Dimethyl fumarate treatment in relapsed and refractory cutaneous T-cell lymphoma: a multicenter phase 2 study.

Targeted therapies for cutaneous T-cell lymphoma (CTCL) are limited and curative approaches are lacking. Furthermore, relapses and drug induced side effects are major challenges in the therapeutic management of patients with CTCL, creating an urgent need for new and effective therapies. Pathologic constitutive NF-κB activity leads to apoptosis resistance in CTCL cells and, thus, represents a promising therapeutic target in CTCL. In a preclinical study we showed the potential of dimethyl fumarate (DMF) to block NF-κB and, specifically, kill CTCL cells. To translate these findings to applications in a clinical setting, we performed a multicentric phase 2 study evaluating oral DMF therapy in 25 patients with CTCL stages Ib to IV over 24 weeks (EudraCT number 2014-000924-11/NCT number NCT02546440). End points were safety and efficacy. We evaluated skin involvement (using a modified severity weighted assessment tool [mSWAT]), pruritus, quality of life, and blood involvement, if applicable, as well as translational data. Upon skin analysis, 7 of 23 (30.4%) patients showed a response with >50% reduction in the mSWAT score. Patients with high tumor burden in the skin and blood responded best to DMF therapy. Although not generally significant, DMF also improved pruritus in several patients. Response in the blood was mixed, but we confirmed the NF-κB-inhibiting mechanism of DMF in the blood. The overall tolerability of the DMF therapy was very favorable, with mostly mild side effects. In conclusion, our study presents DMF as an effective and excellently tolerable therapeutic option in CTCL to be further evaluated in a phase 3 study or real-life patient care as well as in combination therapies. This trial was registered at www.clinicaltrials.gov as #NCT02546440.

Paediatric onset lymphomatoid papulosis: results of a multicentre retrospective cohort study, on behalf of the EORTC Cutaneous Lymphoma Tumours Group (CLTG).

BACKGROUND: Lymphomatoid Papulosis (LyP) is a rare cutaneous T-cell lymphoproliferative disorder. Comprehensive data on LyP in the paediatric population is scarce. OBJECTIVES: To characterize epidemiological, clinical, histopathological, and prognostic features of paediatric LyP. METHODS: This was a retrospective, multicentre international cohort study including 87 cases of children and adolescents with LyP diagnosed between 1998 and 2022. Patients aged ≤ 18 years old at disease onset were included. Diagnosis was made in each centre based on clinical-pathological correlation. RESULTS: Eighty-seven patients from 12 centres were included. The mean age at onset was 7.0 years (range 3 months-18 years) with a male to female ratio of 2:1. The mean time between onset of first cutaneous lesions and diagnosis was 1.3 years (range 0-14 years). Initial misdiagnosis concerned 26.4% of patients. Initially, LyP was most often misdiagnosed as Pityriasis lichenoides et varioliformis acuta (PLEVA), insect bites, or mollusca contagiosa. Erythematous papules or papulonodules were the most frequent clinical presentation. Pruritus was specifically mentioned for 20.7% of patients. The main histological subtype was type A in 55.1% of the cases. If analysed, monoclonal TCR rearrangement was found in 76.5% of the skin biopsies. The overall survival rate was 100% with follow up at 5 years available for 33 patients and at 15 years for 8 patients. A development of associated haematological malignancy (HM) occurred in 9.6% of the cases (7/73), including four mycosis fungoides (MF) cases, one primary cutaneous anaplastic large cell lymphoma (pc-ALCL), one systemic ALCL and one case of acute myeloid leukaemia. If we compare incidence rates of cancer with the world 0-19 years old population from 2001-2010, we estimate a significantly higher risk of associated malignancy in general, occurring before the age of 19 years old with incidence rate ratio of 87.49 (CI 86.01-88.99). CONCLUSIONS: We report epidemiological data from a large international cohort of children and adolescents with LyP. Overall the prognosis of the disease is good, with excellent survival rates for all patients. Due to increased risk of associated HM, a long-term follow-up should be recommended for LyP patients.

CCR4 in cutaneous T-cell lymphoma: Therapeutic targeting of a pathogenic driver.

New treatments are needed for patients with cutaneous T-cell lymphoma (CTCL), particularly for advanced mycosis fungoides (MF) and Sezary syndrome (SS). The immunopathology of MF and SS is complex, but recent advances in tumor microenvironment understanding have identified CCR4 as a promising therapeutic target. CCR4 is widely expressed on malignant T cells and Tregs in the skin and peripheral blood of patients with MF and SS. The interaction of CCR4 with its dominant ligands CCL17 and CCL22 plays a critical role in the development and progression of CTCL, facilitating the movement into, and accumulation of, CCR4-expressing T cells in the skin, and recruiting CCR4-expressing Tregs into the tumor microenvironment. Expression of CCR4 is upregulated at all stages of MF and in SS, increasing with advancing disease. Several CCR4-targeted therapies are being evaluated, including "chemotoxins" targeting CCR4 via CCL17, CCR4-directed chimeric antigen receptor-modified T-cell therapies, small-molecule CCR4 antagonists, and anti-CCR4 monoclonal antibodies. Only one is currently approved: mogamulizumab, a defucosylated, fully humanized, anti-CCR4, monoclonal antibody for the treatment of relapsed/refractory MF and SS. Clinical trial da1ta confirm that mogamulizumab is an effective and well-tolerated treatment for relapsed/refractory MF or SS, demonstrating the clinical value of targeting CCR4.

Clinical, histopathological and prognostic features of primary cutaneous acral CD8+ T-cell lymphoma and other dermal CD8+ cutaneous lymphoproliferations: results of an EORTC Cutaneous Lymphoma Group workshop.

BACKGROUND: The differential diagnosis of atypical dermal nonepidermotropic CD8+ lymphocytic infiltrates includes a heterogeneous spectrum of lymphoproliferations with overlapping histological and phenotypic features, but divergent clinical manifestations and prognoses. As these neoplasms are rare, more data on their clinicopathological presentation and course are needed. OBJECTIVES: To assess the clinical, histological and immunophenotypic features; outcomes of; and differences between dermal CD8+ lymphoproliferations. METHODS: Retrospective analysis of a series of 46 patients and biopsies by the international EORTC Cutaneous Lymphoma Group. RESULTS: The dermal CD8+ lymphoproliferations (n = 46) could be assigned to one of three groups: (i) cutaneous acral CD8+ T-cell lymphoma (n = 31), characterized mostly by a solitary nodule arising at acral sites, a monotonous dermal infiltrate of small-to-medium-sized CD8+ lymphocytes with a characteristic dot-like pattern of CD68, a low proliferation rate and an excellent prognosis; (ii) primary cutaneous CD8+ peripheral T-cell lymphoma, unspecified/NOS (n = 11), presenting with one or multiple rapidly evolving tumours, mostly medium-sized pleomorphic CD8+ tumour cells with expression of several cytotoxic markers, and high proliferative activity; and (iii) cutaneous CD8+ lymphoproliferations (n = 4), associated with congenital immunodeficiency syndromes in two patients with persisting localized or disseminated violaceous to brownish plaques on the extremities, a histiocyte-rich infiltrate of mostly small CD8+ lymphocytes with subtle atypia and a protracted course; and papular CD8+ eruptions in two patients with acquired immunosuppression. CONCLUSIONS: A constellation of distinct clinical, histopathological and phenotypic features allows discrimination and assignment of dermal CD8+ infiltrates into distinct disease entities. Primary cutaneous acral CD8+ lymphoma, assigned a provisional category in current lymphoma classifications, is a distinct and reproducible entity. A correct diagnosis is essential to avoid unnecessarily aggressive treatment for indolent CD8+ lymphoproliferations and to identify cases with underlying immuno-deficiency or potential for dismal outcome.

Clinical Outcomes of Advanced-Stage Cutaneous Lymphoma under Low-Dose Gemcitabine Treatment: Real-Life Data from the German Cutaneous Lymphoma Network.

BACKGROUND: Gemcitabine is an effective single-agent chemotherapy used in advanced stages of cutaneous T-cell lymphoma (CTCL). However, gemcitabine used in the current standard regimen is frequently associated with adverse events (AE), such as an increased risk for myelosuppression and severe infections. OBJECTIVES: We investigated in this retrospective study the effect of low-dose gemcitabine in pretreated advanced-stage CTCL and in blastic plasmacytoid dendritic cell neoplasia (BPDCN) regarding overall response (OR), progression-free survival (PFS), and AE. MATERIAL AND METHODS: A retrospective, multicenter study was conducted on 64 CTCL and BPDCN patients treated with gemcitabine in average absolute dosage of 1,800 mg/m2 per cycle, which is 50% lower compared to standard dosage of 3,600 mg/m2 per cycle (1,200 mg/m2 day 1, 8, 15). Evaluation of response to therapy and AE was done 4-6 weeks after the sixth cycle. RESULTS: OR was 62% with 11% demonstrating a complete response. The median time of PFS was 12 months and median time to next treatment was 7 months. Only 3/63 patients showed serious side effects, e.g., port infection or acute renal failure. Almost 73% of the patients experienced minor to moderate side effects (CTCAE grade 0-2). Fatigue (27.2%), fever (22.7%), and mild blood count alteration (18.2%) were the most common AE. CONCLUSIONS: This retrospective analysis supports the use of low-dose gemcitabine therapy in CTCL, demonstrating with 62% OR and PFS of 12 months an almost identical response rate and survival as compared to the standard dose therapy reported in previous studies but with a significantly improved safety profile and tolerability.

Chlormethin-Gel zur Behandlung der Mycosis fungoides: Ein Expertenkonsens aus Deutschland, Österreich und der Schweiz (DACH-Region) zum Therapiemanagement.

HINTERGRUND: Chlormethin-Gel ist in Europa zur Therapie von Patienten mit Mycosis fungoides in allen Krankheitsstadien zugelassen. Die optimalen Behandlungsregime hinsichtlich Frequenz, Dosierung, Kombinations- oder Erhaltungstherapien sind noch nicht vollständig etabliert. METHODIK: Zehn in der Erforschung und Behandlung kutaner T-Zell-Lymphome erfahrene Experten aus Deutschland, Österreich und der Schweiz (DACH-Region) wurden schriftlich zu Indikation, Anwendungsfrequenz, Beurteilung des Therapieerfolgs, Begleittherapie, Nebenwirkungen, Kombinationstherapien in späteren Krankheitsstadien, Erhaltungstherapie und Adhärenz im Rahmen der Therapie der Mycosis fungoides mit Chlormethin-Gel befragt. Die strukturiert aufbereiteten Ergebnisse der Umfrage wurden in einer Konsensuskonferenz diskutiert und Empfehlungen zum Management der Therapie mit Chlormethin-Gel entwickelt. ERGEBNISSE: Wesentlich für die Therapie mit Chlormethin-Gel ist ein individuelles, symptomorientiertes Therapiemanagement. Systemische Nebenwirkungen des Wirkstoffs sind wegen der fehlenden systemischen Verfügbarkeit bei topischer Anwendung unwahrscheinlich. Die häufig auftretende allergische oder irritativ-toxische Kontaktdermatitis kann durch eine Anpassung des Therapieregimes, Therapiepausen sowie nebenwirkungsspezifische und unterstützende Maßnahmen häufig beherrscht werden. Ein einschleichender Therapiebeginn mit Anwendung von Chlormethin-Gel jeden zweiten Tag kann die Tolerabilität wesentlich verbessern, insbesondere wenn die Therapie alternierend mit topischen Kortikosteroiden erfolgt. SCHLUSSFOLGERUNGEN: Die Anwendung von Chlormethin-Gel bei Mycosis fungoides wird durch die begleitende Kontaktdermatitis häufig eingeschränkt. Mit einem geeigneten Therapie- und Nebenwirkungsmanagement können vermeidbare Therapieabbrüche verhindert werden und mehr Patienten von der Therapie profitieren.

The optimal use of chlormethine gel for mycosis fungoides: An expert consensus from Germany, Austria and Switzerland (DACH region).

BACKGROUND: In Europe chlormethine gel is licensed for the management of patients with mycosis fungoides of all stages. However, the optimal regimen regarding frequency and dosing as well as combination and maintenance therapy is not well established. METHODS: Ten experts experienced in research and management of cutaneous T-cell lymphomas from Germany, Austria, and Switzerland (DACH region) were asked in written form to report on indication for chlormethine gel, frequency of use, monitoring, concomitant therapies, adverse effects, combination therapies in later stages of the disease, maintenance therapy, and adherence to this therapy for mycosis fungoides. The structured answers were discussed in a consensus conference and recommendations were developed. RESULTS: Essential for therapy with chlormethine gel is an individualized and symptom-oriented management. Because of the lack of systemic resorption of topically administered chlormethine gel, systemic adverse events are unlikely. An allergic or irritative-toxic contact dermatitis is common but manageable with adaptation of the regimen, interruption of administration, and symptom-specific supportive measurements. A step-up initial approach with application of chlormethine gel every other day is associated with a better tolerability, especially if it is alternated with topical corticosteroids. CONCLUSIONS: The use of chlormethine gel in the management of mycosis fungoides is often limited by a concomitant contact dermatitis. An adequate therapeutic regimen and the management of adverse effects can preclude an unnecessary withdrawal of therapy so that more patients can benefit from this treatment option.

Combined inhibition of Bcl-2 and NFκB synergistically induces cell death in cutaneous T-cell lymphoma.

Therapeutic options for cutaneous T-cell lymphoma (CTCL) are limited and curative treatment regimens are not available. Thus, new targeted and well-tolerated therapeutic approaches are urgently needed. In this respect, we have recently shown that dimethyl fumerate (DMF) inhibits NF-κB acting as a survival factor in CTCL. Similarly, inhibition of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) has been shown to induce cell death in CTCL especially when combined with histone deacetylase inhibitors. Therefore, we hypothesized that inhibition of Bcl-2 should potentiate NF-κB inhibition in a novel combination treatment of CTCL. We show that, in vitro, the Bcl-2 inhibitors ABT-199 and ABT-263 induced specific cell death in primary CD4+ cells from CTCL patients as well as in the CTCL cell line SeAx, but not in T cells of healthy donors nor in the CTCL cell line HH, which lacks Bcl-2. Combined treatment with ABT-199 and DMF caused synergistic cell death specifically in CTCL cells engaging 2 independent signaling pathways. To verify these findings in vivo, we performed combined ABT-199 and DMF treatment in a xenograft mouse model for CTCL. The combined treatment effectively reduced tumor growth and increased overall survival via synergistic induction of CTCL cell death and suppression of tumor cell proliferation. Essentially, the combination treatment was superior to ABT-199 monotherapy with respect to both efficacy and tolerability. To sum up, our data provide proof of principle for the therapeutic potential of combining Bcl-2 and NF-κB inhibitors in treating CTCL. Next, this potential should be explored further in a clinical study.

A PP4 holoenzyme balances physiological and oncogenic nuclear factor-kappa B signaling in T lymphocytes.

Signal transduction to nuclear factor-kappa B (NF-κB) involves multiple kinases and phosphorylated target proteins, but little is known about signal termination by dephosphorylation. By RNAi screening, we have identified protein phosphatase 4 regulatory subunit 1 (PP4R1) as a negative regulator of NF-κB activity in T lymphocytes. PP4R1 formed part of a distinct PP4 holoenzyme and bridged the inhibitor of NF-κB kinase (IKK) complex and the phosphatase PP4c, thereby directing PP4c activity to dephosphorylate and inactivate the IKK complex. PP4R1 expression was triggered upon activation and proliferation of primary human T lymphocytes and deficiency for PP4R1 caused sustained and increased IKK activity, T cell hyperactivation, and aberrant NF-κB signaling in NF-κB-addicted T cell lymphomas. Collectively, our results unravel PP4R1 as a previously unknown activation-associated negative regulator of IKK activity in lymphocytes whose downregulation promotes oncogenic NF-κB signaling in a subgroup of T cell lymphomas.

[Single-center retrospective analysis of extracorporal photopheresis in clinical practice : Peripheral venous compared to central venous access]. / Unizentrische, retrospektive Analyse der praktischen Durchführung der extrakorporalen Photopherese : Periphervenöser und zentralvenöser Zugang im Vergleich.

BACKGROUND: Extracorporal photopheresis (ECP) was shown to be effective without severe side effects in the treatment of cutaneous T cell lymphoma (CTCL) and graft versus host disease (GvHD). However, only few studies investigated the practical aspects of ECP. METHODS: Treatment protocols of 2038 ECP procedures in 52 patients (CTCL, n = 29; GvHD, n = 15; other, n = 8) were evaluated. The patients were treated with the UVAR® XTS™ ECP system (Therakos, Inc. Johnson & Johnson, Raritan, NJ, USA) between 2001 and 2010. All patients started with a peripheral venous access. During the course of treatment 7 patients were treated via a port and 4 via a central venous catheter. RESULTS: In all, 1765 (86.6%) treatments were performed with a peripheral venous access; 239 (11.7%) ECPs were done via a port and 34 (1.7%) via a central venous catheter. The peripheral venous access showed a higher flow rate and longer photoactivation time. ECPs via port lead to higher UV-irradiated volumes, longer treatment times and higher differences in systolic blood pressure. The following side effects were observed: being unwell (n = 13), hypo- (n = 13) and hypertension (n = 7), vertigo (n = 4), headache (n = 4), shortness of breath (n = 4), fever (n = 3) and metallic taste (n = 3). Technical complications such as problems with venous access (9.6%) occurred in 385 (18.9%) treatments. CONCLUSIONS: Peripheral venous access should be preferred for ECP treatments.

Dimethyl fumarate restores apoptosis sensitivity and inhibits tumor growth and metastasis in CTCL by targeting NF-κB.

Despite intensive efforts in recent years, a curative therapy for cutaneous T-cell lymphoma (CTCL) has not yet been developed. Therefore, the establishment of new therapeutic approaches with higher efficacy rates and milder side effects is strongly desired. A characteristic feature of the malignant T-cell population in CTCL is resistance toward cell death resulting from constitutive NF-κB activation. Therefore, NF-κB-dependent cell death resistance represents an interesting therapeutic target in CTCL because an NF-κB-directed therapy would leave bystander T cells widely unaffected. We investigated the effects of dimethyl fumarate (DMF) on CTCL cells in vitro and in vivo. DMF induced cell death in primary patient-derived CD4(+) cells and CTCL cell lines, but hardly in T cells from healthy donors. DMF-induced cell death was linked specifically to NF-κB inhibition. To study the impact of DMF in vivo, we developed 2 CTCL xenograft mouse models with different cutaneous localizations of the T-cell infiltrate. DMF treatment delayed the growth of CTCL tumors and prevented formation of distant metastases. In addition, DMF induced increased cell death in primary CTCL tumors and in liver metastases. In summary, DMF treatment represents a remarkable therapeutic option in CTCL because it restores CTCL apoptosis in vitro and in preclinical models in vivo and prevents spreading of the disease to distant sites. DMF treatment is of particular promise in CTCL because DMF is already in successful clinical use in the treatment of psoriasis and multiple sclerosis allowing fast translation into clinical studies in CTCL.

Cutaneous B-cell lymphomas - pathogenesis, diagnostic workup, and therapy.

Cutaneous B-cell lymphomas (CBCLs) comprise a group of mature lymphoproliferative B-cell disorders that primarily affect the skin. Characterized by great biological and clinical variability among its various subtypes, CBCLs fundamentally differ from primary nodal or systemic B-cell lymphomas. Given their uncomplicated course and excellent prognosis, lymphoma classifications rank primary cutaneous marginal zone lymphoma (PCMZL) and primary cutaneous follicle center lymphoma (PCFCL) as indolent CBCLs. By contrast, diffuse large B-cell lymphoma, leg type (DLBCL-LT) in particular, represent more aggressive lymphoma variants associated with a poorer prognosis. Therapeutic decisions and diagnostic procedures are based on the exact histological and immunohistochemical classification as well as the exclusion of systemic involvement and thus differentiation from nodal and systemic lymphomas. In this context, the diagnostic workup should also include molecular biology methods. Primary therapeutic options for indolent CBCL lesions include surgery and radiation therapy, as well as systemic treatment with rituximab (anti-CD20 antibody) in case of dissemination. More aggressive CBCLs usually require a combination of rituximab and polychemotherapy, primarily the CHOP regimen or modifications thereof. Given that the pathogenesis and biology of CBCLs has not been conclusively elucidated, and given the limited therapeutic armamentarium available, there is great need for comprehensive research, especially with respect to DLBCL-LT.

B-Zell-Lymphome der Haut - Pathogenese, Diagnostik und Therapie.

Primär kutane B-Zell-Lymphome (PCBCL) beschreiben reifzellige lymphoproliferative Erkrankungen der B-Zell-Reihe, die primär die Haut betreffen. Die Biologie und der klinische Verlauf der einzelnen PCBCL-Subtypen variieren untereinander stark und unterscheiden sich grundsätzlich von primär nodalen und systemischen B-Zell-Lymphomen. Primär kutane Marginalzonenlymphome (PCMZL) und primäre kutane follikuläre Keimzentrumslymphome (PCFCL) werden auf Grund ihres unkomplizierten Verlaufs und ihrer exzellenten Prognose zu den indolenten PCBCL gezählt. Demgegenüber stellen die diffus großzelligen B-Zell-Lymphome, hauptsächlich vom Beintyp (DLBCL, LT) die aggressiveren PCBCL-Varianten mit schlechterer Prognose dar. Für die Ausbreitungsdiagnostik und die Therapieentscheidung sind eine genaue histologische und immunhistochemische Klassifizierung sowie der Ausschluss einer systemischen Beteiligung in Abgrenzung zu nodalen oder systemischen Lymphomen notwendig. Die Diagnostik sollte dabei durch molekularbiologische Untersuchungen unterstützt werden. Therapeutisch stehen für die indolenten PCBCL primär operative und radioonkologische Maßnahmen im Vordergrund sowie eine Systemtherapie mit dem CD20-Antikörper Rituximab bei disseminiertem Befall. Die aggressiveren Varianten sollten in erster Linie mit Kombinationen aus Rituximab und Polychemotherapieschemata wie z. B. dem CHOP-Schema oder Modifikationen davon behandelt werden. Auf Grund der in allen seinen Einzelheiten noch nicht vollständig verstandenen Pathogenese und Biologie sowie des begrenzten Therapiespektrums der PCBCL besteht hier, speziell beim DLBCL, LT, noch erheblicher Forschungsbedarf.

Sézary syndrome: old enigmas, new targets.

Sézary syndrome, the leukemic variant of cutaneous T-cell lymphoma, is still an enigmatic disease with a fatal prognosis. Recent research, however, has identified a multitude of dysregulated molecular pathways that contribute to malignant transformation and therapy resistance of Sézary cells (SC). With respect to T-cell development, SC either represent naive T cells, T effector memory or T central memory cells. Functionally, SC may differentiate into Th2, Treg, or even Th17 cells. Despite their plasticity, SC express characteristic diagnostic marker proteins including CD158k, CD164, FcRL3, and PD-1 as well as skin-homing receptors such as CLA and CCR4. Already tested in (pre)clinical trials, CD158k, PD-1, CTLA-4, and CCR4 also represent promising therapeutic targets. Molecular alterations in SC include transcription factors such as STAT3, 4, and 5, as well as TWIST1 and TOX. TWIST1 induces expression of DNM3os containing the miR-199a2/214 cluster, a key hub controlling multiple cancer networks. In addition, activation of NFκB and the MAPK pathway as well as altered TCR signaling cause apoptosis resistance. Recently, whole genome and exome sequencing has revealed somatic copy number variations as predominant mutations in SC, primarily affecting apoptosis, NFκB signaling, DNA integrity, and T-cell activation. In order to facilitate development of novel therapies, improved in vivo models, which better reflect the pathogenesis and clinical course of Sézary syndrome, are currently being generated.

Aggressive primary cutaneous B-cell lymphomas show increased Angiopoietin-2-induced angiogenesis.

Primary cutaneous large B-cell lymphomas, leg type (PCLBCL/LT) are primary cutaneous B-cell lymphoma (PCBCL) with an intermediate prognosis. Therefore, antracycline-based polychemotherapy combined with rituximab has been recommended as first-line treatment. Yet, despite this regimen, the 5-year survival rate remains 50-66% only. Angiogenesis, the formation of a vascular network, is essential for the pathogenesis of nodal lymphomas. So far, no study has analysed angiogenesis and its key factors in PCLBCL/LT. The present study was aimed at characterizing angiogenesis in PCLBCL/LT to identify the angiogenic molecules as potential therapeutic targets. The intra-tumoral microvessel density (MVD) was assessed by immunohistochemical studies of CD20 and CD31. The MVD was higher in PCLBCL/LT compared with indolent PCBCL. Analyses of open-source microarray data showed correlation between the angiogenic molecule angiopoietin-2 (Ang-2) and pan-endothelial cell markers. ELISA studies determined a shift between Ang-2 and Ang-1 towards Ang-2 in the peripheral blood of PCLBCL/LT patients. Immunofluorescence costainings against the Ang receptor Tie2/angiogenic integrins/CD34 revealed that the vasculature in both aggressive and indolent PCBCL tumors harbours an endothelial cell subpopulation with reduced expression of Tie2. In contrast, the alternative Ang-2 binding partners, angiogenic integrins, are strongly expressed in PCBCL. In line with these findings, downstream targets of Ang-2-integrin signalling, that is phosphorylation of focal adhesion kinase at Tyr397, and sprouting angiogenesis are enhanced in PCLBCL/LT. Our data present Ang-2 as a promising therapeutic target and anti-angiogenic therapy as a new line in treatment of PCLBCL/LT as a hitherto intractable disease.

Liver cell death and anemia in Wilson disease involve acid sphingomyelinase and ceramide.

Wilson disease is caused by accumulation of Cu(2+) in cells, which results in liver cirrhosis and, occasionally, anemia. Here, we show that Cu(2+) triggers hepatocyte apoptosis through activation of acid sphingomyelinase (Asm) and release of ceramide. Genetic deficiency or pharmacological inhibition of Asm prevented Cu(2+)-induced hepatocyte apoptosis and protected rats, genetically prone to develop Wilson disease, from acute hepatocyte death, liver failure and early death. Cu(2+) induced the secretion of activated Asm from leukocytes, leading to ceramide release in and phosphatidylserine exposure on erythrocytes, events also prevented by inhibition of Asm. Phosphatidylserine exposure resulted in immediate clearance of affected erythrocytes from the blood in mice. Accordingly, individuals with Wilson disease showed elevated plasma levels of Asm, and displayed a constitutive increase of ceramide- and phosphatidylserine-positive erythrocytes. Our data suggest a previously unidentified mechanism for liver cirrhosis and anemia in Wilson disease.

Down-regulation of renal klotho expression by Shiga toxin 2.

BACKGROUND/AIMS: Shiga toxin 2 may trigger classical hemolytic uremic syndrome (HUS) eventually leading to renal failure. Klotho, a transmembrane protein, protease and hormone mainly expressed in kidney is involved in the regulation of renal phosphate excretion and also retains renal protective effects. Renal failure is associated with renal depletion of klotho. The present study explored the influence of Shiga toxin 2 on renal klotho expression. METHODS: Mice were injected with either solvent or Shiga toxin 2 and urinary flow rate and phosphate excretion were determined in metabolic cages. Renal transcript levels were measured by quantitative RT-PCR and renal protein abundance by Western blotting. Plasma concentrations of 1,25(OH)2D3 and FGF23 were determined by ELISA and plasma phosphate and urea concentrations by photometry. RESULTS: Shiga toxin 2 treatment was followed by increase of plasma urea concentration, urinary flow rate and renal phosphate excretion but not of plasma phosphate concentration. Shiga toxin 2 treatment strongly decreased klotho mRNA expression and klotho protein abundance in renal tissue. Shiga toxin 2 treatment further increased tumor necrosis factor (Tnfα) mRNA levels, as well as protein abundance of phosphorylated p38 MAPK in renal tissue. The treatment significantly increased renal Cyp27b1 and decreased renal Cyp24a1 mRNA levels without significantly altering plasma 1,25(OH)2D3 levels. Shiga toxin 2 treatment was further followed by increase of plasma FGF23 concentrations. CONCLUSION: Shiga toxin 2 treatment stimulated Tnfα transcription, down-regulated renal klotho expression and increased FGF23 formation, effects presumably contributing to renal tissue injury.