Induction of Differentiation in Human Promyelocytic Leukemia HL-60 Cell Line by Niacin-related Compounds

Water-soluble vitamin, niacin, and its related compounds were examined for their differentiation-inducing activity in human promyelocytic leukemia cells (HL-60). Among the compounds, which inhibited cell proliferation measured by MTT assay, isonicotinic acid, nicotinamide N-oxide, and nicotinamide induced NBT reducing activity. HL-60 cells were differentiated into granulocyte-like cells by these compounds, judging from morphological changes and loss of nonspecific esterase activity. The differentiation-inducing activity of water-soluble vitamin and its related compounds suggest that these compounds may be applicable for medical use.     

Changes in the gene expression of C-myc and CD38 in HL-60 cells during differentiation induced by nicotinic acid-related compounds

Changes in gene expression levels of c-myc and CD38 were examined during the differentiation of HL-60 cells to granulocytes due to three nicotinic acid-related compounds. CD38 expression was increased by isonicotinic acid and all-trans-retinoic acid (ATRA). Nicotinamide and nicotinamide N-oxide drastically decreased c-myc expression, but isonicotinic acid had no effect, suggesting that these compounds differentiate HL-60 to granulocytes through different pathways. These results should provide useful information as to the mechanisms of cell differentiation.     

24-homologated 1,25-dihydroxyvitamin D3 compounds: separation of calcium and cell differentiation activities

A series of 24-homologated 1,25-dihydroxyvitamin D3 compounds have been chemically synthesized and studied with regard to their activity in inducing differentiation of human promyelocyte HL-60 cells to monocytes and in calcium mobilizing activity in vitamin D deficient rats. Homologation of 1,25-dihydroxyvitamin D3 or its delta 22 analogue by one or two carbons increases by 10-fold and three-carbon homologation reduces by half the activity in causing differentiation of HL-60. On the other hand, homologation causes a substantial decrease in in vivo calcium mobilization activity. The addition of each carbon at the 24-position decreases binding to the HL-60 receptor or rat intestinal receptor by 5-10-fold so that binding affinity of the trihomo compound for the receptors is 130 times less that of 1,25-dihydroxyvitamin D3. Thus, binding affinity for the receptor cannot account for the preferential activity of the 24-homologated compounds in inducing cell differentiation.     

Stabilization of 1,25-dihydroxyvitamin D-3 receptor in the human leukemia cell line, HL-60, with diisopropylfluorophosphate

We have investigated the reason for the lack of specific 1,25-dihydroxyvitamin D-3 binding activity in extracts of ATCC HL-60 cells. Although intact ATCC HL-60 cells specifically and saturably take up 1,25-dihydroxy[3H]vitamin D-3, whole cell extracts have little or no specific binding of 1,25-dihydroxyvitamin D-3. The absence of specific binding can now be explained by the action of a serine proteinase in these cells. When diisopropylfluorophosphate (DFP), a potent inhibitor of serine proteinase, is added to the buffer used for extraction, specific binding of 1,25-dihydroxy[3H]vitamin D-3 in the extract is observed. The loss of specific binding could not be prevented by hydrolyzed DFP or other serine proteinase inhibitors, such as phenylmethylsulfonylfluoride, benzamidine and aprotinin. The proteolytic activity from ATCC cells also destroyed specific 1,25-dihydroxy[3H]vitamin D-3 binding in high-salt extracts from pig intestinal nuclei or from another HL-60 cell line (LG HL-60 cells). However, the proteinase did not affect the levels of the specific binding in these preparations if the receptor was occupied with 1,25-dihydroxy[3H]vitamin D-3 prior to exposure to the proteinase. The binding and sedimentation characteristics of the receptors from various sources were not changed by the presence of DFP. The Kd of the receptor in ATCC HL-60 cells is 1.2.10(-10) M, which is identical to that in the LG HL-60 cells. The 1,25-dihydroxy[3H]vitamin D-3 receptor complex from the ATCC cells sediments as a single 3.5 S component and elutes from DNA-Sephadex column in two peaks at 0.09 and 0.15 M KCl. The material eluting at 0.15 M KCl has the same DNA-binding activity as preparations from pig intestine or LG HL-60 cells. Immunoprecipitation studies demonstrated that monoclonal antibodies to the pig receptor, IVG8C11, quantitatively precipitate the 1,25-dihydroxy[3H]vitamin D-3-binding activity from ATCC HL-60 cells as well as that from LG HL-60 cells or pig intestinal nuclei. Therefore, the previous failure to demonstrate the 1,25-dihydroxyvitamin D-3 receptor in ATCC HL-60 cells is because of the presence of a potent serine proteinase and not because of an abnormal or absent receptor.     

Biological activity of fluorinated vitamin D analogs at C-26 and C-27 on human promyelocytic leukemia cells, HL-60

Vitamin D compounds added to the culture medium induce HL-60 cells to differentiate into macrophage/monocytes via a receptor mechanism. This system provides a biologically relevant assay for the study of biopotency of vitamin D analogs. Using this system, the biological activity of various fluorinated derivatives of vitamin D3 was compared with that of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3). As assessed by cell morphology, nitroblue tetrazolium reduction and nonspecific esterase activity, 26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3 (26,27-F6-1,25-(OH)2D3) and 26,26,26,27,27,27-hexafluoro-1,24-dihydroxyvitamin D3 (26,27-F6-1,24-(OH)2D3) were about 10 times as potent as 1,25-(OH)2D3 in suppressing HL-60 cell proliferation and inducing cell differentiation. The biological activity of 26,26,26,27,27,27-hexafluoro-1-hydroxyvitamin D3 (26,27-F6-1-OH-D3) was equal to that of 1,25-(OH)2D3 in this system. 1,25-(OH)2D3 and its fluorinated analogs exerted their effects on HL-60 cells in a dose-dependent manner. HL-60 cells have a specific receptor for 1,25-(OH)2D3 with an apparent Kd of 0.25 nM, identical with that of chick intestinal receptor. While the binding affinities of 26,27-F6-1,25-(OH)2D3 and 26,27-F6-1,24-(OH)2D3 for chick intestinal receptor were lower than that of 1,25-(OH)2D3 by factors of 3 and 1.5, respectively, they were as competent as 1,25-(OH)2D3 in binding to HL-60 cell receptor. The ability of 26,27-F6-1-OH-D3 to compete for receptor protein from HL-60 cells and chick intestine was about 1/70 that of 1,25-(OH)2D3. These results indicate that trifluorination of carbons 26 and 27 of vitamin D3 can markedly enhance the effect on HL-60 cells.     

Effects of novel 26,27-dialkyl analogs of 1 alpha,25-dihydroxyvitamin D3 on differentiation-inducing activity of human promyelocytic leukemia (HL-60) cells in serum-supplemented or serum-free culture.

Monocytic differentiation-inducing activity of steroidal side chain-lengthened 26,27-dialkyl analogs of 1 alpha,25-dihydroxyvitamin D3 was examined in human promyelocytic leukemia (HL-60) cells in serum-supplemented or serum-free culture. The order of in vitro potency for reducing nitroblue tetrazolium was 1 alpha,25-dihydroxy-26,27-dimethylvitamin D3 greater than or equal to 1 alpha,25-dihydroxy-26,27-diethylvitamin D3 much greater than 1 alpha,25-dihydroxy-26,27-dipropylvitamin D3 under serum-free culture conditions. Analysis by sucrose density-gradient centrifugation or polyethylene glycol precipitation technique showed that the potency order for differentiation-inducing activity correlated well with binding affinity of these analogs for vitamin D3 receptor of HL-60 cells. Under serum-supplemented culture conditions, the lack of correlation between biologic activity and analog-binding affinity for receptor was caused by differences in binding affinity of these analogs for serum vitamin D-binding proteins. These results suggest that serum vitamin D-binding proteins apparently modulate monocytic differentiation of HL-60 cells by these analogs under serum-supplemented culture conditions.     

Expression of CD38 in human promyelocytic leukemia HL-60 cell line during differentiation by niacin-related compounds

It was found that three niacin-related compounds, isonicotinic acid, nicotinamide, and nicotinamide N-oxide, induced granulocytic differentiation in HL-60 cells. We investigated the expression of CD38, which catalyzes the synthesis of cyclic ADP-ribose, a Ca2+ mobilizer, during differentiation by niacin-related compounds. It was found that CD38 was induced by isonicotinic acid, whereas nicotinamide and nicotinamide N-oxide containing an amino group did not induce it. The difference in expression of CD38 may provide some useful information for the elucidation of the mechanisms of cell differentiation.     

Changes in the Gene Expression of C-myc and CD38 in HL-60 Cells during Differentiation Induced by Nicotinic Acid-Related Compounds

Changes in gene expression levels of c-myc and CD38 were examined during the differentiation of HL-60 cells to granulocytes due to three nicotinic acid-related compounds. CD38 expression was increased by isonicotinic acid and all-trans-retinoic acid (ATRA). Nicotinamide and nicotinamide N-oxide drastically decreased c-myc expression, but isonicotinic acid had no effect, suggesting that these compounds differentiate HL-60 to granulocytes through different pathways. These results should provide useful information as to the mechanisms of cell differentiation.     

Expression of CD38 in Human Promyelocytic Leukemia HL-60 Cell Line during Differentiation by Niacin-related Compounds

It was found that three niacin-related compounds, isonicotinic acid, nicotinamide, and nicotinamide N-oxide, induced granulocytic differentiation in HL-60 cells. We investigated the expression of CD38, which catalyzes the synthesis of cyclic ADP-ribose, a Ca²⁺ mobilizer, during differentiation by niacin-related compounds. It was found that CD38 was induced by isonicotinic acid, whereas nicotinamide and nicotinamide N-oxide containing an amino group did not induce it. The difference in expression of CD38 may provide some useful information for the elucidation of the mechanisms of cell differentiation.     

Synthesis and biological activity of N,N-dialkylaminoalkyl-substituted bisindolyl and diphenyl pyrazolone derivatives

New compounds, structurally related to the potent protein kinase C inhibitor staurosporine, with a bisindolylpyrazolone framework and substituted on the pyrazolone nitrogens with N,N-dialkylaminoalkyl side chain, were synthesized and evaluated for growth-inhibitory properties in several human cell lines. Many showed inhibition of TNF-alpha production in response to the tumor promotor TPA on HL-60 cells. The apoptotic activity on HeLa cells has been examined for several of these compounds.     

5－氮－2＇－脱氧胞苷（5－aza－CdR）对HL－60细胞分化和DNA甲基化酶的影响

以５－氮－２＇－脱氧胞苷（５－ａｚａ－ＣｄＲ）为诱导物,在０．５μｍｏｌ／Ｌ的最佳浓度下,可诱导ＨＬ－６０细胞分化达１５％左右。同时,用［￣３Ｈ］－ｍｅｔｈｙｌ－ｓ－ａｄｅｎｏｓｙｌｍｅｔｈｉｏｎｉｎｅ（￣３Ｈ－ＳＡＭ）为底物,通过同位素参入法,测定了不同浓度诱导物对ＨＬ－６０细胞ＤＮＡ甲基化酶活力的影响,发现在最佳诱导物浓度下,可使ＨＬ－６０细胞ＤＮＡ甲基化酶活力明显下降,此外,也比较了不同分化水平的ＨＬ－６０细胞中具有不同甲基化水平的ＤＮＡ在体外接受甲基的能力,从而证明５－ａｚａ－ＣｄＲ诱导ＨＬ－６０细胞分化与其ＤＮＡ甲基化状态密切相关。     

Apoptosis induced by the flavonoid from lemon fruit (Citrus limon BURM. f.) and its metabolites in HL-60 cells

The flavonoid from lemon fruit (Citrus limon BURM. f.) and its metabolites, particularly eriodictyol, 3,4-dihydroxyhydrocinnamic acid, and phloroglucinol had the function of DNA fragmentation in HL-60 cells when analyzed by flow cytometry. An apoptotic DNA ladder and chromatin condensation were observed in HL-60 cells when treated with these compounds. The caspase inhibitor prevented DNA fragmentation. These compounds are anticipated to be useful for medical purposes.     

Biological activity of 24,24-difluoro-1 alpha, 25-dihydroxyvitamin D3 and 1 alpha, 25-dihydroxyvitamin D3-26,23-lactone in inducing differentiation of human myeloid leukemia cells

Vitamin D compounds added to the culture medium induce differentiation of human myeloid leukemia cells (HL-60 cells) by binding to a specific cytosol receptor protein. This system provides a biologically relevant and technically simple assay to examine the relationship between molecular structure and biological activity of vitamin D compounds. Using this culture system, the biological activity of 24,24-F2-1 alpha,25(OH)2D3 and 1 alpha,25(OH)2D3-26,23-lactone was assayed. 24,24-F2-1 alpha,25(OH)2D3 was four to seven times more potent than 1 alpha,25(OH)2D3 in inducing phagocytosis and C3 rosette formation of HL-60 cells, though both compounds bound equally well to the cytosol receptor, suggesting that the defuorination at the 24-carbon position may stimulate membrane permeability of the compound. 1 alpha,25(OH)2D3-26,23-lactone, on the other hand, was only 1/200th as active as 1 alpha,25(OH)2D3. The binding affinity of the lactone for the cytosol receptor was identical with that of 1 alpha (OH)D3, suggesting that the lactone formation between the 26 and 23 positions masks the function of the 25-hydroxyl group. The binding affinity of vitamin D3 derivatives to the specific cytosol receptor of HL-60 cells was well correlated with that of intestinal cytosol protein specifically bound to 1 alpha,25(OH)2D3.     

Apoptosis induced by nicotinamide-related compounds and quinolinic acid in HL-60 cells

In our previous paper, we have reported that niacin-related compounds, particularly picolinic acid, dipicolinic acid, and isonicotinamide, induced apoptosis in HL-60 cells but that niacin did not. Moreover, picolinamide, N1-methylnicotinamide, 6-aminonicotinamide, quinolinic acid, and cinchomeronic acid also had the function of DNA fragmentation in HL-60 cells analyzed by flow cytometry, the ratio of DNA fragmentation finally being about 40% after treatment with these compounds at 10 mM for 24 h. In this study, we found that these compounds also induced apoptosis in HL-60 cells. The wide-spectrum caspase inhibitors prevented DNA fragmentation induced by these compounds. Interestingly, 6-aminonicotinamide induced apoptosis at a comparatively low concentration, while picolinic acid, dipicolinic acid, and isonicotinamide did not at 1 mM. Our results suggest that both NAD metabolism and NAD biosynthesis may be related to the process of apoptosis induced by niacin-related compounds.     

Maturation of human promyelocytic leukemia cells induced by nicotinamide: Evidence of a regulatory role for ADP-ribosylation of chromosomal proteins

We have studied the role of ADP-ribosylation of chromosomal proteins in the regulation of myeloid cell maturation using the HL-60 cell line as a model. Nuclei isolated from this human promyelocytic leukemia cell line contained (ADP-ribose)_n synthetase activity, whereas little or no enzymatic activity was detectable in normal human blood neutrophils. Furthermore, the activity of (ADP-ribose)_n synthetase was decreased in HL-60 cells when they were induced to mature with retinoic acid (RA). To determine whether reduced (ADP-ribose)_n synthetase activity is simply a result of induced maturation or whether it is a necessary precedent event for the maturation process, we evaluated the effects of nicotinamide (NAm) and its methyl derivative, N′-methylnicotinamide (N′-Met-NAm), agents which decrease ADP-ribosylation. Treatment of HL-60 cells with these drugs caused the cells to undergo maturation and to acquire certain of the morphologic, functional, and biochemical characteristics of normal neutrophils. N′-Met-NAm was more potent than NAm in inducting maturation; at a concentration of 0.8 mM, it caused greater than 80% of the cells to mature, whereas a tenfold greater concentration of NAm was required to induce a similar degree of maturation. NAm and N′-Met-NAm also potentiated the maturation of HL-60 cells induced by RA. Exposure of cells to noninducing concentrations of these compounds caused a leftward shift in the dose-response curve for RA; maturation was observed at 10^?11 M RA in the presence of either 2 mM NAm or 0.2 mM N′-Met-NAm while 10^?9 M RA was required to induce maturation in their absence. A leftward shift in the dose response curve for maturation in the presence of low doses of NAm or N′-Met-NAm did not occur with another inducer, dimethyl formamide (DMF). Two enzymes, NAD glycohydrolase and tissue transglutaminase, that are abundant in macrophages, were induced by RA but not by NAm. N′-Met-NAm decreased by about 75% the amount of endogenous (ADP-ribose)_n in a selected fraction of chromosomal proteins which included histone H₁ and the nonhistone high mobility group proteins. The results of this study support the concept that ADP-ribosylation of chromosomal proteins influences the regulation of human myeloid cell maturation.     

Evidence for a causal role of CD38 expression in granulocytic differentiation of human HL-60 cells

Granulocytic differentiation of human HL-60 cells can be induced by retinoic acid and is accompanied by a massive expression of CD38, a multi-functional enzyme responsible for metabolizing cyclic ADP-ribose (cADPR), a Ca(2+) messenger. Immunofluorescence staining showed that CD38 was expressed not only on the surface of intact HL-60 cells but also intracellularly, which was revealed after permeabilization with Triton. Concomitant with CD38 expression was the accumulation of cADPR, and both time courses preceded the onset of differentiation, suggesting a causal role for CD38. Consistently, treatment of HL-60 cells with a permeant inhibitor of CD38, nicotinamide, inhibited both the CD38 activity and differentiation. More specific blockage of CD38 expression was achieved by using morpholino antisense oligonucleotides targeting its mRNA, which produced a corresponding inhibition of differentiation as well. Similar inhibitory effects were observed when CD38 expression was reduced by the RNA interference technique targeting two separate regions of the coding sequence of CD38. Further support came from transfecting HL-60 cells with a Tet-On expression vector containing a full-length CD38. Subsequent treatments with doxycycline induced both CD38 expression and differentiation in the absence of retinoic acid. These results provide the first evidence that CD38 expression and the consequential accumulation of cADPR play a causal role in mediating cellular differentiation.     

Monocytic differentiation of HL-60 cells is characterized by the nuclear translocation of phosphatidylinositol 3-kinase and of definite phosphatidylinositol-specific phospholipase C isoforms.

Immunochemical and immunocytochemical data indicate that nuclei of HL-60 cells contain different enzymes involved in the phosphoinositide cycle, such as PI 3-K and the phosphatidylinositol-specific PLC isoforms beta3, gamma1 and gamma2. These enzymes translocate differently to the nuclear fraction when HL-60 cells are treated with differentiating doses of vitamin D3: PI 3-K translocated progressively to the nucleus in parallel with full differentiation until 96 hours. PLC beta3 increased until 72 hours of treatment and then lowered its intranuclear amount and PLC gamma1 was unchanged at all the examined times. PLC gamma2 nuclear translocation increased progressively until 96 hours of vitamin D3 administration. A fourth PLC isozyme, beta2, present in the cytoplasm of untreated cells, translocates to the cytoplasm after vitamin D3 addition and reaches the highest concentration at the end of monocytic differentiation. Terminal monocytic differentiation was characterized at the nuclear level by high levels of PI 3-K and PLC gamma2 and by the novel expression of PLC beta2. We then observed that the xi isoform of PKC, constitutively present in nuclei of HL-60 cells, translocated to the nucleus when cells were induced to differentiate along the monocytic lineage, but the nuclear translocation of PKC xi was blocked as a consequence of PI 3-K inhibition by Wortmannin. These findings indicate that the main components of the noncanonical and canonical inositol lipid signal transduction pathways, including PI 3-K, PLC beta2 and beta3, PLC gamma2, undergo nuclear translocation and may therefore play a relevant role during monocytic differentiation at the nuclear level. Furthermore, PKC xi nuclear translocation appears to be related to PI 3-K activity.     

Effects of vitamin D3 and IFN-gamma on the synthesis of the second complement component, C2, by a human myeloid leukemia (HL-60) cell line

HL-60 cells, a human promyelocytic cell line, can be induced to differentiate along either monocytic or granulocytic pathways. The production of the second complement component, C2, is a marker of monocytic differentiation and can be up-regulated by cytokine stimulation. We studied the effects of IFN-gamma and vitamin D3, two factors previously shown to induce monocytic differentiation of HL-60 cells, on C2 production and C2 mRNA content. We found that HL-60 cells produce little if any C2 but can be induced to synthesize C2 by IFN-gamma. Vitamin D3 pretreatment followed by IFN-gamma stimulation resulted in earlier and greater production of C2. HL-60 cells did not contain detectable amounts of C2 mRNA unless they were stimulated with IFN-gamma. Pretreatment with vitamin D3 followed by IFN-gamma stimulation resulted in a 147% increase in C2 mRNA content compared with IFN-gamma stimulation alone. These results indicate that the up-regulation of C2 production by IFN-gamma and vitamin D3 is pretranslational although additional posttranslational effects were not excluded. C2 production by these cells is a useful marker of monocytic differentiation.     

新生牛肝中三种低分子化合物牛磺酸、鸟氨酸、肌肽对HL-60细胞凋亡的诱导作用

目的:研究三种新生牛肝源低分子化合物:牛磺酸、鸟氨酸、肌肽对HL-60白血病细胞增殖的抑制作用并探讨其调控机理.方法:用MTT法分别检测三种活性成分作用后HL-60细胞和正常人淋巴细胞的存活率.分别用琼脂糖凝胶电泳,顺磁共振ESR技术,免疫组化法测定其对HL-60细胞的核DNA、氧自由基活性和细胞周期蛋白水平的影响.结果:三种化合物能够有效地抑制HL-60细胞的增殖,而对正常的人淋巴细胞的生长没有抑制作用;三种化合物使HL-60细胞的核DNA产生30 kb片段,使HL-60细胞内的氧自由基活性降至痕量水平,并下调HL-60的p45/skp2的水平,而上调p27/kip的水平.结论:牛磺酸、鸟氨酸、肌肽能够通过调控细胞周期蛋白的水平而选择性的抑制肿瘤细胞的增殖.