ARF is a small, highly basic protein that can be induced by oncogenic stimuli and exerts growth-inhibitory and tumour-suppressive activities through the activation of p53. Here we show that, in human ...melanocytes, ARF is cytoplasmic, constitutively expressed, and required for maintaining low steady-state levels of superoxide under conditions of mitochondrial dysfunction. This mitochondrial activity of ARF is independent of its known autophagic and p53-dependent functions, and involves the evolutionarily conserved acidic motif GHDDGQ, which exhibits weak homology to BCL-2 homology 3 (BH3) domains and mediates interaction with BCL-xL--an important regulator of mitochondrial redox homeostasis. Melanoma-predisposing CDKN2A germline mutations, which affect conserved glycine and aspartate residues within the GHDDGQ motif, impair the ability of ARF to control superoxide production and suppress growth of melanoma cells in vivo. These results reveal an important cell-protective function of ARF that links mitochondrial dysfunction and susceptibility to melanoma.
Cutaneous T-cell lymphomas (CTCLs) are the most frequent primary skin lymphomas. Nevertheless, diagnosis of early disease has proven difficult because of a clinical and histologic resemblance to ...benign inflammatory skin diseases. To address whether microRNA (miRNA) profiling can discriminate CTCL from benign inflammation, we studied miRNA expression levels in 198 patients with CTCL, peripheral T-cell lymphoma (PTL), and benign skin diseases (psoriasis and dermatitis). Using microarrays, we show that the most induced (miR-326, miR-663b, and miR-711) and repressed (miR-203 and miR-205) miRNAs distinguish CTCL from benign skin diseases with > 90% accuracy in a training set of 90 samples and a test set of 58 blinded samples. These miRNAs also distinguish malignant and benign lesions in an independent set of 50 patients with PTL and skin inflammation and in experimental human xenograft mouse models of psoriasis and CTCL. Quantitative (q)RT-PCR analysis of 103 patients with CTCL and benign skin disorders validates differential expression of 4 of the 5 miRNAs and confirms previous reports on miR-155 in CTCL. A qRT-PCR–based classifier consisting of miR-155, miR-203, and miR-205 distinguishes CTCL from benign disorders with high specificity and sensitivity, and with a classification accuracy of 95%, indicating that miRNAs have a high diagnostic potential in CTCL.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The pathogenesis of cutaneous T-cell lymphoma (CTCL) remains elusive. Recent discoveries indicate that the oncogenic microRNA miR-155 is overexpressed in affected skin from CTCL patients. Here, we ...address what drives the expression of miR-155 and investigate its role in the pathogenesis of CTCL. We show that malignant T cells constitutively express high levels of miR-155 and its host gene BIC (B cell integration cluster). Using ChIP-seq, we identify BIC as a target of transcription factor STAT5, which is aberrantly activated in malignant T cells and induced by IL-2/IL-15 in non-malignant T cells. Incubation with JAK inhibitor or siRNA-mediated knockdown of STAT5 decreases BIC/miR-155 expression, whereas IL-2 and IL-15 increase their expression in cell lines and primary cells. In contrast, knockdown of STAT3 has no effect, and BIC is not a transcriptional target of STAT3, indicating that regulation of BIC/miR-155 expression by STAT5 is highly specific. Malignant proliferation is significantly inhibited by an antisense-miR-155 as well as by knockdown of STAT5 and BIC.
In conclusion, we provide the first evidence that STAT5 drives expression of oncogenic BIC/miR-155 in cancer. Moreover, our data indicate that the STAT5/BIC/miR-155 pathway promotes proliferation of malignant T cells, and therefore is a putative target for therapy in CTCL.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
IL-17 is a proinflammatory cytokine that is crucial for the host's protection against a range of extracellular pathogens. However, inappropriately regulated expression of IL-17 is associated with the ...development of inflammatory diseases and cancer. In cutaneous T-cell lymphoma (CTCL), malignant T cells gradually accumulate in skin lesions characterized by massive chronic inflammation, suggesting that IL-17 could be involved in the pathogenesis. In this study we show that IL-17 protein is present in 10 of 13 examined skin lesions but not in sera from 28 CTCL patients. Importantly, IL-17 expression is primarily observed in atypical lymphocytes with characteristic neoplastic cell morphology. In accordance, malignant T-cell lines from CTCL patients produce IL-17 and the synthesis is selectively increased by IL-2 receptor β chain cytokines. Small-molecule inhibitors or small interfering RNA against Jak3 and signal transducer and activator of transcription 3 (Stat3) reduce the production of IL-17, showing that the Jak3/Stat3 pathway promotes the expression of the cytokine. In summary, our findings indicate that the malignant T cells in CTCL lesions express IL-17 and that this expression is promoted by the Jak3/Stat3 pathway.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Mycosis fungoides (MF) is the most common variant of cutaneous T-cell lymphoma (CTCL). MF is characterized by chronic inflammation dominated by cluster of differentiation 4-positive (CD4(+)) T-cells ...and T helper 2 cytokines, and as the malignant T-cell clone is initially elusive, early diagnosis is often impossible. MF usually takes an indolent course, but for unknown reasons may turn into an aggressive disease with a poor prognosis. Herein, we used a global quantitative real-time polymerase chain reaction platform to study microRNA (miR) expression in patients with early MF (n=13), more advanced CTCL (n=42), and atopic dermatitis (AD, n=20). Thirty-eight miRs were differentially expressed (≥2-fold) in early MF vs. AD and 36 in early MF vs. more advanced disease. miRs that distinguish early MF from AD included both up-regulated (miR-155, miR-146a, 146b-5p, miR-342-3p, let-7i*) and down-regulated (miR-203, miR-205) miRs previously implicated in advanced CTCL. When comparing early MF to more advanced CTCL, additional miRs were significantly up-regulated including miRs which are part of the oncogenic miR-17/92, 106b/25 and 106a/363 clusters. In 16 patients for whom detailed follow-up data were available, 72 miRs were found differentially expressed between patients with progressive vs. those with non-progressive disease, again including miRs with a known relevance for lymphomagenesis, e.g. miR-155, miR-21, let-7i, miR-16, miR-142-3p, miR-146b-5p, miR-92a, miR-93 and miR-106a. In conclusion, we showed that early MF and AD display very different miR profiles despite their clinical, histological, and immunological similarities. During progression, an additional set of miRs becomes deregulated, suggesting their role in disease progression. These data suggest that miR profiling in CTCL may be a key to improving both diagnosis and risk prediction.
Recent studies show that mantle cell lymphoma (MCL) express aberrant microRNA (miRNA) profiles; however, the clinical effect of miRNA expression has not previously been examined and validated in ...large prospective homogenously treated cohorts. We performed genome-wide miRNA microarray profiling of 74 diagnostic MCL samples from the Nordic MCL2 trial (screening cohort). Prognostic miRNAs were validated in diagnostic MCL samples from 94 patients of the independent Nordic MCL3 trial (validation cohort). Three miRNAs (miR-18b, miR-92a, and miR-378d) were significantly differentially expressed in patients who died of MCL in both cohorts. MiR-18b was superior to miR-92a and miR-378d in predicting high risk. Thus, we generated a new biological MCL International Prognostic Index (MIPI-B)-miR prognosticator, combining expression levels of miR-18b with MIPI-B data. Compared to the MIPI-B, this prognosticator improved identification of high-risk patients with regard to cause-specific, overall, and progression-free survival. Transfection of 2 MCL cell lines with miR-18b decreased their proliferation rate without inducing apoptosis, suggesting that miR-18b may render MCL cells resistant to chemotherapy by decelerating cell proliferation. We conclude that overexpression of miR-18b identifies patients with poor prognosis in 2 large prospective MCL cohorts and adds prognostic information to the MIPI-B. MiR-18b may reduce the proliferation rate of MCL cells as a mechanism of chemoresistance.
•miR-18b overexpression identified patients with poor prognosis in 2 large prospective homogenously treated MCL cohorts.•miR-18b overexpression adds prognostic information to the MIPI-B prognosticator.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
OBJECTIVE:Inflammation may contribute to an increased risk of cardiovascular disease (CVD) in HIV-1 infection. MicroRNAs (miRNAs) are involved in the regulation of inflammation. In treated ...HIV-1–infected individuals, we aimed to identify differentially expressed miRNAs with known roles in inflammation and CVD risk and to investigate associations between these and systemic inflammation.
METHODS:In a screening cohort including 14 HIV-1–infected individuals and 9 uninfected controls, microarray profiling was performed using peripheral blood mononuclear cells (PBMCs). Differentially regulated miRNAs previously related to inflammation and CVD were validated using real-time quantitative reverse-transcription polymerase chain reaction in 26 HIV-1–infected individuals and 20 uninfected controls. Validated miRNAs were measured in PBMCs, CD4 and CD8 T cells. Interleukin-6, tumor necrosis factor-alpha, high-sensitivity C-reactive protein, lipopolysaccharide (LPS), cytomegalovirus immunoglobulin G, lipids, and fasting glucose were measured, and associations with validated miRNAs were assessed with multiple linear regression analysis.
RESULTS:Upregulation of miR-210, miR-7, and miR-331 was found in PBMCs from HIV-1–infected individuals when compared with those from uninfected controls (P < 0.005). In contrast, miR-210 and miR-331 were downregulated in CD8 T cells. In multivariate analysis, miR-210 in CD8 T cells was negatively associated with LPS (P = 0.023) and triglycerides (P = 0.003) but positively associated with tumor necrosis factor-alpha (P = 0.004). MiR-7 in PBMC was positively associated with interleukin-6 (P = 0.025) and fasting glucose (P = 0.005), whereas miR-331 was negatively associated with LPS (P = 0.006). In PBMCs from HIV-1–infected individuals with low cytomegalovirus immunoglobulin G, miR-7, miR-29a, miR-221, and miR-222 were downregulated.
CONCLUSION:In 2 independent cohorts, miR-210, miR-7, and miR-331 were differentially regulated in treated HIV-1–infected individuals and associated with markers of systemic inflammation.
Recently, miR‐155 has been implicated in cutaneous T‐cell lymphoma (CTCL). Thus, elevated levels of miR‐155 were observed in skin lesions from CTCL patients as judged from qPCR and micro‐array ...analysis and aberrant, high miR‐155 expression was associated with severe disease. Moreover, miR‐155 promoted proliferation of malignant T cells in vitro. Little is, however, known about which cell types express miR‐155 in vivo in CTCL skin lesions. Here, we study miR‐155 expression using in situ hybridization (ISH) with a miR‐155 probe, a negative control (scrambled), and a miR‐126 probe as a positive control in nine patients with mycosis fungoides, the most frequent subtype of CTCL. We provide evidence that both malignant and non‐malignant T cells stain weakly to moderately positive with the miR‐155 probe, but generally negative with the miR‐126 and negative control probes. Reversely, endothelial cells stain positive for miR‐126 and negative for miR‐155 and the control probe. Solitary T cells with a malignant morphology display brighter staining with the miR‐155 probe. Taken together, our findings suggest that both malignant and non‐malignant T cells express miR‐155 in situ in CTCL. Moreover, they indicate heterogeneity in miR‐155 expression among malignant T cells.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Background Mantle cell lymphoma (MCL) is a subtype of non-Hodgkin‘s lymphoma (NHL) with a variable but often aggressive clinical course. The majority of MCL patients ≤65 years will experience ...clinical relapse during a 10-year period (Geisler et al. Br J Haematol 2012). Risk-stratification is therefore of great importance in order to identify patients who are eligible for novel or alternative treatment regimens. Minimal residual disease (MRD) monitoring can predict clinical progression in MCL and guide pre-emptive treatment with rituximab as single agent. It has thus far not been possible to predict post-treatment molecular relapse (MRD-positivity). Although some recent studies have shown that aberrant miRNA expression delineate pathogenic molecular pathways and predict survival in MCL patients, miRNA profiling has not been performed in the context of MRD and molecular relapse.
Aims We assessed MCL miRNA expression, in a large, prospective, uniformly treated patient cohort followed with molecular markers for MRD to determine if miRNAs could predict molecular relapse.
Methods Diagnostic MCL tumor samples from 114 patients in the Nordic MCL2 and MCL3 clinical trials were retrieved. All patients had confirmed CyclinD1 overexpression and 96 patients had Ki-67 expression measurement for use in the MIPI-B predictive score. All patients received almost identical induction treatment with six alternating cycles of maxi-CHOP and high-dose Ara-C in combination with rituximab. Patients in remission were consolidated with high dose chemotherapy followed by autologous stem cell transplantation. All patients had a molecular marker (PCR detectable t(11;14) or clonal IgH rearrangement) for MRD. The median follow-up was 6.4 years for the MCL2 cohort and 3.7 years for the MCL3 cohort. 19 miRNAs, previously found to have prognostic significance in MCL (Husby et al EHA 2014), were measured by qRT-PCR and analyzed in concordance with MRD-data. The main endpoint was first event of molecular relapse (MRD-positive sample).
Results Of the 114 patients in the study, 71 (62%) patients became MRD-positive in the follow-up period. Of the 19 examined miRNAs, 10 miRNAs showed unique qPCR melting curves and were analyzed with respect to MRD. Four miRNAs (miR-92a, miR-3687, miR-486-5p and miR-185-5p) were significantly up-regulated in patients who had molecular relapse (t-test; respectively p = 0.010, p = 0.019, p = 0.048, p = 0.043). However miR-18b, previously identified as prognostic marker regarding survival, was not significantly overexpressed. We hereafter investigated if a newly derived prognostic score, the MIPI-B-miR, which incorporates miR-18b with the MIPI-B, could predict molecular relapse. The MIPI-B-miR high-risk patients had significantly shorter time to first molecular relapse than MIPI-B high-risk patients (Figure 1). Functional studies of these aberrantly expressed miRs are ongoing.
Conclusion Patients with molecular relapse had significantly increased levels of miR-92a, miR-3687, miR-486-5p and miR-185-5p, and MIPI-B-miR improved MRD prediction compared to MIPI-B. Aberrant miRNA profiles may be able to predict molecular relapse, and may already at diagnosis identify patients eligible to anti-CD20 antibody maintenance or alternative regimens. However validation in other cohorts is needed.
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Kolstad:Nordic Nanovector: Membership on an entity’s Board of Directors or advisory committees, Research Funding. Räty:GlaxoSmithKline Ltd: Honoraria; Roche Ltd: Membership on an entity’s Board of Directors or advisory committees; Mundipharma: Honoraria.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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