Hans-Eckart Schaefer

ΔF508-CFTR Causes Constitutive NF-κB Activation through an ER-Overload Response in Cystic Fibrosis Lungs

Abstract The clinical course of Cystic Fibrosis is characterized by recurrent pulmonary infections which ultimately lead to death by respiratory failure. The most common CF causing mutation, δF508-CFTR, produces an incorrectly folded protein, which accumulates within the endoplasmic reticulum. However, the molecular mechanism by which the δF508-CFTR protein facilitates pulmonary infection and inflammation remains unclear. Here we show that the expression of δF508-CFTR causes a constitutive activation of the proinflammatory transcription factor NFκB by eliciting an ER stress reaction, the ERoverload response. This endogenous NFκB activation stimulates the transcription of proinflammatory cytokines thereby commencing an inflammatory cascade within the CF lung.

Zytochemischer Polymorphismus der sauren Phosphatase bei Haarzell-Leukämie

ZusammenfassungMit Hilfe zytochemischer Untersuchungen kann bei der Haarzell-Leukämie ein Polymorphismus der sauren Phosphatase (SP) nachgewiesen werden. In einem von vier untersuchten Fällen fehlt jegliche SP in den Haarzellen, bei zweien ist nur tartratsensible SP nachweisbar, im vierten tartratresistente SP in hoher Aktivität. Nach unseren Erfahrungen spricht das Fehlen tartratresistenter SP nicht gegen die Diagnose Haarzell-Leukämie.SummaryIn four cases of hairy cell leukemia a cytochemical polymorphism concerning acid phosphatase (AP) is evident. Any AP is lacking in all hairy cells of one case; only tartrate inhibitable AP is occurring in two cases; in another case tartrate resistant AP is found in high activity. Thus, the lack of tartrate resistant AP seems not to be an argument against hairy cell leukemia.

c-kit (CD117) Expression in Human Tumors and its Prognostic Value: An Immunohistochemical Analysis

Abstractc-kit functions as a tyrosine kinase receptor and represents a target for small molecule kinase inhibitors. The expression pattern for c-kit was studied in different human tumor types to their correlation with prognosis. Paraffin-embedded tumor tissues from 282 patients were analyzed immunohistochemically for c-kit expression. Survival and follow-up data were available from 192/282 (68%) patients. c-kit immunopositivity was found in 62/282 (22%) cases. c-kit expression was found in 14/83 (17%) colorectal cancers, in 13/62 (21%) breast cancers, in 7/20 sarcomas (35%), in 5/14 (36%) renal cell carcinomas, in 2/12 ovarian cancers (17%) and in 2/12 (17%) hepatocellular carcinomas. We found no significant correlation between c-kit expression and prognosis although a trend to a worse prognosis in patients with c-kit positive tumors could be observed. Expression of c-kit was found in tumor samples with varying intensities and infrequently.

Vorkommen von Tartrat-resistenter saurer Phosphatase in verschiedenen Zelltypen des lympho-retikulären und hämopoetischen Systems

Die Tartrat-resis tente saure Phosphatase (TSP) hat als Markerenzym der HaarzellLeukiimie Aufmerksamkei t gefunden. Die biologische Bedeutung dieses Isoenzyms bleibt riitselhaft, solange fiber ein V o r k o m m e n dieses Fermentes in nicht-neoplastischen Zellen wenig bekannt ist. Auch ist nicht eindeutig gekliirt, bei welchen anderen Leukiimiearten TSP auftreten kann. Immerh in haben Yam et al. [9] zumindest biochemisch ger inge Aktivit~iten yon TSP bei verschiedenen Nicht-Haarzell-Leuk~imien erwithnt. Wi t haben daher das Vorhandense in zytochemisch nachweisbarer TSP in nicht-neoplast ischen Zel len yon Knochenmark und Lymphkno ten sowie in Blutausstrichen yon 14 akut und 12 chronisch ver laufenden lymphat ischen Leuk~imien, ferner yon 13 chronischen Myelosen und 8 verschiedenart igen akuten myeloischen Leuk/imien (myelo-monozytitr , promyelozyt~ir, myeloblast~tr) iiberpriift .

Primary thymic carcinoid with Cushing's syndrome

In a 52-year-old Caucasian man osteopoikilosis had been misdiagnosed roentgenologically 2 years before his death. Gradually he developed Cushings syndrome and ultimately superior vena caval obstruction. At autopsy a primary thymic carcinoid with extensive osteoblastic bone metastasis was found. Immunohistochemically the tumor was shown to be positive for adrenocorticotropic hormone (ACTH), cytokeratin (KL1), neuron-specific enolase, synaptophysin, chromogranin and glucagon. Remarkably the tumour was negative for serotonin despite high urinary hydroxyindolacetic acid levels. Bilateral hyperplasia of the adrenal cortex was found. The adenohypophysis showed a considerable reduction of ACTH-producing cells and numerous Crookes cells with a characteristic immunohistochemical pattern.

Eosinophilenleukämie, eine unreifzellige Myelose mit Chloroacetatesterase-positiver Eosinophilie

ZusammenfassungZwei Fälle einer sogenannten Eosinophilenleukämie werden hinsichtlich morphologischer und klinischer Aspekte beschrieben. Dabei handelt es sich um eine spezielle Form akuter Myelosen, die durch folgende Besonderheiten gekennzeichnet ist: hohe Eosinophilie der intra- und teilweise auch extramedullären Infiltrate bei relativ geringer Bluteosinophilie; intra- und extramedulläre Blastenproliferation mit starker Ausschwemmung; kennzeichnende zytochemische Atypien in Form einer ungewöhnlichen Aktivität der Naphthol-AS-D-chloroacetat-esterase und einer stark positiven PAS-Reaktion; besonders elektronenmikroskopisch deutlich sichtbare Dissozation und teilweise Arretierung der eosinophilen Granulogenese. — Die mitgeteilten Fälle zeigen Übereinstimmungen mit anderen, in der Literatur teilweise ebenfalls als “Eosinophilenleukämie” klassifizierten Formen. In diesem Zusammenhang wird die Problematik monophyler Leukosen unter Berücksichtigung der durch die zytochemische Analyse exakt bestimmbaren Differenzierung extramedullärer leukotischer Infiltrate diskutiert.SummaryTwo cases of a so-called eosinophilic leukemia are described with regard to morphological and clinical aspects. These cases are concerning a special variant of acute myelosis characterized by the following items: high eosinophilia of the intra- and in part of the extramedullary infiltrates contrasted by a moderate or low blood eosinophil count; intra- and extramedullary blast cell proliferation with blastic leukocytosis; cytochemical atypism of the eosinophils: unusual naphthol-AS-D-chloroacetatesterase activity, strong PAS-reaction; disarrangement of granulogenesis as revealed by electron microscopy. The presented cases are similar to others, in literature classified as “eosinophilic leukemia”. In this context the problem of monophylic leukemia is discussed in consideration of results obtained by cytochemical analysis of extramedullary leukemic infiltrates.

A Novel Thymoma-Associated Immunodeficiency with Increased Naive T Cells and Reduced CD247 Expression

The mechanisms underlying thymoma-associated immunodeficiency are largely unknown, and the significance of increased blood γδ Τ cells often remains elusive. In this study we address these questions based on an index patient with thymoma, chronic visceral leishmaniasis, myasthenia gravis, and a marked increase of rare γδ T cell subsets in the peripheral blood. This patient showed cutaneous anergy, even though he had normal numbers of peripheral blood total lymphocytes as well as CD4+ and CD8+ T cells. Despite his chronic infection, analyses of immunophenotypes and spectratyping of his lymphocytes revealed an unusual accumulation of naive γδ and αβ T cells, suggesting a generalized T cell activation defect. Functional studies in vitro demonstrated substantially diminished IL-2 and IFN-γ production following TCR stimulation of his “untouched” naive CD4+ T cells. Biochemical analysis revealed that his γδ and αβ T cells carried an altered TCR complex with reduced amounts of the ζ-chain (CD247). No mutations were found in the CD247 gene that encodes the homodimeric ζ protein. The diminished presence of CD247 and increased numbers of γδ T cells were also observed in thymocyte populations obtained from three other thymoma patients. Thus, our findings describe a novel type of a clinically relevant acquired T cell immunodeficiency in thymoma patients that is distinct from Good’s syndrome. Its characteristics are an accumulation of CD247-deficient, hyporresponsive naive γδ and αβ T cells and an increased susceptibility to infections.

Familial and Metachronous Malignant Lymphoma: Absence of Constitutional p53 Mutations

Familial and metachronous aggregations of malignant lymphoma are well‐documented, but the molecular basis of a predisposition for development of lymphoma is as yet unclear. Malignant lymphomas have been described as part of the spectrum of neoplasias in Li‐Fraumeni syndrome (LFS), which is associated with constitutional mutations of p53. However, p53 germline mutations have also, albeit less frequently, been described in patients not fitting the clinical definition of LFS. To clarify whether a genetic predisposition for lymphoma is associated with constitutional p53 mutations, DNA from normal blood lymphocytes of 12 lymphoma patients with a family history of lymphoma and/or with metachronous lymphoma (median age 37 years) was examined for mutations of p53 exons 4–8. One patient had four first‐degree relatives with Hodgkins disease, acute leukemia, and carcinomas, but the family history did not fulfill criteria of LFS. Four patients with Hodgkins disease were diagnosed with metachronous non‐Hodgkins lymphoma as a second malignant neoplasm. No constitutional p53 mutations were detected in any of these patients, implying that outside the clinical spectrum of LFS, constitutional p53 mutations are rare in patients with lymphomas. Am. J. Hematol. 62:144–149, 1999.

Decrease of VEGF-A in myeloid cells attenuates glioma progression and prolongs survival in an experimental glioma model

BACKGROUND Glioblastomas are highly vascularized tumors with a prominent infiltration of macrophages/microglia whose role in promoting glioma growth, invasion, and angiogenesis has not been fully elucidated. METHODS The contribution of myeloid-derived vascular endothelial growth factor (VEGF) to glioma growth was analyzed in vivo in a syngeneic intracranial GL261 glioma model using a Cre/loxP system to knock out the expression of VEGF-A in CD11b + myeloid cells. Changes in angiogenesis-related gene expression profile were analyzed in mutant bone marrow-derived (BMD) macrophages in vitro. Furthermore, we studied the influence of macrophages on GL261 growth, invasiveness, and protein expression profile of angiogenic molecules as well as the paracrine effect of mutant macrophages on angiogenesis in vitro. RESULTS Myeloid cell-restricted VEGF-A deficiency leads to a growth delay of intracranial tumors and prolonged survival. The tumor vasculature in mutant mice was more regular, with increased pericyte coverage. Expression analysis revealed significant downregulation of VEGF-A and slight upregulation of TGFβ-1 in BMD macrophages from mutant mice. Endothelial tube formation was significantly decreased by conditioned media from mutant macrophages. The expression of angiogenesis-related proteins in GL261 glioma cells in co-culture experiments either with wild-type or mutant macrophages remained unchanged, indicating that effects observed in vivo are due to myeloid-derived VEGF-A deficiency. CONCLUSIONS Our results highlight the importance of VEGF derived from tumor-infiltrating myeloid cells for initiating vascularization in gliomas. The combination of antiangiogenic agents with myeloid cell-targeting strategies might provide a new therapeutic approach for glioblastoma patients.

A human Burkitt’s lymphoma cell line carrying t(8;22) and t(14;18) translocations

A combination of chromosomal translocations associated with bcl-2 re-arrangement (t(14;18)) and c-myc re-arrangement (t(8;14), t(8;22), or t(2;8)) is a rare event. We describe the first cell line exhibiting t(14;18) and t(8;22), which will enable us to study the interactions of bcl-2 and c-myc systematically. Cell culture was started with circulating lymphoma cells from the peripheral blood of an adult male Caucasian patient with Burkitt’s lymphoma after the second relapse. The cells grew spontaneously without cytokines, fulfilled all criteria of a cell line and were analysed. An Epstein–Barr virus (EBV) genome-negative cell line (DoGKiT) has been established. RC-banding analysis of the chromosomes showed a complex karyotype with a modal number of 48, XY, dup(1)(q31;q44), t(8;22)(q24;q11), der(10), t(14;18)(q32;q21), add(16)(pter), dup(17)(q12q24), +der(18), +20. The combination of t(8;22)(q24;q11), a variant translocation of Burkitt’s lymphoma and t(14;18)(q32;q21), typical for follicular lymphoma (FL), was confirmed by FISH and SKY-analysis. Surface marker studies of the cell line showed that the cells were positive for CALLA (CD10), CD19, cyCD22, cyCD79a and HLA-DR and negative for TdT, IgM, CD5 and CD23. To our knowledge, this is the first established cell line carrying these two translocations. In contrast to already established cell lines carrying the more common combination of t(8;14)(q24;q32) and t(14;18)(q32;q21) with both IgH alleles being involved in translocations, the cell line DoGKiT carries only one translocated IgH allele. This cell line may serve as an important tool in the study of the combination of the chromosomal translocations t(14;18) and t(8;22) and in molecular genetic studies of transformed FL.