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Promyelocytic Leukemia (promyelocytic + leukemia)
Kinds of Promyelocytic Leukemia Terms modified by Promyelocytic Leukemia Selected AbstractsDetection of the STAT5B,RARA fusion transcript in acute promyelocytic leukemia with the normal chromosome 17 on G-bandingEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2008Manabu Kusakabe Abstract Acute promyelocytic leukemia (APL) is characterized by chromosomal rearrangements of 17q21, leading to fusion of the gene-encoding retinoic acid receptor alpha (RARA) with a number of alternative partner genes. Signal transducer and activator of transcription 5 beta (STAT5B) is one of the alternative partners. We report a rare case of APL with STAT5B,RARA fusion transcript and the normal chromosome 17 on G-banding. Administration of all trans -retinoic acid improved disseminated intravascular coagulation without decrease of the leukemia cells in his peripheral blood and bone marrow. The molecular mechanism of fusion between STAT5B and RARA by chromosomal rearrangement is discussed based on the data from genome database. Clinical characteristics of APL with STAT5B,RARA are also discussed. [source] Genomewide array-based comparative genomic hybridization analysis of acute promyelocytic leukemiaGENES, CHROMOSOMES AND CANCER, Issue 4 2006Sivasundaram Karnan Acute promyelocytic leukemia (APL) is typically associated with the t(15;17) that generates the PML,RARA fusion protein. Animal models have shown that although the fusion protein is necessary, it is insufficient for the development of APL, implying that additional mechanisms are responsible for full-blown leukemia. The mutation of specific genes has been implicated in leukemogenesis; however, alterations in gene copy number have not been well investigated. Here, we applied the genomewide array-comparative genomic hybridization technique to 30 APL clinical samples and 2 APL cell lines. It was found that (1) approximately half the clinical samples (14 of 30 APL cases) had no detectable chromosomal imbalances; and (2) the remaining 16 cases, including the cell lines, exhibited recurrent chromosomal imbalances, such as loss of 1p36, 2p11, 16p, and 17p, and gain of 8p, 8q, and 13q. These results suggest that chromosomal imbalances are largely absent in APL, although some nonrandom chromosomal imbalances could be linked to the development of APL in a limited number of cases. © 2006 Wiley-Liss, Inc. [source] PRDX4, a member of the peroxiredoxin family, is fused to AML1 (RUNX1) in an acute myeloid leukemia patient with a t(X;21)(p22;q22)GENES, CHROMOSOMES AND CANCER, Issue 4 2004Yanming Zhang The AML1 gene (also known as RUNX1) at 21q22 codes for core binding factor (CBF) ,, which forms a heterodimer with CBF , that acts as a transcriptional activating factor. CBF is a critical regulator in the generation and differentiation of definitive hematopoietic stem cells and is frequently disrupted in leukemia through chromosome translocations. We cloned a novel AML1 partner gene, PRDX4, in an X;21 translocation in a 74-year-old male patient diagnosed with acute myeloid leukemia,M2. Chromosome analysis detected a t(X;21)(p22;q22) as the sole abnormality in bone marrow samples. The involvement of AML1 was confirmed by fluorescence in situ hybridization studies. Using 3, RACE-PCR, we cloned a fusion between exon 5 of AML1 and exon 2 of PRDX4. RT-PCR confirmed the fusion and detected another fusion between exon 6 of AML1 and exon 2 of PRDX4, indicating alternative splicing of exon 6 of AML1 in the fusion transcripts. PRDX4 is one of six peroxiredoxin-family genes that are highly conserved in eukaryotes and prokaryotes and are ubiquitously expressed. Peroxiredoxin genes exhibit thioredoxin-dependent peroxidase activity and have been implicated in a number of other cellular functions such as cell proliferation and differentiation. PRDX4 plays a regulatory role in the activation of the transcription factor NF-,B and is significantly down-regulated in acute promyelocytic leukemia. This is the first example of antioxidant enzyme involvement in a chromosome translocation in leukemia. © 2004 Wiley-Liss, Inc. [source] Arsenic derivatives in hematologic malignancies: a role beyond acute promyelocytic leukemia?HEMATOLOGICAL ONCOLOGY, Issue 4 2006Srdan Verstovsek Abstract The importance of arsenic trioxide (As2O3) has been underscored over the last decade due to its efficacy against acute promyelocytic leukemia (APL), a disease in which this agent has been associated with complete hematologic and molecular remission rates of 87% and 83%, respectively. The different molecular mechanisms of action of As2O3 suggest its applicability in hematologic malignancies other than APL. However, responses obtained thus far have consisted of improvements in signs and symptoms without the elimination of a given disease. Toxicities derived from As2O3 are significant but manageable and reversible. However, the risk/benefit ratio of As2O3 in hematologic malignancies other than APL is still unclear. The development of new generations of orally bioavailable inorganic, as well as new organic, arsenic compounds with improved toxicity profiles may bolster the therapeutic application of arsenic derivatives in hematologic malignancies such as leukemia, multiple myeloma and myelodysplastic syndromes. Copyright © 2006 John Wiley & Sons, Ltd. [source] An efficient therapeutic approach to patients with acute promyelocytic leukemia using a combination of arsenic trioxide with low-dose all-trans retinoic acidHEMATOLOGICAL ONCOLOGY, Issue 2 2004Guanjun Wang Abstract The use of arsenic trioxide (As2O3, ATO) combined with all-trans retinoic acid (ATRA) has recently been reported to induce remission in patients with acute promyelocytic leukemia (APL). However, its efficiency remains inconclusive mainly due to the small number of the available cases. In this study, therefore, we present a clinical study using a combination of ATO with low-dose ATRA (LD-ATRA) to treat 108 APL patients (80 newly diagnosed patients, 28 relapsed patients). Therapeutic outcomes using the ATO/LD-ATRA approach were compared with those of APL patients treated either with ATO alone (65 patients) or ATRA alone (51 patients). The results showed that the ATO/LD-ATRA approach provided significantly better therapeutic outcomes as compared to either ATO or ATRA alone, as evidenced by lower mortality, a higher CR rate and a reduced period to CR. In addition, the toxic side-effects have been no worse with the combined ATO/LD-ATRA treatment than with either ATO or ATRO alone and in some cases have been reduced. These data suggest that the ATO/LD-ATRA regimen is superior to either regimen given alone to patients with APL. Copyright © 2004 John Wiley & Sons, Ltd. [source] PLC-,2 monitors the drug-induced release of differentiation blockade in tumoral myeloid precursorsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2006Federica Brugnoli Abstract The differentiation therapy in treatment of acute promyelocytic leukemia (APL), based on the administration of all-trans retinoic acid (ATRA), is currently flanked with the use of As2O3, a safe and effective agent for patients showing a resistance to ATRA treatment. A synergy between ATRA and As2O3 was also reported in inducing granulocytic differentiation of APL-derived cells. We have demonstrated that phospholipase C-,2 (PLC-,2), highly expressed in neutrophils and nearly absent in tumoral promyelocytes, largely increases during ATRA treatment of APL-derived cells and strongly correlates with the responsiveness of APL patients to ATRA-based differentiating therapies. Here we report that, in APL-derived cells, low doses of As2O3 induce a slight increase of PLC-,2 together with a moderate maturation, and cooperate with ATRA to provoke a significant increase of PLC-,2 expression. Remarkably, the amounts of PLC-,2 draw a parallel with the differentiation levels reached by both ATRA-responsive and -resistant cells treated with ATRA/As2O3 combinations. PLC-,2 is not necessary for the progression of tumoral promyelocytes along the granulocytic lineage and is unable to overcome the differentiation block or to potentiate the agonist-induced maturation. On the other hand, since its expression closely correlates with the differentiation level reached by APL-derived cells induced to maturate by drugs presently employed in APL therapies, PLC-,2 represents indeed a specific marker to test the ability of differentiation agents to induce the release of the maturation blockade of tumoral myeloid precursors. J. Cell. Biochem. 98: 160,173, 2006. © 2006 Wiley-Liss, Inc. [source] SP100B is a repressor of gene expressionJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2005Kent W. Wilcox Abstract Mammalian cell nuclei exhibit discrete sites where specific proteins characteristically localize. PML nuclear bodies (PML NBs) (nuclear domain 10s (ND10s)) are the primary localization site for the promyelocytic leukemia (PML) protein and the SP100 autoantigen. The observations that some PML and SP100 isoforms can function as transcriptional regulators, that both the size and number of PML bodies increase in response to interferon treatment, and that many mammalian viruses encode proteins that mediate disruption of PML bodies suggest that these sites suppress viral infection, perhaps by repressing viral gene expression. We hypothesized that a component of PML NBs functions as a repressor of gene expression. To test this hypothesis, we characterized the effect of PML or SP100 isoforms on expression of transfected reporter genes. PML-I, PML-VI, and SP100A did not repress reporter gene expression. In contrast, SP100B repressed reporter gene expression, especially under conditions in which the reporter gene expression was elevated by a viral transactivator or addition of trichostatin A to the culture medium. The SP100B DNA binding domain was required for repression. SP100B had no detectable effect on the amount, methylation pattern, or topological form of plasmid DNA in the nuclei of transfected cells. The demonstrated repressive activity of SP100B supports the hypothesis that SP100B is a component of an innate immune response that represses expression of ectopic DNA. © 2005 Wiley-Liss, Inc. [source] PML/RAR, fusion protein mediates the unique sensitivity to arsenic cytotoxicity in acute promyelocytic leukemia cells: Mechanisms involve the impairment of cAMP signaling and the aberrant regulation of NADPH oxidase,JOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2008Lingna Li Acute promyelocytic leukemia (APL) cells are characterized by PML/RAR, fusion protein, high responsiveness to arsenic trioxide (ATO)-induced cytotoxicity and an abundant generation of reactive oxygen species (ROS). In this study we investigated the association among these three features in APL-derived NB4 cells. We found that NADPH oxidase-derived ROS generation was more abundant in NB4 cells compared with monocytic leukemia U937 cells. By using PR9, a sub-line of U937 stably transduced with the inducible PML/RAR, expression vectors, we attributed disparities on ROS generation and ATO sensitivity to the occurrence of PML/RAR, fusion protein, since PML/RAR,-expressing cells appeared higher NADPH oxidase activity, higher ROS level and higher sensitivity to ATO. On the other hand, the basal intensity of cAMP signaling pathway was compared between NB4 and U937 as well as between PR9 cells with or without PML/RAR,, demonstrating that PML/RAR,-expressing cells had an impaired cAMP signaling pathway which relieved its inhibitory effect on NADPH oxidase derived ROS generation. In summary, the present study demonstrated the correlation of PML/RAR, with cAMP signaling pathway, NADPH oxidase and ROS generation in APL cells. PML/RAR, that bestows NB4 cells various pathological features, paradoxically also endows these cells with the basis for susceptibility to ATO-induced cytotoxcity. J. Cell. Physiol. 217: 486,493, 2008. © 2008 Wiley-Liss, Inc. [source] Biodistribution characteristics of all- trans retinoic acid incorporated in liposomes and polymeric micelles following intravenous administrationJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 12 2005Shigeru Kawakami Abstract The aim of this study was to investigate the biodistribution characteristics of all- trans retinoic acid (ATRA) incorporated in liposomes and polymeric micelles following intravenous administration. [3H] ATRA were incorporated in distearoylphosphatidylcholine (DSPC)/cholesterol (6:4) liposomes. Two types of block copolymers, poly (ethylene glycol)-b-poly-(aspartic acid) derivatives with benzyl (Bz-75) groups, were synthesized to prepare the polymeric micelles for [3H]ATRA incorporation. ATRA were dissolved in mouse serum to analyze their inherent distribution. After intravenous administration, the blood concentration of [3H] ATRA in liposomes and polymeric micelles (Bz-75) was higher than that of inherent [3H]ATRA, suggesting that liposomes and polymeric micelles (Bz-75) control the distribution of ATRA. Pharmacokinetic analysis demonstrated that [3H]ATRA incorporated in polymeric micelles (Bz-75) exhibit the largest AUCblood and lowest hepatic clearance of ATRA, suggesting that polymeric micelles (Bz-75) are an effective ATRA carrier system for acute promyelocytic leukemia (APL) therapy. These results have potential implications for the design of ATRA carriers for APL patients. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:2606,2615, 2005 [source] The risk of thrombosis in patients with acute leukemia: occurrence of thrombosis at diagnosis and during treatmentJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 9 2005V. DE STEFANO Summary.,Background:,Thromboembolism can occur during acute leukemia, especially acute lymphoid leukemia (ALL) treated with l -asparaginase. Yet, most reports are anecdotical and scarce data are available on the risk of thrombosis in acute myeloid leukemia (AML). Objectives:,To evaluate the risk of thrombosis in patients with acute leukemia. Patients and methods:,Three-hundred and seventy-nine consecutive adult patients with newly diagnosed acute leukemia were recruited in an observational cohort study conducted from January 1994 to December 2003. Diagnosis was ALL in 69 patients, acute promyelocytic leukemia (APL; FAB subtype M3) in 31, and non-M3 AML in 279. All first or recurrent symptomatic thromboembolic events objectively diagnosed were recorded. Results:,Twenty-four patients of the overall 379 (6.3%; 95% CI 4.1%,9.2%) had a first thrombosis, venous in 80% of the cases and arterial in 20%. At diagnosis, thrombosis was a presenting manifestation in 13 cases (3.4% of the whole cohort): 1.4% in ALL, 9.6% in APL, and 3.2% in non-M3 AML patients. Follow-up was carried out on 343 patients without thrombosis at diagnosis and further 11 thrombotic events (3.2%) were recorded. At 6 months from diagnosis, the cumulative incidence of thrombosis was 10.6% in ALL, 8.4% in APL, and 1.7% in non-M3 AML patients. The patients who received l -asparaginase had a 4.9-fold increased risk of thrombosis in comparison with those who did not (95% CI 1.5,16.0). The fatality rate due to thrombosis was 0.8%. Conclusions:,In patients with acute leukemia, the risk of thrombosis is not negligible. Thombosis can be a presenting symptom at diagnosis in a significant portion of cases with APL (9.6%) and non-M3 AML (3.2%); a similar rate of thrombosis can occur during the subsequent course of the disease. The incidence of symptomatic thrombosis at diagnosis is relatively low in ALL patients (1.4%), but is significantly increased by further treatment up to 10.6%. Strategies of antithrombotic prophylaxis should be investigated in this setting. [source] Renal cell carcinoma and acute promyelocytic leukemia: A nonrandom association?,AMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2010Ritesh Parajuli No abstract is available for this article. [source] Erratum: "Secondary clonal cytogenetic abnormalities following successful treatment of acute promyelocytic leukemia" by Batzios et al.AMERICAN JOURNAL OF HEMATOLOGY, Issue 7 2010Am J Hematol 84:715-71, DOI number 2152 No abstract is available for this article. [source] Secondary clonal cytogenetic abnormalities following successful treatment of acute promyelocytic leukemia,AMERICAN JOURNAL OF HEMATOLOGY, Issue 11 2009Crisoula Batzios To identify patients who developed secondary clonal cytogenetic aberrations (CCA) following therapy for acute promyelocytic leukemia (APL), we retrospectively analyzed cytogenetic results from 123 patients diagnosed with APL between 1995 and 2007, who had ongoing cytogenetic analysis undertaken in our laboratory. During follow-up for APL we identified 12 patients (9.8%) who developed CCA, not detected at diagnosis of APL and unrelated to their original APL karyotype. All patients had received all-trans retinoic acid (ATRA) and chemotherapy and were in complete remission for APL when secondary CCA were identified. The median latency period between diagnosis of APL and emergence of secondary CCA was 27.5 months (range: 2,54 months). To date, four patients with CCA have been diagnosed with therapy-related myelodysplastic syndrome (t-MDS)/acute myeloid leukemia (t-AML), giving a median t-MDS/AML free survival of 78 months, with follow-up ranging between 20 and 136 months from APL diagnosis. Three patients have died: two patients died of t-AML and another developed relapsed APL with persistence of his secondary clone but no diagnosis of t-MDS/AML and died from transplant-related complications. Two patients are alive with t-MDS. Seven patients with CCA are alive with no morphological evidence of MDS at the time of their last known follow-up; thus median survival has not been reached. The appearance of these abnormalities in the absence of morphological evidence of MDS in the majority of patients is unusual, and highlights the importance of continued cytogenetic follow-up in these patients. Am. J. Hematol., 2009. © 2009 Wiley-Liss, Inc. [source] Two cases of monocular visual loss during oral arsenic trioxide therapy of acute promyelocytic leukemia,AMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2009Wing-Yan Au No abstract is available for this article. [source] Fournier's gangrene and scrotal ulcerations during all-trans-retinoic acid therapy for acute promyelocytic leukemiaPEDIATRIC BLOOD & CANCER, Issue 2 2008Rahul Naithani MD Abstract Scrotal ulcers are a rare manifestation in patients with acute promyelocytic leukemia. Fournier's gangrene (FG) is even rarer. We describe three adolescents and young adults who developed scrotal ulcerations during induction with all-trans-retinoic acid. One patient developed FG. These lesions are predominantly seen in Asian population. A good outcome with supportive management occurred in all the cases. Pediatr Blood Cancer 2008;51:303,304. © 2008 Wiley-Liss, Inc. [source] Pseudotumor cerebri manifesting as a symptom of acute promyelocytic leukemiaPEDIATRICS INTERNATIONAL, Issue 1 2000Shigeko Saitoh No abstract is available for this article. [source] Acute promyelocytic leukemia developing in untreated essential thrombocythemiaAMERICAN JOURNAL OF HEMATOLOGY, Issue 2 2002Naoaki Sato Abstract We describe a patient with untreated essential thrombocythemia (ET) who developed microgranular variant of acute promyelocytic leukemia, 9 years after the initial diagnosis of ET. He achieved complete remission (CR) but relapsed 11 months later. After achieving the second CR, he received peripheral stem cell transplantation from his HLA complete-matched sibling. Five months after the transplantation, he relapsed again with meningeal infiltration of leukemic cells. In this paper, we review cases of promyelocytic transformation of myeloproliferative diseases (MPD) other than chronic myeloid leukemia (CML). To our knowledge, this is the first case of promyelocytic transformation of Philadelphia chromosome negative untreated ET, in whom both t(15;17) and PML-RAR, fusion were proven. Am. J. Hematol. 71:114,116, 2002. © 2002 Wiley-Liss, Inc. [source] Toxicity of a trivalent organic arsenic compound, dimethylarsinous glutathione in a rat liver cell line (TRL 1215)BRITISH JOURNAL OF PHARMACOLOGY, Issue 7 2006T Sakurai Background and purpose: Although inorganic arsenite (AsIII) is toxic in humans, it has recently emerged as an effective chemotherapeutic agent for acute promyelocytic leukemia (APL). In humans and most animals, AsIII is enzymatically methylated in the liver to weakly toxic dimethylarsinic acid (DMAsV) that is a major pentavalent methylarsenic metabolite. Recent reports have indicated that trivalent methylarsenicals are produced through methylation of AsIII and participate in arsenic poisoning. Trivalent methylarsenicals may be generated as arsenical,glutathione conjugates, such as dimethylarsinous glutathione (DMAsIIIG), during the methylation process. However, less information is available on the cytotoxicity of DMAsIIIG. Experimental approach: We synthesized and purified DMAsIIIG using high performance TLC (HPTLC) methods and measured its cytotoxicity in rat liver cell line (TRL 1215 cells). Key results: DMAsIIIG was highly cytotoxic in TRL 1215 cells with a LC50 of 160 nM. We also found that DMAsIIIG molecule itself was not transported efficiently into the cells and was not cytotoxic; however it readily became strongly cytotoxic by dissociating into trivalent dimethylarsenicals and glutathione (GSH). The addition of GSH in micromolar physiological concentrations prevented the breakdown of DMAsIIIG, and the DMAsIIIG-induced cytotoxicity. Physiological concentrations of normal human serum (HS), human serum albumin (HSA), and human red blood cells (HRBC) also reduced both the cytotoxicity and cellular arsenic uptake induced by exposure to DMAsIIIG. Conclusions and implications: These findings suggest that the significant cytotoxicity induced by DMAsIIIG may not be seen in healthy humans, even if DMAsIIIG is formed in the body from AsIII. British Journal of Pharmacology (2006) 149, 888,897. doi:10.1038/sj.bjp.0706899 [source] Acute pulmonary failure during remission induction chemotherapy in adults with acute myeloid leukemia or high-risk myelodysplastic syndromeCANCER, Issue 1 2010Ali Al Ameri MD Abstract BACKGROUND: Acute pulmonary failure during remission induction therapy is a serious complication in patients with acute myeloid leukemia (AML). To the authors' knowledge, the course and prognosis of such patients is not well known. METHODS: A total of 1541 patients referred for remission induction chemotherapy of AML or high-risk myelodysplastic syndrome were retrospectively reviewed. RESULTS: A total of 120 (8%) patients developed acute pulmonary failure within 2 weeks of the initiation of chemotherapy; 87 of these patients (73%) died during remission induction, whereas 17 (14%) achieved a complete response. The median survival among the 120 patients with early acute pulmonary failure was 3 weeks. Predictive factors for the development of early acute pulmonary failure by multivariate analysis were: male sex (P = .00038), acute promyelocytic leukemia (P = .00003), poor performance status (P = .001), lung infiltrates at diagnosis (P = .000001), and increased creatinine (P = .000005). Patients who had 0 to 1, 2, 3, or 4 to 5 adverse factors were found to have estimated predictive incidences of acute pulmonary failure of 3%, 13%, 23%, and 34%, respectively. CONCLUSIONS: Preventive approaches at the start of induction therapy in patients at high risk of pulmonary failure may improve the outcome of these patients. Cancer 2010. © 2010 American Cancer Society. [source] Disease biology rather than age is the most important determinant of survival of patients , 60 years with acute myeloid leukemia treated with uniform intensive therapyCANCER, Issue 10 2005Vikas Gupta M.D. Abstract BACKGROUND The objectives of the current study were to evaluate the outcome of patients , 60 years with acute myeloid leukemia (AML) treated uniformly with high-dose daunorubicin containing induction and modified high-dose cytosine arabinoside containing postremission therapy, and to identify factors predictive of complete disease remission (CR) and survival. METHODS Between 1998 and 2002, the authors treated 117 newly diagnosed patients (acute promyelocytic leukemia excluded) with AML , 60 years (median, 67 years; range, 60,82 years). Karyotype (Medical Research Council classification) at diagnosis was categorized as good risk (n = 3), intermediate risk (n = 69), adverse risk (n = 26), and suboptimal/not done (n = 19). A normal karyotype was seen in 41 patients and 40 (34%) had secondary AML. RESULTS The outcome of induction included the following: CR, 62 (53%); early death, 5 (4%); death during hypoplasia, 14 (12%); and resistant disease, 36 (31%). The 3-year event-free (EFS) and overall survival (OS) rates were 9% (95% confidence interval [95% CI], 3,16%) and 17% (95% CI, 9,29%), respectively. In a univariate analysis, cytogenetics, lactate dehydrogenase level, leukocyte count, and performance status were the significant factors for EFS and OS. Age was not a significant prognostic factor for either CR or survival. In a multivariate model, adverse-risk cytogenetics, previous history of myelodysplastic syndrome or antecedent hematologic disorder, and high leukocyte count (> 30 × 109/L) were independent adverse prognostic factors for survival. The impact of adverse karyotype on EFS and OS was time dependent and was observed after 50 and 150 days, respectively. CONCLUSIONS The authors concluded that candidacy for intensive therapy in older patients should be based on biologic features of disease and fitness, rather than on age. Cancer 2005. © 2005 American Cancer Society. [source] Novel therapeutic approach to eradicate tyrosine kinase inhibitor resistant chronic myeloid leukemia stem cellsCANCER SCIENCE, Issue 7 2010Kazuhito Naka Although discovery of the tyrosine kinase inhibitor (TKI) imatinib mesylate has significantly improved the prognosis of chronic myeloid leukemia (CML) patients, a rare population of CML stem cells is known to be resistant to TKI therapy, causing recurrence of CML. However, recent progress in CML stem cell biology may present a novel therapeutic avenue for CML patients. In this review, we focus on mechanisms used by CML stem cells to maintain TKI-resistance. Comprehensive approaches including mouse genetics, prospective identification of CML stem cells, and syngenic transplantation techniques have identified several key molecules or signaling pathways, including hedgehog (Hh)/Smo, promyelocytic leukemia (PML), 5-lipoxygenase (5-LO), and forkhead box class O (FOXO), that function in CML stem cell maintenance. Inhibiting some of these factors in combination with TKI administration successfully antagonized resistance of CML stem cells to TKI therapy, resulting in efficient eradication of leukemia cells in vivo. Thus, development of methods that sensitize CML stem cells to TKI therapy may lead to novel therapies to treat CML patients. (Cancer Sci 2010) [source] Wogonin induces the granulocytic differentiation of human NB4 promyelocytic leukemia cells and up-regulates phospholipid scramblase 1 gene expressionCANCER SCIENCE, Issue 4 2008Kun Zhang Previous studies have firmly demonstrated that wogonin, a naturally occurring monoflavonoid extracted from the root of the Chinese herb medicine Scutellaria baicalensis, could effectively inhibit the proliferation of several cancer cell lines. However, little is known about the effect of wogonin on differentiation induction of leukemic cells. Here we investigate the potential role of wogonin in the proliferation and differentiation of NB4, a human promyelocytic leukemia cell line derived from a patient with acute promyelocytic leukemia. Our results indicated that wogonin significantly suppressed the proliferation and efficiently induced the differentiation of NB4 cells. NB4 cell growth was inhibited by 55,60% after treatment with 50 µM wogonin for a period of 5 days. The results of the nitroblue tetrazolium (NBT) reduction test (with 67.13% positive cells by 50 µM wogonin for 5 days), Giemsa staining (with 67.24% positive cells by 50 µM wogonin for 5 days), and the expression of mature-related cell-surface differentiation antigens CD11b and CD14 (with 70.94% CD11b+ and 5.82% CD14+ cells by 50 µM wogonin for 5 days) demonstrated an increase in the differentiation-inducing action of wogonin on the NB4 cells, which was accompanied by an increase in mRNA and protein expression of phospholipids scramblase 1 (PLSCR1). Meanwhile, the level of phosphorylated PKC, (Ser643) was dramatically increased in wogonin treated NB4 cells. Interestingly, wogonin treatment displayed little effect on the apoptosis of NB4 cells. Taken together, the results reported here demonstrated that wogonin could promote the granulocytic differentiation of NB4 cells by up-regulating the expression of PLSCR1 gene. (Cancer Sci 2008; 99: 689,695) [source] Nucleophosmin: A versatile molecule associated with hematological malignanciesCANCER SCIENCE, Issue 10 2006Tomoki Naoe Nucleophosmin (NPM) is a nucleolar phosphoprotein that plays multiple roles in ribosome assembly and transport, cytoplasmic,nuclear trafficking, centrosome duplication and regulation of p53. In hematological malignancies, the NPM1 gene is frequently involved in chromosomal translocation, mutation and deletion. The NPM1 gene on 5q35 is translocated with the anaplastic lymphoma kinase (ALK) gene in anaplastic large cell lymphoma with t(2;5). The MLF1 and RARA genes are fused with NPM1 in myelodysplastic syndrome and acute myeloid leukemia (AML) with t(3;5) and acute promyelocytic leukemia with t(5;17), respectively. In each fused protein, the N-terminal NPM portion is associated with oligomerization of a partner protein leading to altered signal transduction or transcription. Recently, mutations of exon 12 have been found in a significant proportion of de novo AML, especially in those with a normal karyotype. Mutant NPM is localized aberrantly in the cytoplasm, but the molecular mechanisms for leukemia remain to be studied. Studies of knock-out mice have revealed new aspects regarding NPM1 as a tumor-suppressor gene. This review focuses on the clinical significance of the NPM1 gene in hematological malignancies and newly discovered roles of NPM associated with oncogenesis. (Cancer Sci 2006; 97: 963,969) [source] Hydroxycinnamic Acids as DNA-Cleaving Agents in the Presence of CuII Ions: Mechanism, Structure,Activity Relationship, and Biological ImplicationsCHEMISTRY - A EUROPEAN JOURNAL, Issue 46 2009Gui-Juan Fan Abstract The effectiveness of hydroxycinnamic acids (HCAs), that is, caffeic acid (CaA), chlorogenic acid (ChA), sinapic acid (SA), ferulic acid (FA), 3-hydroxycinnamic acid (3-HCA), and 4-hydroxycinnamic acid (4-HCA), as pBR322 plasmid DNA-cleaving agents in the presence of CuII ions was investigated. Compounds bearing o -hydroxy or 3,5-dimethoxy groups on phenolic rings (CaA, SA, and ChA) were remarkably more effective at causing DNA damage than the compounds bearing no such groups; furthermore, CaA was the most active among the HCAs examined. The involvement of reactive oxygen species (ROS) and CuI ions in the DNA damage was affirmed by the inhibition of the DNA breakage by using specific scavengers of ROS and a CuI chelator. The interaction between CaA and CuII ions and the influence of ethylenediaminetetraacetic acid (EDTA), the solvent, and pH value on the interaction were also studied to help elucidate the detailed prooxidant mechanism by using UV/Vis spectroscopic analysis. On the basis of these observations, it is proposed that it is the CaA phenolate anion, instead of the parent molecule, that chelates with the CuII ion as a bidentate ligand, hence facilitating the intramolecular electron transfer to form the corresponding CaA semiquinone radical intermediate. The latter undergoes a second electron transfer with oxygen to form the corresponding o -quinone and a superoxide, which play a pivotal role in the DNA damage. The intermediacy of the semiquinone radical was supported by isolation of its dimer from the CuII -mediated oxidation products. Intriguingly, CaA was also the most cytotoxic compound among the HCAs toward human promyelocytic leukemia (HL-60) cell proliferation. Addition of exogenous CuII ions resulted in an effect dichotomy on cell viability depending on the concentration of CaA; that is, low concentrations of CaA enhanced the cell viability and, conversely, high concentrations of CaA almost completely inhibited the cell proliferation. On the other hand, when superoxide dismutase was added before, the two stimulation effects of exogenous CuII ions were significantly ameliorated, thus clearly indicating that the oxidative-stress level regulates cell proliferation and death. These findings provide direct evidence for the antioxidant/prooxidant mechanism of cancer chemoprevention. [source] Three New Triterpenoids from Potentilla multicaulisCHEMISTRY & BIODIVERSITY, Issue 1 2007Ping-Lin Li Abstract Three new triterpenoids, 19-hydroxy-2,3-secours-12-ene-2,3,28-trioic acid 3- methyl ester (1), 19-hydroxy-1-oxo-2-nor-2,3-secours-12-ene-3,28-dioic acid (2), and (3,,18,,19,)-3,28-dihydroxy-20,28-epoxyursan-24-oic acid (3), were isolated from the roots of Potentilla multicaulis. Their structures were elucidated on the basis of spectroscopic methods (IR, HR-ESI-MS, and 1D- and 2D-NMR). Compound 2b exhibited moderate cytotoxic activity against human promyelocytic leukemia (HL-60) cells. [source] | |||||||||||||||||||||||||||||||