Project description:Transforming growth factor (TGF)-beta induces apoptosis of many types of cancer cells and acts as a tumor suppressor. We found lower expression of TGF-beta type II receptor (TbRII) in most of SCLC cells and tissues than in normal lung epithelial cells and normal lung tissues, respectively. In vitro cell growth and in vivo tumor formation were suppressed by TGF-beta-mediated apoptosis when the wild-type TbRII was overexpressed in SCLC cells. We therefore determined Smad2 and Smad3 (Smad2/3) binding sites in a SCLC cell line H345 stably expressing exogenous TbRII (H345-TbRII) to identify target genes of TGF-beta. Smad2 and Smad3 binding sites in H345-TbRII cells were determined by ChIP-seq (one sample analysis, without replicates).
Project description:Study of Smad2 and Eomesa genomic binding in zebrafish blastulas, their relationship to eachother and the relaptionship between genomic binding and Ndr1 and Eomesa responsive genes as identified by microarray and RNA-seq. Replicate ChIP samples with associated input for Smad2 and Eomesa - 4x ChIP samples (2 per factor); 2x input samples
Project description:This experiment was designed to determine the interactome of SMAD2/3 in human pluripotent stem cells (hPSCs). hPSCs were cultured in standard pluripotency-promoting conditions, or induced to differentiate towards the definitive endoderm lineage for 36h. Endogenous SMAD2/3 was immunoprecipitated from nuclear extracts in these two conditions using a specific antibody. Non-immune IgG immunoprecipitations were performed as negative controls. Three biological replicates per conditions were analyzed by quantitative label-free mass spectrometry.
Project description:The transforming growth factor beta (TGFβ) related signaling is one of the most important signaling pathways regulating early developmental events. Smad2 and Smad3 are structurally similar and it is mostly considered that they are equally important in mediating TGFβ signals. Here, we show that Smad3 is an insensitive TGFβ transducer as compared with Smad2. Smad3 preferentially localizes within the nucleus and is thus sequestered from membrane signaling. The ability of Smad3 in oligomerization with Smad4 upon agonist stimulation is also impaired given its unique linker region. Smad2 mediated TGFβ signaling plays a crucial role in epiblast development and patterning of three germ layers. However, signaling unrelated nuclear localized Smad3 is dispensable for TGFβ signaling-mediated epiblast specification, but important for early neural development, an event blocked by TGFβ/Smad2 signaling. Both Smad2 and Smad3 bind to the conserved Smads binding element (SBE), but they show nonoverlapped target gene binding specificity. We conclude that Smad2 and Smad3 possess differential sensitivities in relaying TGFβ signaling and have distinct roles in regulating early developmental events. GFP, GFP-Smad2 and GFP-Smad3 constitutively expressed Smad3-/- mouse ESCs were differentiated to day6 neuroepithelia and collected for Chip-Seq with an anti-GFP antibody.
Project description:During development, key processes are orchestrated by Nodal/Activin signaling via SMAD2. Interplay between the SMADs, co-factors and chromatin determines cell-type specific responses, but the sequence of events underpinning SMAD2-mediated transcription is unknown. We performed RNA-and ChIP-sequencing for SMAD2, RNA Polymerase II and various histone modifications in different signaling states. Integration of these data reveals a dynamic transcriptional network downstream of Nodal/Activin signaling regulated by SMAD2 acting via multiple mechanisms. Upon ligand stimulation, SMAD2 can bind to pre-acetylated nucleosome-depleted sites, but also to unacetylated closed chromatin, where it induces nucleosome displacement and histone acetylation. Importantly, SMAD2 binding is highly dynamic and does not directly correlate with the transcriptional kinetics of target genes. Moreover, we show that SMAD2 initiates transcription by inducing RNA Polymerase II recruitment. We therefore define new paradigms for SMAD2-dependent transcription and provide a framework to understand how cells correctly execute gene expression programs in response to Nodal/Activin signaling.
Project description:Inhibitors for cyclin-dependent kinase (CDK) 4 and CDK6 have been established as effective therapeutic options for hormone receptor (HR)-positive, HER2-negative advanced breast cancer. Although the CDK4/6 inhibitors mainly target the cyclin D-CDK4/6-retinoblastoma tumor suppressor protein (RB) axis, little is known about clinical impact of inhibiting phosphorylation of other CDK4/6 target proteins. Here, we have focused on other CDK4/6 targets, SMAD proteins. We showed that a CDK4/6 inhibitor Palbociclib and Activin-SMAD2 signaling cooperatively inhibited cell cycle progression of a luminal-type breast cancer cell line T47D. Mechanistically, Palbociclib enhanced SMAD2 binding to the genome through inhibiting linker phosphorylation of the SMAD2 protein by CDK4/6. Comparison of the SMAD2 ChIP-seq data of T47D with those of a triple-negative breast cancer cell line Hs578T indicated that Palbociclib augments different SMAD2-mediated program defined based on types of cells, and enhances SMAD2 binding to the target regions on the genome without affecting its binding pattern. Collectively, the CDK4/6 inhibitor facilitates the cytostatic effects of Activin-SMAD2, while it also enhances its tumor promoting effects depending on types of breast cancer.
Project description:Smad2 and Smad3 (Smad2/3) primarily mediates the transforming growth factor-β (TGF-β) signaling that drives cell proliferation, differentiation, and migration. The dynamics of the Smad2/3 phosphorylation provides the key mechanism for regulating the TGF-β signaling pathway. Here we identified NLK as a novel regulator of TGF-β signaling pathway via modulating the phosphorylation of Smad2/3 in the linker region.
Project description:Inhibitors for cyclin-dependent kinase (CDK) 4 and CDK6 have been established as effective therapeutic options for hormone receptor (HR)-positive, HER2-negative advanced breast cancer. Although the CDK4/6 inhibitors mainly target the cyclin D-CDK4/6-retinoblastoma tumor suppressor protein (RB) axis, little is known about clinical impact of inhibiting phosphorylation of other CDK4/6 target proteins. Here, we have focused on other CDK4/6 targets, SMAD proteins. We showed that a CDK4/6 inhibitor Palbociclib and Activin-SMAD2 signaling cooperatively inhibited cell cycle progression of a luminal-type breast cancer cell line T47D. Mechanistically, Palbociclib enhanced SMAD2 binding to the genome through inhibiting linker phosphorylation of the SMAD2 protein by CDK4/6. Comparison of the SMAD2 ChIP-seq data of T47D with those of a triple-negative breast cancer cell line Hs578T indicated that Palbociclib augments different SMAD2-mediated program defined based on types of cells, and enhances SMAD2 binding to the target regions on the genome without affecting its binding pattern. Collectively, the CDK4/6 inhibitor facilitates the cytostatic effects of Activin-SMAD2, while it also enhances its tumor promoting effects depending on types of breast cancer.
Project description:Uterine double conditional inactivation of Smad2 and Smad3 in mice results in endometrial dysregulation, infertility, and uterine cancer. Smad2/3 cKO mice demonstrate abnormal expression of genes involved in inflammation, cell-cycle checkpoint, migration, steroid biosynthesis, and SMAD1/5-driven genes. We performed RNA-sequencing to identify the gene expression differences between the uterine epithelium of control and Smad2/3 cKO. To control for estrous cycle variations, the uterine epithelium was collected from mice at 0.5 dpc. Global gene expression profiles of Smad2/3 cKO versus control mice was analyzed. Our RNA sequencing analysis was performed at 6 weeks of life and already showed significant differences in migratory (Agr2,Slit2) and inflammatory (Ccl20, Crispld2) markers between Smad2/3 cKO and control mice.
Project description:Purpose: We aimed to identify miRNAs which are induced by the Activin/Nodal effectors, P-Smad2/3, in order to further our understanding of how P-Smad2/3 controls downstream gene expression in mouse ES cells to regulate crucial biological processes. Methods: We used a previously developed Tetracycline-On (Tet-On) system (TAG1) to manipulate the levels of P-Smad2/3 in mouse ES cells and performed an Illumina deep-sequencing screen to identify miRNAs which followed the P-Smad2/3 pathway. Results: We filtered the deep-seq data to identify a list of 28 miRNAs which showed a >1.25 fold increase in response to P-Smad2/3 induction and a >1.25 fold decrease in response to P-Smad2/3 repression. Conclusions: Our study represents a comprehensive global profiling of miRNA expression in response to changes in P-Smad2/3 levels in mouse ES cells.