| 1. |
- Arase, Mayu, et al.
(författare)
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Transforming growth factor-beta-induced lncRNA-Smad7 inhibits apoptosis of mouse breast cancer JygMC(A) cells
- 2014
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Ingår i: Cancer Science. - : Wiley. - 1347-9032 .- 1349-7006. ; 105:8, s. 974-982
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Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor (TGF)-beta exhibits both pro-apoptotic and anti-apoptotic effects on epithelial cells in a context-dependent manner. The anti-apoptotic function of TGF-beta is mediated by several downstream regulatory mechanisms, and has been implicated in the tumor-progressive phenotype of breast cancer cells. We conducted RNA sequencing of mouse mammary gland epithelial (NMuMG) cells and identified a long non-coding RNA, termed lncRNA-Smad7, which has anti-apoptotic functions, as a target of TGF-beta lncRNA-Smad7 was located adjacent to the mouse Smad7 gene, and its expression was induced by TGF-beta in all of the mouse mammary gland epithelial cell lines and breast cancer cell lines that we evaluated. Suppression of lncRNA-Smad7 expression cancelled the anti-apoptotic function of TGF-beta In contrast, forced expression of lncRNA-Smad7 rescued apoptosis induced by a TGF-beta type I receptor kinase inhibitor in the mouse breast cancer cell line JygMC(A). The anti-apoptotic effect of lncRNA-Smad7 appeared to occur independently of the transcriptional regulation by TGF-beta of anti-apoptotic DEC1 and pro-apoptotic Bim proteins. Small interfering RNA for lncRNA-Smad7 did not alter the process of TGF-beta-induced epithelial-mesenchymal transition, phosphorylation of Smad2 or expression of the Smad7 gene, suggesting that the contribution of this lncRNA to TGF-beta functions may be restricted to apoptosis. Our findings suggest a complex mechanism for regulating the anti-apoptotic and tumor-progressive aspects of TGF-beta signaling.
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| 2. |
- Hudson, Thomas J., et al.
(författare)
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International network of cancer genome projects
- 2010
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 464:7291, s. 993-998
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Tidskriftsartikel (refereegranskat)abstract
- The International Cancer Genome Consortium (ICGC) was launched to coordinate large-scale cancer genome studies in tumours from 50 different cancer types and/or subtypes that are of clinical and societal importance across the globe. Systematic studies of more than 25,000 cancer genomes at the genomic, epigenomic and transcriptomic levels will reveal the repertoire of oncogenic mutations, uncover traces of the mutagenic influences, define clinically relevant subtypes for prognosis and therapeutic management, and enable the development of new cancer therapies.
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| 3. |
- Johansson, Erik, et al.
(författare)
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Exogenous introduction of tissue inhibitor of metalloproteinase 2 reduces accelerated growth of TGF-β-disrupted diffuse-type gastric carcinoma.
- 2010
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Ingår i: Cancer science. - : Wiley. - 1349-7006 .- 1347-9032. ; 101:11, s. 2398-403
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Tidskriftsartikel (refereegranskat)abstract
- Diffuse-type gastric carcinoma is characterized by rapid progression and poor prognosis. High expression of transforming growth factor (TGF)-β and thick stromal fibrosis are observed in this type of gastric carcinoma. We have previously shown that disruption of TGF-β signaling via introduction of a dominant negative form of the TGF-β type II receptor (dnTβRII) into diffuse-type gastric cancer cell lines, including OCUM-2MLN, caused accelerated tumor growth through induction of tumor angiogenesis in vivo. In the present study, we show that TGF-β induces upregulation of expression of tissue inhibitor of metalloproteinase 2 (TIMP2) in the OCUM-2MLN cell line in vitro, and that expression of TIMP2 is repressed by dnTβRII expression in vivo. Transplantation of the OCUM-2MLN cells to nude mice exhibited accelerated tumor growth in response to dnTβRII expression, which was completely abolished when TIMP2 was coexpressed with dnTβRII. Although the blood vessel density of TIMP2-expressing tumors was only slightly decreased, the degree of hypoxia in tumor tissues was significantly increased and pericytes covering tumor vasculature were decreased by TIMP2 expression in OCUM-2MLN cells, suggesting that the function of tumor vasculatures was repressed by TIMP2 and consequently tumor growth was reduced. These findings provide evidence that one of the mechanisms of the increase in angiogenesis in diffuse-type gastric carcinoma is the downregulation of the anti-angiogenic protein TIMP2.
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| 4. |
- Mizutani, Anna, et al.
(författare)
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Cell type-specific target selection by combinatorial binding of Smad2/3 proteins and hepatocyte nuclear factor 4alpha in HepG2 cells
- 2011
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 286:34, s. 29848-29860
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Tidskriftsartikel (refereegranskat)abstract
- Specific regulation of target genes by transforming growth factor-β (TGF-β) in a given cellular context is determined in part by transcription factors and cofactors that interact with the Smad complex. In this study, we determined Smad2 and Smad3 (Smad2/3) binding regions in the promoters of known genes in HepG2 hepatoblastoma cells, and we compared them with those in HaCaT epidermal keratinocytes to elucidate the mechanisms of cell type- and context-dependent regulation of transcription induced by TGF-β. Our results show that 81% of the Smad2/3 binding regions in HepG2 cells were not shared with those found in HaCaT cells. Hepatocyte nuclear factor 4α (HNF4α) is expressed in HepG2 cells but not in HaCaT cells, and the HNF4α-binding motif was identified as an enriched motif in the HepG2-specific Smad2/3 binding regions. Chromatin immunoprecipitation sequencing analysis of HNF4α binding regions under TGF-β stimulation revealed that 32.5% of the Smad2/3 binding regions overlapped HNF4α bindings. MIXL1 was identified as a new combinatorial target of HNF4α and Smad2/3, and both the HNF4α protein and its binding motif were required for the induction of MIXL1 by TGF-β in HepG2 cells. These findings generalize the importance of binding of HNF4α on Smad2/3 binding genomic regions for HepG2-specific regulation of transcription by TGF-β and suggest that certain transcription factors expressed in a cell type-specific manner play important roles in the transcription regulated by the TGF-β-Smad signaling pathway.
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| 5. |
- Morikawa, Masato, et al.
(författare)
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BMP Sustains Embryonic Stem Cell Self-Renewal through Distinct Functions of Different Kruppel-like Factors
- 2016
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Ingår i: Stem Cell Reports. - : Elsevier BV. - 2213-6711. ; 6:1, s. 64-73
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Tidskriftsartikel (refereegranskat)abstract
- Bone morphogenetic protein (BMP) signaling exerts paradoxical roles in pluripotent stem cells (PSCs); it sustains self-renewal of mouse embryonic stem cells (ESCs), while it induces differentiation in other PSCs, including human ESCs. Here, we revisit the roles of BMP-4 using mouse ESCs (mESCs) in naive and primed states. SMAD1 and SMAD5, which transduce BMP signals, recognize enhancer regions together with KLF4 and KLF5 in naive mESCs. KLF4 physically interacts with SMAD1 and suppresses its activity. Consistently, a subpopulation of cells with active BMP-SMAD can be ablated without disturbing the naive state of the culture. Moreover, Smad1/5 double-knockout mESCs stay in the naive state, indicating that the BMP-SMAD pathway is dispensable for it. In contrast, the MEK5-ERK5 pathway mediates BMP-4-induced self-renewal of mESCs by inducing Klf2, a critical factor for the ground state pluripotency. Our study illustrates that BMP exerts its self-renewing effect through distinct functions of different Kruppel-like factors.
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| 6. |
- Morikawa, Masato, et al.
(författare)
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ChIP-seq reveals cell type-specific binding patterns of BMP-specific Smads and a novel binding motif
- 2011
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Ingår i: Nucleic Acids Research. - : Oxford University Press. - 0305-1048 .- 1362-4962. ; 39:20, s. 8712-8727
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Tidskriftsartikel (refereegranskat)abstract
- Dysregulated bone morphogenetic protein (BMP) signaling in endothelial cells (ECs) and pulmonary arterial smooth muscle cells (PASMCs) are implicated in human genetic disorders. Here, we generated genome-wide maps of Smad1/5 binding sites in ECs and PASMCs. Smad1/5 preferentially bound to the region outside the promoter of known genes, and the binding was associated with target gene upregulation. Cell-selective Smad1/5 binding patterns appear to be determined mostly by cell-specific differences in baseline chromatin accessibility patterns. We identified, for the first time, a Smad1/5 binding motif in mammals, and termed GC-rich Smad binding element (GC-SBE). Several sequences in the identified GC-SBE motif had relatively weak affinity for Smad binding, and were enriched in cell type-specific Smad1/5 binding regions. We also found that both GC-SBE and the canonical SBE affect binding affinity for the Smad complex. Furthermore, we characterized EC-specific Smad1/5 target genes and found that several Notch signaling pathway-related genes were induced by BMP in ECs. Among them, a Notch ligand, JAG1 was regulated directly by Smad1/5, transactivating Notch signaling in the neighboring cells. These results provide insights into the molecular mechanism of BMP signaling and the pathogenesis of vascular lesions of certain genetic disorders, including hereditary hemorrhagic telangiectasia.
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| 7. |
- Morikawa, Masato, et al.
(författare)
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The ALK-1/SMAD/ATOH8 axis attenuates hypoxic responses and protects against the development of pulmonary arterial hypertension
- 2019
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Ingår i: Science Signaling. - : American Association for the Advancement of Science. - 1945-0877 .- 1937-9145. ; 12:607
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Tidskriftsartikel (refereegranskat)abstract
- Dysregulated bone morphogenetic protein (BMP) signaling in endothelial cells (ECs) is implicated in vascular diseases such as pulmonary arterial hypertension (PAH). Here, we showed that the transcription factor ATOH8 was a direct target of SMAD1/5 and was induced in a manner dependent on BMP but independent of Notch, another critical signaling pathway in ECs. In zebrafish and mice, inactivation of Atoh8 did not cause an arteriovenous malformation-like phenotype, which may arise because of dysregulated Notch signaling. In contrast, Atoh8-deficient mice exhibited a phenotype mimicking PAH, which included increased pulmonary arterial pressure and right ventricular hypertrophy. Moreover, ATOH8 expression was decreased in PAH patient lungs. We showed that in cells, ATOH8 interacted with hypoxia-inducible factor 2 alpha (HIF-2 alpha) and decreased its abundance, leading to reduced induction of HIF-2 alpha target genes in response to hypoxia. Together, these findings suggest that the BMP receptor type II/ALK-1/SMAD/ATOH8 axis may attenuate hypoxic responses in ECs in the pulmonary circulation and may help prevent the development of PAH.
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| 8. |
- Sundqvist, Anders, et al.
(författare)
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JUNB governs a feed-forward network of TGF beta signaling that aggravates breast cancer invasion
- 2018
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Ingår i: Nucleic Acids Research. - : OXFORD UNIV PRESS. - 0305-1048 .- 1362-4962. ; 46:3, s. 1180-1195
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Tidskriftsartikel (refereegranskat)abstract
- It is well established that transforming growth factor-beta (TGF beta) switches its function from being a tumor suppressor to a tumor promoter during the course of tumorigenesis, which involves both cell-intrinsic and environment-mediated mechanisms. We are interested in breast cancer cells, in which SMAD mutations are rare and interactions between SMAD and other transcription factors define pro-oncogenic events. Here, we have performed chromatin immunoprecipitation (ChIP)-sequencing analyses which indicate that the genome-wide landscape of SMAD2/3 binding is altered after prolonged TGF beta stimulation. De novo motif analyses of the SMAD2/3 binding regions predict enrichment of binding motifs for activator protein (AP) 1 in addition to SMAD motifs. TGF beta-induced expression of the AP1 component JUNB was required for expression of many late invasion-mediating genes, creating a feed-forward regulatory network. Moreover, we found that several components in the WNT pathway were enriched among the late TGF beta-target genes, including the invasion-inducing WNT7 proteins. Consistently, overexpression of WNT7A or WNT7B enhanced and potentiated TGF beta-induced breast cancer cell invasion, while inhibition of the WNT pathway reduced this process. Our study thereby helps to explain how accumulation of pro-oncogenic stimuli switches and stabilizes TGF beta-induced cellular phenotypes of epithelial cells.
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| 9. |
- van Thuijl, Hinke F., et al.
(författare)
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Evolution of DNA repair defects during malignant progression of low-grade gliomas after temozolomide treatment
- 2015
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Ingår i: Acta Neuropathologica. - : Springer Verlag (Germany). - 0001-6322 .- 1432-0533. ; 129:4, s. 597-607
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Tidskriftsartikel (refereegranskat)abstract
- Temozolomide (TMZ) increases the overall survival of patients with glioblastoma (GBM), but its role in the clinical management of diffuse low-grade gliomas (LGG) is still being defined. DNA hypermethylation of the O (6) -methylguanine-DNA methyltransferase (MGMT) promoter is associated with an improved response to TMZ treatment, while inactivation of the DNA mismatch repair (MMR) pathway is associated with therapeutic resistance and TMZ-induced mutagenesis. We previously demonstrated that TMZ treatment of LGG induces driver mutations in the RB and AKT-mTOR pathways, which may drive malignant progression to secondary GBM. To better understand the mechanisms underlying TMZ-induced mutagenesis and malignant progression, we explored the evolution of MGMT methylation and genetic alterations affecting MMR genes in a cohort of 34 treatment-na less than ve LGGs and their recurrences. Recurrences with TMZ-associated hypermutation had increased MGMT methylation compared to their untreated initial tumors and higher overall MGMT methylation compared to TMZ-treated non-hypermutated recurrences. A TMZ-associated mutation in one or more MMR genes was observed in five out of six TMZ-treated hypermutated recurrences. In two cases, pre-existing heterozygous deletions encompassing MGMT, or an MMR gene, were followed by TMZ-associated mutations in one of the genes of interest. These results suggest that tumor cells with methylated MGMT may undergo positive selection during TMZ treatment in the context of MMR deficiency.
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| 10. |
- Vasilaki, Eleftheria, et al.
(författare)
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Ras and TGF-beta signaling enhance cancer progression by promoting the Delta Np63 transcriptional program
- 2016
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Ingår i: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 9:442
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Tidskriftsartikel (refereegranskat)abstract
- The p53 family of transcription factors includes p63, which is a master regulator of gene expression in epithelial cells. Determining whether p63 is tumor-suppressive or tumorigenic is complicated by isoform-specific and cellular context-dependent protein associations, as well as antagonism from mutant p53. Delta Np63 is an amino-terminal-truncated isoform, that is, the predominant isoform expressed in cancer cells of epithelial origin. In HaCaT keratinocytes, which have mutant p53 and Delta Np63, we found that mutant p53 antagonized Delta Np63 transcriptional activity but that activation of Ras or transforming growth factor-beta (TGF-beta) signaling pathways reduced the abundance of mutant p53 and strengthened target gene binding and activity of Delta Np63. Among the products of Delta Np63-induced genes was dual-specificity phosphatase 6 (DUSP6), which promoted the degradation of mutant p53, likely by dephosphorylating p53. Knocking down all forms of p63 or DUSP6 and DUSP7 (DUSP6/7) inhibited the basal or TGF-beta-induced or epidermal growth factor (which activates Ras)-induced migration and invasion in cultures of p53-mutant breast cancer and squamous skin cancer cells. Alternatively, overexpressing Delta Np63 in the breast cancer cells increased their capacity to colonize various tissues upon intracardiac injection in mice, and this was inhibited by knocking down DUSP6/7 in these Delta Np63-overexpressing cells. High abundance of Delta Np63 in various tumors correlated with poor prognosis in patients, and this correlation was stronger in patients whose tumors also had a mutation in the gene encoding p53. Thus, oncogenic Ras and TGF-beta signaling stimulate cancer progression through activation of the Delta Np63 transcriptional program.
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