Mycosis fungoides (MF) is a low-grade cutaneous T cell lymphoma of unknown etiology. In this report, the Jak͞Stat (Janus kinase͞signal transducer and activator of transcription) signaling pathway was investigated in tumor cell lines established from skin biopsy specimens from a patient with MF. Jaks link cytokine receptors to Stats, and abnormal Jak͞Stat signaling has been observed in some hemopoietic cancers. In MF tumor cells, a slowly migrating isoform of Stat3, Stat3 sm , was found to be constitutively activated, i.e., (i) Stat3 sm was constitutively phosphorylated on tyrosine residues, and tyrosine phosphorylation was not enhanced by growth factor stimulation; (ii) band shift assays and immunoprecipitations of DNA͞Stat complexes showed constitutive DNA-binding properties of Stat3 sm ; and (iii) Stat3 sm was constitutively associated with Jak3. The abnormal activation of Stat3 sm was highly specific. Thus, neither the fast migrating isoform of Stat3 (Stat3 fm ) nor other Stats (Stat1, Stat2, and Stat4 through Stat6) were constitutively activated. The Jak kinase inhibitor, tyrphostin AG490, blocked the constitutive activation of Stat3 sm and inhibited spontaneous as well as interleukin 2-induced growth of MF tumor cells. In conclusion, we have provided evidence for an abnormal Jak͞ Stat signaling and growth regulation in tumor cells obtained from affected skin of an MF patient.

Both common forms of diabetes have an inflammatory pathogenesis in which immune and metabolic factors converge on interleukin-1β as a key mediator of insulin resistance and β-cell failure. In addition to improving insulin resistance and preventing β-cell inflammatory damage, there is evidence of genetic association between diabetes and histone deacetylases (HDACs); and HDAC inhibitors (HDACi) promote β-cell development, proliferation, differentiation and function and positively affect late diabetic microvascular complications. Here we review this evidence and propose that there is a strong rationale for preclinical studies and clinical trials with the aim of testing the utility of HDACi as a novel therapy for diabetes.

Interleukin-2 (IL-2

Signal transducers and activators of transcription (STATs) are rapidly phosphorylated on tyrosine residues in response to cytokine and growth factor stimulation of cell surface receptors. STATs hereafter are translocated to the nucleus where they act as transcription factors. Recent reports suggest that serine phosphorylation of STATs also is involved in the regulation of STAT-mediated gene transcription. Here, we studied the role of serine͞threonine phosphatases in STAT3 signaling in human antigen-specific CD4 ؉ T cell lines and cutaneous T cell lymphoma lines, expressing a constitutively activated STAT3. We show that an inhibitor of protein phosphatases (PPs) PP1͞PP2A, calyculin A, induces (i) phosphorylation of STAT3 on serine and threonine residues, (ii) inhibition of STAT3 tyrosine phosphorylation and DNA binding activity, and (iii) relocation of STAT3 from the nucleus to the cytoplasm. Similar results were obtained with other PP2A inhibitors (okadaic acid, endothall thioanhydride) but not with inhibitors of PP1 (tautomycin) or PP2B (cyclosporine A). Pretreatment with the broad serine͞threonine kinase inhibitor staurosporine partly blocked the calyculin A-induced STAT3 phosphorylation, whereas inhibitors of serine͞threonine kinases, such as mitogen-activated protein kinase-1 extracellular-regulated kinase-kinase, mitogenactivated protein p38 kinase, and phosphatidylinositol 3-kinase, did not. In conclusion, we provide evidence that PP2A plays a crucial role in the regulation of STAT3 phosphorylation and subcellular distribution in T cells. Moreover, our findings suggest that the level of STAT3 phosphorylation is balanced between a staurosporine-sensitive kinase(s) and PP2A.STATs (signal transducers and activators of transcription) are latent cytoplasmic transcription factors that upon activation translocate into the nucleus where they activate target genes (reviewed in ref. 1). At present, seven STATs have been cloned, all of which have an Src homology 2 domain near their carboxyl terminus and a tyrosine residue near position 700 (e.g., Y705 in STAT3). Upon ligation, cytokine and growth factor receptor-associated Janus kinases (JAKs) become activated, possibly by transphosphorylation and͞or autophosphorylation. Once activated, JAKs phosphorylate the receptor on key tyrosine residues, which leads to recruitment of STAT proteins, which in turn are tyrosine-phosphorylated by JAKs. Phosphorylated STAT proteins homodimerize or heterodimerize through reciprocal Src homology 2-phosphotyrosine interactions and translocate to the nucleus where they bind specific DNA elements and regulate transcriptional activity of target genes (reviewed in refs. 1-3).STATs also are serine-phosphorylated in response to ligation of many cytokine and growth factor receptors (reviewed in ref. 4). The major site for serine phosphorylation in STAT1 and STAT3 is residue 727 (5), allthough additional serine phosphorylation sites have been proposed (6). Serine phosphorylation of STAT proteins modulate the DNA binding and͞or transcri...

IMPORTANCE Medication overuse headache (MOH) is a disabling, globally prevalent disorder representing a well-known and debated clinical problem. Evidence for the most effective treatment strategy is needed.OBJECTIVE To compare 3 treatment strategies for MOH. DESIGN, SETTING, AND PARTICIPANTSThis open-label, randomized clinical trial with 6 months of follow-up was conducted in the tertiary sector at the Danish Headache Center, Glostrup, from October 25, 2016, to June 28, 2019. Of 483 patients with MOH referred during the inclusion period, 195 met the criteria consisting of migraine and/or tension-type headache, 18 years or older, eligibility for outpatient treatment, no severe physical or psychiatric disorder, no other addiction, and not pregnant or breastfeeding. Of these, 75 refused participation and 120 were included. Data were analyzed from July 3 to September 6, 2019.INTERVENTIONS Random assignment (1:1:1 allocation) to 1 of the 3 outpatient treatments consisting of (1) withdrawal plus preventive treatment, (2) preventive treatment without withdrawal, or (3) withdrawal with optional preventive treatment 2 months after withdrawal. MAIN OUTCOMES AND MEASURESThe primary outcome was change in headache days per month after 6 months. Predefined secondary outcomes were change in monthly migraine days, use of short-term medication, pain intensity, number of responders, patients with remission to episodic headache, and cured MOH. RESULTSOf 120 patients, 102 (mean [SD] age, 43.9 [11.8] years; 81 women [79.4%]) completed the 6-month follow-up. Headache days per month were reduced by 12.3 (95% CI, 9.3-15.3) in the withdrawal plus preventive group, by 9.9 (95% CI, 7.2-12.6) in the preventive group, and by 8.5 (95% CI, 5.6-11.5) in the withdrawal group (P = .20). No difference was found in reduction of migraine days per month, use of short-term medication, or headache intensity. In the withdrawal plus preventive group, 23 of 31 patients (74.2%) reverted to episodic headache, compared with 21 of 35 (60.0%) in the preventive group and 15 of 36 (41.7%) in the withdrawal group (P = .03). Moreover, 30 of 31 patients (96.8%) in the withdrawal plus preventive group were cured of MOH, compared with 26 of 35 (74.3%) in the preventive group and 32 of 36 (88.9%) in the withdrawal group (P = .03). These findings corresponded to a 30% (relative risk, 1.3; 95% CI, 1.1-1.6) increased chance of MOH cure in the withdrawal plus preventive group compared with the preventive group (P = .03).CONCLUSION AND RELEVANCE All 3 treatment strategies were effective, but based on these findings, withdrawal therapy combined with preventive medication from the start of withdrawal is recommended as treatment for MOH.

A characteristic feature of neoplastic transformation is the loss of external control by cytokines and extracellular matrix of cellular differentiation, migration, and mitogenesis. Because suppressors of cytokine signaling (SOCS) proteins are negative regulators of cytokine-induced signaling, it has been hypothesized that an aberrant SOCS expression plays a role in neoplastic transformation. This study reports on a constitutive SOCS-3 expression in cutaneous T-cell lymphoma (CTCL) cell lines. SOCS-3 protein is constitutively expressed in tumor cell lines (but not in nonmalignant T cells) obtained from affected skin from a patient with mycosis fungoides (MF) and from peripheral blood from a patient with Sezary syndrome (SS). In contrast, constitutive SOCS-3 expression is not found in the leukemic Jurkat T-cell line, the MOLT-4 acute lymphoblastic leukemia cell line, and the monocytic leukemic cell line U937. Expression of SOCS-3 coincides with a constitutive activation of STAT3 in CTCL tumor cells, and stable transfection of CTCL tumor cells with a dominant negative STAT3 strongly inhibits SOCS-3 expression, whereas transfection with wild-type STAT3 does not. Moreover, the reduced SOCS-3 expression in cells transfected with the dominant negative STAT3 is associated with an increased sensitivity to interferon-alpha (IFN-alpha). In conclusion, evidence is provided for a constitutive SOCS-3 expression in cancer cells obtained from patients with CTCL. Moreover, the findings indicate that the aberrant expression of SOCS-3 is mediated by a constitutive activation of STAT3 in CTCL cells and affects the IFN-alpha sensitivity of these cells. (Blood. 2001;97:1056-1062)

Summary Antagonism between growth-promoting and stress-responsive signaling influences tissue homeostasis and longevity in metazoans. The transcription factor FoxO is central to this regulation, affecting cell proliferation, stress responses, apoptosis, and longevity. Insulin/IGF signaling promotes FoxO phosphorylation, causing its interaction with 14-3-3 molecules. The consequences of this interaction for FoxO-induced biological processes and for the regulation of lifespan in higher organisms remain unclear. Significant complexities in the effects of 14-3-3 proteins on lifespan have been uncovered in Caenorhabditis elegans, suggesting both positive and negative roles for 14-3-3 proteins in the control of aging. Using genetic and biochemical studies, we show here that 14-3-3ε antagonizes FoxO function in Drosophila. We find that dFoxO and 14-3-3ε proteins interact in vivo and that this interaction is lost in response to oxidative stress. Loss of 14-3-3ε results in increased stress-induced apoptosis, growth repression and extended lifespan of flies, phenotypes associated with elevated FoxO function. Our results further show that increased expression of 14-3-3ε reverts FoxO-induced growth defects. 14-3-3ε thus serves as a central modulator of FoxO activity in the regulation of growth, cell death and longevity in vivo.

Aims/hypothesis Histone deacetylases (HDACs) are promising pharmacological targets in cancer and autoimmune diseases. All 11 classical HDACs (HDAC1-11) are found in the pancreatic beta cell, and HDAC inhibitors (HDACi) protect beta cells from inflammatory insults. We investigated which HDACs mediate inflammatory beta cell damage and how the islet content of these HDACs is regulated in recent-onset type 1 diabetes. Methods The rat beta cell line INS-1 and dispersed primary islets from rats, either wild type or HDAC1-3 deficient, were exposed to cytokines and HDACi. Molecular mechanisms were investigated using real-time PCR, chromatin immunoprecipitation and ELISA assays. Pancreases from healthy children and children with type 1 diabetes were assessed using immunohistochemistry and immunofluorescence. Results Screening of 19 compounds with different HDAC selectivity revealed that inhibitors of HDAC1, -2 and -3 rescued INS-1 cells from inflammatory damage. Small hairpin RNAs against HDAC1 and -3, but not HDAC2, reduced pro-inflammatory cytokine-induced beta cell apoptosis in INS-1 and primary rat islets. The protective properties of specific HDAC knock-down correlated with attenuated cytokine-induced iNos expression but not with altered expression of the proinflammatory mediators Il1α, Il1β, Tnfα or Cxcl2. HDAC3 knock-down reduced nuclear factor κB binding to the iNos promoter and HDAC1 knock-down restored insulin secretion. In pancreatic sections from children with type 1 diabetes of recent onset, HDAC1 was upregulated in beta cells whereas HDAC2 and -3 were downregulated in comparison with five paediatric controls. Conclusions/interpretation These data demonstrate nonredundant functions of islet class I HDACs and suggest that targeting HDAC1 and HDAC3 would provide optimal protection of beta cell mass and function in clinical islet transplantation and recent-onset type 1 diabetic patients.