Search

Summary. Inositol hexaphosphate (IP6 ), a naturally polyphosphorylated carbohydrate, has been reported to have significant in vivo and in vitr o anticancer activity against numerous tumours, such as colon, prostate, breast, liver and rhabdomyosarcomas. To confirm this activity in haematological malignancies and to characterize some of the mechanisms of IP6 action, we analysed its effects on human leukaemic cell lines and fresh chronic myelogenous leukaemia (CML) progenitor cells using a combined cellular and molecular approach. IP6 had a dose-dependent cytotoxic effect on all of the evaluated cell lines, with accumulation in the G2 M phase in two out of five cell lines tested. At the molecular level, cDNA microarray analysis after IP6 exposure showed an extensive downmodulation of genes involved in transcription and cell cycle regulation and a coherent upregulation of cell cycle inhibitors. Furthermore, IP6 treatment of fresh leukaemic samples of bone marrow CD34+ CML progenitor cells significantly inhibited granulocyte–macrophage colony-forming unit (CFU-GM) formation (P = 0·0062) in comparison to normal bone marrow specimens, which were not affected. No differentiating effect on HL60 cells was observed. Taken together, our results confirm the antiproliferative activity of IP6 and suggest that it may have a specific antitumour effect also in chronic myeloid leukaemias, via active gene modulation. [ABSTRACT FROM AUTHOR]

We report a method of purifying, characterizing and expanding endothelial cells (ECs) derived from CD133[sup +] bone marrow cells, a subset of CD34[sup +] haematopoietic progenitors. Isolated using immunomagnetic sorting (mean purity 90 ± 5%), the CD133[sup +] bone marrow cells were grown on fibronectin-coated flasks in M199 medium supplemented with fetal bovine serum (FBS), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and insulin growth factor (IGF-1). The CD133[sup +] fraction contained 95 ± 4% CD34[sup +] cells, 3 ± 2% cells expressing VEGF receptor (VEGFR-2/KDR), but did not express von Willebrand factor (VWF), VE-cadherin, P1H12 or TE-7. After 3 weeks of culture, the cells formed a monolayer with a typical EC morphology and expanded 11 ± 5 times. The cells were further purified using Ulex europaeus agglutinin-1 (UEA-1)-fluorescein isothiocyanate (FITC) and anti-FITC microbeads, and expanded with VEGF for a further 3 weeks. All of the cells were CD45[sup -] and CD14[sup -], and expressed several endothelial markers (UEA-1, VWF, P1H12, CD105, E-selectin, VCAM-1 and VE-cadherin) and typical Weibel–Palade bodies. They had a high proliferative potential (up to a 2400-fold increase in cell number after 3 weeks of culture) and the capacity to modulate cell surface antigens upon stimulation with inflammatory cytokines. Purified ECs were also co-cultivated with CD34[sup +] cells, in parallel with a purified fibroblastic cell monolayer. CD34[sup +] cells (10 × 10[sup 5]) gave rise to 17 951 ± 2422 CFU-GM colonies when grown on endothelial cells, and to 12 928 ± 4415 CFU-GM colonies on fibroblast monolayers. The ECs also supported erythroid blast-forming unit (BFU-E) colonies better. These results suggest that bone marrow CD133[sup +] progenitor cells can give rise to highly purified ECs, which have a high proliferative capacity, can be activated by inflammatory cytokines and are super... [ABSTRACT FROM AUTHOR]

Examines the ultrastructural morphology of CD34[sup+] hematopoietic stem cells from different sources in the human body. Analysis on the endogenous myelo-peroxidase activity; Amount of aptotic cells within samples from various sources; Use of transmission electron microscopy with cytochemical method.

Abstract: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has a large number of biological effects, including skin, cardiovascular, neurologic diseases, diabetes, infertility, cancers and immunotoxicity. We analysed the in vitro TCDD effects on human CD34+ cells and tested the gene expression modulation by means of microarray analyses before and after TCDD exposure. We identified 257 differentially modulated probe sets, identifying 221 well characterized genes. A large part of these resulted associated to cell adhesion and/or angiogenesis and to transcription regulation. Synaptic transmission and visual perception functions, with the particular involvement of the GABAergic pathway were also significantly modulated. Numerous transcripts involved in cell cycle or cell proliferation, immune response, signal transduction, ion channel activity or calcium ion binding, tissue development and differentiation, female or male fertility or in several metabolic pathways were also affected after dioxin exposure. The transcriptional profile induced by TCDD treatment on human CD34+ cells strikingly reproduces the clinical and biological effects observed in individuals exposed to dioxin and in biological experimental systems. Our data support a role of dioxin in the neoplastic transformation of hemopoietic stem cells and in immune modulation processes after in vivo exposure, as indicated by the epidemiologic data in dioxin accidentally exposed populations, providing a molecular basis for it. In addition, TCDD alters genes associated to glucidic and lipidic metabolisms, to GABAergic transmission or involved in male and female fertility, thus providing a possible explanation of the diabetogenic, dyslipidemic, neurologic and fertility effects induced by TCDD in vivo exposure. [Copyright &y& Elsevier]

The clinical and biochemical features of an acute and initial Wegener's granulomatosis case were analysed in a young woman. A multifactorial aspects are evident. A chronic inflammation of the superior respiratory tract has been observed. Staphylococcus aureus has been isolated. An oligoclonal component constituted of high levels of anti-PR3 autoantibodies was detected: initial autoreactive B cell clone activation is probable. The chronological link with postpartum is present: our study excluded foetal microchimerism; the hormonal state can be a trigger factor. Serical IL-17 was negative.