cholecalciferol and Leukemia

Vitamin D3 deficiency is rampant which may contribute to increased risk of many diseases including cancer, cardiovascular disease and autoimmune disorders. Genomic activity of the active metabolite 1,25-dihydroxyvitamin D (1,25D) mediates most vitamin D3's actions and many gene targets of 1,25D have been characterized. As the importance of non-coding RNAs has emerged, the ability of vitamin D3via 1,25D to regulate microRNAs (miRNAs) has been demonstrated in several cancer cell lines, patient tissue and sera. In vitamin D3 intervention patient trials, significant differences in miRNAs are observed between treatment groups and/or between baseline and followup. In patient sera from population studies, specific miRNA differences associate with serum levels of 25D. The findings thus far indicate that dietary vitamin D3 in patients and 1,25D in vitro not only regulate specific miRNA(s), but may also globally upregulate miRNA levels. This article is part of a Special Issue entitled 'Vitamin D Workshop'.

Topics: Breast Neoplasms; Calcitriol; Cholecalciferol; Colonic Neoplasms; Female; Humans; Leukemia; Male; Melanoma; MicroRNAs; Neoplasms; Prostatic Neoplasms

The biologically active form of vitamin D, 1,25-dihydroxyvitamin D3 [1,25(OH)(2)D3,] possess in vitro multiple anti-cancer activities including growth arrest, induction of apoptosis and differentiation of a variety of different types of malignant cells. However, its use as a therapeutic agent is hindered by its calcemic effects. Analogs of 1,25(OH)(2)D3 have enhanced anti-tumor activity, with reduced calcemic effects. However, limited clinical studies using vitamin D compounds have not yet achieved major clinical success. Nevertheless, pre-clinical studies suggest that the combination of either 1,25(OH)(2)D3 or its analogs with other agents can have additive or synergistic anti-cancer activities, suggesting future clinical studies.

Topics: Animals; Calcitriol; Cholecalciferol; Clinical Trials as Topic; Hematopoiesis; Humans; Leukemia

The core of the 26S proteasome, the 20S prosome, is a highly organized multi-protein complex found in large amount in malignant cells. Differentiation of several cell lines, including the monoblastic U937 and the lymphoblastoid CCRF-CEM, is accompanied by a general decrease in the prosome concentration when phorbol-myrirtic-acetate (PMA) and retinoic acid plus dihydroxyvitamine D3 (RA+VD) are used. Incubation of U937 cells for three days with PMA or RA+VD causes differentiation, but the resulting patterns of prosome labeling in the cell and on the plasma membrane are not the same. In contrast, the same kind of prosome changes occur in U937 and CCRF-CEM cells when PMA is used as inducer. The intracellular distribution of prosomes is also linked to malignancy and differentiation. Prosomes are found in the nucleus and the cytoplasm of cancer cells; and treatment with RA+VD decreases the prosomes in the nucleus whereas PMA causes various prosome proteins changes. These results indicate that prosomes are important in cell regulation and in the expression of malignancy.

Topics: Cell Differentiation; Cholecalciferol; Cysteine Endopeptidases; Humans; Leukemia; Multienzyme Complexes; Proteasome Endopeptidase Complex; Tetradecanoylphorbol Acetate; Tretinoin; Tumor Cells, Cultured

The myelodysplastic syndromes represent a preleukaemic state in which a clonal abnormality of haemopoietic stem cell is characterised by a variety of phenotypic manifestations with varying degrees of ineffective haemopoiesis. This state probably develops as a sequence of events in which the earliest stages may be difficult to detect by conventional pathological techniques. The process is characterised by genetic changes leading to abnormal control of cell proliferation and differentiation. Expansion of an abnormal clone may be related to independence from normal growth factors, insensitivity to normal inhibitory factors, suppression of normal clonal growth, or changes in the immunological or nutritional condition of the host. The haematological picture is of peripheral blood cytopenias: a cellular bone marrow, and functional abnormalities of erythroid, myeloid, and megakaryocytic cells. In most cases marrow cells have an abnormal DNA content, often with disturbances of the cell cycle: an abnormal karyotype is common in premalignant clones. Growth abnormalities of erythroid or granulocyte-macrophage progenitors are common in marrow cultures, and lineage specific surface membrane markers indicate aberrations of differentiation. Progression of the disorder may occur through clonal expansion or through clonal evolution with a greater degree of malignancy. Current attempts to influence abnormal growth and differentiation have had only limited success. Clinical recognition of the syndrome depends on an acute awareness of the signs combined with the identification of clonal and functional abnormalities.

Topics: Anemia, Refractory, with Excess of Blasts; Animals; Antineoplastic Agents; Blood Cell Count; Bone Marrow; Cell Transformation, Neoplastic; Cholecalciferol; Chromosome Aberrations; Chromosome Disorders; Colony-Forming Units Assay; Colony-Stimulating Factors; DNA; Hematopoietic Stem Cells; Humans; Leukemia; Leukemia, Radiation-Induced; Mice; Myelodysplastic Syndromes; Oncogenes; Preleukemia; Rats; Tretinoin

Non-coding micro-RNA (miRNAs) regulate the protein expression responsible for cell growth and proliferation. miRNAs also play a role in a cancer cells' response to drug treatment. Knowing that leukemia and lymphoma cells show different responses to active forms of vitamin D

Topics: Cell Line; Cell Proliferation; Cholecalciferol; Humans; Leukemia; Lymphoma; MicroRNAs; Vitamin D3 24-Hydroxylase

The objective of the present study was to investigate how oxidative status influences the effectiveness of cytotoxicity of artemisinin towards cancer cells. It is hypothesized that antioxidants would reduce, whereas pro-oxidants would enhance, cytotoxicity.. Molt-4 human leukemia cells were incubated with vitamins C, E, D3, dexamethasone, or hydrogen peroxide alone or in combination with dihydroartemisinin (DHA). Concentrations of these compounds studied were similar to those achievable by oral administration. Viable cell counts were performed before (0 h) and at, 24 and 48 h after treatment.. Vitamin C, vitamin D3, dexamethasone, and H2O2 caused significant Molt-4 cell death. Vitamin E caused an increase in Molt-4 cell growth. Vitamin C and vitamin D3 significantly interacted with DHA at the 48-h time point and with H2O2 at both 24-h and 48-h time points.. Cellular oxidative status could alter the potency of artemisinin in killing cancer cells.

Topics: Antioxidants; Apoptosis; Artemisinins; Ascorbic Acid; Cell Line, Tumor; Cholecalciferol; Chromans; Dexamethasone; Humans; Hydrogen Peroxide; Leukemia; Oxidation-Reduction; Reactive Oxygen Species

Treatment of leukemia cells with 1,25-dihydroxyvitamin D3 may overcome their differentiation block and lead to the transition from myeloblasts to monocytes. To identify microRNA-mRNA networks relevant for myeloid differentiation, we profiled the expression of mRNAs and microRNAs associated to the low- and high-density ribosomal fractions in leukemic cells and in their differentiated monocytic counterpart. Intersection between mRNAs shifted across the fractions after treatment with putative target genes of modulated microRNAs showed a series of molecular networks relevant for the monocyte cell fate determination, as for example the post-transcriptional regulation of the Polo-like kinase 1 (PLK1) by miR-22-3p and let-7e-5p.

Topics: Cell Cycle Proteins; Cell Differentiation; Cholecalciferol; Gene Regulatory Networks; Granulocyte Precursor Cells; HL-60 Cells; Humans; Leukemia; MicroRNAs; Monocytes; Polo-Like Kinase 1; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; RNA Processing, Post-Transcriptional; RNA, Messenger

Acute leukemias are clonal disorders of hematopoiesis wherein a leukemic stem cell (LSC) acquires mutations that confer the capacity for unlimited self-renewal, impaired hematopoietic differentiation, and enhanced proliferation to the leukemic clone. Many recent advances in understanding the biology of leukemia have come from studies defining specific genetic and epigenetic abnormalities in leukemic cells. Three recent articles, however, further our understanding of leukemia biology by elucidating specific abnormalities in metabolic pathways in leukemic hematopoiesis. These studies potentially converge on the concept that modulation of reactive oxygen species (ROS) abundance may influence the pathogenesis and treatment of acute myeloid leukemia (AML).

Topics: Animals; Cholecalciferol; Glutarates; Hematopoiesis; Hematopoietic Stem Cells; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Iron Chelating Agents; Isocitrate Dehydrogenase; JNK Mitogen-Activated Protein Kinases; Leukemia; Leukemia, Myeloid, Acute; Models, Biological; Mutation, Missense; NADP; Neoplastic Stem Cells; Reactive Oxygen Species

Cadmium exposure has multiple effects on the immune system. These can be stimulating, leading to improved clearance of infections, or inhibiting, increasing susceptibility toward infectious agents. One in vivo observation in cadmium-exposed individuals is increased monocyte numbers. Therefore, the objective of this study is to investigate the impact of cadmium on monocyte differentiation in the HL-60 model cell line. Administered alone, cadmium had no effect. However, cadmium amplified the expression of monocyte surface markers CD11b and CD14 when differentiation was induced by 1α,25-dihydroxyvitamin D3 (VD3). Furthermore, differentiation with VD3 in the presence of cadmium augmented key monocyte functions: the capacities to perform phagocytosis and generate an oxidative burst. One important signaling pathway required for monocyte differentiation involves extracellular signal-regulated kinase (ERK)1/2. Notably, cadmium induced ERK1/2 phosphorylation in HL-60 cells. Furthermore, U0126, which inhibits ERK1/2 phosphorylation by upstream MAPK/ERK kinases (MEK)1/2, reduced VD3-mediated differentiation and abrogated the effects of cadmium. In conclusion, cadmium can augment monocytic differentiation by activating ERK1/2 signaling, leading to increased generation of functional monocytes. These increased monocyte numbers could contribute to the impact of cadmium on the immune system owing to their role in the production of pro-inflammatory cytokines and activation of T-cells by antigen presentation.

Topics: Cadmium; Calcitriol; Cell Differentiation; Cholecalciferol; HL-60 Cells; Humans; Ions; Leukemia; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Monocytes; Phosphorylation; Vitamin D

1,25-dihydroxyvitamin D3 (vitamin D3) induces differentiation of HL-60 human myeloid leukemia cells; however, the signaling mechanism governing these effects is not fully clear. Here, we show that vitamin D3 induced functional differentiation by Akt through Raf/MEK/ERK MAPK signaling. Vitamin D3 downregulated Akt, weakened Akt-Raf1 interaction, and subsequently activated the Raf/MEK/ERK MAPK pathway. Pharmacological inhibition of MEK/ERK crippled differentiation in response to vitamin D3. Ectopic overexpression of Akt inhibited MAPK signaling, downregulated cyclin-dependent kinase (CDK) inhibitors p21(Wip1/Cip1) and p27(Kip1) and blunted differentiation in response to vitamin D3 while knockdown of Akt by RNA interference gave reverse effects. Furthermore, knockdown of the CDK inhibitors by siRNA crippled the recruitment of retinoblastoma protein (Rb) from the Raf1-Rb complex and Rb hypophosphorylation, and abolished differentiation in response to vitamin D3. Vitamin D3-induced MAPK signaling mediated upregulation of the CDK inhibitors and Rb, disassociation of Raf1 and Rb, and dephosphorylation of Rb, resulting in Rb binding to transcription factor E2F1 and subsequent differentiation. Finally, knockdown of Rb by siRNA prevented vitamin D3-induced differentiation. Mutating Rb at Ser795 evokes its association with E2F1, indicating the critical role of Rb Ser795 in regulating cell differentiation. Taken together, our data suggest that vitamin D3-triggered differentiation of human myeloid leukemia cells depends on downregulation of Akt, which dissociates from Raf1 and activates MAPK signaling leading to CDK inhibitor upregulation, Raf1 disassociation from Rb, and Rb upregulation and hypophosphorylation coupled to E2F1 binding.

Topics: Cell Cycle; Cell Differentiation; Cholecalciferol; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Down-Regulation; E2F1 Transcription Factor; Extracellular Signal-Regulated MAP Kinases; HL-60 Cells; Humans; Leukemia; MAP Kinase Signaling System; Mitogen-Activated Protein Kinase Kinases; Models, Biological; Phosphorylation; Protein Binding; Proto-Oncogene Proteins c-akt; raf Kinases; Retinoblastoma Protein; Up-Regulation

The aim of this work was to study bone turnover markers, calcium homeostasis and bone mineral density (BMD) in children with acute leukemia at diagnosis, after induction chemotherapy, and during maintenance therapy to delineate abnormalities present. After evaluation of L2-L4 BMD using dual-energy X-ray absorptiometry in patients with acute myeloid and lymphoid leukemia at presentation and after treatment, the results were compared to 352 healthy age- and sex-matched Egyptian controls. Calcium homeostasis parameters and bone turnover biochemical markers (serum osteocalcin and urinary deoxypyridinoline) were also assayed and the results were compared to 12 healthy age- and sex-matched controls. Osteopenia was observed at diagnosis and during treatment in patients with acute leukemia. At diagnosis osteopenia was observed in 27 patients (62.8%): 10 (23.3%) had non severe osteopenia and 17 (39.5%) had severe osteopenia. This low BMD persisted in those who were followed up. Parathyroid hormone (PTH) (pg/ml) levels demonstrated non significant differences between children with acute leukemia at different stages of therapy and controls, while, 25 (OH) D3 (ng/ml) was significantly lower in acute leukemia patients at different stages of therapy compared to controls (p<0.001). Osteocalcin (ng/ml) is significantly lower in patients at different stages of the disease compared to controls (p<0.001) but there was no significant difference between patients at different stages of therapy. Deoxy-pyridoline cross links showed non-significant difference between the different types of acute leukemia and with controls. Osteopenia is a significant problem in children with acute leukemia at presentation and after chemotherapy. Osteopenia in acute leukemia appears to be of the low turnover type (decreased osteoblastic activity and decreased bone mineralization).

Topics: Acute Disease; Adolescent; Bone Density; Bone Diseases, Metabolic; Bone Remodeling; Child; Child, Preschool; Cholecalciferol; Egypt; Humans; Infant; Leukemia; Male; Osteoblasts; Osteocalcin; Parathyroid Hormone

Vitamin K2 (VK2) effectively induces apoptosis in leukemia cell lines, including HL-60 and U937. However, combined treatment of cells with VK2 plus 1alpha,25-dihydroxy vitamin D3 (VD3) resulted in suppression of VK2-inducing apoptosis and pronounced induction of monocytic differentiation as compared with that by VD3 alone. After achieving monocytic differentiation by pre-exposure to VK2 and VD3, the cells became resistant to various apoptotic stimuli including VK2- and H2O2-treatment and serum deprivation. Accumulation of cytoplasm p21CIP1 along with disappearance of nuclear p21CIP1 was detected in cells in response to 96-h treatment with VK2 plus VD3. A stable transfectant, U937-deltaNLS-p21CIP1, which lacked the nuclear localization signal of p21CIP1 and showed overexpression of cytoplasm p21CIP1 without monocytic differentiation, was resistant to apoptosis. These data suggest that a change of intracellular distribution of p21CIP1 from nucleus to cytoplasm along with differentiation appears to be anti-apoptotic. Clinical benefits of using VK2 for treatment of patients with leukemia and myelodysplastic syndrome (MDS) have been reported. Our data suggest that VK2 plus VD3 may be an effective combination for differentiation-based therapy for leukemia and also MDS whose cytopenias are mediated though apoptosis.

Topics: Apoptosis; Calcitriol; Cell Cycle; Cell Differentiation; Cell Line, Tumor; Cell Nucleus; Cell Proliferation; Cholecalciferol; Cyclin-Dependent Kinase Inhibitor p21; Cytoplasm; Flow Cytometry; Gene Expression Regulation, Neoplastic; HL-60 Cells; Humans; Hydrogen Peroxide; Immunoblotting; Immunoprecipitation; Leukemia; MAP Kinase Kinase 4; Models, Biological; Monocytes; Myelodysplastic Syndromes; Time Factors; Transfection; U937 Cells; Vitamin K 2

FK228 [(E)-(1S,4S,10S,21R)-7-[(Z)-ethylidene]-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23-tetraazabicyclo-[8,7,6]-tricos-16-ene-3,6,9,19,22-pentanone; FR901228, depsipeptide] is a novel histone deacetylase inhibitor that shows therapeutic efficacy in Phase I trials of patients with malignant lymphoma. However, its mechanism of action has not been characterized. In this study, we examined the in vitro and in vivo effects of FK228 on human lymphoma U-937 cells. FK228 very strongly inhibited the growth of U-937 cells with an IC(50) value of 5.92 nM. In a scid mouse lymphoma model, mice treated with FK228 once or twice a week survived longer than control mice, with median survival times of 30.5 (0.56 mg/kg) and 33 days (0.32 mg/kg), respectively (vs. 20 days in control mice). Remarkably, 2 out of 12 mice treated with FK228 (0.56 mg/kg once or twice a week) survived past the observation period of 60 days. The apoptotic population of U-937 cells time-dependently increased to 37.7% after 48 hr of treatment with FK228. In addition, FK228 induced G1 and G2/M arrest and the differentiation of U-937 cells to the CD11b(+)/CD14(+) phenotype. Expression of p21(WAF1/Cip1) and gelsolin mRNA increased up to 654- and 152-fold, respectively, after 24hr of treatment with FK228. FK228 caused histone acetylation in p21(WAF1/Cip1) promoter regions, including the Sp1-binding sites. In conclusion, (i) FK228 prolonged the survival time of scid mice in a lymphoma model, and (ii) the beneficial effects of FK228 on human lymphoma may be exerted through the induction of apoptosis, cell cycle arrest, and differentiation via the modulation of gene expression by histone acetylation.

Topics: Acetylation; Animals; Anti-Bacterial Agents; Antibiotics, Antineoplastic; Apoptosis; Cell Cycle; Cell Differentiation; Cholecalciferol; Cyclin-Dependent Kinase Inhibitor p21; Cyclins; Depsipeptides; Disease Models, Animal; Gelsolin; Histone Deacetylase Inhibitors; Histones; Humans; Leukemia; Lymphoma; Mice; Mice, SCID; Neoplasm Transplantation; Peptides, Cyclic; Promoter Regions, Genetic; RNA, Messenger; Tretinoin; U937 Cells; Xenograft Model Antitumor Assays

Research to detect new factors contributing to the etiology of acute leukemia (AL) is urgently needed. Located between latitudes 65 degrees and 70 degrees north, the population in northern Finland is exposed to extreme seasonal alterations of ultraviolet-B light and temperature. There is also a seasonal variation of both the 25(OH)- and 1,25(OH)2-D3 vitamin serum concentrations. In the present work, the frequencies of different types and age-groups at diagnosis of AL were compared during the dark and light months of the year, to uncover seasonality. Between January 1972 and December 1986, 300 consecutive patients aged >/=16 years and diagnosed as having AL were enrolled. The observed mean monthly global solar radiation, temperature measurements, and influenza epidemics were compared with the monthly occurrence of AL. Both acute lymphoblastic leukemia (ALL) (p=0.006) and total AL (p=0.015) were diagnosed excessively in the dark and cold compared with light and warm period of the year. There was a tendency for de novo leukemia to increase also in the dark and cold, but for acute myeloid leukemia (AML) patients the excess was not significant. Age >/=65 was strongly associated with the dark and cold season (p=0.003). Significantly more ALL (p=0.005) and de novo leukemias (p=0.029) were observed during influenza epidemics than during nonepidemic periods. However, a seasonality, i. e., the fluctuation of numbers of AL cases, was not determined, either monthly or during different photo- and temperature periods or influenza epidemics; this might be due to the small numbers of patients studied. Nevertheless, it is hypothesized that sunlight deprivation in the arctic winter can lead to a deficiency of the 1, 25(OH)2D3 vitamin, which might stimulate leukemic cell proliferation and block cell differentiation through dysregulation of growth factors in the bone marrow stromal cells, causing one mutation and an overt ALL in progenitor cells damaged during the current or the previous winter by influenza virus, the other mutation.

Topics: Acute Disease; Adolescent; Adult; Aged; Cholecalciferol; Cold Temperature; Disease Outbreaks; Female; Finland; Humans; Influenza, Human; Leukemia; Male; Middle Aged; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Risk Factors; Seasons; Ultraviolet Rays

The Wilms tumor gene, WT1, encodes a zinc-finger DNA binding protein which is thought to function as a tissue specific transcription factor, regulating cell growth and differentiation. High expression of WT1 has been detected in a range of acute leukemias. To elucidate a role for WT1 in leukemogenesis, we transfected the monoblastic cell line U937, which lacks detectable levels of endogenous WT1, with two isoforms of WT1. We showed that, in contrast to U937 control cells, cells constitutively expressing either of the isoforms, WT1(-KTS) or WT1(+KTS), did not respond to differentiation induction by retinoic acid or vitamin D3, as judged by the capacity to reduce nitro blue tetrazolium and morphology. Although U937 cells expressing WT1 were hampered in their ability to differentiate on incubation with retinoic acid and vitamin D3, the induced G1/G0-accumulation was similar to differentiating control cells treated with inducers. Furthermore, distinct effects on the maturation process were indicated by downregulation of the myeloid cell surface makers CD13 and CD15, while the upregulation of CD14 and CD11c on WT1 transfected cells was similar to control cells upon incubation with retinoic acid and vitamin D3. Taken together our results demonstrate that a constitutive expression of WT1 in the leukemic cell line U937 leads to impairment of differentiation responses, indicating that a high expression of WT1 can contribute to the differentiation block of acute leukemia.

Topics: Cell Cycle; Cell Differentiation; Cell Division; Cell Line; Cell Survival; Cholecalciferol; Gene Expression Regulation, Developmental; Gene Expression Regulation, Neoplastic; Genes, Wilms Tumor; Humans; Integrin alphaXbeta2; Leukemia; Lipopolysaccharide Receptors; Monocytes; Transfection; Tretinoin

In this study, U937 leukaemic cells underwent apoptotic cell death following exposure to TNF. Pre-incubation of cells for 48 h with VitD(3) (10(-8)M) induced resistance to TNF, whereas incubation with tau-IFN or GM-CSF increased susceptibility to TNF. Resistance to exogenous TNF (exTNF) following culture with VitD(3) was associated with increased expression of endogenous TNF (enTNF). The TNF inhibitors pentoxifylline(PTF) and dichloroisocoumarin (DCI) inhibited TNF synthesis by U937 cells and abrogated the increase in resistance to TNF seen with VitD(3). The tau-IFN increased TNF expression, whereas GM-CSF had little effect. The data show that the sensitivity of leukaemic cells to exTNF can be modulated by cytokines. The protective effect of VitD(3) is mediated in part by directly upregulating enTNF synthesis.

Topics: Alkaloids; Apoptosis; Cell Cycle; Cell Survival; Cholecalciferol; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Leukemia; Receptors, Tumor Necrosis Factor; Staurosporine; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

Numerous vitamin D3 analogs (VDAs) can inhibit the proliferation of cells from several types of human malignancies. The physiologically active form of vitamin D3, 1,25-dihydroxyvitamin D3(1,25D3), is formed by successive hydroxylations of cholecalciferol at the 25 and 1 alpha positions. In this study we examined the effects of the absence of the 1 alpha (OH) group, introduction of a double bond in position 16, and further modifications at the 23, 26, and 27 positions in the side chain on the potency of the VDAs. The parameters studied were the rapidity of the induction of monocytic differentiation, the cell cycle traverse, and the effects of VDAs on intracellular calcium homeostasis in HL60 cells. The results show that (1) 1,25D3 derivatives which lace the 1 alpha (OH) group have little differentiation-inducing activity, (2) hexafluorination (6F) of the terminal methyl groups in the side chain partially restores the activity of 1 alpha-desoxy compounds and potentiates the activity of 1 alpha hydroxylated compounds, and (3) 25-(OH)-16,23E-diene-26,27-hexafluoro-vitamin D2 (Ro25-9887) alone among the twelve compounds tested induces differentiation with only minimal changes in the basal levels of intracellular calcium and store-dependent calcium influx in HL60 cells. Addition of 1 alpha (OH) group to this compound increases its differentiation-inducing activity but also elevates basal calcium level. The results suggest that altered calcium homeostasis is not an obligatory component of HL60 leukemia cell differentiation, and that Ro25-9887 and related VDAs may be suitable for testing as components of anti-leukemic therapy.

Topics: Calcium; CD11 Antigens; Cell Cycle; Cell Differentiation; Cells, Cultured; Cholecalciferol; Enzyme Inhibitors; Ethanol; Flow Cytometry; G1 Phase; G2 Phase; Humans; Leukemia; Lipopolysaccharide Receptors; Manganese; Membrane Proteins; Molecular Structure; N-Formylmethionine Leucyl-Phenylalanine; S Phase; Thapsigargin

The src-related tyrosine kinase p56lck is overexpressed in the mouse leukemia cell line LSTRA. Although p56lck is thought to be a specific T-cell marker, we found that LSTRA cells can be induced to differentiate towards macrophages or granulocytes by the tumor promoter 12-O-tetradecanoylphorbol-13-acetate or the cyclic nucleotide analogue, dibutyryl cAMP, respectively. Treatment of LSTRA cells with 12-O-tetradecanoylphorbol-13-acetate resulted in marked alterations in morphology including increased size, adherence, and spreading on culture dishes. These cells also ceased proliferating, accumulated in G0-G1 and expressed nonspecific esterase activity. In contrast, although LSTRA cells treated with dibutyryl cAMP stopped growing and accumulated in G0-G1, these cells expressed functionally active chemotactic peptide receptors and became irregular and granular in appearance. Differentiation of LSTRA cells was also found to be associated with altered expression of p56lck. Thus, while 12-O-tetradecanoylphorbol-13-acetate treatment caused the cells to produce higher molecular weight forms of p56lck, dibutyryl cAMP treatment resulted in increased expression of total p56lck mRNA as well as the more mature type II p56lck mRNA transcript. There were no major alterations in p56lck kinase activity in vitro following differentiation. Phospholipase C gamma and p21rasGAP, two putative substrates for the tyrosine kinase activity of p56lck, were found to be constitutively phosphorylated on tyrosine in LSTRA cells. Tyrosine phosphorylation of these substrates was not altered following differentiation. These results indicate that LSTRA cells are relatively early precursors that have the capacity to develop along the myeloid differentiation pathway.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Antigens, Differentiation; Bucladesine; Carboxylesterase; Carboxylic Ester Hydrolases; Cell Cycle; Cell Differentiation; Cholecalciferol; Enzyme Induction; Granulocytes; Hematopoietic Stem Cells; Histocompatibility Antigens Class II; Humans; Leukemia; Lymphocyte Specific Protein Tyrosine Kinase p56(lck); Macrophages; N-Formylmethionine Leucyl-Phenylalanine; Phosphorylation; Phosphotyrosine; Protein-Tyrosine Kinases; Receptors, Formyl Peptide; Receptors, Immunologic; Receptors, Peptide; RNA, Messenger; T-Lymphocytes; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured; Tyrosine

Annexin VIII is a calcium- and phospholipid-binding protein with anticoagulant activity. Annexin VIII mRNA was found to be specifically expressed in acute promyelocytic leukemia (APL) cells; it was not found in other types of acute myeloid leukemia (AML) nor in lymphoid malignancies. Using Northern blot analysis we investigated annexin VIII expression in 142 continuous human leukemia and lymphoma cell lines at the mRNA level. While the only APL cell line, NB-4, was indeed positive, other cell lines also displayed annexin VIII mRNA: 4/22 myeloid cell lines, 8/23 monocytic cell lines, 2/8 megakaryoblastic cell lines, 5/26 lymphoma-derived cell lines, 2/10 myeloma cell lines and 1/44 lymphoid leukemia cell lines. The strongest expression was seen in NB-4 and in the Hodgkin's disease derived cell line HDLM-2. Treatment of NB-4 cells with all-trans retinoic acid (ATRA) or the phorbol ester TPA induced terminal differentiation and down-regulated annexin VIII mRNA expression rapidly within a few hours; vitamin D3 was ineffective in this regard; the protein kinase C activator Bryostatin 1 up-regulated the expression. A panel of initially negative cell lines could not be induced by any of these biomodulators to transcribe annexin VIII. The half-life (T1/2) of annexin VIII mRNA was about 3-4 h using actinomycin D as transcription inhibitor. Treatment with ATRA or TPA prior to exposure to actinomycin shortened the T1/2 to 2 h while Bryostatin 1 extended it to 6h. As 21/141 non-APL cell lines were positive, annexin VIII cannot be used as a marker gene for APL cells; however, it might be associated with myelomonocytic or erythro-megakaryoblastic precursor cells. Annexin VIII gene expression might play a unique role in the proliferation and/or differentiation of leukemic cells and could be associated with the particular abnormal hemostasis of some leukemias.

Topics: Annexins; Blotting, Northern; Bryostatins; Cell Differentiation; Cholecalciferol; Dactinomycin; Gene Expression Regulation, Neoplastic; Half-Life; Humans; Lactones; Leukemia; Leukemia, Myeloid; Leukemia, Promyelocytic, Acute; Lymphoma; Macrolides; RNA, Messenger; Tetradecanoylphorbol Acetate; Tretinoin; Tumor Cells, Cultured

We have investigated the effects of 1,25-dihydroxyvitamin D3 (D3) and/or transforming growth factor (TGF)-beta on one monocytic (U-937) and two human promyelocytic (HL-60 and AML-193) leukemic cell lines. D3 addition induces a partial monocytic maturation of the cell lines, whereas TGF-beta treatment is largely ineffective. Combined treatment with TGF-beta and D3 causes terminal monocytic maturation, as evaluated both by assessment of a large spectrum of membrane Ag and by functional assays. Furthermore, sequential addition of the two inducers showed that pretreatment with TGF-beta 1 followed by incubation with D3, but not vice versa, induces monocytic maturation as effectively as simultaneous treatment with both agents. In liquid culture the proliferative activity of these cell lines is slightly decreased by D3 and virtually unaffected by TGF-beta, whereas combined treatment with D3 and TGF-beta induces a markedly potentiated inhibitory effect. Furthermore, TGF-beta/D3 treatment (but not D3 alone) elicits the expression of membrane CD14, FcRI, FcRII, CD11a, CD11b, CD11c, ICAM-1, and PECAM-1 Ag at a level comparable to that observed on normal human monocytes. It is noteworthy that several of these Ag play an important role in monocyte physiology (e.g., CD14 Ag mediates the binding of bacterial LPS to monocytes). Treatment with both TGF-beta and D3 (but not D3 alone) induces superoxide anions and H2O2 production similar to that of circulating monocytes. In semisolid culture, D3 and TGF-beta alone cause, respectively, a marked and slight loss of cloning efficiency of the cell lines, whereas their combined addition synergistically results in a complete loss of the cloning capacity. These findings suggest a physiologic role for TGF-beta in monocyte maturation. Furthermore, they may pave the way to the design of clinical protocols combining D3 and TGF-beta in the differentiation therapy of acute promyelocytic/myelomonocytic leukemia.

Topics: Adjuvants, Immunologic; Antigens, Surface; Cell Adhesion Molecules; Cell Differentiation; Cell Division; Cell Line; Cholecalciferol; Cytokines; Drug Synergism; Humans; Hydrogen Peroxide; Leukemia; Monocytes; Nitroblue Tetrazolium; Receptors, Fc; Superoxides; Transforming Growth Factor beta; Tumor Cells, Cultured

Topics: Aspergillosis; Cholecalciferol; Humans; Leukemia; Lung Diseases, Fungal

Active vitamin D3 induced phenotypic differentiation of the human promyelocytic leukemia cell line, HL-60, cultured in serum-free medium. Upon exposure to 10(-10)-10(-7) M 1,25-(OH)2D3, 1,24S-(OH)2D3 or 1,24R(OH)2D3, monocyte-granulocyte-associated plasma membrane antigens of HL-60 cells detected by monoclonal antibodies, OKMI, 63D3 and Mo2, quantitated by fluorescence-activated cell sorter analysis, were increased time- and dose-dependently. After expose to 1,25-(OH)2D3, promotion of this antigenic expression was detected within 16 h, and the induction of differentiation continued until 96 h. The number of cells bearing transferrin receptors recognized by the monoclonal antibody, OKT9, and its density on the surface of HL-60 cells were decreased symmetrically. These effects appeared in parallel with the inhibition of cell growth, poly(ADP-ribose) content and de novo DNA-RNA synthesis. These findings indicate that 1,24S-(OH)2D3 stimulates differentiating induction of HL-60 like 1,25-(OH)2D3 in vitro and that the decrease of transferrin receptor is apparently correlated with the inhibition of proliferation.

Topics: Antibodies, Monoclonal; Antigens, Neoplasm; Cell Differentiation; Cell Division; Cell Line; Cell Membrane; Cholecalciferol; Flow Cytometry; Granulocytes; Humans; Kinetics; Leukemia; Monocytes; Phagocytosis; Phenotype; Poly Adenosine Diphosphate Ribose