing phenotype and extends lifespan in a progeroid animal model. Collectively, our results provide evidence for a novel role of NF-κB in the control of cell fate transitions and reinforce the interest of studying age-associated molecular impairments to implement cell reprogramming methodologies, and to identify new targets of rejuvenation strategies. Control and NGPS fibroblasts were reprogrammed. RNA was extracted and transcriptional profiling was obtained with GeneChip Human Exon 1.0 ST Arrays.
Project description:Transcriptional profiling of human control and Néstor-Guillermo Progeria Syndrome (NGPS) mesenchymal stem cells (MSCs). Somatic cell reprogramming involves rejuvenation of adult cells and relies on the ability to erase age-associated molecular marks. Accordingly, reprogramming efficiency declines with ageing, and age-associated features such as genetic instability, cell senescence or telomere shortening negatively affect this process. However, the regulatory mechanisms that constitute age-associated barriers for cell reprogramming remain largely unknown. Here, by using cells from patients with premature ageing, we demonstrate that NF-κB activation is a critical barrier for the generation of induced pluripotent stem cells (iPSCs) in ageing. We show that NF-κB repression occurs during cell reprogramming towards a pluripotent state. Conversely, ageing-associated NF-κB hyperactivation impairs generation of iPSCs by eliciting reprogramming repressors DOT1L and YY1, reinforcing cell senescence signals and down-regulating pluripotency genes. We also show that genetic and pharmacological NF-κB inhibitory strategies significantly increase the reprogramming efficiency of fibroblasts from Néstor-Guillermo Progeria Syndrome (NGPS) and Hutchinson-Gilford Progeria Syndrome (HGPS) patients, as well as from normal aged donors. Finally, we demonstrate that DOT1L inhibition in vivo ameliorates the accelerated ageing phenotype and extends lifespan in a progeroid animal model. Collectively, our results provide evidence for a novel role of NF-κB in the control of cell fate transitions and reinforce the interest of studying age-associated molecular impairments to implement cell reprogramming methodologies, and to identify new targets of rejuvenation strategies. Control and NGPS MSCs were differentiated into bone in the presence or absence of sodium salicylate. Total RNA was extracted and global gene expression was analyzed.
Project description:MTD project_description Inflammation and decreased stem cell function characterize organism aging, yet the relationship between these factors remains incompletely understood. This study shows that aged hematopoietic stem and progenitor cells exhibit increased ground-stage NF-κB activity, which enhances their responsiveness to undergo differentiation and loss of self-renewal in response to inflammation. The study identifies Rad21/cohesin as a critical mediator of NF-κB signals, by increasing chromatin accessibility of inter-/intra-genic and enhancer regions. Rad21/NF-κB are required for normal differentiation, but limit self-renewal of hematopoietic stem cells (HSCs) during aging and inflammation in an NF-κB dependent manner. HSCs from aged mice fail to downregulate Rad21/cohesin and inflammation/differentiation inducing signals in the resolution phase after acute inflammation. and The inhibition of cohesin/NF-κB is sufficient to revert the hypersensitivity of aged HSPCs to inflammation-induced differentiation. During aging, myeloid-biased HSCs with disrupted and naturally occurring reduced expression of Rad21/cohesin are increasingly selected over lymphoid-biased HSCs. Together, Rad21/cohesin mediated NF-κB signaling limits HSPC function during aging and selects for cohesin deficient HSCs with myeloid skewed differentiation.