The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Pavel Pisa - One of the best experts on this subject based on the ideXlab platform.
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Supression of telomerase activity in HL60 cells after treatment with differentiating agents
Leukemia, 1996Co-Authors: Danke Xu, Astrid Gruber, C. Peterson, Pavel PisaAbstract:The human promyelocytic leukemic HL60 cells are immortal and as such express high levels of telomerase activity. All-trans retinoic acid (ATRA) and 1 alpha, 25 dihydroxyvitamin D3 (VD3) induce differentiation of HL60 cells into CD11b+ mature granulocytes and monocytes, respectively. We studied telomerase activity after differentiation of HL60 cells. A marked inhibition of the enzyme activity was observed in the differentiated CD11b+ cells after 72-120 h treatment with either differentiating agent. In contrast, the VD3-treated CD11b- HL60 cells, which failed to undergo differentiation and human erythroleukemic cell line K562, exposed to ATRA retained high levels of telomerase activity. This finding suggests, that telomerase activity is repressed as a differentiation-associated event in HL60 cells. Our results provide the first evidence that immortal leukemic cells, like normal human cells, have a telomerase repressing mechanism which can be activated by differentiation and thus lead to the suppression of telomerase activity. This in vitro model may be useful for studies of the mechanisms controlling telomerase activity and in the search for physiological telomerase modulators.
Jolanta Tarasiuk - One of the best experts on this subject based on the ideXlab platform.
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Antitumour effects of selected plant polyphenols, gallic acid and ellagic acid, on sensitive and multidrug-resistant leukaemia HL60 cells.
Phytotherapy Research, 2019Co-Authors: Agnieszka Maruszewska, Jolanta TarasiukAbstract:: The aim of this study was to examine the antitumour effects of plant phenolic acids, gallic acid (GA) and ellagic acid (EA), on human promyelocytic leukaemia sensitive HL60 cell line and its resistant sublines exhibiting two MDR phenotypes: HL60/VINC (overexpressing P-glycoprotein) and HL60/MX2 (characterized by the presence of mutated α isoform of topoisomerase II). Both studied compounds exerted comparable cytotoxic activities towards sensitive HL60 cells and their MDR counterparts. It was also found that GA and EA modulated the cellular level of reactive oxygen species in a dose-dependent and time-dependent manner. Furthermore, it was demonstrated that GA (IC90 ) and EA (IC50 and IC90 ) significantly increased the percentage of sub-G1 subpopulation of all studied leukaemia cells causing oligonucleosomal DNA fragmentation. Both compounds used at IC90 triggered mainly the apoptotic death of these cells. However, GA had no effect on the activity of caspase-3 as well as caspase-8 in sensitive HL60 cells and their MDR counterparts. In contrast, EA provoked a significant activation of these caspases in all studied leukaemia cells. It was also found that lysosomes were not involved in triggering programmed death of sensitive HL60 and MDR cells by GA and EA.
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Anthraquinone antitumour agents, doxorubicin, pirarubicin and benzoperimidine BP1, trigger caspase-3/caspase-8-dependent apoptosis of leukaemia sensitive HL60 and resistant HL60/VINC and HL60/DOX cells.
Anti-cancer drugs, 2012Co-Authors: Robert Nowak, Jolanta TarasiukAbstract:We examined the effect of selected anthraquinone antitumour agents - doxorubicin (DOX), pirarubicin (PIRA) and benzoperimidine BP1 - on inducing apoptosis of the sensitive leukaemia HL60 cell line and its multidrug resistance sublines overexpressing P-glycoprotein (HL60/VINC) and multidrug resistance-associated protein 1 (HL60/DOX). All agents used at IC50 and IC90 were able to influence the cell cycle of sensitive HL60 and resistant cells and induce apoptosis. Interestingly, it was seen that HL60/VINC cells were more susceptible to undergo caspase-3/caspase-8-dependent apoptosis induced by the studied anthraquinone compounds compared with HL60 and HL60/DOX cells. However, the examined agents did not change the expression of Fas receptors on the surface of HL60-sensitive and-resistant cells.
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in vitro antileukaemic activity of extracts from berry plant leaves against sensitive and multidrug resistant HL60 cells
Cancer Letters, 2006Co-Authors: Katarzyna Skupien, Jan Oszmianski, Dorota Kostrzewanowak, Jolanta TarasiukAbstract:The aim of the present study was to determine in vitro antileukaemic activity of extracts obtained from selected berry plant leaves (Fragaria x ananassa Duch. cv Elsanta, raspberry Rubus ideus L. cv Polana and blueberry Vaccinium corymbosum L. cv Bluecrop) against promyelocytic HL60 cell line and its multidrug resistant sublines exhibiting two different MDR phenotypes: HL60/VINC (overexpressing P-glycoprotein) and HL60/DOX (overexpressing MRP1 protein). It was found that the blueberry extract was the most efficient against sensitive HL60 cell line (about 2-fold more active than strawberry and raspberry extracts) but presented much lower activity towards resistant cells. In contrast, strawberry and raspberry extracts exhibited the high cytotoxic activity against sensitive leukaemia HL60 cell line as well as its MDR sublines. The values of resistance factor (RF) found for these extracts were very low lying in the range 0.32÷2.0.
Masuko Kobori - One of the best experts on this subject based on the ideXlab platform.
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induction of apoptosis in cancer cells by bilberry vaccinium myrtillus and the anthocyanins
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Naomi Katsube, Tojiro Tsushida, Keiko Iwashita, Koji Yamaki, Masuko KoboriAbstract:Among ethanol extracts of 10 edible berries, bilberry extract was found to be the most effective at inhibiting the growth of HL60 human leukemia cells and HCT116 human colon carcinoma cells in vitro. Bilberry extract induced apoptotic cell bodies and nucleosomal DNA fragmentation in HL60 cells. The proportion of apoptotic cells induced by bilberry extract in HCT116 was much lower than that in HL60 cells, and DNA fragmentation was not induced in the former. Of the extracts tested, that from bilberry contained the largest amounts of phenolic compounds, including anthocyanins, and showed the greatest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Pure delphinidin and malvidin, like the glycosides isolated from the bilberry extract, induced apoptosis in HL60 cells. These results indicate that the bilberry extract and the anthocyanins, bearing delphinidin or malvidin as the aglycon, inhibit the growth of HL60 cells through the induction of apoptosis. Only pure delphinidin and the glycoside isolated from the bilberry extract, but not malvidin and the glycoside, inhibited the growth of HCT116 cells.
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induction of apoptosis in cancer cells by bilberry vaccinium myrtillus and the anthocyanins
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Naomi Katsube, Tojiro Tsushida, Keiko Iwashita, Koji Yamaki, Masuko KoboriAbstract:Among ethanol extracts of 10 edible berries, bilberry extract was found to be the most effective at inhibiting the growth of HL60 human leukemia cells and HCT116 human colon carcinoma cells in vitro. Bilberry extract induced apoptotic cell bodies and nucleosomal DNA fragmentation in HL60 cells. The proportion of apoptotic cells induced by bilberry extract in HCT116 was much lower than that in HL60 cells, and DNA fragmentation was not induced in the former. Of the extracts tested, that from bilberry contained the largest amounts of phenolic compounds, including anthocyanins, and showed the greatest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Pure delphinidin and malvidin, like the glycosides isolated from the bilberry extract, induced apoptosis in HL60 cells. These results indicate that the bilberry extract and the anthocyanins, bearing delphinidin or malvidin as the aglycon, inhibit the growth of HL60 cells through the induction of apoptosis. Only pure delphinidin and the glycoside i...
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Proanthocyanidins from barley bran potentiate retinoic acid-induced granulocytic and sodium butyrate-induced monocytic differentiation of HL60 cells.
Bioscience Biotechnology and Biochemistry, 1998Co-Authors: Koji Tamagawa, Sei Fukushima, Masuko Kobori, Hiroshi Shinmoto, Tojiro TsushidaAbstract:Polyphenol extract from barley bran (BPE) induced nitro blue tetrazolium (NBT) reducing activity and alpha-naphthyl butyrate esterase activity in HL60 human myeloid leukemia cells. Because BPE induced the biochemical markers of HL60 cell differentiation, we investigated the effects of proanthocyanidins isolated from BPE on the HL60 cell differentiation of HL60 cells. Prodelphinidin B-3, T1, T2, and T3 induced 26-40% NBT-positive cells and 22-32% alpha-naphthyl butyrate esterase-positive cells. Proanthocyanidins potentiated retinoic acid (all-trans-retinoic acid)-induced granulocytic and sodium butyrate-induced monocytic differentiation in HL60 cells.
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Structure-activity Relationships of Flavonoids and the Induction of Granulocytic- or Monocytic-Differentiation in HL60 Human Myeloid Leukemia Cells
Bioscience biotechnology and biochemistry, 1998Co-Authors: Tohru Takahashi, Masuko Kobori, Hiroshi Shinmoto, Tojiro TsushidaAbstract:The flavones apigenin and luteolin strongly inhibited the growth of HL60 cells and induced morphological differentiation into granulocytes. The flavonol quercetin inhibited the cell growth and induced a differentiation marker, i.e., NBT reducing ability. However quercetin-treated cells were not morphologically differentiated into granulocytes. The chalcone phloretin weakly induced NBT reducing ability and a marker of monocytic differentiation α-naphthyl butyrate esterase activity in the cells. Quercetin and phloretin appeared to induce the differentiation of HL60 cells into monocytes. The proportion of α-naphthyl butyrate esterase-positive cells induced by genistein was less than that of the NBT-positive cells. Some of the nuclei in genistein-treated HL60 cells morphologically changed. Genistein must have induced both granulocytic and monocytic differentiation of HL60 cells. The flavonols galangin and kaempferol, which had fewer hydroxyl group(s) in the B-ring than quercetin, and the flavanone naringenin inhibited the growth but did not induce the differentiation of HL60 cells.
Tatiana Carolina Albaloureiro - One of the best experts on this subject based on the ideXlab platform.
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nadph oxidase dependent production of reactive oxygen species induces endoplasmatic reticulum stress in neutrophil like HL60 cells
PLOS ONE, 2015Co-Authors: Wilson Mitsuo Tatagiba Kuwabara, Liling Zhang, Irmgard Schuiki, Rui Curi, Allen Volchuk, Tatiana Carolina AlbaloureiroAbstract:Reactive oxygen species (ROS) primarily produced via NADPH oxidase play an important role for killing microorganisms in neutrophils. In this study we examined if ROS production in Human promyelocytic leukemia cells (HL60) differentiated into neutrophil-like cells (dHL60) induces ER stress and activates the unfolded protein response (UPR). To cause ROS production cells were treated with PMA or by chronic hyperglycemia. Chronic hyperglycemia failed to induce ROS production and did not cause activation of the UPR in dHL60 cells. PMA, a pharmacologic NADPH oxidase activator, induced ER stress in dHL60 cells as monitored by IRE-1 and PERK pathway activation, and this was independent of calcium signaling. The NADPH oxidase inhibitor, DPI, abolished both ROS production and UPR activation. These results show that ROS produced by NADPH oxidase induces ER stress and suggests a close association between the redox state of the cell and the activation of the UPR in neutrophil-like HL60 cells.
Danke Xu - One of the best experts on this subject based on the ideXlab platform.
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Supression of telomerase activity in HL60 cells after treatment with differentiating agents
Leukemia, 1996Co-Authors: Danke Xu, Astrid Gruber, C. Peterson, Pavel PisaAbstract:The human promyelocytic leukemic HL60 cells are immortal and as such express high levels of telomerase activity. All-trans retinoic acid (ATRA) and 1 alpha, 25 dihydroxyvitamin D3 (VD3) induce differentiation of HL60 cells into CD11b+ mature granulocytes and monocytes, respectively. We studied telomerase activity after differentiation of HL60 cells. A marked inhibition of the enzyme activity was observed in the differentiated CD11b+ cells after 72-120 h treatment with either differentiating agent. In contrast, the VD3-treated CD11b- HL60 cells, which failed to undergo differentiation and human erythroleukemic cell line K562, exposed to ATRA retained high levels of telomerase activity. This finding suggests, that telomerase activity is repressed as a differentiation-associated event in HL60 cells. Our results provide the first evidence that immortal leukemic cells, like normal human cells, have a telomerase repressing mechanism which can be activated by differentiation and thus lead to the suppression of telomerase activity. This in vitro model may be useful for studies of the mechanisms controlling telomerase activity and in the search for physiological telomerase modulators.