Project description:miRNA-1343 is an uncharacterized miRNA predicted to target a number of genes involved in epithelial cell function including TGF-beta signaling, cell adhesion, and cell proliferation. We transiently overexpressed miRNA-1343 or a non-targeting control miRNA in A549 and 16HBE14o- human airway cell lines. As predicted, RNA-seq following miRNA-1343 overexpression showed significant downregulation of genes involved in these pathways. Furthermore, genes involved in cholesterol and lipid biosynthesis were found to be significantly upregulated by miRNA-1343 overexpression.
Project description:We previously identified miR-1343 as a potent repressor of TGF-b signaling and fibrosis through the direct attenuation of both canonical TGF-b receptors. Here, we build upon our previous findings to better characterize the function of endogenous miR-1343 in normal biology. CRISPR/Cas9 techniques were used to delete the miR-1343 locus in A549 lung epithelial cells. Loss of miR-1343 was found to impact several processes and genes implicated in fibrosis and known to be TGF-b pathway effectors. These responses are opposite to those we observed previously when miR-1343 was overexpressed in the same cell type.
Project description:Transforming growth factor-β (TGF-β) signaling and microRNAs (miRNAs) are important gene regulatory components in cancer. Usually in advanced malignant stages, TGF-β signaling is elevated, but global miRNA expression is suppressed. Such a gene expression signature is well illustrated in a fibrosis/mesenchymal subtype of ovarian cancer (OC) that is of poor prognosis. However, the interplay between the two pathways in the OC subtype has not yet been elucidated. nc886 is a recently identified non-coding RNA implicated in several malignancies. nc886's high expression is associated with the poor prognosis of 285 patients in an OC cohort. Herein we have found in OC that nc886 expression is induced by TGF-β and that nc886 binds to the enzyme Dicer to inhibit the processing of miRNA precursors into mature forms. By preventing the miRNA pathway, nc886 emulates TGF-β in gene expression patterns and potentiates cell adhesion, migration, invasion, and drug resistance. We report nc886 as a novel molecular link between the TGF-β and miRNA pathways.
Project description:The epidermal growth factor receptor (EGFR) is overexpressed in approximately 90% of head and neck squamous cell carcinomas (HNSCC), and molecularly targeted therapy against the EGFR with the monoclonal antibody cetuximab modestly increases overall survival in head and neck cancer patients. We hypothesize that co-signaling through additional pathways limits the efficacy of cetuximab and EGFR-specific tyrosine kinase inhibitors (TKIs) in the clinical treatment of HNSCC. Analysis of gene expression changes in HNSCC cell lines treated 4 days with TKIs targeting EGFR and/or fibroblast growth factor receptors (FGFRs) identified transforming growth factor beta 2 (TGF-β2) induction in the three cell lines tested. Measurement of TGF-β2 mRNA validated this observation and extended it to additional cell lines. Moreover, TGF-β2 mRNA was increased in primary patient HNSCC xenografts treated for 4 weeks with cetuximab, demonstrating in vivo relevance of these findings. Functional genomics analyses with shRNA libraries identified TGF-β2 and TGF-β receptors (TGFβRs) as synthetic lethal genes in the context of TKI treatment. Further, direct RNAi-mediated silencing of TGF-β2 inhibited cell growth, both alone and in combination with TKIs. Also, a pharmacological TGFβRI inhibitor similarly inhibited basal growth and enhanced TKI efficacy. In summary, the studies support a TGF-β2-TGFβR pathway as a TKI-inducible growth pathway in HNSCC that limits efficacy of EGFR-specific inhibitors. HNSCC cell lines treated 4 days with TKIs targeting EGFR and/or fibroblast growth factor receptors (FGFRs) identified transforming growth factor beta 2 (TGF-β2) induction in the three cell lines tested
Project description:Pedro Vizán, Daniel S. J. Miller, Ilaria Gori, Debipriya Das, Bernhard Schmierer & Caroline S. Hill. Controlling long-term signaling: receptor dynamics determine attenuation and refractory behavior of the TGF-β pathway. Science Signaling 6, 305 (2013).
Understanding the complex dynamics of growth factor signaling requires both mechanistic and kinetic information. Although signaling dynamics have been studied for pathways downstream of receptor tyrosine kinases and G protein (heterotrimeric guanine nucleotide-binding protein)-coupled receptors, they have not been investigated for the transforming growth factor-β (TGF-β) superfamily pathways. Using an integrative experimental and mathematical modeling approach, we dissected the dynamic behavior of the TGF-β to Smad pathway, which is mediated by type I and type II receptor serine/threonine kinases, in response to acute, chronic, and repeated ligand stimulations. TGF-β exposure produced a transient response that attenuated over time, resulting in desensitized cells that were refractory to further acute stimulation. This loss of signaling competence depended on ligand binding, but not on receptor activity, and was restored only after the ligand had been depleted. Furthermore, TGF-β binding triggered the rapid depletion of signaling-competent receptors from the cell surface, with the type I and type II receptors exhibiting different degradation and trafficking kinetics. A computational model of TGF-β signal transduction from the membrane to the nucleus that incorporates our experimental findings predicts that autocrine signaling, such as that associated with tumorigenesis, severely compromises the TGF-β response, which we confirmed experimentally. Thus, we have shown that the long-term signaling behavior of the TGF-β pathway is determined by receptor dynamics, does not require TGF-β-induced gene expression, and influences context-dependent responses in vivo.
Project description:Myoblasts are supposed to participate in skeletal muscle fibrosis. In this dataset, myoblasts were treated with TGF-β and then miRNA sequencing was performed to identify potential targets.
Project description:Tumor immunogenicity enhanced by radiotherapy (RT), is often counterbalanced by immune evasive mechanisms and tissue remodeling effects via upregulation of transforming growth factor-β (TGF-β) and programmed cell death-ligand 1 (PD-L1). We report that bintrafusp alfa (BA), a bifunctional fusion protein that simultaneously inhibits TGF-β and PD-L1, is a favorable combination partner for RT in eradicating multiple treatment-resistant tumor models. Beneficial effects of BA+RT (BART) are partly attributed to counterbalancing undesired RT effects and local tumor microenvironment reprograming, leading to reconstitution of tumor immunity and regression of spontaneous lung metastases. Intriguingly, BA, but neither TGF-β trap nor anti–PD-L1 alone, attenuates late-stage RT-induced lung fibrosis. Single cell transcriptome show TGF-β expression is confined to PD-L1+ endothelium and M2/lipofibroblast-like cells. Hence, superior effects of BA could be attributed to its ability to trap TGF-β to relevant PD-L1+ compartments. Here, we provide rationales that BART resensitizes tumors and broadens the therapeutic window.
Project description:TGF-beta signaling in neural crest cells is required for normal craniofacial development. This signaling can be transduced via TGF-beta type I receptors (TGFbRI) using Smad-dependent or Smad independent signaling pathways. We used microarrays to identify TGF-beta-responsive genes that are dependent either on TGFbRI kinase, Tak1 kinase or both. Primary palatal mesenchymal cell cultures were established. Cultured cells were stimulated with TGF-beta2 in the presence or absence of TGFbRI kinase and Tak1 kinase inhibitors. Unstimulated cells were used as controls. Total RNAs were isolated and hybridized on Affymetrix microarrays.
Project description:TGF-beta signaling in neural crest cells is required for normal craniofacial development. This signaling can be transduced via TGF-beta type I receptors (TGFbRI) using Smad-dependent or Smad independent signaling pathways. We used microarrays to identify TGF-beta-responsive genes that are dependent either on TGFbRI kinase, Tak1 kinase or both.
Project description:Fibrosis is a core pathway that drives the progression of multiple chronic diseases for which there is a paucity of safe and effective treatments. In these diseases, transforming growth factor–β (TGF-β)–driven scarring propels disease progression. However, targeting this ubiquitously expressed cytokine is unlikely to yield a viable and safe antifibrotic therapy; thus, identification of alternative mechanisms to inhibit TGF-β signalling is required. We identified Mer tyrosine kinase (MERTK) as a TGF-β–inducible nodal effector of fibrosis that is up-regulated with fibrosis in multiple organs in both mice and humans. MERTK also induces TGF-β expression and promotes it’s signalling resulting in a positive feedback loop that promotes fibrosis. Mechanistically, MERTK regulates both canonical and non-canonical TGFβ signalling. Further downstream, MERTK modulates the fibrotic regulatory gene transcription network by regulating chromatin accessibility, RNA polymerase II (pol II) pausing and reprograming the enhancer landscape. Using mouse models of kidney, lung, and liver fibrosis, we demonstrate that this fibrosis-promoting signalling loop can be interrupted by loss of MERTK expression, leading to marked attenuation of fibrosis. Pharmacologic MERTK inhibition reduced fibrosis either when initiated immediately after injury or when initiated after fibrosis is established. Together, this data suggests that MERTK plays a critical role in modulating organ fibrosis, while small-molecule MERTK inhibitors are an attractive target for the treatment of diseases characterized by fibrosis.