| 1. |
- Blumel, Edda, et al.
(författare)
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Staphylococcal alpha-toxin tilts the balance between malignant and non-malignant CD4+ T cells in cutaneous T-cell lymphoma
- 2019
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Ingår i: Oncoimmunology. - : Taylor & Francis. - 2162-4011 .- 2162-402X. ; 8:11
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus is implicated in disease progression in cutaneous T-cell lymphoma (CTCL). Here, we demonstrate that malignant T cell lines derived from CTCL patients as well as primary malignant CD4+ T cells from Sézary syndrome patients are considerably more resistant to alpha-toxin-induced cell death than their non-malignant counterparts. Thus, in a subset of Sézary syndrome patients the ratio between malignant and non-malignant CD4+ T cells increases significantly following exposure to alpha-toxin. Whereas toxin-induced cell death is ADAM10 dependent in healthy CD4+ T cells, resistance to alpha-toxin in malignant T cells involves both downregulation of ADAM10 as well as other resistance mechanisms. In conclusion, we provide first evidence that Staphylococcus aureus derived alpha-toxin can tilt the balance between malignant and non-malignant CD4+ T cells in CTCL patients. Consequently, alpha-toxin may promote disease progression through positive selection of malignant CD4+ T cells, identifying alpha-toxin as a putative drug target in CTCL.
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| 2. |
- Buus, Terkild Brink, et al.
(författare)
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Single-cell heterogeneity in Sézary syndrome
- 2018
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Ingår i: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 2:16, s. 2115-2126
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Tidskriftsartikel (refereegranskat)abstract
- Sezary syndrome (SS) is an aggressive leukemic variant of cutaneous T-cell lymphoma (CTCL) with a median life expectancy of less than 4 years. Although initial treatment responses are often good, the vast majority of patients with SS fail to respond to ongoing therapy. We hypothesize that malignant T cells are highly heterogeneous and harbor subpopulations of SS cells that are both sensitive and resistant to treatment. Here, we investigate the presence of single-cell heterogeneity and resistance to histone deacetylase inhibitors (HDACi) within primary malignant T cells from patients with SS. Using single-cell RNA sequencing and flow cytometry, we find that malignant T cells from all investigated patients with SS display a high degree of single-cell heterogeneity at both the mRNA and protein levels. We show that this heterogeneity divides the malignant cells into distinct subpopulations that can be isolated by their expression of different surface antigens. Finally, we show that treatment with HDACi (suberanilohydroxamic acid and romidepsin) selectively eliminates some subpopulations while leaving other subpopulations largely unaffected. In conclusion, we show that patients with SS display a high degree of single-cell heterogeneity within the malignant T-cell population, and that distinct subpopulations of malignant T cells carry HDACi resistance. Our data point to the importance of understanding the heterogeneous nature of malignant SS cells in each individual patient to design combinational and new therapies to counter drug resistance and treatment failure.
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| 3. |
- Fredholm, Simon, et al.
(författare)
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SATB1 in Malignant T Cells
- 2018
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Ingår i: Journal of Investigative Dermatology. - : Elsevier. - 0022-202X .- 1523-1747. ; 138:8, s. 1805-1815
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Tidskriftsartikel (refereegranskat)abstract
- Deficient expression of SATB1 hampers thymocyte development and results in inept T-cell lineages. Recent data implicate dysregulated SATB1 expression in the pathogenesis of mycosis fungoides, the most frequent variant of cutaneous T-cell lymphoma. Here, we report on a disease stage-associated decrease of SATB1 expression and an inverse expression of STAT5 and SATB1 in situ. STAT5 inhibited SATB1 expression through induction of microRNA-155. Decreased SATB1 expression triggered enhanced expression of IL-5 and IL-9 (but not IL-6 and IL-32), whereas increased SATB1 expression had the opposite effect, indicating that the microRNA-155 target SATB1 is a repressor of IL-5 and IL-9 in malignant T cells. In accordance, inhibition of STAT5 and its upstream activator JAK3 triggered increased SATB1 expression and a concomitant suppression of IL-5 and IL-9 expression in malignant T cells. In conclusion, we provide a mechanistic link between the proto-oncogenic JAK3/STAT5/microRNA-155 pathway, SATB1, and cytokines linked to CTCL severity and progression, indicating that SATB1 dysregulation is involved in cutaneous T-cell lymphoma pathogenesis.
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| 4. |
- Gluud, Maria, et al.
(författare)
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MicroRNAs in the Pathogenesis, Diagnosis, Prognosis and Targeted Treatment of Cutaneous T-Cell Lymphomas
- 2020
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 12:5
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Forskningsöversikt (refereegranskat)abstract
- Cutaneous T-cell lymphoma (CTCL) represents a heterogeneous group of potentially devastating primary skin malignancies. Despite decades of intense research efforts, the pathogenesis is still not fully understood. In the early stages, both clinical and histopathological diagnosis is often difficult due to the ability of CTCL to masquerade as benign skin inflammatory dermatoses. Due to a lack of reliable biomarkers, it is also difficult to predict which patients will respond to therapy or progress towards severe recalcitrant disease. In this review, we discuss recent discoveries concerning dysregulated microRNA (miR) expression and putative pathological roles of oncogenic and tumor suppressive miRs in CTCL. We also focus on the interplay between miRs, histone deacetylase inhibitors, and oncogenic signaling pathways in malignant T cells as well as the impact of miRs in shaping the inflammatory tumor microenvironment. We highlight the potential use of miRs as diagnostic and prognostic markers, as well as their potential as therapeutic targets. Finally, we propose that the combined use of miR-modulating compounds with epigenetic drugs may provide a novel avenue for boosting the clinical efficacy of existing anti-cancer therapies in CTCL.
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| 5. |
- Krishna Vadivel, Chella, et al.
(författare)
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Staphylococcus aureus induce drug resistance in cancer T cells in Sézary Syndrome
- 2024
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Ingår i: Blood. - 0006-4971 .- 1528-0020. ; 143:15, s. 1496-1512
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Tidskriftsartikel (refereegranskat)abstract
- Key Points Enterotoxins from Staphylococcus aureus bacteria induce drug resistance in primary malignant T cells in Sézary syndrome. Targeting bacteria, their toxins, and downstream signaling pathways in malignant T cells abrogate the induction of drug resistance. Patients with Sézary syndrome (SS), a leukemic variant of cutaneous T cell lymphoma (CTCL), are prone to Staphylococcus aureus (S. aureus) infections and have a poor prognosis due to treatment-resistance. Here, we report that S. aureus and staphylococcal enterotoxins (SE) induce drug resistance in malignant T-cells against therapeutics commonly used in CTCL. Supernatant from patient-derived, SE-producing S. aureus and recombinant SE significantly inhibit cell death induced by HDAC inhibitor romidepsin in primary malignant T-cells from SS patients. Bacterial killing by engineered, bacteriophage-derived, S. aureus-specific endolysin (XZ.700) abrogates the effect of S. aureus supernatant. Likewise, mutations in MHC Class II binding sites of SE type-A (SEA) and anti-SEA antibody block induction of resistance. Importantly, SE also triggers resistance to other HDAC inhibitors (vorinostat and resminostat) and chemotherapeutic drugs (doxorubicin and etoposide). Multimodal single-cell sequencing indicates TCR, NFB, and JAK/STAT signaling pathways (previously associated with drug-resistance) as putative mediators of SE-induced drug resistance. In support, inhibition of TCR-signaling and Protein Kinase C (upstream of NFB) counteracts SE-induced rescue from drug-induced cell death. Inversely, SE cannot rescue from cell death induced by proteasome/NFB inhibitor bortezomib. Inhibition of JAK/STAT only blocks SE-induced rescue of malignant T-cells in some but not all patients, suggesting two distinct ways SE can induce drug resistance. In conclusion, we show that S. aureus enterotoxins induce drug-resistance in primary malignant T-cells. These findings suggest that S. aureus enterotoxins cause clinical treatment-resistance in SS patients and that anti-bacterial measures may improve the outcome of cancer-directed therapy in patients harboring S. aureus
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| 6. |
- Lindahl, Lise M., et al.
(författare)
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STAT5 induces miR-21 expression in cutaneous T cell lymphoma
- 2016
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:29, s. 45730-45744
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Tidskriftsartikel (refereegranskat)abstract
- In cutaneous T cell lymphomas (CTCL), miR-21 is aberrantly expressed in skin and peripheral blood and displays anti-apoptotic properties in malignant T cells. It is, however, unclear exactly which cells express miR-21 and what mechanisms regulate miR-21. Here, we demonstrate miR-21 expression in situ in both malignant and reactive lymphocytes as well as stromal cells. qRT-PCR analysis of 47 patients with mycosis fungoides (MF) and Sezary Syndrome (SS) confirmed an increased miR- 21 expression that correlated with progressive disease. In cultured malignant T cells miR-21 expression was inhibited by Tofacitinib (CP-690550), a clinical-grade JAK3 inhibitor. Chromatin immunoprecipitation (ChIP) analysis showed direct binding of STAT5 to the miR-21 promoter. Cytokine starvation ex vivo triggered a decrease in miR-21 expression, whereas IL-2 induced an increased miR-21 expression in primary SS T cells and cultured cytokine-dependent SS cells (SeAx). siRNA-mediated depletion of STAT5 inhibited constitutive- and IL-2- induced miR-21 expression in cytokine- independent and dependent T cell lines, respectively. IL-15 and IL-2 were more potent than IL-21 in inducing miR-21 expression in the cytokine-dependent T cells. In conclusion, we provide first evidence that miR-21 is expressed in situ in CTCL skin lesions, induced by IL-2 and IL-15 cytokines, and is regulated by STAT5 in malignant T cells. Thus, our data provide novel evidence for a pathological role of IL-2Rg cytokines in promoting expression of the oncogenic miR-21 in CTCL.
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| 7. |
- Metzler, Veronika M., et al.
(författare)
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Androgen dependent mechanisms of pro-angiogenic networks in placental and tumor development
- 2017
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Ingår i: Placenta. - : W B SAUNDERS CO LTD. - 0143-4004 .- 1532-3102. ; 56, s. 79-85
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Tidskriftsartikel (refereegranskat)abstract
- The placenta and tumors share important characteristics, including a requirement to establish effective angiogenesis. In the case of the placenta, optimal angiogenesis is required to sustain the blood flow required to maintain a successful pregnancy, whereas in tumors establishing new blood supplies is considered a key step in supporting metastases. Therefore the development of novel angiogenesis inhibitors has been an area of active research in oncology. A subset of the molecular processes regulating angiogenesis are well understood in the context of both early placentation and tumorigenesis. In this review we focus on the well-established role of androgen regulation of angiogenesis in cancer and relate these mechanisms to placental angiogenesis. The physiological actions of androgens are mediated by the androgen receptor (AR), a ligand dependent transcription factor. Androgens and the AR are essential for normal male embryonic development, puberty and lifelong health. Defects in androgen signalling are associated with a diverse range of clinical disorders in men and women including disorders of sex development (DSD), polycystic ovary syndrome in women and many cancers. We summarize the diverse molecular mechanisms of androgen regulation of angiogenesis and infer the potential significance of these pathways to normal and pathogenic placental function. Finally, we offer potential research applications of androgen-targeting molecules developed to treat cancer as investigative tools to help further delineate the role of androgen signalling in placental function and maternal and offspring health in animal models.
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| 8. |
- Sarwar, Martuza, et al.
(författare)
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The role of PIP5K1 alpha/pAKT and targeted inhibition of growth of subtypes of breast cancer using PIP5K1 alpha inhibitor
- 2019
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Ingår i: Oncogene. - : Nature Publishing Group. - 0950-9232 .- 1476-5594. ; 38:3, s. 375-389
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Tidskriftsartikel (refereegranskat)abstract
- Despite recent improvement in adjuvant therapies, triple-negative, and ER+ subtypes of breast cancer (BC) with metastatic potentials remain the leading cause of BC-related deaths. We investigated the role of phosphatidylinositol-4-phosphate 5-kinase alpha (PIP5Kα), a key upstream factor of PI3K/AKT, and the therapeutic effect of PIP5Kα inhibitor on subtypes of BC. The clinical importance of PIP5K1α and its association with survivals were analyzed using three BC cohorts from Nottingham (n = 913), KM plotter (n = 112) and TCGA (n = 817). Targeted overexpression or knockdown of PIP5K1α were introduced into BC cell lines. The effects of PIP5K1α and its inhibitor on growth and invasion of BC were confirmed by using in vitro assays including proliferation, migration, apoptosis and luciferase reporter assays and in vivo xenograft mouse models. All statistical tests were two-sided. PIP5K1α was associated with poor patient outcome in triple-negative BC (for PIP5K1α protein, p = 0.011 and for mRNA expression, p = 0.028, log-rank test). 29% of triple-negative BC had PIP5K1A gene amplification. Elevated level of PIP5K1α increased expression of pSer-473 AKT (p < 0.001) and invasiveness of triple-negative MDA-MB-231 cells (p < 0.001). Conversely, inhibition of PIP5K1α using its inhibitor ISA-2011B, or via knockdown suppressed growth and invasiveness of MDA-MB-231 xenografts (mean vehicle-treated controls = 2160 mm3, and mean ISA-2011B-treated = 600 mm3, p < 0.001). ISA-2011B-treatment reduced expression of pSer-473 AKT (p < 0.001) and its downstream effectors including cyclin D1, VEGF and its receptors, VEGFR1 and VEGFR2 (p < 0.001) in xenograft tumors. In ER+ cancer cells, PIP5K1α acted on pSer-473 AKT, and was in complexes with VEGFR2, serving as co-factor of ER-alpha to regulate activities of target genes including cyclin D1 and CDK1. Our study suggests that our developed PIP5K1α inhibitor has a great potential on refining targeted therapeutics for treatment of triple-negative and ER+ BC with abnormal PI3K/AKT pathways.
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| 9. |
- Vadivel, Chella Krishna, et al.
(författare)
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JAK3 Is Expressed in the Nucleus of Malignant T Cells in Cutaneous T Cell Lymphoma (CTCL).
- 2021
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 13:2
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Tidskriftsartikel (refereegranskat)abstract
- Perturbation in JAK-STAT signaling has been reported in the pathogenesis of cutaneous T cell lymphoma (CTCL). JAK3 is predominantly associated with the intra-cytoplasmic part of IL-2Rγc located in the plasma membrane of hematopoietic cells. Here we demonstrate that JAK3 is also ectopically expressed in the nucleus of malignant T cells. We detected nuclear JAK3 in various CTCL cell lines and primary malignant T cells from patients with Sézary syndrome, a leukemic variant of CTCL. Nuclear localization of JAK3 was independent of its kinase activity whereas STAT3 had a modest effect on nuclear JAK3 expression. Moreover, JAK3 nuclear localization was only weakly affected by blockage of nuclear export. An inhibitor of the nuclear export protein CRM1, Leptomycin B, induced an increased expression of SOCS3 in the nucleus, but only a weak increase in nuclear JAK3. Importantly, immunoprecipitation experiments indicated that JAK3 interacts with the nuclear protein POLR2A, the catalytic subunit of RNA Polymerase II. Kinase assays showed tyrosine phosphorylation of recombinant human Histone H3 by JAK3 in vitro-an effect which was blocked by the JAK inhibitor (Tofacitinib citrate). In conclusion, we provide the first evidence of nuclear localization of JAK3 in malignant T cells. Our findings suggest that JAK3 may have a cytokine-receptor independent function in the nucleus of malignant T cells, and thus a novel non-canonical role in CTCL.
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