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Three hundred cDNAs containing putatively entire open reading frames (ORFs) for previously undefined genes were obtained from CD34+ hematopoietic stem/progenitor cells (HSPCs), based on EST cataloging, clone sequencing, in silico cloning, and rapid amplification of cDNA ends (RACE). The cDNA sizes ranged from 360 to 3496 bp and their ORFs coded for peptides of 58-752 amino acids. Public database search indicated that 225 cDNAs exhibited sequence similarities to genes identified across a variety of species. Homology analysis led to the recognition of 50 basic structural motifs/domains among these cDNAs. Genomic exon-intron organization could be established in 243 genes by integration of cDNA data with genome sequence information. Interestingly, a new gene named as HSPC070 on 3p was found to share a sequence of 105bp in 3Ј UTR with RAF gene in reversed transcription orientation. Chromosomal localizations were obtained using electronic mapping for 192 genes and with radiation hybrid (RH) for 38 genes. Macroarray technique was applied to screen the gene expression patterns in five hematopoietic cell lines (NB4, HL60, U937, K562, and Jurkat) and a number of genes with differential expression were found. The resource work has provided a wide range of information useful not only for expression genomics and annotation of genomic DNA sequence, but also for further research on the function of genes involved in hematopoietic development and differentiation.

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Several phosphate transporters (PTs) that belong to the Pht2 family have been released in bioinformatics databases, but only a few members of this family have been functionally characterized. In this study, we found that wheat TaPHT2;1 shared high identity with a subset of Pht2 in diverse plants. Expression analysis revealed that TaPHT2;1 was strongly expressed in the leaves, was up-regulated by low Pi stress, and exhibited a circadian rhythmic expression pattern. TaPHT2;1-green fluorescent protein fusions in the leaves of tobacco and wheat were specifically detected in the chloroplast envelop. TaPHT2;1 complemented the Pi transporter activities in a yeast mutant with a defect in Pi uptake. Knockdown expression of TaPHT2;1 significantly reduced Pi concentration in the chloroplast under sufficient (2 mM Pi) and deficient Pi (100 μM Pi) conditions, suggesting that TaPHT2;1 is crucial in the mediation of Pi translocation from the cytosol to the chloroplast. The down-regulated expression of TaPHT2;1 resulted in reduced photosynthetic capacities, total P contents, and accumulated P amounts in plants under sufficient and deficient Pi conditions, eventually leading to worse plant growth phenotypes. The TaPHT2;1 knockdown plants exhibited pronounced decrease in accumulated phosphorus in sufficient and deficient Pi conditions, suggesting that TaPHT2;1 is an important factor to associate with a distinct P signaling that up-regulates other PT members to control Pi acquisition and translocation within plants. Therefore, TaPHT2;1 is a key member of the Pht2 family involved in Pi translocation, and that it can function in the improvement of phosphorus usage efficiency in wheat.

Purpose: To explore the preventive and therapeutic antitumor effects of nicotine-treated immature dendritic cells (imDC). Experimental Design: First, bone marrow^derived imDCs were stimulated with nicotine in vitro, and nicotinic acetylcholine receptor, costimulator molecules, chemokine receptor, and endocytosis ability of imDCs were detected by flow cytometry. Second, the DC-dependent antigen-specific T-cell proliferation, CTL priming, and interleukin-12 secretion were determined by flow cytometry, enzyme-linked immunospot assay, and ELISA, respectively. Finally, preventive and therapeutic antitumor effects of such imDCs were determined by i.p. transfer against tumor challenge or implantation in mice. Results: Nicotine could up-regulate expression of nicotinic acetylcholine receptor, costimulatory molecules, such as CD80, CD86, and CD40, adhesion molecule CD11b, and chemokine receptor CCR7 and enhance endocytosis ability of imDCs. In addition, nicotine could promote imDCdependent CTL priming and interleukin-12 secretion in vitro. Most importantly, systemic transfer of ex vivo nicotine-stimulated imDCs could reveal preventive and therapeutic effect on tumor development. Conclusions: Ex vivo nicotine stimulation can significantly improve the efficacy of imDCs for adaptive therapy of cancer and nicotine-treated imDCs may be considered as a potential candidate for preventive and therapeutic tumor vaccination.Numerous approaches for antigen-specific active immunotherapy have been developed relying on random encounter of the vaccine with host dendritic cells (DC; refs. 1, 2). A lack of encounter of the vaccine antigen with DCs might result in the absence of an immune response, or alternatively, an inappropriate encounter might lead to silencing of the immune response (3). Therefore, studies are urgently needed based on ex vivo -generated autologous DCs loaded with antigen under controlled conditions. Some reports have shown that DCs loaded with antigens could induce therapeutic and protective antitumor immunity in mice (3, 4). But, the efficacy of therapeutic vaccination has been questioned recently (5). In the last decade, several groups have documents that nicotine has positive effects in treatment of neurodegenerative diseases, ulcerative colitis and, Tourette syndrome (6 -8). Although the expression of nicotinic acetylcholine receptor (nAChR) has been shown in many types of nonneuronal cells, such as DCs, epithelial cells, and endothelial cells (9), the effect of nicotine on immune cells is incompletely characterized. Some investigators showed that nicotine could promote immune cell activation (10 -12), whereas others indicated that nicotine might have immunosuppressive effects on macrophages and DCs (13 -15). In the present study, we first characterized that nicotine has stimulatory effects on immature DCs (imDC) and second showed that nicotine stimulation could enhance T-cell priming ability of imDCs. Finally and most importantly, we revealed the in vivo preventive and therapeutic effect on tumor devel...

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Acute promyelocytic leukemia (APL) is characterized by typical morphological manifestation, t(15;17) translocation and active response to all-trans retinoic acid (ATRA) in the great majority of patients. However, a subset of APL cases may present atypical phenotypic, cytogenetic or molecular features at different stages of the disease. The biological and clinical significance of these features sometimes remains obscure. In this study, 284 APL patients were cytogenetically analyzed and precise diagnosis was performed according to the molecular cytogenetic results. Twenty-six APL patients were identified as having additional, complex and/or variant chromosomal abnormalities at diagnosis or at relapse, 16 of them being further analyzed using fluorescence in situ hybridization (FISH) or chromosome painting (CP). Interestingly, some of these chromosomal aberrations were found to be associated with atypical morphology and/or drug response, indicating a genotype-phenotype correlation. Analysis of the complex karyotype may also allow a better understanding of the levels of cellular origin of the leukemogenesis. Examination of the remission induction and survival data showed that the presence of the additional/complex chromosome abnormalities was related to the prognosis in both primarily diagnosed and relapsed patients in this series. Leukemia (2001) 15, 1359-1368.