bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular analysis of chromosome 20q deletions associated with myeloproliferative disorders and myelodysplastic syndromes
Authors: Asimakopoulos FA , White NJ , Nacheva E , Green AR 
Published: October 2019

Abstract
Acquired deletions of the long arm of chromosome 20 are found in several hematologic conditions and particularly in the myeloproliferative disorders and myelodysplastic syndromes. The spectrum of diseases associated with 20q deletions suggests that such deletions may mark the site of a tumor suppressor gene that contributes to the regulation of normal multipotent hematopoietic progenitors. We present here the first detailed molecular analysis of 20q deletions associated with myeloid disorders. Thirty-four microsatellite primer pairs corresponding to loci on 20q have been used to study DNA samples from two cell lines and from highly purified peripheral blood granulocytes obtained from seven patients. In addition, Southern analysis of cell line DNA has been performed using 19 DNA probes that map to 20q. Three conclusions can be drawn from our results. Firstly, molecular heterogeneity of both centromeric and telomeric breakpoints was demonstrated, thus supporting the existence of a tumor suppressor gene on 20q. In addition many of the breakpoints have been mapped to small genetic intervals. Secondly, our results define a commonly deleted region of 16–21 cM which contains ADA, PLC1, TOP1, SEMG1, and PPGB. Several candidate tumor suppressor genes lie outside the common deleted region including SRC, HCK, p107, PTPN1, and CEBP beta. Thirdly, the data allow integration of genetic and physical maps and have refined the map positions of multiple genes. These results will facilitate attempts to identify candidate hematopoietic tumor suppressor genes on 20q.
Expression of the multidrug resistance associated protein and P- glycoprotein in doxorubicin-selected human myeloid leukemia cells
Authors: Slapak CA , Mizunuma N , Kufe DW 
Published: October 2019

Abstract
Drug-resistant sublines of the human U-937 myeloid leukemia cell line were selected in doxorubicin concentrations of 10, 40, and 200 ng/mL (designated U-A10, U-A40, and U-A200, respectively). Northern blot analysis showed overexpression of the multidrug resistance-associated protein (MRP) gene, but not MDR1, in U-A10 cells as compared with parental U-937 cells. Prolonged passage of U-A10 cells in 10 ng/mL of doxorubicin had little effect on MRP RNA levels, but increased MDR1 expression. The U-A40 and U-A200 cells, derived by selection of U-A10 cells, showed high levels of both MRP and MDR1 expression. None of the drug-resistant cell lines showed MRP or MDR1 gene amplification as judged by Southern blot analysis. U-A10 cells exhibited minimal decreased net accumulation of anthracycline, whereas U-A40 and U-A200 cells showed more significantly decreased drug accumulation as compared with U-937 cells. Subcellular anthracycline accumulation in U-937 cells as determined by fluorescence microscopy showed daunorubicin fluorescence predominately in the nucleus. However, the drug-resistant cell lines showed minimal nuclear drug accumulation with marked redistribution of drug into a vesicular compartment. Treatment with sodium azide/2-deoxyglucose, 2,4-dinitrophenol, or monensin, but not verapamil, abolished the vesicular accumulation. These studies in doxorubicin-selected U-937 cells indicate that induction of MRP overexpression occurs before that for the MDR1 gene. In addition, the drug-resistant cells possess an energy-dependent redistribution of anthracyclines into a nonnuclear vesicular compartment.
Pattern and load of spontaneous liver metastasis dependent on host immune status studied with a lacZ transduced lymphoma
Authors: Kruger A , Umansky V , Rocha M , Hacker HJ , Schirrmacher V , von Hoegen P 
Published: October 2019

Abstract
Detection of disseminated leukemia within organ is often very difficult and might lead to underestimation of the metastatic load. Therefore, we transduced the mouse ESb T lymphoma with the bacterial lacZ gene, which allowed us to follow metastasis at the single cell level. Intradermal primary tumor growth of lacZ transduced ESbL cells (L-CI.5s) comprised three phases: an initial expansion phase (day 0 to 9, increase from 0 to 8 mm, tumor diameter), a plateau phase (day 9 to 20, constant diameter of 8 mm and necrosis), and a second expansion phase (day 20 to 30, increase from 8 to 15 mm). Liver metastasis could already be detected at day 3 and maintained at that level until day 23, where exponential expansion started. A distinct mosaic-like metastasis pattern developed, with preferential localization of tumor cells to the periportal areas of the liver in immunocompetent animals. In contrast, in immunocompromised mice, primary tumor growth and metastasis were progressive and metastasis appeared as diffuse or focal/clustered. Healthy animals surviving a tumor cell inoculum of a variant cell ESbL- CI.5) with a reduced metastatic potential carried low levels of possibly dormant tumor cells in the bone marrow. Thus, this study showed that host immunocompetence determines to a large extent kinetics and load of spontaneous liver metastases and even influences the pattern and localization of disseminated lymphoma cells.
The first mutation identified in the thrombomodulin gene in a 45-year- old man presenting with thromboembolic disease
Authors: Ohlin AK , Marlar RA 
Published: October 2019

Abstract
Thrombomodulin (TM) is the anticoagulant endothelial cell membrane- bound protein cofactor in the thrombin-mediated activation of protein C (PC). It has been clearly demonstrated that the anticoagulant and profibrinolytic functions of the PC system are important for the prevention of a thromboembolic disease. Patients with PC, protein S, or PC “‘cofactor”’ deficiency and/or dysfunction develop thromboembolic diseases. However, the molecular abnormality in at least 20% to 30% of thrombophilic patients cannot be identified by hitherto recognized defects. A putative pathologic lesion in the TM gene could be one of several candidates for these prothrombotic mutations. A directed search strategy for deletions, insertions, or point mutations in the TM gene has not been performed. Therefore, in the present study, we have analyzed the entire TM gene, including the promoter region, by polymerase chain reaction-single-strand conformation polymorphism (PCR- SSCP) in normal healthy volunteers and in patients presenting with a thromboembolic disease. We have identified a patient with a thromboembolic disease and a TM point mutation. In a 45-year-old Hispanic man with a documented pulmonary embolism, PCR-SSCP showed an aberrant band pattern and subsequent DNA sequence analysis showed a heterozygous substitution for G1456 to T. This substitution predicts an Asp468 to a Tyr change in the amino acid sequence that is located between the transmembrane domain and the sixth epidermal growth factor- like domain. The Asp468 to Tyr change would probably lead to significant structural changes not allowing the expression of the TM protein or to a conformational change that is not functional.
Identification of two mutations (Arg611Cys and Arg611His) in the A1 loop of von Willebrand factor (vWF) responsible for type 2 von Willebrand disease with decreased platelet-dependent function of vWF [see comments]
Authors: Hilbert L , Gaucher C , Mazurier C 
Published: October 2019

Abstract
We report the identification of von Willebrand factor (vWF) gene mutations within exon 28 occurring in three unrelated families with an infrequent form of type 2 von Willebrand disease (vWD). A C-->T transition and a G-->A transition, both at the codon for arginine 611 of the mature vWF subunit, were found. They result in either a cysteine or an histidine substitution, respectively. Patients were found to be heterozygous for these substitutions and the vWD was transmitted dominantly. These substitutions have been reproduced by in vitro mutagenesis of full-length cDNA of vWF and transiently expressed in Cos- 7 cells. The corresponding recombinant vWFs (rvWF) exhibited decreased expression and a significant decrease in the high molecular weight multimeric forms. In addition, ristocetin- and botrocetin-induced binding of mutated rvWFs to platelets were markedly decreased as compared with that for the wild-type rvWFs. Thus, the structural and functional characterization of both mutated rvWFs confirmed that the two nucleotide substitutions identified at position 611 of the mature subunit of vWF are real mutations. Although they are located in the A1 loop containing most of the type 2B mutations inducing increased affinity of vWF for platelet glycoprotein Ib, they are responsible for abnormal vWF with decreased platelet-dependent function.
Engraftment of bone marrow cells into normal unprepared hosts: effects of 5-fluorouracil and cell cycle status
Authors: Ramshaw HS , Rao SS , Crittenden RB , Peters SO , Weier HU , Quesenberry PJ 
Published: October 2019

Abstract
Bone marrow from animals treated with 5-fluorouracil (5FU) competes equally with normal marrow when assessed in vivo in an irradiated mouse, but shows markedly defective engraftment when transplanted into noncytoablated hosts. Using Southern Blot analysis and a Y-chromosome specific probe, we determined the level of engraftment of male donor cells in the bone marrow, spleen, and thymus of unprepared female hosts. We have confirmed the defective engraftment of marrow harvested 6 days after 5FU (FU-6) and transplanted into unprepared hosts and shown that this defect is transient; by 35 days after 5FU (FU-35), engraftment has returned to levels seen with normal marrow. FU-6 marrow represents an actively cycling population of stem cells, and we hypothesize that the cycle status of the stem cell may relate to its capacity to engraft in the nonirradiated host. Accordingly, we have evaluated the cycle status of engrafting normal and FU-6 marrow into normal hosts using an in vivo hydroxyurea technique. We have shown that those cells engrafting from normal marrow and over 70% of the cells engrafting from FU-6 marrow were quiescent, demonstrating no killing with hydroxyurea. We have also used fluorescent in situ hybridization (FISH) analysis with a Y-chromosome probe and demonstrated that normal and post-5FU engraftment patterns in peripheral blood were similar to those seen in bone marrow, spleen, and thymus. Altogether these data indicate that cells engrafting in normal, unprepared hosts are dormant, and the defect that occurs after 5FU is concomitant with the induction of these cells to transit the cell cycle.
Effects of CD34+ cell selection and perfusion on ex vivo expansion of peripheral blood mononuclear cells
Authors: Sandstrom CE , Bender JG , Papoutsakis ET , Miller WM 
Published: October 2019

Abstract
Ex vivo expansion of peripheral blood mononuclear cells (MNCs), cultured both directly and after selection for CD34+ cells, was compared in static and continuously perfused cultures containing interleukin (IL)-3, IL-6, granulocyte colony-stimulating factor (G- CSF), and stem cell factor (SCF). Cultures inoculated with either MNCs or CD34+ cells produced cells that were remarkably similar after 10 days of culture, as evidence by cell morphology, expression of CD34, CD33, CD15, and CD11b, and the fractions of cells giving rise to colony- forming units granulocyte-monocyte (CFU-GM) and long-term culture- initiating cells (LTC-IC). Static and perfusion cultures gave similar average total cells and CFU-GM expansions for both MNC and CD34+ cell cultures. However, those samples that performed poorly in static culture performed at near-normal levels in perfusion. In addition, perfusion supported higher LTC-IC numbers for both MNC and CD34+ cell cultures. While total cell expansion was about ten times greater in CD34+ cell cultures (approximately 100-fold), CFU-GM expansion (approximately 20-fold) was similar for both MNC and CD34+ cell cultures. The similar distribution of cell types produced in MNC and CD34+ cell cultures allows direct comparison of total and colony- forming cell production. After 15 days in perfusion, MNC cultures produced 1.5-, 2.6-, and 2.1-fold more total cells, CFU-GM, and LTC-IC, respectively, than the same sample selected and cultured as CD34+ cells. Even if the CD34+ selection process was 100% efficient, CFU-GM production would be 1.5-fold greater for MNCs than for CD34+ cells.
Cyclin D1 protein analysis in the diagnosis of mantle cell lymphoma
Authors: de Boer CJ , Schuuring E , Dreef E , Peters G , Bartek J , Kluin PM , van Krieken JH 
Published: October 2019

Abstract
Mantle cell lymphoma (MCL) is a clinicopathologic entity that is difficult to diagnose on histopathologic criteria. Approximately 50% to 70% of MCL contain a t(11;14)(q13;q32) translocation involving the cyclin D1 gene. Irrespective of this rearrangement, almost all MCL show overexpression of the cyclin D1 gene at the mRNA level. Other B-cell non-Hodgkin's lymphomas (NHL) do not show this rearrangement or overexpression of cyclin D1. We developed an immunohistochemical assay to detect overexpression of the cyclin D1 protein on conventional formalin-fixed, paraffin-embedded biopsies using the well-defined monoclonal antibody DCS-6. Expression in tumor cells was compared with expression of cyclin D1 in endothelial cells and fibroblasts. An exclusively nuclear staining pattern was observed. Moreover, expression was directly compared with the expression observed by immunoblot analysis with the same antibody, as well as with mRNA expression and with the occurrence of genomic rearrangements within the BCL-1 locus. Of 13 MCL that were analyzed by immunohistochemistry and immunoblot, 12 showed overexpression with both techniques, whereas no overexpression was observed in 39 other NHL. Of 13 additional MCL studied either by immunohistochemistry or immunoblot, 11 also showed overexpression. Two lymphomas morphologically indistinguishable from MCL but with an aberrant immunophenotype (CD5 negative, CD10 positive) both lacked overexpression of cyclin D1. These results underscore the significance of overexpression of the cyclin D1 protein as a specific marker for MCL. Detection of cyclin D1 overexpression on formalin-fixed, paraffin-embedded tissues using the DCS-6 monoclonal antibody can be applied for routine diagnostic purposes.
Differentiation-associated changes in CD44 isoform expression during normal hematopoiesis and their alteration in chronic myeloid leukemia
Authors: Ghaffari S , Dougherty GJ , Lansdorp PM , Eaves AC , Eaves CJ 
Published: October 2019

Abstract
CD44 is a widely expressed, multifunctional, cell-surface glycoprotein that has been implicated in the regulation of normal hematopoiesis. In addition, expression of particular isoforms of CD44 has been associated with malignant transformation and/or the acquisition of metastatic potential. In this study, we used two recently developed monoclonal anti-CD44 antibodies, one reactive with an epitope shared by many CD44 isoforms and the other with an epitope unique to CD44 isoforms containing amino acids encoded by the alternatively spliced exon v10, to compare the expression of CD44 on primitive hematopoietic cells from the marrow of normal individuals and their neoplastic counterparts present in the peripheral blood of patients with chronic myeloid leukemia (CML). Multiparameter fluorescence-activated cell sorter (FACS) analysis and cell sorting studies showed that CD44 is normally expressed at high to very high levels on both long-term culture-initiating cells (LTC-IC) and granulopoietic colony-forming cells (granulocyte-macrophage colony-forming units [CFU-GM]). In contrast, primitive erythropoietic progenitors (burst-forming units-erythroid [BFU-E]) in normal marrow were more homogeneous in their expression of CD44, and very few (less than 5%) showed the very high levels of CD44 seen on 20% to 25% of LTC-IC and CFU-GM. Antibody staining showed the expression of exon v10-containing CD44 isoforms to be restricted to a small subpopulation (4% to 8%) of morphologically recognizable mature (CD34-) myeloid cells within the light-density fraction of normal marrow cells. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed the presence of two exon v10-containing mRNA species. In CML, a significantly greater proportion of the circulating neoplastic CFU-GM expressed very high levels of CD44, and these CFU-GM were accompanied by an increased number of light density v10+ cells, including some that coexpressed CD34. Nonmalignant hematopoietic progenitors mobilized by prior chemotherapy and growth factor treatment of patients with Hodgkin's disease or acute myeloid leukemia in remission showed no changes in CD44 expression relative to normal marrow progenitors. These results provide evidence of early differentiation-associated changes in CD44 expression during normal hematopoiesis in vivo that may be deregulated in the neoplastic clone of patients with CML.
The kinetics of murine hematopoietic stem cells in vivo in response to prolonged increased mature blood cell production induced by granulocyte colony-stimulating factor
Authors: de Haan G , Dontje B , Engel C , Loeffler M , Nijhof W 
Published: October 2019

Abstract
Because of the complexity of appropriate stem cell assays, little information on the in vivo regulation of murine stem cell biology or stemmatopoiesis is available. It is unknown whether and how in vivo the primitive hematopoietic stem cell compartment is affected during a continued increased production of mature blood cells. In this study, we present data showing that prolonged (3 weeks) administration of granulocyte colony-stimulating factor (G-CSF), which is a major regulator of mature granulocyte production, has a substantial impact on both the size and the location of various stem cell subset pools in mice. We have used the novel cobblestone area forming cell (CAFC) assay to assess the effects of G-CSF on the stem cell compartment (CAFC days 7, 14, 21, and 28). In marrow, in which normally 99% of the total number of stem cells can be found, G-CSF induced a severe depletion of particularly the most primitive stem cells to 5% to 10% of normal values. The response after 7 days of G-CSF treatment was an increased amplification between CAFC day 14 and 7. However, this response occurred at the expense of the number of CAFC day 14. It is likely that the resulting gap of CAFC day 14 cell numbers was subsequently replenished from the more primitive CAFC day 21 and 28 compartments, because these cell numbers remained low during the entire treatment period. In the spleen, the number of stem cells increased, likely caused by a migration from the marrow via the blood, leading to an accumulation in the spleen. The increased number of stem cells in the spleen overcompensated for the loss in the marrow. When total body (marrow and spleen) stem cell numbers were calculated, it appeared that a continued increased production of mature granulocytes resulted in the establishment of a higher, new steady state of the stem cell compartment; most committed stem cells (CAFC day 7) were increased threefold, CAFC day 14 were increased 2.3-fold, CAFC-day 21 were increased 1.8-fold, and the most primitive stem cells evaluated, CAFC day 28, were not different from normal, although now 95% of these cells were located in the spleen. Four weeks after discontinuation of the G-CSF treatment, the stem cell reserve in the spleen had returned to a normal level, whereas stem cell numbers in marrow had recovered to values above normal. This study shows that the primitive stem cell compartment is seriously perturbed during an increased stimulation of the production of mature blood cells.(ABSTRACT TRUNCATED AT 400 WORDS)
Analysis of beta-globin mutations shows stable mixed chimerism in patients with thalassemia after bone marrow transplantation
Authors: Kapelushnik J , Or R , Filon D , Nagler A , Cividalli G , Aker M , Naparstek E , Slavin S , Oppenheim A 
Published: October 2019

Abstract
Beta-thalassemia major (TM) is caused by any of approximately 150 mutations within the beta-globin gene. To establish the degree of chimerism after bone marrow transplantation (BMT), we have performed molecular analysis of beta-globin mutations in 14 patients with TM over a period of 10 years. All patients underwent T cell-depleted allogeneic BMT from HLA-identical related donors, using either in vitro T-cell depletion with CAMPATH 1M and complement or in vivo depletion using CAMPATH 1G in the bone marrow collection bag. To date, at different time periods after BMT, seven patients have some degree of chimerism; six of these patients, all blood transfusion-independent, have donor cells in the range of 70% to 95%, with stable mixed chimerism (MC). The seventh patient has less than 10% donor cells with, surprisingly, only minimal transfusion requirements. The detection of beta-globin gene point mutation, as used here, is a highly specific and sensitive marker for engraftment and MC in patients with thalassemia. In light of its specificity, the method is applicable in all cases of TM, as it is independent of sex and other non-globin-related DNA markers. The high incidence of MC found in our patients may be a consequence of the pre-BMT T-cell depletion. Because MC was associated with transfusion independence, complete eradication of residual host cells for effective treatment of TM and possibly other genetic diseases may prove not to be essential.
Specific involvement of tyrosine 764 of human granulocyte colony- stimulating factor receptor in signal transduction mediated by p145/Shc/GRB2 or p90/GRB2 complexes
Authors: de Koning JP , Schelen AM , Dong F , van Buitenen C , Burgering BM , Bos JL , Lowenberg B , Touw IP 
Published: October 2019

Abstract
Signal transduction from the granulocyte colony-stimulating factor receptor (G-CSF-R) occurs via multiple pathways, one of which involves activation of p21Ras and mitogen-activated protein kinase. The SH2 domain-containing proteins Shc and GRB2 have been implicated in this latter signaling route. We studied the role of these proteins in signal transduction from wild type (WT) G-CSF-R, C-terminal deletion mutants, and tyrosine-to-phenylalanine substitution mutants in transfectants of the mouse pro-B cell line, BAF3. G-CSF stimulation of BAF3 cells expressing WT G-CSF-R induced tyrosine phosphorylation of Shc. Anti-Shc antibodies co-immunoprecipitated tyrosine-phosphorylated 145-kD proteins (p145), whereas GRB2 immunoprecipitates contained phosphorylated Shc, Syp, and proteins of 145 and 90 kD (p90). Neither of these complexes were detected after activation of a C-terminal deletion mutant of G-CSF-R that lacked all four conserved cytoplasmic tyrosine residues. G-CSF induced formation of Syp/GRB2 complexes in all the tyrosine-substitution mutants, suggesting that this association did not depend on the presence of single specific tyrosine residues in G-CSF-R. In contrast, tyrosine 764 of G-CSF-R appeared to be exclusively required for tyrosine phosphorylation of Shc and its association with p145 and GRB2. In addition, tyrosine 764 also specifically mediated binding of GRB2 to p90 without the involvement of Shc. These findings indicate that tyrosine 764 of G-CSF-R has a prominent role in G-CSF signal transduction.