| 1. |
- Dadras, Mahsa Shahidi, et al.
(författare)
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The polarity protein Par3 coordinates positively self-renewal and negatively invasiveness in glioblastoma
- 2021
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Ingår i: Cell Death and Disease. - : Springer Nature. - 2041-4889. ; 12:10
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Tidskriftsartikel (refereegranskat)abstract
- Glioblastoma (GBM) is a brain malignancy characterized by invasiveness to the surrounding brain tissue and by stem-like cells, which propagate the tumor and may also regulate invasiveness. During brain development, polarity proteins, such as Par3, regulate asymmetric cell division of neuro-glial progenitors and neurite motility. We, therefore, studied the role of the Par3 protein (encoded by PARD3) in GBM. GBM patient transcriptomic data and patient-derived culture analysis indicated diverse levels of expression of PARD3 across and independent from subtypes. Multiplex immunolocalization in GBM tumors identified Par3 protein enrichment in SOX2-, CD133-, and NESTIN-positive (stem-like) cells. Analysis of GBM cultures of the three subtypes (proneural, classical, mesenchymal), revealed decreased gliomasphere forming capacity and enhanced invasiveness upon silencing Par3. GBM cultures with suppressed Par3 showed low expression of stemness (SOX2 and NESTIN) but higher expression of differentiation (GFAP) genes. Moreover, Par3 silencing reduced the expression of a set of genes encoding mitochondrial enzymes that generate ATP. Accordingly, silencing Par3 reduced ATP production and concomitantly increased reactive oxygen species. The latter was required for the enhanced migration observed upon silencing of Par3 as anti-oxidants blocked the enhanced migration. These findings support the notion that Par3 exerts homeostatic redox control, which could limit the tumor cell-derived pool of oxygen radicals, and thereby the tumorigenicity of GBM.
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| 2. |
- Heldin, Paraskevi, et al.
(författare)
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Involvement of hyaluronan and CD44 in cancer and viral infections
- 2020
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Ingår i: Cellular Signalling. - : ELSEVIER SCIENCE INC. - 0898-6568 .- 1873-3913. ; 65
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Tidskriftsartikel (refereegranskat)abstract
- Hyaluronan and its major receptor CD44 are ubiquitously distributed. They have important structural as well as signaling roles, regulating tissue homeostasis, and their expression levels are tightly regulated. In addition to signaling initiated by the interaction of the intracellular domain of CD44 with cytoplasmic signaling molecules, CD44 has important roles as a co-receptor for different types of receptors of growth factors and cytokines. Dysregulation of hyaluronan-CD44 interactions is seen in diseases, such as inflammation and cancer. In the present communication, we discuss the mechanism of hyaluronan-induced signaling via CD44, as well as the involvement of hyaluronan-engaged CD44 in malignancies and in viral infections.
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| 3. |
- Karalis, Theodoros, et al.
(författare)
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Identification of a Small Molecule Inhibitor of Hyaluronan Synthesis, DDIT, Targeting Breast Cancer Cells
- 2022
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 14:23
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary The most aggressive subtype of breast cancer, triple-negative breast cancer, is characterized by an excessive accumulation of hyaluronan in the cancer and its peritumoral stroma, which has been linked to poor prognosis of the patients. Inhibitors of hyaluronan synthesis would thus have a potential clinical value. We have identified the thymidine analog 5 '-Deoxy-5 '-(1,3-Diphenyl-2-Imidazolidinyl)-Thymidine (DDIT) as a new non-toxic inhibitor of hyaluronan synthesis. DDIT is more potent than the available inhibitor 4-Methylumbelliferone (4-MU), and significantly suppressed the aggressiveness of triple-negative breast cancer cells grown in tissue culture. Breast cancer is a common cancer in women. Breast cancer cells synthesize large amounts of hyaluronan to assist their proliferation, survival, migration and invasion. Accumulation of hyaluronan and overexpression of its receptor CD44 and hyaluronidase TMEM2 in breast tumors correlate with tumor progression and reduced overall survival of patients. Currently, the only known small molecule inhibitor of hyaluronan synthesis is 4-methyl-umbelliferone (4-MU). Due to the importance of hyaluronan for breast cancer progression, our aim was to identify new, potent and chemically distinct inhibitors of its synthesis. Here, we report a new small molecule inhibitor of hyaluronan synthesis, the thymidine analog 5 '-Deoxy-5 '-(1,3-Diphenyl-2-Imidazolidinyl)-Thymidine (DDIT). This compound is more potent than 4-MU and displays significant anti-tumorigenic properties. Specifically, DDIT inhibits breast cancer cell proliferation, migration, invasion and cancer stem cell self-renewal by suppressing HAS-synthesized hyaluronan. DDIT appears as a promising lead compound for the development of inhibitors of hyaluronan synthesis with potential usefulness in breast cancer treatment.
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| 4. |
- Kolliopoulos, Constantinos, et al.
(författare)
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CD44 Depletion in Glioblastoma Cells Suppresses Growth and Stemness and Induces Senescence
- 2022
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 14:15
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary The hyaluronan receptor CD44 has an important role in glioblastoma multiforme (GBM) progression, but the precise mechanisms have not been elucidated. We have analyzed U251MG glioma cells, expressing CD44 or not, and grown in stem cell-like enriched spheres. Our results revealed that CD44 is important for cell growth and stemness, and for the prevention of senescence. Analysis by RNA sequencing revealed that CD44 is important for the interaction with the hyaluronan-enriched microenvironment. In addition, CD44 depletion impairs certain gene signatures, such as those for platelet-derived growth factor (PDGF) isoforms and PDGF receptors, as well as signatures related to hypoxia, glycolysis, and anti-tumor immune responses. Glioblastoma multiforme (GBM) is a lethal brain tumor, characterized by enhanced proliferation and invasion, as well as increased vascularization and chemoresistance. The expression of the hyaluronan receptor CD44 has been shown to correlate with GBM progression and poor prognosis. Here, we sought to elucidate the molecular mechanisms by which CD44 promotes GBM progression by knocking out (KO) CD44, employing CRISPR/Cas9 gene editing in U251MG cells. CD44-depleted cells exhibited an impaired proliferation rate, as shown by the decreased cell numbers, decreased Ki67-positive cell nuclei, diminished phosphorylation of CREB, and increased levels of the cell cycle inhibitor p16 compared to control cells. Furthermore, the CD44 KO cells showed decreased stemness and increased senescence, which was manifested upon serum deprivation. In stem cell-like enriched spheres, RNA-sequencing analysis of U251MG cells revealed a CD44 dependence for gene signatures related to hypoxia, the glycolytic pathway, and G2 to M phase transition. Partially similar results were obtained when cells were treated with the gamma-secretase inhibitor DAPT, which inhibits CD44 cleavage and therefore inhibits the release of the intracellular domain (ICD) of CD44, suggesting that certain transcriptional responses are dependent on CD44-ICD. Interestingly, the expression of molecules involved in hyaluronan synthesis, degradation, and interacting matrix proteins, as well as of platelet-derived growth factor (PDGF) isoforms and PDGF receptors, were also deregulated in CD44 KO cells. These results were confirmed by the knockdown of CD44 in another GBM cell line, U2990. Notably, downregulation of hyaluronan synthase 2 (HAS2) impaired the hypoxia-related genes and decreased the CD44 protein levels, suggesting a CD44/hyaluronan feedback circuit contributing to GBM progression.
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| 5. |
- Kolliopoulos, Constantinos, et al.
(författare)
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Has2 natural antisense RNA and Hmga2 promote Has2 expression during TGFβ-induced EMT in breast cancer
- 2019
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Ingår i: Matrix Biology. - : Elsevier BV. - 0945-053X .- 1569-1802. ; 80, s. 29-45
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Tidskriftsartikel (refereegranskat)abstract
- The glycosaminoglycan hyaluronan has a crucial role in tissue organization and cell signaling. Hyaluronan accumulates in conjunction with rapid tissue remodeling during embryogenesis, as well as in inflammatory conditions and cancer. We report a negative correlation between the expression of genes encoding hyaluronan synthase HAS2, its natural antisense transcript HAS2-AS, the chromatin modulating factor HMGA2 and transforming growth factor-β (TGFβ), and survival of patients with invasive breast carcinomas. In mouse mammary epithelial cells, TGFβ activates Smad and non-Smad signaling pathways, resulting in the transcriptional induction of Has2, Has2as (the mouse ortholog of HAS2-AS) and Hmga2, as well as epithelial-mesenchymal transition (EMT)-promoting transcription factors, such as Snail. Importantly, Has2as abrogation suppressed the TGFβ induction of EMT markers, including Snai1, Hmga2, Fn1, and suppressed the mesenchymal phenotype. TGFβ induction of Hmga2, Has2as and Has2, and synthesis of hyaluronan were accompanied with activation of Akt and Erk1/2 MAP-kinase signaling and were required for breast cancer cell motility. Importantly, the hyaluronan receptor Cd44, but not Hmmr, was required for TGFβ-mediated EMT phenotype. Interestingly, Has2as was found to contribute to the maintenance of stem cell factors and breast cancer stemness. Our findings show that Has2as has a key role in TGFβ- and HAS2-induced breast cancer EMT, migration and acquisition of stemness.
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| 6. |
- Kolliopoulos, Constantinos, et al.
(författare)
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TRAF4/6 Is Needed for CD44 Cleavage and Migration via RAC1 Activation
- 2021
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 13:5
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary Tumor cells receive signals from the surrounding extracellular matrix that affect their growth and survival. An important component of the extracellular matrix is the large polysaccharide hyaluronan, which binds and activates certain receptors at the cell surface, including CD44. Activation of CD44 initiates several signaling pathways; one of them involves the cleavage of CD44 by proteases, leading to the release of the intracellular domain of CD44, which after translocation to the nucleus affects the transcription of certain genes. In the present report, we elucidate the mechanism by which CD44 is cleaved, and show that this occurs at an increased rate in stem-like tumor cells grown in spheres. We also show that CD44 cleavage promotes the migration of tumor cells. Since the mechanism we have elucidated promotes tumorigenesis, it is possible that inhibition of this pathway may be beneficial in the treatment of tumor patients. The hyaluronan receptor CD44 can undergo proteolytic cleavage in two steps, leading to the release of its intracellular domain; this domain is translocated to the nucleus, where it affects the transcription of target genes. We report that CD44 cleavage in A549 lung cancer cells and other cells is promoted by transforming growth factor-beta (TGF beta) in a manner that is dependent on ubiquitin ligase tumor necrosis factor receptor-associated factor 4 or 6 (TRAF4 or TRAF6, respectively). Stem-like A549 cells grown in spheres displayed increased TRAF4-dependent expression of CD44 variant isoforms, CD44 cleavage, and hyaluronan synthesis. Mechanistically, TRAF4 activated the small GTPase RAC1. CD44-dependent migration of A549 cells was inhibited by siRNA-mediated knockdown of TRAF4, which was rescued by the transfection of a constitutively active RAC1 mutant. Our findings support the notion that TRAF4/6 mediates pro-tumorigenic effects of CD44, and suggests that inhibitors of CD44 signaling via TRAF4/6 and RAC1 may be beneficial in the treatment of tumor patients.
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| 7. |
- Kolliopoulos, Constantinos, et al.
(författare)
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Transforming growth factor β (TGFβ) induces NUAK kinase expression to fine-tune its signaling output
- 2019
-
Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 294:11, s. 4119-4136
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Tidskriftsartikel (refereegranskat)abstract
- TGFβ signaling via SMAD proteins and protein kinase pathways up- or down-regulates the expression of many genes and thus affects physiological processes, such as differentiation, migration, cell cycle arrest, and apoptosis during developmental or adult tissue homeostasis. We here report that NUAK family kinase 1 (NUAK1) and NUAK2 are two TGFβ target genes. NUAK1/2 belong to the AMP-activated protein kinase (AMPK) family, whose members control central and protein metabolism, polarity and overall cellular homeostasis. We found that TGFβ-mediated transcriptional induction of NUAK1 and NUAK2 requires SMAD family members 2, 3 and 4 (SMAD2/3/4) and mitogen activated protein kinase (MAPK) activities, which provided immediate and early signals for the transient expression of these two kinases. Genomic mapping identified an enhancer element within the first intron of the NUAK2 gene that can recruit SMAD proteins, which, when cloned, could confer induction by TGFβ. Furthermore, NUAK2 formed protein complexes with SMAD3 and the TGFβ type I receptor. Functionally, NUAK1 suppressed and NUAK2 induced TGFβ signaling. This was evident during TGFβ-induced epithelial cytostasis, mesenchymal differentiation and myofibroblast contractility, in which NUAK1 or NUAK2 silencing enhanced or inhibited these responses, respectively. In conclusion, we have identified a bifurcating loop during TGFβ signaling, whereby transcriptional induction of NUAK1 serves as a negative checkpoint and NUAK2 induction positively contributes to signaling and terminal differentiation responses to TGFβ activity.
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| 8. |
- Lin, Chun-Yu, et al.
(författare)
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High levels of serum hyaluronan is an early predictor of dengue warning signs and perturbs vascular integrity
- 2019
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Ingår i: EBioMedicine. - : ELSEVIER. - 2352-3964. ; 48, s. 425-441
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Tidskriftsartikel (refereegranskat)abstract
- Background: A main pathological feature of severe dengue virus infection is endothelial hyper-permeability. The dengue virus nonstructural protein 1 (NS1) has been implicated in the vascular leakage that characterizes severe dengue virus infection, however, the molecular mechanisms involved are not known.Methods: A cohort of 250 dengue patients has been followed from the onset of symptoms to the recovery phase. Set urn hyaluronan levels and several other clinical parameters were recorded. The effect of NS1 treatment of cultured fibroblasts and endothelial cells on the expressions of hyaluronan synthetic and catabolic enzymes and the hyaluronan receptor CD44, were determined, as have the effects on the formation of hyaluronan-rich matrices and endothelial permeability.Findings: Elevated serum hyaluronan levels (70 ng/ml) during early infection was found to be an independent predictor for occurrence of warning signs, and thus severe dengue fever. High circulating levels of the viral protein NS1, indicative of disease severity, correlated with high concentrations of serum hyaluronan. NS1 exposure decreased the expression of CD44 in differentiating endothelial cells impairing the integrity of vessel-like structures, and promoted the synthesis of hyaluronan in dermal fibroblasts and endothelial cells in synergy with dengue-induced pro-inflammatory mediators. Deposited hyaluronan-rich matrices around cells cultured in vitro recruited CD44-expressing macrophage-like cells, suggesting a mechanism for enhancement of inflammation. In cultured endothelial cells, perturbed hyaluronan-CD44 interactions enhanced endothelial permeability through modulation of VE-cadherin and cytoskeleton re-organization, and exacerbated the NS1-induced disruption of endothelial integrity.Interpretation: Pharmacological targeting of hyaluronan biosynthesis and/or its CD44-mediated signaling may limit the life-threatening vascular leakiness during moderate-to-severe dengue virus infection.
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| 9. |
- Lin, Chun-Yu, et al.
(författare)
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Hyaluronan-Induced CD44-iASPP Interaction Affects Fibroblast Migration and Survival
- 2023
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 15:4
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, we show that the inhibitor of the apoptosis-stimulating protein of p53 (iASPP) physically interacts with the hyaluronan receptor CD44 in normal and transformed cells. We noticed that the CD44 standard isoform (CD44s), but not the variant isoform (CD44v), bound to iASPP via the ankyrin-binding domain in CD44s. The formation of iASPP-CD44s complexes was promoted by hyaluronan stimulation in fibroblasts but not in epithelial cells. The cellular level of p53 affected the amount of the iASPP-CD44 complex. iASPP was required for hyaluronan-induced CD44-dependent migration and adhesion of fibroblasts. Of note, CD44 altered the sub-cellular localization of the iASPP-p53 complex; thus, ablation of CD44 promoted translocation of iASPP from the nucleus to the cytoplasm, resulting in increased formation of a cytoplasmic iASPP-p53 complex in fibroblasts. Overexpression of iASPP decreased, but CD44 increased the level of intracellular reactive oxygen species (ROS). Knock-down of CD44s, in the presence of p53, led to increased cell growth and cell density of fibroblasts by suppression of p27 and p53. Our observations suggest that the balance of iASPP-CD44 and iASPP-p53 complexes affect the survival and migration of fibroblasts.
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| 10. |
- Mehic, Merima, Sr., et al.
(författare)
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The role of deubiquitinating enzyme USP17, hyaluronan synthase 2, and hyaluronan in non-small-cell lung cancer oncogenic transformation
- 2018
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 24:1, s. 96-96
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Lung cancer is the result of a multistep accumulation of genetic and/or epigenetic alterations; therefore, a better understanding of the molecular mechanism by which these alterations affect lung cancer pathogenesis would provide new diagnostic procedures and prognostic factors for early detection of recurrence. The remarkable qualitative and quantitative modifications of extracellular matrix components as the deubiquitinating enzyme (USP17), hyaluronan (HA), and hyaluronan synthases 2 (HAS 2) may favor invasion, cellular motility, and proliferation in several cancers including lung.Results: The silencing of USP17 led to decreased hyaluronan production, whereas the suppression of USP4 increased hyaluronan synthesis. Importantly, high levels of USP17 and HAS2 were detected in a panel of cancer cell lines compared to normal cells, and immunohistochemical stainings revealed higher expression of USP17 and HAS2 in tissues of lung cancer patients compared to normal tissue. Numerous epithelial cells expressed USP17 and HAS2 in dysplasia compared to squamous cell carcinoma (SqCC) (p=0.001). USP17 and HAS2 were prominently expressed in adenocarcinoma (ADC) (p≤0.005). HA immunostaining indexes were increased in ADC and SqCC compared to normal and dysplasia cells (p=0.05). Consistent with the immunohistochemical analyses, low amounts of hyaluronan and USP17 were observed in SqCC by confocal analysis, coincident with less colocalization as determined by confocal microscopy. In contrast, a high expression of hyaluronan (48% of positive index) and high USP17 expression (78% of positive index) in ADC was consistent with a higher degree of colocalization.Conclusions: HAS2, hyaluronan and USP17 were expressed at higher levels in particular in preneoplastic lesions and ADC, suggesting a role in NSCLC oncogenic transformation, possibly by promoting cellular division by USP17-mediated. Elucidation of the mechanism of how USP17 and HAS2 cooperate in the regulation of the cell cycle might be of therapeutic importance.
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| 11. |
- Mehić, Merima, et al.
(författare)
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The deubiquitinating enzymes USP4 and USP17 target hyaluronan synthase 2 and differentially affect its function
- 2017
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Ingår i: Oncogenesis. - : Springer Science and Business Media LLC. - 2157-9024. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- The levels of hyaluronan, a ubiquitous glycosaminoglycan prominent in the extracellular matrix, is balanced through the actions of hyaluronan-synthesizing enzymes (HAS1, 2 and 3) and degrading hyaluronidases (Hyal 1, 2, 3 and PH20). Hyaluronan accumulates in rapidly remodeling tissues, such as breast cancer, due to deregulated expression of the HAS2 gene and/or alterations of HAS2 activity. The activity of HAS2 is regulated by post-translational modifications, including ubiquitination. In order to identify deubiquitinating enzymes (DUBs) that are involved in de-ubiquitination of HAS2, a complementary (cDNA) library of 69 Flag-HA-tagged human DUBs cloned into retroviral vectors was screened in human embryonic kidney (HEK) 293T cells for their ability to de-ubiquitinate myc-tagged HAS2. Several DUBs were found to decrease the ubiquitination of 6myc-HAS2, among which, the most effective were USP17 and USP4. USP17 efficiently removed polyubiquitination, whereas USP4 preferentially removed monoubiquitination of 6myc-HAS2. Co-immunoprecipitation studies revealed interactions between HAS2 and USP17, as well as between HAS2 and USP4, in membrane preparations of HEK293T cells. USP17 significantly stabilized 6myc-HAS2 protein levels, whereas USP4 did not. The silencing of USP17 led to decreased hyaluronan production, whereas the suppression of USP4 increased hyaluronan synthesis. Importantly, high levels of USP17 and HAS2 were detected in a panel of cancer cell lines compared to normal cells, and immunohistochemical stainings revealed higher expression of USP17 and HAS2 in tissues of lung cancer patients compared to normal tissue. In conclusion, USP17 and USP4 differently affect HAS2 ubiquitination, and the stability and function of HAS2.
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| 12. |
- Amagasaki, Kenichi, et al.
(författare)
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c-Jun N-terminal kinase is necessary for platelet-derived growth factor-mediated chemotaxis in primary fibroblasts
- 2006
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Ingår i: Journal of Biological Chemistry. - : The American Society for Biochemistry and Molecular Biology, Inc.. - 0021-9258 .- 1083-351X. ; 281:31, s. 22173-22179
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Tidskriftsartikel (refereegranskat)abstract
- c-Jun N-terminal kinase (JNK) is a member of the mitogen-activated protein kinase family. It has become clear that JNK does not only have a role in induction of stress responses but also in processes such as cell movement. In this report we demonstrate that JNK activity is necessary for platelet-derived growth factor (PDGF)-BB-induced chemotaxis of primary foreskin fibroblasts and in other cell types. PDGF-BB stimulation was found to lead to activation of JNK with a maximum after 30 min. Inhibition of JNK reduced Ser178 phosphorylation of the focal adhesion component paxillin. Paxillin phosphorylation at this site has been shown to be involved in the dynamics of focal adhesions and consequently cell migration. Moreover, we observed localization of JNK to the actin-dense membrane ruffles induced by PDGF-BB stimulation both using immunofluorescence staining and green fluorescent protein-tagged JNK. This suggests a role for JNK at the leading edge of the cell compatible with a function in cell migration. Furthermore, we show that phosphatidylinositol 3-kinase (PI 3-kinase), which has an established role in PDGF-stimulated cell migration, is necessary for PDGF-induced activation of JNK. In conclusion, JNK is a critical component downstream of PI 3-kinase that may be involved in PDGF-stimulated chemotaxis presumably by modulating the integrity of focal adhesions by phosphorylating its components.
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| 13. |
- Bellomo, Claudia, et al.
(författare)
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Snail mediates crosstalk between TGFβ and LXRα in hepatocellular carcinoma
- 2018
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Ingår i: Cell Death and Differentiation. - : Springer Science and Business Media LLC. - 1350-9047 .- 1476-5403. ; 25:5, s. 885-903
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the complexity of changes in differentiation and cell survival in hepatocellular carcinoma (HCC) is essential for the design of new diagnostic tools and therapeutic modalities. In this context, we have analyzed the crosstalk between transforming growth factor β (TGFβ) and liver X receptor α (LXRα) pathways. TGFβ is known to promote cytostatic and pro-apoptotic responses in HCC, and to facilitate mesenchymal differentiation. We here demonstrate that stimulation of the nuclear LXRα receptor system by physiological and clinically useful agonists controls the HCC response to TGFβ. Specifically, LXRα activation antagonizes the mesenchymal, reactive oxygen species and pro-apoptotic responses to TGFβ and the mesenchymal transcription factor Snail mediates this crosstalk. In contrast, LXRα activation and TGFβ cooperate in enforcing cytostasis in HCC, which preserves their epithelial features. LXRα influences Snail expression transcriptionally, acting on the Snail promoter. These findings propose that clinically used LXR agonists may find further application to the treatment of aggressive, mesenchymal HCCs, whose progression is chronically dependent on autocrine or paracrine TGFβ.
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| 14. |
- Burmakin, Mikhail, et al.
(författare)
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Imatinib increases oxygen delivery in extracellular matrix-rich but not in matrix-poor experimental carcinoma
- 2017
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Ingår i: Journal of Translational Medicine. - : BioMed Central. - 1479-5876. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- Background: Imatinib causes increased turnover of stromal collagen, reduces collagen fibril diameter, enhances extracellular fluid turnover and lowers interstitial fluid pressure (IFP) in the human colonic carcinoma KAT-4/HT-29 (KAT-4) xenograft model. Methods: We compared the effects of imatinib on oxygen levels, vascular morphology and IFP in three experimental tumor models differing in their content of a collagenous extracellular matrix. Results: Neither the KAT4 and CT-26 colonic carcinoma models, nor B16BB melanoma expressed PDGF beta-receptors in the malignant cells. KAT-4 tumors exhibited a well-developed ECM in contrast to the other two model systems. The collagen content was substantially higher in KAT-4 than in CT-26, while collagen was not detectable in B16BB tumors. The pO(2) was on average 5.4, 13.9 and 19.3 mmHg in KAT-4, CT-26 and B16BB tumors, respectively. Treatment with imatinib resulted in similar pO(2)-levels in all three tumor models but only in KAT-4 tumors did the increase reach statistical significance. It is likely that after imatinib treatment the increase in pO(2) in KAT-4 tumors is caused by increased blood flow due to reduced vascular resistance. This notion is supported by the significant reduction observed in IFP in KAT-4 tumors after imatinib treatment. Vessel area varied between 4.5 and 7% in the three tumor models and was not affected by imatinib treatment. Imatinib had no effect on the fraction of proliferating cells, whereas the fraction of apoptotic cells increased to a similar degree in all three tumor models. Conclusion: Our data suggest that the effects of imatinib on pO(2)-levels depend on a well-developed ECM and provide further support to the suggestion that imatinib acts by causing interstitial stroma cells to produce a less dense ECM, which would in turn allow for an increased blood flow. The potential of imatinib treatment to render solid tumors more accessible to conventional treatments would therefore depend on the degree of tumor desmoplasia.
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| 15. |
- Caja, Laia, et al.
(författare)
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Snail regulates BMP and TGF beta pathways to control the differentiation status of glioma-initiating cells
- 2018
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 37:19, s. 2515-2531
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Tidskriftsartikel (refereegranskat)abstract
- Glioblastoma multiforme is a brain malignancy characterized by high heterogeneity, invasiveness, and resistance to current therapies, attributes related to the occurrence of glioma stem cells (GSCs). Transforming growth factor beta (TGF beta) promotes self-renewal and bone morphogenetic protein (BMP) induces differentiation of GSCs. BMP7 induces the transcription factor Snail to promote astrocytic differentiation in GSCs and suppress tumor growth in vivo. We demonstrate that Snail represses stemness in GSCs. Snail interacts with SMAD signaling mediators, generates a positive feedback loop of BMP signaling and transcriptionally represses the TGFB1 gene, decreasing TGF beta 1 signaling activity. Exogenous TGF beta 1 counteracts Snail function in vitro, and in vivo promotes proliferation and re-expression of Nestin, confirming the importance of TGFB1 gene repression by Snail. In conclusion, novel insight highlights mechanisms whereby Snail differentially regulates the activity of the opposing BMP and TGF beta pathways, thus promoting an astrocytic fate switch and repressing stemness in GSCs.
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| 16. |
- Caja, Laia, et al.
(författare)
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The protein kinase LKB1 promotes self-renewal and blocks invasiveness in glioblastoma
- 2022
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Ingår i: Journal of Cellular Physiology. - : John Wiley & Sons. - 0021-9541 .- 1097-4652. ; 237:1, s. 743-762
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Tidskriftsartikel (refereegranskat)abstract
- The role of liver kinase B1 (LKB1) in glioblastoma (GBM) development remains poorly understood. LKB1 may regulate GBM cell metabolism and has been suggested to promote glioma invasiveness. After analyzing LKB1 expression in GBM patient mRNA databases and in tumor tissue via multiparametric immunohistochemistry, we observed that LKB1 was localized and enriched in GBM tumor cells that co-expressed SOX2 and NESTIN stemness markers. Thus, LKB1-specific immunohistochemistry can potentially reveal subpopulations of stem-like cells, advancing GBM patient molecular pathology. We further analyzed the functions of LKB1 in patient-derived GBM cultures under defined serum-free conditions. Silencing of endogenous LKB1 impaired 3D-gliomasphere frequency and promoted GBM cell invasion in vitro and in the zebrafish collagenous tail after extravasation of circulating GBM cells. Moreover, loss of LKB1 function revealed mitochondrial dysfunction resulting in decreased ATP levels. Treatment with the clinically used drug metformin impaired 3D-gliomasphere formation and enhanced cytotoxicity induced by temozolomide, the primary chemotherapeutic drug against GBM. The IC50 of temozolomide in the GBM cultures was significantly decreased in the presence of metformin. This combinatorial effect was further enhanced after LKB1 silencing, which at least partially, was due to increased apoptosis. The expression of genes involved in the maintenance of tumor stemness, such as growth factors and their receptors, including members of the platelet-derived growth factor (PDGF) family, was suppressed after LKB1 silencing. The defect in gliomasphere growth caused by LKB1 silencing was bypassed after supplementing the cells with exogenous PFDGF-BB. Our data support the parallel roles of LKB1 in maintaining mitochondrial homeostasis, 3D-gliomasphere survival, and hindering migration in GBM. Thus, the natural loss of, or pharmacological interference with LKB1 function, may be associated with benefits in patient survival but could result in tumor spread.
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| 17. |
- Christian, Jan L., et al.
(författare)
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The TGFβ superfamily in Lisbon : navigating through development and disease
- 2017
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Ingår i: Development. - : The Company of Biologists. - 0950-1991 .- 1477-9129. ; 144:24, s. 4476-4480
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The 10th FASEB meeting ‘The TGFβ Superfamily: Signaling in Development and Disease' took place in Lisbon, Portugal, in July 2017. As we review here, the findings presented at the meeting highlighted the important contributions of TGFβ family signaling to normal development, adult homeostasis and disease, and also revealed novel mechanisms by which TGFβ signals are transduced.
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| 18. |
- Cunha, Sara I, et al.
(författare)
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Genetic and pharmacological targeting of activin receptor-like kinase 1 impairs tumor growth and angiogenesis
- 2010
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Ingår i: Journal of Experimental Medicine. - : The Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 207:1, s. 85-100
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Tidskriftsartikel (refereegranskat)abstract
- Members of the transforming growth factor beta (TGF-beta) family have been genetically linked to vascular formation during embryogenesis. However, contradictory studies about the role of TGF-beta and other family members with reported vascular functions, such as bone morphogenetic protein (BMP) 9, in physiological and pathological angiogenesis make the need for mechanistic studies apparent. We demonstrate, by genetic and pharmacological means, that the TGF-beta and BMP9 receptor activin receptor-like kinase (ALK) 1 represents a new therapeutic target for tumor angiogenesis. Diminution of ALK1 gene dosage or systemic treatment with the ALK1-F(c) fusion protein RAP-041 retarded tumor growth and progression by inhibition of angiogenesis in a transgenic mouse model of multistep tumorigenesis. Furthermore, RAP-041 significantly impaired the in vitro and in vivo angiogenic response toward vascular endothelial growth factor A and basic fibroblast growth factor. In seeking the mechanism for the observed effects, we uncovered an unexpected signaling synergy between TGF-beta and BMP9, through which the combined action of the two factors augmented the endothelial cell response to angiogenic stimuli. We delineate a decisive role for signaling by TGF-beta family members in tumor angiogenesis and offer mechanistic insight for the forthcoming clinical development of drugs blocking ALK1 in oncology.
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| 19. |
- Ekman, Maria, 1979-, et al.
(författare)
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APC and Smad7 link TGF beta type I receptors to the microtubule system to promote cell migration
- 2012
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Ingår i: Molecular Biology of the Cell. - : American Society of Cell Biology, USA. - 1059-1524 .- 1939-4586. ; 23:11, s. 2109-2121
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Tidskriftsartikel (refereegranskat)abstract
- Cell migration occurs by activation of complex regulatory pathways that are spatially and temporally integrated in response to extracellular cues. Binding of adenomatous polyposis coli (APC) to the microtubule plus ends in polarized cells is regulated by glycogen synthase kinase 3 beta (GSK-3 beta). This event is crucial for establishment of cell polarity during directional migration. However, the role of APC for cellular extension in response to extracellular signals is less clear. Smad7 is a direct target gene for transforming growth factor-beta (TGF beta) and is known to inhibit various TGF beta-induced responses. Here we report a new function for Smad7. We show that Smad7 and p38 mitogen-activated protein kinase together regulate the expression of APC and cell migration in prostate cancer cells in response to TGF beta stimulation. In addition, Smad7 forms a complex with APC and acts as an adaptor protein for p38 and GSK-3 beta kinases to facilitate local TGF beta/p38-dependent inactivation of GSK-3 beta, accumulation of beta-catenin, and recruitment of APC to the microtubule plus end in the leading edge of migrating prostate cancer cells. Moreover, the Smad7-APC complex links the TGF beta type I receptor to the microtubule system to regulate directed cellular extension and migratory responses evoked by TGF beta.
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| 20. |
- Fukuda, Tomohiko, et al.
(författare)
-
BMP signaling is a therapeutic target in ovarian cancer
- 2020
-
Ingår i: Cell Death Discovery. - : Springer Science and Business Media LLC. - 2058-7716. ; 6:1
-
Tidskriftsartikel (refereegranskat)abstract
- BMP signaling has been found to have tumor-promoting as well as tumor-suppressing effects in different types of tumors. In this study, we investigated the effects of BMP signaling and of BMP inhibitors on ovarian cancer (OC) cells in vitro and in vivo. High expression of BMP receptor 2 (BMPR2) correlated with poor overall survival of OC patients in the TCGA dataset. Both BMP2 and BMPR2 enhanced OC cell proliferation, whereas BMP receptor kinase inhibitors inhibited OC cell growth in cell culture as well as in a mouse model. BMP2 also augmented sphere formation, migration, and invasion of OC cells, and induced EMT. High BMP2 expression was observed after chemotherapy of OC patients in the GSE109934 dataset. In accordance, carboplatin, used for the treatment of OC patients, increased BMP2 secretion from OC cells, and induced EMT partially via activation of BMP signaling. Our data suggest that BMP signaling has tumor-promoting effects in OC, and that BMP inhibitors might be useful therapeutic agents for OC patients. Considering that carboplatin treatment augmented BMP2 secretion, the possibility to use a combination of BMP inhibitors and carboplatin in the treatment of OC patients, would be worth exploring.
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| 21. |
- Fukuda, Tomohiko, et al.
(författare)
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BMP2-induction of FN14 promotes protumorigenic signaling in gynecologic cancer cells
- 2021
-
Ingår i: Cellular Signalling. - : Elsevier. - 0898-6568 .- 1873-3913. ; 87
-
Tidskriftsartikel (refereegranskat)abstract
- We previously reported that bone morphogenetic protein (BMP) signaling promotes tumorigenesis in gynecologic cancer cells. BMP2 enhances proliferation of ovarian and endometrial cancer cells via c-KIT induction, and triggers epithelial-mesenchymal transition (EMT) by SNAIL and/or SLUG induction, leading to increased cell migration. However, the downstream effectors of BMP signaling in gynecological cancer cells have not been clearly elucidated. In this study, we performed RNA-sequencing of Ishikawa endometrial and SKOV3 ovarian cancer cells after BMP2 stimulation, and identified TNFRSF12A, encoding fibroblast growth factor-inducible 14 (FN14) as a common BMP2-induced gene. FN14 knockdown suppressed BMP2-induced cell proliferation and migration, confirmed by MTS and scratch assays, respectively. In addition, FN14 silencing augmented chemosensitivity of SKOV3 cells. As a downstream effector of BMP signaling, FN14 modulated both c-KIT and SNAIL expression, which are important for growth and migration of ovarian and endometrial cancer cells. These results support the notion that the tumor promoting effects of BMP signaling in gynecological cancers are partially attributed to FN14 induction.
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| 22. |
- Fukuda, Tomohiko, et al.
(författare)
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Tumor Promoting Effect of BMP Signaling in Endometrial Cancer
- 2021
-
Ingår i: International Journal of Molecular Sciences. - : MDPI. - 1661-6596 .- 1422-0067. ; 22:15
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of bone morphogenetic proteins (BMPs), members of the transforming growth factor-beta (TGF-beta) family, in endometrial cancer (EC) have yet to be determined. In this study, we analyzed the TCGA and MSK-IMPACT datasets and investigated the effects of BMP2 and of TWSG1, a BMP antagonist, on Ishikawa EC cells. Frequent ACVR1 mutations and high mRNA expressions of BMP ligands and receptors were observed in EC patients of the TCGA and MSK-IMPACT datasets. Ishikawa cells secreted higher amounts of BMP2 compared with ovarian cancer cell lines. Exogenous BMP2 stimulation enhanced EC cell sphere formation via c-KIT induction. BMP2 also induced EMT of EC cells, and promoted migration by induction of SLUG. The BMP receptor kinase inhibitor LDN193189 augmented the growth inhibitory effects of carboplatin. Analyses of mRNAs of several BMP antagonists revealed that TWSG1 mRNA was abundantly expressed in Ishikawa cells. TWSG1 suppressed BMP7-induced, but not BMP2-induced, EC cell sphere formation and migration. Our results suggest that BMP signaling promotes EC tumorigenesis, and that TWSG1 antagonizes BMP7 in EC. BMP signaling inhibitors, in combination with chemotherapy, might be useful in the treatment of EC patients.
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| 23. |
- Gélabert, Caroline, et al.
(författare)
-
Glutamine deprivation alters TGF-β signaling in hepatocellular carcinoma
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Metabolic reprogramming is one of the hallmarks of cancer. Glutamine is one of the most important nutrients that fuels the TCA cycle and therefore takes part in the production of energy. Glutamine is used as starting metabolite for the synthesis of nucleotides, fatty acids and nonessential amino acids. Since nutrients are uptaken from the blood stream, and considering the 3- dimensional state of solid tumors, access of nutrients is highly dependent on the location of individual cells within a tumor, which results in affecting their metabolic activity. This gives rise to two disctincts cell population: the ones that have access to nutrient and the ones that are nutrientdeprived. We studied the effect of the lack of glutamine by creating glutamine-resistent hepatocellular carcinoma cell lines chosen based on their epithelial (Hep3B) or mesenchymal phenotype (SNU-499 and HLF). We found that glutamine deprivation decreased the proliferation rate, clonogenicity and stemness frequency of the three cell lines but in a greater extent of the mesenchymal cells. Transcriptomic analysis performed in HLF cells showed that glutamine deprivation decreased the activation of signaling pathways involved in cell-cell junction, cellextracellular matrix interactions and decreased the expression of the hallmarks of epithelial-tomesenchymal transition. We therefore investigated the role of TGFβ, a master regulator of these three processes, by transcriptomic and functional analyses in epithelial (Hep3B) and mesenchymal cells (HLF). We found that the lack of glutamine strongly impared the activation of TGFβ signaling which correlated with an altered regulation of TGFβ target genes: the expression of mesenchymal genes was no longer induced by TGFβ while the epithelial genes were more strongly induced. Functional analyses showed that glutamine deprivation abolished the invasive capacities of HCCs and decreased cell adhesion. Altogehter, our results show that glutamine metabolism is necessary to maintain a mesenchymal phenotype and to maintain an efficient TGFβ signaling in hepatocellularcarcinoma.
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| 24. |
- Gélabert, Caroline, et al.
(författare)
-
The long non-coding RNA LINC00707 interacts with Smad proteins to regulate TGFβ signaling and cancer cell invasion
- 2023
-
Ingår i: Cell Communication and Signaling. - : BioMed Central (BMC). - 1478-811X.
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Long non-coding RNAs (lncRNAs) regulate cellular processes by interacting with RNAs or proteins. Transforming growth factor β (TGFβ) signaling via Smad proteins regulates gene networks that control diverse biological processes, including cancer cell migration. LncRNAs have emerged as TGFβ targets, yet, their mechanism of action and biological role in cancer remains poorly understood.Methods: Whole-genome transcriptomics identified lncRNA genes regulated by TGFβ. Protein kinase inhibitors and RNA-silencing, in combination with cDNA cloning, provided loss- and gain-of-function analyses. Cancer cell-based assays coupled to RNA-immunoprecipitation and protein screening sought mechanistic evidence. Functional validation of TGFβ-regulated lncRNAs was based on new transcriptomics and by combining RNAscope with immunohistochemical analysis in tumor tissue.Results: Transcriptomics of TGFβ signaling responses revealed down-regulation of the predominantly cytoplasmic long intergenic non-protein coding RNA 707 (LINC00707). Expression of LINC00707 required Smad and mitogen-activated protein kinase inputs. By limiting the binding of Krüppel-like factor 6 to the LINC00707 promoter, TGFβ led to LINC00707 repression. Functionally, LINC00707 suppressed cancer cell invasion, as well as key fibrogenic and pro-mesenchymal responses to TGFβ, as also attested by RNA-sequencing analysis. LINC00707 also suppressed Smad-dependent signaling. Mechanistically, LINC00707 interacted with and retained Smad proteins in the cytoplasm. Upon TGFβ stimulation, LINC00707 elimination allowed Smad accumulation in the nucleus. In vivo, LINC00707 expression was negatively correlated with Smad2 activation in tumor tissues.Conclusions: TGFβ signaling decreases LINC00707 expression, which facilitates Smad-dependent signaling, favoring cancer cell invasion.
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| 25. |
- Gudey, Shyam Kumar, et al.
(författare)
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Pro-invasive properties of Snail1 are regulated by sumoylation in response to TGFβ stimulation in cancer
- 2017
-
Ingår i: Oncotarget. - : IMPACT JOURNALS LLC. - 1949-2553. ; 8:58, s. 97703-97726
-
Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor beta (TGF beta) is a key regulator of epithelial-tomesenchymal transition (EMT) during embryogenesis and in tumors. The effect of TGF beta, on EMT, is conveyed by induction of the pro-invasive transcription factor Snail1. In this study, we report that TGF beta stimulates Snail1 sumoylation in aggressive prostate, breast and lung cancer cells. Sumoylation of Snail1 lysine residue 234 confers its transcriptional activity, inducing the expression of classical EMT genes, as well as TGF beta receptor I (T beta RI) and the transcriptional repressor Hes1. Mutation of Snail1 lysine residue 234 to arginine (K234R) abolished sumoylation of Snail1, as well as its migratory and invasive properties in human prostate cancer cells. An increased immunohistochemical expression of Snail1, Sumo1, T beta RI, Hes1, and c-Jun was observed in aggressive prostate cancer tissues, consistent with their functional roles in tumorigenesis.
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| 26. |
- Hamidi, Anahita, et al.
(författare)
-
Polyubiquitination of transforming growth factor β (TGFβ)-associated kinase 1 mediates nuclear factor-κB activation in response to different inflammatory stimuli
- 2012
-
Ingår i: Journal of Biological Chemistry. - : The American Society for Biochemistry and Molecular Biology, Inc.. - 0021-9258 .- 1083-351X. ; 287:1, s. 123-133
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Tidskriftsartikel (refereegranskat)abstract
- The transcription factor nuclear factor κB (NF-κB) plays a central role in regulating inflammation in response to several external signals. The TGFβ-associated kinase 1 (TAK1) is an upstream regulator of NF-κB signaling. In TGFβ-stimulated cells, TAK1 undergoes Lys-63-linked polyubiquitination at Lys-34 by TNF receptor-associated factor 6 and is thereby activated. The aim of this study was to investigate whether TAK1 polyubiquitination at Lys-34 is also essential for NF-κB activation via TNF receptor, IL-1 receptor and toll-like receptor 4. We observed that TAK1 polyubiquitination occurred at Lys-34 and required the E3 ubiquitin ligase TNF receptor-associated factor 6 after stimulation of cells with IL-1β. Polyubiquitination of TAK1 also occurred at Lys-34 in cells stimulated by TNF-α and LPS, which activates TLR4, as well as in HepG2 and prostate cancer cells stimulated with TGFβ, which in all cases resulted in NF-κB activation. Expression of a K34R-mutant TAK1 led to a reduced NF-κB activation, IL-6 promoter activity, and proinflammatory cytokine secretion by TNF-α-stimulated PC-3U cells. Similar results were obtained in the mouse macrophage cell line RAW264.7 after LPS treatment. In conclusion, polyubiquitination of TAK1 is correlated with activation of TAK1 and is essential for activation of NF-κB signaling downstream of several receptors.
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| 27. |
- Hamidi, Anahita, et al.
(författare)
-
TGF-β promotes PI3K-AKT signaling and prostate cancer cell migration through the TRAF6-mediated ubiquitylation of p85α
- 2017
-
Ingår i: Science Signaling. - : American Association for the Advancement of Science. - 1945-0877 .- 1937-9145. ; 10:486
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- TGF-β signaling stimulates various intracellular pathways that can promote migration in tumor cells. These pathways are generally thought to be either dependent or independent of transcription factors called SMADs. One of the SMAD-independent pathways (PI3K-AKT) is mediated by a direct interaction between PI3K and the TGF-β type I receptor. However, Hamidi et al. found that the TGF-β–induced activation of PI3K depends on another ubiquitin ligase–mediated mechanism and a SMAD protein but is independent of the kinase function of TβRI. The binding of TGF-β to its receptor triggered the recruitment of PI3K and the ubiquitin ligase TRAF6, which polyubiquitylated the regulatory PI3K subunit p85α, thus enabling phosphorylation of the catalytic PI3K subunit p110, but only in the presence of SMAD7. The abundance of ubiquitylated p85α correlated with migration in cultured cells and prostate tumor grade in patient samples. TRAF6 mediates activation of the other “SMAD-independent” (JNK) pathway. These data suggest that, although distinct, the TGF-β signaling pathways are not as insulated from each other as was once thought.
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| 28. |
- Heldin, Carl-Henrik, 1952-, et al.
(författare)
-
Involvement of platelet-derived growth factor ligands and receptors in tumorigenesis
- 2018
-
Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 283:1, s. 16-44
-
Forskningsöversikt (refereegranskat)abstract
- Platelet-derived growth factor (PDGF) isoforms and their receptors have important roles during embryogenesis, particularly in the development of various mesenchymal cell types in different organs. In the adult, PDGF stimulates wound healing and regulates tissue homeostasis. However, overactivity of PDGF signalling is associated with malignancies and other diseases characterized by excessive cell proliferation, such as fibrotic conditions and atherosclerosis. In certain tumours, genetic or epigenetic alterations of the genes for PDGF ligands and receptors drive tumour cell proliferation and survival. Examples include the rare skin tumour dermatofibrosarcoma protuberance, which is driven by autocrine PDGF stimulation due to translocation of a PDGF gene, and certain gastrointestinal stromal tumours and leukaemias, which are driven by constitute activation of PDGF receptors due to point mutations and formation of fusion proteins ofthe receptors, respectively. Moreover, PDGF stimulates cells in tumour stroma and promotes angiogenesis as well as the development of cancer-associated fibroblasts, both of which promote tumour progression. Inhibitors of PDGF signalling may thus be of clinical usefulness in the treatment of certain tumours.
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| 29. |
- Heldin, Carl-Henrik, 1952-, et al.
(författare)
-
Mechanism of action and in vivo role of platelet-derived growth factor
- 1999
-
Ingår i: Physiological Reviews. - 0031-9333 .- 1522-1210. ; 79:4, s. 1283-1316
-
Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor (PDGF) is a major mitogen for connective tissue cells and certain other cell types. It is a dimeric molecule consisting of disulfide-bonded, structurally similar A- and B-polypeptide chains, which combine to homo- and heterodimers. The PDGF isoforms exert their cellular effects by binding to and activating two structurally related protein tyrosine kinase receptors, denoted the alpha-receptor and the beta-receptor. Activation of PDGF receptors leads to stimulation of cell growth, but also to changes in cell shape and motility; PDGF induces reorganization of the actin filament system and stimulates chemotaxis, i.e., a directed cell movement toward a gradient of PDGF. In vivo, PDGF has important roles during the embryonic development as well as during wound healing. Moreover, overactivity of PDGF has been implicated in several pathological conditions. The sis oncogene of simian sarcoma virus (SSV) is related to the B-chain of PDGF, and SSV transformation involves autocrine stimulation by a PDGF-like molecule. Similarly, overproduction of PDGF may be involved in autocrine and paracrine growth stimulation of human tumors. Overactivity of PDGF has, in addition, been implicated in nonmalignant conditions characterized by an increased cell proliferation, such as atherosclerosis and fibrotic conditions. This review discusses structural and functional properties of PDGF and PDGF receptors, the mechanism whereby PDGF exerts its cellular effects, and the role of PDGF in normal and diseased tissues.
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| 30. |
|
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| 31. |
- Heldin, Carl-Henrik, 1952-, et al.
(författare)
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Role of Smads in TGFβ signaling
- 2012
-
Ingår i: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 0302-766X .- 1432-0878. ; 347:1, s. 21-36
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Forskningsöversikt (refereegranskat)abstract
- Transforming growth factor-β (TGFβ) is the prototype for a large family of pleiotropic factors that signal via heterotetrameric complexes of type I and type II serine/threonine kinase receptors. Important intracellular mediators of TGFβ signaling are members of the Smad family. Smad2 and 3 are activated by C-terminal receptor-mediated phosphorylation, whereafter they form complexes with Smad4 and are translocated to the nucleus where they, in cooperation with other transcription factors, co-activators and co-repressors, regulate the transcription of specific genes. Smads have key roles in exerting TGFβ-induced programs leading to cell growth arrest and epithelial-mesenchymal transition. The activity and stability of Smad molecules are carefully regulated by a plethora of post-translational modifications, including phosphorylation, ubiquitination, sumoylation, acetylation and poly(ADP)-ribosylation. The Smad function has been shown to be perturbed in certain diseases such as cancer.
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| 32. |
- Heldin, Carl-Henrik, 1952-, et al.
(författare)
-
Signals and receptors
- 2014
-
Ingår i: Signal transduction. - New York : Cold Spring Harbor Laboratory Press (CSHL). - 9780879699017 ; , s. 3-29
-
Bokkapitel (refereegranskat)
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| 33. |
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| 34. |
- Hellberg, Carina, et al.
(författare)
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Activation of Protein Kinase C α Is Necessary for Sorting the PDGF β-Receptor to Rab4a-dependent Recycling
- 2009
-
Ingår i: Molecular Biology of the Cell. - 1059-1524 .- 1939-4586. ; 20:12, s. 2856-2863
-
Tidskriftsartikel (refereegranskat)abstract
- Previous studies showed that loss of the T-cell protein tyrosine phosphatase (TC-PTP) induces Rab4a-dependent recycling of the platelet-derived growth factor (PDGF) β-receptor in mouse embryonic fibroblasts (MEFs). Here we identify protein kinase C (PKC) α as the critical signaling component that regulates the sorting of the PDGF β-receptor at the early endosomes. Down-regulation of PKC abrogated receptor recycling by preventing the sorting of the activated receptor into EGFP-Rab4a positive domains on the early endosomes. This effect was mimicked by inhibition of PKCα, using myristoylated inhibitory peptides or by knockdown of PKCα with shRNAi. In wt MEFs, short-term preactivation of PKC by PMA caused a ligand-induced PDGF β-receptor recycling that was dependent on Rab4a function. Together, these observations demonstrate that PKC activity is necessary for recycling of ligand-stimulated PDGF β-receptor to occur. The sorting also required Rab4a function as it was prevented by expression of EGFP-Rab4aS22N. Preventing receptor sorting into recycling endosomes increased the rate of receptor degradation, indicating that the sorting of activated receptors at early endosomes directly regulates the duration of receptor signaling. Activation of PKC through the LPA receptor also induced PDGF β-receptor recycling and potentiated the chemotactic response to PDGF-BB. Taken together, our present findings indicate that sorting of PDGF β-receptors on early endosomes is regulated by sequential activation of PKCα and Rab4a and that this sorting step could constitute a point of cross-talk with other receptors.
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| 35. |
- Hellberg, Carina, et al.
(författare)
-
PDGF and Vessel Maturation
- 2010
-
Ingår i: Angiogenesis inhibition. - Berlin, Heidelberg : Springer-Verlag Berlin Heidelberg. - 9783540782803 ; 180, s. 103-14
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Pericytes are smooth muscle-like cells found in close contact with the endothelium in capillaries, where they regulate the morphology and function of the vessels. During vessel formation, platelet-derived growth factor-BB (PDGF-BB) is required for the recruitment and differentiation of pericytes. Tumor vessels display abnormal morphology and increased endothelial proliferation, resulting in leaky, tortuous vessels that are often poorly perfused. These vessels typically display decreased pericyte density, and the tumor-associated pericytes often express abnormal markers and show abnormal morphology. Anti-angiogenic therapy targeting pro-angiogenic growth factor pathways has been applied to a broad range of solid tumors with varying results. Studies utilizing mouse models indicate that the presence of pericytes protect endothelial cells against inhibition of vascular endothelial growth factor (VEGF) signaling. Simultaneous inhibition of PDGF receptors on pericytes therefore improves the effect of VEGF inhibitors on endothelial cells and enhances anti-angiogenic therapy.
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| 36. |
- Hägerstrand, Daniel, et al.
(författare)
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Characterization of an imatinib-sensitive subset of high-grade human glioma cultures
- 2006
-
Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 25:35, s. 4913-4922
-
Tidskriftsartikel (refereegranskat)abstract
- High-grade gliomas, including glioblastomas, are malignant brain tumors for which improved treatment is urgently needed. Genetic studies have demonstrated the existence of biologically distinct subsets. Preliminary studies have indicated that platelet-derived growth factor (PDGF) receptor signaling contributes to the growth of some of these tumors. In this study, human high-grade glioma primary cultures were analysed for sensitivity to treatment with the PDGF receptor inhibitor imatinib/Glivec/Gleevec/STI571. Six out of 15 cultures displayed more than 40% growth inhibition after imatinib treatment, whereas seven cultures showed less than 20% growth inhibition. In the sensitive cultures, apoptosis contributed to growth inhibition. Platelet-derived growth factor receptor status correlated with imatinib sensitivity. Supervised analyses of gene expression profiles and real-time PCR analyses identified expression of the chemokine CXCL12/SDF-1 (stromal cell-derived factor 1) as a predictor of imatinib sensitivity. Exogenous addition of CXCL12 to imatinib-insensitive cultures conferred some imatinib sensitivity. Finally, coregulation of CXCL12 and PDGF alpha-receptor was observed in glioblastoma biopsies. We have thus defined the characteristics of a novel imatinib-sensitive subset of glioma cultures, and provided evidence for a functional relationship between imatinib sensitivity and chemokine signaling. These findings will assist in the design and evaluation of clinical trials exploring therapeutic effects of imatinib on malignant brain tumors.
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| 37. |
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| 38. |
- Kawasaki, Natsumi, et al.
(författare)
-
TUFT1 interacts with RABGAP1 and regulates mTORC1 signaling
- 2018
-
Ingår i: CELL DISCOVERY. - : NATURE PUBLISHING GROUP. - 2056-5968. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- The mammalian target of rapamycin (mTOR) pathway is commonly activated in human cancers. The activity of mTOR complex 1 (mTORC1) signaling is supported by the intracellular positioning of cellular compartments and vesicle trafficking, regulated by Rab GTPases. Here we showed that tuftelin 1 (TUFT1) was involved in the activation of mTORC1 through modulating the Rab GTPase-regulated process. TUFT1 promoted tumor growth and metastasis. Consistently, the expression of TUFT1 correlated with poor prognosis in lung, breast and gastric cancers. Mechanistically, TUFT1 physically interacted with RABGAP1, thereby modulating intracellular lysosomal positioning and vesicular trafficking, and promoted mTORC1 signaling. In addition, expression of TUFT1 predicted sensitivity to perifosine, an alkylphospholipid that alters the composition of lipid rafts. Perifosine treatment altered the positioning and trafficking of cellular compartments to inhibit mTORC1. Our observations indicate that TUFT1 is a key regulator of the mTORC1 pathway and suggest that it is a promising therapeutic target or a biomarker for tumor progression.
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| 39. |
- Kłosowska-Wardega, Agnieszka, et al.
(författare)
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Combination therapy using imatinib and vatalanib improves the therapeutic efficiency of paclitaxel towards a mouse melanoma tumor
- 2011
-
Ingår i: Melanoma research. - : Wolters Kluwer Health | Lippincott Williams & Wilkins. - 0960-8931 .- 1473-5636. ; 21:1, s. 57-65
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Tidskriftsartikel (refereegranskat)abstract
- Melanomas respond poorly to chemotherapy. In this study, we investigated the sensitization of B16 mouse melanoma tumors to paclitaxel by a combination of two tyrosine kinase inhibitors: vatalanib, targeting vascular endothelial growth factor receptors, and imatinib, an inhibitor targeting for example, Abl/BCR-ABL, the platelet-derived growth factor receptor, and stem cell factor receptor c-Kit. C57Bl6/J mice carrying B16/PDGF-BB mouse melanoma tumors were treated daily with vatalanib (25 mg/kg), imatinib (100 mg/kg), or a combination of these drugs. Paclitaxel was given subcutaneously twice during the study. The effects of the drugs on tumor cell proliferation in vitro were determined by counting cells. B16/PDGF-BB mouse melanoma tumors were not sensitive to paclitaxel at doses of either 5 or 20 mg/kg. However, the tumor growth was significantly reduced by 58%, in response to paclitaxel (5 mg/kg) when administered with daily doses of both vatalanib and imatinib. Paclitaxel only inhibited the in-vitro growth of B16/PDGF-BB tumor cells when given in combination with imatinib. Imatinib presumably targets c-Kit, as the cells do not express platelet-derived growth factor receptor and as another c-Abl inhibitor was without effect. This was supported by data from three c-Kit-expressing human melanoma cell lines showing varying sensitization to paclitaxel by the kinase inhibitors. In addition, small interfering RNA knockdown of c-Kit sensitized the cells to paclitaxel. These data show that combination of two tyrosine kinase inhibitors, imatinib and vatalanib, increases the effects of paclitaxel on B16/PDGF-BB tumors, thus suggesting a novel strategy for the treatment of melanomas expressing c-Kit.
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| 40. |
- Kłosowska-Wardega, Agnieszka, et al.
(författare)
-
Combined anti-angiogenic therapy targeting PDGF and VEGF receptors lowers the interstitial fluid pressure in a murine experimental carcinoma
- 2009
-
Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 4:12, s. e8149-
-
Tidskriftsartikel (refereegranskat)abstract
- Elevation of the interstitial fluid pressure (IFP) of carcinoma is an obstacle in treatment of tumors by chemotherapy and correlates with poor drug uptake. Previous studies have shown that treatment with inhibitors of platelet-derived growth factor (PDGF) or vascular endothelial growth factor (VEGF) signaling lowers the IFP of tumors and improve chemotherapy. In this study, we investigated whether the combination of PDGFR and VEGFR inhibitors could further reduce the IFP of KAT-4 human carcinoma tumors. The tumor IFP was measured using the wick-in-needle technique. The combination of STI571 and PTK/ZK gave an additive effect on the lowering of the IFP of KAT-4 tumors, but the timing of the treatment was crucial. The lowering of IFP following combination therapy was accompanied by vascular remodeling and decreased vascular leakiness. The effects of the inhibitors on the therapeutic efficiency of Taxol were investigated. Whereas the anti-PDGF and anti-VEGF treatment did not significantly inhibit tumor growth, the inhibitors enhanced the effect of chemotherapy. Despite having an additive effect in decreasing tumor IFP, the combination therapy did not further enhance the effect of chemotherapy. Simultaneous targeting of VEGFR and PDGFR kinase activity may be a useful strategy to decrease tumor IFP, but the timing of the inhibitors should be carefully determined.
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| 41. |
- Kowanetz, Marcin, et al.
(författare)
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TGFβ induces SIK to negatively regulate type I receptor kinase signaling
- 2008
-
Ingår i: Journal of Cell Biology. - : The Rockefeller University Press. - 0021-9525 .- 1540-8140. ; 182:4, s. 655-662
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Tidskriftsartikel (refereegranskat)abstract
- Signal transduction by transforming growth factor beta (TGFbeta) coordinates physiological responses in diverse cell types. TGFbeta signals via type I and type II receptor serine/threonine kinases and intracellular Smad proteins that regulate transcription. Strength and duration of TGFbeta signaling is largely dependent on a negative-feedback program initiated during signal progression. We have identified an inducible gene target of TGFbeta/Smad signaling, the salt-inducible kinase (SIK), which negatively regulates signaling together with Smad7. SIK and Smad7 form a complex and cooperate to down-regulate the activated type I receptor ALK5. We further show that both the kinase and ubiquitin-associated domain of SIK are required for proper ALK5 degradation, with ubiquitin functioning to enhance SIK-mediated receptor degradation. Loss of endogenous SIK results in enhanced gene responses of the fibrotic and cytostatic programs of TGFbeta. We thus identify in SIK a negative regulator that controls TGFbeta receptor turnover and physiological signaling.
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| 42. |
- Lönn, Peter, et al.
(författare)
-
PARP-1 attenuates Smad-mediated transcription
- 2010
-
Ingår i: Molecular Cell. - : Elsevier BV. - 1097-2765 .- 1097-4164. ; 40:4, s. 521-532
-
Tidskriftsartikel (refereegranskat)abstract
- The versatile cytokine transforming growth factor β (TGF-β) regulates cellular growth, differentiation, and migration during embryonic development and adult tissue homeostasis. Activation of TGF-β receptors leads to phosphorylation of Smad2 and Smad3, which oligomerize with Smad4 and accumulate in the nucleus where they recognize gene regulatory regions and orchestrate transcription. Termination of Smad-activated transcription involves Smad dephosphorylation, nuclear export, or ubiquitin-mediated degradation. In an unbiased proteomic screen, we identified poly(ADP-ribose) polymerase-1 (PARP-1) as a Smad-interacting partner. PARP-1 dissociates Smad complexes from DNA by ADP-ribosylating Smad3 and Smad4, which attenuates Smad-specific gene responses and TGF-β-induced epithelial-mesenchymal transition. Thus, our results identify ADP-ribosylation of Smad proteins by PARP-1 as a key step in controlling the strength and duration of Smad-mediated transcription.
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| 43. |
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| 44. |
- Lönn, Peter, et al.
(författare)
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Transcriptional induction of salt-inducible kinase 1 by transforming growth factor β leads to negative regulation of type I receptor signaling in cooperation with the Smurf2 ubiquitin ligase
- 2012
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 287:16, s. 12867-12878
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Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor β (TGFβ)1 regulates many physiological processes and requires control mechanisms to safeguard proper and timely action. We have previously described how negative regulation of TGFβ signaling is controlled by the serine/threonine kinase salt-inducible kinase (SIK) 1. SIK1 forms complexes with the TGFβ type I receptor and with the inhibitory Smad7 and downregulates the type I receptor. We now demonstrate that TGFβ induces SIK1 levels via a direct transcriptional mechanism that implicates the Smad proteins and we have mapped a putative enhancer element on the SIK1 gene. We provide evidence that the ubiquitin ligase Smurf2 forms complexes and functionally cooperates with SIK1. Both the kinase activity of SIK1 and the ubiquitin ligase activity of Smurf2 are important for proper type I receptor turnover. We also show that knockdown of endogenous SIK1 and Smurf2 enhances physiological signaling by TGFβ that leads to epithelial growth arrest. In conclusion, TGFβ induces expression of Smad7, Smurf2 and SIK1, the products of which physically and functionally interlink to control the activity of this pathway.
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| 45. |
- Maturi, Varun, et al.
(författare)
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Genome-wide binding of transcription factor ZEB1 in triple-negative breast cancer cells
- 2018
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 233:10, s. 7113-7127
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Tidskriftsartikel (refereegranskat)abstract
- Zinc finger E-box binding homeobox 1 (ZEB1) is a transcriptional regulator involved in embryonic development and cancer progression. ZEB1 induces epithelial-mesenchymal transition (EMT). Triple-negative human breast cancers express high ZEB1 mRNA levels and exhibit features of EMT. In the human triple-negative breast cancer cell model Hs578T, ZEB1 associates with almost 2,000 genes, representing many cellular functions, including cell polarity regulation (DLG2 and FAT3). By introducing a CRISPR-Cas9-mediated 30bp deletion into the ZEB1 second exon, we observed reduced migratory and anchorage-independent growth capacity of these tumor cells. Transcriptomic analysis of control and ZEB1 knockout cells, revealed 1,372 differentially expressed genes. The TIMP metallopeptidase inhibitor 3 and the teneurin transmembrane protein 2 genes showed increased expression upon loss of ZEB1, possibly mediating pro-tumorigenic actions of ZEB1. This work provides a resource for regulators of cancer progression that function under the transcriptional control of ZEB1. The data confirm that removing a single EMT transcription factor, such as ZEB1, is not sufficient for reverting the triple-negative mesenchymal breast cancer cells into more differentiated, epithelial-like clones, but can reduce tumorigenic potential, suggesting that not all pro-tumorigenic actions of ZEB1 are linked to the EMT.
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| 46. |
- Maturi, Varun, et al.
(författare)
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Genomewide binding of transcription factor Snail1 in triple-negative breast cancer cells
- 2018
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Ingår i: Molecular Oncology. - : WILEY. - 1574-7891 .- 1878-0261. ; 12:7, s. 1153-1174
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Tidskriftsartikel (refereegranskat)abstract
- Transcriptional regulation mediated by the zinc finger protein Snail1 controls early embryogenesis. By binding to the epithelial tumor suppressor CDH1 gene, Snail1 initiates the epithelial-mesenchymal transition (EMT). The EMT generates stem-like cells and promotes invasiveness during cancer progression. Accordingly, Snail1 mRNA and protein is abundantly expressed in triple-negative breast cancers with enhanced metastatic potential and phenotypic signs of the EMT. Such high endogenous Snail1 protein levels permit quantitative chromatin immunoprecipitation-sequencing (ChIP-seq) analysis. Snail1 associated with 185 genes at cis regulatory regions in the Hs578T triple-negative breast cancer cell model. These genes include morphogenetic regulators and signaling components that control polarized differentiation. Using the CRISPR/Cas9 system in Hs578T cells, a double deletion of 10bp each was engineered into the first exon and into the second exon-intron junction of Snail1, suppressing Snail1 expression and causing misregulation of several hundred genes. Specific attention to regulators of chromatin organization provides a possible link to new phenotypes uncovered by the Snail1 loss-of-function mutation. On the other hand, genetic inactivation of Snail1 was not sufficient to establish a full epithelial transition to these tumor cells. Thus, Snail1 contributes to the malignant phenotype of breast cancer cells via diverse new mechanisms.
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| 47. |
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| 48. |
- Morén, Anita, et al.
(författare)
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LXR alpha limits TGF beta-dependent hepatocellular carcinoma associated fibroblast differentiation
- 2019
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Ingår i: Oncogenesis. - : Springer Science and Business Media LLC. - 2157-9024. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor beta (TGF beta) is deposited in the extracellular space of diverse tissues. Resident fibroblasts respond to TGF beta and undergo myofibroblastic differentiation during tissue wound healing and cancer progression. Cancer-associated fibroblasts (CAFs) communicate with tumor cells during cancer progression, under the guidance of TGF beta signaling. We report that agonist-activated liver X receptors (LXR) limit the expression of key components of myofibroblast differentiation, including the a-smooth muscle actin (alpha SMA) gene in liver cancer cells. CAFs derived from hepatocellular carcinoma (HCC) express high aSMA and low LXR alpha levels, whereas hepatocarcinoma cells exhibit an inverse expression pattern. All hepatoma cells analyzed responded to the LXR alpha agonist T0901317 by inducing fatty acid synthase (FASN) expression. On the other hand, T0901317 antagonized TGF beta-induced fibroblastic marker responses, such as fibronectin and calponin, in a subset of hepatoma cells and all CAFs analyzed. Mechanistically, LXR alpha antagonized TGF beta signaling at the transcriptional level. Smad3 and LXR alpha were recruited to adjacent DNA motifs of the ACTA2 promoter. Upon cloning the human ACTA2 promoter, we confirmed its transcriptional induction by TGF beta stimulation, and LXR alpha overexpression repressed the promoter activity. Hepatosphere formation by HCC cells was enhanced upon co-culturing with CAFs. T0901317 suppressed the positive effects exerted on hepatosphere growth by CAFs. Taken together, the data suggest that LXR alpha agonists limit TGF beta-dependent CAF differentiation, potentially limiting primary HCC growth.
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| 49. |
- Morén, Anita, et al.
(författare)
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Negative regulation of TGFβ signaling by the kinase LKB1 and the scaffolding protein LIP1
- 2011
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Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 286:1, s. 341-353
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Tidskriftsartikel (refereegranskat)abstract
- Signal transduction by the Smad pathway elicits critical biological responses to many extracellular polypeptide factors, including TGFβ and bone morphogenetic protein. Regulation of Smad signaling imparts several cytoplasmic and nuclear mechanisms, some of which entail protein phosphorylation. Previous work established a protein complex between Smad4 and the scaffolding protein LKB1-interacting protein 1 (LIP1). LKB1 is a well studied tumor suppressor kinase that regulates cell growth and polarity. Here, we analyzed the LKB1-LIP1 and the Smad4-LIP1 protein complexes and found that LIP1 can self-oligomerize. We further demonstrate that LKB1 is capable of phosphorylating Smad4 on Thr(77) of its DNA-binding domain. LKB1 inhibits Smad4 from binding to either TGFβ- or bone morphogenetic protein-specific promoter sequences, which correlates with the negative regulatory effect LKB1 exerts on Smad4-dependent transcription. Accordingly, LKB1 negatively regulates TGFβ gene responses and epithelial-mesenchymal transition. Thus, LKB1 and LIP1 provide negative control of TGFβ signaling.
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| 50. |
- 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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