Determination of intermediates, products and cleavage site in the reaction between plasminogen activator inhibitor type-2 and urokinases.

Several specific inhibitors for plasminogen activators have been isolated from various organs and cell lines, those from human placenta and the human monocyte-like cell line U-937 being virtually identical. The reaction between this type of inhibitor, designated as type-2, and high-Mr and low-Mr urokinase-type plasminogen activators was followed by reversed-phase high-performance liquid chromatography and gel electrophoresis. The components, their stable complexes and their dissociation and cleavage products could be clearly identified in both systems. The amino acid sequence of the inhibitor at the cleavage site was determined to be -Met-Thr-Gly-Arg decreases Thr-Gly-His-Gly-. A 35-residue carboxy-terminal fragment was found to be released.

Expression of histamine H1 receptors on cultured histiocytic lymphoma cells.

Histamine H1 receptors were identified in U937 human histiocytic lymphoma cells using a radioligand binding technique with [3H]mepyramine. Reversible high-affinity binding with this ligand was obtained, and specificity of binding for selected H1 agonists and antagonists was demonstrated. Competition binding experiments with mepyramine and histamine yielded results consistent with single-site binding for mepyramine and two-site binding for histamine. Dissociation constants for the high- and low-affinity histamine binding states were 6.8 X 10(-6) and 2.4 X 10(-4) M respectively. The high-affinity state for histamine binding was abolished when the membranes were coincubated with 100 microM guanosine-5'-O-(3-thiotriphosphate) (GTP gamma S). Saturation binding studies yielded an average of 66 fmol/mg protein binding sites (6000 receptors per cell) with a [3H]mepyramine KD of 9.6 nM. When differentiation of these cells was induced by phorbol-myristate-acetate, receptor density increased by 73% to 114 fmol/mg protein. This increase in receptor density was inhibited by actinomycin D and cycloheximide. Exposure of native and differentiated U937 cells to 10(-5) and 10(-4) M histamine for 24 hr resulted in a dose-dependent down-regulation in receptor density. The data indicate that U937 cells may provide a model cell line for the study of histamine receptor gene expression.

Tissue factor-like activity of the human monocytic tumor cell line U937.

Undisrupted cells of the human monocytic tumor cell line U937 have procoagulant activity that is Ca2+ dependent and is not demonstrable in Factor VII or Factor X deficient plasma. Furthermore, U937 cells when incubated with purified human Factor VII in the presence of Ca2+ and then repeatedly washed promoted coagulation of Factor VII deficient plasma in the absence of added tissue factor. Culture with endotoxin increased the procoagulant activity of U937 cells approximately 5-fold. In separate experiments, exposure to lymphokines obtained from phytohemagglutinin-stimulated lymphocytes enhanced the procoagulant activity of U937 cells 4 to 110-fold. Other cell lines (of myeloid and lymphoid origin) tested lacked the procoagulant activity found in U937 cells. These results indicate that the constitutive tissue factor-like activity of U937 cells resembles that of normal activated human monocytes.

Cytophotometric studies on mycosis fungoides and other cutaneous reticuloses.

Feulgen-DNA cytophotometry was carried out in skin imprint preparations of patients with mycosis fungoides, reticulum-cell sarcoma, lymphomatoid papulosis and Sézary's syndrome. These patients proved to have aneuploid and polyploid DNA histograms. In tumour stage of mycosis fungoides a more bimodal distribution of the DNA values was found. Of 79 cases of suspected malignant reticulosis of the skin, 32 showed an abnormal DNA histogram with 5 percent or more tetraploid and hypertetraploid cells. Thirty of these patients developed a malignant skin reticulosis during the 4-year follow-up period. It is concluded that DNA cytophotometry has value as a supplement to routine morphological histopathology in malignant cutaneous reticulosis.

[Trace elements of bone tumors]. / Mikroélementy opukholei kostei.

Due to activation analysis involving the use of neutrons from a nuclear reactor, the concentrations of 11 trace elements: scandium, iron, cobalt, mercury, rubidium, selenium, silver, antimony, chrome, zinc and terbium in intact bone and skeletal tumors were measured. 76 specimens of bioptates and resected material of operations for bone tumors and 10 specimens of normal bone tissue obtained in autopsies of cases of sudden death were examined. The concentrations of trace elements and their dispersion patterns in tumor tissue were found to be significantly higher than those in normal bone tissue. Also, the concentrations of some trace elements in tumor differed significantly from those in normal tissue; moreover, they were found to depend on the type and histogenesis of the neoplasm.

[Feulgencytophotometric DNA distribution patterns of well-differentiated (mature) and undifferentiated (less mature/immature) forms of primary skin-reticulosis]. / Feulgencytophotometrische DNS-Verteilungsmuster bei reifzelligen und unreifzelligen cutanen malignen Retikulosen

33 tissue sections of cases of primary skin-reticulosis showing different degrees of maturity were analysed by means of Feulgen-cytophotometric methods in regard to their DNA-content. The measurements performed disclosed cytophotometric differences of DNA distribution patterns between mature and less mature/immature forms: Mature forms of reticulosis were characterized by predominantly diploid DNA distribution patterns, whereas less mature/immature forms showed a main distribution in the hyperdiploid-hypotetraploid range respectively atypically dispersed aneuploid values with increase of variation and mean DNA-content. Moreover in several cases distribution patterns were seen, which may be regarded as cytophotometric transition forms showing a diploid peak and a higher rate of cells with enhanced DNA-content. Those cases appeared histomorphologically mature with a slight tendency to immaturity.

Sarcoma arising from interdigitating reticulum cells: report of a case, studied with light and electron microscopy, and enzyme- and immunohistochemistry.

The morphological, enzyme- and immunohistochemical features of a sarcoma arising from interdigitating reticulum cells (IDRC) are presented. These cells are normal constituents of the T-dependent region of lymphoid organs, and their function is largely unresolved. The immunohistochemical findings in the present case indicate that neoplastic IDRC are morphologically and phenotypically similar to normal IDRC in lymphoid organs. Functionally however, neoplastic IDRC more closely resemble IDRC in the fetal lymph node and in the thymus, where they are thought to play a role in the final differentiation of immature thymocytes into mature peripheral T-lymphocytes.

Purification and characterization of a plasminogen activator inhibitor from the histiocytic lymphoma cell line U-937.

We report the production, purification, characterization, and partial amino acid sequence of a plasminogen inhibitor (PA-I). The starting material is culture fluid from phorbol myristate 13-acetate-treated U-937 cells and the isolation steps consist of preparative isoelectric focusing followed by affinity chromatography on Cibacron Blue-Sepharose. PA-I migrates as a closely spaced doublet of 47-kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and forms covalent complexes with urokinase and two-chain tissue-type plasminogen activator, displaying second order rate constants of 0.9 X 10(6) M-1 s-1 and 0.2 X 10(6) M-1 s-1, respectively. Upon treatment with 1 M NH4OH, the covalent complexes were hydrolyzed, yielding a 35-kDa inhibitor fragment. A partial amino acid sequence of PA-I showed that it belongs to the antithrombin III family of inhibitors. PA-I is immunologically related to a PA-inhibitor from human placenta. mRNA from phorbol myristate 13-acetate-treated U-937 cells directed, in a rabbit reticulocyte derived cell-free system, the biosynthesis of only one 47-kDa protein that could be immunoprecipitated with anti-PA-I IgG, indicating that the two molecular forms of PA-I are the products of post-translational processing.

Surface marker and histopathologic correlation with long-term survival in advanced large-cell non-Hodgkin's lymphoma.

Since 1974, a group of consecutive adult patients with non-Hodgkin's lymphoma have been prospectively analyzed for tumor-surface membrane-marker phenotype and histopathologic correlation with response to treatment and survival. The results are reported in a subset of 35 patients with advanced (Stages III-IV) large-cell variants, most of whom would be classified by Rappaport criteria as histiocytic. An attempt has been made to define those marker characteristics that will identify long-term survivors in this diverse group who remain in continuous disease-free remission. There were ten patients with complete remissions with intensive treatment. The most common subgroup within the complete responders were patients with cells that were nonexpressive (null) and were classified by Lukes-Collins criteria as the large, noncleaved follicular center cell variant. Currently there are seven patients remaining in complete remission, five of whom have been in continuous disease-free remission for more than two years (total survival 34+-42+ months) following cessation of all treatment. Of those five, four were in the null group and four were classified as large non-cleaved. The actuarial survival curve for all null patients is characterized by a rapid initial decline and a subsequent plateau, which contains four of the long survivors. In contrast, the B-derived group has a more graded decline in survival with time; this curve currently contains the remaining long survivor. Although the overall prognosis of B-derived tumors appears to be superior to that of the null subset, the subgroup with the potential for cure at this point in our study includes patients with both null and B-derived tumors, particularly those classified by Lukes-Collins criteria as the large noncleaved follicular center cell variant.

Diagnostic significance of histiocyte-related markers in malignant histiocytosis and true histiocytic lymphoma.

Interrelationships of immunologic and enzymatic markers of histiocytes have been studied in malignant neoplasms of histiocytic/monocytic origin and in differential diagnostically relevant, large cell non-Hodgkin's lymphomas. Cryostat sections required for demonstrating cell surface antigens by monoclonal antibodies are inadequate for studying cellular detail, enzymatic maturation by alpha-naphthyl acetate esterase (ANAE), and demonstrating the classical cytoplasmic markers of histiocytes like lysozyme, alpha-1-antitrypsin (AT), and alpha-1-antichymotrypsin (ACT). These markers have been compared in gently fixed and vacuum paraffin-embedded material. The reactivity for monoclonal anti-human monocyte 1 (Mo 1) has also been preserved by this method. Malignant histiocytosis (MH) is characterized by a heterogeneous cell population. The mature, ANAE-positive cells with macrophage morphology usually show a diffuse cytoplasmic positivity for AT and ACT. Lysozyme is moderately positive to negative in these cells, but it is more efficient than these markers in revealing smaller cells resembling monocytes by focal positivity in the cytoplasm. The expression of Factor XIIIa (F-XIIIa) is connected with the phagocytic activation of histiocytic cells. F-XIIIa positive cells usually form a minority of the neoplastic population in MH, but the large cytophagocytic marcophages are invariably positive. Reactive macrophages in large cell non-Hodgkin's lymphomas are characterized by a coexpression of ANAE, AT, ACT, lysozyme, F-XIIIa and Mo 1. Typical cases of true histiocytic lymphoma (THL) are made up of a homogeneous population showing the above mature, phagocytizing phenotype. In MH, Mo 1 and ANAE recognize different subpopulations. The reciprocal relation of these markers is an abnormal phenotypic feature. The results presented in this article prove the diagnostic value of ANAE and lysozyme in confirming the histiocytic differentiation of malignant cells. Monoclonal anti-human monocyte 1 is useful for identifying the immature component in MH. Factor XIIIa can be considered a functional marker of mature phagocytic histiocytes and an aid in the diagnosis of THL.

An autopsy case of so-called midline malignant reticulosis followed by extensive dissemination with immunohistochemical evidence for its T cell malignancy.

An autopsy case of malignant midline reticulosis (MMR) is reported. The patient, a 42-year-old Japanese male, died after a clinical course of 22 months. Autopsy revealed extensive infiltration of generalized organs by the tumor cells, suggesting that the disease was highly malignant in nature. Staining with monoclonal antibodies against T-cell surface antigens Leu 4 on frozen sections and UCHL1 on paraffin-embedded sections enabled us to examine the phenotype of the tumor cells with good morphological preservation and to verify the T cell nature of the tumor.

Clinical, ultrastructural immunohistochemical and DNA content analysis of lymphomas having features of interdigitating reticulum cells.

Interdigitating reticulum cells (IRC) are dendritic, nonphagocytic histiocytes found in thymus-dependent areas of lymphoid tissues. We report two cases of large cell lymphoma having features of IRC in patients 13 and 17 years old. In each case the diagnosis was suggested by light and electron microscopic features, positive immunoperoxidase staining for S-100 protein, and additional immunoperoxidase findings. Both patients presented with aggressive lymphomas and were treated with intensive combination chemotherapy. Each patient achieved a complete clinical remission, then rapidly relapsed and died with disseminated disease 3 and 9 months after presentation. Novel findings included strong staining of specimens with an antibody to epithelial membrane antigen, staining of one specimen with peanut agglutinin in the pattern previously described in normal IRC, and a DNA content analysis that showed aneuploid stem cell lines in both patients.

Histiocytic sarcoma (true histiocytic lymphoma): a clinicopathological study of 20 cases.

Large-cell non-Hodgkin's lymphomas (T- and B-immunoblastic, centroblastic and true histiocytic lymphomas) have a heterogeneous clinical course. In the present study the clinical and morphological data of 20 cases of histiocytic sarcoma (true histiocytic lymphoma) are presented. Diagnosis was supported by immunohistochemistry, cytochemistry, rosette assays and/or electron microscopy. Although the follow-up was relatively short (up to 144 months, mean 26 months), the clinical data differed clearly from the series of large-cell non-Hodgkin lymphomas, recorded in the literature. Differences were found in age distribution with a peak in the third decade, in organ involvement showing a preference for skin, gastrointestinal tract and bone, and in response to therapy. In general, histiocytic sarcoma appears to have a more favourable response to therapy and clinical course than the other large-cell lymphomas (T- and B-immunoblastic and centroblastic lymphomas). Moreover, preliminary observations in the group of histiocytic sarcomas suggested that the presence of lysozyme and/or 5-nucleotidase and the absence of alpha 1-antitrypsin in the cytoplasm is associated with a better response to therapy and favourable clinical course.

Histamine H2 receptor activity and histamine metabolism in human U-937 monocyte-like cells and human peripheral monocytes.

Functional and specific histamine H2 receptors were characterized in human peripheral monocytes and in U-937 cells, before and after retinoic acid--induced differentiation into monocyte/macrophage-like cells. The relative potencies of histamine and the H1, H2 receptor agonists and antagonists studied are remarkably similar in U-937 cells and U-937 monocytes. There is no change in histamine concentration and activity of the enzymes forming and degrading histamine during monocytic-like differentiation. The results raise the possibility that histamine H2 receptors might be involved in pathophysiological regulations (proliferation/differentiation and biological function) of normal and leukemic monocytes.

Oncostatin M: a growth regulator produced by differentiated histiocytic lymphoma cells.

A polypeptide termed oncostatin M, which inhibits the replication of A375 melanoma and other human tumor cells, but not normal human fibroblasts, has been isolated from serum-free supernatants of U-937 histiocytic lymphoma cells that have been induced to differentiate into macrophage-like cells following treatment with the phorbol ester phorbol 12-myristate 13-acetate. No such growth inhibitory activity is detected in the supernatant of untreated U-937 cells, indicating that the protein is induced or increased in expression in the phorbol ester-induced differentiated cells. Oncostatin M is stable between pH 2 and 11 and after heating for 1 hr at 56 degrees C but is not stable at 90 degrees C. Purification of oncostatin M has been achieved by gel chromatography and reversed-phase HPLC, using sequentially acetonitrile and n-propanol in the presence of aqueous trifluoroacetic acid. The apparent molecular weight of oncostatin M is approximately 18,000, as determined by gel chromatography, and 28,000, as determined by polyacrylamide gel electrophoresis. The amino-terminal amino acid sequence of the purified polypeptide has been determined. No substantial sequence homology between oncostatin M and other proteins was found, including other tumor cell inhibitory proteins produced by mononuclear cells. Oncostatin M, therefore, appears to represent a distinct cell growth regulator.

Characterization of a novel mouse reticular cell sarcoma M5076 subline resistant to cisplatin.

A novel murine tumor resistant to cis-diamminedichloroplatinum (cisplatin, DDP) was obtained (M5/DDP) after 22 passages in which mice bearing the ovarian reticular cell sarcoma M5076 (M5) were treated with DDP. Although DDP conserved some inhibitory activity on growth of M5/DDP, it was much less effective than on M5. Treatment with DDP did not prolong the survival time of mice with M5/DDP, whereas it markedly prolonged survival of M5-bearing mice. M5 and M5/DDP tumors shared many biological and biochemical features. They were similar histologically, they metastasized reproducibly to the liver and were poorly immunogenic. Their growth rates were comparable; their DNA index, percentage of cells in S phase and intra-cellular glutathione content were also similar. In both tumors, DDP caused an accumulation of cells in S late-G2-M within 24 hr after drug treatment. However, this was efficiently reversed in M5/DDP, whereas it worsened and persisted longer in M5. Cross-resistance was observed between DDP and its analogues carboplatin and iproplatin, but tetraplatin retained marginal activity on M5/DDP tumor. Several alkylating agents tested [L-phenyalanine mustard (L-PAM); cyclophosphamide (CTX); chlorambucil (CLB); 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and dacarbazine (DTIC)] were not totally cross-resistant to DDP, but showed greater activity on M5 than on M5/DDP. Other non-alkylating anti-neoplastic drugs showed a similar degree of activity on M5 and M5/DDP. 5-Aza-2'-deoxycytidine (Aza-d-Cyd) was very effective on both tumors, etoposide (VP-16) and cytosine arabinoside (Ara-C) had no activity and Adriamycin (ADR) was weakly effective.