[Effect of Recombinant Adenovirus AdE-SH2-Caspase 8 on the Apoptosis of Imatinib-resistant K562/G01 Cell Line].

PubMed

Wang, Lin; Fei, Chang; Huang, Zheng-Lan; Li, Hui; Liu, Zhang-Lin; Feng, Wen-Li

2015-08-01

To investigate the effect of SH2-Caspase 8 fusion protein expressed by recombinant adenovirus AdE-SH2-Caspase8-HA-GFP (SC) on the apoptosis of K562/G01 cell line, which is a BCR/ABL positive chronic myeloid leukemia cell line and resistant to imatinib. The K562/G01 cell line was infected with AdE-SH2-Caspase 8-HA-GFP adenovirus (SC), then the cells were divided into 3 groups: AdE-SH2m-Caspase 8-HA-GFP (SmC) group, AdE-GFP (CMV) group and PBS group as control. The infection efficiency was observed under fluorescent microscopy and by flow cytometry. The expression of fusion protein SH2-Caspase 8-HA was measured by Western blot. The morphology of the cells detected by Wright's staining. The apoptosis of the cells were detected by flow cytometry and DNA ladder. The expression of Caspase 3 and PARP were detected by Western blot. The infection efficiency of SC on K562/G01 cells was high which was confirmed by fluorescent microscopy and FCM. SH2-Caspase 8-HA fusion protein were expressed correctly in K562/G01 cells. After treatment with SC the apoptosis of K562/G01 cells could be observed by microscopy. The result of FCM showed that early apoptosis of K562/G01 cells increased significantly as compared with control groups (P < 0.05). DNA ladder showed that the classic DNA ladders appeared in K562/G01 cells after treatment with SC. The wester blot detection showed that the expression level of apoptosis-related protein Caspase 3 and PARP increased. The recombinant adenovirus SC expressing SH2-Caspase 8 fusion protein can induces the apoptosis of K562/G01 cells.

Low‑dose radiation‑induced apoptosis in human leukemia K562 cells through mitochondrial pathways.

PubMed

Xin, Yong; Zhang, Hai-Bin; Tang, Tian-You; Liu, Gui-Hong; Wang, Jian-She; Jiang, Guan; Zhang, Long-Zhen

2014-09-01

High‑dose total body irradiation (TBI) has an established role as preparative regimen for bone‑marrow transplantation in the treatment of chronic myelogenous leukemia (CML), but this regimen still has a relatively high rate of acute and late toxicity. Low‑dose radiation (LDR) induces apoptosis of tumor cells and has numerous beneficial effects on normal tissues, including radiation homeostasis and adaptive response. Based on the previous evidence, in the present study, K562 cells were exposed to LDR, high‑dose radiation (HDR), and LDR in combination with HDR to investigate the possible mechanism of the apoptotic effect and hypersensitivity induced by LDR. The apoptotic rate increased in all radiation groups in a time‑dependent manner. An upregulation of Bax protein expression and a downregulation of Bcl‑xl in a dose‑dependent manner in human leukemia K562 cells was observed. However, the expression of p53 protein did not change in all of the radiation cell groups. The mitochondrial membrane potential (ΔΨm) in K562 cells decreased in all of the radiation cell groups in a dose‑dependent manner. Furthermore, the decrease of ΔΨm was enhanced in the LDR/HDR group compared with that in the LDR or HDR groups. The activity of caspase‑3 was enhanced in all of the radiation groups. In the LDR/HDR group, the activity of caspase‑3 was higher than that in the HDR or LDR groups. The present study provided preliminary experimental evidence of LDR being beneficial in combination with TBI in the treatment of CML.

Induction of apoptosis in K562 cells by dicyclohexylammonium salt of hyperforin through a mitochondrial-related pathway.

PubMed

Liu, Jin-Yun; Liu, Zhong; Wang, Dong-Mei; Li, Man-Mei; Wang, Shao-Xiang; Wang, Rui; Chen, Jian-Ping; Wang, Yi-Fei; Yang, De-Po

2011-04-25

Hyperforin is an abundant phloroglucinol-type constituent isolated from the extract of the flowering upper portion of the plant Hypericum perforatum L. The dicyclohexylammonium salt of hyperforin (DCHA-HF) has exhibited antitumor and antiangiogenic activities in various cancer cells. Here, the antitumor effects of DCHA-HF on the chronic myeloid leukemia K562 cell line were investigated for the first time. DCHA-HF exhibited dose- and time-dependent inhibitory activities against K562 cells, with IC(50) values of 8.6 and 3.2 μM for 48 h and 72 h of treatment, respectively, which was more effective than that of the hyperforin. In contrast, little cytotoxic activity was observed with DCHA-HF on HUVECs. DCHA-HF treatment resulted in induction of apoptosis as evidenced from DNA fragmentation, nuclear condensation and increase of early apoptotic cells by DAPI staining analysis, TUNEL assay and Annexin V-FITC/PI double-labeled staining analysis, respectively. Moreover, DCHA-HF elicited dissipation of mitochondrial transmembrane potential that commenced with the release of cytochrome c through down-regulation of expression of anti-apoptotic proteins and up-regulation of expression of pro-apoptotic proteins. DCHA-HF treatment induced activation of the caspase 3, 8, and 9 cascade and subsequent PARP cleavage, and DCHA-HF-induced apoptosis was significantly inhibited by caspase inhibitors. Treated cells were arrested at the G1 phase of the cell cycle and the expression of p53 and p27(Kip1), two key regulators related to cell cycle and apoptosis, was up-regulated. These results suggest that DCHA-HF inhibits K562 cell growth by inducing caspase-dependent apoptosis mediated by a mitochondrial pathway and arresting the cell cycle at the G1 phase. Therefore, DCHA-HF is a potential chemotherapeutic antitumor drug for chronic myeloid leukemia therapy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

20(S)-Ginsenoside Rh2 Induce the Apoptosis and Autophagy in U937 and K562 Cells.

PubMed

Zhuang, Jianjian; Yin, Juxin; Xu, Chaojian; Mu, Ying; Lv, Shaowu

2018-03-08

Acute myeloid leukemia (AML) and Chronic myelogenous leukemia (CML) are common leukemia in adults. 20(S)-GRh2 is an important bioactive substance that is present in Panax ginseng. However, there are no investigations that deal with the comparison of apoptosis, the occurrence of autophagy, and the relationship between apoptosis and autophagy after being treated with 20(S)-GRh2 in AML and CML. In this study, we explored the effect of 20(S)-GRh2 on the AML and CML (U937 and K562). Fluorescence microscopy, CCK-8, Quantitative realtime PCR, Western blot, transmission electron microscopy (TEM), and flow cytometric analysis were used to detect the occurrence of cell proliferation inhibition, apoptosis, and autophagy. By using the above methods, it was determined that apoptosis induced by 20(S)-GRh2 was more obvious in K562 than U937 cells and 20(S)-GRh2 could generate autophagy in K562 and U937 cells. When pretreated by a specific inhibitor of autophagy, (3-methyladenine), the 20(S)-GRh2-induced apoptosis was enhanced, which indicated that 20(S)-GRh2-induced autophagy may protect U937 and K562 cells from undergoing apoptotic cell death. On the other hand, pretreated by an apoptosis suppressor (Z-VAD-FMK), it greatly induced the autophagy and partially prevented 20(S)-GRh2 induced apoptosis. This phenomenon indicated that 20(S)-GRh2-induced autophagy may serve as a survival mechanism and apoptosis and autophagy could act as partners to induce cell death in a cooperative manner. These findings may provide a rationale for future clinical application by using 20(S)-GRh2 combined autophagy inhibitors for AML and CML.

Time-series analysis in imatinib-resistant chronic myeloid leukemia K562-cells under different drug treatments.

PubMed

Zhao, Yan-Hong; Zhang, Xue-Fang; Zhao, Yan-Qiu; Bai, Fan; Qin, Fan; Sun, Jing; Dong, Ying

2017-08-01

Chronic myeloid leukemia (CML) is characterized by the accumulation of active BCR-ABL protein. Imatinib is the first-line treatment of CML; however, many patients are resistant to this drug. In this study, we aimed to compare the differences in expression patterns and functions of time-series genes in imatinib-resistant CML cells under different drug treatments. GSE24946 was downloaded from the GEO database, which included 17 samples of K562-r cells with (n=12) or without drug administration (n=5). Three drug treatment groups were considered for this study: arsenic trioxide (ATO), AMN107, and ATO+AMN107. Each group had one sample at each time point (3, 12, 24, and 48 h). Time-series genes with a ratio of standard deviation/average (coefficient of variation) >0.15 were screened, and their expression patterns were revealed based on Short Time-series Expression Miner (STEM). Then, the functional enrichment analysis of time-series genes in each group was performed using DAVID, and the genes enriched in the top ten functional categories were extracted to detect their expression patterns. Different time-series genes were identified in the three groups, and most of them were enriched in the ribosome and oxidative phosphorylation pathways. Time-series genes in the three treatment groups had different expression patterns and functions. Time-series genes in the ATO group (e.g. CCNA2 and DAB2) were significantly associated with cell adhesion, those in the AMN107 group were related to cellular carbohydrate metabolic process, while those in the ATO+AMN107 group (e.g. AP2M1) were significantly related to cell proliferation and antigen processing. In imatinib-resistant CML cells, ATO could influence genes related to cell adhesion, AMN107 might affect genes involved in cellular carbohydrate metabolism, and the combination therapy might regulate genes involved in cell proliferation.

Inhibition of Siah2 Ubiquitin Ligase by Vitamin K3 Attenuates Chronic Myeloid Leukemia Chemo-Resistance in Hypoxic Microenvironment.

PubMed

Huang, Jixian; Lu, Ziyuan; Xiao, Yajuan; He, Bolin; Pan, Chengyun; Zhou, Xuan; Xu, Na; Liu, Xiaoli

2018-02-05

BACKGROUND A hypoxic microenvironment is associated with resistance to tyrosine kinase inhibitors (TKIs) and a poor prognosis in chronic myeloid leukemia (CML). The E3 ubiquitin ligase Siah2 plays a vital role in the regulation of hypoxia response, as well as in leukemogenesis. However, the role of Siah2 in CML resistance is unclear, and it is unknown whether vitaminK3 (a Siah2 inhibitor) can improve the chemo-sensitivity of CML cells in a hypoxic microenvironment. MATERIAL AND METHODS The expression of Siah2 was detected in CML patients (CML-CP and CML-BC), K562 cells, and K562-imatinib-resistant cells (K562-R cells). We measured the expression of PHD3, HIF-1α, and VEGF in both cell lines under normoxia and hypoxic conditions, and the degree of leukemic sensitivity to imatinib and VitaminK3 were evaluated. RESULTS Siah2 was overexpressed in CML-BC patients (n=9) as compared to CML-CP patients (n=13). Similarly, K562-imatinib-resistant cells (K562-R cells) showed a significantly higher expression of Siah2 as compared to K562 cells in a hypoxic microenvironment. Compared to normoxia, under hypoxic conditions, both cell lines had lower PHD3, higher HIF-1α, and higher VEGF expression. Additionally, Vitamin K3 (an inhibitor of Siah2) reversed these changes and promoted a higher degree of leukemic sensitivity to imatinib. CONCLUSIONS Our findings indicate that the Siah2-PHD3- HIF-1α-VEGF axis is an important hypoxic signaling pathway in a leukemic microenvironment. An inhibitor of Siah2, combined with TKIs, might be a promising therapy for relapsing and refractory CML patients.

The cytotoxic action of the CD56+ fraction of cytokine-induced killer cells against a K562 cell line is mainly restricted to the natural killer cell subset.

PubMed

Chieregato, Katia; Zanon, Cristina; Castegnaro, Silvia; Bernardi, Martina; Amati, Eliana; Sella, Sabrina; Rodeghiero, Francesco; Astori, Giuseppe

2017-01-01

Cytokine-induced killer cells are polyclonal T cells generated ex vivo and comprise two main subsets: the CD56- fraction, possessing an alloreactive potential caused by T cells (CD3+CD56-), and the CD56+ fraction, characterised by a strong antitumour capacity induced by natural killer-like T cells (NK-like T, CD3+CD56+) and natural killer cells (NK, CD3-CD56+ bright). We investigated the cytotoxic action of selected CD56+ cell subpopulations against a human chronic myeloid leukaemia (K562) cell line. After immunomagnetic selection of the CD56+ cell fraction, NK bright cells (CD3-CD56+ bright) and two subsets of NK-like T cells (CD3+CD56+), called NK-like T CD56 dim and NK-like T CD56 bright, could be identified. The cytotoxic effect against K562 cells was mainly exerted by the NK bright subpopulation and resulted to be inversely correlated with the percentage of NK-like T CD56 dim cells in the culture. The lytic action appeared to be independent of cell degranulation as suggested by the lack of change in the expression of CD107a. We conclude that the cytotoxic action of CD56+ cells against a K562 cell line is mainly due to the NK cells.

Spontaneous cytotoxic earthworm leukocytes kill K562 tumor cells.

PubMed

Suzuki, M M; Cooper, E L

1995-08-01

Earthworm coelomocytes may act as effector cells which destroy targets in vitro. In a 51Cr release assay, Lumbricus coelomocyte effectors showed lytic activities of 3-14% against K562 human tumor cells when incubated 1-4 hr at 23 degrees C or 37 degrees C. Cytotoxicity was correlated with effector: target ratio. However, targets were not killed by incubating them in cell-free, 0.2 micron filtered coelomic fluid. The supernatant from coelomocytes cultured alone failed to kill K562 targets but coelomocyte lysates were toxic to target cells in a concentration-dependent manner. Coelomocytes were examined using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). When effectors and targets were examined under TEM, we found close apposition of effector granulocytic coelomocytes and target cell membranes but not with coelomocytes nor eleocytes at up to 15 min incubation. By SEM, effector cells appeared not only to be in close contact with targets, but instances of target lysis were observed. These results suggest that effector cell/target cell contact is essential for cytotoxicity to occur.

Mastic oil from Pistacia lentiscus var. chia inhibits growth and survival of human K562 leukemia cells and attenuates angiogenesis.

PubMed

Loutrari, Heleni; Magkouta, Sophia; Pyriochou, Anastasia; Koika, Vasiliki; Kolisis, Fragiskos N; Papapetropoulos, Andreas; Roussos, Charis

2006-01-01

Mastic oil from Pistacia lentiscus var. chia, a natural plant extract traditionally used as a food additive, has been extensively studied for its antimicrobial activity attributed to the combination of its bioactive components. One of them, perillyl alcohol (POH), displays tumor chemopreventive, chemotherapeutic, and antiangiogenic properties. We investigated whether mastic oil would also suppress tumor cell growth and angiogenesis. We observed that mastic oil concentration and time dependently exerted an antiproliferative and proapoptotic effect on K562 human leukemia cells and inhibited the release of vascular endothelial growth factor (VEGF) from K562 and B16 mouse melanoma cells. Moreover, mastic oil caused a concentration-dependent inhibition of endothelial cell (EC) proliferation without affecting cell survival and a significant decrease of microvessel formation both in vitro and in vivo. Investigation of underlying mechanism(s) demonstrated that mastic oil reduced 1) in K562 cells the activation of extracellular signal-regulated kinases 1/2 (Erk1/2) known to control leukemia cell proliferation, survival, and VEGF secretion and 2) in EC the activation of RhoA, an essential regulator of neovessel organization. Overall, our results underscore that mastic oil, through its multiple effects on malignant cells and ECs, may be a useful natural dietary supplement for cancer prevention.

Bardoxolone methyl (CDDO-Me or RTA402) induces cell cycle arrest, apoptosis and autophagy via PI3K/Akt/mTOR and p38 MAPK/Erk1/2 signaling pathways in K562 cells.

PubMed

Wang, Xin-Yu; Zhang, Xue-Hong; Peng, Li; Liu, Zheng; Yang, Yin-Xue; He, Zhi-Xu; Dang, Hong-Wan; Zhou, Shu-Feng

2017-01-01

Chronic myeloid leukemia (CML) treatment remains a challenge due to drug resistance and severe side effect, rendering the need on the development of novel therapeutics. CDDO-Me (Bardoxolone methyl), a potent Nrf2 activator and NF-κB inhibitor, is a promising candidate for cancer treatment including leukemia. However, the underlying mechanism for CDDO-Me in CML treatment is unclear. This study aimed to evaluate the molecular interactome of CDDO-Me in K562 cells using the quantitative proteomics approach stable-isotope labeling by amino acids in cell culture (SILAC) and explore the underlying mechanisms using cell-based functional assays. A total of 1,555 proteins responded to CDDO-Me exposure, including FANCI, SRPK2, XPO5, HP1BP3, NELFCD, Na + ,K + -ATPase 1, etc. in K562 cells. A total of 246 signaling pathways and 25 networks regulating cell survival and death, cellular function and maintenance, energy production, protein synthesis, response to oxidative stress, and nucleic acid metabolism were involved. Our verification experiments confirmed that CDDO-Me down-regulated Na + ,K + -ATPase α1 in K562 cells, and significantly arrested cells in G 2 /M and S phases, accompanied by remarkable alterations in the expression of key cell cycle regulators. CDDO-Me caused mitochondria-, death receptor-dependent and ER stress-mediated apoptosis in K562 cells, also induced autophagy with the suppression of PI3K/Akt/mTOR signaling pathway. p38 MAPK/Erk1/2 signaling pathways contributed to both apoptosis- and autophagy-inducing effects of CDDO-Me in K562 cells. Taken together, these data demonstrate that CDDO-Me is a potential anti-cancer agent that targets cell cycle, apoptosis, and autophagy in the treatment of CML.

Bardoxolone methyl (CDDO-Me or RTA402) induces cell cycle arrest, apoptosis and autophagy via PI3K/Akt/mTOR and p38 MAPK/Erk1/2 signaling pathways in K562 cells

PubMed Central

Wang, Xin-Yu; Zhang, Xue-Hong; Peng, Li; Liu, Zheng; Yang, Yin-Xue; He, Zhi-Xu; Dang, Hong-Wan; Zhou, Shu-Feng

2017-01-01

Chronic myeloid leukemia (CML) treatment remains a challenge due to drug resistance and severe side effect, rendering the need on the development of novel therapeutics. CDDO-Me (Bardoxolone methyl), a potent Nrf2 activator and NF-κB inhibitor, is a promising candidate for cancer treatment including leukemia. However, the underlying mechanism for CDDO-Me in CML treatment is unclear. This study aimed to evaluate the molecular interactome of CDDO-Me in K562 cells using the quantitative proteomics approach stable-isotope labeling by amino acids in cell culture (SILAC) and explore the underlying mechanisms using cell-based functional assays. A total of 1,555 proteins responded to CDDO-Me exposure, including FANCI, SRPK2, XPO5, HP1BP3, NELFCD, Na+,K+-ATPase 1, etc. in K562 cells. A total of 246 signaling pathways and 25 networks regulating cell survival and death, cellular function and maintenance, energy production, protein synthesis, response to oxidative stress, and nucleic acid metabolism were involved. Our verification experiments confirmed that CDDO-Me down-regulated Na+,K+-ATPase α1 in K562 cells, and significantly arrested cells in G2/M and S phases, accompanied by remarkable alterations in the expression of key cell cycle regulators. CDDO-Me caused mitochondria-, death receptor-dependent and ER stress-mediated apoptosis in K562 cells, also induced autophagy with the suppression of PI3K/Akt/mTOR signaling pathway. p38 MAPK/Erk1/2 signaling pathways contributed to both apoptosis- and autophagy-inducing effects of CDDO-Me in K562 cells. Taken together, these data demonstrate that CDDO-Me is a potential anti-cancer agent that targets cell cycle, apoptosis, and autophagy in the treatment of CML. PMID:29118925

The role of catechol-O-methyltransferase in catechol-enhanced erythroid differentiation of K562 cells.

PubMed

Suriguga; Li, Xiao-Fei; Li, Yang; Yu, Chun-Hong; Li, Yi-Ran; Yi, Zong-Chun

2013-12-15

Catechol is widely used in pharmaceutical and chemical industries. Catechol is also one of phenolic metabolites of benzene in vivo. Our previous study showed that catechol improved erythroid differentiation potency of K562 cells, which was associated with decreased DNA methylation in erythroid specific genes. Catechol is a substrate for the catechol-O-methyltransferase (COMT)-mediated methylation. In the present study, the role of COMT in catechol-enhanced erythroid differentiation of K562 cells was investigated. Benzidine staining showed that exposure to catechol enhanced hemin-induced hemoglobin accumulation and induced mRNA expression of erythroid specific genes in K562 cells. Treatment with catechol caused a time- and concentration-dependent increase in guaiacol concentration in the medium of cultured K562 cells. When COMT expression was knocked down by COMT shRNA expression in K562 cells, the production of guaiacol significantly reduced, and the sensitivity of K562 cells to cytotoxicity of catechol significantly increased. Knockdown of COMT expression by COMT shRNA expression also eliminated catechol-enhanced erythroid differentiation of K562 cells. In addition, the pre-treatment with methyl donor S-adenosyl-L-methionine or its demethylated product S-adenosyl-L-homocysteine induced a significant increase in hemin-induced Hb synthesis in K562 cells and the mRNA expression of erythroid specific genes. These findings indicated that O-methylation catalyzed by COMT acted as detoxication of catechol and involved in catechol-enhanced erythroid differentiation of K562 cells, and the production of S-adenosyl-L-homocysteine partly explained catechol-enhanced erythroid differentiation. © 2013.

Induced apoptosis by mild hyperthermia occurs via telomerase inhibition on the three human myeloid leukemia cell lines: TF-1, K562, and HL-60.

PubMed

Deezagi, Abdolkhaleg; Manteghi, Sanaz; Khosravani, Pardis; Vaseli-Hagh, Neda; Soheili, Zahra-Soheila

2009-09-01

The purpose of this research was to understand the effect of hyperthermia on the telomerase activity in human leukemic cell lines (HL-60, K562, and TF-1). The cells were treated by hyperthermia at the range of 41-44 degrees C for 120 min and incubated for 96 h. Then telomerase activity, cell proliferation, and apoptosis were assessed. The results indicated that hyperthermia significantly induced apoptosis on the cells. The cells exhibited pre-apoptotic pattern at 41 and 42 degrees C at 60-120 min and apoptotic pattern at 43 and 44 degrees C over 30 min after hyperthermia. Telomerase activity (that was assayed immediately after hyperthermia) was stable at 41-42 degrees C for 60 min but decreased to 35-40% at 120 min. However, at severe hyperthermia (43-44 degrees C) telomerase activity was decreased in a time- and dose-dependent manner. Following hyperthermia (41-44 degrees C up to 120 min), the cells were incubated for 96 h. In these conditions, the telomerase activity was decreased by about 60-80% in comparison with that untreated control cells.

VEGFR2-targeted fusion antibody improved NK cell-mediated immunosurveillance against K562 cells.

PubMed

Ren, Xueyan; Xie, Wei; Wang, Youfu; Xu, Menghuai; Liu, Fang; Tang, Mingying; Li, Chenchen; Wang, Min; Zhang, Juan

2016-08-01

MHC class I polypeptide-related sequence A (MICA), which is normally expressed on cancer cells, activates NK cells via NK group 2-member D pathway. However, some cancer cells escape NK-mediated immune surveillance by shedding membrane MICA causing immune suppression. To address this issue, we designed an antibody-MICA fusion targeting tumor-specific antigen (vascular endothelial growth factor receptor 2, VEGFR2) based on our patented antibody (mAb04) against VEGFR2. In vitro results demonstrate that the fusion antibody retains both the antineoplastic and the immunomodulatory activity of mAb04. Further, we revealed that it enhanced NK-mediated immunosurveillance against K562 cells through increasing degranulation and cytokine production of NK cells. The overall data suggest our new fusion protein provides a promising approach for cancer-targeted immunotherapy and has prospects for potential application of chronic myeloid leukemia.

The fusarin analogue NG-391 impairs nucleic acid formation in K-562 leukemia cells

USDA-ARS?s Scientific Manuscript database

The clavicipitaceous fungus Metarhizium robertsii produces the fusarin-like mycotoxin NG-391. We report on the biological effects of NG-391 on K-562 human cancer cells, obtained with radionuclide incorporation assays, along with nucleosome release and caspase assays, respectively. Our data suggests ...

The role of ROS in hydroquinone-induced inhibition of K562 cell erythroid differentiation.

PubMed

Yu, Chun Hong; Suriguga; Li, Yang; Li, Yi Ran; Tang, Ke Ya; Jiang, Liang; Yi, Zong Chun

2014-03-01

The role of ROS in hydroquinone-induced inhibition of K562 cell erythroid differentiation was investigated. After K562 cells were treated with hydroquinone for 24 h, and hemin was later added to induce erythroid differentiation for 48 h, hydroquinone inhibited hemin-induced hemoglobin synthesis and mRNA expression of γ-globin in K562 cells in a concentration-dependent manner. The 24-h exposure to hydroquinone also caused a concentration-dependent increase at an intracellular ROS level, while the presence of N- acetyl-L-cysteine prevented hydroquinone- induced ROS production in K562 cells. The presence of N-acetyl-L-cysteine also prevented hydroquinone inhibiting hemin-induced hemoglobin synthesis and mRNA expression of γ-globin in K562 cells. These evidences indicated that ROS production played a role in hydroquinone-induced inhibition of erythroid differentiation. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

The role of catechol-O-methyltransferase in catechol-enhanced erythroid differentiation of K562 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suriguga,; Li, Xiao-Fei; Li, Yang

2013-12-15

Catechol is widely used in pharmaceutical and chemical industries. Catechol is also one of phenolic metabolites of benzene in vivo. Our previous study showed that catechol improved erythroid differentiation potency of K562 cells, which was associated with decreased DNA methylation in erythroid specific genes. Catechol is a substrate for the catechol-O-methyltransferase (COMT)-mediated methylation. In the present study, the role of COMT in catechol-enhanced erythroid differentiation of K562 cells was investigated. Benzidine staining showed that exposure to catechol enhanced hemin-induced hemoglobin accumulation and induced mRNA expression of erythroid specific genes in K562 cells. Treatment with catechol caused a time- and concentration-dependentmore » increase in guaiacol concentration in the medium of cultured K562 cells. When COMT expression was knocked down by COMT shRNA expression in K562 cells, the production of guaiacol significantly reduced, and the sensitivity of K562 cells to cytotoxicity of catechol significantly increased. Knockdown of COMT expression by COMT shRNA expression also eliminated catechol-enhanced erythroid differentiation of K562 cells. In addition, the pre-treatment with methyl donor S-adenosyl-L-methionine or its demethylated product S-adenosyl-L-homocysteine induced a significant increase in hemin-induced Hb synthesis in K562 cells and the mRNA expression of erythroid specific genes. These findings indicated that O-methylation catalyzed by COMT acted as detoxication of catechol and involved in catechol-enhanced erythroid differentiation of K562 cells, and the production of S-adenosyl-L-homocysteine partly explained catechol-enhanced erythroid differentiation. - Highlights: • Catechol enhanced hemin-induced hemoglobin accumulation. • COMT-catalyzed methylation acted as detoxication of catechol. • COMT involved in catechol-enhanced erythroid differentiation.« less

Kinetics of ultraweak light emission from human erythroleukemia K562 cells upon electroporation.

PubMed

Maccarrone, M; Fantini, C; Agrò, A F; Rosato, N

1998-11-11

Electroporation involves the application of an electric pulse that creates transient aqueous channels (electropores) across the lipid bilayer membranes. Here, we describe an instrument set up suitable to record ultraweak light emission from human erythroleukemia K562 cells during and immediately after delivery of electric pulses. Most of light was emitted in the first seconds after each pulse, following a complex decay which can be fitted by a double exponential equation characterized by two different time constants (T1 and T2), both in the order of seconds. T1 was approximately 10-fold shorter than T2 and both time constants were dependent on field strength of the electric pulse. The effect of various antioxidants on the amount of emitted photons and on T1 and T2 values was investigated, in order to shed some light on the chemical species responsible for cellular luminescence.

Small Molecule TH-39 Potentially Targets Hec1/Nek2 Interaction and Exhibits Antitumor Efficacy in K562 Cells via G0/G1 Cell Cycle Arrest and Apoptosis Induction.

PubMed

Zhu, Yongxia; Wei, Wei; Ye, Tinghong; Liu, Zhihao; Liu, Li; Luo, Yong; Zhang, Lidan; Gao, Chao; Wang, Ningyu; Yu, Luoting

2016-01-01

Cancer is still a major public health issue worldwide, and new therapeutics with anti-tumor activity are still urgently needed. The anti-tumor activity of TH-39, which shows potent anti-proliferative activity against K562 cells with an IC50 of 0.78 µM, was investigated using immunoblot, co-immunoprecipitation, the MTT assay, and flow cytometry. Mechanistically, TH-39 may disrupt the interaction between Hec1 and Nek2 in K562 cells. Moreover, TH-39 inhibited cell proliferation in a concentration- and time-dependent manner by influencing the morphology of K562 cells and inducing G0/G1 phase arrest. G0/G1 phase arrest was associated with down-regulation of CDK2-cyclin E complex and CDK4/6-cyclin D complex activities. Furthermore, TH-39 also induced cell apoptosis, which was associated with activation of caspase-3, down-regulation of Bcl-2 expression and up-regulation of Bax. TH-39 could also decrease mitochondrial membrane potential (Δψm) and increase reactive oxygen species (ROS) accumulation in K562 cells. The results indicated that TH-39 might induce apoptosis via the ROS-mitochondrial apoptotic pathway. This study highlights the potential therapeutic efficacy of the anti-cancer compound TH-39 in treatment-resistant chronic myeloid leukemia. © 2016 The Author(s) Published by S. Karger AG, Basel.

Knockdown of HOXA10 reverses the multidrug resistance of human chronic mylogenous leukemia K562/ADM cells by downregulating P-gp and MRP-1.

PubMed

Yi, Ying-Jie; Jia, Xiu-Hong; Wang, Jian-Yong; Li, You-Jie; Wang, Hong; Xie, Shu-Yang

2016-05-01

Multidrug resistance (MDR) of leukemia cells is a major obstacle in chemotherapeutic treatment. The high expression and constitutive activation of P-glycoprotein (P-gp) and multidrug resistance protein-1 (MRP-1) have been reported to play a vital role in enhancing cell resistance to anticancer drugs in many tumors. The present study aimed to investigate the reversal of MDR by silencing homeobox A10 (HOXA10) in adriamycin (ADR)-resistant human chronic myelogenous leukemia (CML) K562/ADM cells by modulating the expression of P-gp and MRP-1. K562/ADM cells were stably transfected with HOXA10-targeted short hairpin RNA (shRNA). The results of reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis showed that the mRNA and protein expression of HOXA10 was markedly suppressed following transfection with a shRNA-containing vector. The sensitivity of the K562/ADM cells to ADR was enhanced by the silencing of HOXA10, due to the increased intracellular accumulation of ADR. The accumulation of ADR induced by the silencing of HOXA10 may be due to the downregulation of P-gp and MRP-1. Western blot analysis revealed that downregulating HOXA10 inhibited the protein expression of P-gp and MRP-1. Taken together, these results suggest that knockdown of HOXA10 combats resistance and that HOXA10 is a potential target for resistant human CML.

Quinacrine induces apoptosis in human leukemia K562 cells via p38 MAPK-elicited BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Changchien, Jung-Jung; Chen, Ying-Jung; Huang, Chia-Hui

2015-04-01

Although previous studies have revealed the anti-cancer activity of quinacrine, its effect on leukemia is not clearly resolved. We sought to explore the cytotoxic effect and mechanism of quinacrine action in human leukemia K562 cells. Quinacrine induced K562 cell apoptosis accompanied with ROS generation, mitochondrial depolarization, and down-regulation of BCL2L1 and BCL2. Upon exposure to quinacrine, ROS-mediated p38 MAPK activation and ERK inactivation were observed in K562 cells. Quinacrine-induced cell death and mitochondrial depolarization were suppressed by the p38MAPK inhibitor SB202190 and constitutively active MEK1 over-expression. Activation of p38 MAPK was shown to promote BCL2 degradation. Further, ERK inactivation suppressedmore » c-Jun-mediated transcriptional expression of BCL2L1. Over-expression of BCL2L1 and BCL2 attenuated quinacrine-evoked mitochondrial depolarization and rescued the viability of quinacrine-treated cells. Taken together, our data indicate that quinacrine-induced K562 cell apoptosis is mediated through mitochondrial alterations triggered by p38 MAPK-mediated BCL2 down-regulation and suppression of ERK/c-Jun-mediated BCL2L1 expression. - Highlights: • Quinacrine induces K562 cell apoptosis via down-regulation of BCL2 and BCL2L1. • Quinacrine induces p38 MAPK activation and ERK inactivation in K562 cells. • Quinacrine elicits p38 MAPK-mediated BCL2 down-regulation. • Quinacrine suppresses ERK/c-Jun-mediated BCL2L1 expression.« less

Expression of bovine non-classical major histocompatibility complex class I proteins in mouse P815 and human K562 cells.

PubMed

Parasar, Parveen; Wilhelm, Amanda; Rutigliano, Heloisa M; Thomas, Aaron J; Teng, Lihong; Shi, Bi; Davis, William C; Suarez, Carlos E; New, Daniel D; White, Kenneth L; Davies, Christopher J

2016-08-01

Major histocompatibility complex class I (MHC-I) proteins can be expressed as cell surface or secreted proteins. To investigate whether bovine non-classical MHC-I proteins are expressed as cell surface or secreted proteins, and to assess the reactivity pattern of monoclonal antibodies with non-classical MHC-I isoforms, we expressed the MHC proteins in murine P815 and human K562 (MHC-I deficient) cells. Following antibiotic selection, stably transfected cell lines were stained with H1A or W6/32 antibodies to detect expression of the MHC-I proteins by flow cytometry. Two non-classical proteins (BoLA-NC1*00501 and BoLA-NC3*00101) were expressed on the cell surface in both cell lines. Surprisingly, the BoLA-NC4*00201 protein was expressed on the cell membrane of human K562 but not mouse P815 cells. Two non-classical proteins (BoLA-NC1*00401, which lacks a transmembrane domain, and BoLA-NC2*00102) did not exhibit cell surface expression. Nevertheless, Western blot analyses demonstrated expression of the MHC-I heavy chain in all transfected cell lines. Ammonium-sulfate precipitation of proteins from culture supernatants showed that BoLA-NC1*00401 was secreted and that all surface expressed proteins where shed from the cell membrane by the transfected cells. Interestingly, the surface expressed MHC-I proteins were present in culture supernatants at a much higher concentration than BoLA-NC1*00401. This comprehensive study shows that bovine non-classical MHC-I proteins BoLA-NC1*00501, BoLA-NC3*00101, and BoLA-NC4*00201 are expressed as surface isoforms with the latter reaching the cell membrane only in K562 cells. Furthermore, it demonstrated that BoLA-NC1*00401 is a secreted isoform and that significant quantities of membrane associated MHC-I proteins can be shed from the cell membrane. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Osthole shows the potential to overcome P-glycoprotein‑mediated multidrug resistance in human myelogenous leukemia K562/ADM cells by inhibiting the PI3K/Akt signaling pathway.

PubMed

Wang, Hong; Jia, Xiu-Hong; Chen, Jie-Ru; Wang, Jian-Yong; Li, You-Jie

2016-06-01

P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) has been reported to play a pivotal role in tumor chemotherapy failure. Study after study has illustrated that the phosphoinositide 3-kinase (PI3K)/Akt signaling cascade is involved in the MDR phenotype and is correlated with P-gp expression in many human malignancies. In the present study, osthole, an O-methylated coumarin, exhibited potent reversal capability of MDR in myelogenous leukemia K562/ADM cells. Simultaneously, the uptake and efflux of Rhodamine-123 (Rh-123) and the accumulation of doxorubicin assays combined with flow cytometric analysis suggested that osthole could increase intracellular drug accumulation. Furthermore, osthole decreased the expression of multidrug resistance gene 1 (MDR1) at both the mRNA and protein levels. Further experiments elucidated that osthole could suppress P-gp expression by inhibiting the PI3K/Akt signaling pathway which might be the main mechanism accounting for the reversal potential of osthole in the MDR in K562/ADM cells. In conclusion, osthole combats MDR and could be a promising candidate for the development of novel MDR reversal modulators.

Involvement of p38 MAPK- and JNK-modulated expression of Bcl-2 and Bax in Naja nigricollis CMS-9-induced apoptosis of human leukemia K562 cells.

PubMed

Chen, Ying-Jung; Liu, Wen-Hsin; Kao, Pei-Hsiu; Wang, Jeh-Jeng; Chang, Long-Sen

2010-06-15

CMS-9, a phospholipase A(2) (PLA(2)) isolated from Naja nigricollis venom, induced apoptosis of human leukemia K562 cells, characterized by mitochondrial depolarization, modulation of Bcl-2 family members, cytochrome c release and activation of caspases 9 and 3. Moreover, an increase in intracellular Ca2+ concentration and the production of reactive oxygen species (ROS) was noted. Pretreatment with BAPTA-AM (Ca2+ chelator) and N-acetylcysteine (NAC, ROS scavenger) proved that Ca2+ was an upstream event in inducing ROS generation. Upon exposure to CMS-9, activation of p38 MAPK and JNK was observed in K562 cells. BAPTA-AM or NAC abrogated CMS-9-elicited p38 MAPK and JNK activation, and rescued viability of CMS-9-treated K562 cells. SB202190 (p38 MAPK inhibitor) and SP600125 (JNK inhibitor) suppressed CMS-9-induced dissipation of mitochondrial membrane potential, Bcl-2 down-regulation, Bax up-regulation and increased mitochondrial translocation of Bax. Inactivation of PLA(2) activity reduced drastically the cytotoxicity of CMS-9, and a combination of lysophosphatidylcholine and stearic acid mimicked the cytotoxic effects of CMS-9. Taken together, our data suggest that CMS-9-induced apoptosis of K562 cells is catalytic activity-dependent and is mediated through mitochondria-mediated death pathway triggered by Ca2+/ROS-evoked p38 MAPK and JNK activation. 2010 Elsevier Ltd. All rights reserved.

Oxidative stress by ascorbate/menadione association kills K562 human chronic myelogenous leukaemia cells and inhibits its tumour growth in nude mice.

PubMed

Verrax, Julien; Stockis, Julie; Tison, Aurélie; Taper, Henryk S; Calderon, Pedro Buc

2006-09-14

The effect of oxidative stress induced by the ascorbate/menadione-redox association was examined in K562 cells, a human erythromyeloid leukaemia cell line. Our results show that ascorbate enhances menadione redox cycling, leading to the formation of intracellular reactive oxygen species (as shown by dihydrorhodamine 123 oxidation). The incubation of cells in the presence of both ascorbate/menadione and aminotriazole, a catalase inhibitor, resulted in a strong decrease of cell survival, reinforcing the role of H(2)O(2) as the main oxidizing agent killing K562 cells. This cell death was not caspase-3-dependent. Indeed, neither procaspase-3 and PARP were processed and only a weak cytochrome c release was observed. Moreover, we observed only 23% of cells with depolarized mitochondria. In ascorbate/menadione-treated cells, DNA fragmentation was observed without any sign of chromatin condensation (DAPI and TUNEL tests). The cell demise by ascorbate/menadione is consistent with a necrosis-like cell death confirmed by both cytometric profile of annexin-V/propidium iodide labeled cells and by light microscopy examination. Finally, we showed that a single i.p. administration of the association of ascorbate and menadione is able to inhibit the growth of K562 cells by about 60% (in both tumour size and volume) in an immune-deficient mice model. Taken together, these results reinforced our previous claims about a potential application of the ascorbate/menadione association in cancer therapy.

Different toxic effects of YTX in tumor K-562 and lymphoblastoid cell lines

PubMed Central

Fernández-Araujo, Andrea; Sánchez, Jon A.; Alfonso, Amparo; Vieytes, Mercedes R.; Botana, Luis M.

2015-01-01

Yessotoxin (YTX) modulates cellular phosphodiesterases (PDEs). In this regard, opposite effects had been described in the tumor model K-562 cell line and fresh human lymphocytes in terms of cell viability, cyclic adenosine 3',5'-cyclic monophosphate (cAMP) production and protein expression after YTX treatment. Studies in depth of the pathways activated by YTX in K-562 cell line, have demonstrated the activation of two different cell death types, apoptosis, and autophagy after 24 and 48 h of treatment, respectively. Furthermore, the key role of type 4A PDE (PDE4A) in both pathways activated by YTX was demonstrated. Therefore, taking into account the differences between cellular lines and fresh cells, a study of cell death pathways activated by YTX in a non-tumor cell line with mitotic activity, was performed. The cellular model used was the lymphoblastoid cell line that represents a non-tumor model with normal apoptotic and mitotic machinery. In this context, cell viability and cell proliferation, expression of proteins involved in cell death activated by YTX and mitochondrial mass, were studied after the incubation with the toxin. Opposite to the tumor model, no cell death activation was observed in lymphoblastoid cell line in the presence of YTX. In this sense, variations in apoptosis hallmarks were not detected in the lymphoblastoid cell line after YTX incubation, whereas this type I of programmed cell death was observed in K-562 cells. On the other hand, autophagy cell death was triggered in this cellular line, while other autophagic process is suggested in lymphoblastoid cells. These YTX effects are related to PDE4A in both cellular lines. In addition, while cell death is triggered in K-562 cells after YTX treatment, in lymphoblastoid cells the toxin stops cellular proliferation. These results point to YTX as a specific toxic compound of tumor cells, since in the non-tumor lymphoblastoid cell line, no cell death hallmarks are observed. PMID:26136685

Effectiveness of imatinib mesylate over etoposide in the treatment of sensitive and resistant chronic myeloid leukaemia cells in vitro.

PubMed

Husaini, Roslina; Ahmad, Munirah; Zakaria, Zubaidah

2017-06-01

Chronic myeloid leukaemia (CML) is a form of leukaemia derived from the myeloid cell lineage. Imatinib mesylate, the breakpoint cluster region-abelson murine leukeamia kinase inhibitor, is a specific reagent used in the clinical treatment of CML. The DNA topoisomerase II inhibitor, etoposide, is also employed as a therapeutic, though it is used to a lesser extent. The present study aims to evaluate the effects of CML-targeted therapy, utilising imatinib mesylate and etoposide in the in vitro treatment of parental sensitive and adriamycin-resistant CML in the K562 and K562/ADM cell lines, respectively. Preliminary work involved the screening of multidrug resistant (MDR) gene expression, including MDR1, MRP1 and B-cell lymphoma 2 (BCL-2) at the mRNA levels. The sensitive and resistant CML cell lines expressed the MRP1 gene, though the sensitive K562 cells expressed low, almost undetectable levels of MDR1 and BCL-2 genes relative to the K562/ADM cells. Following treatment with imatinib mesylate or etoposide, the IC50 for imatinib mesylate did not differ between the sensitive and resistant cell lines (0.492±0.024 and 0.378±0.029, respectively), indicating that imatinib mesylate is effective in the treatment of CML regardless of cell chemosensitivity. However, the IC50 for etoposide in sensitive K562 cells was markedly lower than that of K562/ADM cells (50.6±16.5 and 194±8.46 µM, respectively), suggesting that the higher expression levels of MDR1 and/or BCL-2 mRNA in resistant cells may be partially responsible for this effect. This is supported by terminal deoxynucleotidyl transferase dUTP nick-end labeling data, whereby a higher percentage of apoptotic cells were found in the sensitive and resistant K562 cells treated with imatinib mesylate (29.3±0.2 and 31.9±16.7%, respectively), whereas etoposide caused significant apoptosis of sensitive K562 cells (18.3±8.35%) relative to K562/ADM cells (5.17±3.3%). In addition, the MDR genes in K562/ADM cells were knocked

Synthesis of a Novel Series of 2-Methylsulfanyl Fatty Acids and their Toxicity on the Human K-562 and U-937 Leukemia Cell Lines

PubMed Central

Carballeira, Néstor M.; Miranda, Carlos; Orellano, Elsie A.; González, Fernando A.

2006-01-01

The hitherto unknown 2-methylsulfanyldecanoic acid and 2-methylsulfanyldodecanoic acid were synthesized from methyl decanoate and methyl dodecanoate, respectively, through the reaction of lithium diisopropylamide and dimethyldisulfide in THF followed by saponification with potassium hydroxide in ethanol. Both α-methylsulfanylated FA were cytotoxic to the human chronic myelogenous leukemia K-562 and the human histiocytic lymphoma U-937 cell lines with EC50 values in the 200-300 μM range, which makes them more cytotoxic to these cell lines than either decanoic acid or dodecanoic acid. The cytotoxicity of the studied FA towards K-562 followed the order: 2-SCH3-12:0 > 2-SCH3-10:0 > 10:0 > 12:0 > 2-OCH3-12:0, while towards U-937 the cytotoxicity was found to be: 2-SCH3-10:0 > 2-SCH3-12:0 > 12:0 > 10:0 > 2-OCH3-12:0. These results indicate that the α-methylsulfanyl substitution increases the cytotoxicity of the C10 and C12 fatty acids towards the studied leukemia cell lines. PMID:16382579

The role of DNA methylation in catechol-enhanced erythroid differentiation of K562 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xiao-Fei; Wu, Xiao-Rong; Xue, Ming

2012-11-15

Catechol is one of phenolic metabolites of benzene in vivo. Catechol is also widely used in pharmaceutical and chemical industries. In addition, fruits, vegetables and cigarette smoke also contain catechol. Our precious study showed that several benzene metabolites (phenol, hydroquinone, and 1,2,4-benzenetriol) inhibited erythroid differentiation of K562 cells. In present study, the effect of catechol on erythroid differentiation of K562 cells was investigated. Moreover, to address the role of DNA methylation in catechol-induced effect on erythroid differentiation in K562 cells, methylation levels of erythroid-specific genes were analyzed by Quantitative MassARRAY methylation analysis platform. Benzidine staining showed that exposure to catecholmore » enhanced hemin-induced hemoglobin accumulation in K562 cells in concentration- and time-dependent manners. The mRNA expression of erythroid specific genes, including α-globin, β-globin, γ-globin, erythroid 5-aminolevulinate synthase, erythroid porphobilinogen deaminase, and transcription factor GATA-1 genes, showed a significant concentration-dependent increase in catechol-treated K562 cells. The exposure to catechol caused a decrease in DNA methylation levels at a few CpG sites in some erythroid specific genes including α-globin, β-globin and erythroid porphobilinogen deaminase genes. These results indicated that catechol improved erythroid differentiation potency of K562 cells at least partly via up-regulating transcription of some erythroid related genes, and suggested that inhibition of DNA methylation might be involved in up-regulated expression of some erythroid related genes. -- Highlights: ► Catechol enhanced hemin-induced hemoglobin accumulation. ► Exposure to catechol resulted in up-regulated expression of erythroid genes. ► Catechol reduced methylation levels at some CpG sites in erythroid genes.« less

Vaccination with autologous myeloblasts admixed with GM-K562 cells in patients with advanced MDS or AML after allogeneic HSCT

PubMed Central

Kim, Haesook T.; Bavli, Natalie; Mihm, Martin; Pozdnyakova, Olga; Piesche, Matthias; Daley, Heather; Reynolds, Carol; Souders, Nicholas C.; Cutler, Corey; Koreth, John; Alyea, Edwin P.; Antin, Joseph H.; Ritz, Jerome; Dranoff, Glenn; Soiffer, Robert J.

2017-01-01

We report a clinical trial testing vaccination of autologous myeloblasts admixed with granulocyte-macrophage colony-stimulating factor secreting K562 cells after allogeneic hematopoietic stem cell transplantation (HSCT). Patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) with ≥5% marrow blasts underwent myeloblast collection before HSCT. At approximately day +30, 6 vaccines composed of irradiated autologous myeloblasts mixed with GM-K562 were administered. Tacrolimus-based graft-versus-host disease (GVHD) prophylaxis was not tapered until vaccine completion (∼day 100). Thirty-three patients with AML (25) and MDS (8) enrolled, 16 (48%) had ≥5% marrow blasts at transplantation. The most common vaccine toxicity was injection site reactions. One patient developed severe eosinophilia and died of eosinophilic myocarditis. With a median follow-up of 67 months, cumulative incidence of grade 2-4 acute and chronic GVHD were 24% and 33%, respectively. Relapse and nonrelapse mortality were 48% and 9%, respectively. Progression-free survival (PFS) and overall survival (OS) at 5 years were 39% and 39%. Vaccinated patients who were transplanted with active disease (≥5% marrow blasts) had similar OS and PFS at 5 years compared with vaccinated patients transplanted with <5% marrow blasts (OS, 44% vs 35%, respectively, P = .81; PFS, 44% vs 35%, respectively, P = .34). Postvaccination antibody responses to angiopoietin-2 was associated with superior OS (hazard ratio [HR], 0.43; P = .031) and PFS (HR, 0.5; P = .036). Patients transplanted with active disease had more frequent angiopoeitin-2 antibody responses (62.5% vs 20%, P = .029) than those transplanted in remission. GM-K562/leukemia cell vaccination induces biologic activity, even in patients transplanted with active MDS/AML. This study is registered at www.clinicaltrials.gov as #NCT 00809250. PMID:29296875

Celecoxib sensitizes imatinib-resistant K562 cells to imatinib by inhibiting MRP1-5, ABCA2 and ABCG2 transporters via Wnt and Ras signaling pathways.

PubMed

Dharmapuri, Gangappa; Doneti, Ravinder; Philip, Gundala Harold; Kalle, Arunasree M

2015-07-01

Imatinib mesylate, a tyrosine kinase inhibitor, is very effective in the treatment of chronic myeloid leukemia (CML). However, development of resistance to imatinib therapy is also a very common mechanism observed with long-term administration of the drug. Our previous studies have highlighted the role of cyclooxygenase-2 (COX-2) in regulating the expression of multidrug resistant protein-1 (MDR1), P-gp, in imatinib-resistant K562 cells (IR-K562) via PGE2-cAMP-PKC-NF-κB pathway and inhibition of COX-2 by celecoxib, a COX-2 specific inhibitor, inhibits this pathway and reverses the drug resistance. Studies have identified that not only MDR1 but other ATP-binding cassette transport proteins (ABC transporters) are involved in the development of imatinib resistance. Here, we tried to study the role of COX-2 in the regulation of other ABC transporters such as MRP1, MRP2, MRP3, ABCA2 and ABCG2 that have been already implicated in imatinib resistance development. The results of the study clearly indicated that overexpression of COX-2 lead to upregulation of MRP family proteins in IR-K562 cells and celecoxib down-regulated the ABC transporters through Wnt and MEK signaling pathways. The study signifies that celecoxib in combination with the imatinib can be a good alternate treatment strategy for the reversal of imatinib resistance. Copyright © 2015 Elsevier Ltd. All rights reserved.

Diverse Effects of Glutathione and UPF Peptides on Antioxidant Defense System in Human Erythroleukemia Cells K562.

PubMed

Kairane, Ceslava; Mahlapuu, Riina; Ehrlich, Kersti; Kilk, Kalle; Zilmer, Mihkel; Soomets, Ursel

2012-01-01

The main goal of the present paper was to examine the influence of the replacement of γ-Glu moiety to α-Glu in glutathione and in its antioxidative tetrapeptidic analogue UPF1 (Tyr(Me)-γ-Glu-Cys-Gly), resulting in α-GSH and UPF17 (Tyr(Me)-Glu-Cys-Gly), on the antioxidative defense system in K562 cells. UPF1 and GSH increased while UPF17 and α-GSH decreased the activity of CuZnSOD in K562 cells, at peptide concentration of 10 μM by 42% and 38% or 35% and 24%, respectively. After three-hour incubation, UPF1 increased and UPF17 decreased the intracellular level of total GSH. Additionally, it was shown that UPF1 is not degraded by γ-glutamyltranspeptidase, which performs glutathione breakdown. These results indicate that effective antioxidative character of peptides does not depend only on the reactivity of the thiol group, but also of the other functional groups, and on the spatial structure of peptides.

Electrochemical K-562 cells sensor based on origami paper device for point-of-care testing.

PubMed

Ge, Shenguang; Zhang, Lina; Zhang, Yan; Liu, Haiyun; Huang, Jiadong; Yan, Mei; Yu, Jinghua

2015-12-01

A low-cost, simple, portable and sensitive paper-based electrochemical sensor was established for the detection of K-562 cell in point-of-care testing. The hybrid material of 3D Au nanoparticles/graphene (3D Au NPs/GN) with high specific surface area and ionic liquid (IL) with widened electrochemical windows improved the good biocompatibility and high conductivity was modified on paper working electrode (PWE) by the classic assembly method and then employed as the sensing surface. IL could not only enhance the electron transfer ability but also provide sensing recognition interface for the conjugation of Con A with cells, with the cell capture efficiency and the sensitivity of biosensor strengthened simultaneously. Concanavalin A (Con A) immobilization matrix was used to capture cells. As proof-of-concept, the paper-based electrochemical sensor for the detection of K-562 cells was developed. With such sandwich-type assay format, K-562 cells as model cells were captured on the surface of Con A/IL/3D AuNPs@GN/PWE. Con A-labeled dendritic PdAg NPs were captured on the surface of K-562 cells. Such dendritic PdAg NPs worked as catalysts promoting the oxidation of thionine (TH) by H2O2 which was released from K-562 cells via the stimulation of phorbol 12-myristate-13-acetate (PMA). Therefore, the current signal response was dependent on the amount of PdAg NPs and the concentration of H2O2, the latter of which corresponded with the releasing amount from cells. So, the detection method of K-562 cell was also developed. Under optimized experimental conditions, 1.5×10(-14) mol of H2O2 releasing from each cell was calculated. The linear range and the detection limit for K-562 cells were determined to be 1.0×10(3)-5.0×10(6) cells/mL and 200 cells/mL, respectively. Such as-prepared sensor showed excellent analytical performance with good fabrication reproducibility, acceptable precision and satisfied accuracy, providing a novel protocol in point-of-care testing of cells

Olive (Olea europaea) Leaf Extract Induces Apoptosis and Monocyte/Macrophage Differentiation in Human Chronic Myelogenous Leukemia K562 Cells: Insight into the Underlying Mechanism

PubMed Central

Han, Junkyu; Jlaiel, Lobna; Sayadi, Sami; Isoda, Hiroko

2014-01-01

Differentiation therapy is an attractive approach aiming at reversing malignancy and reactivating endogenous differentiation programs in cancer cells. Olive leaf extract, known for its antioxidant activity, has been demonstrated to induce apoptosis in several cancer cells. However, its differentiation inducing properties and the mechanisms involved are still poorly understood. In this study, we investigated the effect of Chemlali Olive Leaf Extract (COLE) for its potential differentiation inducing effect on multipotent leukemia K562 cells. Results showed that COLE inhibits K562 cells proliferation and arrests the cell cycle at G0/G1, and then at G2/M phase over treatment time. Further analysis revealed that COLE induces apoptosis and differentiation of K562 cells toward the monocyte lineage. Microarray analysis was conducted to investigate the underlying mechanism of COLE differentiation inducing effect. The differentially expressed genes such as IFI16, EGR1, NFYA, FOXP1, CXCL2, CXCL3, and CXCL8 confirmed the commitment of K562 cells to the monocyte/macrophage lineage. Thus our results provide evidence that, in addition to apoptosis, induction of differentiation is one of the possible therapeutic effects of olive leaf in cancer cells. PMID:24803988

Olive (Olea europaea) leaf extract induces apoptosis and monocyte/macrophage differentiation in human chronic myelogenous leukemia K562 cells: insight into the underlying mechanism.

PubMed

Samet, Imen; Han, Junkyu; Jlaiel, Lobna; Sayadi, Sami; Isoda, Hiroko

2014-01-01

Differentiation therapy is an attractive approach aiming at reversing malignancy and reactivating endogenous differentiation programs in cancer cells. Olive leaf extract, known for its antioxidant activity, has been demonstrated to induce apoptosis in several cancer cells. However, its differentiation inducing properties and the mechanisms involved are still poorly understood. In this study, we investigated the effect of Chemlali Olive Leaf Extract (COLE) for its potential differentiation inducing effect on multipotent leukemia K562 cells. Results showed that COLE inhibits K562 cells proliferation and arrests the cell cycle at G0/G1, and then at G2/M phase over treatment time. Further analysis revealed that COLE induces apoptosis and differentiation of K562 cells toward the monocyte lineage. Microarray analysis was conducted to investigate the underlying mechanism of COLE differentiation inducing effect. The differentially expressed genes such as IFI16, EGR1, NFYA, FOXP1, CXCL2, CXCL3, and CXCL8 confirmed the commitment of K562 cells to the monocyte/macrophage lineage. Thus our results provide evidence that, in addition to apoptosis, induction of differentiation is one of the possible therapeutic effects of olive leaf in cancer cells.

Voltage-Gated K+ Channel, Kv3.3 Is Involved in Hemin-Induced K562 Differentiation

PubMed Central

Song, Min Seok; Choi, Seon Young; Ryu, Pan Dong; Lee, So Yeong

2016-01-01

Voltage-gated K+ (Kv) channels are well known to be involved in cell proliferation. However, even though cell proliferation is closely related to cell differentiation, the relationship between Kv channels and cell differentiation remains poorly investigated. This study demonstrates that Kv3.3 is involved in K562 cell erythroid differentiation. Down-regulation of Kv3.3 using siRNA-Kv3.3 increased hemin-induced K562 erythroid differentiation through decreased activation of signal molecules such as p38, cAMP response element-binding protein, and c-fos. Down-regulation of Kv3.3 also enhanced cell adhesion by increasing integrin β3 and this effect was amplified when the cells were cultured with fibronectin. The Kv channels, or at least Kv3.3, appear to be associated with cell differentiation; therefore, understanding the mechanisms of Kv channel regulation of cell differentiation would provide important information regarding vital cellular processes. PMID:26849432

DNA damage, lysosomal degradation and Bcl-xL deamidation in doxycycline- and minocycline-induced cell death in the K562 leukemic cell line.

PubMed

Fares, Mona; Abedi-Valugerdi, Manuchehr; Hassan, Moustapha; Potácová, Zuzana

2015-07-31

We investigated mechanisms of cytotoxicity induced by doxycycline (doxy) and minocycline (mino) in the chronic myeloid leukemia K562 cell line. Doxy and mino induced cell death in exposure-dependent manner. While annexin V/propidium iodide staining was consistent with apoptosis, the morphological changes in Giemsa staining were more equivocal. A pancaspase inhibitor Z-VAD-FMK partially reverted cell death morphology, but concurrently completely prevented PARP cleavage. Mitochondrial involvement was detected as dissipation of mitochondrial membrane potential and cytochrome C release. DNA double strand breaks detected with γH2AX antibody and caspase-2 activation were found early after the treatment start, but caspase-3 activation was a late event. Decrement of Bcl-xL protein levels and electrophoretic shift of Bcl-xL molecule were induced by both drugs. Phosphorylation of Bcl-xL at serine 62 was ruled out. Similarly, Bcr/Abl tyrosine kinase levels were decreased. Lysosomal inhibitor chloroquine restored Bcl-xL and Bcr/Abl protein levels and inhibited caspase-3 activation. Thus, the cytotoxicity of doxy and mino in K562 cells is mediated by DNA damage, Bcl-xL deamidation and lysosomal degradation with activation of mitochondrial pathway of apoptosis. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Research on the effect of formononetin on photodynamic therapy in K562 cells.

PubMed

Sun, Dan; Lu, Yao; Zhang, Su-Juan; Wang, Kai-Ge; Sun, Zhe

2017-10-01

At the present time, many cancer patients combine some forms of complementary and alternative medicine therapies with their conventional therapies. The most common choice of these therapies is the use of antioxidants. Formononetin is presented in different foods. It has a variety of biological activities including antioxidant and anti-cancer properties. On account of its antioxidant activity, formononetin might protect cancer cells from free radical damage in photodynamic therapy (PDT) during which reactive oxygen species (ROS) production was stimulated leading to irreversible tumor cell injury. In this study, the influence of formononetin on K562 cells in PDT was demonstrated. The results showed that formononetin supplementation alone did not affect the lipid peroxidation, DNA damage and apoptosis in K562 cells. It increases the lipid peroxidation, DNA damage and apoptosis in K562 cells induced by PDT. The singlet oxygen quencher sodium azide suppresses the apoptosis induced by PDT with formononetin. In conclusion, formononetin consumption during PDT increases the effectiveness of cancer therapy on malignant cells. The effect of antioxidants on PDT maybe was determined by its sensitization ability to singlet oxygen.

Recombinant adeno-associated virus mediates a high level of gene transfer but less efficient integration in the K562 human hematopoietic cell line.

PubMed Central

Malik, P; McQuiston, S A; Yu, X J; Pepper, K A; Krall, W J; Podsakoff, G M; Kurtzman, G J; Kohn, D B

1997-01-01

We tested the ability of a recombinant adeno-associated virus (rAAV) vector to express and integrate exogenous DNA into human hematopoietic cells in the absence of selection. We developed an rAAV vector, AAV-tNGFR, carrying a truncated rat nerve growth factor receptor (tNGFR) cDNA as a cell surface reporter under the control of the Moloney murine leukemia virus (MoMuLV) long terminal repeat. An analogous MoMuLV-based retroviral vector (L-tNGFR) was used in parallel, and gene transfer and expression in human hematopoietic cells were assessed by flow cytometry and DNA analyses. Following gene transfer into K562 cells with AAV-tNGFR at a multiplicity of infection (MOI) of 13 infectious units (IU), 26 to 38% of cells expressed tNGFR on the surface early after transduction, but the proportion of tNGFR expressing cells steadily declined to 3.0 to 3.5% over 1 month of culture. At an MOI of 130 IU, nearly all cells expressed tNGFR immediately posttransduction, but the proportion of cells expressing tNGFR declined to 62% over 2 months of culture. The decline in the proportion of AAV-tNGFR-expressing cells was associated with ongoing losses of vector genomes. In contrast, K562 cells transduced with the retroviral vector L-tNGFR expressed tNGFR in a constant fraction. Integration analyses on clones showed that integration occurred at different sites. Integration frequencies were estimated at about 49% at an MOI of 130 and 2% at an MOI of 1.3. Transduction of primary human CD34+ progenitor cells by AAV-tNGFR was less efficient than with K562 cells and showed a declining percentage of cells expressing tNGFR over 2 weeks of culture. Thus, purified rAAV caused very high gene transfer and expression in human hematopoietic cells early after transduction, which steadily declined during cell passage in the absence of selection. Although the efficiency of integration was low, overall integration was markedly improved at a high MOI. While prolonged episomal persistence may be adequate

Recombinant adeno-associated virus mediates a high level of gene transfer but less efficient integration in the K562 human hematopoietic cell line.

PubMed

Malik, P; McQuiston, S A; Yu, X J; Pepper, K A; Krall, W J; Podsakoff, G M; Kurtzman, G J; Kohn, D B

1997-03-01

We tested the ability of a recombinant adeno-associated virus (rAAV) vector to express and integrate exogenous DNA into human hematopoietic cells in the absence of selection. We developed an rAAV vector, AAV-tNGFR, carrying a truncated rat nerve growth factor receptor (tNGFR) cDNA as a cell surface reporter under the control of the Moloney murine leukemia virus (MoMuLV) long terminal repeat. An analogous MoMuLV-based retroviral vector (L-tNGFR) was used in parallel, and gene transfer and expression in human hematopoietic cells were assessed by flow cytometry and DNA analyses. Following gene transfer into K562 cells with AAV-tNGFR at a multiplicity of infection (MOI) of 13 infectious units (IU), 26 to 38% of cells expressed tNGFR on the surface early after transduction, but the proportion of tNGFR expressing cells steadily declined to 3.0 to 3.5% over 1 month of culture. At an MOI of 130 IU, nearly all cells expressed tNGFR immediately posttransduction, but the proportion of cells expressing tNGFR declined to 62% over 2 months of culture. The decline in the proportion of AAV-tNGFR-expressing cells was associated with ongoing losses of vector genomes. In contrast, K562 cells transduced with the retroviral vector L-tNGFR expressed tNGFR in a constant fraction. Integration analyses on clones showed that integration occurred at different sites. Integration frequencies were estimated at about 49% at an MOI of 130 and 2% at an MOI of 1.3. Transduction of primary human CD34+ progenitor cells by AAV-tNGFR was less efficient than with K562 cells and showed a declining percentage of cells expressing tNGFR over 2 weeks of culture. Thus, purified rAAV caused very high gene transfer and expression in human hematopoietic cells early after transduction, which steadily declined during cell passage in the absence of selection. Although the efficiency of integration was low, overall integration was markedly improved at a high MOI. While prolonged episomal persistence may be adequate

An Efficient Method for Electroporation of Small Interfering RNAs into ENCODE Project Tier 1 GM12878 and K562 Cell Lines.

PubMed

Muller, Ryan Y; Hammond, Ming C; Rio, Donald C; Lee, Yeon J

2015-12-01

The Encyclopedia of DNA Elements (ENCODE) Project aims to identify all functional sequence elements in the human genome sequence by use of high-throughput DNA/cDNA sequencing approaches. To aid the standardization, comparison, and integration of data sets produced from different technologies and platforms, the ENCODE Consortium selected several standard human cell lines to be used by the ENCODE Projects. The Tier 1 ENCODE cell lines include GM12878, K562, and H1 human embryonic stem cell lines. GM12878 is a lymphoblastoid cell line, transformed with the Epstein-Barr virus, that was selected by the International HapMap Project for whole genome and transcriptome sequencing by use of the Illumina platform. K562 is an immortalized myelogenous leukemia cell line. The GM12878 cell line is attractive for the ENCODE Projects, as it offers potential synergy with the International HapMap Project. Despite the vast amount of sequencing data available on the GM12878 cell line through the ENCODE Project, including transcriptome, chromatin immunoprecipitation-sequencing for histone marks, and transcription factors, no small interfering siRNA-mediated knockdown studies have been performed in the GM12878 cell line, as cationic lipid-mediated transfection methods are inefficient for lymphoid cell lines. Here, we present an efficient and reproducible method for transfection of a variety of siRNAs into the GM12878 and K562 cell lines, which subsequently results in targeted protein depletion.

Expression of transcription factors during sodium phenylacetate induced erythroid differentiation in K562 cells.

PubMed

Rath, A V; Schmahl, G E; Niemeyer, C M

1997-01-01

During 15 days of treatment of K562 cells with sodium phenylacetate, we observed an increase in the cellular hemoglobin concentration with a similar increase in the expression of gamma-globin mRNA. Morphological studies demonstrated characteristic features of erythroid differentiation and maturation. At the same time there was no change in the level of expression of the cell surface antigenes CD33, CD34, CD45, CD71 and glycophorin A. Likewise, the level of expression of the erythroid transcription factors GATA-1, GATA-2, NF-E2, SCL and RBTN2, all expressed in untreated K562 cells, did not increase during sodium phenylacetate induced erythroid differentiation. The expression of the nuclear factors Evi-1 and c-myb, known to inhibit erythroid differentiation, did not decrease. We conclude that sodium phenylacetate treatment of K562 cells increases gamma-globin mRNA and induces cell maturation as judged by morphology without affecting the expression of the erythroid transcription factors, some of which are known to be involved in the regulation of beta-like globin genes.

Synergistic effect of hydrogen peroxide on polyploidization during the megakaryocytic differentiation of K562 leukemia cells by PMA

PubMed Central

Ojima, Yoshihiro; Duncan, Mark Thompson; Nurhayati, Retno Wahyu; Taya, Masahito; Miller, William Martin

2013-01-01

The human myelogenous cell line, K562 has been extensively used as a model for the study of megakaryocytic (MK) differentiation, which could be achieved by exposure to phorbol 12-myristate 13-acetate (PMA). In this study, real-time PCR analysis revealed that the expression of catalase (cat) was significantly repressed during MK differentiation of K562 cells induced by PMA. In addition, PMA increased the intracellular reactive oxygen species (ROS) concentration, suggesting that ROS was a key factor for PMA-induced differentiation. PMA-differentiated K562 cells were exposed to hydrogen peroxide (H2O2) to clarify the function of ROS during MK differentiation. Interestingly, the percentage of high-ploidy (DNA content >4N) cells with H2O2 was 34.8±2.3% at day 9, and was 70% larger than that without H2O2 (21.5±0.8%). Further, H2O2 addition during the first 3 days of PMA-induced MK differentiation had the greatest effect on polyploidization. In an effort to elucidate the mechanisms of enhanced polyploidization by H2O2, the BrdU assay clearly indicated that H2O2 suppressed the division of 4N cells into 2N cells, followed by the increased polyploidization of K562 cells. These findings suggest that the enhancement in polyploidization mediated by H2O2 is due to synergistic inhibition of cytokinesis with PMA. Although H2O2 did not increase ploidy during the MK differentiation of primary cells, we clearly observed that cat expression was repressed in both immature and mature primary MK cells, and that treatment with the antioxidant N-acetylcysteine effectively blocked and/or delayed the polyploidization of immature MK cells. Together, these findings suggest that MK cells are more sensitive to ROS levels during earlier stages of maturation. PMID:23770036

Extracellular matrix stiffness causes systematic variations in proliferation and chemosensitivity in myeloid leukemias.

PubMed

Shin, Jae-Won; Mooney, David J

2016-10-25

Extracellular matrix stiffness influences biological functions of some tumors. However, it remains unclear how cancer subtypes with different oncogenic mutations respond to matrix stiffness. In addition, the relevance of matrix stiffness to in vivo tumor growth kinetics and drug efficacy remains elusive. Here, we designed 3D hydrogels with physical parameters relevant to hematopoietic tissues and adapted them to a quantitative high-throughput screening format to facilitate mechanistic investigations into the role of matrix stiffness on myeloid leukemias. Matrix stiffness regulates proliferation of some acute myeloid leukemia types, including MLL-AF9 + MOLM-14 cells, in a biphasic manner by autocrine regulation, whereas it decreases that of chronic myeloid leukemia BCR-ABL + K-562 cells. Although Arg-Gly-Asp (RGD) integrin ligand and matrix softening confer resistance to a number of drugs, cells become sensitive to drugs against protein kinase B (PKB or AKT) and rapidly accelerated fibrosarcoma (RAF) proteins regardless of matrix stiffness when MLL-AF9 and BCR-ABL are overexpressed in K-562 and MOLM-14 cells, respectively. By adapting the same hydrogels to a xenograft model of extramedullary leukemias, we confirm the pathological relevance of matrix stiffness in growth kinetics and drug sensitivity against standard chemotherapy in vivo. The results thus demonstrate the importance of incorporating 3D mechanical cues into screening for anticancer drugs.

Distinct Hypericum perforatum L. total extracts exert different antitumour activity on erythroleukemic K562 cells.

PubMed

Valletta, Elena; Rinaldi, Annamaria; Marini, Mario; Franzese, Ornella; Roscetti, Gianna

2018-05-22

Total flower extracts of Hypericum perforatum L. obtained with 3 different solvent systems were tested on tumour cell line cultures by comparing two groups of plants harvested in different times and places. The extracts, characterized according to the spectroscopic profile and the hypericin content, were tested on the growth and apoptotic death of K562 cells, a human erythroleukemic cell line. Growth and apoptosis were analysed by viable cell count, flow cytometry, and fluorescence microscopy at 6, 24, and 48 hr of culture following 1 hr exposure to the extracts under investigation. Here, we show that Hypericum extracts are able to reduce the growth of K562 cells and induce different degrees and kinetics of apoptosis according to the group of plants of origin. Also, we highlighted interesting differences in terms of efficacy among the extracts, with some samples losing their effectiveness along the culture time and others able to maintain or even increase their efficacy. Furthermore, the data herein obtained confirm the role of non hypericin compounds that are present in different proportions in the two plant groups and in the extracts analysed. Copyright © 2018 John Wiley & Sons, Ltd.

Reversal effect of a macrocyclic bisbibenzyl plagiochin E on multidrug resistance in adriamycin-resistant K562/A02 cells.

PubMed

Shi, Yan-Qiu; Qu, Xian-Jun; Liao, Yong-Xiang; Xie, Chun-Feng; Cheng, Yan-Na; Li, Song; Lou, Hong-Xiang

2008-04-14

Plagiochin E is a new macrocyclic bisbibenzyl compound isolated from Marchantia polymorpha. In the previous studies, we reported that when combined with fluconazole, plagiochin E had synergetic effects against the resistant strain of Candida albicans. Herein, we examined the reversal effect of plagiochin E on multidrug resistance in adriamycin-induced resistant K562/A02 cells and the parental K562 cells. Its cytotoxicity and reversal effects on multidrug resistance were assessed by MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl-tetrazolium bromide) assay. Apoptosis percentage of cells was obtained from Annexin V/fluorescein isothiocyanate (FITC) and propridium iodide (PI) double-staining. The effects of plagiochin E on P-glycoprotein activity were evaluated by measuring rhodamine 123 (Rh123)-associated mean fluorescence intensity and P-glycoprotein expression on the basis of the flow cytometric technology, respectively. The results showed that plagiochin E ranging from 2 to 12 mug/ml had little cytotoxicity against K562/A02 cells. When combined with adriamycin, it significantly promoted the sensitivity of K562/A02 cells toward adriamycin through increasing intracellular accumulation of adriamycin in a dose-dependent manner. Further study demonstrated that the inhibitory effect of plagiochin E on P-glycoprotein activity was the major cause of increased stagnation of adriamycin inside K562/A02 cells, indicating that plagiochin E, as a new class of mutidrug resistance inhibitor, may effectively reverse the multidrug resistance in K562/A02 cells via inhibiting expression and drug-transport function of P-glycoprotein.

Chronic myeloid leukemia progenitor cells require autophagy when leaving hypoxia-induced quiescence

PubMed Central

Ianniciello, Angela; Dumas, Pierre-Yves; Drullion, Claire; Guitart, Amélie; Villacreces, Arnaud; Peytour, Yan; Chevaleyre, Jean; Brunet de la Grange, Philippe; Vigon, Isabelle; Desplat, Vanessa; Priault, Muriel; Sbarba, Persio Dello; Ivanovic, Zoran; Mahon, François-Xavier; Pasquet, Jean-Max

2017-01-01

Albeit tyrosine kinase inhibitors anti-Abl used in Chronic Myeloid Leukemia (CML) block the deregulated activity of the Bcr-Abl tyrosine kinase and induce remission in 90% of patients, they do not eradicate immature hematopoietic compartments of leukemic stem cells. To elucidate if autophagy is important for stem cell survival and/or proliferation, we used culture in low oxygen concentration (0.1% O2 for 7 days) followed back by non-restricted O2 supply (normoxic culture) to mimic stem cell proliferation and commitment. Knockdown of Atg7 expression, a key player in autophagy, in K562 cell line inhibited autophagy compared to control cells. Upon 7 days at 0.1% O2 both K562 and K562 shATG7 cells stopped to proliferate and a similar amount of viable cells remained. Back to non-restricted O2 supply K562 cells proliferate whereas K562 shATG7 cells exhibited strong apoptosis. Using immunomagnetic sorted normal and CML CD34+ cells, we inhibited the autophagic process by lentiviral infection expressing shATG7 or using a Vps34 inhibitor. Both, normal and CML CD34+ cells either competent or deficient for autophagy stopped to proliferate in hypoxia. Surprisingly, while normal CD34+ cells proliferate back to non restricted O2 supply, the CML CD34+ cells deficient for autophagy failed to proliferate. All together, these results suggest that autophagy is required for CML CD34+ commitment while it is dispensable for normal CD34 cells. PMID:29228587

Synergistic effect of hydrogen peroxide on polyploidization during the megakaryocytic differentiation of K562 leukemia cells by PMA.

PubMed

Ojima, Yoshihiro; Duncan, Mark Thompson; Nurhayati, Retno Wahyu; Taya, Masahito; Miller, William Martin

2013-08-15

The human myelogenous cell line, K562 has been extensively used as a model for the study of megakaryocytic (MK) differentiation, which could be achieved by exposure to phorbol 12-myristate 13-acetate (PMA). In this study, real-time PCR analysis revealed that the expression of catalase (cat) was significantly repressed during MK differentiation of K562 cells induced by PMA. In addition, PMA increased the intracellular reactive oxygen species (ROS) concentration, suggesting that ROS was a key factor for PMA-induced differentiation. PMA-differentiated K562 cells were exposed to hydrogen peroxide (H2O2) to clarify the function of ROS during MK differentiation. Interestingly, the percentage of high-ploidy (DNA content >4N) cells with H2O2 was 34.8±2.3% at day 9, and was 70% larger than that without H2O2 (21.5±0.8%). Further, H2O2 addition during the first 3 days of PMA-induced MK differentiation had the greatest effect on polyploidization. In an effort to elucidate the mechanisms of enhanced polyploidization by H2O2, the BrdU assay clearly indicated that H2O2 suppressed the division of 4N cells into 2N cells, followed by the increased polyploidization of K562 cells. These findings suggest that the enhancement in polyploidization mediated by H2O2 is due to synergistic inhibition of cytokinesis with PMA. Although H2O2 did not increase ploidy during the MK differentiation of primary cells, we clearly observed that cat expression was repressed in both immature and mature primary MK cells, and that treatment with the antioxidant N-acetylcysteine effectively blocked and/or delayed the polyploidization of immature MK cells. Together, these findings suggest that MK cells are more sensitive to ROS levels during earlier stages of maturation. Copyright © 2013 Elsevier Inc. All rights reserved.

Genetically re-engineered K562 cells significantly expand and functionally activate cord blood natural killer cells: Potential for adoptive cellular immunotherapy.

PubMed

Ayello, Janet; Hochberg, Jessica; Flower, Allyson; Chu, Yaya; Baxi, Laxmi V; Quish, William; van de Ven, Carmella; Cairo, Mitchell S

2017-02-01

Natural killer (NK) cells play a significant role in reducing relapse in patients with hematological malignancies after allogeneic stem cell transplantation, but NK cell number and naturally occurring inhibitory signals limit their capability. Interleukin-15 (IL-15) and 4-1BBL are important modulators of NK expansion and functional activation. To overcome these limitations, cord blood mononuclear cells (CB MNCs) were ex vivo expanded for 7 days with genetically modified K562-mbIL15-41BBL (MODK562) or wild-type K562 (WTK562). NK cell expansion; expression of lysosome-associated membrane protein-1 (LAMP-1), granzyme B, and perforin; and in vitro and in vivo cytotoxicity against B-cell non-Hodgkin lymphoma (B-NHL) were evaluated. In vivo tumor growth in B-NHL-xenografted nonobese diabetic severe combined immune deficient (NOD-scid) gamma (NSG) mice was monitored by tumor volume, cell number, and survival. CB MNCs cultured with MODK562 compared with WTK562 demonstrated significantly increased NK expansion (thirty-fivefold, p < 0.05); LAMP-1 (p < 0.05), granzyme B, and perforin expression (p < 0.001); and in vitro cytotoxicity against B-NHL (p < 0.01). Xenografted mice treated with MODK562 CB experienced significantly decreased B-NHL tumor volume (p = 0.0086) and B-NHL cell numbers (p < 0.01) at 5 weeks and significantly increased survival (p < 0.001) at 10 weeks compared with WTK562. In summary, MODK562 significantly enhanced CB NK expansion and cytotoxicity, enhanced survival in a human Burkitt's lymphoma xenograft NSG model, and could be used in the future as adoptive cellular immunotherapy after umbilical CB transplantation. Future directions include expanding anti-CD20 chimeric receptor-modified CB NK cells to enhance B-NHL targeting in vitro and in vivo. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

Cytotoxic and apoptotic effects of different extracts of Artemisia biennis Willd. on K562 and HL-60 cell lines

PubMed Central

Tayarani-Najaran, Zahra; Makki, Farideh-Sadat; Alamolhodaei, Nafiseh-Sadat; Mojarrab, Mahdi; Emami, Seyed Ahmad

2017-01-01

Objective(s): Artemisia is a genus of herbs and small shrubs forms an important part of natural vegetation in Iran. It has been reported that several Artemisia species possess anti-proliferative effects. Considering the value of this genus in anti-cancer researches we have chosen Artemisia biennis for cytotoxic and mechanistic studies. Materials and Methods: In this study we have investigated the cytotoxic and apoptotic effects of petroleum ether, dichloromethane, ethyl acetate, ethanol, and ethanol: water (1:1 v/v) extracts of A. biennis Willd. on two cancer human cell lines (K562 and HL-60) and J774 as normal cells. Results: CH2Cl2 extract was found to have the highest anti-proliferative effect on cancer cells. IC50 values obtained in AlamarBlue® assay for CH2Cl2 extract were 64.86 and 54.31 µg/ml on K562 and HL-60 cells respectively. In flow cytometry histogram of the cells treated with CH2Cl2 extract, sub-G1 peak was induced. DNA fragmentation, increased in the level of Bax and cleavage of PARP protein all showed the induction of apoptosis with CH2Cl2 extract after 48 hr contact with cells. Conclusion: The results can corroborate the cytotoxic and apoptotic effects of the CH2Cl2 extract of A. biennis on the K562 and HL-60 cancer cell lines. PMID:28293393

IBTK Differently Modulates Gene Expression and RNA Splicing in HeLa and K562 Cells.

PubMed

Fiume, Giuseppe; Scialdone, Annarita; Rizzo, Francesca; De Filippo, Maria Rosaria; Laudanna, Carmelo; Albano, Francesco; Golino, Gaetanina; Vecchio, Eleonora; Pontoriero, Marilena; Mimmi, Selena; Ceglia, Simona; Pisano, Antonio; Iaccino, Enrico; Palmieri, Camillo; Paduano, Sergio; Viglietto, Giuseppe; Weisz, Alessandro; Scala, Giuseppe; Quinto, Ileana

2016-11-07

The IBTK gene encodes the major protein isoform IBTKα that was recently characterized as substrate receptor of Cul3-dependent E3 ligase, regulating ubiquitination coupled to proteasomal degradation of Pdcd4, an inhibitor of translation. Due to the presence of Ankyrin-BTB-RCC1 domains that mediate several protein-protein interactions, IBTKα could exert expanded regulatory roles, including interaction with transcription regulators. To verify the effects of IBTKα on gene expression, we analyzed HeLa and K562 cell transcriptomes by RNA-Sequencing before and after IBTK knock-down by shRNA transduction. In HeLa cells, 1285 (2.03%) of 63,128 mapped transcripts were differentially expressed in IBTK -shRNA-transduced cells, as compared to cells treated with control-shRNA, with 587 upregulated (45.7%) and 698 downregulated (54.3%) RNAs. In K562 cells, 1959 (3.1%) of 63128 mapped RNAs were differentially expressed in IBTK -shRNA-transduced cells, including 1053 upregulated (53.7%) and 906 downregulated (46.3%). Only 137 transcripts (0.22%) were commonly deregulated by IBTK silencing in both HeLa and K562 cells, indicating that most IBTKα effects on gene expression are cell type-specific. Based on gene ontology classification, the genes responsive to IBTK are involved in different biological processes, including in particular chromatin and nucleosomal organization, gene expression regulation, and cellular traffic and migration. In addition, IBTK RNA interference affected RNA maturation in both cell lines, as shown by the evidence of alternative 3'- and 5'-splicing, mutually exclusive exons, retained introns, and skipped exons. Altogether, these results indicate that IBTK differently modulates gene expression and RNA splicing in HeLa and K562 cells, demonstrating a novel biological role of this protein.

IBTK Differently Modulates Gene Expression and RNA Splicing in HeLa and K562 Cells

PubMed Central

Fiume, Giuseppe; Scialdone, Annarita; Rizzo, Francesca; De Filippo, Maria Rosaria; Laudanna, Carmelo; Albano, Francesco; Golino, Gaetanina; Vecchio, Eleonora; Pontoriero, Marilena; Mimmi, Selena; Ceglia, Simona; Pisano, Antonio; Iaccino, Enrico; Palmieri, Camillo; Paduano, Sergio; Viglietto, Giuseppe; Weisz, Alessandro; Scala, Giuseppe; Quinto, Ileana

2016-01-01

The IBTK gene encodes the major protein isoform IBTKα that was recently characterized as substrate receptor of Cul3-dependent E3 ligase, regulating ubiquitination coupled to proteasomal degradation of Pdcd4, an inhibitor of translation. Due to the presence of Ankyrin-BTB-RCC1 domains that mediate several protein-protein interactions, IBTKα could exert expanded regulatory roles, including interaction with transcription regulators. To verify the effects of IBTKα on gene expression, we analyzed HeLa and K562 cell transcriptomes by RNA-Sequencing before and after IBTK knock-down by shRNA transduction. In HeLa cells, 1285 (2.03%) of 63,128 mapped transcripts were differentially expressed in IBTK-shRNA-transduced cells, as compared to cells treated with control-shRNA, with 587 upregulated (45.7%) and 698 downregulated (54.3%) RNAs. In K562 cells, 1959 (3.1%) of 63128 mapped RNAs were differentially expressed in IBTK-shRNA-transduced cells, including 1053 upregulated (53.7%) and 906 downregulated (46.3%). Only 137 transcripts (0.22%) were commonly deregulated by IBTK silencing in both HeLa and K562 cells, indicating that most IBTKα effects on gene expression are cell type-specific. Based on gene ontology classification, the genes responsive to IBTK are involved in different biological processes, including in particular chromatin and nucleosomal organization, gene expression regulation, and cellular traffic and migration. In addition, IBTK RNA interference affected RNA maturation in both cell lines, as shown by the evidence of alternative 3′- and 5′-splicing, mutually exclusive exons, retained introns, and skipped exons. Altogether, these results indicate that IBTK differently modulates gene expression and RNA splicing in HeLa and K562 cells, demonstrating a novel biological role of this protein. PMID:27827994

Undifferentiated HL-60 cells internalize an antitumor alkyl ether phospholipid more rapidly than resistant K562 cells.

PubMed

Tsutsumi, T; Tokumura, A; Kitazawa, S

1998-02-05

In this study, we confirmed a previous finding that 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (methyl-PAF) expresses higher antineoplastic activity against the promyelocytic leukemia cell line HL-60, than against the erythroleukemic cell line K562, and intended to clarify the reason for this. Using an albumin back-exchange method, we measured the rates of binding and internalization of [3H]methyl-PAF by HL-60 and K562 cells. We found that methyl-PAF associated very rapidly and to similar extents with the two types of cells at low concentrations of extracellular bovine serum albumin, but that when bound to the cell surface, it was internalized into HL-60 cells faster than into K562 cells. The internalization of methyl-PAF by HL-60 cells was concentration-independent, intracellular ATP-independent and susceptible to thiol group-modifying reagents and cytochalasin B. Thus the inward transbilayer movement of methyl-PAF seems to occur by cytochalasin B-sensitive protein-mediated mechanism based on passive diffusion not requiring energy, in which SH-groups of protein play a critical role. We also found that the internalization of 1-hexadecanoyl-2-(4,4-difluoro-5,7- dimethyl-4-bora-3a, 4a-diaza-s-indacene-3-pentanoyl)-sn-glycero-3-phosphocholine (Bodipy-C5-PC), whose structure resembles that of methyl-PAF, into HL-60 cells was faster than that into K562 cells. Using a combination of an albumin back-exchange method and observation by confocal laser scanning microscopy, we next examined the intracellular distribution of this fluorescent phospholipid probe after its internalization. Intracellular membranes, especially those peripheral to nuclei, were fluorescence-labeled in both HL-60 and K562 cells, but fluorescence of the nuclear membranes was weak, suggesting that this probe seems mainly to accumulate in intracellular granules, and may interact directly with several key enzymes for phospholipid metabolism, leading to cell injury. Because the difference between

Rotenone isolated from Pachyrhizus erosus displays cytotoxicity and genotoxicity in K562 cells.

PubMed

Estrella-Parra, Edgar A; Gomez-Verjan, Juan C; González-Sánchez, Ignacio; Vázquez-Martínez, Edgar Ricardo; Vergara-Castañeda, Edgar; Cerbón, Marco A; Alavez-Solano, Dagoberto; Reyes-Chilpa, Ricardo

2014-01-01

Pachyrhizus erosus (Fabaceae) is a herb commonly known as 'yam bean', which has been cultivated in México since pre-Columbian times for its edible tubers. The seeds are also known for their acaricidal and insecticidal properties due to rotenone and other isoflavonoid contents. Rotenone has exhibited cytotoxic activity against several human tumour cell lines; however, its mechanism of action is still not fully understood. In this study, we determined the cytotoxicity of rotenone isolated from P. erosus seeds on K562 human leukaemia cells. Rotenone exhibited significant cytotoxic activity (IC50 = 13.05 μM), as determined by the MTT assay. Three other isolated isoflavonoids were not cytotoxic. Rotenone genotoxicity was detected using the comet assay. Rotenone induced cell death, and caspase-3 activation as indicated by TUNEL assay, and immunocytofluorescence. Plasmid nicking assay indicated that rotenone does not interact directly with DNA.

c-myb stimulates cell growth by regulation of insulin-like growth factor (IGF) and IGF-binding protein-3 in K562 leukemia cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Min-Sun; Kim, Sun-Young; Arunachalam, Sankarganesh

2009-07-17

c-myb plays an important role in the regulation of cell growth and differentiation, and is highly expressed in immature hematopoietic cells. The human chronic myelogenous leukemia cell K562, highly expresses IGF-I, IGF-II, IGF-IR, and IGF-induced cellular proliferation is mediated by IGF-IR. To characterize the impact of c-myb on the IGF-IGFBP-3 axis in leukemia cells, we overexpressed c-myb using an adenovirus gene transfer system in K562 cells. The overexpression of c-myb induced cell proliferation, compared to control, and c-myb induced cell growth was inhibited by anti-IGF-IR antibodies. c-myb overexpression resulted in a significant increase in the expression of IGF-I, IGF-II, andmore » IGF-IR, and a decrease in IGFBP-3 expression. By contrast, disruption of c-myb function by DN-myb overexpression resulted in significant reduction of IGF-I, IGF-II, IGF-IR, and elevation of IGFBP-3 expression. In addition, exogenous IGFBP-3 inhibited the proliferation of K562 cells, and c-myb induced cell growth was blocked by IGFBP-3 overexpression in a dose-dependent manner. The growth-promoting effects of c-myb were mediated through two major intracellular signaling pathways, Akt and Erk. Activation of Akt and Erk by c-myb was completely blocked by IGF-IR and IGFBP-3 antibodies. These findings suggest that c-myb stimulates cell growth, in part, by regulating expression of the components of IGF-IGFBP axis in K562 cells. In addition, disruption of c-myb function by DN-myb may provide a useful strategy for treatment of leukemia.« less

Glycometabolic adaptation mediates the insensitivity of drug-resistant K562/ADM leukaemia cells to adriamycin via the AKT-mTOR/c-Myc signalling pathway.

PubMed

Zhang, Xueyan; Ai, Ziying; Chen, Jing; Yi, Juan; Liu, Zhuan; Zhao, Huaishun; Wei, Hulai

2017-04-01

In human leukaemia, resistance to chemotherapy leads to treatment ineffectiveness or failure. Previous studies have indicated that cancers with increased levels of aerobic glycolysis are insensitive to numerous forms of chemotherapy and respond poorly to radiotherapy. Whether glycolysis serves a key role in drug resistance of leukaemia cells remains unclear. The present study systematically investigated aerobic glycolytic alterations and regulation in K562/adriamycin (ADM) multidrug‑resistant (MDR) and ADM‑sensitive K562 leukaemia cells in normoxia, and the association between drug resistance and improper glycometabolism. The cell proliferating activity was assessed with an MTT colorimetric assay, glycolysis, including glucose consumption, lactate export and key‑enzyme activity was determined by corresponding commercial testing kits. The expression levels of hexokinase‑II (HK‑II), lactate dehydrogenase A (LDHA), glucose transporter‑4 (GLUT‑4), AKT, p‑AKT473/308, mammalian target of rapamycin (mTOR), p‑mTOR, c‑Myc and hypoxia‑inducible factor‑1α (HIF‑1α) were analyzed by western blot or reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). K562/ADM cells exhibited increased glucose consumption and lactate accumulation, increased lactate dehydrogenase, hexokinase and pyruvate kinase activities, and reduced phosphofructokinase activity. In addition, K562/ADM cells expressed significantly more HK‑II and GLUT‑4. Notably, inhibition of glycolysis effectively killed sensitive and resistant leukaemia cells and potently restored the sensitivity of MDR cells to the anticancer agent ADM. The AKT serine/threonine kinase (AKT)/mechanistic target of rapamycin (mTOR) signalling pathway, a crucial regulator of glycometabolic homeostasis, mediated over‑activation and upregulation of c‑Myc expression levels in K562/ADM cells, which directly stimulated glucose consumption and enhanced glycolysis. In conclusion, the present

Differentiation of K562 cells under ELF-EMF applied at different time courses.

PubMed

Ayşe, Inhan-Garip; Zafer, Akan; Sule, Oncul; Işil, Işal-Turgut; Kalkan, Tunaya

2010-08-01

The time-course of ELF-EMF application to biological systems is thought to be an important parameter determining the physiological outcome. This study investigated the effect of ELF-EMF on the differentiation of K562 cells at different time courses. ELF-EMF (50 Hz, 5 mT, 1 h) was applied at two different time-courses; first at the onset of hemin induction for 1 h, and second, daily 1 h for four days. While single exposure to ELF-EMF resulted in a decrease in differentiation, ELF-EMF applied everyday for 1 h caused an increase in differentiation. The effect of co-stressors, magnesium, and heat-shock was also determined and similar results were obtained. ELF-EMF increased ROS levels in K562 cells not treated with hemin, however did not change ROS levels of hemin treated cells indicating that ROS was not the cause. Overall, these results imply that the time-course of application is an important parameter determining the physiological response of cells to ELF-EMF.

Cytotoxic and Apoptotic Effects of Different Extracts of Artemisia turanica Krasch. on K562 and HL-60 Cell Lines

PubMed Central

Tayarani-Najaran, Zahra; Sareban, Mahla; Gholami, Atefeh; Emami, Seyed Ahmad; Mojarrab, Mahdi

2013-01-01

Artemisia is an important genus of Iranian flora. Cytotoxic activities for some species of the genus have already been reported. In this study, we have investigated the cytotoxic effects of n-hexane, CH2Cl2, EtOAc, EtOH, and EtOH/H2O (1 : 1) extracts of A. turanica Krasch. on two human leukemic cancer cell lines (K562 and HL-60) and J774 as normal cells using alamarBlue (resazurin) assay. PI staining of the fragmented DNA and western blot analysis were used to evaluate the possible apoptotic effect of the extract. The CH2Cl2 extract of A. turanica showed the most antiproliferative effect on cancer cells among all tested extracts with IC50 values of 69 and 104 μg/mL on K562 and HL-60 cells, respectively, whereas the normal cells were not affected significantly by this extract. Sub-G1 peak in the flow cytometry histogram of the cells treated with CH2Cl2 extract of A. turanica and cleavage of PARP protein confirmed the induction of apoptosis with CH2Cl2 extract. Taken together, the findings of the present work suggest the anticancer potential of CH2Cl2 extract of A. turanica on human leukemic cancer cell lines. PMID:24288497

Apoptosis of leukemia K562 and Molt-4 cells induced by emamectin benzoate involving mitochondrial membrane potential loss and intracellular Ca2+ modulation.

PubMed

Yun, Xinming; Rao, Wenbing; Xiao, Ciying; Huang, Qingchun

2017-06-01

Leukemia threatens millions of people's health and lives, and the pesticide-induced leukemia has been increasingly concerned because of the etiologic exposure. In this paper, cytotoxic effect of emamectin benzoate (EMB), an excellent natural-product insecticide, was evaluated through monitoring cell viability, cell apoptosis, mitochondrial membrane potential and intracellular Ca 2+ concentration ([Ca 2+ ] i ) in leukemia K562 and Molt-4 cells. Following the exposure to EMB, cell viability was decreased and positive apoptosis of K562 and Molt-4 cells was increased in a concentration- and time- dependent fashion. In the treatment of 10μM EMB, apoptotic cells accounted for 93.0% to K562 cells and 98.9% to Molt-4 cells based on the control, meanwhile, 63.47% of K562 cells and 81.15% of Molt-4 cells exhibited late apoptotic and necrotic features with damaged cytoplasmic membrane. 48h exposure to 10μM EMB increased significantly the great number of cells with mitochondrial membrane potential (MMP) loss, and the elevation of [Ca 2+ ] i level was peaked and persisted within 70s in K562 cells whilst 50s in Molt-4 cells. Moreover, a stronger cytotoxicity of EMB was further observed than that of imatinib. The results authenticate the efficacious effect of EMB as a potential anti-leukemia agent and an inconsistency with regard to insecticide-induced leukemia. Copyright © 2017 Elsevier B.V. All rights reserved.

Bcr-Abl-independent mechanism of resistance to imatinib in K562 cells: Induction of cyclooxygenase-2 (COX-2) by histone deacetylases (HDACs).

PubMed

Kalle, Arunasree M; Sachchidanand, Sachchidanand; Pallu, Reddanna

2010-09-01

Our previous studies have shown that overexpression of MDR1 and cyclooygenase-2 (COX-2) resulted in resistance development to imatinib in chronic myelogenous leukemia (CML) K562 (IR-K562) cells. In the present study, the regulatory mechanism of MDR1 induction by COX-2 was investigated. A gradual overexpression of MDR1 and COX-2 during the process of development was observed. Furthermore, down regulation of MDR1 upon COX-2 knockdown by siRNA showed a decrease in the PKC levels and activation of PKC by addition of PGE(2) to K562 cells, suggesting a role for PKC in the COX-2 mediated induction of MDR1. The present study demonstrates COX-2 induction by HDACs and MDR1 induction by COX-2 via PGE(2)-cAMP-PKC-mediated pathway. Copyright 2010 Elsevier Ltd. All rights reserved.

Analysis of the Effects of δ-Tocopherol on RAW264.7 and K562 Cells Based on 1H NMR Metabonomics.

PubMed

Lu, Yang; Li, Hui; Geng, Yue

2018-01-31

δ-Tocopherol (δ-TOH) is a form of vitamin E with higher bioactivity. In this study, we studied the bioactivity of δ-TOH using the IC 50 of δ-TOH on RAW264.7 (80 μM) and K562 (110 μM) cells. We compared the differential metabolites from the cell lines with and without δ-TOH treatment by 1 H NMR metabonomics analysis. It was found that δ-TOH affected the protein biosynthesis, betaine metabolism, and urea cycle in various ways in both cell lines. Metabolic levels of the cell lines were changed after treatment with δ-TOH as differential metabolites were produced. The betaine level in RAW264.7 cells was reduced significantly, while the l-lactic acid level in K562 cells was significantly enhanced. The metabolic changes might contribute to the switch of the respiration pattern from aerobic respiration to anaerobic respiration in K562 cells. These results are helpful in further understanding the subtoxicity of δ-TOH.

Differential chemosensitization of P-glycoprotein overexpressing K562/Adr cells by withaferin A and Siamois polyphenols

PubMed Central

2010-01-01

Background Multidrug resistance (MDR) is a major obstacle in cancer treatment and is often the result of overexpression of the drug efflux protein, P-glycoprotein (P-gp), as a consequence of hyperactivation of NFκB, AP1 and Nrf2 transcription factors. In addition to effluxing chemotherapeutic drugs, P-gp also plays a specific role in blocking caspase-dependent apoptotic pathways. One feature that cytotoxic treatments of cancer have in common is activation of the transcription factor NFκB, which regulates inflammation, cell survival and P-gp expression and suppresses the apoptotic potential of chemotherapeutic agents. As such, NFκB inhibitors may promote apoptosis in cancer cells and could be used to overcome resistance to chemotherapeutic agents. Results Although the natural withanolide withaferin A and polyphenol quercetin, show comparable inhibition of NFκB target genes (involved in inflammation, angiogenesis, cell cycle, metastasis, anti-apoptosis and multidrug resistance) in doxorubicin-sensitive K562 and -resistant K562/Adr cells, only withaferin A can overcome attenuated caspase activation and apoptosis in K562/Adr cells, whereas quercetin-dependent caspase activation and apoptosis is delayed only. Interestingly, although withaferin A and quercetin treatments both decrease intracellular protein levels of Bcl2, Bim and P-Bad, only withaferin A decreases protein levels of cytoskeletal tubulin, concomitantly with potent PARP cleavage, caspase 3 activation and apoptosis, at least in part via a direct thiol oxidation mechanism. Conclusions This demonstrates that different classes of natural NFκB inhibitors can show different chemosensitizing effects in P-gp overexpressing cancer cells with impaired caspase activation and attenuated apoptosis. PMID:20438634

Regulation of HtrA2 on WT1 gene expression under imatinib stimulation and its effects on the cell biology of K562 cells.

PubMed

Zhang, Lixia; Li, Yan; Li, Xiaoyan; Zhang, Qing; Qiu, Shaowei; Zhang, Qi; Wang, Min; Xing, Haiyan; Rao, Qing; Tian, Zheng; Tang, Kejing; Wang, Jianxiang; Mi, Yingchang

2017-09-01

The aim of the present study was to investigate the regulation of Wilms Tumor 1 (WT1) by serine protease high-temperature requirement protein A2 (HtrA2), a member of the Htr family, in K562 cells. In addition, the study aimed to observe the effect of this regulation on cell biological functions and its associated mechanisms. Expression of WT1 and HtrA2 mRNA, and proteins following imatinib and the HtrA2 inhibitor 5-[5-(2-nitrophenyl) furfuryl iodine]-1, 3-diphenyl-2-thiobarbituric acid (UCF-101) treatment was detected with reverse transcription-quantitative polymerase chain reaction and western blot analysis. Subsequent to treatment with drugs and UCF-101, the proliferative function of K562 cells was detected using MTT assays, and the rate of apoptosis was detected using Annexin V with propidium iodide flow cytometry in K562 cells. The protein levels in the signaling pathway were analyzed using western blotting following treatment with imatinib and UCF-101. In K562 cells, imatinib treatment activated HtrA2 gene at a transcription level, while the WT1 gene was simultaneously downregulated. Following HtrA2 inhibitor (UCF-101) treatment, the downregulation of WT1 increased gradually. At the protein level, imatinib induced the increase in HtrA2 protein level and concomitantly downregulated WT1 protein level. Subsequent to HtrA2 inhibition by UCF-101, the WT1 protein level decreased temporarily, but eventually increased. Imatinib induced apoptosis in K562 cells, but this effect was attenuated by the HtrA2 inhibitor UCF-101, resulting in the upregulation of the WT1 protein level. However; UCF-101 did not markedly change the proliferation inhibition caused by imatinib. Imatinib activated the p38 mitogen activated protein kinase (p38 MAPK) signaling pathway in K562 cells, and UCF-101 affected the activation of imatinib in the p38 MAPK signaling pathway. Imatinib inhibited the extracellular signal-related kinase (ERK1/2) pathway markedly and persistently, but UCF-101

Jellyfish extract induces apoptotic cell death through the p38 pathway and cell cycle arrest in chronic myelogenous leukemia K562 cells

PubMed Central

Kwak, Choong-Hwan; Abekura, Fukushi; Park, Jun-Young; Park, Nam Gyu; Chang, Young-Chae; Lee, Young-Choon; Chung, Tae-Wook; Ha, Ki-Tae; Son, Jong-Keun

2017-01-01

Jellyfish species are widely distributed in the world’s oceans, and their population is rapidly increasing. Jellyfish extracts have several biological functions, such as cytotoxic, anti-microbial, and antioxidant activities in cells and organisms. However, the anti-cancer effect of Jellyfish extract has not yet been examined. We used chronic myelogenous leukemia K562 cells to evaluate the mechanisms of anti-cancer activity of hexane extracts from Nomura’s jellyfish in vitro. In this study, jellyfish are subjected to hexane extraction, and the extract is shown to have an anticancer effect on chronic myelogenous leukemia K562 cells. Interestingly, the present results show that jellyfish hexane extract (Jellyfish-HE) induces apoptosis in a dose- and time-dependent manner. To identify the mechanism(s) underlying Jellyfish-HE-induced apoptosis in K562 cells, we examined the effects of Jellyfish-HE on activation of caspase and mitogen-activated protein kinases (MAPKs), which are responsible for cell cycle progression. Induction of apoptosis by Jellyfish-HE occurred through the activation of caspases-3,-8 and -9 and phosphorylation of p38. Jellyfish-HE-induced apoptosis was blocked by a caspase inhibitor, Z-VAD. Moreover, during apoptosis in K562 cells, p38 MAPK was inhibited by pretreatment with SB203580, an inhibitor of p38. SB203580 blocked jellyfish-HE-induced apoptosis. Additionally, Jellyfish-HE markedly arrests the cell cycle in the G0/G1 phase. Therefore, taken together, the results imply that the anti-cancer activity of Jellyfish-HE may be mediated apoptosis by induction of caspases and activation of MAPK, especially phosphorylation of p38, and cell cycle arrest at the Go/G1 phase in K562 cells. PMID:28133573

A new disposable electrode for electrochemical study of leukemia K562 cells and anticancer drug sensitivity test.

PubMed

Yu, Chunmei; Zhu, Zhenkun; Wang, Li; Wang, Qiuhong; Bao, Ning; Gu, Haiying

2014-03-15

Developing cost-effective and simple analysis tools is of vital importance for practical applications in bioanalysis. In this work, a new disposable electrochemical cell sensor with low cost and simple fabrication was proposed to study the electrochemical behavior of leukemia K562 cells and the effect of anticancer drugs on cell viability. The analytical device was integrated by using ITO glass as the substrate of working electrodes and paper as the electrolytic cell. The cyclic voltammetry of the K562 cells at the disposable electrode exhibited an irreversible anodic peak and the peak current is proportional to the cell number. This anodic peak is attributed to the oxidation of guanine in cells involving two protons per transfer of two electrons. For the drug sensitivity tests, arsenic trioxide and cyclophosphamide were added to cell culture media. As a result, the electrochemical responses of the K562 cells decreased significantly. The cytotoxicity curves and results obtained corresponded well with the results of CCK-8 assays. In comparison to conventional methods, the proposed method is simple, rapid and inexpensive. More importantly, the developed sensor is supposed to be a single-use disposable device and electrodes were prepared "as new" for each experiment. We think that such disposable electrodes with these characteristics are suitable for experimental study with cancer cells or other types of pathogens for disease diagnosis, drug selection and on-site monitoring. © 2013 Elsevier B.V. All rights reserved.

Involvement of PKC and ROS in the cytotoxic mechanism of anti-leukemic decursin and its derivatives and their structure-activity relationship in human K562 erythroleukemia and U937 myeloleukemia cells.

PubMed

Kim, Hyeon Ho; Sik Bang, Sung; Seok Choi, Jin; Han, Hogyu; Kim, Ik-Hwan

2005-06-08

Protein kinase C (PKC) plays an important role in the proliferation and differentiation of various cell types including normal and leukemic hematopoietic cells. Recently, various PKC modulators were used as a chemotherapeutic agent of leukemia. Decursin (1), a pyranocoumarin from Angelica gigas, exhibits the cytotoxic effects on various human cancer cell lines and in vitro PKC activation. For the development of more effective anticancer agents with PKC modulation activity, 11 decursin derivatives 2-12 were chemically synthesized and evaluated for their ability to act as a tumor-suppressing PKC activator and as an antagonist to phorbol 12-myristate 13-acetate (PMA), a tumor-promoting PKC activator. In the presence of phosphatidylserine (PS), all of 12 compounds 1-12 activated PKC (mainly alpha, beta, and gamma isozymes) but only three compounds 1-3 activated PKC even in the absence of PS. Six compounds 1-6 containing the coumarin structure were cytotoxic to human K562 erythroleukemia and U937 myeloleukemia cells. A cytotoxic mechanism of decursin and its derivatives was investigated using TUR cells, a PKC betaII-deficient variant of U937 cells. Among six compounds 1-6 with cytotoxicity to K562 and U937 leukemia cells, only three compounds 1-3 were cytotoxic to TUR cells. Therefore, compounds 1-3 and 4-6 inhibit the proliferation of leukemia cells in a PKC betaII-independent and dependent manner, respectively, indicating that the side chain of compounds determines the dependency of their cytotoxicity on PKC betaII. To further elucidate the cytotoxic mechanism of compounds 1 and 2, levels of PKC isozymes and generation of reactive oxygen species (ROS) were investigated. Compounds 1-2 induced the down-regulation of PKC alpha and betaII in K562 cells and the production of ROS in U937 cells. Thus, PKC and ROS are probably important factors in the cytotoxic mechanism of compounds 1-2. From these results, the structure-activity relationship of decursin and its derivatives

Aberrant expression of CKLF-like MARVEL transmembrane member 5 (CMTM5) by promoter methylation in myeloid leukemia.

PubMed

Niu, Jihong; Li, Henan; Zhang, Yao; Li, Jinlan; Xie, Min; Li, Lingdi; Qin, Xiaoying; Qin, Yazhen; Guo, Xiaohuan; Jiang, Qian; Liu, Yanrong; Chen, Shanshan; Huang, Xiaojun; Han, Wenling; Ruan, Guorui

2011-06-01

CMTM5 has been shown to exhibit tumor suppressor activities, however, its role in leukemia is unclear. Herein we firstly reported the expression and function of CMTM5 in myeloid leukemia. CMTM5 was down-regulated, or undetectable, in leukemia cell lines and bone marrow cells from leukemia patients with promoter methylation. Ectopic expression of CMTM5-v1 strongly inhibited the proliferation of K562 and MEG-01 cells. In addition, significant negative correlations were observed between CMTM5 and three leukemia-specific fusion genes (AML1-ETO, PML-RARα and BCR/ABL1). CMTM5 expression was up-regulated in patients who had undergone treatment. Therefore, CMTM5 may be involved in the pathomechanism of myeloid leukemias. Copyright © 2010 Elsevier Ltd. All rights reserved.

Comparative Study of Different Nano-Formulations of Curcumin for Reversal of Doxorubicin Resistance in K562R Cells.

PubMed

Dash, Tapan K; Konkimalla, V Badireenath

2017-02-01

Curcumin is very well established as a chemo-therapeutic, chemo-preventive and chemo-sensitizing agent in diverse disease conditions. As the isolated pure form has poor solubility and pharmacokinetic problems, therefore it is encapsulated in to several nano-formulations to improve its bioavailability. Here in the current study, we aim to compare different nano-formulations of curcumin for their chemo-sensitizing activity in doxorubicin (DOX) resistant K562 cells. Four different curcumin formulations were prepared namely DMSO assisted curcumin nano-dispersion (CurD, 260 nm), liposomal curcumin (CurL, 165 nm), MPEG-PCL micellar curcumin (CurM, 18 nm) and cyclodextrin encapsulated curcumin (CurN, 37 nm). The formulations were subjected to particle characterizations (size, zeta potential, release studies), followed by biological assays such as cellular uptake, P-gp inhibitory activity and reversal of DOX resistance by co-treatment with DOX. Curcumin uptake in K562N and K562R cells was mildly reduced when treated with CurL and CurM, while for CurD and CurN the uptake remained equivalent. However, CurL retained P-gp inhibitory activity of curcumin and with a considerable chemo-sensitizing effect but CurM showed no P-gp inhibitory activity. CurN retained above biological activities, but requires a secondary carrier under in vivo conditions. From the results, CurM was found to be most suitable for solubilization of curcumin where as CurL can be considered as most suitable nano-formulation for reversal of DOX resistance.

Thiosemicarbazone p-Substituted Acetophenone Derivatives Promote the Loss of Mitochondrial Δψ, GSH Depletion, and Death in K562 Cells

PubMed Central

Pessoto, Felipe S.; Yokomizo, Cesar H.; Prieto, Tatiana; Fernandes, Cleverton S.; Silva, Alan P.; Kaiser, Carlos R.; Basso, Ernani A.; Nantes, Iseli L.

2015-01-01

A series of thiosemicarbazone (TSC) p-substituted acetophenone derivatives were synthesized and chemically characterized. The p-substituents appended to the phenyl group of the TSC structures were hydrogen, fluor, chlorine, methyl, and nitro, producing compounds named TSC-H, TSC-F, TSC-Cl, TSC-Me, and TSC-NO2, respectively. The TSC compounds were evaluated for their capacity to induce mitochondrial permeability, to deplete mitochondrial thiol content, and to promote cell death in the K562 cell lineage using flow cytometry and fluorescence microscopy. TSC-H, TSC-F, and TSC-Cl exhibited a bell-shaped dose-response curve for the induction of apoptosis in K562 cells due to the change from apoptosis to necrosis as the principal mechanism of cell death at the highest tested doses. TSC-Me and TSC-NO2 exhibited a typical dose-response profile, with a half maximal effective concentration of approximately 10 µM for cell death. Cell death was also evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, which revealed lower toxicity of these compounds for peripheral blood mononuclear cells than for K562 cells. The possible mechanisms leading to cell death are discussed based on the observed effects of the new TSC compounds on the cellular thiol content and on mitochondrial bioenergetics. PMID:26075034

Mechanistic Evaluation for Mixed-field Agglutination in the K562 Cell Study Model with Exon 3 Deletion of A1 Gene.

PubMed

Chen, Ding-Ping; Tseng, Ching-Ping; Lin, Chi-Jui; Wang, Wei-Ting; Sun, Chien-Feng

2015-01-01

In the case of blood type B3 with typical mixed-field agglutination of RBCs in the presence of anti-B or anti-AB antibody, a number of genetic alternations have been reported. It is well known that the IVS3+5G→A mutation in the B gene destroys the consensus of the splice donor site leading to exon 3 skipping during mRNA splicing. The lack of exon 3 likely causes a short stem region, producing an unstable B3 protein, and is concomitant with a decrease in B3 protein expression. Whether the phenomenon also appears in the type A blood group is of question. In this study, we evaluate whether exon 3 deletion in the blood type A gene also results in mixed-field phenotype. Site-directed mutagenesis was used to generate cDNA encoding A1 gene with exon 3 deletion. The cDNA was stably expressed in K562 cells. The expression of A antigen was compared with expression in parental K562 cells that did not express A antigen and in the stable K562 cell line expressing A(1) cDNA by flow cytometry analyses. The expression of A antigen in A1 stable cells and parental K562 cells was set as 100% and 0%, respectively. The mean relative percentage of A antigen expression for the cells of A1 with exon 3 deletion was 59.9% of A1 stable cells. Consistent with the observations of B3, which is B gene with exon 3 deletion, mixed field agglutination was observed for the cells expressing A1 with exon 3 deletion. Exon 3 deletion results in mixed field phenotype in both type A and B RBCs. However, the degree of antigen expression change for exon 3 deletion in A gene was less severe when compared with the deletion occurred in B gene. © 2015 by the Association of Clinical Scientists, Inc.

Inhibitory effects of physalin B and physalin F on various human leukemia cells in vitro.

PubMed

Chiang, H C; Jaw, S M; Chen, P M

1992-01-01

Physalins B and F were isolated and characterized from the ethanolic extract of the whole plant of Physalis angulata L. (Solanaceae). Both physalin B and physalin F inhibited the growth of several human leukemia cells: K562 (erythroleukemia), APM1840 (acute T lymphoid leukemia), HL-60 (acute promyelocytic leukemia), KG-1 (acute myeloid leukemia), CTV1 (acute monocytic leukemia) and B cell (acute B lymphoid leukemia). Physalin F showed a stronger activity against these leukemia cells than physalin B, especially against acute myeloid leukemia (KG-1) and acute B lymphoid leukemia (B cell). From the structural features, the active site seems to be the functional epoxy group for physalin F and the double bond for physalin B located at carbon 5 and 6; the former is much more active than the latter as regards anti-leukemic effects.

Potassium Channels Mediate Killing by Human Natural Killer Cells

NASA Astrophysics Data System (ADS)

Schlichter, Lyanne; Sidell, Neil; Hagiwara, Susumu

1986-01-01

Human natural killer (NK) cells in peripheral blood spontaneously recognize and kill a wide variety of target cells. It has been suggested that ion channels are involved in the killing process because there is a Ca-dependent stage and because killing by presensitized cytotoxic T lymphocytes, which in many respects resembles NK killing, is associated with changes in K and Na transport in the target cell. However, no direct evidence exists for ion channels in NK cells or in their target cells. Using the whole-cell variation of the patch-clamp technique, we found a voltage-dependent potassium (K+) current in NK cells. The K+ current was reduced in a dose-dependent manner by the K-channel blockers 4-aminopyridine and quinidine and by the traditional Ca-channel blockers verapamil and Cd2+. We tested the effects of ion-channel blockers on killing of two commonly used target cell lines: K562, which is derived from a human myeloid leukemia, and U937, which is derived from a human histiocytic leukemia. Killing of K562 target cells, determined in a standard 51Cr-release assay, was inhibited in a dose-dependent manner by verapamil, quinidine, Cd2+, and 4-aminopyridine at concentrations comparable to those that blocked the K+ current in NK cells. In K562 target cells only a voltage-dependent Na+ current was found and it was blocked by concentrations of tetrodotoxin that had no effect on killing. Killing of U937 target cells was also inhibited by the two ion-channel blockers tested, quinidine and verapamil. In this cell line only a small K+ current was found that was similar to the one in NK cells. We could not find any evidence of a Ca2+ current in target cells or in NK cells; therefore, our results cannot explain the Ca dependence of killing. Our findings show that there are K channels in NK cells and that these channels play a necessary role in the killing process. In contrast, the endogenous channel type in the target cell is probably not a factor in determining target cell

Anti-Tumor Activity of Eurycoma longifolia Root Extracts against K-562 Cell Line: In Vitro and In Vivo Study

PubMed Central

Majid, Amin Malik Shah Abdul; Kit-Lam, Chan; Abdullah, Wan Zaidah; Zaki, Abdelhamid; Jamal Din, Shah Kamal Khan; Yusoff, Narazah Mohd

2014-01-01

Eurycoma longifolia Jack has been widely used in traditional medicine for its antimalarial, aphrodisiac, anti-diabetic, antimicrobial and anti-pyretic activities. Its anticancer activity has also been recently reported on different solid tumors, however no anti-leukemic activity of this plant has been reported. Thus the present study assesses the in vitro and in vivo anti-proliferative and apoptotic potentials of E. longifolia on K-562 leukemic cell line. The K-562 cells (purchased from ATCC) were isolated from patients with chronic myelocytic leukemia (CML) were treated with the various fractions (TAF273, F3 and F4) of E. longifolia root methanolic extract at various concentrations and time intervals and the anti-proliferative activity assessed by MTS assay. Flow cytometry was used to assess the apoptosis and cell cycle arrest. Nude mice injected subcutaneously with 107 K-562 cells were used to study the anti-leukemic activity of TAF273 in vivo. TAF273, F3 and F4 showed various degrees of growth inhibition with IC50 values of 19, 55 and 62 µg/ml, respectively. TAF273 induced apoptosis in a dose and time dependent manner. TAF273 arrested cell cycle at G1and S phases. Intraperitoneal administration of TAF273 (50 mg/kg) resulted in a significant growth inhibition of subcutaneous tumor in TAF273-treated mice compared with the control mice (P = 0.024). TAF273 shows potent anti-proliferative activity in vitro and in vivo models of CML and therefore, justifies further efforts to define more clearly the potential benefits of using TAF273 as a novel therapeutic strategy for CML management. PMID:24409284

The c-myb proto-oncogene and microRNA-15a comprise an active autoregulatory feedback loop in human hematopoietic cells

PubMed Central

Zhao, Huiwu; Kalota, Anna; Jin, Shenghao

2009-01-01

The c-myb proto-oncogene encodes an obligate hematopoietic cell transcription factor important for lineage commitment, proliferation, and differentiation. Given its critical functions, c-Myb regulatory factors are of great interest but remain incompletely defined. Herein we show that c-Myb expression is subject to posttranscriptional regulation by microRNA (miRNA)–15a. Using a luciferase reporter assay, we found that miR-15a directly binds the 3′-UTR of c-myb mRNA. By transfecting K562 myeloid leukemia cells with a miR-15a mimic, functionality of binding was shown. The mimic decreased c-Myb expression, and blocked the cells in the G1 phase of cell cycle. Exogenous expression of c-myb mRNA lacking the 3′-UTR partially rescued the miR-15a induced cell-cycle block. Of interest, the miR-15a promoter contained several potential c-Myb protein binding sites. Occupancy of one canonical c-Myb binding site was demonstrated by chromatin immunoprecipitation analysis and shown to be required for miR-15a expression in K562 cells. Finally, in studies using normal human CD34+ cells, we showed that c-Myb and miR-15a expression were inversely correlated in cells undergoing erythroid differentiation, and that overexpression of miR-15a blocked both erythroid and myeloid colony formation in vitro. In aggregate, these findings suggest the presence of a c-Myb–miR-15a autoregulatory feedback loop of potential importance in human hematopoiesis. PMID:18818396

Silencing of BCR/ABL Chimeric Gene in Human Chronic Myelogenous Leukemia Cell Line K562 by siRNA-Nuclear Export Signal Peptide Conjugates.

PubMed

Shinkai, Yasuhiro; Kashihara, Shinichi; Minematsu, Go; Fujii, Hirofumi; Naemura, Madoka; Kotake, Yojiro; Morita, Yasutaka; Ohnuki, Koichiro; Fokina, Alesya A; Stetsenko, Dmitry A; Filichev, Vyacheslav V; Fujii, Masayuki

2017-06-01

Herein we described the synthesis of siRNA-NES (nuclear export signal) peptide conjugates by solid phase fragment coupling and the application of them to silencing of bcr/abl chimeric gene in human chronic myelogenous leukemia cell line K562. Two types of siRNA-NES conjugates were prepared, and both sense strands at 5' ends were covalently linked to a NES peptide derived from TFIIIA and HIV-1 REV, respectively. Significant enhancement of silencing efficiency was observed for both of them. siRNA-TFIIIA NES conjugate suppressed the expression of BCR/ABL gene to 8.3% at 200 nM and 11.6% at 50 nM, and siRNA-HIV-1REV NES conjugate suppressed to 4.0% at 200 nM and 6.3% at 50 nM, whereas native siRNA suppressed to 36.3% at 200 nM and 30.2% at 50 nM. We could also show complex of siRNA-NES conjugate and designed amphiphilic peptide peptideβ7 could be taken up into cells with no cytotoxicity and showed excellent silencing efficiency. We believe that the complex siRNA-NES conjugate and peptideβ7 is a promising candidate for in vivo use and therapeutic applications.

The t(3;5)(q25.1;q34) of myelodysplastic syndrome and acute myeloid leukemia produces a novel fusion gene, NPM-MLF1.

PubMed

Yoneda-Kato, N; Look, A T; Kirstein, M N; Valentine, M B; Raimondi, S C; Cohen, K J; Carroll, A J; Morris, S W

1996-01-18

A t(3;5)(q25.1;q34) chromosomal translocation associated with myelodysplastic syndrome and acute myeloid leukemia (AML) was found to rearrange part of the nucleophosmin (NPM) gene on chromosome 5 with sequences from a novel gene on chromosome 3. Chimeric transcripts expressed by these cells contain 5' NPM coding sequences fused in-frame to those of the new gene, which we named myelodysplasia/myeloid leukemia factor 1 (MLF1). RNA-based polymerase chain reaction analysis revealed identical NPM-MLF1 mRNA fusions in each of the three t(3;5)-positive cases of AML examined. The predicted MLF1 amino acid sequence lacked homology to previously characterized proteins and did not contain known functional motifs. Normal MLF1 transcripts were expressed in a variety of tissues, most abundantly in testis, ovary, skeletal muscle, heart, kidney and colon. Anti-MLF1 antibodies detected the wild-type 31 kDa protein in K562 and HEL erythroleukemia cell lines, but not in HL-60, U937 or KG-1 myeloid leukemia lines. By contrast, t(3;5)-positive leukemia cells expressed a 54 kDa NPM-MLF1 protein, but not normal MLF1. Immunostaining experiments indicated that MLF1 is normally located in the cytoplasm, whereas NPM-MLF1 is targeted to the nucleus, with highest levels in the nucleolus. The nuclear/nucleolar localization of NPM-MLF1 mirrors that of NPM, indicating that NPM trafficking signals direct MLF1 to an inappropriate cellular compartment in myeloid leukemia cells.

The flavonoid tangeretin activates the unfolded protein response and synergizes with imatinib in the erythroleukemia cell line K562.

PubMed

Lust, Sofie; Vanhoecke, Barbara; Van Gele, Mireille; Philippé, Jan; Bracke, Marc; Offner, Fritz

2010-06-01

We explored the mechanism of cell death of the polymethoxyflavone tangeretin (TAN) in K562 breakpoint cluster region-abelson murine leukemia (Bcr-Abl+) cells. Flow cytometric analysis showed that TAN arrested the cells in the G(2)/M phase and stimulated an accumulation of the cells in the sub-G(0) phase. TAN-induced cell death was evidenced by poly(ADP)-ribose polymerase cleavage, DNA laddering fragmentation, activation of the caspase cascade and downregulation of the antiapoptotic proteins Mcl-1 and Bcl-x(L). Pretreatment with the pancaspase inhibitor Z-VAD-FMK_blocked caspase activation and cell cycle arrest but did not inhibit apoptosis which suggest that other cell killing mechanisms like endoplasmic reticulum (ER)-associated cell death pathways could be involved. We demonstrated that TAN-induced apoptosis was preceded by a rapid activation of the proapoptotic arm of the unfolded protein response, namely PKR-like ER kinase. This was accompanied by enhanced levels of glucose-regulated protein of 78 kDa and of spliced X-box binding protein 1. Furthermore, TAN sensitized K562 cells to the cell killing effects of imatinib via an apoptotic mechanism. In conclusion, our results suggest that TAN is able to induce apoptosis in Bcr-Abl+ cells via cell cycle arrest and the induction of the unfolded protein response, and has synergistic cytotoxicity with imatinib.

A role for FOXO1 in BCR–ABL1-independent tyrosine kinase inhibitor resistance in chronic myeloid leukemia

PubMed Central

Wagle, M; Eiring, A M; Wongchenko, M; Lu, S; Guan, Y; Wang, Y; Lackner, M; Amler, L; Hampton, G; Deininger, M W; O'Hare, T; Yan, Y

2016-01-01

Chronic myeloid leukemia (CML) patients who relapse on imatinib due to acquired ABL1 kinase domain mutations are successfully treated with second-generation ABL1-tyrosine kinase inhibitors (ABL-TKIs) such as dasatinib, nilotinib or ponatinib. However, ~40% of relapsed patients have uncharacterized BCR–ABL1 kinase-independent mechanisms of resistance. To identify these mechanisms of resistance and potential treatment options, we generated ABL-TKI-resistant K562 cells through prolonged sequential exposure to imatinib and dasatinib. Dual-resistant K562 cells lacked BCR–ABL1 kinase domain mutations, but acquired other genomic aberrations that were characterized by next-generation sequencing and copy number analyses. Proteomics showed that dual-resistant cells had elevated levels of FOXO1, phospho-ERK and BCL-2, and that dasatinib no longer inhibited substrates of the PI3K/AKT pathway. In contrast to parental cells, resistant cells were sensitive to growth inhibition and apoptosis induced by the class I PI3K inhibitor, GDC-0941 (pictilisib), which also induced FOXO1 nuclear translocation. FOXO1 was elevated in a subset of primary specimens from relapsed CML patients lacking BCR–ABL1 kinase domain mutations, and these samples were responsive to GDC-0941 treatment ex vivo. We conclude that elevated FOXO1 contributes to BCR–ABL1 kinase-independent resistance experienced by these CML patients and that PI3K inhibition coupled with BCR–ABL1 inhibition may represent a novel therapeutic approach. PMID:27044711

A role for FOXO1 in BCR-ABL1-independent tyrosine kinase inhibitor resistance in chronic myeloid leukemia.

PubMed

Wagle, M; Eiring, A M; Wongchenko, M; Lu, S; Guan, Y; Wang, Y; Lackner, M; Amler, L; Hampton, G; Deininger, M W; O'Hare, T; Yan, Y

2016-07-01

Chronic myeloid leukemia (CML) patients who relapse on imatinib due to acquired ABL1 kinase domain mutations are successfully treated with second-generation ABL1-tyrosine kinase inhibitors (ABL-TKIs) such as dasatinib, nilotinib or ponatinib. However, ~40% of relapsed patients have uncharacterized BCR-ABL1 kinase-independent mechanisms of resistance. To identify these mechanisms of resistance and potential treatment options, we generated ABL-TKI-resistant K562 cells through prolonged sequential exposure to imatinib and dasatinib. Dual-resistant K562 cells lacked BCR-ABL1 kinase domain mutations, but acquired other genomic aberrations that were characterized by next-generation sequencing and copy number analyses. Proteomics showed that dual-resistant cells had elevated levels of FOXO1, phospho-ERK and BCL-2, and that dasatinib no longer inhibited substrates of the PI3K/AKT pathway. In contrast to parental cells, resistant cells were sensitive to growth inhibition and apoptosis induced by the class I PI3K inhibitor, GDC-0941 (pictilisib), which also induced FOXO1 nuclear translocation. FOXO1 was elevated in a subset of primary specimens from relapsed CML patients lacking BCR-ABL1 kinase domain mutations, and these samples were responsive to GDC-0941 treatment ex vivo. We conclude that elevated FOXO1 contributes to BCR-ABL1 kinase-independent resistance experienced by these CML patients and that PI3K inhibition coupled with BCR-ABL1 inhibition may represent a novel therapeutic approach.

4-Nerolidylcatechol: apoptosis by mitochondrial mechanisms with reduction in cyclin D1 at G0/G1 stage of the chronic myelogenous K562 cell line.

PubMed

Benfica, Polyana Lopes; Ávila, Renato Ivan de; Rodrigues, Bruna Dos Santos; Cortez, Alane Pereira; Batista, Aline Carvalho; Gaeti, Marilisa Pedroso Nogueira; Lima, Eliana Martins; Rezende, Kênnia Rocha; Valadares, Marize Campos

2017-12-01

4-Nerolidylcatechol (4-NRC) has showed antitumor potential through apoptosis. However, its apoptotic mechanisms are still unclear, especially in leukemic cells. To evaluate the cytotoxic potential of 4-NRC and its cell death pathways in p53-null K562 leukemic cells. Cytotoxicity of 4-NRC (4.17-534.5 μM) over 24 h of exposure was evaluated by MTT assay. 4-NRC-induced apoptosis in K562 cells was investigated by phosphatidylserine (PS) externalization, cell cycle, sub-G1, mitochondrial evaluation, cytochrome c, cyclin D1 and intracellular reactive oxygen species (ROS) levels, and caspase activity analysis. IC 50 values obtained were 11.40, 27.31, 15.93 and 15.70 μM for lymphocytes, K562, HL-60 and Jurkat cells, respectively. In K562 cells, 4-NRC (27 μM) promoted apoptosis as verified by cellular morphological changes, a significant increase in PS externalization and sub-G1 cells. Moreover, it significantly arrested the cells at the G0/G1 phase due to a reduction in cyclin D1 expression. These effects of 4-NRC also significantly promoted a reduction in mitochondrial activity and membrane depolarization, accumulation of cytosolic cytochrome c and ROS overproduction. Additionally, it triggered an increase in caspases -3/7, -8 and -9 activities. When the cells were pretreated with N-acetyl-l-cysteine ROS scavenger, 4-NRC-induced apoptosis was partially blocked, which suggests that it exerts cytotoxicity though not exclusively through ROS-mediated mechanisms. 4-NRC has antileukemic properties, inducing apoptosis mediated by mitochondrial-dependent mechanisms with cyclin D1 inhibition. Given that emerging treatment concepts include novel combinations of well-known agents, 4-NRC could offer a promising alternative for chemotherapeutic combinations to maximize tumour suppression.

Development and characterization of K562 cell clones expressing BCL11A-XL: Decreased hemoglobin production with fetal hemoglobin inducers and its rescue with mithramycin

PubMed Central

Finotti, Alessia; Gasparello, Jessica; Breveglieri, Giulia; Cosenza, Lucia Carmela; Montagner, Giulia; Bresciani, Alberto; Altamura, Sergio; Bianchi, Nicoletta; Martini, Elisa; Gallerani, Eleonora; Borgatti, Monica; Gambari, Roberto

2015-01-01

Induction of fetal hemoglobin (HbF) is considered a promising strategy in the treatment of β-thalassemia, in which production of adult hemoglobin (HbA) is impaired by mutations affecting the β-globin gene. Recent results indicate that B-cell lymphoma/leukemia 11A (BCL11A) is a major repressor of γ-globin gene expression. Therefore, disrupting the binding of the BCL11A transcriptional repressor complex to the γ-globin gene promoter provides a novel approach for inducing expression of the γ-globin genes. To develop a cellular screening system for the identification of BCL11A inhibitors, we produced K562 cell clones with integrated copies of a BCL11A-XL expressing vector. We characterized 12 K562 clones expressing different levels of BCL11A-XL and found that a clear inverse relationship does exist between the levels of BCL11A-XL and the extent of hemoglobinization induced by a panel of HbF inducers. Using mithramycin as an inducer, we found that this molecule was the only HbF inducer efficient in rescuing the ability to differentiate along the erythroid program, even in K562 cell clones expressing high levels of BCL11A-XL, suggesting that BCL11A-XL activity is counteracted by mithramycin. PMID:26342260

Comparison of different methods for erythroid differentiation in the K562 cell line.

PubMed

Shariati, Laleh; Modaress, Mehran; Khanahmad, Hossein; Hejazi, Zahra; Tabatabaiefar, Mohammad Amin; Salehi, Mansoor; Modarressi, Mohammad Hossein

2016-08-01

To compare methods for erythroid differentiation of K562 cells that will be promising in the treatment of beta-thalassemia by inducing γ-globin synthesis. Cells were treated separately with: RPMI 1640 medium without glutamine, RPMI 1640 medium without glutamine supplemented with 1 mM sodium butyrate, RPMI 1640 medium supplemented with 1 mM sodium butyrate, 25 µg cisplatin/ml, 0.1 µg cytosine arabinoside/ml. The highest differentiation (84 %) with minimum toxicity was obtained with cisplatin at 15 µg /ml. Real-time RT-PCR showed that expression of the γ-globin gene was significantly higher in the cells differentiated with cisplatin compared to undifferentiated cells (P < 0.001). Cisplatin is useful in the experimental therapy of ß-globin gene defects and can be considered for examining the basic mechanism of γ-reactivation.

Targeted Blockage of Signal Transducer and Activator of Transcription 5 Signaling Pathway with Decoy Oligodeoxynucleotides Suppresses Leukemic K562 Cell Growth

PubMed Central

Wang, Xiaozhong; Zeng, Jianming; Shi, Mei; Zhao, Shiqiao; Bai, Weijun; Cao, Weixi; Tu, Zhiguang; Huang, Zonggan

2011-01-01

The protein signal transducer and activator of transcription 5 (STAT5) of the JAK/STAT pathway is constitutively activated because of its phosphorylation by tyrosine kinase activity of fusion protein BCR-ABL in chronic myelogenous leukemia (CML) cells. This study investigated the potential therapeutic effect of STAT5 decoy oligodeoxynucleotides (ODN) using leukemia K562 cells as a model. Our results showed that transfection of 21-mer-long STAT5 decoy ODN into K562 cells effectively inhibited cell proliferation and induced cell apoptosis. Further, STAT5 decoy ODN downregulated STAT5 targets bcl-xL, cyclinD1, and c-myc at both mRNA and protein levels in a sequence-specific manner. Collectively, these data demonstrate the therapeutic effect of blocking the STAT5 signal pathway by cis-element decoy for cancer characterized by constitutive STAT5 activation. Thus, our study provides support for STAT5 as a potential target downstream of BCR-ABL for CML treatment and helps establish the concept of targeting STAT5 by decoy ODN as a novel therapy approach for imatinib-resistant CML. PMID:21091189

Development and characterization of K562 cell clones expressing BCL11A-XL: Decreased hemoglobin production with fetal hemoglobin inducers and its rescue with mithramycin.

PubMed

Finotti, Alessia; Gasparello, Jessica; Breveglieri, Giulia; Cosenza, Lucia Carmela; Montagner, Giulia; Bresciani, Alberto; Altamura, Sergio; Bianchi, Nicoletta; Martini, Elisa; Gallerani, Eleonora; Borgatti, Monica; Gambari, Roberto

2015-12-01

Induction of fetal hemoglobin (HbF) is considered a promising strategy in the treatment of β-thalassemia, in which production of adult hemoglobin (HbA) is impaired by mutations affecting the β-globin gene. Recent results indicate that B-cell lymphoma/leukemia 11A (BCL11A) is a major repressor of γ-globin gene expression. Therefore, disrupting the binding of the BCL11A transcriptional repressor complex to the γ-globin gene promoter provides a novel approach for inducing expression of the γ-globin genes. To develop a cellular screening system for the identification of BCL11A inhibitors, we produced K562 cell clones with integrated copies of a BCL11A-XL expressing vector. We characterized 12 K562 clones expressing different levels of BCL11A-XL and found that a clear inverse relationship does exist between the levels of BCL11A-XL and the extent of hemoglobinization induced by a panel of HbF inducers. Using mithramycin as an inducer, we found that this molecule was the only HbF inducer efficient in rescuing the ability to differentiate along the erythroid program, even in K562 cell clones expressing high levels of BCL11A-XL, suggesting that BCL11A-XL activity is counteracted by mithramycin. Copyright © 2015 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

Technical Advance: Transcription factor, promoter, and enhancer utilization in human myeloid cells.

PubMed

Joshi, Anagha; Pooley, Christopher; Freeman, Tom C; Lennartsson, Andreas; Babina, Magda; Schmidl, Christian; Geijtenbeek, Teunis; Michoel, Tom; Severin, Jessica; Itoh, Masayoshi; Lassmann, Timo; Kawaji, Hideya; Hayashizaki, Yoshihide; Carninci, Piero; Forrest, Alistair R R; Rehli, Michael; Hume, David A

2015-05-01

The generation of myeloid cells from their progenitors is regulated at the level of transcription by combinatorial control of key transcription factors influencing cell-fate choice. To unravel the global dynamics of this process at the transcript level, we generated transcription profiles for 91 human cell types of myeloid origin by use of CAGE profiling. The CAGE sequencing of these samples has allowed us to investigate diverse aspects of transcription control during myelopoiesis, such as identification of novel transcription factors, miRNAs, and noncoding RNAs specific to the myeloid lineage. We further reconstructed a transcription regulatory network by clustering coexpressed transcripts and associating them with enriched cis-regulatory motifs. With the use of the bidirectional expression as a proxy for enhancers, we predicted over 2000 novel enhancers, including an enhancer 38 kb downstream of IRF8 and an intronic enhancer in the KIT gene locus. Finally, we highlighted relevance of these data to dissect transcription dynamics during progressive maturation of granulocyte precursors. A multifaceted analysis of the myeloid transcriptome is made available (www.myeloidome.roslin.ed.ac.uk). This high-quality dataset provides a powerful resource to study transcriptional regulation during myelopoiesis and to infer the likely functions of unannotated genes in human innate immunity. © The Author(s).

31 CFR 562.203 - Holding of funds in interest-bearing accounts; investment and reinvestment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... IRANIAN HUMAN RIGHTS ABUSES SANCTIONS REGULATIONS Prohibitions § 562.203 Holding of funds in interest... accounts; investment and reinvestment. 562.203 Section 562.203 Money and Finance: Treasury Regulations... the funds are invested in a money market fund or in U.S. Treasury bills. (2) For purposes of this...

31 CFR 562.203 - Holding of funds in interest-bearing accounts; investment and reinvestment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... IRANIAN HUMAN RIGHTS ABUSES SANCTIONS REGULATIONS Prohibitions § 562.203 Holding of funds in interest... accounts; investment and reinvestment. 562.203 Section 562.203 Money and Finance: Treasury Regulations... the funds are invested in a money market fund or in U.S. Treasury bills. (2) For purposes of this...

31 CFR 562.203 - Holding of funds in interest-bearing accounts; investment and reinvestment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... IRANIAN HUMAN RIGHTS ABUSES SANCTIONS REGULATIONS Prohibitions § 562.203 Holding of funds in interest... accounts; investment and reinvestment. 562.203 Section 562.203 Money and Finance: Treasury Regulations... the funds are invested in a money market fund or in U.S. Treasury bills. (2) For purposes of this...

31 CFR 562.203 - Holding of funds in interest-bearing accounts; investment and reinvestment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... IRANIAN HUMAN RIGHTS ABUSES SANCTIONS REGULATIONS Prohibitions § 562.203 Holding of funds in interest... accounts; investment and reinvestment. 562.203 Section 562.203 Money and Finance: Treasury Regulations... the funds are invested in a money market fund or in U.S. Treasury bills. (2) For purposes of this...

A Method for Identification and Analysis of Non-Overlapping Myeloid Immunophenotypes in Humans

PubMed Central

Gustafson, Michael P.; Lin, Yi; Maas, Mary L.; Van Keulen, Virginia P.; Johnston, Patrick B.; Peikert, Tobias; Gastineau, Dennis A.; Dietz, Allan B.

2015-01-01

The development of flow cytometric biomarkers in human studies and clinical trials has been slowed by inconsistent sample processing, use of cell surface markers, and reporting of immunophenotypes. Additionally, the function(s) of distinct cell types as biomarkers cannot be accurately defined without the proper identification of homogeneous populations. As such, we developed a method for the identification and analysis of human leukocyte populations by the use of eight 10-color flow cytometric protocols in combination with novel software analyses. This method utilizes un-manipulated biological sample preparation that allows for the direct quantitation of leukocytes and non-overlapping immunophenotypes. We specifically designed myeloid protocols that enable us to define distinct phenotypes that include mature monocytes, granulocytes, circulating dendritic cells, immature myeloid cells, and myeloid derived suppressor cells (MDSCs). We also identified CD123 as an additional distinguishing marker for the phenotypic characterization of immature LIN-CD33+HLA-DR- MDSCs. Our approach permits the comprehensive analysis of all peripheral blood leukocytes and yields data that is highly amenable for standardization across inter-laboratory comparisons for human studies. PMID:25799053

Selected terpenes from leaves of Ocimum basilicum L. induce hemoglobin accumulation in human K562 cells.

PubMed

Feriotto, Giordana; Marchetti, Nicola; Costa, Valentina; Torricelli, Piera; Beninati, Simone; Tagliati, Federico; Mischiati, Carlo

2018-06-01

Re-expression of fetal hemoglobin (HbF) was proposed as a possible therapeutic strategy for β-haemoglobinopathies. Although several inducers of HbF were tested in clinical trials, only hydroxyurea (HU) received FDA approval. Despite it produced adequate HbF levels only in half of HU-treated SCD patients, and was ineffective at all in β-thalassemia patients, beneficial effects of this approach suggested to continue in this direction identifying further molecules capable of inducing HbF. We tested the potential of essential oil isolated from Ocimum basilicum L. leaves (ObEO) in inducing hemoglobin biosynthesis. Initially, dose-dependent effect and kinetics of hemoglobin accumulation in K562 cells after treatment with ObEO were evaluated. ObEO induced dose-dependent hemoglobin accumulation superior to hydroxyurea and rapamycin and a strongest γ-globin mRNA expression. Terpenes composition of ObEO was studied by GC-MS. Three main constituents, linalool, eugenol and eucalyptol, represented about 75% of total. A blend of these three terpenes fully replicated the ObEO's biological effect, thus indicating that one of them or all together could be the active ingredients. When terpenes were tested individually, eugenol was the only one inducing stable hemoglobin accumulation, while eucalyptol and linalool produced only a small transient response. However, eugenol potential was strongly enhanced in the presence of eucalyptol and linalool, suggesting a synergistic effect on hemoglobin accumulation. By these results, the discovery of a new inducer and the interesting activity of a blend of major terpenes from ObOE on Hb accumulation could have positive fallouts on β-thalassemia and sickle cells anemia. Copyright © 2018 Elsevier B.V. All rights reserved.

32 CFR 562.6 - Responsibilities.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Responsibilities. 562.6 Section 562.6 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY ORGANIZED RESERVES RESERVE OFFICERS' TRAINING CORPS § 562.6 Responsibilities. (a) The Commanding General, US Army Military Personnel Center, 200...

32 CFR 562.2 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 3 2014-07-01 2014-07-01 false Applicability. 562.2 Section 562.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY ORGANIZED RESERVES RESERVE OFFICERS' TRAINING CORPS § 562.2 Applicability. This regulation applies to the program given at college level...

31 CFR 562.303 - Entity.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Entity. 562.303 Section 562.303 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS... § 562.303 Entity. The term entity means a partnership, association, trust, joint venture, corporation...

32 CFR 562.1 - Purpose.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 3 2014-07-01 2014-07-01 false Purpose. 562.1 Section 562.1 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY ORGANIZED RESERVES RESERVE OFFICERS' TRAINING CORPS § 562.1 Purpose. This regulation gives policies for conducting the Army's Senior Reserve Officers...

The development of a three-dimensional scaffold for ex vivo biomimicry of human acute myeloid leukaemia.

PubMed

Blanco, Teresa Mortera; Mantalaris, Athanasios; Bismarck, Alexander; Panoskaltsis, Nicki

2010-03-01

Acute myeloid leukaemia (AML) is a cancer of haematopoietic cells that develops in three-dimensional (3-D) bone marrow niches in vivo. The study of AML has been hampered by lack of appropriate ex vivo models that mimic this microenvironment. We hypothesised that fabrication and optimisation of suitable biomimetic scaffolds for culturing leukaemic cells ex vivo might facilitate the study of AML in its native 3-D niche. We evaluated the growth of three leukaemia subtype-specific cell lines, K-562, HL60 and Kasumi-6, on highly porous scaffolds fabricated from biodegradable and non-biodegradable polymeric materials, such as poly (L-lactic-co-glycolic acid) (PLGA), polyurethane (PU), poly (methyl-methacrylate), poly (D, L-lactade), poly (caprolactone), and polystyrene. Our results show that PLGA and PU supported the best seeding efficiency and leukaemic growth. Furthermore, the PLGA and PU scaffolds were coated with extracellular matrix (ECM) proteins, collagen type I (62.5 or 125 microg/ml) and fibronectin (25 or 50 microg/ml) to provide biorecognition signals. The 3 leukaemia subtype-specific lines grew best on PU scaffolds coated with 62.5 microg/ml collagen type I over 6 weeks in the absence of exogenous growth factors. In conclusion, PU-collagen scaffolds may provide a practical model to study the biology and treatment of primary AML in an ex vivo mimicry. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

32 CFR 562.4 - Objectives.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 3 2014-07-01 2014-07-01 false Objectives. 562.4 Section 562.4 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY ORGANIZED RESERVES RESERVE OFFICERS' TRAINING CORPS § 562.4 Objectives. The objectives of the ROTC program are to: (a) Attract, motivate, and prepare...

The multidrug resistance pumps are inhibited by silibinin and apoptosis induced in K562 and KCL22 leukemia cell lines.

PubMed

Noori-Daloii, Mohammad Reza; Saffari, Mojtaba; Raoofian, Reza; Yekaninejad, Mirsaeed; Dinehkabodi, Orkideh Saydi; Noori-Daloii, Ali Reza

2014-05-01

Silibinin have been introduced for several years as a potent antioxidant in the field of nutraceuticals. Based on wide persuasive effects of this drug, we have decided to investigate the effects of silibinin on chronic myelogenous leukemia (CML) in vitro models, K562 and KCL22 cell lines. Lactate dehydrogenase (LDH) release, microculture tetrazolium test (MTT assay) and real-time PCR were employed to evaluate the effects of silibinin on cell cytotoxicity, cell proliferation and expression of various multidrug resistance genes in these cell lines, respectively. Our results have shown that presence of silibinin has inhibitory effects on cell proliferation of K562 and KCL22 cell lines. Also, our data indicated that silibinin, in a dose-dependent manner with applying no cytotoxic effects, inhibited cell proliferation and reduced mRNA expression levels of some transporter genes e.g. MDR1, MRP3, MRP2, MRP1, MRP5, MRP4, ABCG2, ABCB11, MRP6 and MRP7. The multifarious in vitro inhibitory effects of silibinin are in agreement with growing body of evidence that silibinin would be an efficient anticancer agent in order to be used in multi-target therapy to prevail the therapeutic hold backs against CML. Copyright © 2014. Published by Elsevier Ltd.

32 CFR 562.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Definitions. 562.3 Section 562.3 National Defense... § 562.3 Definitions. The following terms apply to the Army's Senior Reserve Officers' Training Corps... installation. This is part of the advanced course and normally attended between Military Science (MS)-III and...

Influence of different metal ions on the ultrastructure, biochemical properties, and protein localization of the K562 cell nuclear matrix.

PubMed

Neri, L M; Bortul, R; Zweyer, M; Tabellini, G; Borgatti, P; Marchisio, M; Bareggi, R; Capitani, S; Martelli, A M

1999-06-01

The higher order of chromatin organization is thought to be determined by the nuclear matrix, a mainly proteinaceous structure that would act as a nucleoskeleton. The matrix is obtained from isolated nuclei by a series of extraction steps involving the use of high salt and nonspecific nucleases, which remove chromatin and other loosely bound components. It is currently under debate whether these structures, isolated in vitro by unphysiological extraction buffers, correspond to a nucleoskeleton existing in vivo. In most cell types investigated, the nuclear matrix does not spontaneously resist these extractions steps; rather, it must be stabilized before the application of extracting agents. In this study nuclei, isolated from K562 human erythroleukemia cells, were stabilized by incubation with different metal ions (Ca2+, Cu2+, Zn2+, Cd2+), and the matrix was obtained by extraction with 2 M NaCl. By means of ultrastructural analysis of the resulting structures, we determined that, except for Ca2+, all the other metals induced a stabilization of the matrix, which retained the inner fibrogranular network and residual nucleoli. The biochemical composition, analyzed by two-dimensional gel electrophoresis separation, exhibited a distinct matrix polypeptide pattern, characteristic of each type of stabilizing ion employed. We also investigated to what extent metal ions could maintain in the final structures the original distribution of three inner matrix components, i.e. NuMA, topoisomerase IIalpha, and RNP. Confocal microscopy analysis showed that only NuMa, and, to a lesser extent, topoisomerase IIalpha, were unaffected by stabilization with divalent ions. On the contrary, the fluorescent RNP patterns detected in the resulting matrices were always disarranged, irrespective of the stabilization procedure. These results indicate that several metal ions are powerful stabilizing agents of the nuclear matrix prepared from K562 erythroleukemia cells and also strengthen the

2-(trimethylammonium)ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate promotes megakaryocytic differentiation of myeloid leukaemia cells and primary human CD34⁺ haematopoietic stem cells.

PubMed

Limb, Jin-Kyung; Song, Doona; Jeon, Mijeong; Han, So-Yeop; Han, Gyoonhee; Jhon, Gil-Ja; Bae, Yun Soo; Kim, Jaesang

2015-04-01

In this study we showed that 2-(trimethylammonium)ethyl (R)-3-methoxy-3-oxo-2-stearamidopropyl phosphate [(R)-TEMOSPho], a derivative of an organic chemical identified from a natural product library, promotes highly efficient differentiation of megakaryocytes. Specifically, (R)-TEMOSPho induces cell cycle arrest, cell size increase and polyploidization from K562 and HEL cells, which are used extensively to model megakaryocytic differentiation. In addition, megakaryocyte-specific cell surface markers showed a dramatic increase in expression in response to (R)-TEMOSPho treatment. Importantly, we demonstrated that such megakaryocytic differentiation can also be induced from primary human CD34(+) haematopoietic stem cells. Activation of the PI3K-AKT pathway and, to a lesser extent, the MEK-ERK pathway appears to be required for this process, as blocking with specific inhibitors interferes with the differentiation of K562 cells. A subset of (R)-TEMOSPho-treated K562 cells undergoes spontaneous apoptosis and produces platelets that are apparently functional, as they bind to fibrinogen, express P-selectin and aggregate in response to SFLLRN and AYPGFK, the activating peptides for the PAR1 and PAR4 receptors, respectively. Taken together, these results indicate that (R)-TEMOSPho will be useful for dissecting the molecular mechanisms of megakaryocytic differentiation, and that this class of compounds represents potential therapeutic reagents for thrombocytopenia. Copyright © 2012 John Wiley & Sons, Ltd.

31 CFR 562.304 - Interest.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Interest. 562.304 Section 562.304... Definitions § 562.304 Interest. Except as otherwise provided in this part, the term interest, when used with respect to property (e.g., “an interest in property”), means an interest of any nature whatsoever, direct...

31 CFR 562.304 - Interest.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Interest. 562.304 Section 562.304... Definitions § 562.304 Interest. Except as otherwise provided in this part, the term interest, when used with respect to property (e.g., “an interest in property”), means an interest of any nature whatsoever, direct...

31 CFR 562.304 - Interest.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Interest. 562.304 Section 562.304... Definitions § 562.304 Interest. Except as otherwise provided in this part, the term interest, when used with respect to property (e.g., “an interest in property”), means an interest of any nature whatsoever, direct...

31 CFR 562.304 - Interest.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Interest. 562.304 Section 562.304... Definitions § 562.304 Interest. Except as otherwise provided in this part, the term interest, when used with respect to property (e.g., “an interest in property”), means an interest of any nature whatsoever, direct...

Differentiation and Characterization of Myeloid Cells

PubMed Central

Gupta, Dipti; Shah, Hetavi Parag; Malu, Krishnakumar; Berliner, Nancy; Gaines, Peter

2015-01-01

Recent molecular studies of myeloid differentiation have utilized several in vitro models of myelopoiesis, generated from either ex vivo differentiated bone marrow progenitors or induced immortalized myeloid cell lines. Ex vivo differentiation begins with an enriched population of bone marrow-derived hematopoietic stem cells generated by lineage depletion and/or positive selection for CD34+ antigen (human) or Sca-1+ (mouse) cells, which are then expanded and subsequently induced in vitro in a process that recapitulates normal myeloid development. Myeloid cell lines include two human leukemic cell lines, NB-4 and HL-60, which have been demonstrated to undergo retinoic acid–induced myeloid development, however, both cell lines exhibit defects in the upregulation of late-expressed neutrophil-specific genes. Multiple murine factor–dependent cell models of myelopoiesis are also available that express the full range of neutrophil maturation markers, including: 32Dcl3 cells, which undergo G-CSF-induced myeloid maturation, EML/EPRO cells, which develop into mature neutrophils in response to cytokines and retinoic acid, and ER-Hoxb8 cells, which undergo myeloid maturation upon removal of estradial in the maintenance medium. In this unit, the induction of myeloid maturation in each of these model systems is described, including their differentiation to either neutrophils or macrophages, if applicable. Commonly used techniques to test for myeloid characteristics of developing cells are also described, including flow cytometry and real time RT-PCR. Together, these assays provide a solid foundation for in vitro investigations of myeloid development with either human or mouse models. PMID:24510620

Myeloid leukemia factor: a return ticket from human leukemia to fly hematopoiesis.

PubMed

Gobert, Vanessa; Haenlin, Marc; Waltzer, Lucas

2012-01-01

Even though deregulation of human MLF1, the founding member of the Myeloid Leukemia Factor family, has been associated with acute myeloid leukemia, the function and mode of action of this family of genes have remained rather mysterious. Yet, recent findings in Drosophila shed new light on their biological activity and suggest that they play an important role in hematopoiesis and leukemia, notably by regulating the stability of RUNX transcription factors, another family of conserved proteins with prominent roles in normal and malignant blood cell development.

Part-1: Design, synthesis and biological evaluation of novel bromo-pyrimidine analogs as tyrosine kinase inhibitors.

PubMed

Munikrishnappa, Chandrashekar Suradhenupura; Puranik, Sangamesh B; Kumar, G V Suresh; Prasad, Y Rajendra

2016-08-25

A novel series of 5-bromo-pyrimidine derivatives (5a-l, 6a-h, 9a-m and 10a-d) were synthesized through multi step reactions starting from 5-bromo-2,4-dichloro pyrimidine. The newly synthesized compounds were characterized using elemental analysis and spectral data (IR, (1)H NMR, (13)C NMR and LC-MS) analysis. The titled compounds were evaluated for their in vitro cytotoxic activity against tumor cell lines panel consisted of HCT116 (human colon cancer cell line), A549 (human lung cancer cell line), K562 (human chronic myeloid leukemia cell line), U937 (human acute monocytic myeloid leukemia cell line), and L02 (human normal cell line) by using MTT assay Mosmann's method. As most of the compounds are highly potent against K562 cells, all the synthesized compounds were evaluated for Bcr/Abl tyrosine kinase inhibitory activity by using well-established ADP-Glo assay method. Dasatinib was utilized as positive control to validate in both biological evaluations. The biological activity revealed that the compounds 5c, 5e, 6g, 9e, 9f and 10c were potent Bcr/Abl kinase inhibitors among the titled compounds. Thus these compounds may be promising lead compounds to be developed as an alternative for current Dasatinib therapy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Pharmacological targeting of the PI3K/mTOR pathway alters the release of angioregulatory mediators both from primary human acute myeloid leukemia cells and their neighboring stromal cells.

PubMed

Reikvam, Håkon; Nepstad, Ina; Bruserud, Øystein; Hatfield, Kimberley Joanne

2013-06-01

Acute myeloid leukemia (AML) is a heterogeneous and aggressive malignancy with poor overall survival. Constitutive as well as cytokine-initiated activation of PI3K/Akt/mTOR signaling is a common feature of AML patients, and inhibition of this pathway is considered as a possible therapeutic strategy in AML. Human AML cells and different stromal cell populations were cultured under highly standardized in vitro conditions. We investigated the effects of mTOR inhibitors (rapamycin and temsirolimus) and PI3K inhibitors (GDC-0941 and 3-methyladenin (3-MA)) on cell proliferation and the constitutive release of angioregulatory mediators by AML and stromal cells. Primary human AML cells were heterogeneous, though most patients showed high CXCL8 levels and detectable release of CXCL10, Ang-1, HGF and MMP-9. Hierarchical clustering analysis showed that disruption of PI3K/Akt/mTOR pathways decreased AML cell release of CXCL8-11 for a large subset of patients, whereas the effects on other mediators were divergent. Various stromal cells (endothelial cells, fibroblasts, cells with osteoblastic phenotype) also showed constitutive release of angioregulatory mediators, and inhibitors of both the PI3K and mTOR pathway had anti-proliferative effects on stromal cells and resulted in decreased release of these angioregulatory mediators. PI3K and mTOR inhibitors can decrease constitutive cytokine release both by AML and stromal cells, suggesting potential direct and indirect antileukemic effects.

Pharmacological targeting of the PI3K/mTOR pathway alters the release of angioregulatory mediators both from primary human acute myeloid leukemia cells and their neighboring stromal cells

PubMed Central

Reikvam, Håkon; Nepstad, Ina; Bruserud, Øystein; Hatfield, Kimberley Joanne

2013-01-01

Acute myeloid leukemia (AML) is a heterogeneous and aggressive malignancy with poor overall survival. Constitutive as well as cytokine-initiated activation of PI3K/Akt/mTOR signaling is a common feature of AML patients, and inhibition of this pathway is considered as a possible therapeutic strategy in AML. Human AML cells and different stromal cell populations were cultured under highly standardized in vitro conditions. We investigated the effects of mTOR inhibitors (rapamycin and temsirolimus) and PI3K inhibitors (GDC-0941 and 3-methyladenin (3-MA)) on cell proliferation and the constitutive release of angioregulatory mediators by AML and stromal cells. Primary human AML cells were heterogeneous, though most patients showed high CXCL8 levels and detectable release of CXCL10, Ang-1, HGF and MMP-9. Hierarchical clustering analysis showed that disruption of PI3K/Akt/mTOR pathways decreased AML cell release of CXCL8-11 for a large subset of patients, whereas the effects on other mediators were divergent. Various stromal cells (endothelial cells, fibroblasts, cells with osteoblastic phenotype) also showed constitutive release of angioregulatory mediators, and inhibitors of both the PI3K and mTOR pathway had anti-proliferative effects on stromal cells and resulted in decreased release of these angioregulatory mediators. PI3K and mTOR inhibitors can decrease constitutive cytokine release both by AML and stromal cells, suggesting potential direct and indirect antileukemic effects. PMID:23919981

The Complexity of Targeting PI3K-Akt-mTOR Signalling in Human Acute Myeloid Leukaemia: The Importance of Leukemic Cell Heterogeneity, Neighbouring Mesenchymal Stem Cells and Immunocompetent Cells.

PubMed

Brenner, Annette K; Andersson Tvedt, Tor Henrik; Bruserud, Øystein

2016-11-11

Therapeutic targeting of PI3K-Akt-mTOR is considered a possible strategy in human acute myeloid leukaemia (AML); the most important rationale being the proapoptotic and antiproliferative effects of direct PI3K/mTOR inhibition observed in experimental studies of human AML cells. However, AML is a heterogeneous disease and these effects caused by direct pathway inhibition in the leukemic cells are observed only for a subset of patients. Furthermore, the final effect of PI3K-Akt-mTOR inhibition is modulated by indirect effects, i.e., treatment effects on AML-supporting non-leukemic bone marrow cells. In this article we focus on the effects of this treatment on mesenchymal stem cells (MSCs) and monocytes/macrophages; both these cell types are parts of the haematopoietic stem cell niches in the bone marrow. MSCs have unique membrane molecule and constitutive cytokine release profiles, and mediate their support through bidirectional crosstalk involving both cell-cell contact and the local cytokine network. It is not known how various forms of PI3K-Akt-mTOR targeting alter the molecular mechanisms of this crosstalk. The effect on monocytes/macrophages is also difficult to predict and depends on the targeted molecule. Thus, further development of PI3K-Akt-mTOR targeting into a clinical strategy requires detailed molecular studies in well-characterized experimental models combined with careful clinical studies, to identify patient subsets that are likely to respond to this treatment.

Expression of myeloid differentiation antigens on normal and malignant myeloid cells.

PubMed Central

Griffin, J D; Ritz, J; Nadler, L M; Schlossman, S F

1981-01-01

A series of monoclonal antibodies have been characterized that define four surface antigens (MY3, MY4, MY7, and MY8) of human myeloid cells. They were derived from a fusion of the NS-1 plasmacytoma cell line with splenocytes from a mouse immunized with human acute myelomonocytic leukemia cells. MY3 and MY4 are expressed by normal monocytes and by greater than 90% of patients with acute monocytic leukemia or acute myelomonocytic leukemia, but are detected much less often on other types of myeloid leukemia. MY7 is expressed by granulocytes, monocytes, and 5% of normal bone marrow cells. 79% of all acute myeloblastic leukemia (AML) patients tested (72 patients) express MY7 without preferential expression by any AML subtype. MY8 is expressed by normal monocytes, granulocytes, all peroxidase-positive bone marrow cells, and 50% of AML patients. MY3, MY4, and MY8 define myeloid differentiation antigens in that they are not detected on myeloid precursor cells and appear at discrete stages of differentiation. These antigens are not expressed by lymphocytes, erythrocytes, platelets, or lymphoid malignancies. The monoclonal antisera defining these antigens have been used to study differentiation of normal myeloid cells and malignant cell lines. Images PMID:6945311

Synergistic inhibitory effects of deferasirox in combination with decitabine on leukemia cell lines SKM-1, THP-1, and K-562.

PubMed

Li, Nianyi; Chen, Qinfen; Gu, Jingwen; Li, Shuang; Zhao, Guangjie; Wang, Wei; Wang, Zhicheng; Wang, Xiaoqin

2017-05-30

A multi-center study from the French Myelodysplastic Syndrome (MDS) Group confirmed that iron chelation therapy is an independent prognostic factor that can increase the survival rate of patients who are suffering from transfusion-dependent low-risk MDS. In this study, we aimed to explore this clinical phenomena in vitro, by exploring the synergistic effect of the iron chelator Deferasirox (DFX) and the DNA methyl transferase inhibitor Decitabine (DAC) in the leukemia cell lines SKM-1, THP-1, and K-562. Treatment with both DFX or DAC promoted apoptosis, induced cell cycle arrest, and inhibited proliferation in all three of these cell lines. The combination of DFX and DAC was much greater than the effect of using either drug alone. DFX showed a synergistic effect with DAC on cell apoptosis in all three cell lines and on cell cycle arrest at the G0/G1 phase in K-562 cells. DFX decreased the ROS levels to varying degrees. In contrast, DAC increased ROS levels and an increase in ROS was also noted when the two drugs were used in combination. Treatment of cells with DAC induced re-expression of ABAT, APAF-1, FADD, HJV, and SMPD3, presumably through demethylation. However the combination of DAC and DFX just had strong synergistic effect on the re-expression of HJV.

Synergistic inhibitory effects of deferasirox in combination with decitabine on leukemia cell lines SKM-1, THP-1, and K-562

PubMed Central

Li, Nianyi; Chen, Qinfen; Gu, Jingwen; Li, Shuang; Zhao, Guangjie; Wang, Wei; Wang, Zhicheng; Wang, Xiaoqin

2017-01-01

A multi-center study from the French Myelodysplastic Syndrome (MDS) Group confirmed that iron chelation therapy is an independent prognostic factor that can increase the survival rate of patients who are suffering from transfusion-dependent low-risk MDS. In this study, we aimed to explore this clinical phenomena in vitro, by exploring the synergistic effect of the iron chelator Deferasirox (DFX) and the DNA methyl transferase inhibitor Decitabine (DAC) in the leukemia cell lines SKM-1, THP-1, and K-562. Treatment with both DFX or DAC promoted apoptosis, induced cell cycle arrest, and inhibited proliferation in all three of these cell lines. The combination of DFX and DAC was much greater than the effect of using either drug alone. DFX showed a synergistic effect with DAC on cell apoptosis in all three cell lines and on cell cycle arrest at the G0/G1 phase in K-562 cells. DFX decreased the ROS levels to varying degrees. In contrast, DAC increased ROS levels and an increase in ROS was also noted when the two drugs were used in combination. Treatment of cells with DAC induced re-expression of ABAT, APAF-1, FADD, HJV, and SMPD3, presumably through demethylation. However the combination of DAC and DFX just had strong synergistic effect on the re-expression of HJV. PMID:28388554

Imatinib mesylate (STI571) decreases the vascular endothelial growth factor plasma concentration in patients with chronic myeloid leukemia.

PubMed

Legros, Laurence; Bourcier, Christine; Jacquel, Arnaud; Mahon, François-Xavier; Cassuto, Jill-Patrice; Auberger, Patrick; Pagès, Gilles

2004-07-15

Increased angiogenesis in bone marrow (BM) is one of the characteristics of chronic myeloid leukemia (CML), a clonal myeloproliferative disorder that expresses a chimeric Bcr/Abl protein. Recently, the therapeutic strategy in CML has been totally modified with the development of a new drug: imatinib mesylate (STI571), a specific inhibitor of Bcr/Abl tyrosine kinase activity. The aim of our study was to determine, in patients with CML, the capacity of imatinib mesylate to modulate one of the most potent regulators of angiogenesis, the vascular endothelial growth factor (VEGF). In newly diagnosed CML, we observed significantly increased VEGF secretion by CML BM cells and significantly increased VEGF plasma concentrations. We showed that low plasma VEGF concentrations could be one of the characteristics of complete cytogenetic remission. To understand the molecular mechanisms leading to the inhibition of VEGF production by imatinib, we focused our experiments on the human cell line K562, which is Bcr/Abl positive. We demonstrated that imatinib inhibits VEGF gene transcription by targeting the Sp1 and Sp3 transcription factors. Taken together, our results highlight the potential prognostic value of VEGF concentrations in evaluating the evolution of CML patients treated with imatinib.

The topoisomerase II inhibitor voreloxin causes cell cycle arrest and apoptosis in myeloid leukemia cells and acts in synergy with cytarabine

PubMed Central

Walsby, Elisabeth J.; Coles, Steven J.; Knapper, Steven; Burnett, Alan K.

2011-01-01

Background Topoisomerase II is essential for the maintenance of DNA integrity and the survival of proliferating cells. Topoisomerase II poisons, including etoposide and doxorubicin, inhibit enzyme-mediated DNA ligation causing the accumulation of double-stranded breaks and have been front-line drugs for the treatment of leukemia for many years. Voreloxin is a first-in-class anti-cancer quinolone derivative that intercalates DNA and inhibits topoisomerase II. The efficacy and mechanisms of action of voreloxin in acute myeloid leukaemia were addressed in this study. Design and Methods Primary acute myeloid leukemia blasts (n = 88) and myeloid cell lines were used in vitro to study voreloxin through viability assays to assess cell killing and synergy with other drugs. Apoptosis and cell cycling were assessed by flow cytometry. DNA relaxation assays were utilized to determine that voreloxin was active on topoisomerase II. Results The mean lethal dose 50% (LD50) (± standard deviation) of voreloxin for primary acute myeloid leukemia blasts was 2.30 μM (± 1.87). Synergy experiments between voreloxin and cytarabine identified synergism in 22 of 25 primary acute myeloid leukemia samples tested, with a mean combination index of 0.79. Apoptosis was shown to increase in a dose-dependent manner. Furthermore, voreloxin was active in the p53-null K562 cell line suggesting that the action of voreloxin is not affected by p53 status. The action of voreloxin on topoisomerase II was confirmed using a DNA relaxation assay. Conclusions Voreloxin may provide an interesting addition to the cache of drugs available for the treatment of acute myeloid leukemia, a disease with a poor long-term survival. In addition to its potent action as a single agent in dividing cells, the synergy we demonstrated between voreloxin and cytarabine recommends further investigation of this topoisomerase II inhibitor. PMID:21134979

32 CFR 562.7 - Program information.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 3 2014-07-01 2014-07-01 false Program information. 562.7 Section 562.7 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY ORGANIZED RESERVES RESERVE OFFICERS' TRAINING CORPS § 562.7 Program information. (a) The Senior ROTC is conducted at military colleges...

32 CFR 562.7 - Program information.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 3 2012-07-01 2009-07-01 true Program information. 562.7 Section 562.7 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY ORGANIZED RESERVES RESERVE OFFICERS' TRAINING CORPS § 562.7 Program information. (a) The Senior ROTC is conducted at military colleges, civilian...

31 CFR 562.101 - Relation of this part to other laws and regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Relation of this part to other laws and regulations. 562.101 Section 562.101 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY IRANIAN HUMAN RIGHTS...

31 CFR 562.101 - Relation of this part to other laws and regulations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Relation of this part to other laws and regulations. 562.101 Section 562.101 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY IRANIAN HUMAN RIGHTS...

31 CFR 562.101 - Relation of this part to other laws and regulations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Relation of this part to other laws and regulations. 562.101 Section 562.101 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY IRANIAN HUMAN RIGHTS...

31 CFR 562.101 - Relation of this part to other laws and regulations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Relation of this part to other laws and regulations. 562.101 Section 562.101 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY IRANIAN HUMAN RIGHTS...

31 CFR 562.309 - United States.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false United States. 562.309 Section 562.309 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN... Definitions § 562.309 United States. The term United States means the United States, its territories and...

31 CFR 562.309 - United States.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false United States. 562.309 Section 562.309 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN... Definitions § 562.309 United States. The term United States means the United States, its territories and...

31 CFR 562.309 - United States.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false United States. 562.309 Section 562.309 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN... Definitions § 562.309 United States. The term United States means the United States, its territories and...

31 CFR 562.309 - United States.

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2013-07-01

... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false United States. 562.309 Section 562.309 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN... Definitions § 562.309 United States. The term United States means the United States, its territories and...

31 CFR 56.2 - Sales price.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Sales price. 56.2 Section 56.2 Money and Finance: Treasury Regulations Relating to Money and Finance DOMESTIC GOLD AND SILVER OPERATIONS SALE OF SILVER § 56.2 Sales price. Sales of silver will be at prices offered through the competitive...

31 CFR 56.2 - Sales price.

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2013-07-01

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31 CFR 56.2 - Sales price.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Sales price. 56.2 Section 56.2 Money and Finance: Treasury Regulations Relating to Money and Finance MONETARY OFFICES, DEPARTMENT OF THE TREASURY DOMESTIC GOLD AND SILVER OPERATIONS SALE OF SILVER § 56.2 Sales price. Sales of silver will be at...

31 CFR 56.2 - Sales price.

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2014-07-01

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31 CFR 56.2 - Sales price.

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2011-07-01

... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Sales price. 56.2 Section 56.2 Money and Finance: Treasury Regulations Relating to Money and Finance MONETARY OFFICES, DEPARTMENT OF THE TREASURY DOMESTIC GOLD AND SILVER OPERATIONS SALE OF SILVER § 56.2 Sales price. Sales of silver will be at...

Clonal type I interferon-producing and dendritic cell precursors are contained in both human lymphoid and myeloid progenitor populations.

PubMed

Chicha, Laurie; Jarrossay, David; Manz, Markus G

2004-12-06

Because of different cytokine responsiveness, surface receptor, and transcription factor expression, human CD11c(-) natural type I interferon-producing cells (IPCs) and CD11c(+) dendritic cells were thought to derive through lymphoid and myeloid hematopoietic developmental pathways, respectively. To directly test this hypothesis, we used an in vitro assay allowing simultaneous IPC, dendritic cell, and B cell development and we tested lymphoid and myeloid committed hematopoietic progenitor cells for their developmental capacity. Lymphoid and common myeloid and granulocyte/macrophage progenitors were capable of developing into both functional IPCs, expressing gene transcripts thought to be associated with lymphoid lineage development, and into dendritic cells. However, clonal progenitors for both populations were about fivefold more frequent within myeloid committed progenitor cells. Thus, in humans as in mice, natural IPC and dendritic cell development robustly segregates with myeloid differentiation. This would fit with natural interferon type I-producing cell and dendritic cell activity in innate immunity, the evolutionary older arm of the cellular immune system.

Clonal Type I Interferon–producing and Dendritic Cell Precursors Are Contained in Both Human Lymphoid and Myeloid Progenitor Populations

PubMed Central

Chicha, Laurie; Jarrossay, David; Manz, Markus G.

2004-01-01

Because of different cytokine responsiveness, surface receptor, and transcription factor expression, human CD11c− natural type I interferon–producing cells (IPCs) and CD11c+ dendritic cells were thought to derive through lymphoid and myeloid hematopoietic developmental pathways, respectively. To directly test this hypothesis, we used an in vitro assay allowing simultaneous IPC, dendritic cell, and B cell development and we tested lymphoid and myeloid committed hematopoietic progenitor cells for their developmental capacity. Lymphoid and common myeloid and granulocyte/macrophage progenitors were capable of developing into both functional IPCs, expressing gene transcripts thought to be associated with lymphoid lineage development, and into dendritic cells. However, clonal progenitors for both populations were about fivefold more frequent within myeloid committed progenitor cells. Thus, in humans as in mice, natural IPC and dendritic cell development robustly segregates with myeloid differentiation. This would fit with natural interferon type I–producing cell and dendritic cell activity in innate immunity, the evolutionary older arm of the cellular immune system. PMID:15557348

Inhibition of the mitochondrial protease, ClpP, as a therapeutic strategy for human acute myeloid leuekmia

PubMed Central

Cole, Alicia; Wang, Zezhou; Coyaud, Etienne; Voisin, Veronique; Gronda, Marcela; Jitkova, Yulia; Mattson, Rachel; Hurren, Rose; Babovic, Sonja; Maclean, Neil; Restall, Ian; Wang, Xiaoming; Jeyaraju, Danny V.; Sukhai, Mahadeo A.; Prabha, Swayam; Bashir, Shaheena; Ramakrishnan, Ashwin; Leung, Elisa; Qia, Yi Hua; Zhang, Nianxian; Combes, Kevin R.; Ketela, Troy; Lin, Fengshu; Houry, Walid A.; Aman, Ahmed; Al-awar, Rima; Zheng, Wei; Wienholds, Erno; Xu, Chang Jiang; Dick, John; Wang, Jean C.Y.; Moffat, Jason; Minden, Mark D.; Eaves, Connie J.; Bader, Gary D.; Hao, Zhenyue; Kornblau, Steven M.; Raught, Brian; Schimmer, Aaron D.

2015-01-01

Summary From an shRNA screen, we identified ClpP as a member of the mitochondrial proteome whose knockdown reduced the viability of K562 leukemic cells. Expression of this mitochondrial protease that has structural similarity to the cytoplasmic proteosome is increased in the leukemic cells from approximately half of patients with AML. Genetic or chemical inhibition of ClpP killed cells from both human AML cell lines and primary samples in which the cells showed elevated ClpP expression, but did not affect their normal counterparts. Importantly, Clpp knockout mice were viable with normal hematopoiesis. Mechanistically, we found ClpP interacts with mitochondrial respiratory chain proteins and metabolic enzymes, and knockdown of ClpP in leukemic cells inhibited oxidative phosphorylation and mitochondrial metabolism. PMID:26058080

Antagonism of SET using OP449 enhances the efficacy of tyrosine kinase inhibitors and overcome drug resistance in myeloid leukemia

PubMed Central

Agarwal, Anupriya; MacKenzie, Ryan J.; Pippa, Raffaella; Eide, Christopher A.; Oddo, Jessica; Tyner, Jeffrey W.; Sears, Rosalie; Vitek, Michael P.; Odero, María D.; Christensen, Dale; Druker, Brian J.

2014-01-01

Purpose The SET oncoprotein, a potent inhibitor of the protein phosphatase 2A (PP2A), is overexpressed in leukemia. We evaluated the efficacy of SET antagonism in chronic myeloid leukemia (CML) and acute myeloid leukemia (AML) cell lines, a murine leukemia model, and primary patient samples using OP449, a specific, cell-penetrating peptide that antagonizes SET's inhibition of PP2A. Experimental Design In vitro cytotoxicity and specificity of OP449 in CML and AML cell lines and primary samples were measured using proliferation, apoptosis and colonogenic assays. Efficacy of target inhibition by OP449 is evaluated by immunoblotting and PP2A assay. In vivo antitumor efficacy of OP449 was measured in human HL-60 xenografted murine model. Results We observed that OP449 inhibited growth of CML cells including those from patients with blastic phase disease and patients harboring highly drug-resistant BCR-ABL1 mutations. Combined treatment with OP449 and ABL1 tyrosine kinase inhibitors was significantly more cytotoxic to K562 cells and primary CD34+ CML cells. SET protein levels remained unchanged with OP449 treatment, but BCR-ABL1-mediated downstream signaling was significantly inhibited with the degradation of key signaling molecules such as BCR-ABL1, STAT5, and AKT. Similarly, AML cell lines and primary patient samples with various genetic lesions showed inhibition of cell growth after treatment with OP449 alone or in combination with respective kinase inhibitors. Finally, OP449 reduced the tumor burden of mice xenografted with human leukemia cells. Conclusions We demonstrate a novel therapeutic paradigm of SET antagonism using OP449 in combination with tyrosine kinase inhibitors for the treatment of CML and AML. PMID:24436473

Five novel naphthylisoquinoline alkaloids with growth inhibitory activities against human leukemia cells HL-60, K562 and U937 from stems and leaves of Ancistrocladus tectorius.

PubMed

Jiang, Chao; Li, Zhan-Lin; Gong, Ping; Kang, Sheng-Li; Liu, Ming-Sheng; Pei, Yue-Hu; Jing, Yong-Kui; Hua, Hui-Ming

2013-12-01

Two new 7,6'-coupled naphthylisoquinolines, namely ancistrotectorines A (1) and B (2), two new 5,3'-coupled naphthylisoquinolines, namely ancistrotectorines C (3) and D (4), and one new 7,8-coupled naphthylisoquinoline, namely ancistrotectorine E (5), together with 9 known naphthylisoquinoline alkaloids, hamatine (6), ancistrobertsonine B (7), ancistrocladinine (8), hamatinine (9), ancistrotanzanine A (10), ancistrotanzanine B (11), ancistrotectoriline B (12), 7-epi-ancistrobrevine D (13), and ancistrotectorine (14), were isolated from the 70% EtOH extract of Ancistrocladus tectorius. Their structures were elucidated based on the extensive analysis of spectroscopic data (1D, 2D NMR and MS). Compound 5 exhibited inhibitory activities against HL-60, K562 and U937 cell lines with IC50 values of 1.70, 4.18 and 2.56 μM respectively. © 2013.

In-vitro antitumor activity evaluation of hyperforin derivatives.

PubMed

Sun, Feng; Liu, Jin-Yun; He, Feng; Liu, Zhong; Wang, Rui; Wang, Dong-Mei; Wang, Yi-Fei; Yang, De-Po

2011-08-01

The derivatives of hyperforin, namely hyperforin acetate (2), 17,18,22,23,27,28,32,33-octahydrohyperforin acetate (3), and N,N-dicyclohexylamine salt of hyperforin (4), have been investigated for their antitumor properties. In-vitro studies demonstrated that 2 and 4 were active against HeLa (human cervical cancer), A375 (human malignant melanoma), HepG2 (human hepatocellular carcinoma), MCF-7 (human breast cancer), A549 (human nonsmall cell lung cancer), K562 (human chronic myeloid leukemia), and K562/ADR (human adriamycin-resistant K562) cell lines with IC(50) values in the range of 3.2-64.1 μM. The energy differences between highest occupied molecular orbital and lowest unoccupied molecular orbital of 2-4 were calculated to be 0.39778, 0.43106, and 0.30900 a.u., respectively, using the Gaussian 03 software package and ab initio method with the HF/6-311 G* basis set. The result indicated that the biological activity of 4 might be the strongest and that of 3 might be the weakest, which was in accordance with their corresponding antiproliferative effects against the tested tumor cell lines. Compound 4 caused cell cycle arrest at G2/M phase in flow cytometry experiment and induced apoptosis by 4',6-diamidino-2-phenylindole staining and Annexin V-FITC/PI (propidium iodide) double-labeled staining in HepG2 cells. The results indicated a potential for N,N-dicyclohexylamine salt of hyperforin as a new antitumor drug.

Multiplex CRISPR/Cas9-Based Genome Editing in Human Hematopoietic Stem Cells Models Clonal Hematopoiesis and Myeloid Neoplasia.

PubMed

Tothova, Zuzana; Krill-Burger, John M; Popova, Katerina D; Landers, Catherine C; Sievers, Quinlan L; Yudovich, David; Belizaire, Roger; Aster, Jon C; Morgan, Elizabeth A; Tsherniak, Aviad; Ebert, Benjamin L

2017-10-05

Hematologic malignancies are driven by combinations of genetic lesions that have been difficult to model in human cells. We used CRISPR/Cas9 genome engineering of primary adult and umbilical cord blood CD34 + human hematopoietic stem and progenitor cells (HSPCs), the cells of origin for myeloid pre-malignant and malignant diseases, followed by transplantation into immunodeficient mice to generate genetic models of clonal hematopoiesis and neoplasia. Human hematopoietic cells bearing mutations in combinations of genes, including cohesin complex genes, observed in myeloid malignancies generated immunophenotypically defined neoplastic clones capable of long-term, multi-lineage reconstitution and serial transplantation. Employing these models to investigate therapeutic efficacy, we found that TET2 and cohesin-mutated hematopoietic cells were sensitive to azacitidine treatment. These findings demonstrate the potential for generating genetically defined models of human myeloid diseases, and they are suitable for examining the biological consequences of somatic mutations and the testing of therapeutic agents. Copyright © 2017 Elsevier Inc. All rights reserved.

Phloridzin docosahexaenoate, a novel flavonoid derivative, suppresses growth and induces apoptosis in T-cell acute lymphoblastic leukemia cells.

PubMed

Arumuggam, Niroshaathevi; Melong, Nicole; Too, Catherine Kl; Berman, Jason N; Rupasinghe, Hp Vasantha

2017-01-01

The overall clinical outcome in T-cell acute lymphoblastic leukemia (T-ALL) can be improved by minimizing risk for treatment failure using effective pharmacological adjuvants. Phloridzin (PZ), a flavonoid precursor found in apple peels, was acylated with docosahexaenoic acid (DHA) yielding a novel ester known as phloridzin docosahexaenoate (PZ-DHA). Here, we have studied the cytotoxic effects of PZ-DHA on human leukemia cells using in vitro and in vivo models. The inhibitory effects of PZ-DHA were tested on human Jurkat T-ALL cells in comparison to K562 chronic myeloid leukemia (CML) cells and non-malignant murine T-cells. PZ-DHA, not PZ or DHA alone, reduced cell viability and ATP levels, increased intracellular LDH release, and caused extensive morphological alterations in both Jurkat and K562 cells. PZ-DHA also inhibited cell proliferation, and selectively induced apoptosis in Jurkat and K562 cells while sparing normal murine T-cells. The cytotoxic effects of PZ-DHA on Jurkat cells were associated with caspase activation, DNA fragmentation, and selective down-regulation of STAT3 phosphorylation. PZ-DHA significantly inhibited Jurkat cell proliferation in zebrafish larvae; however, the proliferation of K562 cells was not affected in vivo . We propose that PZ-DHA-induced cytotoxic response is selective towards T-ALL in the presence of a tumor-stromal microenvironment. Prospective studies evaluating the combinatorial effects of PZ-DHA with conventional chemotherapy for T-ALL are underway.

Phloridzin docosahexaenoate, a novel flavonoid derivative, suppresses growth and induces apoptosis in T-cell acute lymphoblastic leukemia cells

PubMed Central

Arumuggam, Niroshaathevi; Melong, Nicole; Too, Catherine KL; Berman, Jason N; Rupasinghe, HP Vasantha

2017-01-01

The overall clinical outcome in T-cell acute lymphoblastic leukemia (T-ALL) can be improved by minimizing risk for treatment failure using effective pharmacological adjuvants. Phloridzin (PZ), a flavonoid precursor found in apple peels, was acylated with docosahexaenoic acid (DHA) yielding a novel ester known as phloridzin docosahexaenoate (PZ-DHA). Here, we have studied the cytotoxic effects of PZ-DHA on human leukemia cells using in vitro and in vivo models. The inhibitory effects of PZ-DHA were tested on human Jurkat T-ALL cells in comparison to K562 chronic myeloid leukemia (CML) cells and non-malignant murine T-cells. PZ-DHA, not PZ or DHA alone, reduced cell viability and ATP levels, increased intracellular LDH release, and caused extensive morphological alterations in both Jurkat and K562 cells. PZ-DHA also inhibited cell proliferation, and selectively induced apoptosis in Jurkat and K562 cells while sparing normal murine T-cells. The cytotoxic effects of PZ-DHA on Jurkat cells were associated with caspase activation, DNA fragmentation, and selective down-regulation of STAT3 phosphorylation. PZ-DHA significantly inhibited Jurkat cell proliferation in zebrafish larvae; however, the proliferation of K562 cells was not affected in vivo. We propose that PZ-DHA-induced cytotoxic response is selective towards T-ALL in the presence of a tumor-stromal microenvironment. Prospective studies evaluating the combinatorial effects of PZ-DHA with conventional chemotherapy for T-ALL are underway. PMID:29312799

G-CSF Induces Membrane Expression of a Myeloperoxidase Glycovariant that Operates as an E-selectin Ligand on Human Myeloid Cells

PubMed Central

Silvescu, Cristina I.; Sackstein, Robert

2014-01-01

The host defense response critically depends on the production of leukocytes by the marrow and the controlled delivery of these cells to relevant sites of inflammation/infection. The cytokine granulocyte-colony stimulating factor (G-CSF) is commonly used therapeutically to augment neutrophil recovery following chemo/radiation therapy for malignancy, thereby decreasing infection risk. Although best known as a potent inducer of myelopoiesis, we previously reported that G-CSF also promotes the delivery of leukocytes to sites of inflammation by stimulating expression of potent E-selectin ligands, including an uncharacterized ∼65-kDa glycoprotein. To identify this ligand, we performed integrated biochemical analysis and mass spectrometry studies of G-CSF–treated primary human myeloid cells. Our studies show that this novel E-selectin ligand is a glycoform of the heavy chain component of the enzyme myeloperoxidase (MPO), a well-known lysosomal peroxidase. This specialized MPO glycovariant, referred to as “MPO–E-selectin ligand” (MPO–EL), is expressed on circulating G-CSF–mobilized leukocytes and is naturally expressed on blood myeloid cells in patients with febrile leukocytosis. In vitro biochemical studies show that G-CSF programs MPO–EL expression on human blood leukocytes and marrow myeloid cells via induction of N-linked sialofucosylations on MPO, with concomitant cell surface display of the molecule. MPO–EL is catalytically active and mediates angiotoxicity on human endothelial cells that express E-selectin. These findings thus define a G-CSF effect on MPO chemical biology that endows unsuspected functional versatility upon this enzyme, unveiling new perspectives on the biology of G-CSF and MPO, and on the role of E-selectin receptor/ligand interactions in leukocyte migration and vascular pathology. PMID:25002508

32 CFR 562.6 - Responsibilities.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 3 2014-07-01 2014-07-01 false Responsibilities. 562.6 Section 562.6 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY ORGANIZED RESERVES RESERVE OFFICERS... Stovall Street, Alexandria, VA 22332, is the adminstrator of the Department of the Army for ROTC. (b) The...

Identification of MS4A3 as a reliable marker for early myeloid differentiation in human hematopoiesis.

PubMed

Ishibashi, Tomohiko; Yokota, Takafumi; Satoh, Yusuke; Ichii, Michiko; Sudo, Takao; Doi, Yukiko; Ueda, Tomoaki; Nagate, Yasuhiro; Hamanaka, Yuri; Tanimura, Akira; Ezoe, Sachiko; Shibayama, Hirohiko; Oritani, Kenji; Kanakura, Yuzuru

2018-01-15

Information of myeloid lineage-related antigen on hematopoietic stem/progenitor cells (HSPCs) is important to clarify the mechanisms regulating hematopoiesis, as well as for the diagnosis and treatment of myeloid malignancies. We previously reported that special AT-rich sequence binding protein 1 (SATB1), a global chromatin organizer, promotes lymphoid differentiation from HSPCs. To search a novel cell surface molecule discriminating early myeloid and lymphoid differentiation, we performed microarray analyses comparing SATB1-overexpressed HSPCs with mock-transduced HSPCs. The results drew our attention to membrane-spanning 4-domains, subfamily A, member 3 (Ms4a3) as the most downregulated molecule in HSPCs with forced overexpression of SATB1. Ms4a3 expression was undetectable in hematopoietic stem cells, but showed a concomitant increase with progressive myeloid differentiation, whereas not only lymphoid but also megakaryocytic-erythrocytic progenitors were entirely devoid of Ms4a3 expression. Further analysis revealed that a subset of CD34 + CD38 + CD33 + progenitor population in human adult bone marrow expressed MS4A3, and those MS4A3 + progenitors only produced granulocyte/macrophage colonies, losing erythroid colony- and mixed colony-forming capacity. These results suggest that cell surface expression of MS4A3 is useful to distinguish granulocyte/macrophage lineage-committed progenitors from other lineage-related ones in early human hematopoiesis. In conclusion, MS4A3 is useful to monitor early stage of myeloid differentiation in human hematopoiesis. Copyright © 2017 Elsevier Inc. All rights reserved.

40 CFR 721.562 - Substituted alkylamine salt.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted alkylamine salt. 721.562 Section 721.562 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.562 Substituted alkylamine salt...

32 CFR 562.4 - Objectives.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 3 2010-07-01 2010-07-01 true Objectives. 562.4 Section 562.4 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY ORGANIZED RESERVES RESERVE OFFICERS' TRAINING CORPS... students with potential to serve as commissioned officers in the Regular Army or the US Army Reserve. (b...

Inhibition of DNA-dependent protein kinase catalytic subunit by small molecule inhibitor NU7026 sensitizes human leukemic K562 cells to benzene metabolite-induced apoptosis.

PubMed

You, Hao; Kong, Meng-meng; Wang, Li-ping; Xiao, Xiao; Liao, Han-lin; Bi, Zhuo-yue; Yan, Hong; Wang, Hong; Wang, Chun-hong; Ma, Qiang; Liu, Yan-qun; Bi, Yong-yi

2013-02-01

Benzene is an established leukotoxin and leukemogen in humans. We have previously reported that exposure of workers to benzene and to benzene metabolite hydroquinone in cultured cells induced DNA-dependent protein kinase catalytic subunit (DNA-PKcs) to mediate the cellular response to DNA double strand break (DSB) caused by DNA-damaging metabolites. In this study, we used a new, small molecule, a selective inhibitor of DNA-PKcs, 2-(morpholin-4-yl)-benzo[h]chomen-4-one (NU7026), as a probe to analyze the molecular events and pathways in hydroquinone-induced DNA DSB repair and apoptosis. Inhibition of DNA-PKcs by NU7026 markedly potentiated the apoptotic and growth inhibitory effects of hydroquinone in proerythroid leukemic K562 cells in a dose-dependent manner. Treatment with NU7026 did not alter the production of reactive oxygen species and oxidative stress by hydroquinone but repressed the protein level of DNA-PKcs and blocked the induction of the kinase mRNA and protein expression by hydroquinone. Moreover, hydroquinone increased the phosphorylation of Akt to activate Akt, whereas co-treatment with NU7026 prevented the activation of Akt by hydroquinone. Lastly, hydroquinone and NU7026 exhibited synergistic effects on promoting apoptosis by increasing the protein levels of pro-apoptotic proteins Bax and caspase-3 but decreasing the protein expression of anti-apoptotic protein Bcl-2. Taken together, the findings reveal a central role of DNA-PKcs in hydroquinone-induced hematotoxicity in which it coordinates DNA DSB repair, cell cycle progression, and apoptosis to regulate the response to hydroquinone-induced DNA damage.

In vitro testing of drug combinations employing nilotinib and alkylating agents with regard to pretransplant conditioning treatment of advanced-phase chronic myeloid leukemia.

PubMed

Radujkovic, Aleksandar; Luft, Thomas; Dreger, Peter; Ho, Anthony D; Jens Zeller, W; Fruehauf, Stefan; Topaly, Julian

2014-08-01

The prognosis of patients with advanced-phase chronic myeloid leukemia (CML) remains dismal despite the availability of targeted therapies and allogeneic stem cell transplantation (allo-SCT). Increasing the antileukemic efficacy of the pretransplant conditioning regimen may be a strategy to increase remission rates and duration. We therefore investigated the antiproliferative effects of nilotinib in combination with drugs that are usually used for conditioning: the alkylating agents mafosfamide, treosulfan, and busulfan. Drug combinations were tested in vitro in different imatinib-sensitive and imatinib-resistant BCR-ABL-positive cell lines. A tetrazolium-based MTT assay was used for the assessment and quantification of growth inhibition after exposure to alkylating agents alone or to combinations with nilotinib. Drug interaction was analyzed using the median-effect method of Chou and Talalay, and combination index (CI) values were calculated according to the classic isobologram equation. Treatment of imatinib-sensitive, BCR-ABL-positive K562 and LAMA84 cells with nilotinib in combination with mafosfamide, treosulfan, or busulfan resulted in synergistic (CI < 1), additive (CI ~ 1), and predominantly antagonistic (CI > 1) effects, respectively. In imatinib-resistant K562-R and LAMA84-R cells, all applied drug combinations were synergistic (CI < 1) at higher growth inhibition levels. Our in vitro data warrant further investigation and may provide the basis for nilotinib-supplemented conditioning regimens for allo-SCT in advanced-phase CML.

Induction of Erythroid Differentiation in Human Erythroleukemia Cells by Depletion of Malic Enzyme 2

PubMed Central

Everett, Peter; Clish, Clary B.; Sukhatme, Vikas P.

2010-01-01

Malic enzyme 2 (ME2) is a mitochondrial enzyme that catalyzes the conversion of malate to pyruvate and CO2 and uses NAD as a cofactor. Higher expression of this enzyme correlates with the degree of cell de-differentiation. We found that ME2 is expressed in K562 erythroleukemia cells, in which a number of agents have been found to induce differentiation either along the erythroid or the myeloid lineage. We found that knockdown of ME2 led to diminished proliferation of tumor cells and increased apoptosis in vitro. These findings were accompanied by differentiation of K562 cells along the erythroid lineage, as confirmed by staining for glycophorin A and hemoglobin production. ME2 knockdown also totally abolished growth of K562 cells in nude mice. Increased ROS levels, likely reflecting increased mitochondrial production, and a decreased NADPH/NADP+ ratio were noted but use of a free radical scavenger to decrease inhibition of ROS levels did not reverse the differentiation or apoptotic phenotype, suggesting that ROS production is not causally involved in the resultant phenotype. As might be expected, depletion of ME2 induced an increase in the NAD+/NADH ratio and ATP levels fell significantly. Inhibition of the malate-aspartate shuttle was insufficient to induce K562 differentiation. We also examined several intracellular signaling pathways and expression of transcription factors and intermediate filament proteins whose expression is known to be modulated during erythroid differentiation in K562 cells. We found that silencing of ME2 leads to phospho-ERK1/2 inhibition, phospho-AKT activation, increased GATA-1 expression and diminished vimentin expression. Metabolomic analysis, conducted to gain insight into intermediary metabolic pathways that ME2 knockdown might affect, showed that ME2 depletion resulted in high orotate levels, suggesting potential impairment of pyrimidine metabolism. Collectively our data point to ME2 as a potentially novel metabolic target for

Ester of Quinoxaline-7-carboxylate 1,4-di-N-oxide as Apoptosis Inductors in K-562 Cell Line: An in vitro, QSAR and DFT Study.

PubMed

Rivera, Gildardo; Andrade-Ochoa, Sergio; Romero, Manolo S Ortega; Palos, Isidro; Monge, Antonio; Sanchez-Torres, Luvia Enid

2017-01-01

Quinoxalines have shown a wide variety of biological activities including as antitumor agents. The aims of this study were to evaluate the activity of quinoxaline 1,4-di-N-oxide derivatives on K562 cells, the establishment of the mechanism of induced cell death, and the construction of predictive QSAR models. Sixteen esters of quinoxaline-7-carboxylate 1,4-di-N-oxide were evaluated for antitumor activity on K562 chronic myelogenous leukemia cells and their IC50 values were determined. The mechanism of induced cell death by the most active molecule was assessed by flow cytometry and an in silico study was conducted to optimize and calculate theoretical descriptors of all quinoxaline 1,4-di-N-oxide derivatives. QSAR and QPAR models were created using genetic algorithms. Our results show that compounds C5, C7, C10, C12 and C15 had the lowest IC50 of the series. C15 was the most active compound (IC50= 3.02 μg/mL), inducing caspase-dependent apoptotic cell death via the intrinsic pathway. QSAR and QPAR studies are discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Increased peroxisome proliferator-activated receptor γ activity reduces imatinib uptake and efficacy in chronic myeloid leukemia mononuclear cells

PubMed Central

Wang, Jueqiong; Lu, Liu; Kok, Chung H.; Saunders, Verity A.; Goyne, Jarrad M.; Dang, Phuong; Leclercq, Tamara M.; Hughes, Timothy P.; White, Deborah L.

2017-01-01

Imatinib is actively transported by organic cation transporter-1 (OCT-1) influx transporter, and low OCT-1 activity in diagnostic chronic myeloid leukemia blood mononuclear cells is significantly associated with poor molecular response to imatinib. Herein we report that, in diagnostic chronic myeloid leukemia mononuclear cells and BCR-ABL1+ cell lines, peroxisome proliferator-activated receptor γ agonists (GW1929, rosiglitazone, pioglitazone) significantly decrease OCT-1 activity; conversely, peroxisome proliferator-activated receptor γ antagonists (GW9662, T0070907) increase OCT-1 activity. Importantly, these effects can lead to corresponding changes in sensitivity to BCR-ABL kinase inhibition. Results were confirmed in peroxisome proliferator-activated receptor γ-transduced K562 cells. Furthermore, we identified a strong negative correlation between OCT-1 activity and peroxisome proliferator-activated receptor γ transcriptional activity in diagnostic chronic myeloid leukemia patients (n=84; P<0.0001), suggesting that peroxisome proliferator-activated receptor γ activation has a negative impact on the intracellular uptake of imatinib and consequent BCR-ABL kinase inhibition. The inter-patient variability of peroxisome proliferator-activated receptor γ activation likely accounts for the heterogeneity observed in patient OCT-1 activity at diagnosis. Recently, the peroxisome proliferator-activated receptor γ agonist pioglitazone was reported to act synergistically with imatinib, targeting the residual chronic myeloid leukemia stem cell pool. Our findings suggest that peroxisome proliferator-activated receptor γ ligands have differential effects on circulating mononuclear cells compared to stem cells. Since the effect of peroxisome proliferator-activated receptor γ activation on imatinib uptake in mononuclear cells may counteract the clinical benefit of this activation in stem cells, caution should be applied when combining these therapies, especially in

16 CFR 5.62 - Hearing rights of respondent.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Hearing rights of respondent. 5.62 Section 5.62 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE STANDARDS OF CONDUCT Disciplinary Actions Concerning Postemployment Conflict of Interest § 5.62 Hearing...

DNA methylation and targeted sequencing of methyltransferases family genes in canine acute myeloid leukaemia, modelling human myeloid leukaemia.

PubMed

Bronzini, I; Aresu, L; Paganin, M; Marchioretto, L; Comazzi, S; Cian, F; Riondato, F; Marconato, L; Martini, V; Te Kronnie, G

2017-09-01

Tumours shows aberrant DNA methylation patterns, being hypermethylated or hypomethylated compared with normal tissues. In human acute myeloid leukaemia (hAML) mutations in DNA methyltransferase (DNMT3A) are associated to a more aggressive tumour behaviour. As AML is lethal in dogs, we defined global DNA methylation content, and screened the C-terminal domain of DNMT3 family of genes for sequence variants in 39 canine acute myeloid leukaemia (cAML) cases. A heterogeneous pattern of DNA methylation was found among cAML samples, with subsets of cases being hypermethylated or hypomethylated compared with healthy controls; four recurrent single nucleotide variations (SNVs) were found in DNMT3L gene. Although SNVs were not directly correlated to whole genome DNA methylation levels, all hypomethylated cAML cases were homozygous for the deleterious mutation at p.Arg222Trp. This study contributes to understand genetic modifications of cAML, leading up to studies that will elucidate the role of methylome alterations in the pathogenesis of AML in dogs. © 2016 John Wiley & Sons Ltd.

What happened to anti-CD33 therapy for acute myeloid leukemia?

PubMed

Jurcic, Joseph G

2012-03-01

CD33, a 67-kDa glycoprotein expressed on the majority of myeloid leukemia cells as well as on normal myeloid and monocytic precursors, has been an attractive target for monoclonal antibody (mAb)-based therapy of acute myeloid leukemia (AML). Lintuzumab, an unconjugated, humanized anti-CD33 mAb, has modest single-agent activity against AML but failed to improve patient outcomes in two randomized trials when combined with conventional chemotherapy. Gemtuzumab ozogamicin, an anti-CD33 mAb conjugated to the antitumor antibiotic calicheamicin, improved survival in a subset of AML patients when combined with standard chemotherapy, but safety concerns led to US marketing withdrawal. The activity of these agents confirms that CD33 remains a viable therapeutic target for AML. Strategies to improve the results of mAb-based therapies for AML include antibody engineering to enhance effector function, use of alternative drugs and chemical linkers to develop safer and more effective drug conjugates, and radioimmunotherapeutic approaches.

Conservation of myeloid surface antigens on primate granulocytes.

PubMed

Letvin, N L; Todd, R F; Palley, L S; Schlossman, S F; Griffin, J D

1983-02-01

Monoclonal antibodies reactive with myeloid cell surface antigens were used to study evolutionary changes in granulocyte surface antigens from primate species. Certain of these granulocyte membrane antigens are conserved in phylogenetically distant species, indicating the potential functional importance of these structures. The degree of conservation of these antigens reflects the phylogenetic relationship between primate species. Furthermore, species of the same genus show similar patterns of binding to this panel of anti-human myeloid antibodies. This finding of conserved granulocyte surface antigens suggests that non-human primates may provide a model system for exploring uses of monoclonal antibodies in the treatment of human myeloid disorders.

Cutaneous myeloid sarcoma associated with chronic myeloid leukemia*

PubMed Central

Vasconcelos, Erica Rodrigues de Araujo; Bauk, Alexander Richard; Rochael, Mayra Carrijo

2017-01-01

Myeloid sarcoma is an extramedullary tumor of malignant myeloid cells often associated with acute myeloid leukemia, chronic myeloproliferative disorders and myelodysplastic syndromes. The skin is one of the most commonly affected sites. We report a rare case of cutaneous myeloid sarcoma associated with chronic myeloid leukemia. PMID:29267445

Myeloid leukemia factor

PubMed Central

Gobert, Vanessa; Haenlin, Marc; Waltzer, Lucas

2012-01-01

Even though deregulation of human MLF1, the founding member of the Myeloid Leukemia Factor family, has been associated with acute myeloid leukemia, the function and mode of action of this family of genes have remained rather mysterious. Yet, recent findings in Drosophila shed new light on their biological activity and suggest that they play an important role in hematopoiesis and leukemia, notably by regulating the stability of RUNX transcription factors, another family of conserved proteins with prominent roles in normal and malignant blood cell development. PMID:22885977

46 CFR 154.562 - Cargo hose: Hydrostatic test.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Hose § 154.562 Cargo hose: Hydrostatic test. Each cargo hose must pass a hydrostatic pressure test at ambient temperature of at least one and a half times its specified maximum working pressure but not more... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo hose: Hydrostatic test. 154.562 Section 154.562...

The T-Cell Oncogene Tal2 Is a Target of PU.1 and Upregulated during Osteoclastogenesis

PubMed Central

Courtial, Nadine; Mücke, Christian; Herkt, Stefanie; Kolodziej, Stephan; Hussong, Helge; Lausen, Jörn

2013-01-01

Transcription factors play a crucial role in regulating differentiation processes during human life and are important in disease. The basic helix-loop-helix transcription factors Tal1 and Lyl1 play a major role in the regulation of gene expression in the hematopoietic system and are involved in human leukemia. Tal2, which belongs to the same family of transcription factors as Tal1 and Lyl1, is also involved in human leukaemia. However, little is known regarding the expression and regulation of Tal2 in hematopoietic cells. Here we show that Tal2 is expressed in hematopoietic cells of the myeloid lineage. Interestingly, we found that usage of the Tal2 promoter is different in human and mouse cells. Two promoters, hP1 and hP2 drive Tal2 expression in human erythroleukemia K562 cells, however in mouse RAW cells only the mP1 promoter is used. Furthermore, we found that Tal2 expression is upregulated during oesteoclastogenesis. We show that Tal2 is a direct target gene of the myeloid transcription factor PU.1, which is a key transcription factor for osteoclast gene expression. Strikingly, PU.1 binding to the P1 promoter is conserved between mouse and human, but PU.1 binding to P2 was only detected in human K562 cells. Additionally, we provide evidence that Tal2 influences the expression of the osteoclastic differentiation gene TRACP. These findings provide novel insight into the expression control of Tal2 in hematopoietic cells and reveal a function of Tal2 as a regulator of gene expression during osteoclast differentiation. PMID:24086757

A nanocomplex of Cu(II) with theophylline drug; synthesis, characterization, and anticancer activity against K562 cell line

NASA Astrophysics Data System (ADS)

Sahlabadi, Maryam; Daryanavard, Marzieh; Hadadzadeh, Hassan; Amirghofran, Zahra

2018-03-01

A new mononuclear of copper (II), [Cu(theophylline)2(H2O)3]·2H2O, has been synthesized by reaction of theophylline (1,3-dimethyl-7H-purine-2,6-dione) with copper (II) nitrate in water. Further, its nanocomplex has been prepared through the three different methods including sonication, grinding, and a combination thereof, sonication-grinding. The prepared nanocomplex was characterized using different techniques including FT-IR, UV-Vis, X-ray diffraction (XRD) analysis, and field-emission scanning electron microscopy (FE-SEM). Moreover, the anticancer activity of the precursor complex, nanocomplex, free theophylline ligand, and the starting copper salt (Cu(NO3)2·3H2O) was investigated against the K562 cell line. The results show that the nanocomplex is an effective nano metal-based anticancer agent with IC50 = 11.7 μM.

Presence of estrogen receptors in human myeloid monocytic cells (THP-1 cell line).

PubMed

Cutolo, M; Villaggio, B; Bisso, A; Sulli, A; Coviello, D; Dayer, J M

2001-01-01

To test THP-1 cells for the presence of estrogen receptors (ER) since studies have demonstrated in vivo and in vitro, the influence of estrogens on cells involved in immune response (i.e. macrophages), and since it has been demonstrated that human myeloid monocytic THP-1 cells acquire phenotypic and functional macrophage-like features after incubation with several cytokines or pharmacological agents. Stimulation of THP-1 cells with phorbol myristate acetate (PMA) to prompt their differentiation into macrophage-like cells and evaluation of the possible induction of ER. The expression of ER was analyzed by immunocytochemical assay, reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot analysis. After stimulation by PMA, the human myeloid monocytic THP-1 cells showed the presence of ER, together with markers of monocytic cell differentiation such as CD68, CD54 and HLA-DR. Estrogen effects may be exerted directly through ER on monocytes/macrophages. PMA-treated THP-1 cells may constitute a useful in vitro model to determine the effects of estrogens on macrophage-like cells and their implications in the inflammatory and immune processes.

31 CFR 562.307 - Property; property interest.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Property; property interest. 562.307 Section 562.307 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE..., or interest or interests therein, present, future, or contingent. ...

31 CFR 562.307 - Property; property interest.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Property; property interest. 562.307 Section 562.307 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE..., or interest or interests therein, present, future, or contingent. ...

31 CFR 562.307 - Property; property interest.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Property; property interest. 562.307 Section 562.307 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE..., or interest or interests therein, present, future, or contingent. ...

31 CFR 562.307 - Property; property interest.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Property; property interest. 562.307 Section 562.307 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE..., or interest or interests therein, present, future, or contingent. ...

Use of deferasirox, an iron chelator, to overcome imatinib resistance of chronic myeloid leukemia cells.

PubMed

Kim, Dae Sik; Na, Yoo Jin; Kang, Myoung Hee; Yoon, Soo-Young; Choi, Chul Won

2016-03-01

The treatment of chronic myeloid leukemia (CML) has achieved impressive success since the development of the Bcr-Abl tyrosine kinase inhibitor, imatinib mesylate. Nevertheless, resistance to imatinib has been observed, and a substantial number of patients need alternative treatment strategies. We have evaluated the effects of deferasirox, an orally active iron chelator, and imatinib on K562 and KU812 human CML cell lines. Imatinib-resistant CML cell lines were created by exposing cells to gradually increasing concentrations of imatinib. Co-treatment of cells with deferasirox and imatinib induced a synergistic dose-dependent inhibition of proliferation of both CML cell lines. Cell cycle analysis showed an accumulation of cells in the subG1 phase. Western blot analysis of apoptotic proteins showed that co-treatment with deferasirox and imatinib induced an increased expression of apoptotic proteins. These tendencies were clearly identified in imatinib-resistant CML cell lines. The results also showed that co-treatment with deferasirox and imatinib reduced the expression of BcrAbl, phosphorylated Bcr-Abl, nuclear factor-κB (NF-κB) and β-catenin. We observed synergistic effects of deferasirox and imatinib on both imatinib-resistant and imatinib-sensitive cell lines. These effects were due to induction of apoptosis and cell cycle arrest by down-regulated expression of NF-κB and β-catenin levels. Based on these results, we suggest that a combination treatment of deferasirox and imatinib could be considered as an alternative treatment option for imatinib-resistant CML.

Thrombopoietin/MPL participates in initiating and maintaining RUNX1-ETO acute myeloid leukemia via PI3K/AKT signaling

PubMed Central

Pulikkan, John Anto; Madera, Dmitri; Xue, Liting; Bradley, Paul; Landrette, Sean Francis; Kuo, Ya-Huei; Abbas, Saman; Zhu, Lihua Julie; Valk, Peter

2012-01-01

Oncogenic mutations in components of cytokine signaling pathways elicit ligand-independent activation of downstream signaling, enhancing proliferation and survival in acute myeloid leukemia (AML). The myeloproliferative leukemia virus oncogene, MPL, a homodimeric receptor activated by thrombopoietin (THPO), is mutated in myeloproliferative disorders but rarely in AML. Here we show that wild-type MPL expression is increased in a fraction of human AML samples expressing RUNX1-ETO, a fusion protein created by chromosome translocation t(8;21), and that up-regulation of Mpl expression in mice induces AML when coexpressed with RUNX1-ETO. The leukemic cells are sensitive to THPO, activating survival and proliferative responses. Mpl expression is not regulated by RUNX1-ETO in mouse hematopoietic progenitors or leukemic cells. Moreover, we find that activation of PI3K/AKT but not ERK/MEK pathway is a critical mediator of the MPL-directed antiapoptotic function in leukemic cells. Hence, this study provides evidence that up-regulation of wild-type MPL levels promotes leukemia development and maintenance through activation of the PI3K/AKT axis, and suggests that inhibitors of this axis could be effective for treatment of MPL-positive AML. PMID:22613795

Thrombopoietin/MPL participates in initiating and maintaining RUNX1-ETO acute myeloid leukemia via PI3K/AKT signaling.

PubMed

Pulikkan, John Anto; Madera, Dmitri; Xue, Liting; Bradley, Paul; Landrette, Sean Francis; Kuo, Ya-Huei; Abbas, Saman; Zhu, Lihua Julie; Valk, Peter; Castilla, Lucio Hernán

2012-07-26

Oncogenic mutations in components of cytokine signaling pathways elicit ligand-independent activation of downstream signaling, enhancing proliferation and survival in acute myeloid leukemia (AML). The myeloproliferative leukemia virus oncogene, MPL, a homodimeric receptor activated by thrombopoietin (THPO), is mutated in myeloproliferative disorders but rarely in AML. Here we show that wild-type MPL expression is increased in a fraction of human AML samples expressing RUNX1-ETO, a fusion protein created by chromosome translocation t(8;21), and that up-regulation of Mpl expression in mice induces AML when coexpressed with RUNX1-ETO. The leukemic cells are sensitive to THPO, activating survival and proliferative responses. Mpl expression is not regulated by RUNX1-ETO in mouse hematopoietic progenitors or leukemic cells. Moreover, we find that activation of PI3K/AKT but not ERK/MEK pathway is a critical mediator of the MPL-directed antiapoptotic function in leukemic cells. Hence, this study provides evidence that up-regulation of wild-type MPL levels promotes leukemia development and maintenance through activation of the PI3K/AKT axis, and suggests that inhibitors of this axis could be effective for treatment of MPL-positive AML.

33 CFR 183.562 - Metallic fuel lines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Metallic fuel lines. 183.562...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Manufacturer Requirements § 183.562 Metallic fuel lines. (a) Each metallic fuel line that is mounted to the boat structure must be connected to the...

Polymorphonuclear neutrophils and granulocytic myeloid-derived suppressor cells inhibit natural killer cell activity toward Aspergillus fumigatus.

PubMed

Mueller-Leisse, Johanna; Brueggemann, Sabrina; Bouzani, Maria; Schmitt, Anna-Lena; Einsele, Hermann; Loeffler, Juergen

2015-08-01

Invasive aspergillosis is a devastating infectious disease in immunocompromised patients. Besides neutrophils and macrophages, natural killer (NK) cells have recently emerged as important players in immunity to this infection. It was shown that NK cells comprise an essential role in the clearance of Aspergillus fumigatus (A. fumigatus) in neutropenic but not in nonneutropenic mice. However, the antifungal activity of NK cells and their regulation have not been fully characterized. In this study, we investigated the interplay between polymorphonuclear neutrophils (PMNs) or granulocyte myeloid-derived suppressor cells (Gr-MDSCs) with NK cells. Both cell types exhibited an equal inhibitory effect on NK cell activation through downregulation of NKp30 expression on the cell surface and cytotoxicity towards the cell line K562. Furthermore, we showed that NK cell activation and antifungal cytotoxicity were impaired when NK cells had been cultured in the presence of PMNs or Gr-MDSCs before fungal stimulation. Besides the reduced cytotoxicity a decreased release of interferon gamma (IFNγ), a key player in the clearance of an A. fumigatus infection, was observed. Thus, inhibition of NK cell activity by PMNs or Gr-MDSCs might impair an effective anti-fungal immune response during recovery from conditions such as hematopoietic stem cell transplantation. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A proteomic chronology of gene expression through the cell cycle in human myeloid leukemia cells.

PubMed

Ly, Tony; Ahmad, Yasmeen; Shlien, Adam; Soroka, Dominique; Mills, Allie; Emanuele, Michael J; Stratton, Michael R; Lamond, Angus I

2014-01-01

Technological advances have enabled the analysis of cellular protein and RNA levels with unprecedented depth and sensitivity, allowing for an unbiased re-evaluation of gene regulation during fundamental biological processes. Here, we have chronicled the dynamics of protein and mRNA expression levels across a minimally perturbed cell cycle in human myeloid leukemia cells using centrifugal elutriation combined with mass spectrometry-based proteomics and RNA-Seq, avoiding artificial synchronization procedures. We identify myeloid-specific gene expression and variations in protein abundance, isoform expression and phosphorylation at different cell cycle stages. We dissect the relationship between protein and mRNA levels for both bulk gene expression and for over ∼6000 genes individually across the cell cycle, revealing complex, gene-specific patterns. This data set, one of the deepest surveys to date of gene expression in human cells, is presented in an online, searchable database, the Encyclopedia of Proteome Dynamics (http://www.peptracker.com/epd/). DOI: http://dx.doi.org/10.7554/eLife.01630.001.

A proteomic chronology of gene expression through the cell cycle in human myeloid leukemia cells

PubMed Central

Ly, Tony; Ahmad, Yasmeen; Shlien, Adam; Soroka, Dominique; Mills, Allie; Emanuele, Michael J; Stratton, Michael R; Lamond, Angus I

2014-01-01

Technological advances have enabled the analysis of cellular protein and RNA levels with unprecedented depth and sensitivity, allowing for an unbiased re-evaluation of gene regulation during fundamental biological processes. Here, we have chronicled the dynamics of protein and mRNA expression levels across a minimally perturbed cell cycle in human myeloid leukemia cells using centrifugal elutriation combined with mass spectrometry-based proteomics and RNA-Seq, avoiding artificial synchronization procedures. We identify myeloid-specific gene expression and variations in protein abundance, isoform expression and phosphorylation at different cell cycle stages. We dissect the relationship between protein and mRNA levels for both bulk gene expression and for over ∼6000 genes individually across the cell cycle, revealing complex, gene-specific patterns. This data set, one of the deepest surveys to date of gene expression in human cells, is presented in an online, searchable database, the Encyclopedia of Proteome Dynamics (http://www.peptracker.com/epd/). DOI: http://dx.doi.org/10.7554/eLife.01630.001 PMID:24596151

Musashi-2 regulates normal hematopoiesis and promotes aggressive myeloid leukemia

PubMed Central

Kharas, Michael G; Lengner, Christopher J; Al-Shahrour, Fatima; Bullinger, Lars; Ball, Brian; Zaidi, Samir; Morgan, Kelly; Tam, Winnie; Paktinat, Mahnaz; Okabe, Rachel; Gozo, Maricel; Einhorn, William; Lane, Steven W; Scholl, Claudia; Fröhling, Stefan; Fleming, Mark; Ebert, Benjamin L; Gilliland, D Gary; Jaenisch, Rudolf; Daley, George Q

2011-01-01

RNA-binding proteins of the Musashi (Msi) family are expressed in stem cell compartments and in aggressive tumors, but they have not yet been widely explored in the blood. Here we demonstrate that Msi2 is the predominant form expressed in hematopoietic stem cells (HSCs), and its knockdown leads to reduced engraftment and depletion of HSCs in vivo. Overexpression of human MSI2 in a mouse model increases HSC cell cycle progression and cooperates with the chronic myeloid leukemia–associated BCR-ABL1 oncoprotein to induce an aggressive leukemia. MSI2 is overexpressed in human myeloid leukemia cell lines, and its depletion leads to decreased proliferation and increased apoptosis. Expression levels in human myeloid leukemia directly correlate with decreased survival in patients with the disease, thereby defining MSI2 expression as a new prognostic marker and as a new target for therapy in acute myeloid leukemia (AML). PMID:20616797

The Recognition of N-Glycans by the Lectin ArtinM Mediates Cell Death of a Human Myeloid Leukemia Cell Line

PubMed Central

Carvalho, Fernanda Caroline; Soares, Sandro Gomes; Tamarozzi, Mirela Barros; Rego, Eduardo Magalhães; Roque-Barreira, Maria-Cristina

2011-01-01

ArtinM, a d-mannose-binding lectin from Artocarpus heterophyllus (jackfruit), interacts with N-glycosylated receptors on the surface of several cells of hematopoietic origin, triggering cell migration, degranulation, and cytokine release. Because malignant transformation is often associated with altered expression of cell surface glycans, we evaluated the interaction of ArtinM with human myelocytic leukemia cells and investigated cellular responses to lectin binding. The intensity of ArtinM binding varied across 3 leukemia cell lines: NB4>K562>U937. The binding, which was directly related to cell growth suppression, was inhibited in the presence of Manα1-3(Manα1-6)Manβ1, and was reverted in underglycosylated NB4 cells. ArtinM interaction with NB4 cells induced cell death (IC50 = 10 µg/mL), as indicated by cell surface exposure of phosphatidylserine and disruption of mitochondrial membrane potential unassociated with caspase activation or DNA fragmentation. Moreover, ArtinM treatment of NB4 cells strongly induced reactive oxygen species generation and autophagy, as indicated by the detection of acidic vesicular organelles in the treated cells. NB4 cell death was attributed to ArtinM recognition of the trimannosyl core of N-glycans containing a ß1,6-GlcNAc branch linked to α1,6-mannose. This modification correlated with higher levels of N-acetylglucosaminyltransferase V transcripts in NB4 cells than in K562 or U937 cells. Our results provide new insights into the potential of N-glycans containing a β1,6-GlcNAc branch linked to α1,6-mannose as a novel target for anti-leukemia treatment. PMID:22132163

Preparation of isolated nuclei from K 562 haemopoietic cell line for high resolution scanning electron microscopy.

PubMed

Reipert, S; Reipert, B M; Allen, T D

1994-09-01

The aim of the work is to visualise nuclear pore complexes (NPCs) in mammalian cells by high resolution scanning electron microscopy. A detergent-free isolation protocol was employed to obtain clean nuclei from the haemopoietic cell line K 562. Nuclear isolation was performed by mechanical homogenisation under hypotonic conditions followed by purification of the nuclear fraction. The isolated nuclei were attached to silicon chips, fixed, critical point dried, and sputter coated with a thin film (3-4 nm) of tantalum. Analysis of the nuclear surface by scanning electron microscopy (SEM) revealed a strong sensitivity of the outer nuclear membrane (ONM) to disruption during the isolation procedure. A significant reduction of the characteristic pattern of damage to the ONM was achieved by means of an isopicnic centrifugation on an isoosmolar balanced Percoll gradient. Analysis of the population of isolated nuclei by flow cytometry showed no signs of cell cycle specific losses of nuclei during isolation. The SEM investigations of the morphology of the nuclear envelope (NE) and of substructural details of NPCs and polyribosomes were performed using an in-lens field emission scanning electron microscope.

Co-culture of stromal and erythroleukemia cells in a perfused hollow fiber bioreactor system as an in vitro bone marrow model for myeloid leukemia.

PubMed

Usuludin, Suaidah Binte Mohamed; Cao, Xue; Lim, Mayasari

2012-05-01

We have developed a hematopoietic co-culture system using the hollow fiber bioreactor (HFBR) as a potential in vitro bone marrow model for evaluating leukemia. Supporting stroma using HS-5 cells was established in HFBR system and the current bioprocess configuration yielded an average glucose consumption of 640 mg/day and an average protein concentration of 6.40 mg/mL in the extracapillary space over 28 days. Co-culture with erythroleukemia K562 cells was used as a model for myelo-leukemic cell proliferation and differentiation. Two distinct localizations of K562 cells (loosely adhered and adherent cells) were identified and characterized after 2 weeks. The HFBR co-culture resulted in greater leukemic cell expansion (3,130 fold vs. 43 fold) compared to a standard tissue culture polystyrene (TCP) culture. Majority of expanded cells (68%) in HFBR culture were the adherent population, highlighting the importance of cell-cell contact for myelo-leukemic proliferation. Differentiation tendencies in TCP favored maturation toward monocyte and erythrocyte lineages but maintained a pool of myeloid progenitors. In contrast, HFBR co-culture exhibited greater lineage diversity, stimulating monocytic and megakaryocytic differentiation while inhibiting erythroid maturation. With the extensive stromal expansion capacity on hollow fiber surfaces, the HFBR system is able to achieve high cell densities and 3D cell-cell contacts mimicking the bone marrow microenvironment. The proposed in vitro system represents a dynamic and highly scalable 3D co-culture platform for the study of cell-stroma dependent hematopoietic/leukemic cell functions and ex vivo expansion. Copyright © 2011 Wiley Periodicals, Inc.

DNA Methylation as an Epigenetic Factor in the Development and Progression of Polycythemia Vera

DTIC Science & Technology

2008-10-01

vera and idiopathic myelofibrosis. Pathol Biol ( Paris ). 2001;49:164-166. 2. Spivak JL. Diagnosis of the myeloproliferative disorders: resolving...leukemia cell lines with different cellular origin (myeloid cell lines KG1, KG1a, HEL, K562, and TF1; T lymphoid cell lines CEM and JTAg; and B lymphoid...in the cell lines of lymphoid origin versus myeloid leukemia cell lines and a GM-CSF- Services Email this article to a friend Download to

Superparamagnetic poly(methyl methacrylate) nanoparticles surface modified with folic acid presenting cell uptake mediated by endocytosis

NASA Astrophysics Data System (ADS)

Feuser, Paulo Emilio; Jacques, Amanda Virtuoso; Arévalo, Juan Marcelo Carpio; Rocha, Maria Eliane Merlin; dos Santos-Silva, Maria Claudia; Sayer, Claudia; de Araújo, Pedro H. Hermes

2016-04-01

The encapsulation of superparamagnetic nanoparticles (MNPs) in polymeric nanoparticles (NPs) with modified surfaces can improve targeted delivery and induce cell death by hyperthermia. The goals of this study were to synthesize and characterize surface modified superparamagnetic poly(methyl methacrylate) with folic acid (FA) prepared by miniemulsion polymerization (MNPsPMMA-FA) and to evaluate their in vitro cytotoxicity and cellular uptake in non-tumor cells, murine fibroblast (L929) cells and tumor cells that overexpressed folate receptor (FR) β, and chronic myeloid leukemia cells in blast crisis (K562). Lastly, hemolysis assays were performed on human red blood cells. MNPsPMMA-FA presented an average mean diameter of 135 nm and a saturation magnetization (Ms) value of 37 emu/g of iron oxide, as well as superparamagnetic behavior. The MNPsPMMA-FA did not present cytotoxicity in L929 and K562 cells. Cellular uptake assays showed a higher uptake of MNPsPMMA-FA than MNPsPMMA in K562 cells when incubated at 37 °C. On the other hand, MNPsPMMA-FA showed a low uptake when endocytosis mechanisms were blocked at low temperature (4 °C), suggesting that the MNPsPMMA-FA uptake was mediated by endocytosis. High concentrations of MNPsPMMA-FA showed hemocompatibility when incubated for 24 h in human red blood cells. Therefore, our results suggest that these carrier systems can be an excellent alternative in targeted drug delivery via FR.

31 CFR 562.310 - U.S. financial institution.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false U.S. financial institution. 562.310 Section 562.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... foreign exchange, securities, commodity futures or options, or procuring purchasers and sellers thereof...

31 CFR 562.310 - U.S. financial institution.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false U.S. financial institution. 562.310 Section 562.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... foreign exchange, securities, commodity futures or options, or procuring purchasers and sellers thereof...

31 CFR 562.310 - U.S. financial institution.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false U.S. financial institution. 562.310 Section 562.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... foreign exchange, securities, commodity futures or options, or procuring purchasers and sellers thereof...

31 CFR 562.310 - U.S. financial institution.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false U.S. financial institution. 562.310 Section 562.310 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE... foreign exchange, securities, commodity futures or options, or procuring purchasers and sellers thereof...

Use of deferasirox, an iron chelator, to overcome imatinib resistance of chronic myeloid leukemia cells

PubMed Central

Kim, Dae Sik; Na, Yoo Jin; Kang, Myoung Hee; Yoon, Soo-Young; Choi, Chul Won

2016-01-01

Background/Aims: The treatment of chronic myeloid leukemia (CML) has achieved impressive success since the development of the Bcr-Abl tyrosine kinase inhibitor, imatinib mesylate. Nevertheless, resistance to imatinib has been observed, and a substantial number of patients need alternative treatment strategies. Methods: We have evaluated the effects of deferasirox, an orally active iron chelator, and imatinib on K562 and KU812 human CML cell lines. Imatinib-resistant CML cell lines were created by exposing cells to gradually increasing concentrations of imatinib. Results: Co-treatment of cells with deferasirox and imatinib induced a synergistic dose-dependent inhibition of proliferation of both CML cell lines. Cell cycle analysis showed an accumulation of cells in the subG1 phase. Western blot analysis of apoptotic proteins showed that co-treatment with deferasirox and imatinib induced an increased expression of apoptotic proteins. These tendencies were clearly identified in imatinib-resistant CML cell lines. The results also showed that co-treatment with deferasirox and imatinib reduced the expression of BcrAbl, phosphorylated Bcr-Abl, nuclear factor-κB (NF-κB) and β-catenin. Conclusions: We observed synergistic effects of deferasirox and imatinib on both imatinib-resistant and imatinib-sensitive cell lines. These effects were due to induction of apoptosis and cell cycle arrest by down-regulated expression of NF-κB and β-catenin levels. Based on these results, we suggest that a combination treatment of deferasirox and imatinib could be considered as an alternative treatment option for imatinib-resistant CML. PMID:26874514

Myeloid cell origins, differentiation, and clinical implications

PubMed Central

Weiskopf, Kipp; Schnorr, Peter J.; Pang, Wendy W.; Chao, Mark P.; Chhabra, Akanksha; Seita, Jun; Feng, Mingye; Weissman, Irving L.

2016-01-01

The hematopoietic stem cell (HSC) is a multipotent stem cell that resides in the bone marrow and has the ability to form all of the cells of the blood and immune system. Since its first purification in 1988, additional studies have refined the phenotype and functionality of HSCs and characterized all of their downstream progeny. The hematopoietic lineage is divided into two main branches: the myeloid and lymphoid arms. The myeloid arm is characterized by the Common Myeloid Progenitor and all of its resulting cell types. The stages of hematopoiesis have been defined in both mice and humans. During embryological development, the earliest hematopoiesis takes place in yolk sac blood islands then migrates to the fetal liver and hematopoietic organs. Some adult myeloid populations develop directly from yolk sac progenitors without apparent bone marrow intermediates, such as tissue resident macrophages. Hematopoiesis also changes over time, with a bias of the dominating HSCs towards myeloid development as animals age. Defects in myelopoiesis contribute to many hematologic disorders, and some of these can be overcome with therapies that target the aberrant stage of development. Furthermore, insights into myeloid development have informed us of mechanisms of programmed cell removal. The CD47/SIRPα axis, a myeloid-specific immune checkpoint, limits macrophage removal of HSCs but can be exploited by hematologic and solid malignancies. Therapeutics targeting CD47 represent a new strategy for treating cancer. Overall, an understanding of hematopoiesis and myeloid cell development has implications for regenerative medicine, hematopoietic cell transplantation, malignancy, and many other diseases. PMID:27763252

Haemophilus ducreyi Partially Activates Human Myeloid Dendritic Cells▿

PubMed Central

Banks, Keith E.; Humphreys, Tricia L.; Li, Wei; Katz, Barry P.; Wilkes, David S.; Spinola, Stanley M.

2007-01-01

Dendritic cells (DC) orchestrate innate and adaptive immune responses to bacteria. How Haemophilus ducreyi, which causes genital ulcers and regional lymphadenitis, interacts with DC is unknown. H. ducreyi evades uptake by polymorphonuclear leukocyte and macrophage-like cell lines by secreting LspA1 and LspA2. Many H. ducreyi strains express cytolethal distending toxin (CDT), and recombinant CDT causes apoptosis of DC in vitro. Here, we examined interactions between DC and H. ducreyi 35000HP, which produces LspA1, LspA2, and CDT. In human volunteers infected with 35000HP, the ratio of myeloid DC to plasmacytoid DC was 2.8:1 in lesions, compared to a ratio of 1:1 in peripheral blood. Using myeloid DC derived from monocytes as surrogates for lesional DC, we found that DC infected with 35000HP remained as viable as uninfected DC for up to 48 h. Gentamicin protection and confocal microscopy assays demonstrated that DC ingested and killed 35000HP, but killing was incomplete at 48 h. The expression of LspA1 and LspA2 did not inhibit the uptake of H. ducreyi, despite inactivating Src kinases. Infection of DC with live 35000HP caused less cell surface marker activation than infection with heat-killed 35000HP and lipopolysaccharide (LPS) and inhibited maturation by LPS. However, infection of DC with live bacteria caused the secretion of significantly higher levels of interleukin-6 and tumor necrosis factor alpha than infection with heat-killed bacteria and LPS. The survival of H. ducreyi in DC may provide a mechanism by which the organism traffics to lymph nodes. Partial activation of DC may abrogate the establishment of a full Th1 response and an environment that promotes phagocytosis. PMID:17923525

Tumor SHB gene expression affects disease characteristics in human acute myeloid leukemia.

PubMed

Jamalpour, Maria; Li, Xiujuan; Cavelier, Lucia; Gustafsson, Karin; Mostoslavsky, Gustavo; Höglund, Martin; Welsh, Michael

2017-10-01

The mouse Shb gene coding for the Src Homology 2-domain containing adapter protein B has recently been placed in context of BCRABL1-induced myeloid leukemia in mice and the current study was performed in order to relate SHB to human acute myeloid leukemia (AML). Publicly available AML databases were mined for SHB gene expression and patient survival. SHB gene expression was determined in the Uppsala cohort of AML patients by qPCR. Cell proliferation was determined after SHB gene knockdown in leukemic cell lines. Despite a low frequency of SHB gene mutations, many tumors overexpressed SHB mRNA compared with normal myeloid blood cells. AML patients with tumors expressing low SHB mRNA displayed longer survival times. A subgroup of AML exhibiting a favorable prognosis, acute promyelocytic leukemia (APL) with a PMLRARA translocation, expressed less SHB mRNA than AML tumors in general. When examining genes co-expressed with SHB in AML tumors, four other genes ( PAX5, HDAC7, BCORL1, TET1) related to leukemia were identified. A network consisting of these genes plus SHB was identified that relates to certain phenotypic characteristics, such as immune cell, vascular and apoptotic features. SHB knockdown in the APL PMLRARA cell line NB4 and the monocyte/macrophage cell line MM6 adversely affected proliferation, linking SHB gene expression to tumor cell expansion and consequently to patient survival. It is concluded that tumor SHB gene expression relates to AML survival and its subgroup APL. Moreover, this gene is included in a network of genes that plays a role for an AML phenotype exhibiting certain immune cell, vascular and apoptotic characteristics.

Caffeine affects the biological responses of human hematopoietic cells of myeloid lineage via downregulation of the mTOR pathway and xanthine oxidase activity

PubMed Central

Abooali, Maryam; Yasinska, Inna M.; Casely-Hayford, Maxwell A.; Berger, Steffen M.; Fasler-Kan, Elizaveta; Sumbayev, Vadim V.

2015-01-01

Correction of human myeloid cell function is crucial for the prevention of inflammatory and allergic reactions as well as leukaemia progression. Caffeine, a naturally occurring food component, is known to display anti-inflammatory effects which have previously been ascribed largely to its inhibitory actions on phosphodiesterase. However, more recent studies suggest an additional role in affecting the activity of the mammalian target of rapamycin (mTOR), a master regulator of myeloid cell translational pathways, although detailed molecular events underlying its mode of action have not been elucidated. Here, we report the cellular uptake of caffeine, without metabolisation, by healthy and malignant hematopoietic myeloid cells including monocytes, basophils and primary acute myeloid leukaemia mononuclear blasts. Unmodified caffeine downregulated mTOR signalling, which affected glycolysis and the release of pro-inflammatory/pro-angiogenic cytokines as well as other inflammatory mediators. In monocytes, the effects of caffeine were potentiated by its ability to inhibit xanthine oxidase, an enzyme which plays a central role in human purine catabolism by generating uric acid. In basophils, caffeine also increased intracellular cyclic adenosine monophosphate (cAMP) levels which further enhanced its inhibitory action on mTOR. These results demonstrate an important mode of pharmacological action of caffeine with potentially wide-ranging therapeutic impact for treating non-infectious disorders of the human immune system, where it could be applied directly to inflammatory cells. PMID:26384306

Biology and relevance of human acute myeloid leukemia stem cells.

PubMed

Thomas, Daniel; Majeti, Ravindra

2017-03-23

Evidence of human acute myeloid leukemia stem cells (AML LSCs) was first reported nearly 2 decades ago through the identification of rare subpopulations of engrafting cells in xenotransplantation assays. These AML LSCs were shown to reside at the apex of a cellular hierarchy that initiates and maintains the disease, exhibiting properties of self-renewal, cell cycle quiescence, and chemoresistance. This cancer stem cell model offers an explanation for chemotherapy resistance and disease relapse and implies that approaches to treatment must eradicate LSCs for cure. More recently, a number of studies have both refined and expanded our understanding of LSCs and intrapatient heterogeneity in AML using improved xenotransplant models, genome-scale analyses, and experimental manipulation of primary patient cells. Here, we review these studies with a focus on the immunophenotype, biological properties, epigenetics, genetics, and clinical associations of human AML LSCs and discuss critical questions that need to be addressed in future research. © 2017 by The American Society of Hematology.

The effect of redox-related species of nitrogen monoxide on transferrin and iron uptake and cellular proliferation of erythroleukemia (K562) cells.

PubMed

Richardson, D R; Neumannova, V; Nagy, E; Ponka, P

1995-10-15

The iron-responsive element-binding protein (IRE-BP) modulates both ferritin mRNA translation and transferrin receptor (TfR) mRNA stability by binding to specific mRNA sequences called iron-responsive elements (IREs). The regulation of IRE-BP in situ could possibly occur either through its Fe-S cluster and/or via free cysteine sulphydryl groups such as cysteine 437 (Philpott et al, J Biol Chem 268:17655, 1993; and Hirling et al, EMBO J 13:453, 1994). Recently, nitrogen monoxide (NO) has been shown to have markedly different biologic effects depending on its redox state (Lipton et al, Nature 364:626, 1993). Considering this fact, it is conceivable that the NO group, as either the nitrosonium ion (NO+) or nitric oxide (NO+), may regulate IRE-BP activity by S-nitrosylation of key sulphydryl groups or via ligation of NO. to the Fe-S cluster, respectively. This hypothesis has been examined using the NO+ generator, sodium nitroprusside (SNP); the NO. generator, S-nitroso-N-acetylpenicillamine (SNAP); and the NO./peroxynitrite (ONOO-) generator, 3-morpholinosydnonimine hydrochloride (SIN-1). Treatment of K562 cells for 18 hours with SNP (1 mmol/L) resulted in a pronounced decrease in both the RNA-binding activity of IRE-BP and the level of TfR mRNA. In addition, Scatchard analysis showed a marked decrease in the number of specific Tf-binding sites, from 590,000/cell (control) to 170,000/cell (test), and there was also a distinct decrease in Fe uptake. Furthermore, SNP did not decrease cellular viability or proliferation. In contrast, the NO. generator, SNAP (1 mmol/L), increased RNA-binding activity of IRE-BP, the level of TfR mRNA, and the number of TfRs in K562 cells. Moreover, both SNAP (1 mmol/L) and SIN-1 (0.5 mmol/L) reduced cellular proliferation. The results are discussed in context of the possible physiologic role of redox-related species of NO in regulating iron metabolism.

Diterpenes from Xylopia langsdorffiana inhibit cell growth and induce differentiation in human leukemia cells.

PubMed

Castello Branco, Marianna V S; Anazetti, Maristella C; Silva, Marcelo S; Tavares, Josean F; Diniz, Margareth F F Melo; Frungillo, Lucas; Haun, Marcela; Melo, Patrícia S

2009-01-01

Two new diterpenes were isolated from stems and leaves of Xylopia langsdorffiana, ent-atisane-7alpha,16alpha-diol (xylodiol) and ent-7alpha-acetoxytrachyloban-18-oic acid (trachylobane), along with the known 8(17),12E,14-labdatrien-18-oic acid (labdane). We investigated their antitumour effects on HL60, U937 and K562 human leukemia cell lines. We found that xylodiol was the most potent diterpene in inhibiting cell proliferation of HL60, U937 and K562 cells, with mean IC50 values of 90, 80 and 50 microM, respectively. Based on the nitroblue tetrazolium (NBT) reduction assay, all the diterpenes were found to induce terminal differentiation in HL60 and K562 cells, with xylodiol being the most effective. NBT reduction was increased by almost 120% after 12 h exposure of HL60 cells to xylodiol at a concentration lower than the IC50 (50 microM). Thus, xylodiol inhibited human leukemia cell growth in vitro partly by inducing cell differentiation, and merits further studies to examine its mechanism of action as a potential antitumoural agent.

General Information about Childhood Acute Myeloid Leukemia and Other Myeloid Malignancies

MedlinePlus

... Other Myeloid Malignancies Treatment (PDQ®)–Patient Version General Information About Childhood Acute Myeloid Leukemia and Other Myeloid ... the PDQ Pediatric Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

ENL links histone acetylation to oncogenic gene expression in acute myeloid leukaemia.

PubMed

Wan, Liling; Wen, Hong; Li, Yuanyuan; Lyu, Jie; Xi, Yuanxin; Hoshii, Takayuki; Joseph, Julia K; Wang, Xiaolu; Loh, Yong-Hwee E; Erb, Michael A; Souza, Amanda L; Bradner, James E; Shen, Li; Li, Wei; Li, Haitao; Allis, C David; Armstrong, Scott A; Shi, Xiaobing

2017-03-09

Cancer cells are characterized by aberrant epigenetic landscapes and often exploit chromatin machinery to activate oncogenic gene expression programs. Recognition of modified histones by 'reader' proteins constitutes a key mechanism underlying these processes; therefore, targeting such pathways holds clinical promise, as exemplified by the development of bromodomain and extra-terminal (BET) inhibitors. We recently identified the YEATS domain as an acetyl-lysine-binding module, but its functional importance in human cancer remains unknown. Here we show that the YEATS domain-containing protein ENL, but not its paralogue AF9, is required for disease maintenance in acute myeloid leukaemia. CRISPR-Cas9-mediated depletion of ENL led to anti-leukaemic effects, including increased terminal myeloid differentiation and suppression of leukaemia growth in vitro and in vivo. Biochemical and crystal structural studies and chromatin-immunoprecipitation followed by sequencing analyses revealed that ENL binds to acetylated histone H3, and co-localizes with H3K27ac and H3K9ac on the promoters of actively transcribed genes that are essential for leukaemia. Disrupting the interaction between the YEATS domain and histone acetylation via structure-based mutagenesis reduced the recruitment of RNA polymerase II to ENL-target genes, leading to the suppression of oncogenic gene expression programs. Notably, disrupting the functionality of ENL further sensitized leukaemia cells to BET inhibitors. Together, our data identify ENL as a histone acetylation reader that regulates oncogenic transcriptional programs in acute myeloid leukaemia, and suggest that displacement of ENL from chromatin may be a promising epigenetic therapy, alone or in combination with BET inhibitors, for aggressive leukaemia.

Inhibitory effects of Agaricus blazei extracts on human myeloid leukemia cells.

PubMed

Kim, Chi-Fai; Jiang, Jing-Jing; Leung, Kwok-Nam; Fung, Kwok-Pui; Lau, Clara Bik-San

2009-03-18

Agaricus blazei has been used as an adjuvant in cancer chemotherapy and is found to inhibit the growth of various types of tumor cells. Our study has adopted a systematic and bioassay-guided approach to optimize the extraction of Agaricus blazei for anti-leukemic bioactive components. The tumor-selective growth inhibitory activity of the extracts on leukemic cell lines was evaluated in vitro and in vivo using tumor-bearing nude mice. Agaricus blazei extracts were prepared using different methods. MTT and tritiated thymidine incorporation assays were used to evaluate the in vitro anti-leukemic effects. The most potent extract was further investigated using NB-4 cells-bearing nude mice and mechanistic studies using DNA fragmentation assay and cell death detection ELISA. The JAB80E70 extract showed the most potent tumor-selective growth inhibitory activity against human leukemia NB-4 and K-562 cells. This is the first report of anti-leukemic activity of JAB80E70 in athymic nude mice bearing NB-4 cells. Using DNA fragmentation assays and cell death detection ELISA, JAB80E70 was found to induce apoptosis in NB-4 cells. However, the polysaccharide enriched fractions failed to show significant cytotoxicity on NB-4 cells in vitro. The JAB80E70 extract exhibited potent anti-leukemic effect in vitro and in vivo. The effect can be attributed, at least in part, to the induction of apoptosis. Besides, polysaccharides in Agaricus blazei may not possess direct anti-leukemic activity in vitro.

Nitric oxide-releasing nanoparticles: synthesis, characterization, and cytotoxicity to tumorigenic cells

NASA Astrophysics Data System (ADS)

Pelegrino, Milena T.; Silva, Letícia C.; Watashi, Carolina M.; Haddad, Paula S.; Rodrigues, Tiago; Seabra, Amedea B.

2017-02-01

Nitric oxide (NO) is involved in several biological processes, including toxicity against tumor cells. The aim of this study was to synthesize, characterize, and evaluate the cytotoxicity of NO-releasing chitosan nanoparticles. A thiol-containing molecule, mercaptosuccinic acid (MSA), was encapsulated (encapsulation efficiency of 99%) in chitosan/sodium tripolyphosphate nanoparticles (CS NPs). The obtained nanoparticles showed an average hydrodynamic size of 108.40 ± 0.96 nm and polydispersity index of 0.26 ± 0.01. MSA-CS NPs were nitrosated leading to S-nitroso-MSA-CS NPs, which act as NO donor. The cytotoxicity of CS NPs, MSA-CS NPs, and S-nitroso-MSA-CS NPs were evaluated in several tumor cells, including human hepatocellular carcinoma (HepG2), mouse melanoma (B16F10), and human chronic myeloid leukemia (K562) cell lines and Lucena-1, a vincristine-resistant K562 cell line. Both CS NPs and MSA-CS NPs did not cause toxic effects in these cells, whereas S-nitroso-MSA-CS NPs caused potent cytotoxic effects in all the tested tumor cell lines. The half-maximal inhibitory concentration values of S-nitroso-MSA-CS NPs were 19.7, 10.5, 22.8, and 27.8 μg·mL-1 for HepG2, B16F10, K562, and Lucena-1 cells, respectively. In contrast, S-nitroso-MSA-CS NPs exhibited lower cytotoxic to non-tumorigenic melanocytes (Melan-A) when compared with melanoma B16F10. Therefore, the results highlight the potential use of NO-releasing CS NPs in antitumor chemotherapy.

Myeloid leukemia factor 1 stabilizes tumor suppressor C/EBPα to prevent Trib1-driven acute myeloid leukemia.

PubMed

Nakamae, Ikuko; Kato, Jun-Ya; Yokoyama, Takashi; Ito, Hidenori; Yoneda-Kato, Noriko

2017-09-12

C/EBPα is a key transcription factor regulating myeloid differentiation and leukemogenesis. The Trib1-COP1 complex is an E3 ubiquitin ligase that targets C/EBPα for degradation, and its overexpression specifically induces acute myeloid leukemia (AML). Here we show that myeloid leukemia factor 1 (MLF1) stabilizes C/EBPα protein levels by inhibiting the ligase activity of the Trib1-COP1 complex. MLF1 directly interacts with COP1 in the nucleus and interferes with the formation of the Trib1-COP1 complex, thereby blocking its ability to polyubiquitinate C/EBPα for degradation. MLF1 overexpression suppressed the Trib1-induced growth advantage in a murine bone marrow (BM) culture and Trib1-induced AML development in BM-transplanted mouse models. MLF1 was expressed in hematopoietic stem cells and myeloid progenitors (common myeloid progenitors and granulocyte-macrophage progenitors) in normal hematopoiesis, which is consistent with the distribution of C/EBPα. An MLF1 deficiency conferred a more immature phenotype on Trib1-induced AML development. A higher expression ratio of Trib1 to MLF1 was a key determinant for AML development in mouse models, which was also confirmed in human patient samples with acute leukemia. These results indicate that MLF1 is a positive regulator that is critical for C/EBPα stability in the early phases of hematopoiesis and leukemogenesis.

Myeloid leukemia factor 1 stabilizes tumor suppressor C/EBPα to prevent Trib1-driven acute myeloid leukemia

PubMed Central

Nakamae, Ikuko; Kato, Jun-ya; Yokoyama, Takashi; Ito, Hidenori

2017-01-01

C/EBPα is a key transcription factor regulating myeloid differentiation and leukemogenesis. The Trib1-COP1 complex is an E3 ubiquitin ligase that targets C/EBPα for degradation, and its overexpression specifically induces acute myeloid leukemia (AML). Here we show that myeloid leukemia factor 1 (MLF1) stabilizes C/EBPα protein levels by inhibiting the ligase activity of the Trib1-COP1 complex. MLF1 directly interacts with COP1 in the nucleus and interferes with the formation of the Trib1-COP1 complex, thereby blocking its ability to polyubiquitinate C/EBPα for degradation. MLF1 overexpression suppressed the Trib1-induced growth advantage in a murine bone marrow (BM) culture and Trib1-induced AML development in BM-transplanted mouse models. MLF1 was expressed in hematopoietic stem cells and myeloid progenitors (common myeloid progenitors and granulocyte-macrophage progenitors) in normal hematopoiesis, which is consistent with the distribution of C/EBPα. An MLF1 deficiency conferred a more immature phenotype on Trib1-induced AML development. A higher expression ratio of Trib1 to MLF1 was a key determinant for AML development in mouse models, which was also confirmed in human patient samples with acute leukemia. These results indicate that MLF1 is a positive regulator that is critical for C/EBPα stability in the early phases of hematopoiesis and leukemogenesis. PMID:29296815

Meisoindigo is a promising agent with in vitro and in vivo activity against human acute myeloid leukemia.

PubMed

Lee, Chin-Cheng; Lin, Che-Pin; Lee, Yueh-Lun; Wang, Giueng-Chueng; Cheng, Yuan-Chih; Liu, H Eugene

2010-05-01

Meisoindigo, a derivative of Indigo naturalis, has been used in China for chronic myeloid leukemia. In vitro cell line studies have shown that this agent might induce apoptosis and myeloid differentiation of acute myeloid leukemia (AML). In this study, we explored its mechanisms and potential in AML. NB4, HL-60, and U937 cells and primary AML cells were used to examine its effects and the NOD/SCID animal model was used to evaluate its in vivo activity. Meisoindigo inhibited the growth of leukemic cells by inducing marked apoptosis and moderate cell-cycle arrest at the G(0)/G(1) phase. It down-regulated anti-apoptotic Bcl-2, and up-regulated pro-apoptotic Bak and Bax and cell-cycle related proteins, p21and p27. Furthermore, it induced myeloid differentiation, as demonstrated by morphologic changes, up-regulation of CD11b, and increased nitroblue tetrazolium reduction activity in all cell lines tested. In addition, meisoindigo down-regulated the expression of human telomerase reverse transcriptase and enhanced the cytotoxicity of conventional chemotherapeutic agents, cytarabine and idarubicin. As with the results from cell lines, meisoindigo also induced apoptosis, up-regulated p21 and p27, and down-regulated Bcl-2 in primary AML cells. The in vivo anti-leukemic activity of meisoindigo was also demonstrated by decreased spleen size in a dose-dependent manner. Taking these results together, meisoindigo is a potential agent for AML.

Expression of the pol gene of human endogenous retroviruses HERV-K and -W in leukemia patients.

PubMed

Bergallo, Massimiliano; Montanari, Paola; Mareschi, Katia; Merlino, Chiara; Berger, Massimo; Bini, Ilaria; Daprà, Valentina; Galliano, Ilaria; Fagioli, Franca

2017-12-01

The human endogenous retroviruses (HERVs) are a family of endogenous retroviruses that integrated into the germ cell DNA of primates over 30 million years ago. HERV expression seems impaired in several diseases, ranging from autoimmune to neoplastic disorders. The purpose of this study was to evaluate the overall endogenous retroviral transcription profile in bone marrow (BM) samples. A total of 30 paediatric high-risk leukaemia patients (lymphoid and myeloid malignancies) were tested for HERVs virus gene expression. Our findings show that HERV-K expression was significantly higher in leukaemia patients when compared to healthy donors of a similar median age. We observed a significantly high expression of HERV-K in acute lymphoblastic leukemia (ALL) patients. In this study, we also found a relative overexpression of the endogenous retrovirus HERV-K in BM cells from the majority of leukemia samples analyzed, in particular in ALL. This overexpression might be related to lymphatic leukemogenesis and it warrants further investigations.

Effect of carbamate pesticides on perforin, granzymes A-B-3/K, and granulysin in human natural killer cells.

PubMed

Li, Qing; Kobayashi, Maiko; Kawada, Tomoyuki

2015-09-01

We previously found that ziram, a carbamate pesticide, significantly reduced perforin, granzyme A (GrA), granzyme B (GrB), granzyme 3/K (Gr3/K), and granulysin (GRN) levels in NK-92MI cells, a human natural killer (NK) cell line. To investigate whether other carbamate pesticides also show similar toxicity on human NK cells, we conducted further experiments with NK-92CI cells, a human NK cell line, using a more sensitive assay. We previously confirmed that NK-92CI cells express CD56, perforin, GrA, GrB, Gr3/K, and GRN and are highly cytotoxic to K562 cells in a chromium release assay, which are more sensitive to organophosphorus pesticides and ziram than the NK-92MI cell line. NK-92CI cells were treated with ziram, thiram, maneb, or carbaryl at various concentrations for 4-24 h at 37°C in vitro. Thereafter, intracellular levels of perforin, GrA, GrB, Gr3/K, and GRN were determined by flow cytometry. It was found that all carbamate pesticides significantly reduced the intracellular levels of perforin, GrA, GrB, Gr3/K, and GRN in NK-92CI cells in a dose-dependent manner. However, the strength of the effect differed among the pesticides, and the order was thiram > ziram > maneb > carbaryl. In addition, it was also found that the degree of the reductions differed among the five proteins, with perforin more sensitive to pesticides than GRN, GrA, GrB, and Gr3/K, and the order was perforin > GRN > Gr3/K ≒ GrA ≒ GrB. © The Author(s) 2015.

Canthin-6-one induces cell death, cell cycle arrest and differentiation in human myeloid leukemia cells.

PubMed

Vieira Torquato, Heron F; Ribeiro-Filho, Antonio C; Buri, Marcus V; Araújo Júnior, Roberto T; Pimenta, Renata; de Oliveira, José Salvador R; Filho, Valdir C; Macho, Antonio; Paredes-Gamero, Edgar J; de Oliveira Martins, Domingos T

2017-04-01

Canthin-6-one is a natural product isolated from various plant genera and from fungi with potential antitumor activity. In the present study, we evaluate the antitumor effects of canthin-6-one in human myeloid leukemia lineages. Kasumi-1 lineage was used as a model for acute myeloid leukemia. Cells were treated with canthin-6-one and cell death, cell cycle and differentiation were evaluated in both total cells (Lin + ) and leukemia stem cell population (CD34 + CD38 - Lin -/low ). Among the human lineages tested, Kasumi-1 was the most sensitive to canthin-6-one. Canthin-6-one induced cell death with apoptotic (caspase activation, decrease of mitochondrial potential) and necrotic (lysosomal permeabilization, double labeling of annexin V/propidium iodide) characteristics. Moreover, canthin-6-one induced cell cycle arrest at G 0 /G 1 (7μM) and G 2 (45μM) evidenced by DNA content, BrdU incorporation and cyclin B1/histone 3 quantification. Canthin-6-one also promoted differentiation of Kasumi-1, evidenced by an increase in the expression of myeloid markers (CD11b and CD15) and the transcription factor PU.1. Furthermore, a reduction of the leukemic stem cell population and clonogenic capability of stem cells were observed. These results show that canthin-6-one can affect Kasumi-1 cells by promoting cell death, cell cycle arrest and cell differentiation depending on concentration used. Canthin-6-one presents an interesting cytotoxic activity against leukemic cells and represents a promising scaffold for the development of molecules for anti-leukemic applications, especially by its anti-leukemic stem cell activity. Copyright © 2017 Elsevier B.V. All rights reserved.

40 CFR 56.2 - Scope.

Code of Federal Regulations, 2011 CFR

2011-07-01

... procedures to be employed or policies to be followed by Regional Offices in implementing and enforcing the... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGIONAL CONSISTENCY § 56.2 Scope. This part covers actions taken by: (a) Employees in EPA Regional Offices, including Regional...

40 CFR 56.2 - Scope.

Code of Federal Regulations, 2010 CFR

2010-07-01

... procedures to be employed or policies to be followed by Regional Offices in implementing and enforcing the... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGIONAL CONSISTENCY § 56.2 Scope. This part covers actions taken by: (a) Employees in EPA Regional Offices, including Regional...

Downregulation of an Aim-1 Kinase Couples with Megakaryocytic Polyploidization of Human Hematopoietic Cells

PubMed Central

Kawasaki, Akira; Matsumura, Itaru; Miyagawa, Jun-ichiro; Ezoe, Sachiko; Tanaka, Hirokazu; Terada, Yasuhiko; Tatsuka, Masaaki; Machii, Takashi; Miyazaki, Hiroshi; Furukawa, Yusuke; Kanakura, Yuzuru

2001-01-01

During the late phase of megakaryopoiesis, megakaryocytes undergo polyploidization, which is characterized by DNA duplication without concomitant cell division. However, it remains unknown by which mechanisms this process occurs. AIM-1 and STK15 belong to the Aurora/increase-in-ploidy (Ipl)1 serine/threonine kinase family and play key roles in mitosis. In a human interleukin-3–dependent cell line, F-36P, the expressions of AIM-1 and STK15 mRNA were specifically observed at G2/M phase of the cell cycle during proliferation. In contrast, the expressions of AIM-1 and STK15 were continuously repressed during megakaryocytic polyploidization of human erythro/megakaryocytic cell lines (F-36P, K562, and CMK) treated with thrombopoietin, activated ras (H-rasG12V), or phorbol ester. Furthermore, their expressions were suppressed during thrombopoietin-induced polyploidization of normal human megakaryocytes. Activation of AIM-1 by the induced expression of AIM-1(wild-type) canceled TPA-induced polyploidization of K562 cells significantly, whereas that of STK15 did not. Moreover, suppression of AIM-1 by the induced expression of AIM-1 (K/R, dominant-negative type) led to polyploidization in 25% of K562 cells, whereas STK15(K/R) showed no effect. Also, the induced expression of AIM-1(K/R) in CMK cells provoked polyploidization up to 32N. These results suggested that downregulation of AIM-1 at M phase may be involved in abortive mitosis and polyploid formation of megakaryocytes. PMID:11266445

BAX/BCL-XL gene expression ratio inversely correlates with disease progression in chronic myeloid leukemia.

PubMed

Gonzalez, Mariana S; De Brasi, Carlos D; Bianchini, Michele; Gargallo, Patricia; Moiraghi, Beatriz; Bengió, Raquel; Larripa, Irene B

2010-10-15

BCR-ABL fusion gene is implicated in the pathogenesis of chronic myeloid leukemia (CML), encoding the oncoprotein p210(BCR-ABL) with anti-apoptotic activity. The inability to undergo apoptosis is an important mechanism of drug resistance and neoplastic evolution in CML. The gene transcript expression of mitochondrial apoptotic related genes BAX and BCL-XL was evaluated by quantitative Real Time PCR (qPCR) in vitro in K562 cells and in vivo in peripheral blood of 66 CML patients in different stages of the disease: 13 cases at diagnosis, 34 in chronic phase (CP), 10 in accelerated phase (AP) and 9 in blast crisis (BC). Our results in K562 cells showed that all treatments with different tyrosine kinase inhibitors (TKIs) induced a decreased expression of the antiapoptotic oncogene BCL-XL, whereas the proapoptotic gene BAX remains constant with minor modifications. A significantly lower BAX/BCL-XL expression ratio (mean±SEM) than a group of healthy individuals (4.8±0.59) were observed in CML patients at diagnosis (1.28 ± 0.16), in AP (1.14±0.20), in BC (1.16±0.30) and in 18% of cases of patients in CP (2.71±0.40). Most CP cases (82%) showed a significantly increased ratio (10.03±1.30), indicating that the treatment with TKIs efficiently inhibited the expression of BCL-XL by blocking BCR-ABL oncoprotein. The BAX/BCL-XL ratio showed a significant inverse correlation (Spearman P<0.0001) with BCR-ABL/ABL relative expression indicating that low BAX/BCL-XL was associated with disease progression. Accordingly, the follow up of a cohort of eight cases during 6months from diagnosis showed that while the BAX/BCL-XL ratio rapidly increased after treatment in seven cases with good evolution, it decreased in the single case that showed rapid evolution and short survival. Our data suggest that BAX/BCL-XL expression ratio may be a sensitive monitor of disease progression and an early predictor of TKI therapy responsiveness in CML patients. Copyright © 2010 Elsevier Inc. All

31 CFR 562.311 - United States person; U.S. person.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false United States person; U.S. person. 562.311 Section 562.311 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued... laws of the United States or any jurisdiction within the United States (including foreign branches), or...

31 CFR 562.311 - United States person; U.S. person.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false United States person; U.S. person. 562.311 Section 562.311 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued... laws of the United States or any jurisdiction within the United States (including foreign branches), or...

Induced pluripotent stem cell-derived myeloid phagocytes: disease modeling and therapeutic applications.

PubMed

Goodridge, Helen S

2014-06-01

Myeloid phagocytes (neutrophils, monocytes, macrophages and dendritic cells) have key roles in immune defense, as well as in tissue repair and remodeling. Defective or dysregulated myeloid phagocyte production or function can cause immune dysfunction, blood cell malignancies and inflammatory diseases. The tumor microenvironment can also condition myeloid phagocytes to promote tumor growth. Studies of their physiological and pathophysiological roles and the mechanisms regulating their production and function are crucial for the identification of novel therapeutic targets. In this review, we examine the use of induced pluripotent stem cells to study myeloid phagocytes in human diseases and develop future therapeutic strategies. Copyright © 2014 Elsevier Ltd. All rights reserved.

RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Houcai; Yu, Jing; Zhang, Lixia

2014-04-18

Highlights: • RPS27a expression was up-regulated in advanced-phase CML and AL patients. • RPS27a knockdown changed biological property of K562 and K562/G01 cells. • RPS27a knockdown affected Raf/MEK/ERK, P21 and BCL-2 signaling pathways. • RPS27a knockdown may be applicable for new combination therapy in CML patients. - Abstract: Ribosomal protein S27a (RPS27a) could perform extra-ribosomal functions besides imparting a role in ribosome biogenesis and post-translational modifications of proteins. The high expression level of RPS27a was reported in solid tumors, and we found that the expression level of RPS27a was up-regulated in advanced-phase chronic myeloid leukemia (CML) and acute leukemia (AL)more » patients. In this study, we explored the function of RPS27a in leukemia cells by using CML cell line K562 cells and its imatinib resistant cell line K562/G01 cells. It was observed that the expression level of RPS27a was high in K562 cells and even higher in K562/G01 cells. Further analysis revealed that RPS27a knockdown by shRNA in both K562 and K562G01 cells inhibited the cell viability, induced cell cycle arrest at S and G2/M phases and increased cell apoptosis induced by imatinib. Combination of shRNA with imatinib treatment could lead to more cleaved PARP and cleaved caspase-3 expression in RPS27a knockdown cells. Further, it was found that phospho-ERK(p-ERK) and BCL-2 were down-regulated and P21 up-regulated in RPS27a knockdown cells. In conclusion, RPS27a promotes proliferation, regulates cell cycle progression and inhibits apoptosis of leukemia cells. It appears that drugs targeting RPS27a combining with tyrosine kinase inhibitor (TKI) might represent a novel therapy strategy in TKI resistant CML patients.« less

CD8+ T-cell immunosurveillance constrains lymphoid pre-metastatic myeloid cell accumulation

PubMed Central

Li, Wenzhao; Deng, Jiehui; Herrmann, Andreas; Priceman, Saul J.; Liang, Wei; Shen, Shudan; Pal, Sumanta K.; Hoon, Dave S.B.; Yu, Hua

2014-01-01

Increasing evidence suggests that pre-metastatic niches, consisting mainly of myeloid cells, provide microenvironment critical for cancer cell recruitment and survival to facilitate metastasis. While CD8+ T cells exert immunosurveillance in primary human tumors, whether they can exert similar effects on myeloid cells in the pre-metastatic environment is unknown. Here, we show that CD8+ T cells are capable of constraining pre-metastatic myeloid cell accumulation by inducing myeloid cell apoptosis in C57BL/6 mice. Antigen-specific CD8+ T-cell cytotoxicity against myeloid cells in pre-metastatic lymph nodes is compromised by Stat3. We demonstrate here that Stat3 ablation in myeloid cells leads to CD8+ T-cell activation and increased levels of IFN-γ and granzyme B in the pre-metastatic environment. Furthermore, Stat3 negatively regulates soluble antigen cross-presentation by myeloid cells to CD8+ T cells in the pre-metastatic niche. Importantly, in tumor-free lymph nodes of melanoma patients, infiltration of activated CD8+ T cells inversely correlates with STAT3 activity, which is associated with a decrease in number of myeloid cells. Our study suggested a novel role for CD8+ T cells in constraining myeloid cell activity through direct killing in the pre-metastatic environment, and the therapeutic potential by targeting Stat3 in myeloid cells to improve CD8+ T-cell immunosurveillance against metastasis. PMID:25310972

Dual inhibition of Bcl-2 and Bcl-xL strikingly enhances PI3K inhibition-induced apoptosis in human myeloid leukemia cells through a GSK3- and Bim-dependent mechanism.

PubMed

Rahmani, Mohamed; Aust, Mandy Mayo; Attkisson, Elisa; Williams, David C; Ferreira-Gonzalez, Andrea; Grant, Steven

2013-02-15

Effects of concomitant inhibition of the PI3K/AKT/mTOR pathway and Bcl-2/Bcl-xL (BCL2L1) were examined in human myeloid leukemia cells. Tetracycline-inducible Bcl-2 and Bcl-xL dual knockdown sharply increased PI3K/AKT/mTOR inhibitor lethality. Conversely, inducible knockdown or dominant-negative AKT increased, whereas constitutively active AKT reduced lethality of the Bcl-2/Bcl-xL inhibitor ABT-737. Furthermore, PI3K/mTOR inhibitors (e.g., BEZ235 and PI-103) synergistically increased ABT-737-mediated cell death in multiple leukemia cell lines and reduced colony formation in leukemic, but not normal, CD34+ cells. Notably, increased lethality was observed in four of six primary acute myelogenous leukemia (AML) specimens. Responding, but not nonresponding, samples exhibited basal AKT phosphorylation. PI3K/mTOR inhibitors markedly downregulated Mcl-1 but increased Bim binding to Bcl-2/Bcl-xL; the latter effect was abrogated by ABT-737. Combined treatment also markedly diminished Bax/Bak binding to Mcl-1, Bcl-2, or Bcl-xL. Bax, Bak, or Bim (BCL2L11) knockdown or Mcl-1 overexpression significantly diminished regimen-induced apoptosis. Interestingly, pharmacologic inhibition or short hairpin RNA knockdown of GSK3α/β significantly attenuated Mcl-1 downregulation and decreased apoptosis. In a systemic AML xenograft model, dual tetracycline-inducible knockdown of Bcl-2/Bcl-xL sharply increased BEZ235 antileukemic effects. In a subcutaneous xenograft model, BEZ235 and ABT-737 coadministration significantly diminished tumor growth, downregulated Mcl-1, activated caspases, and prolonged survival. Together, these findings suggest that antileukemic synergism between PI3K/AKT/mTOR inhibitors and BH3 mimetics involves multiple mechanisms, including Mcl-1 downregulation, release of Bim from Bcl-2/Bcl-xL as well as Bak and Bax from Mcl-1/Bcl-2/Bcl-xL, and GSK3α/β, culminating in Bax/Bak activation and apoptosis. They also argue that combining PI3K/AKT/mTOR inhibitors with BH3

Antileukaemic effect of PI3K-mTOR inhibitors in acute myeloid leukaemia-gene expression profiles reveal CDC25B expression as determinate of pharmacological effect.

PubMed

Reikvam, Håkon; Tamburini, Jerome; Skrede, Silje; Holdhus, Rita; Poulain, Laury; Ersvaer, Elisabeth; Hatfield, Kimberley J; Bruserud, Øystein

2014-01-01

Acute myeloid leukaemia (AML) is a heterogeneous malignancy. Intracellular signalling through the phosphatidylinositol 3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway is important for regulation of cellular growth and metabolism, and inhibitors of this pathway is considered for AML treatment. Primary human AML cells, derived from 96 consecutive adult patients, were examined. The effects of two mTOR inhibitors (rapamycin, temsirolimus) and two PI3K inhibitors (GDC-0941, 3-methyladenine) were studied, and we investigated cytokine-dependent proliferation, regulation of apoptosis and global gene expression profiles. Only a subset of patients demonstrated strong antiproliferative effects of PI3K-mTOR inhibitors. Unsupervised hierarchical clustering analysis identified two main clusters of patients; one subset showing weak or absent antiproliferative effects (59%) and another group showing a strong growth inhibition for all drugs and concentrations examined (41%). Global gene expression analyses showed that patients with AML cell resistance against PI3K-mTOR inhibitors showed increased mRNA expression of the CDC25B gene that encodes the cell cycle regulator Cell Division Cycle 25B. The antileukaemic effect of PI3K-Akt-mTOR inhibition varies between patients, and resistance to these inhibitors is associated with the expression of the cell cycle regulator CDC25B, which is known to crosstalk with the PI3K-Akt-mTOR pathway and mediate rapamycin resistance in experimental models. © 2013 John Wiley & Sons Ltd.

Burkholderia cenocepacia K56-2 trimeric autotransporter adhesin BcaA binds TNFR1 and contributes to induce airway inflammation.

PubMed

Mil-Homens, Dalila; Pinto, Sandra N; Matos, Rute G; Arraiano, Cecília; Fialho, Arsenio M

2017-04-01

Chronic lung disease caused by persistent bacterial infections is a major cause of morbidity and mortality in patients with cystic fibrosis (CF). CF pathogens acquire antibiotic resistance, overcome host defenses, and impose uncontrolled inflammation that ultimately may cause permanent damage of lungs' airways. Among the multiple CF-associated pathogens, Burkholderia cenocepacia and other Burkholderia cepacia complex bacteria have become prominent contributors of disease progression. Here, we demonstrate that BcaA, a trimeric autotransporter adhesin (TAA) from the epidemic strain B. cenocepacia K56-2, is a tumor necrosis factor receptor 1-interacting protein able to regulate components of the tumor necrosis factor signaling pathway and ultimately leading to a significant production of the proinflammatory cytokine IL-8. Notably, this study is the first to demonstrate that a protein belonging to the TAA family is involved in the induction of the inflammatory response during B. cenocepacia infections, contributing to the success of the pathogen. Moreover, our results reinforce the relevance of the TAA BcaA as a multifunctional protein with a major role in B. cenocepacia virulence. © 2016 John Wiley & Sons Ltd.

miR-181a promotes G1/S transition and cell proliferation in pediatric acute myeloid leukemia by targeting ATM.

PubMed

Liu, Xiaodan; Liao, Wang; Peng, Hongxia; Luo, Xuequn; Luo, Ziyan; Jiang, Hua; Xu, Ling

2016-01-01

Abnormal expression of miRNAs is intimately related to a variety of human cancers. The purpose of this study is to confirm the expression of miR-181a and elucidate its physiological function and mechanism in pediatric acute myeloid leukemia (AML). Pediatric AML patients and healthy controls were enrolled, and the expression of miR-181a and ataxia telangiectasia mutated (ATM) in tissues were examined using quantitative PCR. Moreover, cell proliferation and cell cycle were evaluated in several cell lines (HL60, NB4 and K562) by using flow cytometry after transfected with miR-181a mimics and inhibitors, or ATM siRNA and control siRNA. Finally, ATM as the potential target protein of miR-181a was examined. We found that miR-181a was significantly increased in pediatric AML, which showed an inverse association with ATM expression. Overexpressed miR-181a in cell lines significantly enhanced cell proliferation, as well as increased the ratio of S-phase cells by miR-181a mimics transfection in vitro. Luciferase activity of the reporter construct identified ATM as the direct molecular target of miR-181a. ATM siRNA transfection significantly enhanced cell proliferation and increased the ratio of S-phase cells in vitro. The results revealed novel mechanism through which miR-181a regulates G1/S transition and cell proliferation in pediatric AML by regulating the tumor suppressor ATM, providing insights into the molecular mechanism in pediatric AML.

Ajoene, a garlic-derived natural compound, enhances chemotherapy-induced apoptosis in human myeloid leukaemia CD34-positive resistant cells.

PubMed

Ahmed, N; Laverick, L; Sammons, J; Zhang, H; Maslin, D J; Hassan, H T

2001-01-01

The reputation of garlic as an effective remedy for tumours extends back to the Egyptian Codex Ebers of 1550 BC. Several garlic compounds, including allicin and its corresponding sulfide, inhibit the proliferation of several human malignant cells. Ajoene is a garlic-derived compound produced most efficiently from pure allicin and has the advantage of a greater chemical stability than allicin. Recently, ajoene was shown to inhibit proliferation and induce apoptosis of human leukaemia CD34-negative cells including HL-60, U937, HEL and OCIM-I. More significantly, ajoene was shown to induce 30% apoptosis in myeloblasts from a chronic myeloid leukaemia patient in blastic crisis. Acute myeloid leukaemia (AML) is a heterogeneous malignant disease in which disease progression at the level of CD34-positive cells has a major impact on resistance to chemotherapy and relapse. The aim of the present study was to investigate the effect of ajoene on changes in the expression of apoptosis-related proteins: bcl-2 and caspase-3, induced by two principal drugs used in treatment of AML, cytarabine and fludarabine, in KGI human myeloid leukaemia CD34-positive-resistant cells. Both quantitative ELISA measurement of bcl-2 and colourimetric measurement of active caspase-3 were used. Quantitative ELISA measurement of bcl-2 (units per million cells) showed treatment of KG1-resistant leukaemia cells with 40 microM ajoene alone to significantly reduce the bcl-2-expression from 239.5 +/- 1.5 in control cultures to only 22.0 +/- 4.0 in ajoene-treated cultures. Fludarabine had significantly more inhibitory effect on bcl-2-expression than cytarabine in KGI-resistant myeloid leukaemia cells. Ajoene significantly enhanced the inhibitory effect of the two chemotherapeutic drugs, cytarabine and fludarabine, on bcl-2-expression in KGI cells. Bcl-2-expression could not be detected in fludarabine + ajoene-treated cultures. The Western blot of bcl-2-expression in KGI control and treated cells confirmed

Testicular myeloid sarcoma: case report.

PubMed

Zago, Luzia Beatriz Ribeiro; Ladeia, Antônio Alexandre Lisbôa; Etchebehere, Renata Margarida; de Oliveira, Leonardo Rodrigues

2013-01-01

Myeloid sarcomas are extramedullary solid tumors composed of immature granulocytic precursor cells. In association with acute myeloid leukemia and other myeloproliferative disorders, they may arise concurrently with compromised bone marrow related to acute myeloid leukemia, as a relapsed presentation, or occur as the first manifestation. The testicles are considered to be an uncommon site for myeloid sarcomas. No therapeutic strategy has been defined as best but may include chemotherapy, radiotherapy and/or hematopoietic stem cell transplantation. This study reports the evolution of a patient with testicular myeloid sarcoma as the first manifestation of acute myeloid leukemia. The patient initially refused medical treatment and died five months after the clinical condition started.

25 CFR 162.562 - Must a lessee provide insurance for a WSR lease?

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 1 2014-04-01 2014-04-01 false Must a lessee provide insurance for a WSR lease? 162.562 Section 162.562 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER LEASES AND PERMITS Wind and Solar Resource Leases Wsr Lease Bonding and Insurance § 162.562 Must a lessee provide...

25 CFR 162.562 - Must a lessee provide insurance for a WSR lease?

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 1 2013-04-01 2013-04-01 false Must a lessee provide insurance for a WSR lease? 162.562 Section 162.562 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER LEASES AND PERMITS Wind and Solar Resource Leases Wsr Lease Bonding and Insurance § 162.562 Must a lessee provide...

Subcellular localization of full-length human myeloid leukemia factor 1 (MLF1) is independent of 14-3-3 proteins.

PubMed

Molzan, Manuela; Ottmann, Christian

2013-03-01

Myeloid leukemia factor 1 (MLF1) is associated with the development of leukemic diseases such as acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). However, information on the physiological function of MLF1 is limited and mostly derived from studies identifying MLF1 interaction partners like CSN3, MLF1IP, MADM, Manp and the 14-3-3 proteins. The 14-3-3-binding site surrounding S34 is one of the only known functional features of the MLF1 sequence, along with one nuclear export sequence (NES) and two nuclear localization sequences (NLS). It was recently shown that the subcellular localization of mouse MLF1 is dependent on 14-3-3 proteins. Based on these findings, we investigated whether the subcellular localization of human MLF1 was also directly 14-3-3-dependent. Live cell imaging with GFP-fused human MLF1 was used to study the effects of mutations and deletions on its subcellular localization. Surprisingly, we found that the subcellular localization of full-length human MLF1 is 14-3-3-independent, and is probably regulated by other as-yet-unknown proteins.

Anticancer activity of Sargassum oligocystum water extract against human cancer cell lines.

PubMed

Zandi, K; Ahmadzadeh, S; Tajbakhsh, S; Rastian, Z; Yousefi, F; Farshadpour, F; Sartavi, K

2010-08-01

Antitumor drug resistance and side effects of antitumor compounds are the most common problems in medicine. Therefore, finding new antitumor agents with low side effects could be interesting. This study was designed to assay antitumor activity of the extract from brown alga Sargassum oligocystum, gathered from Persian Gulf seashore, against K562 and Daudi human cancer cell lines. The research was performed as an in vitro study. The effect of the alga extract on proliferation of cell lines were measured by two methods: MTT assay and trypan blue exclusion test. The most effective antitumor activity has been shown at concentrations 500 microg/ml and 400 microg/ml of the alga extract against Daudi and K562 cell lines, respectively. The results showed that the extracts of brown alga Sargassum oligocystum have remarkable antitumor activity against K562 and Daudi cell lines. It is justified to be suggested for further research such as algal extract fractionation and purification and in vivo studies in order to formulate natural compounds with antitumor activities.

Cutaneous myeloid sarcoma: natural history and biology of an uncommon manifestation of acute myeloid leukemia.

PubMed

Hurley, M Yadira; Ghahramani, Grant K; Frisch, Stephanie; Armbrecht, Eric S; Lind, Anne C; Nguyen, Tudung T; Hassan, Anjum; Kreisel, Friederike H; Frater, John L

2013-05-01

We conducted a retrospective study of patients with cutaneous myeloid sarcoma, from 2 tertiary care institutions. Eighty-three patients presented, with a mean age of 52 years. Diagnosis of myeloid sarcoma in the skin was difficult due to the low frequency of myeloperoxidase and/or CD34+ cases (56% and 19% of tested cases, respectively). Seventy-one of the 83 patients (86%) had ≥ 1 bone marrow biopsy. Twenty-eight (39%) had acute myeloid leukemia with monocytic differentiation. Twenty-three had other de novo acute myeloid leukemia subtypes. Thirteen patients had other myeloid neoplasms, of which 4 ultimately progressed to an acute myeloid leukemia. Seven had no bone marrow malignancy. Ninety-eight percent of the patients received chemotherapy, and approximately 89% died of causes related to their disease. Cutaneous myeloid sarcoma in most cases represents an aggressive manifestation of acute myeloid leukemia. Diagnosis can be challenging due to lack of myeloblast-associated antigen expression in many cases, and difficulty in distinguishing monocyte-lineage blasts from neoplastic and non-neoplastic mature monocytes.

The 87-kD A gamma-globin enhancer-binding protein is a product of the HOXB2(HOX2H) locus.

PubMed

Sengupta, P K; Lavelle, D E; DeSimone, J

1994-03-01

Developmental regulation of globin gene expression may be controlled by developmental stage-specific nuclear proteins that influence interactions between the locus control region and local regulatory sequences near individual globin genes. We previously isolated an 87-kD nuclear protein from K562 cells that bound to DNA sequences in the beta-globin locus control region, gamma-globin promoter, and A gamma-globin enhancer. The presence of this protein in fetal globin-expressing cells and its absence in adult globin-expressing cells suggested that it may be a developmental stage-specific factor. A lambda gt11 K562 cDNA clone encoding a portion of the HOXB2 (formerly HOX2H) homeobox gene was isolated on the basis of the ability of its beta-galactosidase fusion protein to bind to the same DNA sequences as the 87-kD K562 protein. Because no other relationship had been established between the 87-kD K562 protein and the HOXB2 protein other than their ability to bind ot the same DNA sequences, we have investigated whether the two proteins are related antigenically. Our data show that antisera produced against the HOXB2-beta-gal fusion protein and a synthetic HOXB2 decapeptide react specifically with an 87-kD protein from K562 nuclear extract, showing that the 87-kD K562 nuclear protein is a product of the HOXB2 locus, and is the first demonstration of cellular HOXB2 protein.

12 CFR 562.2 - Regulatory reports.

Code of Federal Regulations, 2010 CFR

2010-01-01

... § 562.2 Regulatory reports. (a) Definition and scope. This section applies to all regulatory reports, as... (TFR) are examples of regulatory reports. Regulatory reports are regulatory documents, not accounting... limited to, the accounting instructions provided in the TFR, guidance contained in OTS regulations...

The DNA Inflammasome in Human Myeloid Cells Is Initiated by a STING-Cell Death Program Upstream of NLRP3

PubMed Central

Gaidt, Moritz M.; Ebert, Thomas S.; Chauhan, Dhruv; Ramshorn, Katharina; Pinci, Francesca; Zuber, Sarah; O’Duill, Fionan; Schmid-Burgk, Jonathan L.; Hoss, Florian; Buhmann, Raymund; Wittmann, Georg; Latz, Eicke; Subklewe, Marion; Hornung, Veit

2018-01-01

Summary Detection of cytosolic DNA constitutes a central event in the context of numerous infectious and sterile inflammatory conditions. Recent studies have uncovered a bipartite mode of cytosolic DNA recognition, in which the cGAS-STING axis triggers antiviral immunity, whereas AIM2 triggers inflammasome activation. Here, we show that AIM2 is dispensable for DNA-mediated inflammasome activation in human myeloid cells. Instead, detection of cytosolic DNA by the cGAS-STING axis induces a cell death program initiating potassium efflux upstream of NLRP3. Forward genetics identified regulators of lysosomal trafficking to modulate this cell death program, and subsequent studies revealed that activated STING traffics to the lysosome, where it triggers membrane permeabilization and thus lysosomal cell death (LCD). Importantly, the cGAS-STING-NLRP3 pathway constitutes the default inflammasome response during viral and bacterial infections in human myeloid cells. We conclude that targeting the cGAS-STING-LCD-NLRP3 pathway will ameliorate pathology in inflammatory conditions that are associated with cytosolic DNA sensing. PMID:29033128

The combinatorial PP1-binding consensus Motif (R/K)x( (0,1))V/IxFxx(R/K)x(R/K) is a new apoptotic signature.

PubMed

Godet, Angélique N; Guergnon, Julien; Maire, Virginie; Croset, Amélie; Garcia, Alphonse

2010-04-01

Previous studies established that PP1 is a target for Bcl-2 proteins and an important regulator of apoptosis. The two distinct functional PP1 consensus docking motifs, R/Kx((0,1))V/IxF and FxxR/KxR/K, involved in PP1 binding and cell death were previously characterized in the BH1 and BH3 domains of some Bcl-2 proteins. In this study, we demonstrate that DPT-AIF(1), a peptide containing the AIF(562-571) sequence located in a c-terminal domain of AIF, is a new PP1 interacting and cell penetrating molecule. We also showed that DPT-AIF(1) provoked apoptosis in several human cell lines. Furthermore, DPT-APAF(1) a bi-partite cell penetrating peptide containing APAF-1(122-131), a non penetrating sequence from APAF-1 protein, linked to our previously described DPT-sh1 peptide shuttle, is also a PP1-interacting death molecule. Both AIF(562-571) and APAF-1(122-131) sequences contain a common R/Kx((0,1))V/IxFxxR/KxR/K motif, shared by several proteins involved in control of cell survival pathways. This motif combines the two distinct PP1c consensus docking motifs initially identified in some Bcl-2 proteins. Interestingly DPT-AIF(2) and DPT-APAF(2) that carry a F to A mutation within this combinatorial motif, no longer exhibited any PP1c binding or apoptotic effects. Moreover the F to A mutation in DPT-AIF(2) also suppressed cell penetration. These results indicate that the combinatorial PP1c docking motif R/Kx((0,1))V/IxFxxR/KxR/K, deduced from AIF(562-571) and APAF-1(122-131) sequences, is a new PP1c-dependent Apoptotic Signature. This motif is also a new tool for drug design that could be used to characterize potential anti-tumour molecules.

Role of glycolysis inhibition and poly(ADP-ribose) polymerase activation in necrotic-like cell death caused by ascorbate/menadione-induced oxidative stress in K562 human chronic myelogenous leukemic cells.

PubMed

Verrax, Julien; Vanbever, Stéphanie; Stockis, Julie; Taper, Henryk; Calderon, Pedro Buc

2007-03-15

Among different features of cancer cells, two of them have retained our interest: their nearly universal glycolytic phenotype and their sensitivity towards an oxidative stress. Therefore, we took advantage of these features to develop an experimental approach by selectively exposing cancer cells to an oxidant insult induced by the combination of menadione (vitamin K(3)) and ascorbate (vitamin C). Ascorbate enhances the menadione redox cycling, increases the formation of reactive oxygen species and kills K562 cells as shown by more than 65% of LDH leakage after 24 hr of incubation. Since both lactate formation and ATP content are depressed by about 80% following ascorbate/menadione exposure, we suggest that the major intracellular event involved in such a cytotoxicity is related to the impairment of glycolysis. Indeed, NAD(+) is rapidly and severely depleted, a fact most probably related to a strong Poly(ADP-ribose) polymerase (PARP) activation, as shown by the high amount of poly-ADP-ribosylated proteins. The addition of N-acetylcysteine (NAC) restores most of the ATP content and the production of lactate as well. The PARP inhibitor dihydroxyisoquinoline (DiQ) was able to partially restore both parameters as well as cell death induced by ascorbate/menadione. These results suggest that the PARP activation induced by the oxidative stress is a major but not the only intracellular event involved in cell death by ascorbate/menadione. Due to the high energetic dependence of cancer cells on glycolysis, the impairment of such an essential pathway may explain the effectiveness of this combination to kill cancer cells. (c) 2006 Wiley-Liss, Inc.

The chimeric ubiquitin ligase SH2-U-box inhibits the growth of imatinib-sensitive and resistant CML by targeting the native and T315I-mutant BCR-ABL

PubMed Central

Ru, Yi; Wang, Qinhao; Liu, Xiping; Zhang, Mei; Zhong, Daixing; Ye, Mingxiang; Li, Yuanchun; Han, Hua; Yao, Libo; Li, Xia

2016-01-01

Chronic myeloid leukemia (CML) is characterized by constitutively active fusion protein tyrosine kinase BCR-ABL. Although the tyrosine kinase inhibitor (TKI) against BCR-ABL, imatinib, is the first-line therapy for CML, acquired resistance almost inevitably emerges. The underlying mechanism are point mutations within the BCR-ABL gene, among which T315I is notorious because it resists to almost all currently available inhibitors. Here we took use of a previously generated chimeric ubiquitin ligase, SH2-U-box, in which SH2 from the adaptor protein Grb2 acts as a binding domain for activated BCR-ABL, while U-box from CHIP functions as an E3 ubiquitin ligase domain, so as to target the ubiquitination and degradation of both native and T315I-mutant BCR-ABL. As such, SH2-U-box significantly inhibited proliferation and induced apoptosis in CML cells harboring either the wild-type or T315I-mutant BCR-ABL (K562 or K562R), with BCR-ABL-dependent signaling pathways being repressed. Moreover, SH2-U-box worked in concert with imatinib in K562 cells. Importantly, SH2-U-box-carrying lentivirus could markedly suppress the growth of K562-xenografts in nude mice or K562R-xenografts in SCID mice, as well as that of primary CML cells. Collectively, by degrading the native and T315I-mutant BCR-ABL, the chimeric ubiquitin ligase SH2-U-box may serve as a potential therapy for both imatinib-sensitive and resistant CML. PMID:27329306

The chimeric ubiquitin ligase SH2-U-box inhibits the growth of imatinib-sensitive and resistant CML by targeting the native and T315I-mutant BCR-ABL.

PubMed

Ru, Yi; Wang, Qinhao; Liu, Xiping; Zhang, Mei; Zhong, Daixing; Ye, Mingxiang; Li, Yuanchun; Han, Hua; Yao, Libo; Li, Xia

2016-06-22

Chronic myeloid leukemia (CML) is characterized by constitutively active fusion protein tyrosine kinase BCR-ABL. Although the tyrosine kinase inhibitor (TKI) against BCR-ABL, imatinib, is the first-line therapy for CML, acquired resistance almost inevitably emerges. The underlying mechanism are point mutations within the BCR-ABL gene, among which T315I is notorious because it resists to almost all currently available inhibitors. Here we took use of a previously generated chimeric ubiquitin ligase, SH2-U-box, in which SH2 from the adaptor protein Grb2 acts as a binding domain for activated BCR-ABL, while U-box from CHIP functions as an E3 ubiquitin ligase domain, so as to target the ubiquitination and degradation of both native and T315I-mutant BCR-ABL. As such, SH2-U-box significantly inhibited proliferation and induced apoptosis in CML cells harboring either the wild-type or T315I-mutant BCR-ABL (K562 or K562R), with BCR-ABL-dependent signaling pathways being repressed. Moreover, SH2-U-box worked in concert with imatinib in K562 cells. Importantly, SH2-U-box-carrying lentivirus could markedly suppress the growth of K562-xenografts in nude mice or K562R-xenografts in SCID mice, as well as that of primary CML cells. Collectively, by degrading the native and T315I-mutant BCR-ABL, the chimeric ubiquitin ligase SH2-U-box may serve as a potential therapy for both imatinib-sensitive and resistant CML.

Cell-to-Cell Contact and Nectin-4 Govern Spread of Measles Virus from Primary Human Myeloid Cells to Primary Human Airway Epithelial Cells.

PubMed

Singh, Brajesh K; Li, Ni; Mark, Anna C; Mateo, Mathieu; Cattaneo, Roberto; Sinn, Patrick L

2016-08-01

Measles is a highly contagious, acute viral illness. Immune cells within the airways are likely first targets of infection, and these cells traffic measles virus (MeV) to lymph nodes for amplification and subsequent systemic dissemination. Infected immune cells are thought to return MeV to the airways; however, the mechanisms responsible for virus transfer to pulmonary epithelial cells are poorly understood. To investigate this process, we collected blood from human donors and generated primary myeloid cells, specifically, monocyte-derived macrophages (MDMs) and dendritic cells (DCs). MDMs and DCs were infected with MeV and then applied to primary cultures of well-differentiated airway epithelial cells from human donors (HAE). Consistent with previous results obtained with free virus, infected MDMs or DCs were incapable of transferring MeV to HAE when applied to the apical surface. Likewise, infected MDMs or DCs applied to the basolateral surface of HAE grown on small-pore (0.4-μm) support membranes did not transfer virus. In contrast, infected MDMs and DCs applied to the basolateral surface of HAE grown on large-pore (3.0-μm) membranes successfully transferred MeV. Confocal microscopy demonstrated that MDMs and DCs are capable of penetrating large-pore membranes but not small-pore membranes. Further, by using a nectin-4 blocking antibody or recombinant MeV unable to enter cells through nectin-4, we demonstrated formally that transfer from immune cells to HAE occurs in a nectin-4-dependent manner. Thus, both infected MDMs and DCs rely on cell-to-cell contacts and nectin-4 to efficiently deliver MeV to the basolateral surface of HAE. Measles virus spreads rapidly and efficiently in human airway epithelial cells. This rapid spread is based on cell-to-cell contact rather than on particle release and reentry. Here we posit that MeV transfer from infected immune cells to epithelial cells also occurs by cell-to-cell contact rather than through cell-free particles. In

Dimethyl sulfoxide inactivates the anticancer effect of cisplatin against human myelogenous leukemia cell lines in in vitro assays

PubMed Central

Raghavan, Rahul; Cheriyamundath, Sanith; Madassery, Joseph

2015-01-01

Objectives: To investigate the effect of DMSO on cisplatin induced cytotoxicity (invitro) against K562 (Human mylogenous leukemia) cell line and to study the cisplatin-DMSO adduct formation using UV-spectrophotometer. Materials and methods: Effect of DMSO on the cytotoxicity of cisplatin was studied in K562 (Chronic mylogenous leukemia) cell line by MTT assay. Cisplatin-DMSO adduct formation was studied by continuously monitoring the increase in absorption peaks for 30 minutes using UV-spectrophotometer. Results: 0.1-0.3% DMSO markedly reduced the cytotoxic activity of cisplatin in K562 cells. Cisplatin-DMSO adduct formation was detected using UV-spectrophotometer. Continuous increase in UV absorbance between 250nm-290nm was observed when cisplatin (0.5mg/ml) and DMSO (10%) were mixed. Conclusion: Present study revealed that DMSO inactivates the cytotoxicity of cisplatin. Cisplatin-DMSO mixture showed increased absorbance at 250-290nm. Therefore, using DMSO in invitro assays might result in misinterpretation of actual efficacy of drugs. PMID:26069372

Dimethyl sulfoxide inactivates the anticancer effect of cisplatin against human myelogenous leukemia cell lines in in vitro assays.

PubMed

Raghavan, Rahul; Cheriyamundath, Sanith; Madassery, Joseph

2015-01-01

To investigate the effect of DMSO on cisplatin induced cytotoxicity (invitro) against K562 (Human mylogenous leukemia) cell line and to study the cisplatin-DMSO adduct formation using UV-spectrophotometer. Effect of DMSO on the cytotoxicity of cisplatin was studied in K562 (Chronic mylogenous leukemia) cell line by MTT assay. Cisplatin-DMSO adduct formation was studied by continuously monitoring the increase in absorption peaks for 30 minutes using UV-spectrophotometer. 0.1-0.3% DMSO markedly reduced the cytotoxic activity of cisplatin in K562 cells. Cisplatin-DMSO adduct formation was detected using UV-spectrophotometer. Continuous increase in UV absorbance between 250nm-290nm was observed when cisplatin (0.5mg/ml) and DMSO (10%) were mixed. Present study revealed that DMSO inactivates the cytotoxicity of cisplatin. Cisplatin-DMSO mixture showed increased absorbance at 250-290nm. Therefore, using DMSO in invitro assays might result in misinterpretation of actual efficacy of drugs.

Growth Factor-Activated Stem Cell Circuits and Stromal Signals Cooperatively Accelerate Non-Integrated iPSC Reprogramming of Human Myeloid Progenitors

PubMed Central

Park, Tea Soon; Huo, Jeffrey S.; Peters, Ann; Talbot, C. Conover; Verma, Karan; Zimmerlin, Ludovic; Kaplan, Ian M.; Zambidis, Elias T.

2012-01-01

Nonviral conversion of skin or blood cells into clinically useful human induced pluripotent stem cells (hiPSC) occurs in only rare fractions (∼0.001%–0.5%) of donor cells transfected with non-integrating reprogramming factors. Pluripotency induction of developmentally immature stem-progenitors is generally more efficient than differentiated somatic cell targets. However, the nature of augmented progenitor reprogramming remains obscure, and its potential has not been fully explored for improving the extremely slow pace of non-integrated reprogramming. Here, we report highly optimized four-factor reprogramming of lineage-committed cord blood (CB) myeloid progenitors with bulk efficiencies of ∼50% in purified episome-expressing cells. Lineage-committed CD33+CD45+CD34− myeloid cells and not primitive hematopoietic stem-progenitors were the main targets of a rapid and nearly complete non-integrated reprogramming. The efficient conversion of mature myeloid populations into NANOG+TRA-1-81+ hiPSC was mediated by synergies between hematopoietic growth factor (GF), stromal activation signals, and episomal Yamanaka factor expression. Using a modular bioinformatics approach, we demonstrated that efficient myeloid reprogramming correlated not to increased proliferation or endogenous Core factor expressions, but to poised expression of GF-activated transcriptional circuits that commonly regulate plasticity in both hematopoietic progenitors and embryonic stem cells (ESC). Factor-driven conversion of myeloid progenitors to a high-fidelity pluripotent state was further accelerated by soluble and contact-dependent stromal signals that included an implied and unexpected role for Toll receptor-NFκB signaling. These data provide a paradigm for understanding the augmented reprogramming capacity of somatic progenitors, and reveal that efficient induced pluripotency in other cell types may also require extrinsic activation of a molecular framework that commonly regulates self

Characteristics of Myeloid Differentiation and Maturation Pathway Derived from Human Hematopoietic Stem Cells Exposed to Different Linear Energy Transfer Radiation Types

PubMed Central

Monzen, Satoru; Yoshino, Hironori; Kasai-Eguchi, Kiyomi; Kashiwakura, Ikuo

2013-01-01

Exposure of hematopoietic stem/progenitor cells (HSPCs) to ionizing radiation causes a marked suppression of mature functional blood cell production in a linear energy transfer (LET)- and/or dose-dependent manner. However, little information about LET effects on the proliferation and differentiation of HSPCs has been reported. With the aim of characterizing the effects of different types of LET radiations on human myeloid hematopoiesis, in vitro hematopoiesis in Human CD34+ cells exposed to carbon-ion beams or X-rays was compared. Highly purified CD34+ cells exposed to each form of radiation were plated onto semi-solid culture for a myeloid progenitor assay. The surviving fractions of total myeloid progenitors, colony-forming cells (CFC), exposed to carbon-ion beams were significantly lower than of those exposed to X-rays, indicating that CFCs are more sensitive to carbon-ion beams (D 0 = 0.65) than to X-rays (D 0 = 1.07). Similar sensitivities were observed in granulocyte-macrophage and erythroid progenitors, respectively. However, the sensitivities of mixed-type progenitors to both radiation types were similar. In liquid culture for 14 days, no significant difference in total numbers of mononuclear cells was observed between non-irradiated control culture and cells exposed to 0.5 Gy X-rays, whereas 0.5 Gy carbon-ion beams suppressed cell proliferation to 4.9% of the control, a level similar to that for cells exposed to 1.5 Gy X-rays. Cell surface antigens associated with terminal maturation, such as CD13, CD14, and CD15, on harvest from the culture of X-ray-exposed cells were almost the same as those from the non-irradiated control culture. X-rays increased the CD235a+ erythroid-related fraction, whereas carbon-ion beams increased the CD34+CD38− primitive cell fraction and the CD13+CD14+/−CD15− fraction. These results suggest that carbon-ion beams inflict severe damage on the clonal growth of myeloid HSPCs, although the intensity of cell surface

Hoxa9 and Hoxa10 induce CML myeloid blast crisis development through activation of Myb expression.

PubMed

Negi, Vijay; Vishwakarma, Bandana A; Chu, Su; Oakley, Kevin; Han, Yufen; Bhatia, Ravi; Du, Yang

2017-11-17

Mechanisms underlying the progression of Chronic Myeloid Leukemia (CML) from chronic phase to myeloid blast crisis are poorly understood. Our previous studies have suggested that overexpression of SETBP1 can drive this progression by conferring unlimited self-renewal capability to granulocyte macrophage progenitors (GMPs). Here we show that overexpression of Hoxa9 or Hoxa10 , both transcriptional targets of Setbp1 , is also sufficient to induce self-renewal of primary myeloid progenitors, causing their immortalization in culture. More importantly, both are able to cooperate with BCR/ABL to consistently induce transformation of mouse GMPs and development of aggressive leukemias resembling CML myeloid blast crisis, suggesting that either gene can drive CML progression by promoting the self-renewal of GMPs. We further identify Myb as a common critical target for Hoxa9 and Hoxa10 in inducing self-renewal of myeloid progenitors as Myb knockdown significantly reduced colony-forming potential of myeloid progenitors immortalized by the expression of either gene. Interestingly, Myb is also capable of immortalizing primary myeloid progenitors in culture and cooperating with BCR/ABL to induce leukemic transformation of mouse GMPs. Significantly increased levels of MYB transcript also were detected in all human CML blast crisis samples examined over chronic phase samples, further suggesting the possibility that MYB overexpression may play a prevalent role in driving human CML myeloid blast crisis development. In summary, our results identify overexpression of HOXA9 , HOXA10 , and MYB as critical drivers of CML progression, and suggest MYB as a key therapeutic target for inhibiting the self-renewal of leukemia-initiating cells in CML myeloid blast crisis patients.

Antiproliferative Effects of Bacillus coagulans Unique IS2 in Colon Cancer Cells.

PubMed

Madempudi, Ratna Sudha; Kalle, Arunasree M

2017-10-01

In the present study, the in vitro anticancer (antiproliferative) effects of Bacillus coagulans Unique IS2 were evaluated on human colon cancer (COLO 205), cervical cancer (HeLa), and chronic myeloid leukemia (K562) cell lines with a human embryonic kidney cell line (HEK 293T) as noncancerous control cells. The Cytotoxicity assay (MTT) clearly demonstrated a 22%, 31.7%, and 19.5% decrease in cell proliferation of COLO 205, HeLa, and K562 cells, respectively, when compared to the noncancerous HEK 293T cells. Normal phase-contrast microscopic images clearly suggested that the mechanism of cell death is by apoptosis. To further confirm the induction of apoptosis by Unique IS2, the sub-G0-G1 peak of the cell cycle was quantified using a flow cytometer and the data indicated 40% of the apoptotic cells in Unique IS2-treated COLO cells when compared with their untreated control cells. The Western blot analysis showed an increase in pro-apoptotic protein BAX, decrease in antiapoptotic protein, Bcl2, decrease in mitochondrial membrane potential, increase in cytochrome c release, increase in Caspase 3 activity, and cleavage of poly(ADP-ribose) polymerase. The present study suggests that the heat-killed culture supernatant of B. coagulans can be more effective in inducing apoptosis of colon cancer cells and that can be considered for adjuvant therapy in the treatment of colon carcinoma.

[Cytotoxic effect of physalis peruviana in cell culture of colorectal and prostate cancer and chronic myeloid leukemia].

PubMed

Quispe-Mauricio, Angel; Callacondo, David; Rojas, José; Zavala, David; Posso, Margarita; Vaisberg, Abraham

2009-01-01

The plants have been used as drugs for centuries. However, limited research has been done on its great potential as sources of new therapeutic agents. The purpose of this study was to evaluate Physalis peruviana cytotoxic activity on cell lines HT-29, PC-3, K-562 and VERO. The HT-29 cell lines, PC-3, K-562 and VERO, were exposed to four concentrations of P. peruviana ethanolic leave and stem extracts, also at different concentrations of cisplatin and 5-fluorouracil (5-FU), which were used as positive controls. We found rates of growth within 48 hours, then we determined the inhibitory concentration 50 (IC50) using linear regression analysis and the index of selectivity of each sample. The P. peruviana ethanolic leave and stem extracts showed cytotoxic activity. The IC50 in g/mL in leaves and stems were, 0.35 (r =-0.95 p <0.025) and 0.37 (r =- 0.90 p <0.05 ) for HT-29; 0.87 (r =-0.98 p <0.01) and 1.01 (r =-0.95 p <0.025) for PC-3; 0.02 (r =-0.98 p <0.01) and 0.03 (r =-0.98 p <0.01) for K-562; 4.9 (r =-0.95 p <0.025) and 6.2 (r =-0.98 p <0.01) for VERO. The IC50 for antineoplastic were: for cisplatin: 4.2 (r =-0.96 p <0.025), 10.3 (r =-0.97 p <0.025), 0.15 (r =-0.98 p = 0.01) and 1.1 (r =- 0.98 p = 0.01); for 5-FU: 2.3 (r =-0.97 p <0.025), 17.9 (r =-0.95 p <0.025), 0.15 (r =-0.98 p = 0.01) and 1.1 (r =-0.94 p = 0.05) for HT-29, PC-3, K562 and VERO respectively. The leaves and stems extracts selectivity index were between 5.6 and 245 for tumor cell lines evaluated, by contrast, cisplatin and 5-FU, only showed values between 0.11 and 7.3. The P. peruviana leaves and steams ethanolic extracts were more cytotoxic than cisplatin and 5 FU, on the lines HT-29, PC-3 and K562. Furthermore the P. peruviana cytotoxic effects were less than cisplatin and 5-FU for VERO control cells lines.

How Is Chronic Myeloid Leukemia Diagnosed?

MedlinePlus

... Myeloid Leukemia? More In Chronic Myeloid Leukemia About Chronic Myeloid Leukemia Causes, Risk Factors, and Prevention Early Detection, Diagnosis, and Staging Treatment After Treatment Back To Top Imagine a world ...

Genetics Home Reference: chronic myeloid leukemia

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... Home Health Conditions Chronic myeloid leukemia Chronic myeloid leukemia Printable PDF Open All Close All Enable Javascript ... view the expand/collapse boxes. Description Chronic myeloid leukemia is a slow-growing cancer of the blood- ...

Antiproliferative Activity of Xanthones Isolated from Artocarpus obtusus

PubMed Central

Hashim, Najihah Mohd; Rahmani, Mawardi; Ee, Gwendoline Cheng Lian; Sukari, Mohd Aspollah; Yahayu, Maizatulakmal; Oktima, Winda; Ali, Abd Manaf; Go, Rusea

2012-01-01

An investigation of the chemical constituents in Artocarpus obtusus species led to the isolation of three new xanthones, pyranocycloartobiloxanthone A (1), dihydroartoindonesianin C (2), and pyranocycloartobiloxanthone B (3). The compounds were subjected to antiproliferative assay against human promyelocytic leukemia (HL60), human chronic myeloid leukemia (K562), and human estrogen receptor (ER+) positive breast cancer (MCF7) cell lines. Pyranocycloartobiloxanthone A (1) consistently showed strong cytotoxic activity against the three cell lines compared to the other two with IC50 values of 0.5, 2.0 and 5.0 μg/mL, respectively. Compound (1) was also observed to exert antiproliferative activity and apoptotic promoter towards HL60 and MCF7 cell lines at respective IC50 values. The compound (1) was not toxic towards normal cell lines human nontumorigenic breast cell line (MCF10A) and human peripheral blood mononuclear cells (PBMCs) with IC50 values of more than 30 μg/mL. PMID:21960741

Evaluation of Synergetic Anticancer Activity of Berberine and Curcumin on Different Models of A549, Hep-G2, MCF-7, Jurkat, and K562 Cell Lines.

PubMed

Balakrishna, Acharya; Kumar, M Hemanth

2015-01-01

Ayurvedic system of medicine is using Berberis aristata and Curcuma longa herbs to treat different diseases including cancer. The study was performed to evaluate the synergetic anticancer activity of Berberine and Curcumin by estimating the inhibition of the cell proliferation by cytotoxicity assay using MTT method on specified human cell lines (A549, Hep-G2, MCF-7, Jurkat, and K562). All the cells were harvested from the culture and seeded in the 96-well assay plates at seeding density of 2.0 × 10(4) cells/well and were incubated for 24 hours. Test items Berberine with Curcumin (1 : 1), Curcumin 95% pure, and Berberine 95% pure were exposed at the concentrations of 1.25, 0.001, and 0.5 mg/mL, respectively, and incubated for a period of 48 hours followed by dispensing MTT solution (5 mg/mL). The cells were incubated at 37 ± 1°C for 4 hours followed by addition of DMSO for dissolving the formazan crystals and absorbance was read at 570 nm. Separate wells were prepared for positive control, controls (only medium with cells), and blank (only medium). The results had proven the synergetic anticancer activity of Berberine with Curcumin inducing cell death greater percentage of >77% when compared to pure curcumin with <54% and pure Berberine with <45% on average on all cell line models.

Involvement of cell surface TG2 in the aggregation of K562 cells triggered by gluten.

PubMed

Feriotto, G; Calza, R; Bergamini, C M; Griffin, M; Wang, Z; Beninati, S; Ferretti, V; Marzola, E; Guerrini, R; Pagnoni, A; Cavazzini, A; Casciano, F; Mischiati, C

2017-03-01

Gluten-induced aggregation of K562 cells represents an in vitro model reproducing the early steps occurring in the small bowel of celiac patients exposed to gliadin. Despite the clear involvement of TG2 in the activation of the antigen-presenting cells, it is not yet clear in which compartment it occurs. Herein we study the calcium-dependent aggregation of these cells, using either cell-permeable or cell-impermeable TG2 inhibitors. Gluten induces efficient aggregation when calcium is absent in the extracellular environment, while TG2 inhibitors do not restore the full aggregating potential of gluten in the presence of calcium. These findings suggest that TG2 activity is not essential in the cellular aggregation mechanism. We demonstrate that gluten contacts the cells and provokes their aggregation through a mechanism involving the A-gliadin peptide 31-43. This peptide also activates the cell surface associated extracellular TG2 in the absence of calcium. Using a bioinformatics approach, we identify the possible docking sites of this peptide on the open and closed TG2 structures. Peptide docks with the closed TG2 structure near to the GTP/GDP site, by establishing molecular interactions with the same amino acids involved in stabilization of GTP binding. We suggest that it may occur through the displacement of GTP, switching the TG2 structure from the closed to the active open conformation. Furthermore, docking analysis shows peptide binding with the β-sandwich domain of the closed TG2 structure, suggesting that this region could be responsible for the different aggregating effects of gluten shown in the presence or absence of calcium. We deduce from these data a possible mechanism of action by which gluten makes contact with the cell surface, which could have possible implications in the celiac disease onset.

Phase 1 dose-finding study of rebastinib (DCC-2036) in patients with relapsed chronic myeloid leukemia and acute myeloid leukemia

PubMed Central

Cortes, Jorge; Talpaz, Moshe; Smith, Hedy P.; Snyder, David S.; Khoury, Jean; Bhalla, Kapil N.; Pinilla-Ibarz, Javier; Larson, Richard; Mitchell, David; Wise, Scott C.; Rutkoski, Thomas J.; Smith, Bryan D.; Flynn, Daniel L.; Kantarjian, Hagop M.; Rosen, Oliver; Van Etten, Richard A.

2017-01-01

A vailable tyrosine kinase inhibitors for chronic myeloid leukemia bind in an adenosine 5′-triphosphate-binding pocket and are affected by evolving mutations that confer resistance. Rebastinib was identified as a switch control inhibitor of BCR-ABL1 and FLT3 and may be active against resistant mutations. A Phase 1, first-in-human, single-agent study investigated rebastinib in relapsed or refractory chronic or acute myeloid leukemia. The primary objectives were to investigate the safety of rebastinib and establish the maximum tolerated dose and recommended Phase 2 dose. Fifty-seven patients received treatment with rebastinib. Sixteen patients were treated using powder-in-capsule preparations at doses from 57 mg to 1200 mg daily, and 41 received tablet preparations at doses of 100 mg to 400 mg daily. Dose-limiting toxicities were dysarthria, muscle weakness, and peripheral neuropathy. The maximum tolerated dose was 150 mg tablets administered twice daily. Rebastinib was rapidly absorbed. Bioavailability was 3- to 4-fold greater with formulated tablets compared to unformulated capsules. Eight complete hematologic responses were achieved in 40 evaluable chronic myeloid leukemia patients, 4 of which had a T315I mutation. None of the 5 patients with acute myeloid leukemia responded. Pharmacodynamic analysis showed inhibition of phosphorylation of substrates of BCR-ABL1 or FLT3 by rebastinib. Although clinical activity was observed, clinical benefit was insufficient to justify continued development in chronic or acute myeloid leukemia. Pharmacodynamic analyses suggest that other kinases inhibited by rebastinib, such as TIE2, may be more relevant targets for the clinical development of rebastinib (clinicaltrials.gov Identifier:00827138). PMID:27927766

Phase 1 dose-finding study of rebastinib (DCC-2036) in patients with relapsed chronic myeloid leukemia and acute myeloid leukemia.

PubMed

Cortes, Jorge; Talpaz, Moshe; Smith, Hedy P; Snyder, David S; Khoury, Jean; Bhalla, Kapil N; Pinilla-Ibarz, Javier; Larson, Richard; Mitchell, David; Wise, Scott C; Rutkoski, Thomas J; Smith, Bryan D; Flynn, Daniel L; Kantarjian, Hagop M; Rosen, Oliver; Van Etten, Richard A

2017-03-01

A vailable tyrosine kinase inhibitors for chronic myeloid leukemia bind in an adenosine 5'-triphosphate-binding pocket and are affected by evolving mutations that confer resistance. Rebastinib was identified as a switch control inhibitor of BCR-ABL1 and FLT3 and may be active against resistant mutations. A Phase 1, first-in-human, single-agent study investigated rebastinib in relapsed or refractory chronic or acute myeloid leukemia. The primary objectives were to investigate the safety of rebastinib and establish the maximum tolerated dose and recommended Phase 2 dose. Fifty-seven patients received treatment with rebastinib. Sixteen patients were treated using powder-in-capsule preparations at doses from 57 mg to 1200 mg daily, and 41 received tablet preparations at doses of 100 mg to 400 mg daily. Dose-limiting toxicities were dysarthria, muscle weakness, and peripheral neuropathy. The maximum tolerated dose was 150 mg tablets administered twice daily. Rebastinib was rapidly absorbed. Bioavailability was 3- to 4-fold greater with formulated tablets compared to unformulated capsules. Eight complete hematologic responses were achieved in 40 evaluable chronic myeloid leukemia patients, 4 of which had a T315I mutation. None of the 5 patients with acute myeloid leukemia responded. Pharmacodynamic analysis showed inhibition of phosphorylation of substrates of BCR-ABL1 or FLT3 by rebastinib. Although clinical activity was observed, clinical benefit was insufficient to justify continued development in chronic or acute myeloid leukemia. Pharmacodynamic analyses suggest that other kinases inhibited by rebastinib, such as TIE2, may be more relevant targets for the clinical development of rebastinib ( clinicaltrials.gov Identifier:00827138 ). Copyright© Ferrata Storti Foundation.

Influence of Hsp70 and HLA-E on the killing of leukemic blasts by cytokine/Hsp70 peptide-activated human natural killer (NK) cells.

PubMed

Stangl, Stefan; Gross, Catharina; Pockley, Alan G; Asea, Alexzander A; Multhoff, Gabriele

2008-01-01

This study compared the effects of the human 70-kDa stress protein (Hsp70) peptide, TKDNNLLGRFELSG (TKD), proinflammatory cytokines, or a combination of both on the repertoire of receptors expressed by human natural killer (NK) cells and their capacity to kill human CX colon carcinoma cells, K562 erythroleukemic cells, and leukemic blasts from two patients with acute myelogenous leukemia. Low-dose interleukin (IL) 2/IL-15 and TKD increase the expression density of activatory (NKG2D, NKp30, NKp44, NKp46, CD94/NKG2C) and inhibitory (CD94/NKG2A) receptors on NK cells. Concomitantly, IL-2/TKD treatment enhances the cytotoxicity of NK cells (as reflected by their secretion of granzyme B) against Hsp70 membrane-positive and human leukocyte antigen (HLA)-E membrane-negative (Hsp70(+)/HLA-E(-)) CX(+) and K562 cells. However, it had no effect on the responsiveness to Hsp70(-)/HLA-E(-) CX(-) cells over that induced by IL-2 alone. The cytotoxicity of IL-2/TKD-activated, purified NK cells and peripheral blood mononuclear cells against Hsp70(+)/HLA-E(+) leukemic blasts was weaker than that against Hsp70(+)/HLA-E(-) K562 cells. Hsp70-blocking and HLA-E transfection experiments confirmed membrane-bound Hsp70 as being a recognition/activatory ligand for NK cells, as cytotoxicity was reduced by the presence of the anti-Hsp70 monoclonal antibody cmHsp70.2 and by inhibiting Hsp70 synthesis using short interference ribonucleic acid. HLA-E was confirmed as an inhibitory ligand, as the extent of NK cell-mediated lysis of K562 cell populations that had been transfected with HLA-E(R) or HLA-E(G) alleles was dependent on the proportion of HLA-E-expressing cells. These findings indicate that Hsp70 (as an activatory molecule) and HLA-E (as an inhibitory ligand) expression influence the susceptibility of leukemic cells to the cytolytic activities of cytokine/TKD-activated NK cells.

Acute myeloid leukaemia diagnosed by intra-oral myeloid sarcoma. A case report.

PubMed

Papamanthos, Mattheos K; Kolokotronis, Alexandros E; Skulakis, Haralampos E; Fericean, Angela-Monika A; Zorba, Matina T; Matiakis, Apostolos T

2010-06-01

Myeloid sarcoma (MS) is a rare extramedullary malignant tumor composed of immature myeloid cells. It is strongly associated with a well known or covert acute myeloid leukaemia, chronic myeloproliferative diseases or myelodysplastic syndromes. Intraoral MS scarcely occurs. An unusual case of acute myeloid leukaemia, which was diagnosed by mandibular MS that was developed in the alveolar socket after a dental extraction, is reported. The histological examination (including immunohistochemical analysis) of a subsequent biopsy showed infiltration of the oral mucosa by neoplastic cells. This lesion was therefore classified as acute myeloid leukaemia. The patient was referred to oncologists that confirmed the initial diagnosis. The patient underwent chemotherapy and the mandibular tumor disappeared. Forty days later, a relapse of the disease, which appeared as a great-ulcerated lesion, was developed in the hard palate. Thirty days after the second chemotherapy had finished, a new intraoral tumor was developed in the vestibular maxillary gingiva. Review of the literature shows no report of intraoral relapse and particularly multiple relapse of a MS that involves the oral cavity. Even though MS is encountered infrequently in the oral cavity, it should be considered in the differential diagnosis of conditions (especially tumors) with a similar clinical appearance.

Acute Myeloid Leukaemia Diagnosed by Intra-Oral Myeloid Sarcoma. A Case Report

PubMed Central

Papamanthos, Mattheos K.; Skulakis, Haralampos E.; Fericean, Angela-Monika A.; Zorba, Matina T.; Matiakis, Apostolos T.

2010-01-01

Myeloid sarcoma (MS) is a rare extramedullary malignant tumor composed of immature myeloid cells. It is strongly associated with a well known or covert acute myeloid leukaemia, chronic myeloproliferative diseases or myelodysplastic syndromes. Intraoral MS scarcely occurs. An unusual case of acute myeloid leukaemia, which was diagnosed by mandibular MS that was developed in the alveolar socket after a dental extraction, is reported. The histological examination (including immunohistochemical analysis) of a subsequent biopsy showed infiltration of the oral mucosa by neoplastic cells. This lesion was therefore classified as acute myeloid leukaemia. The patient was referred to oncologists that confirmed the initial diagnosis. The patient underwent chemotherapy and the mandibular tumor disappeared. Forty days later, a relapse of the disease, which appeared as a great-ulcerated lesion, was developed in the hard palate. Thirty days after the second chemotherapy had finished, a new intraoral tumor was developed in the vestibular maxillary gingiva. Review of the literature shows no report of intraoral relapse and particularly multiple relapse of a MS that involves the oral cavity. Even though MS is encountered infrequently in the oral cavity, it should be considered in the differential diagnosis of conditions (especially tumors) with a similar clinical appearance. PMID:20512638

Phase I Trial of AZD1775 and Belinostat in Treating Patients With Relapsed or Refractory Myeloid Malignancies or Untreated Acute Myeloid Leukemia

ClinicalTrials.gov

2018-05-24

Acute Myeloid Leukemia; Blast Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Myelodysplastic Syndrome; Previously Treated Myelodysplastic Syndrome; Recurrent Adult Acute Myeloid Leukemia; Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Refractory Acute Myeloid Leukemia; Refractory Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Secondary Acute Myeloid Leukemia; Therapy-Related Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

[Clinical and Pathologic Features of Myeloid Sarcoma].

PubMed

Jiang, Ya-Jun; Wang, Hong-Xia; Zhuang, Wan-Chuan; Chen, Hao; Zhang, Chang; Li, Xiu-Mei; Zhu, Gui-Hua; He, Yao

2017-06-01

To explore the clinicopathologic features, differential diagnosis and therapy of myeloid sarcoma. The clinical data including clinical manifestations, laboratorial tests, histopathologicical examination, immunohistochemistry and clinical prognosis of 10 patients with myeloid sarcoma were analyzed retrospectively. Among 10 patients, 5 male and 5 female, aged 23 to 71 years old (median = 36 years). 2 cases of myeloid sarcoma were secondary from chronic myeloid leukemia, and 1 cases of myeloid sarcoma occurred after the allogeneic hematopoietic stem cell transplantation due to acute myeloid leukemia, and the others lacked the anamnesis of malignancies. The neoplasms occurred at bone, brain, skin, breast, epididymis, uterine cervix, small intestine, ovary and lymph nodes. Microscopically, the tumor cells were round or oval, which infiltrated diffusely or arranged in single-file. The cytoplasm was scarce and immature eosinophils were scattered. The nuclei were round, oval or focally irregular, and the mitosis was visible. The neoplasms were positive for MPO, CD34, CD43, CD45, CD99 and CD117 by immunohistochemical staining. 4 patients progressed into acute myeloid leukemia from 2 to 10 months after the diagnosis of myeloid sarcoma. All of them achieved complete remission after inductive chemotherapy, but 3 patients relapsed from 3 to 12 months after remission and only survived for 14 to 23 months. 4 patients were treated by using chemotherapy before bone marrow abnormality, and with the disease-free survival for 1 to 48 months. Myeloid sarcoma needs to be distinguished from lymphoblastic lymphoma, Burkitt's lymphoma, blastic plasmacytoid dendritic cell neoplasms and so on. The diagnosis and differential diagnosis of myeloid sarcoma are dependent on the pathological and immunohisto-chemical features. The chemotherapy and allogeneic hematopoietic stem cell transplantation of acute myeloid leukemia are the main methods for treatment of myeloid sarcoma.

Tipifarnib in Treating Older Patients With Acute Myeloid Leukemia

ClinicalTrials.gov

2015-03-19

Adult Acute Megakaryoblastic Leukemia; Adult Acute Monoblastic Leukemia; Adult Acute Monocytic Leukemia; Adult Acute Myeloid Leukemia With Inv(16)(p13.1q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With Maturation; Adult Acute Myeloid Leukemia With Minimal Differentiation; Adult Acute Myeloid Leukemia With t(16;16)(p13.1;q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); RUNX1-RUNX1T1; Adult Acute Myeloid Leukemia With t(9;11)(p22;q23); MLLT3-MLL; Adult Acute Myeloid Leukemia Without Maturation; Adult Acute Myelomonocytic Leukemia; Adult Erythroleukemia; Adult Pure Erythroid Leukemia; Alkylating Agent-Related Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Cytomegalovirus immune evasion of myeloid lineage cells.

PubMed

Brinkmann, Melanie M; Dağ, Franziska; Hengel, Hartmut; Messerle, Martin; Kalinke, Ulrich; Čičin-Šain, Luka

2015-06-01

Cytomegalovirus (CMV) evades the immune system in many different ways, allowing the virus to grow and its progeny to spread in the face of an adverse environment. Mounting evidence about the antiviral role of myeloid immune cells has prompted the research of CMV immune evasion mechanisms targeting these cells. Several cells of the myeloid lineage, such as monocytes, dendritic cells and macrophages, play a role in viral control, but are also permissive for CMV and are naturally infected by it. Therefore, CMV evasion of myeloid cells involves mechanisms that qualitatively differ from the evasion of non-CMV-permissive immune cells of the lymphoid lineage. The evasion of myeloid cells includes effects in cis, where the virus modulates the immune signaling pathways within the infected myeloid cell, and those in trans, where the virus affects somatic cells targeted by cytokines released from myeloid cells. This review presents an overview of CMV strategies to modulate and evade the antiviral activity of myeloid cells in cis and in trans.

Gastric myeloid sarcoma without acute myeloblastic leukemia

PubMed Central

Huang, Xiao-Li; Tao, Jin; Li, Jian-Zhong; Chen, Xiao-Liang; Chen, Jian-Ning; Shao, Chun-Kui; Wu, Bin

2015-01-01

Myeloid sarcomas (MS) involve extramedullary blast proliferation from one or more myeloid lineages that replace the original tissue architecture, and these neoplasias are called granulocytic sarcomas, chloromas or extramedullary myeloid tumors. Such tumors develop in lymphoid organs, bones (e.g., skulls and orbits), skin, soft tissue, various mucosae, organs, and the central nervous system. Gastrointestinal (GI) involvement is rare, while the occurrence of myeloid sarcomas in patients without leukemia is even rare. Here, we report a case of a 38-year-old man who presented with epigastric pain and progressive jaundice. An upper GI endoscopy had shown extensive multifocal hyperemic fold thickening and the spread of nodular lesions in the body of the stomach. Biopsies from the gastric lesions indicated myeloid sarcoma of the stomach. However, concurrent peripheral blood and bone marrow examinations showed no evidence of acute myeloid leukemia. For diagnosis, the immunohistochemical markers must be checked when evaluating a suspected myeloid sarcoma case. Accurate MS diagnosis determines the appropriate therapy and prognosis. PMID:25717265

State of the art in myeloid sarcoma.

PubMed

Klco, J M; Welch, J S; Nguyen, T T; Hurley, M Y; Kreisel, F H; Hassan, A; Lind, A C; Frater, J L

2011-12-01

Myeloid sarcomas are extramedullary lesions composed of myeloid lineage blasts that typically form tumorous masses and may precede, follow, or occur in the absence of systemic acute myeloid leukemia. They most commonly involve the skin and soft tissues, lymph nodes, and gastrointestinal tract and are particularly challenging to diagnose in patients without an antecedent history of acute myeloid leukemia. We conducted a search of the English language medical literature for recent studies of interest to individuals involved in the diagnosis of myeloid sarcoma. The differential diagnosis includes non-Hodgkin lymphoma, blastic plasmacytoid dendritic cell neoplasm, histiocytic sarcoma, melanoma, carcinoma, and (in children) small round blue cell tumors. The sensitivity and specificity of immunohistochemical markers must be considered when evaluating a suspected case of myeloid sarcoma. A high percentage of tested cases have cytogenetic abnormalities. A minimal panel of immunohistochemical markers should include anti-CD43 or anti-lysozyme as a lack of immunoreactivity for either of these sensitive markers would be inconsistent with a diagnosis of myeloid sarcoma. Use of more specific markers of myeloid disease, such as CD33, myeloperoxidase, CD34 and CD117 is necessary to establish the diagnosis. Other antibodies may be added depending on the differential diagnosis. Identification of acute myeloid leukemia-associated genetic lesions may be helpful in arriving at the correct diagnosis. © 2011 Blackwell Publishing Ltd.

MPL515 mutations in myeloproliferative and other myeloid disorders: a study of 1182 patients.

PubMed

Pardanani, Animesh D; Levine, Ross L; Lasho, Terra; Pikman, Yana; Mesa, Ruben A; Wadleigh, Martha; Steensma, David P; Elliott, Michelle A; Wolanskyj, Alexandra P; Hogan, William J; McClure, Rebecca F; Litzow, Mark R; Gilliland, D Gary; Tefferi, Ayalew

2006-11-15

Recently, a gain-of-function MPL mutation, MPLW515L, was described in patients with JAK2V617F-negative myelofibrosis with myeloid metaplasia (MMM). To gain more information on mutational frequency, disease specificity, and clinical correlates, genomic DNA from 1182 patients with myeloproliferative and other myeloid disorders and 64 healthy controls was screened for MPL515 mutations, regardless of JAK2V617F mutational status: 290 with MMM, 242 with polycythemia vera, 318 with essential thrombocythemia (ET), 88 with myelodysplastic syndrome, 118 with chronic myelomonocytic leukemia, and 126 with acute myeloid leukemia (AML). MPL515 mutations, either MPLW515L (n = 17) or a previously undescribed MPLW515K (n = 5), were detected in 20 patients. The diagnosis of patients with mutant MPL alleles at the time of molecular testing was de novo MMM in 12 patients, ET in 4, post-ET MMM in 1, and MMM in blast crisis in 3. Six patients carried the MPLW515L and JAK2V617F alleles concurrently. We conclude that MPLW515L or MPLW515K mutations are present in patients with MMM or ET at a frequency of approximately 5% and 1%, respectively, but are not observed in patients with polycythemia vera (PV) or other myeloid disorders. Furthermore, MPL mutations may occur concurrently with the JAK2V617F mutation, suggesting that these alleles may have functional complementation in myeloproliferative disease.

Blockade of Y177 and Nuclear Translocation of Bcr-Abl Inhibits Proliferation and Promotes Apoptosis in Chronic Myeloid Leukemia Cells.

PubMed

Li, Qianyin; Huang, Zhenglan; Gao, Miao; Cao, Weixi; Xiao, Qin; Luo, Hongwei; Feng, Wenli

2017-03-02

The gradual emerging of resistance to imatinib urgently calls for the development of new therapy for chronic myeloid leukemia (CML). The fusion protein Bcr-Abl, which promotes the malignant transformation of CML cells, is mainly located in the cytoplasm, while the c-Abl protein which is expressed in the nucleus can induce apoptosis. Based on the hetero-dimerization of FKBP (the 12-kDa FK506- and rapamycin-binding protein) and FRB (the FKBP-rapamycin binding domain of the protein kinase, mTOR) mediated by AP21967, we constructed a nuclear transport system to induce cytoplasmic Bcr-Abl into nuclear. In this study, we reported the construction of the nuclear transport system, and we demonstrated that FN3R (three nuclear localization signals were fused to FRBT2098L with a FLAG tag), HF2S (two FKBP domains were in tandem and fused to the SH2 domain of Grb2 with an HA tag) and Bcr-Abl form a complexus upon AP21967. Bcr-Abl was imported into the nucleus successfully by the nuclear transport system. The nuclear transport system inhibited CML cell proliferation through mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 5 (STAT5) pathways mainly by HF2S. It was proven that nuclear located Bcr-Abl induced CML cell (including imatinib-resistant K562G01 cells) apoptosis by activation of p73 and its downstream molecules. In summary, our study provides a new targeted therapy for the CML patients even with Tyrosine Kinase Inhibitor (TKI)-resistance.

Decitabine and Bortezomib in Treating Patients With Acute Myeloid Leukemia

ClinicalTrials.gov

2014-11-06

Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Myeloid cell differentiation arrest by miR-125b-1 in myelodysplasic syndrome and acute myeloid leukemia with the t(2;11)(p21;q23) translocation

PubMed Central

Bousquet, Marina; Quelen, Cathy; Rosati, Roberto; Mansat-De Mas, Véronique; La Starza, Roberta; Bastard, Christian; Lippert, Eric; Talmant, Pascaline; Lafage-Pochitaloff, Marina; Leroux, Dominique; Gervais, Carine; Viguié, Franck; Lai, Jean-Luc; Terre, Christine; Beverlo, Berna; Sambani, Costantina; Hagemeijer, Anne; Marynen, Peter; Delsol, Georges; Dastugue, Nicole; Mecucci, Cristina; Brousset, Pierre

2008-01-01

Most chromosomal translocations in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) involve oncogenes that are either up-regulated or form part of new chimeric genes. The t(2;11)(p21;q23) translocation has been cloned in 19 cases of MDS and AML. In addition to this, we have shown that this translocation is associated with a strong up-regulation of miR-125b (from 6- to 90-fold). In vitro experiments revealed that miR-125b was able to interfere with primary human CD34+ cell differentiation, and also inhibited terminal (monocytic and granulocytic) differentiation in HL60 and NB4 leukemic cell lines. Therefore, miR-125b up-regulation may represent a new mechanism of myeloid cell transformation, and myeloid neoplasms carrying the t(2;11) translocation define a new clinicopathological entity. PMID:18936236

Myeloid cell differentiation arrest by miR-125b-1 in myelodysplastic syndrome and acute myeloid leukemia with the t(2;11)(p21;q23) translocation.

PubMed

Bousquet, Marina; Quelen, Cathy; Rosati, Roberto; Mansat-De Mas, Véronique; La Starza, Roberta; Bastard, Christian; Lippert, Eric; Talmant, Pascaline; Lafage-Pochitaloff, Marina; Leroux, Dominique; Gervais, Carine; Viguié, Franck; Lai, Jean-Luc; Terre, Christine; Beverlo, Berna; Sambani, Costantina; Hagemeijer, Anne; Marynen, Peter; Delsol, Georges; Dastugue, Nicole; Mecucci, Cristina; Brousset, Pierre

2008-10-27

Most chromosomal translocations in myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) involve oncogenes that are either up-regulated or form part of new chimeric genes. The t(2;11)(p21;q23) translocation has been cloned in 19 cases of MDS and AML. In addition to this, we have shown that this translocation is associated with a strong up-regulation of miR-125b (from 6- to 90-fold). In vitro experiments revealed that miR-125b was able to interfere with primary human CD34(+) cell differentiation, and also inhibited terminal (monocytic and granulocytic) differentiation in HL60 and NB4 leukemic cell lines. Therefore, miR-125b up-regulation may represent a new mechanism of myeloid cell transformation, and myeloid neoplasms carrying the t(2;11) translocation define a new clinicopathological entity.

Decitabine in Treating Patients With Previously Untreated Acute Myeloid Leukemia

ClinicalTrials.gov

2016-05-18

Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Acute myeloid leukemia (AML) - children

MedlinePlus

Acute myeloid leukemia is a cancer of the blood and bone marrow. Bone marrow is the soft tissue inside ... develops quickly. Both adults and children can get acute myeloid leukemia ( AML ). This article is about AML in children.

Human hematopoietic progenitors express erythropoietin.

PubMed

Stopka, T; Zivny, J H; Stopkova, P; Prchal, J F; Prchal, J T

1998-05-15

Erythropoietin (EPO) is a factor essential for erythroid cell proliferation, differentiation, and survival. The production of EPO by the kidneys in response to hypoxia and anemia is well documented. To determine whether EPO is also produced by hematopoietic cells, we analyzed the expression of EPO in normal human hematopoietic progenitors and in their progeny. Undifferentiated CD34(+)lin- hematopoietic progenitors do not have detectable EPO mRNA. Differentiating CD34(+) cells that are stimulated with recombinant human EPO in serum-free liquid cultures express both EPO and EPO receptor (EPOR). Because CD34(+) cells represent a heterogeneous cell population, we analyzed individual burst-forming units-erythroid (BFU-E) and nonerythroid colony-forming unit-granulocyte-macrophage colonies for EPO mRNA. Only BFU-E colonies were positive for EPO mRNA. Lysates from pooled BFU-E colonies stained positively for EPO by immunoblotting. To further confirm the intrinsic nature of erythroid EPO, we replaced extrinsic EPO in erythroid colony cultures with EPO-mimicking peptide (EMP). We show EPO expression in the EMP-stimulated BFU-Es at both mRNA and protein levels. Stimulation of bone marrow mononuclear cells (BMMCs) with EMP upregulated EPO expression. Furthermore, we found EPO and EPOR mRNAs as well as EPO protein in K562 cells, a human erythroleukemia cell line. Stimulation of K562 cells with EMP upregulated EPO expression. We suggest that EPO of erythroid origin may have a role in the regulation of erythropoiesis.

Tipifarnib in Treating Patients With Acute Myeloid Leukemia in Remission

ClinicalTrials.gov

2018-03-20

Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Adult Acute Megakaryoblastic Leukemia; Adult Acute Monocytic Leukemia; Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With Inv(16)(p13.1q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With Maturation; Adult Acute Myeloid Leukemia With Minimal Differentiation; Adult Acute Myeloid Leukemia With t(16;16)(p13.1;q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With t(8;21); (q22; q22.1); RUNX1-RUNX1T1; Adult Acute Myeloid Leukemia With t(9;11)(p22.3;q23.3); MLLT3-KMT2A; Adult Acute Myeloid Leukemia Without Maturation; Adult Acute Myelomonocytic Leukemia; Adult Erythroleukemia; Adult Pure Erythroid Leukemia; Alkylating Agent-Related Acute Myeloid Leukemia; Myelodysplastic Syndrome With Excess Blasts; Recurrent Adult Acute Myeloid Leukemia

Structural Characteristics of the Novel Polysaccharide FVPA1 from Winter Culinary-Medicinal Mushroom, Flammulina velutipes (Agaricomycetes), Capable of Enhancing Natural Killer Cell Activity against K562 Tumor Cells.

PubMed

Jia, Wei; Feng, Jie; Zhang, Jing-Song; Lin, Chi-Chung; Wang, Wen-Han; Chen, Hong-Ge

2017-01-01

FVPA1, a novel polysaccharide, has been isolated from fruiting bodies of the culinary-medicinal mushroom Flammulina velutipes, a historically popular, widely cultivated and consumed functional food with an attractive taste, beneficial nutraceutical properties such as antitumor and immunomodulatory effects, and a number of essential biological activities. The average molecular weight was estimated to be ~1.8 × 104 Da based on high-performance size exclusion chromatography. Sugar analyses, methylation analyses, and 1H, 13C, and 2-dimensional nuclear magnetic resonance spectroscopy revealed the following structure of the repeating units of the FVPA1 polysaccharide Identification of this structure would conceivably lead to better understanding of the nutraceutical functions of this very important edible fungus. Bioactivity tests in vitro indicated that FVPA1 could significantly enhance natural killer cell activity against K562 tumor cells.

49 CFR 236.562 - Minimum rail current required.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Locomotives § 236.562 Minimum... continuous inductive automatic train stop or train control device to normal condition or to obtain a proceed...

49 CFR 236.562 - Minimum rail current required.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Rules and Instructions; Locomotives § 236.562 Minimum... continuous inductive automatic train stop or train control device to normal condition or to obtain a proceed...

BVR photometric investigation of galaxy pair KPG 562

NASA Astrophysics Data System (ADS)

Hendy, Y. H. M.

2018-06-01

This work presents BVR photometric observations and analyses for galaxy pair KPG 562 selected from the Karachentsev Catalog of Isolated Pairs of Galaxies. The observations were obtained using the 1.88-m Telescope of the Kottamia Astronomical Observatory (KAO), Egypt. There is no interaction signs assigned for this pair as reported by Karachentsev Catalog. We used the surface photometry technique to obtain photometric parameters for each galaxy of the pair. The isophotal contours, the luminosity profiles, color profiles (B-V, V-R), ellipticity profiles, position angle (PA) profiles and isophotal center-shift (xc, yc) profiles have been presented. The total and absolute magnitude, ellipticity and position angle (PA) were also obtained from the studied galaxy pair. The studied galaxy pair is clearly showing signs of interaction opposed to that found by Karachentsev. We found that the galaxy KPG 562b contains one tidal tail. The length and thickness of tidal tail were obtained and presented in this study.

JAK and MPL mutations in myeloid malignancies.

PubMed

Tefferi, Ayalew

2008-03-01

The Janus family of non-receptor tyrosine kinases (JAK1, JAK2, JAK3 and tyrosine kinase 2) transduces signals downstream of type I and II cytokine receptors via signal transducers and activators of transcription (STATs). JAK3 is important in lymphoid and JAK2 in myeloid cell proliferation and differentiation. The thrombopoietin receptor MPL is one of several JAK2 cognate receptors and is essential for myelopoiesis in general and megakaryopoiesis in particular. Germline loss-of-function (LOF) JAK3 and MPL mutations cause severe combined immunodeficiency and congenital amegakaryocytic thrombocytopenia, respectively. Germline gain-of-function (GOF) MPL mutation (MPLS505N) causes familial thrombocytosis. Somatic JAK3 (e.g. JAK3A572V, JAK3V722I, JAK3P132T) and fusion JAK2 (e.g. ETV6-JAK2, PCM1-JAK2, BCR-JAK2) mutations have respectively been described in acute megakaryocytic leukemia and acute leukemia/chronic myeloid malignancies. However, current attention is focused on JAK2 (e.g. JAK2V617F, JAK2 exon 12 mutations) and MPL (e.g. MPLW515L/K/S, MPLS505N) mutations associated with myeloproliferative neoplasms (MPNs). A JAK2 mutation, primarily JAK2V617F, is invariably associated with polycythemia vera (PV). The latter mutation also occurs in the majority of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). MPL mutational frequency in MPNs is substantially less (<10%). In general, despite a certain degree of genotype - phenotype correlations, the prognostic relevance of harbouring one of these mutations, or their allele burden when present, remains dubious. Regardless, based on the logical assumption that amplified JAK-STAT signalling is central to the pathogenesis of PV, ET and PMF, several anti-JAK2 tyrosine kinase inhibitors have been developed and are currently being tested in humans with these disorders.

AR-42 and Decitabine in Treating Patients With Acute Myeloid Leukemia

ClinicalTrials.gov

2018-03-12

Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Emerging therapeutic targets in human acute myeloid leukemia (part 2) - bromodomain inhibition should be considered as a possible strategy for various patient subsets.

PubMed

Reikvam, Håkon; Hoang, Tuyen Thi van; Bruserud, Øystein

2015-06-01

The recent advances in our understanding of leukemogenesis have clearly demonstrated that human acute myeloid leukemia is a heterogeneous malignancy, and several disease mechanisms should probably be regarded as possible therapeutic targets only for specific subsets of patients and not for acute myeloid leukemia in general. One promising strategy for epigenetic targeting is inhibition of the binding between bromodomain-containing transcription regulators and acetylated lysine residues on histones. This possible approach has been investigated especially for patients with 11q23 and chromosome 8 abnormalities. An alternative target is the histone methyltransferase COT1L. Major challenges for both approaches will be to clarify how these strategies should be combined with each other or with conventional chemotherapy, and whether their use should be limited to certain subsets of patients.

Modeling of Chronic Myeloid Leukemia: An Overview of In Vivo Murine and Human Xenograft Models

PubMed Central

Vellenga, Edo

2016-01-01

Over the past years, a wide variety of in vivo mouse models have been generated in order to unravel the molecular pathology of Chronic Myeloid Leukemia (CML) and to develop and improve therapeutic approaches. These models range from (conditional) transgenic models, knock-in models, and murine bone marrow retroviral transduction models followed by transplantation. With the advancement of immunodeficient xenograft models, it has become possible to use human stem/progenitor cells for in vivo studies as well as cells directly derived from CML patients. These models not only mimic CML but also have been instrumental in uncovering various fundamental mechanisms of CML disease progression and tyrosine kinase inhibitor (TKI) resistance. With the availability of iPSC technology, it has become feasible to derive, maintain, and expand CML subclones that are at least genetically identical to those in patients. The following review provides an overview of all murine as well as human xenograft models for CML established till date. PMID:27642303

Myricetin is a novel inhibitor of human inosine 5′-monophosphate dehydrogenase with anti-leukemia activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Huiling; Hu, Qian; Wang, Jingyuan

Human inosine 5′-monophosphate dehydrogenase (hIMPDH) is a rate-limiting enzyme in the de novo biosynthetic pathway of purine nucleotides, playing crucial roles in cellular proliferation, differentiation, and transformation. Dysregulation of hIMPDH expression and activity have been found in a variety of human cancers including leukemia. In this study, we found that myricetin, a naturally occurring phytochemical existed in berries, wine and tea, was a novel inhibitor of human type 1 and type 2 IMPDH (hIMPDH1/2) with IC{sub 50} values of 6.98 ± 0.22 μM and 4.10 ± 0.14 μM, respectively. Enzyme kinetic analysis using Lineweaver-Burk plot revealed that myricetin is a mix-type inhibitor for hIMPDH1/2. Differential scanningmore » fluorimetry and molecular docking simulation data demonstrate that myricetin is capable of binding with hIMPDH1/2. Myricetin treatment exerts potent anti-proliferative and pro-apoptotic effects on K562 human leukemia cells in a dose-dependent manner. Importantly, cytotoxicity of myricetin on K562 cells were markedly attenuated by exogenous addition of guanosine, a salvage pathway of maintaining intracellular pool of guanine nucleotides. Taking together, these results indicate that natural product myricetin exhibits potent anti-leukemia activity by interfering with purine nucleotides biosynthetic pathway through the suppression of hIMPDH1/2 catalytic activity. - Highlights: • Myricetin, a common dietary flavonoid, is a novel inhibitor of hIMPDH1/2. • Myricetin directly binds with hIMPDH1/2 and induces cell cycle arrest and apoptosis of leukemia cells. • The cytotoxicity of myricetin on K562 cells is markedly attenuated by exogenous addition of guanosine.« less

Myeloid Cell COX-2 deletion reduces mammary tumor growth through enhanced cytotoxic T-lymphocyte function

PubMed Central

Chen, Edward P.; Markosyan, Nune; Connolly, Emma; Lawson, John A.; Li, Xuanwen; Grant, Gregory R.; Grosser, Tilo; FitzGerald, Garret A.; Smyth, Emer M.

2014-01-01

Cyclooxygenase-2 (COX-2) expression is associated with poor prognosis across a range of human cancers, including breast cancer. The contribution of tumor cell-derived COX-2 to tumorigenesis has been examined in numerous studies; however, the role of stromal-derived COX-2 is ill-defined. Here, we examined how COX-2 in myeloid cells, an immune cell subset that includes macrophages, influences mammary tumor progression. In mice engineered to selectively lack myeloid cell COX-2 [myeloid-COX-2 knockout (KO) mice], spontaneous neu oncogene-induced tumor onset was delayed, tumor burden reduced, and tumor growth slowed compared with wild-type (WT). Similarly, growth of neu-transformed mammary tumor cells as orthotopic tumors in immune competent syngeneic myeloid-COX-2 KO host mice was reduced compared with WT. By flow cytometric analysis, orthotopic myeloid-COX-2 KO tumors had lower tumor-associated macrophage (TAM) infiltration consistent with impaired colony stimulating factor-1-dependent chemotaxis by COX-2 deficient macrophages in vitro. Further, in both spontaneous and orthotopic tumors, COX-2-deficient TAM displayed lower immunosuppressive M2 markers and this was coincident with less suppression of CD8+ cytotoxic T lymphocytes (CTLs) in myeloid-COX-2 KO tumors. These studies suggest that reduced tumor growth in myeloid-COX-2 KO mice resulted from disruption of M2-like TAM function, thereby enhancing T-cell survival and immune surveillance. Antibody-mediated depletion of CD8+, but not CD4+ cells, restored tumor growth in myeloid-COX-2 KO to WT levels, indicating that CD8+ CTLs are dominant antitumor effectors in myeloid-COX-2 KO mice. Our studies suggest that inhibition of myeloid cell COX-2 can potentiate CTL-mediated tumor cytotoxicity and may provide a novel therapeutic approach in breast cancer therapy. PMID:24590894

Cancer progression by reprogrammed BCAA metabolism in myeloid leukaemia.

PubMed

Hattori, Ayuna; Tsunoda, Makoto; Konuma, Takaaki; Kobayashi, Masayuki; Nagy, Tamas; Glushka, John; Tayyari, Fariba; McSkimming, Daniel; Kannan, Natarajan; Tojo, Arinobu; Edison, Arthur S; Ito, Takahiro

2017-05-25

Reprogrammed cellular metabolism is a common characteristic observed in various cancers. However, whether metabolic changes directly regulate cancer development and progression remains poorly understood. Here we show that BCAT1, a cytosolic aminotransferase for branched-chain amino acids (BCAAs), is aberrantly activated and functionally required for chronic myeloid leukaemia (CML) in humans and in mouse models of CML. BCAT1 is upregulated during progression of CML and promotes BCAA production in leukaemia cells by aminating the branched-chain keto acids. Blocking BCAT1 gene expression or enzymatic activity induces cellular differentiation and impairs the propagation of blast crisis CML both in vitro and in vivo. Stable-isotope tracer experiments combined with nuclear magnetic resonance-based metabolic analysis demonstrate the intracellular production of BCAAs by BCAT1. Direct supplementation with BCAAs ameliorates the defects caused by BCAT1 knockdown, indicating that BCAT1 exerts its oncogenic function through BCAA production in blast crisis CML cells. Importantly, BCAT1 expression not only is activated in human blast crisis CML and de novo acute myeloid leukaemia, but also predicts disease outcome in patients. As an upstream regulator of BCAT1 expression, we identified Musashi2 (MSI2), an oncogenic RNA binding protein that is required for blast crisis CML. MSI2 is physically associated with the BCAT1 transcript and positively regulates its protein expression in leukaemia. Taken together, this work reveals that altered BCAA metabolism activated through the MSI2-BCAT1 axis drives cancer progression in myeloid leukaemia.

Characterization of anti-leukemia components from Indigo naturalis using comprehensive two-dimensional K562/cell membrane chromatography and in silico target identification.

PubMed

Wu, Xunxun; Chen, Xiaofei; Dan, Jia; Cao, Yan; Gao, Shouhong; Guo, Zhiying; Zerbe, Philipp; Chai, Yifeng; Diao, Yong; Zhang, Lei

2016-05-06

Traditional Chinese Medicine (TCM) has been developed for thousands of years and has formed an integrated theoretical system based on a large amount of clinical practice. However, essential ingredients in TCM herbs have not been fully identified, and their precise mechanisms and targets are not elucidated. In this study, a new strategy combining comprehensive two-dimensional K562/cell membrane chromatographic system and in silico target identification was established to characterize active components from Indigo naturalis, a famous TCM herb that has been widely used for the treatment of leukemia in China, and their targets. Three active components, indirubin, tryptanthrin and isorhamnetin, were successfully characterized and their anti-leukemia effects were validated by cell viability and cell apoptosis assays. Isorhamnetin, with undefined cancer related targets, was selected for in silico target identification. Proto-oncogene tyrosine-protein kinase (Src) was identified as its membrane target and the dissociation constant (Kd) between Src and isorhamnetin was 3.81 μM. Furthermore, anti-leukemia effects of isorhamnetin were mediated by Src through inducing G2/M cell cycle arrest. The results demonstrated that the integrated strategy could efficiently characterize active components in TCM and their targets, which may bring a new light for a better understanding of the complex mechanism of herbal medicines.

Characterization of anti-leukemia components from Indigo naturalis using comprehensive two-dimensional K562/cell membrane chromatography and in silico target identification

PubMed Central

Wu, Xunxun; Chen, Xiaofei; Dan, Jia; Cao, Yan; Gao, Shouhong; Guo, Zhiying; Zerbe, Philipp; Chai, Yifeng; Diao, Yong; Zhang, Lei

2016-01-01

Traditional Chinese Medicine (TCM) has been developed for thousands of years and has formed an integrated theoretical system based on a large amount of clinical practice. However, essential ingredients in TCM herbs have not been fully identified, and their precise mechanisms and targets are not elucidated. In this study, a new strategy combining comprehensive two-dimensional K562/cell membrane chromatographic system and in silico target identification was established to characterize active components from Indigo naturalis, a famous TCM herb that has been widely used for the treatment of leukemia in China, and their targets. Three active components, indirubin, tryptanthrin and isorhamnetin, were successfully characterized and their anti-leukemia effects were validated by cell viability and cell apoptosis assays. Isorhamnetin, with undefined cancer related targets, was selected for in silico target identification. Proto-oncogene tyrosine-protein kinase (Src) was identified as its membrane target and the dissociation constant (Kd) between Src and isorhamnetin was 3.81 μM. Furthermore, anti-leukemia effects of isorhamnetin were mediated by Src through inducing G2/M cell cycle arrest. The results demonstrated that the integrated strategy could efficiently characterize active components in TCM and their targets, which may bring a new light for a better understanding of the complex mechanism of herbal medicines. PMID:27150638

14 CFR 27.562 - Emergency landing dynamic conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Emergency landing dynamic conditions. 27... Conditions § 27.562 Emergency landing dynamic conditions. (a) The rotorcraft, although it may be damaged in... must successfully complete dynamic tests or be demonstrated by rational analysis based on dynamic tests...

14 CFR 23.562 - Emergency landing dynamic conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Emergency Landing Conditions § 23.562 Emergency landing dynamic conditions. (a) Each seat/restraint system... dynamic tests conducted in accordance with paragraph (b) of this section: (1) The seat/restraint system... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Emergency landing dynamic conditions. 23...

Antitumor activity of ethanol extract from Hippophae rhamnoides L. leaves towards human acute myeloid leukemia cells in vitro.

PubMed

Zhamanbaeva, G T; Murzakhmetova, M K; Tuleukhanov, S T; Danilenko, M P

2014-12-01

We studied the effects of ethanol extract from Hippophae rhamnoides L. leaves on the growth and differentiation of human acute myeloid leukemia cells (KG-1a, HL60, and U937). The extract of Hippophae rhamnoides L. leaves inhibited cell growth depending on the cell strain and extract dose. In a high concentration (100 μg/ml), the extract also exhibited a cytotoxic effect on HL60 cells. Hippophae rhamnoides L. leaves extract did not affect cell differentiation and did not modify the differentiating effect of calcitriol, active vitamin D metabolite. Inhibition of cell proliferation was paralleled by paradoxical accumulation of phase S cells (synthetic phase) with a reciprocal decrease in the count of G1 cells (presynthetic phase). The extract in a concentration of 100 μg/ml induced the appearance of cells with a subdiploid DNA content (sub-G1 phase cells), which indicated induction of apoptosis. The antiproliferative effect of Hippophae rhamnoides L. extract on acute myeloid leukemia cells was at least partially determined by activation of the S phase checkpoint, which probably led to deceleration of the cell cycle and apoptosis induction.

Large-scale expansion of Vγ9Vδ2 T cells with engineered K562 feeder cells in G-Rex vessels and their use as chimeric antigen receptor-modified effector cells.

PubMed

Xiao, Lin; Chen, Can; Li, Zhendong; Zhu, Sumin; Tay, Johan Ck; Zhang, Xi; Zha, Shijun; Zeng, Jieming; Tan, Wee Kiat; Liu, Xin; Chng, Wee Joo; Wang, Shu

2018-03-01

Vγ9Vδ2 T cells are a minor subset of lymphocytes in the peripheral blood that has been extensively investigated for their tolerability, safety and anticancer efficacy. A hindrance to the broad application of these cells for adoptive cellular immunotherapy has been attaining clinically appropriate numbers of Vγ9Vδ2 T cells. Furthermore, Vγ9Vδ2 T cells exist at low frequencies among cancer patients. We, therefore, sought to conceive an economical method that allows for a quick and robust large-scale expansion of Vγ9Vδ2 T cells. A two-step protocol was developed, in which peripheral blood mononuclear cells (PBMCs) from healthy donors or cancer patients were activated with Zometa and interleukin (IL)-2, followed by co-culturing with gamma-irradiated, CD64-, CD86- and CD137L-expressing K562 artificial antigen-presenting cells (aAPCs) in the presence of the anti-CD3 antibody OKT3. We optimized the co-culture ratio of K562 aAPCs to immune cells, and migrated this method to a G-Rex cell growth platform to derive clinically relevant cell numbers in a Good Manufacturing Practice (GMP)-compliant manner. We further include a depletion step to selectively remove αβ T lymphocytes. The method exhibited high expansion folds and a specific enrichment of Vγ9Vδ2 T cells. Expanded Vγ9Vδ2 T cells displayed an effector memory phenotype with a concomitant down-regulated expression of inhibitory immune checkpoint receptors. Finally, we ascertained the cytotoxic activity of these expanded cells by using nonmodified and chimeric antigen receptor (CAR)-engrafted Vγ9Vδ2 T cells against a panel of solid tumor cells. Overall, we report an efficient approach to generate highly functional Vγ9Vδ2 T cells in massive numbers suitable for clinical application in an allogeneic setting. Copyright © 2018 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Cytophagic and S-100 protein immunoreactive myeloid leukemia cutis.

PubMed

Thomas, Crystal G; Patel, Rajiv M; Bergfeld, Wilma F

2010-03-01

Myeloid leukemia cutis (LC) is the cutaneous involvement by neoplastic leukocytes of the myeloid series. Myeloid LC may occur de novo or concurrently with acute myeloid leukemias, chronic myeloid leukemias, other myeloproliferative disorders or myelodysplastic syndromes. We describe an unusual case of cytophagic S-100 protein immunoreactive leukemia cutis presenting in an 87-year-old woman without prior history of myeloid leukemia or other hematologic disorders. We outline key histologic and immunohistochemical features that aide in the diagnosis of LC. The presence of cytophagocytosis on histologic examination, a phenomenon more commonly associated with lymphoid rather than myeloid malignancies, provided a clue to the possibility of a malignant process. The atypical myeloid infiltrate showed S-100 protein positivity, an unusual finding that may be seen in LC. Although not commonly reported in LC, the presence of S-100 protein positivity and cytophagocytosis should not lead to the premature exclusion of LC as a possible diagnosis until a thorough clinical, histologic and immunohistochemical evaluation is performed. In addition, the presence of cytophagocytosis has been shown to have prognostic significance for patients with myeloid leukemia.

14 CFR 25.562 - Emergency landing dynamic conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

....562 Emergency landing dynamic conditions. (a) The seat and restraint system in the airplane must be... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Emergency landing dynamic conditions. 25... successfully complete dynamic tests or be demonstrated by rational analysis based on dynamic tests of a similar...

14 CFR 29.562 - Emergency landing dynamic conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Emergency landing dynamic conditions. 29... Conditions § 29.562 Emergency landing dynamic conditions. (a) The rotorcraft, although it may be damaged in a... landing must successfully complete dynamic tests or be demonstrated by rational analysis based on dynamic...

Peroxisome Proliferator-Activated Receptor Ligands and Their Role in Chronic Myeloid Leukemia: Therapeutic Strategies.

PubMed

Yousefi, Bahman; Samadi, Nasser; Baradaran, Behzad; Shafiei-Irannejad, Vahid; Zarghami, Nosratollah

2016-07-01

Imatinib therapy remains the gold standard for treatment of chronic myeloid leukemia; however, the acquired resistance to this therapeutic agent in patients has urged the scientists to devise modalities for overcoming this chemoresistance. For this purpose, initially therapeutic agents with higher tyrosine kinase activity were introduced, which had the potential for inhibiting even mutant forms of Bcr-Abl. Furthermore, coupling imatinib with peroxisome proliferator-activated receptor ligands also showed beneficial effects in chronic myeloid leukemia cell proliferation. These combination protocols inhibited cell growth and induced apoptosis as well as differentiation in chronic myeloid leukemia cell lines. In addition, peroxisome proliferator-activated receptors ligands increased imatinib uptake by upregulating the expression of human organic cation transporter 1. Taken together, peroxisome proliferator-activated receptors ligands are currently being considered as novel promising therapeutic candidates for chronic myeloid leukemia treatment, because they can synergistically enhance the efficacy of imatinib. In this article, we reviewed the potential of peroxisome proliferator-activated receptors ligands for use in chronic myeloid leukemia treatment. The mechanism of action of these therapeutics modalities are also presented in detail. © 2016 John Wiley & Sons A/S.

Responses of the Murine Myeloid Colony-Forming Cell to Ansamycin Antibiotics

PubMed Central

Horoszewicz, Julius S.; Carter, William A.

1974-01-01

The in vitro susceptibility of murine myeloid colony-forming cells to the antiproliferative activities of three ansamycin antibiotics was determined. These cells were found to be 10- to 40-fold more susceptible than the corresponding human ones. PMID:4151701

Lenalidomide in Treating Older Patients With Acute Myeloid Leukemia

ClinicalTrials.gov

2014-07-25

Adult Acute Basophilic Leukemia; Adult Acute Eosinophilic Leukemia; Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

7 CFR 56.2 - Designation of official certificates, memoranda, marks, other identifications, and devices for...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Designation of official certificates, memoranda, marks, other identifications, and devices for purposes of the Agricultural Marketing Act. 56.2 Section 56.2 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices),...

Decitabine in Treating Patients With Myelodysplastic Syndromes or Acute Myeloid Leukemia

ClinicalTrials.gov

2013-09-27

Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; de Novo Myelodysplastic Syndromes; Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Secondary Myelodysplastic Syndromes; Untreated Adult Acute Myeloid Leukemia

Cytotoxic activity of vitamins K1, K2 and K3 against human oral tumor cell lines.

PubMed

Okayasu, H; Ishihara, M; Satoh, K; Sakagami, H

2001-01-01

Vitamin K1, K2 and K3 were compared for their cytotoxic activity, radical generation and O2- scavenging activity. Among these compounds, vitamin K3 showed the highest cytotoxic activity against human oral tumor cell lines (HSC-2, HSG), human promyelocytic leukemic cell line (HL-60) and human gingival fibroblast (HGF). Vitamin K3 induced internucleosomal DNA fragmentation in HL-60 cells, but not in HSC-2 or HSG cells. The cytotoxic activity of vitamins K2 and K1 was one and two orders lower, respectively, than K3. Vitamin K2, but not vitamin K3, showed tumor-specific cytotoxic action. ESR spectroscopy showed that only vitamin K3 produced radical(s) under alkaline condition and most potently enhanced the radical intensity of sodium ascorbate and scavenged O2- (generated by hypoxanthine-xanthine oxidase reaction system); vitamin K2 was much less active whereas vitamin K1 was inactive. These data suggest that the cytotoxic activity of vitamin K3 is generated by radical-mediated oxidation mechanism and that this vitamin has two opposing actions (that is, antioxidant and prooxidant), depending on the experimental conditions.

Tissue factor expression by myeloid cells contributes to protective immune response against Mycobacterium tuberculosis infection.

PubMed

Venkatasubramanian, Sambasivan; Tripathi, Deepak; Tucker, Torry; Paidipally, Padmaja; Cheekatla, Satyanarayana; Welch, Elwyn; Raghunath, Anjana; Jeffers, Ann; Tvinnereim, Amy R; Schechter, Melissa E; Andrade, Bruno B; Mackman, Nizel; Idell, Steven; Vankayalapati, Ramakrishna

2016-02-01

Tissue factor (TF) is a transmembrane glycoprotein that plays an essential role in hemostasis by activating coagulation. TF is also expressed by monocytes/macrophages as part of the innate immune response to infections. In the current study, we determined the role of TF expressed by myeloid cells during Mycobacterium tuberculosis (M. tb) infection by using mice lacking the TF gene in myeloid cells (TF(Δ) ) and human monocyte derived macrophages (MDMs). We found that during M. tb infection, a deficiency of TF in myeloid cells was associated with reduced inducible nitric oxide synthase (iNOS) expression, enhanced arginase 1 (Arg1) expression, enhanced IL-10 production and reduced apoptosis in infected macrophages, which augmented M. tb growth. Our results demonstrate that a deficiency of TF in myeloid cells promotes M2-like phenotype in M .tb infected macrophages. A deficiency in TF expression by myeloid cells was also associated with reduced fibrin deposition and increased matrix metalloproteases (MMP)-2 and MMP-9 mediated inflammation in M. tb infected lungs. Our studies demonstrate that TF expressed by myeloid cells has newly recognized abilities to polarize macrophages and to regulate M. tb growth. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Complete nucleotide sequence of the gene for human heparin cofactor II and mapping to chromosomal band 22q11

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herzog, R.; Lutz, S.; Blin, N.

1991-02-05

Heparin cofactor II (HCII) is a 66-kDa plasma glycoprotein that inhibits thrombin rapidly in the presence of dermatan sulfate or heparin. Clones comprising the entire HCII gene were isolated from a human leukocyte genomic library in EMBL-3 {lambda} phage. The sequence of the gene was determined on both strands of DNA (15,849 bp) and included 1,749 bp of 5{prime}-flanking sequence, five exons, four introns, and 476 bp of DNA 3{prime} to the polyadenylation site. Ten complete and one partial Alu repeats were identified in the introns and 5{prime}-flanking region. The HCII gene was regionally mapped on chromosome 22 using rodent-humanmore » somatic cell hybrids, carrying only parts of human chromosome 22, and the chronic myelogenous leukemia cell line K562. With the cDNA probe HCII7.2, containing the entire coding region of the gene, the HCII gene was shown to be amplified 10-20-fold in K562 cells by Southern analysis and in situ hybridization. From these data, the authors concluded that the HCII gene is localized on the chromosomal band 22q11 proximal to the breakpoint cluster region (BCR). Analysis by pulsed-field gel electrophoresis indicated that the amplified HCII gene in K562 cells maps at least 2 Mbp proximal to BCR-1. Furthermore, the HCII7.2 cDNA probe detected two frequent restriction fragment length polymorphisms with the restriction enzymes BamHI and Hind III.« less

Chemotherapy Plus Sargramostim in Treating Patients With Refractory Myeloid Cancer

ClinicalTrials.gov

2013-01-08

Accelerated Phase Chronic Myelogenous Leukemia; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Blastic Phase Chronic Myelogenous Leukemia; Chronic Myelomonocytic Leukemia; Chronic Phase Chronic Myelogenous Leukemia; Paroxysmal Nocturnal Hemoglobinuria; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Myeloid Leukemia; Refractory Anemia; Refractory Anemia With Ringed Sideroblasts; Relapsing Chronic Myelogenous Leukemia; Thrombocytopenia; Untreated Adult Acute Myeloid Leukemia

40 CFR 60.562-1 - Standards: Process emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Compound (VOC) Emissions from the Polymer Manufacturing Industry § 60.562-1 Standards: Process emissions... vent stream from a control device shall have car-sealed opened all valves in the vent system from the emission source to the control device and car-sealed closed all valves in vent system that would lead the...

Biodegradable charged polyester-based vectors (BCPVs) as an efficient non-viral transfection nanoagent for gene knockdown of the BCR-ABL hybrid oncogene in a human chronic myeloid leukemia cell line

NASA Astrophysics Data System (ADS)

Yang, Chengbin; Panwar, Nishtha; Wang, Yucheng; Zhang, Butian; Liu, Maixian; Toh, Huiting; Yoon, Ho Sup; Tjin, Swee Chuan; Chong, Peter Han Joo; Law, Wing-Cheung; Chen, Chih-Kuang; Yong, Ken-Tye

2016-04-01

First-line therapy of chronic myelogenous leukemia (CML) has always involved the use of BCR-ABL tyrosine-kinase inhibitors which is associated with an abnormal chromosome called Philadelphia chromosome. Although the overall survival rate has been improved by the current therapeutic regime, the presence of resistance has resulted in limited efficacy. In this study, an RNA interference (RNAi)-based therapeutic regime is proposed with the aim to knockdown the BCR-ABL hybrid oncogene using small interfering RNA (siRNA). The siRNA transfection rates have usually been limited due to the declining contact probability among polyplexes and the non-adherent nature of leukemic cells. Our work aims at addressing this limitation by using a biodegradable charged polyester-based vector (BCPV) as a nanocarrier for the delivery of BCR-ABL-specific siRNA to the suspension culture of a K562 CML cell line. BCR-ABL siRNAs were encapsulated in the BCPVs by electrostatic force. Cell internalization was facilitated by the BCPV and assessed by confocal microscopy and flow cytometry. The regulation of the BCR-ABL level in K562 cells as a result of RNAi was analyzed by real-time polymerase chain reaction (RT-PCR). We observed that BCPV was able to form stable nanoplexes with siRNA molecules, even in the presence of fetal bovine serum (FBS), and successfully assisted in vitro siRNA transfection in the non-adherent K562 cells. As a consequence of downregulation of BCR-ABL, BCPV-siRNA nanoplexes inhibited cell proliferation and promoted cell apoptosis. All results were compared with a commercial transfection reagent, Lipofectamine2000™, which served as a positive control. More importantly, this class of non-viral vector exhibits biodegradable features and negligible cytotoxicity, thus providing a versatile platform to deliver siRNA to non-adherent leukemia cells with high transfection efficiency by effectively overcoming extra- and intra-cellular barriers. Due to the excellent in vitro

A derivative of epigallocatechin-3-gallate induces apoptosis via SHP-1-mediated suppression of BCR-ABL and STAT3 signalling in chronic myelogenous leukaemia

PubMed Central

Jung, Ji Hoon; Yun, Miyong; Choo, Eun-Jeong; Kim, Sun-Hee; Jeong, Myoung-Seok; Jung, Deok-Beom; Lee, Hyemin; Kim, Eun-Ok; Kato, Nobuo; Kim, Bonglee; Srivastava, Sanjay K; Kaihatsu, Kunihiro; Kim, Sung-Hoon

2015-01-01

Background and Purpose Epigallocatechin-3-gallate (EGCG) is a component of green tea known to have chemo-preventative effects on several cancers. However, EGCG has limited clinical application, which necessitates the development of a more effective EGCG prodrug as an anticancer agent. Experimental Approach Derivatives of EGCG were evaluated for their stability and anti-tumour activity in human chronic myeloid leukaemia (CML) K562 and KBM5 cells. Key Results EGCG-mono-palmitate (EGCG-MP) showed most prolonged stability compared with other EGCG derivatives. EGCG-MP exerted greater cytotoxicity and apoptosis in K562 and KBM5 cells than the other EGCG derivatives. EGCG-MP induced Src-homology 2 domain-containing tyrosine phosphatase 1 (SHP-1) leading decreased oncogenic protein BCR-ABL and STAT3 phosphorylation in CML cells, compared with treatment with EGCG. Furthermore, EGCG-MP reduced phosphorylation of STAT3 and survival genes in K562 cells, compared with EGCG. Conversely, depletion of SHP-1 or application of the tyrosine phosphatase inhibitor pervanadate blocked the ability of EGCG-MP to suppress phosphorylation of BCR-ABL and STAT3, and the expression of survival genes downstream of STAT3. In addition, EGCG-MP treatment more effectively suppressed tumour growth in BALB/c athymic nude mice compared with untreated controls or EGCG treatment. Immunohistochemistry revealed increased caspase 3 and SHP-1 activity and decreased phosphorylation of BCR-ABL in the EGCG-MP-treated group relative to that in the EGCG-treated group. Conclusions and Implications EGCG-MP induced SHP-1-mediated inhibition of BCR-ABL and STAT3 signalling in vitro and in vivo more effectively than EGCG. This derivative may be a potent chemotherapeutic agent for CML treatment. PMID:25825203

In Vitro Characterization and Evaluation of the Cytotoxicity Effects of Nisin and Nisin-Loaded PLA-PEG-PLA Nanoparticles on Gastrointestinal (AGS and KYSE-30), Hepatic (HepG2) and Blood (K562) Cancer Cell Lines.

PubMed

Goudarzi, Fariba; Asadi, Asadollah; Afsharpour, Maryam; Jamadi, Robab Hassanvand

2018-05-01

The aim of this study was an in vitro evaluation and comparison of the cytotoxic effects of free nisin and nisin-loaded PLA-PEG-PLA nanoparticles on gastrointestinal (AGS and KYSE-30), hepatic (HepG2), and blood (K562) cancer cell lines. To create this novel anti-cancer drug delivery system, the nanoparticles were synthesized and then loaded with nisin. Subsequently, their biocompatibility, ability to enter cells, and physicochemical properties, including formation, size, and shape, were studied using hemolysis, fluorescein isothiocyanate (FITC), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM), respectively. Then, its loading efficiency and release kinetics were examined to assess the potential impact of this formulation for the nanoparticle carrier candidacy. The cytotoxicities of nisin and nisin-loaded nanoparticles were evaluated by using the MTT and Neutral Red (NR) uptake assays. Detections of the apoptotic cells were done via Ethidium Bromide (EB)/Acridine Orange (AO) staining. The FTIR spectra, SEM images, and DLS graph confirmed the formations of the nanoparticles and nisin-loaded nanoparticles with spherical, distinct, and smooth surfaces and average sizes of 100 and 200 nm, respectively. The loading efficiency of the latter nanoparticles was about 85-90%. The hemolysis test represented their non-cytotoxicities and the FITC images indicated their entrance inside the cells. An increase in the percentage of apoptotic cells was observed through EB/AO staining. These results demonstrated that nisin had a cytotoxic effect on AGS, KYSE-30, HepG2, and K562 cancer cell lines, while the cytotoxicity of nisin-loaded nanoparticles was more than that of the free nisin.

AZD1152, a novel and selective aurora B kinase inhibitor, induces growth arrest, apoptosis, and sensitization for tubulin depolymerizing agent or topoisomerase II inhibitor in human acute leukemia cells in vitro and in vivo.

PubMed

Yang, Jing; Ikezoe, Takayuki; Nishioka, Chie; Tasaka, Taizo; Taniguchi, Ayuko; Kuwayama, Yoshio; Komatsu, Naoki; Bandobashi, Kentaro; Togitani, Kazuto; Koeffler, H Phillip; Taguchi, Hirokuni; Yokoyama, Akihito

2007-09-15

Aurora kinases play an important role in chromosome alignment, segregation, and cytokinesis during mitosis. We have recently shown that hematopoietic malignant cells including those from acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) aberrantly expressed Aurora A and B kinases, and ZM447439, a potent inhibitor of Aurora kinases, effectively induced growth arrest and apoptosis of a variety of leukemia cells. The present study explored the effect of AZD1152, a highly selective inhibitor of Aurora B kinase, on various types of human leukemia cells. AZD1152 inhibited the proliferation of AML lines (HL-60, NB4, MOLM13), ALL line (PALL-2), biphenotypic leukemia (MV4-11), acute eosinophilic leukemia (EOL-1), and the blast crisis of chronic myeloid leukemia K562 cells with an IC50 ranging from 3 nM to 40 nM, as measured by thymidine uptake on day 2 of culture. These cells had 4N/8N DNA content followed by apoptosis, as measured by cell-cycle analysis and annexin V staining, respectively. Of note, AZD1152 synergistically enhanced the antiproliferative activity of vincristine, a tubulin depolymerizing agent, and daunorubicin, a topoisomerase II inhibitor, against the MOLM13 and PALL-2 cells in vitro. Furthermore, AZD1152 potentiated the action of vincristine and daunorubicin in a MOLM13 murine xenograft model. Taken together, AZD1152 is a promising new agent for treatment of individuals with leukemia. The combined administration of AZD1152 and conventional chemotherapeutic agent to patients with leukemia warrants further investigation.

Cutaneous myeloid sarcoma of the penile foreskin.

PubMed

Afrose, Ruquiya; Nebhnani, Deepa; Wadhwa, Neelam

2015-01-01

Myeloid sarcoma, considered to herald the onset of a blast crisis in the setting of chronic myeloproliferative neoplasm/dysplasia, typically presents during the course of the disorder. Cutaneous involvement is uncommon and lesions on genital skin are seldom seen. We present a case of a well-differentiated myeloid sarcoma in the penile foreskin in an apparently healthy 29-year-old male presenting with phimosis. The unusual composition of the inflammatory cell infiltrate, and characteristic sparing of dermal blood vessels, nerves and smooth muscle fibres led to the correct diagnosis. Absence of commonly observed changes in the circumcision skin like those of balanitis xerotica was also helpful. Detailed hematological work up revealed a previously undiagnosed chronic myeloid leukemia in chronic phase. The patient also had simultaneous priapism, another rare presentation of chronic myeloid leukemia. One year hence, the patient is in hematological remission with no evidence of extramedullary disease. Although priapism has been described as a rare presenting symptom in chronic myeloid leukemia, the present case is unique as this is the first time a cutaneous myeloid sarcoma has been documented in the penile foreskin.

Immunotherapy with myeloid cells for tolerance induction

PubMed Central

Rodriguez-García, Mercedes; Boros, Peter; Bromberg, Jonathan S.; Ochando, Jordi C.

2013-01-01

Purpose of review Understanding the interplay between myeloid dendritic cells and T cells under tolerogenic conditions, and whether their interactions induce the development of antigen-specific regulatory T cells (Tregs) is critical to uncover the mechanisms involved in the induction of indefinite allograft survival. Recent findings Myeloid dendritic cell–T-cell interactions are seminal events that determine the outcome of the immune response, and multiple in-vitro protocols suggest the generation of tolerogenic myeloid dendritic cells that modulate T-cell responses, and determine the outcome of the immune response to an allograft following adoptive transfer. We believe that identifying specific conditions that lead to the generation of tolerogenic myeloid dendritic cells and Tregs are critical for the manipulation the immune response towards the development of transplantation tolerance. Summary We summarize recent findings regarding specific culture conditions that generate tolerogenic myeloid dendritic cells that induce T-cell hyporesponsiveness and Treg development, and represents a novel immunotherapeutic approach to promote the induction of indefinite graft survival prolongation. The interpretations presented here illustrate that different mechanisms govern the generation tolerogenic myeloid dendritic cells, and we discuss the concomitant therapeutic implications. PMID:20616727

Abnormal RNA splicing and genomic instability after induction of DNMT3A mutations by CRISPR/Cas9 gene editing.

PubMed

Banaszak, Lauren G; Giudice, Valentina; Zhao, Xin; Wu, Zhijie; Gao, Shouguo; Hosokawa, Kohei; Keyvanfar, Keyvan; Townsley, Danielle M; Gutierrez-Rodrigues, Fernanda; Fernandez Ibanez, Maria Del Pilar; Kajigaya, Sachiko; Young, Neal S

2018-03-01

DNA methyltransferase 3A (DNMT3A) mediates de novo DNA methylation. Mutations in DNMT3A are associated with hematological malignancies, most frequently acute myeloid leukemia. DNMT3A mutations are hypothesized to establish a pre-leukemic state, rendering cells vulnerable to secondary oncogenic mutations and malignant transformation. However, the mechanisms by which DNMT3A mutations contribute to leukemogenesis are not well-defined. Here, we successfully created four DNMT3A-mutated K562 cell lines with frameshift mutations resulting in truncated DNMT3A proteins. DNMT3A-mutated cell lines exhibited significantly impaired growth and increased apoptotic activity compared to wild-type (WT) cells. Consistent with previous studies, DNMT3A-mutated cells displayed impaired differentiation capacity. RNA-seq was used to compare transcriptomes of DNMT3A-mutated and WT cells; DNMT3A ablation resulted in downregulation of genes involved in spliceosome function, causing dysfunction of RNA splicing. Unexpectedly, we observed DNMT3A-mutated cells to exhibit marked genomic instability and an impaired DNA damage response compared to WT. CRISPR/Cas9-mediated DNMT3A-mutated K562 cells may be used to model effects of DNMT3A mutations in human cells. Our findings implicate aberrant splicing and induction of genomic instability as potential mechanisms by which DNMT3A mutations might predispose to malignancy. Published by Elsevier Inc.

A large-scale RNA interference screen identifies genes that regulate autophagy at different stages.

PubMed

Guo, Sujuan; Pridham, Kevin J; Virbasius, Ching-Man; He, Bin; Zhang, Liqing; Varmark, Hanne; Green, Michael R; Sheng, Zhi

2018-02-12

Dysregulated autophagy is central to the pathogenesis and therapeutic development of cancer. However, how autophagy is regulated in cancer is not well understood and genes that modulate cancer autophagy are not fully defined. To gain more insights into autophagy regulation in cancer, we performed a large-scale RNA interference screen in K562 human chronic myeloid leukemia cells using monodansylcadaverine staining, an autophagy-detecting approach equivalent to immunoblotting of the autophagy marker LC3B or fluorescence microscopy of GFP-LC3B. By coupling monodansylcadaverine staining with fluorescence-activated cell sorting, we successfully isolated autophagic K562 cells where we identified 336 short hairpin RNAs. After candidate validation using Cyto-ID fluorescence spectrophotometry, LC3B immunoblotting, and quantitative RT-PCR, 82 genes were identified as autophagy-regulating genes. 20 genes have been reported previously and the remaining 62 candidates are novel autophagy mediators. Bioinformatic analyses revealed that most candidate genes were involved in molecular pathways regulating autophagy, rather than directly participating in the autophagy process. Further autophagy flux assays revealed that 57 autophagy-regulating genes suppressed autophagy initiation, whereas 21 candidates promoted autophagy maturation. Our RNA interference screen identifies identified genes that regulate autophagy at different stages, which helps decode autophagy regulation in cancer and offers novel avenues to develop autophagy-related therapies for cancer.

Mpl traffics to the cell surface through conventional and unconventional routes

PubMed Central

Cleyrat, Cédric; Darehshouri, Anza; Steinkamp, Mara P.; Vilaine, Mathias; Boassa, Daniela; Ellisman, Mark H.; Hermouet, Sylvie; Wilson, Bridget S.

2014-01-01

Myeloproliferative neoplasms (MPNs) are often characterized by JAK2 or calreticulin mutations, indicating aberrant trafficking in pathogenesis. This study focuses on Mpl trafficking and Jak2 association using two model systems: Human Erythroleukemia cells (HEL; JAK2V617F) and K562 myeloid leukemia cells (JAK2WT). Consistent with a putative chaperone role for Jak2, Mpl and Jak2 associate on both intracellular and plasma membranes (shown by proximity ligation assay) and siRNA-mediated knockdown of Jak2 led to Mpl trapping in the ER. Even in Jak2 sufficient cells, Mpl accumulates in punctate structures that partially co-localize with ER-Tracker, the ER exit site marker (ERES) Sec31a, the autophagy marker LC3 and LAMP1. Mpl was fused to miniSOG, a genetically-encoded tag for correlated light and electron microscopy. Results suggest that a fraction of Mpl is taken up into autophagic structures from the ER and routed to autolyososomes. Surface biotinylation shows that both immature and mature Mpl reach the cell surface; in K562 cells Mpl is also released in exosomes. Both forms rapidly internalize upon ligand addition, while recovery is primarily attributed to immature Mpl. Mpl appears to reach the plasma membrane via both conventional ER-Golgi and autolysosome secretory pathways, as well as recycling. PMID:24931576

CT-721, a Potent Bcr-Abl Inhibitor, Exhibits Excellent In Vitro and In Vivo Efficacy in the Treatment of Chronic Myeloid Leukemia

PubMed Central

Sun, Yinghui; Zhao, Na; Wang, Huan; Wu, Qiong; Han, Yunqi; Liu, Qichao; Wu, Mangang; Liu, Yuliang; Kong, Fansheng; Wang, He; Sun, Ying; Sun, Deguang; Jing, Lutao; Tang, Guojing; Hu, Yuandong; Xiao, Dengming; Luo, Hong; Han, Yongxin; Peng, Yong

2017-01-01

Kinase inhibitors that target Bcr-Abl are highly effective in the treatment of chronic myeloid leukemia (CML). However, these inhibitors are often invalidated due to the drug resistance. Therefore, the discovery and development of novel Bcr-Abl inhibitors is required to overwhelm the drug resistance in the treatment of CML resistant to the currently used first-line Bcr-Abl inhibitors. Herein we have described a newly developed Bcr-Abl inhibitor CT-721, which displayed potent inhibitory effects on wild-type and T315I mutant Bcr-Abl. It functioned as a typically ATP-competitive inhibitor, superior to other existing Bcr-Abl inhibitors. CT-721 also demonstrated time-dependent inhibition of Bcr-Abl activation and the resultant downstream signaling transduction pathways in Bcr-Abl positive cells. Furthermore, CT-721 induced cell apoptosis and cell cycle arrest, and efficaciously inhibited tumor growth in Bcr-Abl-expressed K562 and KU812 xenograft models in a mechanism-based manner. Further PK/PD studies revealed a positive in vivo correlation between the compound concentration and inhibition of Bcr-Abl activity. Taken together, CT-721 is a potent and time-dependent Bcr-Abl kinase inhibitor, and has shown strong in vitro and in vivo anti-CML activities with a favorable pharmacokinetic profile, differentiating it from other Bcr-Abl kinase inhibitors already approved and current in development for the treatment of CML. PMID:28928866

Loss of the tumor suppressor p15Ink4b enhances myeloid progenitor formation from common myeloid progenitors.

PubMed

Rosu-Myles, Michael; Taylor, Barbara J; Wolff, Linda

2007-03-01

The tumor suppressor p15Ink4b (Ink4b) is a cell-cycle inhibitor that is inactivated in a high percentage of acute myeloid leukemia and myeloid dysplasia syndrome cases. Despite this, the role of Ink4b in hematopoiesis remains unclear. Here we examined the role of Ink4b in blood cell formation using Ink4b-deficient (Ink4b(-/-)) mice. We compared the bone marrow (BM) of Ink4b(-/-) and wild-type mice using flow cytometric, colony-forming unit and competitive repopulating assays (CRA). The proliferation, differentiation, self-renewal, and apoptosis of progenitor cells were further compared by in vitro and in vivo methods. BM from Ink4b(-/-) mice contained increased numbers of granulocyte-monocyte progenitors and Gr-1(+) cells and showed a competitive advantage over wild-type cells in myeloid cell formation by CRA. Ink4b(-/-) progenitors did not demonstrate increased proliferation, self-renewing potential, or reduced apoptosis. Instead, Ink4b(-/-) common myeloid progenitors (CMPs) showed increased myeloid progenitor formation concomitant with reduced erythroid potential. This work establishes a role for Ink4b in regulating the differentiation of CMPs and indicates that loss of Ink4b enhances the formation of myeloid progenitors.

Closure Report for Corrective Action Unit 562: Waste Systems, Nevada National Security Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

NSTec Environmental Restoration

2012-08-15

This Closure Report (CR) presents information supporting closure of Corrective Action Unit (CAU) 562, Waste Systems, and provides documentation supporting the completed corrective actions and confirmation that closure objectives for CAU 562 were met. This CR complies with the requirements of the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the State of Nevada; the U.S. Department of Energy (DOE), Environmental Management; the U.S. Department of Defense; and DOE, Legacy Management (FFACO, 1996 as amended). CAU 562 consists of the following 13 Corrective Action Sites (CASs), located in Areas 2, 23, and 25 of the Nevadamore » National Security Site: · CAS 02-26-11, Lead Shot · CAS 02-44-02, Paint Spills and French Drain · CAS 02-59-01, Septic System · CAS 02-60-01, Concrete Drain · CAS 02-60-02, French Drain · CAS 02-60-03, Steam Cleaning Drain · CAS 02-60-04, French Drain · CAS 02-60-05, French Drain · CAS 02-60-06, French Drain · CAS 02-60-07, French Drain · CAS 23-60-01, Mud Trap Drain and Outfall · CAS 23-99-06, Grease Trap · CAS 25-60-04, Building 3123 Outfalls Closure activities began in October 2011 and were completed in April 2012. Activities were conducted according to the Corrective Action Plan for CAU 562 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2011). The corrective actions included No Further Action and Clean Closure. Closure activities generated sanitary waste and hazardous waste. Some wastes exceeded land disposal limits and required offsite treatment prior to disposal. Other wastes met land disposal restrictions and were disposed in appropriate onsite or offsite landfills. NNSA/NSO requests the following: · A Notice of Completion from the Nevada Division of Environmental Protection to NNSA/NSO for closure of CAU 562 · The transfer of CAU 562 from Appendix III to Appendix IV, Closed Corrective Action Units, of the FFACO« less

Genital ulcers as diagnostic clue for acute myeloid leukaemia.

PubMed

Schröder, Sina D; Krause, Stefan W; Erfurt-Berge, Cornelia

2018-04-23

Acute myeloid leukaemia is a myeloid neoplasm with an extremely varying clinical appearance. Skin lesions are common for specific subtypes of acute myeloid leukaemia but are often misinterpreted. Here, we present a case of acute myeloid leukaemia in a young woman exhibiting genital ulcerations and gingival erosions. © 2018 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Vosaroxin and Infusional Cytarabine in Treating Patients With Untreated Acute Myeloid Leukemia

ClinicalTrials.gov

2017-06-27

Acute Myeloid Leukemia; Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Acute Myeloid Leukemia With Multilineage Dysplasia; Myeloid Sarcoma; Secondary Acute Myeloid Leukemia; Therapy-Related Acute Myeloid Leukemia; Therapy-Related Myelodysplastic Syndrome

Expression of checkpoint molecules on myeloid-derived suppressor cells.

PubMed

Ballbach, Marlene; Dannert, Angelika; Singh, Anurag; Siegmund, Darina M; Handgretinger, Rupert; Piali, Luca; Rieber, Nikolaus; Hartl, Dominik

2017-12-01

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous cell population expanded in cancer, infection and autoimmunity capable of suppressing T-cell functions. Checkpoint inhibitors have emerged as a key therapeutic strategy in immune-oncology. While checkpoint molecules were initially associated with T cell functions, recent evidence suggests a broader expression and function in innate myeloid cells. Previous studies provided first evidence for a potential role for checkpoints on MDSCs, yet the human relevance remained poorly understood. Therefore, we investigated the expression and functional relevance of checkpoint molecules in human MDSC-T-cell interactions. Our studies demonstrate that programmed death-ligand 1 (PD-L1) is expressed on granulocytic MDSCs upon co-culture with T cells. Transwell experiments showed that cell-to-cell contact was required for MDSC-T-cell interactions and antibody blocking studies showed that targeting PD-L1 partially impaired MDSC-mediated T-cell suppression. Collectively, these studies suggest a role for PD-L1 in human MDSC function and thereby expand the functionality of this checkpoint beyond T cells, which could pave the way for further understanding and therapeutic targeting of PD-1/PD-L1 in innate immune-mediated diseases. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Curcumin induces apoptosis in human leukemic cell lines through an IFIT2-dependent pathway

PubMed Central

Zhang, Yonglu; Kong, Yunyuan; Liu, Shuyuan; Zeng, Lingbing; Wan, Lagen; Zhang, Zhanglin

2017-01-01

ABSTRACT Curcumin, the primary bioactive component isolated from turmeric, has been shown to possess variety of biologic functions including anti-cancer activity. However, molecular mechanisms in different cancer cells are various. In the present study, we demonstrated that curcumin induced G2/M cell cycle arrest and apoptosis by increasing the expression levels of cleaved caspase-3, cleaved PARP and decreasing the expression of BCL−2 in U937 human leukemic cells but not in K562 cells. We found some interferon induced genes, especially interferon-induced protein with tetratricopeptide repeats 2 (IFIT2), were significantly upregulated when treated with curcumin in U937 cells by gene expression chip array, and further confirmed that the expression of IFIT2 was obviously higher in U937 than that in K562 cells by Western blot assay. In addition, inhibiting the expression of IFIT2 by shRNA in U937 rescued curcumin-induced apoptosis and exogenous overexpression of IFIT2 by lentiviral transduction or treating with IFNγ in K562 cells enhanced anti-cancer activity of curcumin. These results indicated for the first time that curcumin induced leukemic cell apoptosis via an IFIT2-dependent signaling pathways. The present study identified a novel mechanism underlying the antitumor effects of curcumin, and may provide a theoretical basis for curcumin combined with interferon in the cancer therapeutics. PMID:28071969

KLF6 contributes to myeloid cell plasticity in the pathogenesis of intestinal inflammation

PubMed Central

Goodman, Wendy A.; Omenetti, Sara; Date, Dipali; Di Martino, Luca; De Salvo, Carlo; Kim, Gun-Dong; Chowdhry, Saleem; Bamias, Giorgos; Cominelli, Fabio; Pizarro, Theresa T.; Mahabeleshwar, Ganapati H.

2016-01-01

Inflammatory bowel disease (IBD) is associated with dysregulated macrophage responses, such that quiescent macrophages acquire a pro-inflammatory activation state and contribute to chronic intestinal inflammation. The transcriptional events governing macrophage activation and gene expression in the context of chronic inflammation such as IBD remain incompletely understood. Here, we identify Kruppel-like transcription factor-6 (KLF6) as a critical regulator of pathogenic myeloid cell activation in human and experimental IBD. We found that KLF6 was significantly upregulated in myeloid cells and intestinal tissue from IBD patients and experimental models of IBD, particularly in actively inflamed regions of the colon. Using complementary gain- and loss-of-function studies, we observed that KLF6 promotes pro-inflammatory gene expression through enhancement of NFκB signaling, while simultaneously suppressing anti-inflammatory gene expression through repression of STAT3 signaling. To study the in vivo role of myeloid KLF6, we treated myeloid-specific KLF6-knockout mice (Mac-KLF6-KO) with dextran sulfate-sodium (DSS) and found that Mac-KLF6-KO mice were protected against chemically-induced colitis; this highlights the central role of myeloid KLF6 in promoting intestinal inflammation. Collectively, our results point to a novel gene regulatory program underlying pathogenic, pro-inflammatory macrophage activation in the setting of chronic intestinal inflammation. PMID:26838049

Expansion of NK cells by engineered K562 cells co-expressing 4-1BBL and mMICA, combined with soluble IL-21.

PubMed

Jiang, Bo; Wu, Xuan; Li, Xi-Ning; Yang, Xi; Zhou, Yulai; Yan, Haowei; Wei, An-Hui; Yan, Weiqun

2014-07-01

NK cells hold promise for protecting hosts from cancer and pathogen infection through direct killing and expressing immune-regulatory cytokines. In our study, a genetically modified K562 cell line with surface expression of 4-1BBL and MICA was constructed to expand functional NK cells in vitro for further adoptive immunotherapy against cancer. After a long-term up to 21 day co-culture with newly isolated peripheral blood mononuclear cells (PBMCs) in the presence of soluble IL-21 (sIL-21), notable increase in proportion of expanded NK cells was observed, especially the CD56(bright)CD16(+) subset. Apparent up-regulation of activating receptors CD38, CD69 and NKG2D was detected on expanded NK cells, so did inhibitory receptor CD94; the cytotoxicity of expanded NK cells against target tumor cells exceeded that of NK cells within fresh PBMCs. The intracellular staining showed expanded NK cells produced immune-regulatory IFN-γ. Taken together, we expanded NK cells with significant up-regulation of activating NKG2D and moderate enhancement of cytotoxicity, with IFN-γ producing ability and a more heterogeneous population of NK cells. These findings provide a novel perspective on expanding NK cells in vitro for further biology study and adoptive immunotherapy of NK cells against cancer. Copyright © 2014 Elsevier Inc. All rights reserved.

Spontaneous mediastinal myeloid sarcoma in a common marmoset (Callithrix jacchus) and review of the veterinary literature

PubMed Central

Morosco, Danielle T.; Cline, Curtis R.; Owston, Michael A.; Kumar, Shyamesh; Dick, Edward J.

2017-01-01

Background Myeloid sarcoma is a rare manifestation of myeloproliferative disorder defined as an extramedullary mass composed of myeloid precursor cells. A 9-month old, female, common marmoset (Callithrix jacchus) had increased respiratory effort. Methods A complete necropsy with histology and immunohistochemistry was performed. Results The thymus was replaced by a firm, grey-tan mass with a faint green tint, filling over 50% of the thoracic cavity. Sheets of granulocytes, lymphoid cells, nucleated erythrocytes, megakaryocytes, and hematopoietic precursors of indeterminate cell lineage replaced the thymus, perithymic connective tissue, mediastinal adipose tissues, epicardium, and much of the myocardium. The cells demonstrated diffuse strong cytoplasmic immunoreactivity for lysozyme, and strong, multifocal membranous immunoreactivity for CD117. Conclusion We report the first case of a myeloid sarcoma in a common marmoset (Callithrix jacchus), similar to reported human cases of mediastinal myeloid sarcoma, and present a review of myeloproliferative diseases from the veterinary literature. PMID:28145579

A defective retroviral vector encoding human interferon-alpha2 can transduce human leukemic cell lines.

PubMed

Austruy, E; Bagnis, C; Carbuccia, N; Maroc, C; Birg, F; Dubreuil, P; Mannoni, P; Chabannon, C

1998-01-01

Using the LXSN backbone, a defective retroviral vector (LISN) was constructed that encodes the human interferon (IFN)-alpha2 (hIFN-alpha2) gene and the neomycin resistance gene; the hIFN-alpha2 gene was cloned from human placental genomic DNA. High titers of the LISN retrovirus were produced by the amphotropic packaging cell line GP+envAM12. LISN is able to infect three human hematopoietic and leukemic cell lines: K562, LAMA-84, and TF-1. G418-resistant cells were detected in a similar proportion after infection with either the LISN retroviral vector or the LnLSN retroviral vector (encoding the nlsLacZ gene instead of hIFN-alpha2), suggesting that hIFN-alpha2 does not inhibit (or only partially inhibits) the production of retroviral particles by the packaging cell line and the infection of human cells. LISN-infected cells express and secrete hIFN-alpha2 as demonstrated by Northern blot analysis of poly(A)+ RNA, detection of the intracellular protein by fluorescence-activated cell sorter analysis, and detection of secreted hIFN-alpha in cell supernatants using an enzyme-linked immunosorbent assay. Retrovirally produced hIFN-alpha2 is biologically active, as demonstrated by the partial inhibition of the growth of K562 and TF-1, the modulation of the expression of cell surface antigens, the induction of the (2'-5') oligoadenylate synthetase, and, for LAMA-84, the down-modulation of the BCR-ABL protein. We conclude that the infection of human leukemic cell lines with a retroviral vector encoding hIFN-alpha2 is feasible and induces the expected biological effects. This experimental model will be useful in investigating the possibility of transducing normal and leukemic cells and hematopoietic progenitors and in determining the consequences of the autocrine production of hIFN-alpha2 on the behavior of these cells.

In vivo self-bio-imaging of tumors through in situ biosynthesized fluorescent gold nanoclusters

NASA Astrophysics Data System (ADS)

Wang, Jianling; Zhang, Gen; Li, Qiwei; Jiang, Hui; Liu, Chongyang; Amatore, Christian; Wang, Xuemei

2013-01-01

Fluorescence imaging in vivo allows non-invasive tumor diagnostic thus permitting a direct monitoring of cancer therapies progresses. It is established herein that fluorescent gold nanoclusters are spontaneously biosynthesized by cancerous cell (i.e., HepG2, human hepatocarcinoma cell line; K562, leukemia cell line) incubated with micromolar chloroauric acid solutions, a biocompatible molecular Au(III) species. Gold nanoparticles form by Au(III) reduction inside cells cytoplasms and ultimately concentrate around their nucleoli, thus affording precise cell imaging. Importantly, this does not occur in non-cancerous cells, as evidenced with human embryo liver cells (L02) used as controls. This dichotomy is exploited for a new strategy for in vivo self-bio-imaging of tumors. Subcutaneous injections of millimolar chloroauric acid solution near xenograft tumors of the nude mouse model of hepatocellular carcinoma or chronic myeloid leukemia led to efficient biosynthesis of fluorescent gold nanoclusters without significant dissemination to the surrounding normal tissues, hence allowing specific fluorescent self-bio-marking of the tumors.

Aid is a key regulator of myeloid/erythroid differentiation and DNA methylation in hematopoietic stem/progenitor cells

PubMed Central

Kunimoto, Hiroyoshi; McKenney, Anna Sophia; Meydan, Cem; Shank, Kaitlyn; Nazir, Abbas; Rapaport, Franck; Durham, Benjamin; Garrett-Bakelman, Francine E.; Pronier, Elodie; Shih, Alan H.; Melnick, Ari; Chaudhuri, Jayanta

2017-01-01

Recent studies have reported that activation-induced cytidine deaminase (AID) and ten-eleven-translocation (TET) family members regulate active DNA demethylation. Genetic alterations of TET2 occur in myeloid malignancies, and hematopoietic-specific loss of Tet2 induces aberrant hematopoietic stem cell (HSC) self-renewal/differentiation, implicating TET2 as a master regulator of normal and malignant hematopoiesis. Despite the functional link between AID and TET in epigenetic gene regulation, the role of AID loss in hematopoiesis and myeloid transformation remains to be investigated. Here, we show that Aid loss in mice leads to expansion of myeloid cells and reduced erythroid progenitors resulting in anemia, with dysregulated expression of Cebpa and Gata1, myeloid/erythroid lineage-specific transcription factors. Consistent with data in the murine context, silencing of AID in human bone marrow cells skews differentiation toward myelomonocytic lineage. However, in contrast to Tet2 loss, Aid loss does not contribute to enhanced HSC self-renewal or cooperate with Flt3-ITD to induce myeloid transformation. Genome-wide transcription and differential methylation analysis uncover the critical role of Aid as a key epigenetic regulator. These results indicate that AID and TET2 share common effects on myeloid and erythroid lineage differentiation, however, their role is nonredundant in regulating HSC self-renewal and in myeloid transformation. PMID:28077417

40 CFR 180.562 - Flucarbazone-sodium; tolerances for residues.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Flucarbazone-sodium; tolerances for... § 180.562 Flucarbazone-sodium; tolerances for residues. (a) General. Tolerances are established for combined residues of the herbicide flucarbazone-sodium, 4,5-dihydro-3-methoxy-4-methyl-5-oxo-N-[[2...

Acute myeloid leukaemia: a paradigm for the clonal evolution of cancer?

PubMed Central

Grove, Carolyn S.; Vassiliou, George S.

2014-01-01

Acute myeloid leukaemia (AML) is an uncontrolled clonal proliferation of abnormal myeloid progenitor cells in the bone marrow and blood. Advances in cancer genomics have revealed the spectrum of somatic mutations that give rise to human AML and drawn our attention to its molecular evolution and clonal architecture. It is now evident that most AML genomes harbour small numbers of mutations, which are acquired in a stepwise manner. This characteristic, combined with our ability to identify mutations in individual leukaemic cells and our detailed understanding of normal human and murine haematopoiesis, makes AML an excellent model for understanding the principles of cancer evolution. Furthermore, a better understanding of how AML evolves can help us devise strategies to improve the therapy and prognosis of AML patients. Here, we draw from recent advances in genomics, clinical studies and experimental models to describe the current knowledge of the clonal evolution of AML and its implications for the biology and treatment of leukaemias and other cancers. PMID:25056697

Decitabine, Cytarabine, and Daunorubicin Hydrochloride in Treating Patients With Acute Myeloid Leukemia

ClinicalTrials.gov

2018-05-24

Acute Myeloid Leukemia; Adult Acute Basophilic Leukemia; Adult Acute Monoblastic Leukemia; Adult Acute Monocytic Leukemia; Adult Acute Myeloid Leukemia With Maturation; Adult Acute Myeloid Leukemia With t(9;11)(p22.3;q23.3); MLLT3-KMT2A; Adult Acute Myeloid Leukemia Without Maturation; Adult Acute Myelomonocytic Leukemia; Alkylating Agent-Related Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

CIP-36, a novel topoisomerase II-targeting agent, induces the apoptosis of multidrug-resistant cancer cells in vitro.

PubMed

Cao, Bo; Chen, Hong; Gao, Ying; Niu, Cong; Zhang, Yuan; Li, Ling

2015-03-01

The need to overcome cancer multidrug resistance (MDR) has fueled considerable interest in the development of novel synthetic antitumor agents with cytotoxicity against cancer cell lines with MDR. In this study, we aimed to investigate CIP-36, a novel podophyllotoxin derivative, for its inhibitory effects on human cancer cells from multiple sources, particularly cells with MDR in vitro. The human leukemia cell line, K562, and the adriamycin-resistant subline, K562/A02, were exposed to CIP-36 or anticancer agents, and various morphological and biochemical properties were assessed by Hoechst 33342 staining under a fluorescence microscope. Subsequently, cytotoxicity, cell growth curves and the cell cycle were analyzed. Finally, the effects of CIP-36 on topoisomerase IIα (Topo IIα) activity were determined. Treatment with CIP-36 significantly inhibited the growth of the K562 and MDR K562/A02 cells. Our data demonstrated that CIP-36 induced apoptosis, inhibited cell cycle progression and inhibited Topo IIα activity. These findings suggest that CIP-36 has the potential to overcome the multidrug resistance of K562/A02 cells by mediating Topo IIα activity.

Omacetaxine Mepesuccinate for Chronic Myeloid Leukemia.

PubMed

Rosshandler, Yasmin; Shen, Ann Q; Cortes, Jorge; Khoury, Hanna Jean

2016-05-01

Omacetaxine mepesuccinate is approved by the Food and Drug Administration in the United States for the treatment of chronic myeloid leukemia in chronic or accelerated phase resistant to two or more tyrosine kinase inhibitors. This review summarizes the mode of action, pharmacokinetics, efficacy and safety of omacetaxine mepesuccinate. Omacetaxine mepesuccinate has activity in chronic myeloid leukemia, especially in the chronic phase, regardless of the presence of ABL1 kinase domain mutations. Omacetaxine mepesuccinate has distinct but manageable adverse events profile. Omacetaxine mepesuccinate is a treatment option for a subset of patients with refractory chronic myeloid leukemia.

Stage-Specific Human Induced Pluripotent Stem Cells Map the Progression of Myeloid Transformation to Transplantable Leukemia.

PubMed

Kotini, Andriana G; Chang, Chan-Jung; Chow, Arthur; Yuan, Han; Ho, Tzu-Chieh; Wang, Tiansu; Vora, Shailee; Solovyov, Alexander; Husser, Chrystel; Olszewska, Malgorzata; Teruya-Feldstein, Julie; Perumal, Deepak; Klimek, Virginia M; Spyridonidis, Alexandros; Rampal, Raajit K; Silverman, Lewis; Reddy, E Premkumar; Papaemmanuil, Elli; Parekh, Samir; Greenbaum, Benjamin D; Leslie, Christina S; Kharas, Michael G; Papapetrou, Eirini P

2017-03-02

Myeloid malignancy is increasingly viewed as a disease spectrum, comprising hematopoietic disorders that extend across a phenotypic continuum ranging from clonal hematopoiesis to myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). In this study, we derived a collection of induced pluripotent stem cell (iPSC) lines capturing a range of disease stages encompassing preleukemia, low-risk MDS, high-risk MDS, and secondary AML. Upon their differentiation, we found hematopoietic phenotypes of graded severity and/or stage specificity that together delineate a phenotypic roadmap of disease progression culminating in serially transplantable leukemia. We also show that disease stage transitions, both reversal and progression, can be modeled in this system using genetic correction or introduction of mutations via CRISPR/Cas9 and that this iPSC-based approach can be used to uncover disease-stage-specific responses to drugs. Our study therefore provides insight into the cellular events demarcating the initiation and progression of myeloid transformation and a new platform for testing genetic and pharmacological interventions. Copyright © 2017 Elsevier Inc. All rights reserved.

Heterogeneity of Clonal Expansion and Maturation-Linked Mutation Acquisition in Hematopoietic Progenitors in Human Acute Myeloid Leukemia

PubMed Central

Walter, Roland B.; Laszlo, George S.; Lionberger, Jack M.; Pollard, Jessica A.; Harrington, Kimberly H.; Gudgeon, Chelsea J.; Othus, Megan; Rafii, Shahin; Meshinchi, Soheil; Appelbaum, Frederick R.; Bernstein, Irwin D.

2014-01-01

Recent technological advances led to an appreciation of the genetic complexity of human acute myeloid leukemia (AML) but underlying progenitor cells remain poorly understood because their rarity precludes direct study. We developed a co-culture method integrating hypoxia, aryl hydrocarbon receptor inhibition, and micro-environmental support via human endothelial cells to isolate these cells. X-chromosome inactivation studies of the least mature precursors derived following prolonged culture of CD34+/CD33− cells revealed polyclonal growth in highly curable AMLs, suggesting mutations necessary for clonal expansion were acquired in more mature progenitors. Consistently, in core-binding factor (CBF) leukemias with known complementing mutations, immature precursors derived following prolonged culture of CD34+/CD33− cells harbored neither mutation or the CBF mutation alone, whereas more mature precursors often carried both mutations. These results were in contrast to those with leukemias with poor prognosis that showed clonal dominance in the least mature precursors. These data indicate heterogeneity among progenitors in human AML that may have prognostic and therapeutic implications. PMID:24721792

Glucose-6-phosphate transporter gene therapy corrects metabolic and myeloid abnormalities in glycogen storage disease type Ib mice

PubMed Central

Yiu, Wai Han; Pan, Chi-Jiunn; Allamarvdasht, Mohammad; Kim, So Youn; Chou, Janice Y.

2008-01-01

Glycogen storage disease type Ib (GSD-Ib) is caused by a deficiency in the glucose-6-phosphate transporter (G6PT), an endoplasmic reticulum-associated transmembrane protein that is ubiquitously expressed. GSD-Ib patients suffer from disturbed glucose homeostasis and myeloid dysfunctions. To evaluate the feasibility of gene replacement therapy for GSD-Ib, we have infused adenoviral (Ad) vector containing human G6PT (Ad-hG6PT) into G6PT-deficient (G6PT-/-) mice that manifest symptoms characteristics of the human disorder. Ad-hG6PT-infusion restores significant levels of G6PT mRNA expression in the liver, bone marrow, and spleen and corrects metabolic as well as myeloid abnormalities in G6PT-/- mice. The G6PT-/- mice receiving gene therapy exhibit improved growth; normalized serum profiles for glucose, cholesterol, triglyceride, uric acid, and lactic acid; and reduced hepatic glycogen deposition. The therapy also corrects neutropenia and lowers the elevated serum levels of granulocyte colony stimulating factor. The development of bone and spleen in the infused G6PT-/- mice is improved and accompanied by increased cellularity and normalized myeloid progenitor cell frequencies in both tissues. This effective use of gene therapy to correct metabolic imbalances and myeloid dysfunctions in GSD-Ib mice holds promise for the future of gene therapy in humans. PMID:17006547

Therapeutic Antibodies for Myeloid Neoplasms—Current Developments and Future Directions

PubMed Central

Schürch, Christian M.

2018-01-01

Therapeutic monoclonal antibodies (mAbs) such as antibody–drug conjugates, ligand–receptor antagonists, immune checkpoint inhibitors and bispecific T cell engagers have shown impressive efficacy in the treatment of multiple human cancers. Numerous therapeutic mAbs that have been developed for myeloid neoplasms, including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), are currently investigated in clinical trials. Because AML and MDS originate from malignantly transformed hematopoietic stem/progenitor cells—the so-called leukemic stem cells (LSCs) that are highly resistant to most standard drugs—these malignancies frequently relapse and have a high disease-specific mortality. Therefore, combining standard chemotherapy with antileukemic mAbs that specifically target malignant blasts and particularly LSCs or utilizing mAbs that reinforce antileukemic host immunity holds great promise for improving patient outcomes. This review provides an overview of therapeutic mAbs for AML and MDS. Antibody targets, the molecular mechanisms of action, the efficacy in preclinical leukemia models, and the results of clinical trials are discussed. New developments and future studies of therapeutic mAbs in myeloid neoplasms will advance our understanding of the immunobiology of these diseases and enhance current therapeutic strategies. PMID:29868474

Resveratrol-induced transcriptional up-regulation of ASMase (SMPD1) of human leukemia and cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mizutani, Naoki; College of Life and Health Sciences, Chubu University, Kasugai; Omori, Yukari

2016-02-19

Resveratrol (RSV) is a plant-derived phytoalexin present in plants, whose pleiotropic effects for health benefits have been previously reported. Its anti-cancer activity is among the current topics for novel cancer treatment. Here, effects of RSV on cell proliferation and the sphingolipid metabolism of K562, a human leukemia cell line, were analyzed. Some experiments were also performed in HCT116, a human colon cancer cell line. RSV inhibited cell proliferation of both cell lines. Increased cellular ceramide and decreased sphingomyelin and S1P by RSV were observed in RSV-treated K562 cells. Further analysis revealed that acid sphingomyelinase mRNA and enzyme activity levels were increasedmore » by RSV. Desipramine, a functional ASMase inhibitor, prevented RSV-induced ceramide increase. RSV increased ATF3, EGR1, EGR3 proteins and phosphorylated c-Jun and FOXO3. However, co-transfection using these transcription factor expression vectors and ASMase promoter reporter vector revealed positive effects of EGR1 and EGR3 but not others. Electrophoresis mobility shift assay (EMSA) and Chromatin immunoprecipitation (ChIP) assay demonstrated the direct binding of EGR1/3 transcription factors with ASMase 5′-promoter. These results indicate that increased EGR1/3 and ASMase expression play an important role in cellular ceramide increase by RSV treatment. - Highlights: • Resveratrol inhibited cell proliferation of K562 and HCT116 cells. • Resveratrol increased cellular ceramide and decreased sphingomyelin and S1P. • ASMase mRNA and activity were increased with resveratrol. • ASMase inhibition suppressed RSV-induced ceramide accumulation. • Increased ASMase transcription was at least partially due to EGR family proteins.« less

Tipifarnib in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

ClinicalTrials.gov

2013-02-01

Acute Myeloid Leukemia With Multilineage Dysplasia Following Myelodysplastic Syndrome; Adult Acute Erythroid Leukemia (M6); Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monoblastic Leukemia and Acute Monocytic Leukemia (M5); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Recurrent Adult Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Dasatinib, Cytarabine, and Idarubicin in Treating Patients With High-Risk Acute Myeloid Leukemia

ClinicalTrials.gov

2018-05-04

Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Hierarchical maintenance of MLL myeloid leukemia stem cells employs a transcriptional program shared with embryonic rather than adult stem cells

PubMed Central

Somervaille, Tim C. P.; Matheny, Christina J.; Spencer, Gary J.; Iwasaki, Masayuki; Rinn, John L.; Witten, Daniela M.; Chang, Howard Y.; Shurtleff, Sheila A.; Downing, James R.; Cleary, Michael L.

2009-01-01

Summary The genetic programs that promote retention of self-renewing leukemia stem cells (LSCs) at the apex of cellular hierarchies in acute myeloid leukemia (AML) are not known. In a mouse model of human AML, LSCs exhibit variable frequencies that correlate with the initiating MLL oncogene and are maintained in a self-renewing state by a transcriptional sub-program more akin to that of embryonic stem cells (ESCs) than adult stem cells. The transcription/chromatin regulatory factors Myb, Hmgb3 and Cbx5 are critical components of the program and suffice for Hoxa/Meis-independent immortalization of myeloid progenitors when co-expressed, establishing the cooperative and essential role of an ESC-like LSC maintenance program ancillary to the leukemia initiating MLL/Hox/Meis program. Enriched expression of LSC maintenance and ESC-like program genes in normal myeloid progenitors and poor prognosis human malignancies links the frequency of aberrantly self-renewing progenitor-like cancer stem cells to prognosis in human cancer. PMID:19200802

Combination Chemotherapy and Dasatinib in Treating Patients With Newly Diagnosed Acute Myeloid Leukemia

ClinicalTrials.gov

2018-05-24

Acute Myeloid Leukemia; Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Adult Acute Myeloid Leukemia With Inv(16)(p13.1q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With t(16;16)(p13.1;q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With t(8;21); (q22; q22.1); RUNX1-RUNX1T1; Core Binding Factor Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Therapy-Related Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Sorafenib Tosylate and Chemotherapy in Treating Older Patients With Acute Myeloid Leukemia

ClinicalTrials.gov

2018-06-01

Acute Myeloid Leukemia; Acute Myeloid Leukemia (Megakaryoblastic) With t(1;22)(p13.3;q13.3); RBM15-MKL1; Acute Myeloid Leukemia With a Variant RARA Translocation; Acute Myeloid Leukemia With Inv(3) (q21.3;q26.2) or t(3;3) (q21.3;q26.2); GATA2, MECOM; Acute Myeloid Leukemia With t(6;9) (p23;q34.1); DEK-NUP214; Acute Myeloid Leukemia With t(9;11)(p22.3;q23.3); MLLT3-KMT2A; Acute Myeloid Leukemia With Variant MLL Translocations; Untreated Adult Acute Myeloid Leukemia

Encapsulation of Piper cabralanum (Piperaceae) nonpolar extract in poly(methyl methacrylate) by miniemulsion and evaluation of increase in the effectiveness of antileukemic activity in K562 cells.

PubMed

Mendes, Anderson Nogueira; Filgueiras, Lívia Alves; Siqueira, Monica Regina Pimentel; Barbosa, Gleyce Moreno; Holandino, Carla; de Lima Moreira, Davyson; Pinto, José Carlos; Nele, Marcio

2017-01-01

This study aimed to synthesize and characterize nanoparticles (NPs) of poly(methyl methacrylate) (PMMA) and evaluate their ability to incorporate plant extracts with antitumor activity and low dissolution in aqueous media. The extract used was n -hexane partition of the methanol extract of Piper cabralanum (PCA-HEX). PMMA NPs were obtained using the mini-emulsion method, which was able to encapsulate almost 100% of PCA-HEX. The synthesized polymeric particles presented with a size of 200 nm and a negative charge. Cytotoxicity tests by MTT and trypan blue assays showed that NPs without PCA-HEX did not kill leukemic cells (K562 cells). NPs containing PCA-HEX were able to enhance cell death when compared to pure extract. The results showed that PMMA NPs could be useful as a drug delivery system as they can enhance the antitumor activity of the PCA-HEX extract by more than 20-fold. PMMA NPs containing plant extracts with antitumor activities may be an alternative to control the evolution of diseases such as leukemia.

Encapsulation of Piper cabralanum (Piperaceae) nonpolar extract in poly(methyl methacrylate) by miniemulsion and evaluation of increase in the effectiveness of antileukemic activity in K562 cells

PubMed Central

Mendes, Anderson Nogueira; Filgueiras, Lívia Alves; Siqueira, Monica Regina Pimentel; Barbosa, Gleyce Moreno; Holandino, Carla; de Lima Moreira, Davyson; Pinto, José Carlos; Nele, Marcio

2017-01-01

This study aimed to synthesize and characterize nanoparticles (NPs) of poly(methyl methacrylate) (PMMA) and evaluate their ability to incorporate plant extracts with antitumor activity and low dissolution in aqueous media. The extract used was n-hexane partition of the methanol extract of Piper cabralanum (PCA-HEX). PMMA NPs were obtained using the mini-emulsion method, which was able to encapsulate almost 100% of PCA-HEX. The synthesized polymeric particles presented with a size of 200 nm and a negative charge. Cytotoxicity tests by MTT and trypan blue assays showed that NPs without PCA-HEX did not kill leukemic cells (K562 cells). NPs containing PCA-HEX were able to enhance cell death when compared to pure extract. The results showed that PMMA NPs could be useful as a drug delivery system as they can enhance the antitumor activity of the PCA-HEX extract by more than 20-fold. PMMA NPs containing plant extracts with antitumor activities may be an alternative to control the evolution of diseases such as leukemia. PMID:29200848

Epigenetic Regulation of Myeloid Cells

PubMed Central

IVASHKIV, LIONEL B.; PARK, SUNG HO

2017-01-01

Epigenetic regulation in myeloid cells is crucial for cell differentiation and activation in response to developmental and environmental cues. Epigenetic control involves posttranslational modification of DNA or chromatin, and is also coupled to upstream signaling pathways and transcription factors. In this review, we summarize key epigenetic events and how dynamics in the epigenetic landscape of myeloid cells shape the development, immune activation, and innate immune memory. PMID:27337441

General Information about Adult Acute Myeloid Leukemia

MedlinePlus

... Acute Myeloid Leukemia Treatment (PDQ®)–Patient Version General Information About Adult Acute Myeloid Leukemia Go to Health ... the PDQ Adult Treatment Editorial Board . Clinical Trial Information A clinical trial is a study to answer ...

Myeloid-derived suppressor cells can be efficiently generated from human hematopoietic progenitors and peripheral blood monocytes.

PubMed

Casacuberta-Serra, Sílvia; Parés, Marta; Golbano, Arantxa; Coves, Elisabet; Espejo, Carmen; Barquinero, Jordi

2017-07-01

Myeloid-derived suppressor cells (MDSCs) have an important role in controlling inflammation. As such, they are both a therapeutic target and, based on the administration of ex vivo-generated MDSCs, a therapeutic tool. However, there are relatively few reports describing methods to generate human MDSCs, and most of them rely on cells obtained from peripheral blood monocytes. We investigated alternative approaches to the generation of MDSCs from hematopoietic progenitors and monocytes. Purified CD34 + hematopoietic progenitors from apheresis products and CD14 + cells isolated from buffy coats were cultured in the presence of different combinations of cytokines. The resulting myeloid cell populations were then characterized phenotypically and functionally. Progenitor cells cultured in the presence of SCF+TPO+FLT3-L+GM-CSF+IL-6 gave rise to both monocytic (M)- and granulocytic (G)-MDSCs but production of the latter was partially inhibited by IL-3. M-MDSCs but not G-MDSCs were obtained by culturing peripheral blood monocytes with GM-CSF+IL-6 or GM-CSF+TGF-β1 for 6 days. CD14 expression was downregulated in the cultured cells. PD-L1 expression at baseline was lower in hematopoietic progenitor cell-derived than in monocyte-derived MDSCs, but was markedly increased in response to stimulation with LPS+IFN-γ. The functionality of the two MDSC subtypes was confirmed in studies of the suppression of allogeneic and mitogen-induced proliferation and by cytokine profiling. Here we describe both the culture conditions that allow the generation of MDSCs and the phenotypical and functional characterization of these cell populations.

Characterization of resistance to rhabdovirus and retrovirus infection in a human myeloid cell line.

PubMed

Boso, Guney; Somia, Nikunj V

2015-01-01

Viruses interact with various permissive and restrictive factors in host cells throughout their replication cycle. Cell lines that are non-permissive to viral infection have been particularly useful in discovering host cell proteins involved in viral life cycles. Here we describe the characterization of a human myeloid leukemia cell line, KG-1, that is resistant to infection by retroviruses and a Rhabdovirus. We show that KG-1 cells are resistant to infection by Vesicular Stomatits Virus as well as VSV Glycoprotein (VSVG) pseudotyped retroviruses due to a defect in binding. Moreover our results indicate that entry by xenotropic retroviral envelope glycoprotein RD114 is impaired in KG-1 cells. Finally we characterize a post- entry block in the early phase of the retroviral life cycle in KG-1 cells that renders the cell line refractory to infection. This cell line will have utility in discovering proteins involved in infection by VSV and HIV-1.

Antileukemic Potential of Momordica charantia Seed Extracts on Human Myeloid Leukemic HL60 Cells

PubMed Central

Soundararajan, Ramani; Prabha, Punit; Rai, Umesh; Dixit, Aparna

2012-01-01

Momordica charantia (bitter gourd) has been used in the traditional system of medicine for the treatment of various diseases. Anticancer activity of M. charantia extracts has been demonstrated by numerous in vitro and in vivo studies. In the present study, we investigated the differentiation inducing potential of fractionated M. charantia seed extracts in human myeloid HL60 cells. We found that the HL60 cells treated with the fractionated seed extracts differentiated into granulocytic lineage as characterized by NBT staining, CD11b expression, and specific esterase activity. The differentiation inducing principle was found to be heat-stable, and organic in nature. The differentiation was accompanied by a downregulation of c-myc transcript, indicating the involvement of c-myc pathway, at least in part, in differentiation. Taken together these results indicate that fractionated extracts of M. charantia seeds possess differentiation inducing activity and therefore can be evaluated for their potential use in differentiation therapy for leukemia in combination with other inducers of differentiation. PMID:22654956

Selinexor and Chemotherapy in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

ClinicalTrials.gov

2018-04-02

Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia

Ki-67 Expression in Human Tumors Measured by Flow Cytometry

DTIC Science & Technology

1990-01-01

Analyzed Fresh tissues obtained from the lymph node biopsies of 30 patients diagnosed as having non-Hodgkin’s lymphoma, nine biopsies identified as...breast tumors, and eight biopsies identified as colon tumors were included in this study. Cell Lines K562 Cell Line The human ervthroleukemia cell line...petri dish. While holding the tissue with toothed forceps , it wa,-is minced with scissors. Ujsing at transfer pip:., tissue fragments we re aspirated

Resveratrol Downregulates Interleukin-6-Stimulated Sonic Hedgehog Signaling in Human Acute Myeloid Leukemia

PubMed Central

Su, Yu-Chieh; Li, Szu-Chin; Wu, Yin-Chi; Wang, Li-Min; Chao, K. S. Clifford; Liao, Hui-Fen

2013-01-01

IL-6 and sonic hedgehog (Shh) signaling molecules are considered to maintain the growth of cancer stem cells (CSCs). Resveratrol, an important integrant in traditional Chinese medicine, possesses certain antitumor effects. However, the mechanisms on regulating acute myeloid leukemia (AML) are unclear. This study first used human subjects to demonstrate that the plasma levels of IL-6 and IL-1β in AML patients were higher and lower, respectively, than healthy donors. The expression of Shh preproproteins, and C- and N-terminal Shh peptides increased in bone marrow and peripheral blood mononuclear cells isolated from AML patients, and the plasma N-Shh secretion was greater. To further clarify the effect of IL-6 and resveratrol in Shh signaling, human AML HL-60 cells were tested. IL-6 upregulated Shh and Gli-1 expression and was accompanied by an increase of cell viability. Resveratrol significantly decreased CSC-related Shh expression, Gli-1 nuclear translocation, and cell viability in IL-6-treated HL-60 cells and had synergistic effect with Shh inhibitor cyclopamine on inhibiting cell growth. Conclusions. IL-6 stimulated the growth of AML cells through Shh signaling, and this effect might be blocked by resveratrol. Further investigations of Shh as a prognostic marker and resveratrol as a therapeutic drug target to CSCs in AML are surely warranted. PMID:23533494

Eos Negatively Regulates Human γ-globin Gene Transcription during Erythroid Differentiation

PubMed Central

Yu, Hai-Chuan; Zhao, Hua-Lu; Wu, Zhi-Kui; Zhang, Jun-Wu

2011-01-01

Background Human globin gene expression is precisely regulated by a complicated network of transcription factors and chromatin modifying activities during development and erythropoiesis. Eos (Ikaros family zinc finger 4, IKZF4), a member of the zinc finger transcription factor Ikaros family, plays a pivotal role as a repressor of gene expression. The aim of this study was to examine the role of Eos in globin gene regulation. Methodology/Principal Findings Western blot and quantitative real-time PCR detected a gradual decrease in Eos expression during erythroid differentiation of hemin-induced K562 cells and Epo-induced CD34+ hematopoietic stem/progenitor cells (HPCs). DNA transfection and lentivirus-mediated gene transfer demonstrated that the enforced expression of Eos significantly represses the expression of γ-globin, but not other globin genes, in K562 cells and CD34+ HPCs. Consistent with a direct role of Eos in globin gene regulation, chromatin immunoprecipitaion and dual-luciferase reporter assays identified three discrete sites located in the DNase I hypersensitivity site 3 (HS3) of the β-globin locus control region (LCR), the promoter regions of the Gγ- and Aγ- globin genes, as functional binding sites of Eos protein. A chromosome conformation capture (3C) assay indicated that Eos may repress the interaction between the LCR and the γ-globin gene promoter. In addition, erythroid differentiation was inhibited by enforced expression of Eos in K562 cells and CD34+ HPCs. Conclusions/Significance Our results demonstrate that Eos plays an important role in the transcriptional regulation of the γ-globin gene during erythroid differentiation. PMID:21829552

Childhood Acute Myeloid Leukemia Treatment (PDQ®)—Health Professional Version

Cancer.gov

Acute myeloid leukemia (AML), juvenile myelomonocytic leukemia (JMML), acute promyelocytic leukemia (APL) and chronic myeloid leukemia (CML) account for about 20% of childhood myeloid leukemias. Other myeloid malignancies include transient abnormal myelopoiesis and myelodysplastic syndrome. Get detailed information about the classification, clinical presentation, diagnostic and molecular evaluation, prognosis, and treatment of newly diagnosed and recurrent disease in this summary for clinicians.

Risk of myeloid neoplasms after solid organ transplantation

PubMed Central

Morton, Lindsay M.; Gibson, Todd M.; Clarke, Christina A.; Lynch, Charles F.; Anderson, Lesley A.; Pfeiffer, Ruth; Landgren, Ola; Weisenburger, Dennis D.; Engels, Eric A.

2014-01-01

Solid organ transplant recipients have elevated cancer risks, due in part to pharmacologic immunosuppression. However, little is known about risks for hematologic malignancies of myeloid origin. We linked the US Scientific Registry of Transplant Recipients with 15 population-based cancer registries to ascertain cancer occurrence among 207,859 solid organ transplants (1987–2009). Solid organ transplant recipients had significantly elevated risk for myeloid neoplasms, with standardized incidence ratios (SIRs) of 4.6 (95% confidence interval 3.8–5.6; N=101) for myelodysplastic syndromes (MDS), 2.7 (2.2–3.2; N=125) for acute myeloid leukemia (AML), 2.3 (1.6–3.2; N=36) for chronic myeloid leukemia, and 7.2 (5.4–9.3; N=57) for polycythemia vera. SIRs were highest among younger individuals and varied by time since transplantation and organ type (Poisson regression P<0.05 for all comparisons). Azathioprine for initial maintenance immunosuppression increased risk for MDS (P=0.0002) and AML (2–5 years after transplantation, P=0.0163). Overall survival following AML/MDS among transplant recipients was inferior to that of similar patients reported to US cancer registries (log-rank P<0.0001). Our novel finding of increased risks for specific myeloid neoplasms after solid organ transplantation supports a role for immune dysfunction in myeloid neoplasm etiology. The increased risks and inferior survival should heighten clinician awareness of myeloid neoplasms during follow-up of transplant recipients. PMID:24727673

MTHFR gene polymorphism and risk of myeloid leukemia: a meta-analysis.

PubMed

Dong, Song; Liu, Yueling; Chen, Jieping

2014-09-01

An increasing body of evidence has shown that the amino acid changes at position 1298 might eliminate methylenetetrahydrofolate reductase (MTHFR) enzyme activity, leading to insufficient folic acid and subsequent human chromosome breakage. Epidemiological studies have linked MTHFR single-nucleotide polymorphism (SNP) rs1801131 to myeloid leukemia risk, with considerable discrepancy in their results. We therefore were prompted to clarify this issue by use of a meta-analysis. The search terms were used to cover the possible reports in the MEDLINE, Web of Knowledge, and China National Knowledge Infrastructure (CNKI) databases. Odds ratios were estimated to assess the association of SNP rs1801131 with myeloid leukemia risk. Statistical heterogeneity was detected using the Q-statistic and I (2) metric. Subgroup analysis was performed by ethnicity, histological subtype, and Hardy-Weinberg equilibrium (HWE). This meta-analysis of eight publications with a total of 1,114 cases and 3,227 controls revealed no global association. Nor did the subgroup analysis according to histological subtype and HWE show any significant associations. However, Asian individuals who harbored the CC genotype were found to have 1.66-fold higher risk of myeloid leukemia (odds ratio, 1.66; 95 % confidence interval, 1.10 to 2.49; P h = 0.342; I (2) = 0.114). Our meta-analysis has presented evidence supporting a possible association between the CC genotype of MTHFR SNP rs1801131 and myeloid leukemia in Asian populations.

Mangiferin activates Nrf2-antioxidant response element signaling without reducing the sensitivity to etoposide of human myeloid leukemia cells in vitro

PubMed Central

Zhang, Ben-ping; Zhao, Jie; Li, Shan-shan; Yang, Li-jing; Zeng, Ling-lan; Chen, Yan; Fang, Jun

2014-01-01

Aim: Mangiferin is glucosylxanthone extracted from plants of the Anacardiaceae and Gentianaceae families. The aim of this study was to investigate the effects of mangiferin on Nrf2-antioxidant response element (ARE) signaling and the sensitivity to etoposide of human myeloid leukemia cells in vitro. Methods: Human HL-60 myeloid leukemia cells and mononuclear human umbilical cord blood cells (MNCs) were examined. Nrf2 protein was detected using immunofluorescence staining and Western blotting. Binding of Nrf2 to ARE was examined with electrophoretic mobility shift assay. The level of NQO1 was assessed with real-time RT-PCR and Western blotting. DCFH-DA was used to evaluate intracellular ROS level. Cell proliferation and apoptosis were analyzed using MTT and flow cytometry, respectively. Results: Mangiferin (50 μmol/L) significantly increased Nrf2 protein accumulation in HL-60 cells, particularly in the nucleus. Mangiferin also enhanced the binding of Nrf2 to an ARE, significantly up-regulated NQO1 expression and reduced intracellular ROS in HL60 cells. Mangiferin alone dose-dependently inhibited the proliferation of HL-60 cells. Mangiferin (50 mol/L) did not attenuate etoposide-induced cytotoxicity in HL-60 cells, and combined treatment of mangiferin with low concentration of etoposide (0.8 μg/mL) even increased the cell inhibition rate. Nor did mangiferin change the rate of etoposide-induced apoptosis in HL-60 cells. In MNCs, mangiferin significantly relieved oxidative stress, but attenuated etoposide-induced cytotoxicity. Conclusion: Mangiferin is a novel Nrf2 activator that reduces oxidative stress and protects normal cells without reducing the sensitivity to etoposide of HL-60 leukemia cells in vitro. Mangiferin may be a potential chemotherapy adjuvant. PMID:24374812

Mangiferin activates Nrf2-antioxidant response element signaling without reducing the sensitivity to etoposide of human myeloid leukemia cells in vitro.

PubMed

Zhang, Ben-ping; Zhao, Jie; Li, Shan-shan; Yang, Li-jing; Zeng, Ling-lan; Chen, Yan; Fang, Jun

2014-02-01

Mangiferin is glucosylxanthone extracted from plants of the Anacardiaceae and Gentianaceae families. The aim of this study was to investigate the effects of mangiferin on Nrf2-antioxidant response element (ARE) signaling and the sensitivity to etoposide of human myeloid leukemia cells in vitro. Human HL-60 myeloid leukemia cells and mononuclear human umbilical cord blood cells (MNCs) were examined. Nrf2 protein was detected using immunofluorescence staining and Western blotting. Binding of Nrf2 to ARE was examined with electrophoretic mobility shift assay. The level of NQO1 was assessed with real-time RT-PCR and Western blotting. DCFH-DA was used to evaluate intracellular ROS level. Cell proliferation and apoptosis were analyzed using MTT and flow cytometry, respectively. Mangiferin (50 μmol/L) significantly increased Nrf2 protein accumulation in HL-60 cells, particularly in the nucleus. Mangiferin also enhanced the binding of Nrf2 to an ARE, significantly up-regulated NQO1 expression and reduced intracellular ROS in HL60 cells. Mangiferin alone dose-dependently inhibited the proliferation of HL-60 cells. Mangiferin (50 mol/L) did not attenuate etoposide-induced cytotoxicity in HL-60 cells, and combined treatment of mangiferin with low concentration of etoposide (0.8 μg/mL) even increased the cell inhibition rate. Nor did mangiferin change the rate of etoposide-induced apoptosis in HL-60 cells. In MNCs, mangiferin significantly relieved oxidative stress, but attenuated etoposide-induced cytotoxicity. Mangiferin is a novel Nrf2 activator that reduces oxidative stress and protects normal cells without reducing the sensitivity to etoposide of HL-60 leukemia cells in vitro. Mangiferin may be a potential chemotherapy adjuvant.

Hematopoietic colony formation from human growth factor-dependent TF1 cells and human cord blood myeloid progenitor cells depends on SHP2 phosphatase function.

PubMed

Broxmeyer, Hal E; Etienne-Julan, Maryse; Gotoh, Akihiko; Braun, Stephen E; Lu, Li; Cooper, Scott; Feng, Gen-Sheng; Li, Xing Jun; Chan, Rebecca J

2013-03-15

The protein tyrosine phosphatase, SHP2, is widely expressed; however, previous studies demonstrated that hematopoietic cell development more stringently requires Shp2 expression compared to other tissues. Furthermore, somatic gain-of-function SHP2 mutants are commonly found in human myeloid leukemias. Given that pharmacologic inhibitors to SHP2 phosphatase activity are currently in development as putative antileukemic agents, we conducted a series of experiments examining the necessity of SHP2 phosphatase activity for human hematopoiesis. Anti-sense oligonucleotides to human SHP2 coding sequences reduced human cord blood- and human cell line, TF1-derived colony formation. Expression of truncated SHP2 bearing its Src homology 2 (SH2) domains, but lacking the phosphatase domain similarly reduced human cord blood- and TF1-derived colony formation. Mechanistically, expression of truncated SHP2 reduced the interaction between endogenous, full-length SHP2 with the adapter protein, Grb2. To verify the role of SHP2 phosphatase function in human hematopoietic cell development, human cord blood CD34+ cells were transduced with a leukemia-associated phosphatase gain-of-function SHP2 mutant or with a phosphatase dead SHP2 mutant, which indicated that increased phosphatase function enhanced, while decreased SHP2 phosphatase function reduced, human cord blood-derived colonies. Collectively, these findings indicate that SHP2 phosphatase function regulates human hematopoietic cell development and imply that the phosphatase component of SHP2 may serve as a pharmacologic target in human leukemias bearing increased SHP2 phosphatase activity.

Expression of c-Fes protein isoforms correlates with differentiation in myeloid leukemias.

PubMed

Carlson, Anne; Berkowitz, Jeanne McAdara; Browning, Damaris; Slamon, Dennis J; Gasson, Judith C; Yates, Karen E

2005-05-01

The cellular fes gene encodes a 93-kilodalton protein-tyrosine kinase (p93) that is expressed in both normal and neoplastic myeloid cells. Increased c-Fes expression is associated with differentiation in normal myeloid cells and cell lines. Our hypothesis was that primary leukemia cells would show a similar pattern of increased expression in more differentiated cells. Therefore, we compared c-Fes expression in cells with an undifferentiated, blast phenotype (acute myelogenous leukemia--AML) to cells with a differentiated phenotype (chronic myelogenous leukemia--CML). Instead of differences in p93 expression levels, we found complex patterns of c-Fes immunoreactive proteins that corresponded with differentiation in normal and leukemic myeloid cells. The "blast" pattern consisted of c-Fes immunoreactive proteins p93, p74, and p70; the "differentiated" pattern showed two additional c-Fes immunoreactive proteins, p67 and p62. Using mRNA from mouse and human cell lines, we found deletion of one or more exons in the c-fes mRNA. Those deletions predicted truncation of conserved domains (CDC15/FCH and SH2) involved in protein-protein interactions. No deletions were found, however, within the kinase domain. We infer that alternative splicing generates a family of c-Fes proteins. This may be a mechanism to direct the c-Fes kinase domain to different subcellular locations and/or substrates at specific stages of myeloid cell differentiation.

Myeloid malignancies: mutations, models and management

PubMed Central

2012-01-01

Myeloid malignant diseases comprise chronic (including myelodysplastic syndromes, myeloproliferative neoplasms and chronic myelomonocytic leukemia) and acute (acute myeloid leukemia) stages. They are clonal diseases arising in hematopoietic stem or progenitor cells. Mutations responsible for these diseases occur in several genes whose encoded proteins belong principally to five classes: signaling pathways proteins (e.g. CBL, FLT3, JAK2, RAS), transcription factors (e.g. CEBPA, ETV6, RUNX1), epigenetic regulators (e.g. ASXL1, DNMT3A, EZH2, IDH1, IDH2, SUZ12, TET2, UTX), tumor suppressors (e.g. TP53), and components of the spliceosome (e.g. SF3B1, SRSF2). Large-scale sequencing efforts will soon lead to the establishment of a comprehensive repertoire of these mutations, allowing for a better definition and classification of myeloid malignancies, the identification of new prognostic markers and therapeutic targets, and the development of novel therapies. Given the importance of epigenetic deregulation in myeloid diseases, the use of drugs targeting epigenetic regulators appears as a most promising therapeutic approach. PMID:22823977

Calcineurin/NFAT signalling inhibits myeloid haematopoiesis.

PubMed

Fric, Jan; Lim, Clarice X F; Koh, Esther G L; Hofmann, Benjamin; Chen, Jinmiao; Tay, Hock Soon; Mohammad Isa, Siti Aminah Bte; Mortellaro, Alessandra; Ruedl, Christiane; Ricciardi-Castagnoli, Paola

2012-04-01

Nuclear factor of activated T cells (NFAT) comprises a family of transcription factors that regulate T cell development, activation and differentiation. NFAT signalling can also mediate granulocyte and dendritic cell (DC) activation, but it is unknown whether NFAT influences their development from progenitors. Here, we report a novel role for calcineurin/NFAT signalling as a negative regulator of myeloid haematopoiesis. Reconstituting lethally irradiated mice with haematopoietic stem cells expressing an NFAT-inhibitory peptide resulted in enhanced development of the myeloid compartment. Culturing bone marrow cells in media supplemented with Flt3-L in the presence of the calcineurin/NFAT inhibitor Cyclosporin A increased numbers of differentiated DC. Global gene expression analysis of untreated DC and NFAT-inhibited DC revealed differential expression of transcripts that regulate cell cycle and apoptosis. In conclusion, these results provide evidence that calcineurin/NFAT signalling negatively regulates myeloid lineage development. The finding that inhibition of NFAT enhances myeloid development provides a novel insight into understanding how the treatment with drugs targeting calcineurin/NFAT signalling influence the homeostasis of the innate immune system. Copyright © 2012 EMBO Molecular Medicine.

Phase I Combination of Midostaurin, Bortezomib, and Chemo in Relapsed/Refractory Acute Myeloid Leukemia

ClinicalTrials.gov

2016-07-04

Acute Myeloid Leukemia; Acute Myeloid Leukemia With Multilineage Dysplasia Following; Myelodysplastic Syndrome; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia

40 CFR 60.562-2 - Standards: Equipment leaks of VOC.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Volatile Organic Compound (VOC) Emissions from the Polymer Manufacturing Industry § 60.562-2 Standards... feature of the pump whereby polymer fluid used to provide lubrication and/or cooling of the pump shaft...

Lenalidomide and Cytarabine in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

ClinicalTrials.gov

2018-06-18

Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Recurrent Adult Acute Myeloid Leukemia

Regression Analysis of Combined Gene Expression Regulation in Acute Myeloid Leukemia

PubMed Central

Li, Yue; Liang, Minggao; Zhang, Zhaolei

2014-01-01

Gene expression is a combinatorial function of genetic/epigenetic factors such as copy number variation (CNV), DNA methylation (DM), transcription factors (TF) occupancy, and microRNA (miRNA) post-transcriptional regulation. At the maturity of microarray/sequencing technologies, large amounts of data measuring the genome-wide signals of those factors became available from Encyclopedia of DNA Elements (ENCODE) and The Cancer Genome Atlas (TCGA). However, there is a lack of an integrative model to take full advantage of these rich yet heterogeneous data. To this end, we developed RACER (Regression Analysis of Combined Expression Regulation), which fits the mRNA expression as response using as explanatory variables, the TF data from ENCODE, and CNV, DM, miRNA expression signals from TCGA. Briefly, RACER first infers the sample-specific regulatory activities by TFs and miRNAs, which are then used as inputs to infer specific TF/miRNA-gene interactions. Such a two-stage regression framework circumvents a common difficulty in integrating ENCODE data measured in generic cell-line with the sample-specific TCGA measurements. As a case study, we integrated Acute Myeloid Leukemia (AML) data from TCGA and the related TF binding data measured in K562 from ENCODE. As a proof-of-concept, we first verified our model formalism by 10-fold cross-validation on predicting gene expression. We next evaluated RACER on recovering known regulatory interactions, and demonstrated its superior statistical power over existing methods in detecting known miRNA/TF targets. Additionally, we developed a feature selection procedure, which identified 18 regulators, whose activities clustered consistently with cytogenetic risk groups. One of the selected regulators is miR-548p, whose inferred targets were significantly enriched for leukemia-related pathway, implicating its novel role in AML pathogenesis. Moreover, survival analysis using the inferred activities identified C-Fos as a potential AML

Eltrombopag Olamine in Treating Patients With Relapsed/Refractory Acute Myeloid Leukemia

ClinicalTrials.gov

2016-04-04

Adult Acute Basophilic Leukemia; Adult Acute Eosinophilic Leukemia; Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Recurrent Adult Acute Myeloid Leukemia

cDNA cloning, tissue distribution, and chromosomal localization of myelodysplasia/Myeloid Leukemia Factor 2 (MLF2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuefer, M.U.; Valentine, V.; Behm, F.G.

A fusion gene between nucleophosmin (NPM) and myelodysplasia/myeloid leukemia factor 1 (MLF1) and myelodysplasia/myeloid leukemia factor 1 (MLF1) is formed by a recurrent t(3;5)(q25.1;q34) in myelodysplastic syndrome and acute myeloid leukemia. Here we report the identification of a novel gene, MLF2, which contains an open reading frame of 744 bp encoding a 248-amino-acid protein highly related to the previously identified MLF1 protein (63% similarity, 40% identity). In contrast to the tissue-restricted expression pattern of MLF1, and MLF2 messenger RNA is expressed ubiquitously. The MLF2 gene locus was mapped by fluorescence in situ hybridization to human chromosome 12p13, a chromosomal regionmore » frequently involved in translocations and deletions in acute leukemias of lymphoid or myeloid lineage. In a physical map of chromosome 12, MLF2 was found to reside on the yeast artificial chromosome clone 765b9. Southern blotting analysis of malignant cell DNAs prepared from a series of acute lymphoblastic leukemia cases with translocations involving chromosome arm 12p, as well as a group of acute myeloid leukemias with various cytogenetic abnormalities, failed to reveal MLF2 gene rearrangements. 19 refs., 2 figs.« less

Individual and combined tumoricidal effects of dexamethasone and interferons on human leukocyte cell lines.

PubMed

Pan, L Y; Guyre, P M

1988-02-01

We investigated the influence of glucocorticoids on two effects of interferons (IFNs) which are thought to relate to their antitumor actions: cytotoxic activity and induction of HLA antigen expression. We treated human myeloid cell lines (U-937, HL-60, THP-1, K-562, and KG-1a), and T-(MOLT-4) and B- (Daudi) lymphoblastic cell lines with concentrations of IFN-alpha, IFN-gamma, and dexamethasone (Dex) which are commonly achieved in the circulation following therapeutic administration. The results show that for every cell line except Daudi, the greatest inhibition of cell growth occurred when IFN-gamma and Dex treatments were combined. The advantage of combined IFN-gamma and Dex treatment over treatment with either agent alone was most dramatic for the three cell lines (U-937, HL-60, and THP-1) which have monocytoid characteristics. There was also more growth inhibition by the combination of IFN-alpha and Dex than by either agent alone for all seven cell lines tested. The induction of HLA antigen expression by IFN-alpha and IFN-gamma, an effect which could increase recognition of the tumor cells by the immune system, was as great or greater in the presence of Dex as in its absence. These results demonstrate that glucocorticoids do not inhibit, and in some cases enhance, two effects of IFNs that appear to be related to their antitumor actions: inhibition of tumor cell proliferation and enhancement of HLA antigen expression.

[Preliminary establishment of transplanted human chronic myeloid leukemia model in nude mice].

PubMed

Li, Xian-Min; Ding, Xin; Zhang, Long-Zhen; Cen, Jian-Nong; Chen, Zi-Xing

2011-12-01

Chronic myeloid leukemia (CML) is a malignant clonal disease derived from hematopoietic stem cells. CML stem cells were thought to be the root which could lead disease development and ultimately rapid change. However, a stable animal model for studying the characteristics of CML stem cells is currently lacking. This study was aimed to establish a transplanted human CML nude-mice model to further explore the biological behavior of CML stem cells in vivo, and to enrich CML stem cells in nude mice by series transplantation. The 4 - 6 weeks old BALB/c nude mice pretreated by splenectomy (S), cytoxan intraperitoneal injection (C) and sublethal irradiation (I) were transplanted intravenously with (5 - 7) × 10(7) of bone marrow mononuclear cells from CML patients in chronic phase. Alternatively, 4 - 6 weeks old BALB/c nude mice pretreated by lethal irradiation were transplanted intravenously with 5 × 10(6) homologous bone marrow cells of BALB/c nude mice together with (5 - 7) × 10(7) of bone marrow mononuclear cells from CML patients in chronic phase simultaneously. The leukemic cells engrafted and infiltrated in organs and bone marrow of the mice were tracked by reverse transcription-polymerase chain reaction (RT-PCR), plastic-embedded biopsy and flow cytometry. The results of these two methods were compared. The results showed that human CML cells engrafted and infiltrating into the bone marrow of two nude mice pretreated with SCI could be detected. In spite of the low successful rate, results suggested the feasibility of this method by using BALB/c nude mice as a human CML animal model. In contrast, in nude mice pretreated by the lethal dose irradiation, CML cells in the bone marrow could not be found. It is concluded that human bone marrow CML cells can results in leukemia in nude mice pretreated by SCI. Thus this study provides a new strategy for establishment of CML animal models which deserves further elaboration.

Activation of triggering receptor expressed on myeloid cells-1 on human neutrophils by marburg and ebola viruses.

PubMed

Mohamadzadeh, Mansour; Coberley, Sadie S; Olinger, Gene G; Kalina, Warren V; Ruthel, Gordon; Fuller, Claudette L; Swenson, Dana L; Pratt, William D; Kuhns, Douglas B; Schmaljohn, Alan L

2006-07-01

Marburg virus (MARV) and Ebola virus (EBOV), members of the viral family Filoviridae, cause fatal hemorrhagic fevers in humans and nonhuman primates. High viral burden is coincident with inadequate adaptive immune responses and robust inflammatory responses, and virus-mediated dysregulation of early host defenses has been proposed. Recently, a novel class of innate receptors called the triggering receptors expressed in myeloid cells (TREM) has been discovered and shown to play an important role in innate inflammatory responses and sepsis. Here, we report that MARV and EBOV activate TREM-1 on human neutrophils, resulting in DAP12 phosphorylation, TREM-1 shedding, mobilization of intracellular calcium, secretion of proinflammatory cytokines, and phenotypic changes. A peptide specific to TREM-1 diminished the release of tumor necrosis factor alpha by filovirus-activated human neutrophils in vitro, and a soluble recombinant TREM-1 competitively inhibited the loss of cell surface TREM-1 that otherwise occurred on neutrophils exposed to filoviruses. These data imply direct activation of TREM-1 by filoviruses and also indicate that neutrophils may play a prominent role in the immune and inflammatory responses to filovirus infections.

Small Molecule Inhibition of cAMP Response Element Binding Protein in Human Acute Myeloid Leukemia Cells

PubMed Central

Mitton, Bryan; Chae, Hee-Don; Hsu, Katie; Dutta, Ritika; Aldana-Masangkay, Grace; Ferrari, Roberto; Davis, Kara; Tiu, Bruce C.; Kaul, Arya; Lacayo, Norman; Dahl, Gary; Xie, Fuchun; Li, Bingbing X.; Breese, Marcus R.; Landaw, Elliot M.; Nolan, Garry; Pellegrini, Matteo; Romanov, Sergei; Xiao, Xiangshu; Sakamoto, Kathleen M.

2016-01-01

The transcription factor CREB (cAMP Response Element Binding Protein) is overexpressed in the majority of acute myeloid leukemia (AML) patients, and this is associated with a worse prognosis. Previous work revealed that CREB overexpression augmented AML cell growth, while CREB knockdown disrupted key AML cell functions in vitro. In contrast, CREB knockdown had no effect on long-term hematopoietic stem cell activity in mouse transduction/transplantation assays. Together, these studies position CREB as a promising drug target for AML. To test this concept, a small molecule inhibitor of CREB, XX-650-23, was developed. This molecule blocks a critical interaction between CREB and its required co-activator CBP (CREB Binding Protein), leading to disruption of CREB-driven gene expression. Inhibition of CBP-CREB interaction induced apoptosis and cell cycle arrest in AML cells, and prolonged survival in vivo in mice injected with human AML cells. XX-650-23 had little toxicity on normal human hematopoietic cells and tissues in mice. To understand the mechanism of XX-650-23, we performed RNA-seq, ChIP-seq and Cytometry Time of Flight with human AML cells. Our results demonstrate that small molecule inhibition of CBP-CREB interaction mostly affects apoptotic, cell cycle, and survival pathways, which may represent a novel approach for AML therapy. PMID:27211267

Regulatory Myeloid Cells in Transplantation

PubMed Central

Rosborough, Brian R.; Raïch-Regué, Dàlia; Turnquist, Heth R.; Thomson, Angus W.

2013-01-01

Regulatory myeloid cells (RMC) are emerging as novel targets for immunosuppressive (IS) agents and hold considerable promise as cellular therapeutic agents. Herein, we discuss the ability of regulatory macrophages (Mreg), regulatory dendritic cells (DCreg) and myeloid-derived suppressor cells (MDSC) to regulate alloimmunity, their potential as cellular therapeutic agents and the IS agents that target their function. We consider protocols for the generation of RMC and the selection of donor- or recipient-derived cells for adoptive cell therapy. Additionally, the issues of cell trafficking and antigen (Ag) specificity following RMC transfer are discussed. Improved understanding of the immunobiology of these cells has increased the possibility of moving RMC into the clinic to reduce the burden of current IS agents and promote Ag-specific tolerance. In the second half of this review, we discuss the influence of established and experimental IS agents on myeloid cell populations. IS agents believed historically to act primarily on T cell activation and proliferation are emerging as important regulators of RMC function. Better insights into the influence of IS agents on RMC will enhance our ability to develop cell therapy protocols to promote the function of these cells. Moreover, novel IS agents may be designed to target RMC in situ to promote Ag-specific immune regulation in transplantation and usher in a new era of immune modulation exploiting cells of myeloid origin. PMID:24092382

Do We Know What Causes Chronic Myeloid Leukemia?

MedlinePlus

... Be Prevented? More In Chronic Myeloid Leukemia About Chronic Myeloid Leukemia Causes, Risk Factors, and Prevention Early Detection, Diagnosis, and Staging Treatment After Treatment Back To Top Imagine a world ...

Reengineering cyt b562 for hydrogen production: A facile route to artificial hydrogenases.

PubMed

Sommer, Dayn Joseph; Vaughn, Michael David; Clark, Brett Colby; Tomlin, John; Roy, Anindya; Ghirlanda, Giovanna

2016-05-01

Bioinspired, protein-based molecular catalysts utilizing base metals at the active are emerging as a promising avenue to sustainable hydrogen production. The protein matrix modulates the intrinsic reactivity of organometallic active sites by tuning second-sphere and long-range interactions. Here, we show that swapping Co-Protoporphyrin IX for Fe-Protoporphyrin IX in cytochrome b562 results in an efficient catalyst for photoinduced proton reduction to molecular hydrogen. Further, the activity of wild type Co-cyt b562 can be modulated by a factor of 2.5 by exchanging the coordinating methionine with alanine or aspartic acid. The observed turnover numbers (TON) range between 125 and 305, and correlate well with the redox potential of the Co-cyt b562 mutants. The photosensitized system catalyzes proton reduction with high efficiency even under an aerobic atmosphere, implicating its use for biotechnological applications. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson. Copyright © 2015 Elsevier B.V. All rights reserved.

Dido gene expression alterations are implicated in the induction of hematological myeloid neoplasms

PubMed Central

Fütterer, Agnes; Campanero, Miguel R.; Leonardo, Esther; Criado, Luis M.; Flores, Juana M.; Hernández, Jesús M.; San Miguel, Jesús F.; Martínez-A, Carlos

2005-01-01

The myelodysplastic/myeloproliferative diseases (MDS/MPDs) are a heterogeneous group of myeloid neoplasms that share characteristics with chronic myeloproliferative diseases and myelodysplastic syndromes. The broad spectrum of clinical manifestations makes MDS/MPDs extremely difficult to diagnose and treat, with a median survival time of 1–5 years. No single gene defect has been firmly associated with MDS/MPDs, and no animal models have been developed for these diseases. The association of deletions on chromosome 20q with myeloid malignancies suggests the presence of unidentified tumor suppressor genes in this region. Here we show that the recently identified death inducer–obliterator (Dido) gene gives rise to at least 3 polypeptides (Dido1, Dido2, and Dido3) through alternative splicing, and we map the human gene to the long arm of chromosome 20. We found that targeting of murine Dido caused a transplantable disease whose symptoms and signs suggested MDS/MPDs. Furthermore, 100% of human MDS/MPD patients analyzed showed Dido expression abnormalities, which we also found in other myeloid but not lymphoid neoplasms or in healthy donors. Our findings suggest that Dido might be one of the tumor suppressor genes at chromosome 20q and that the Dido-targeted mouse may be a suitable model for studying MDS/MPD diseases and testing new approaches to their diagnosis and treatment. PMID:16127461

Mpl traffics to the cell surface through conventional and unconventional routes.

PubMed

Cleyrat, Cédric; Darehshouri, Anza; Steinkamp, Mara P; Vilaine, Mathias; Boassa, Daniela; Ellisman, Mark H; Hermouet, Sylvie; Wilson, Bridget S

2014-09-01

Myeloproliferative neoplasms (MPNs) are often characterized by JAK2 or calreticulin (CALR) mutations, indicating aberrant trafficking in pathogenesis. This study focuses on Mpl trafficking and Jak2 association using two model systems: human erythroleukemia cells (HEL; JAK2V617F) and K562 myeloid leukemia cells (JAK2WT). Consistent with a putative chaperone role for Jak2, Mpl and Jak2 associate on both intracellular and plasma membranes (shown by proximity ligation assay) and siRNA-mediated knockdown of Jak2 led to Mpl trapping in the endoplasmic reticulum (ER). Even in Jak2 sufficient cells, Mpl accumulates in punctate structures that partially colocalize with ER-tracker, the ER exit site marker (ERES) Sec31a, the autophagy marker LC3 and LAMP1. Mpl was fused to miniSOG, a genetically encoded tag for correlated light and electron microscopy. Results suggest that a fraction of Mpl is taken up into autophagic structures from the ER and routed to autolyososomes. Surface biotinylation shows that both immature and mature Mpl reach the cell surface; in K562 cells Mpl is also released in exosomes. Both forms rapidly internalize upon ligand addition, while recovery is primarily attributed to immature Mpl. Mpl appears to reach the plasma membrane via both conventional ER-Golgi and autolysosome secretory pathways, as well as recycling. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Acute myeloid leukemia with leukemic pleural effusion.

PubMed

Chang, Hung

2013-10-01

Acute myeloid leukemia (AML) may be associated with extramedullary tumor growth, which is commonly known as myeloid sarcoma. Although AML with leukemic pleural effusion is considered rare, the true incidence is not clear. We report three cases of AML involving pleural effusion in this study. The cases were encountered in a single institute within two years, suggesting that leukemic effusion is more common than previously reported. Leukemic cells showed evidence of monocytic differentiation in all cases. Two patients presented with advanced AML. Both had concurrent myeloid sarcoma. Both were ineligible for intensive treatment and died soon after diagnosis of myeloid sarcoma. The third patient had pleural effusion upon diagnosis of AML. Remission was achieved and the effusion disappeared after treatment. We conclude leukemic effusion may become more common in an era of improved care and prolonged survival for AML patients. The prognostic impact is unclear and patients should be given standard AML treatment whenever possible. Copyright © 2012 Wiley Periodicals, Inc., a Wiley company.

Concurrent targeting Akt and sphingosine kinase 1 by A-674563 in acute myeloid leukemia cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Lin; Shaoyang Central Hospital, Hunan Province; Zhang, Yanan

Akt signaling plays a pivotal role in acute myeloid leukemia (AML) development and progression. In the present study, we evaluated the potential anti-AML activity by a novel Akt kinase inhibitor A-674563. Our results showed that A-674563 dose-dependently inhibited survival and proliferation of U937 AML cells and six lines of human AML progenitor cells, yet sparing human peripheral blood mononuclear leukocytes (PBMCs). A-674563 activated caspase-3/9 and apoptosis in the AML cells. Reversely, the pan-caspase inhibitor z-VAD-CHO dramatically alleviated A-674563-induced AML cell apoptosis and cytotoxicity. For the molecular study, we showed that A-674563 blocked Akt activation in U937 cells and human AMLmore » progenitor cells. Further, A-674563 decreased sphingosine kinase 1 (SphK1) activity in above AML cells to deplete pro-survival sphingosine-1-phosphate (S1P) and boost pro-apoptotic ceramide production. Such an effect on SphK1 signaling by A-674563 appeared independent of Akt blockage. Significantly, K6PC-5, a novel SphK1 activator, or supplement with S1P attenuated A-674563-induced ceramide production, and subsequent U937 cell death and apoptosis. Importantly, intraperitoneal injection of A-674563 at well-tolerated doses suppressed U937 leukemic xenograft tumor growth in nude mice, whiling significantly improving the animal survival. The results of the current study demonstrate that A-674563 exerts potent anti-leukemic activity in vitro and in vivo, possibly via concurrent targeting Akt and SphK1 signalings. - Highlights: • A-674563 is cytotoxic and anti-proliferative in U937 and AML progenitor cells. • A-674563 activates caspase-3/9 and apoptosis in U937 and AML progenitor cells. • Whiling blocking Akt, A-674563 manipulates other signalings in AML cells. • A-674563 inhibits SphK1 activity in AML cells, independent of Akt blockage. • A-674563 injection inhibits U937 xenograft in vivo growth, and improves mice survival.« less

Choline Magnesium Trisalicylate and Combination Chemotherapy in Treating Patients With Acute Myeloid Leukemia

ClinicalTrials.gov

2017-02-01

Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Recurrent Adult Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Hematopoietic Colony Formation from Human Growth Factor-Dependent TF1 Cells and Human Cord Blood Myeloid Progenitor Cells Depends on SHP2 Phosphatase Function

PubMed Central

Etienne-Julan, Maryse; Gotoh, Akihiko; Braun, Stephen E.; Lu, Li; Cooper, Scott; Feng, Gen-Sheng; Li, Xing Jun

2013-01-01

The protein tyrosine phosphatase, SHP2, is widely expressed; however, previous studies demonstrated that hematopoietic cell development more stringently requires Shp2 expression compared to other tissues. Furthermore, somatic gain-of-function SHP2 mutants are commonly found in human myeloid leukemias. Given that pharmacologic inhibitors to SHP2 phosphatase activity are currently in development as putative antileukemic agents, we conducted a series of experiments examining the necessity of SHP2 phosphatase activity for human hematopoiesis. Anti-sense oligonucleotides to human SHP2 coding sequences reduced human cord blood- and human cell line, TF1-derived colony formation. Expression of truncated SHP2 bearing its Src homology 2 (SH2) domains, but lacking the phosphatase domain similarly reduced human cord blood- and TF1-derived colony formation. Mechanistically, expression of truncated SHP2 reduced the interaction between endogenous, full-length SHP2 with the adapter protein, Grb2. To verify the role of SHP2 phosphatase function in human hematopoietic cell development, human cord blood CD34+ cells were transduced with a leukemia-associated phosphatase gain-of-function SHP2 mutant or with a phosphatase dead SHP2 mutant, which indicated that increased phosphatase function enhanced, while decreased SHP2 phosphatase function reduced, human cord blood-derived colonies. Collectively, these findings indicate that SHP2 phosphatase function regulates human hematopoietic cell development and imply that the phosphatase component of SHP2 may serve as a pharmacologic target in human leukemias bearing increased SHP2 phosphatase activity. PMID:23082805

Implications of Mutation Profiling in Myeloid Malignancies-PART 2: Myeloproliferative Neoplasms and Other Myeloid Malignancies.

PubMed

Sokol, Kelsey; Tremblay, Douglas; Bhalla, Sheena; Rampal, Raajit; Mascarenhas, John O

2018-05-15

Myeloid malignancies arise from the acquisition of somatic mutations among various genes implicated in essential functioning of hematopoietic stem cells and progenitor cells. In this second part of our two-part review, we discuss the use of mutation profiling in the diagnosis, prognosis, and treatment of patients with myeloproliferative neoplasms and other myeloid diseases. We also discuss the entity known as clonal hematopoiesis of indeterminate potential, awareness of which is a result of the increasing availability and improved quality of mutation profiling.

Genomic Flexibility of Human Endogenous Retrovirus Type K

PubMed Central

Dube, Derek; Contreras-Galindo, Rafael; He, Shirley; King, Steven R.; Gonzalez-Hernandez, Marta J.; Gitlin, Scott D.; Kaplan, Mark H.

2014-01-01

ABSTRACT Human endogenous retrovirus type K (HERV-K) proviruses are scattered throughout the human genome, but as no infectious HERV-K virus has been detected to date, the mechanism by which these viruses replicated and populated the genome remains unresolved. Here, we provide evidence that, in addition to the RNA genomes that canonical retroviruses package, modern HERV-K viruses can contain reverse-transcribed DNA (RT-DNA) genomes. Indeed, reverse transcription of genomic HERV-K RNA into the DNA form is able to occur in three distinct times and locations: (i) in the virus-producing cell prior to viral release, yielding a DNA-containing extracellular virus particle similar to the spumaviruses; (ii) within the extracellular virus particle itself, transitioning from an RNA-containing particle to a DNA-containing particle; and (iii) after entry of the RNA-containing virus into the target cell, similar to canonical retroviruses, such as murine leukemia virus and HIV. Moreover, using a resuscitated HERV-K virus construct, we show that both viruses with RNA genomes and viruses with DNA genomes are capable of infecting target cells. This high level of genomic flexibility historically could have permitted these viruses to replicate in various host cell environments, potentially assisting in their many integration events and resulting in their high prevalence in the human genome. Moreover, the ability of modern HERV-K viruses to proceed through reverse transcription and package RT-DNA genomes suggests a higher level of replication competency than was previously understood, and it may be relevant in HERV-K-associated human diseases. IMPORTANCE Retroviral elements comprise at least 8% of the human genome. Of all the endogenous retroviruses, HERV-K viruses are the most intact and biologically active. While a modern infectious HERV-K has yet to be found, HERV-K activation has been associated with cancers, autoimmune diseases, and HIV-1 infection. Thus, determining how this

Mechanosensitive cation channels in human leukaemia cells: calcium permeation and blocking effect

PubMed Central

Staruschenko, Alexandr V; Vedernikova, Elena A

2002-01-01

Cell-attached and inside-out patch-clamp methods were employed to identify and characterize mechanosensitive (MS) ionic channels in the plasma membrane of human myeloid leukaemia K562 cells. A reversible activation of gadolinium-blockable mechanogated currents in response to negative pressure application was found in 58 % of stable patches (n = 317). I-V relationships measured with a sodium-containing pipette solution showed slight inward rectification. Data analysis revealed the presence of two different populations of channels that were distinguishable by their conductance properties (17.2 ± 0.3 pS and 24.5 ± 0.5 pS), but were indistinguishable with regard to their selective and pharmacological properties. Ion-substitution experiments indicated that MS channels in leukaemia cells were permeable to cations but not to anions and do not discriminate between Na+ and K+. The channels were fully impermeable to large organic cations such as Tris+ and N-methyl-d-glucamine ions (NMDG+). Ca2+ permeation and blockade of MS channels were examined using pipettes containing different concentrations of Ca2+. In the presence of 2 mm CaCl2, when other cations were impermeant, both outward and inward single-channel currents were observed; the I-V relationship showed a unitary conductance of 7.7 ± 1.0 pS. The relative permeability value, PCa/PK, was equal to 0.75, as estimated at physiological Ca2+ concentrations. Partial or full inhibition of inward Ca2+ currents through MS channels was observed at higher concentrations of external Ca2+ (10 or 20 mm). No MS channels were activated when using a pipette containing 90 mm CaCl2. Monovalent mechanogated currents were not significantly affected by extracellular Ca2+ at concentrations within the physiological range (0-2 mm), and at some higher Ca2+ concentrations. PMID:12015421

8-Chloro-Adenosine in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

ClinicalTrials.gov

2018-01-30

Recurrent Adult Acute Myeloid Leukemia; Relapsed Adult Acute Myeloid Leukemia; Acute Myeloid Leukemia Arising From Previous Myelodysplastic Syndrome; Acute Myeloid Leukemia Arising From Previous Myeloproliferative Disorder

Haploinsufficiency for DNA methyltransferase 3A predisposes hematopoietic cells to myeloid malignancies

PubMed Central

Cole, Christopher B.; Russler-Germain, David A.; Ketkar, Shamika; Verdoni, Angela M.; Smith, Amanda M.; Bangert, Celia V.; Helton, Nichole M.; Guo, Mindy; O’Laughlin, Shelly; Fronick, Catrina; Fulton, Robert; Chang, Gue Su; Petti, Allegra A.; Miller, Christopher A.; Ley, Timothy J.

2017-01-01

The gene that encodes de novo DNA methyltransferase 3A (DNMT3A) is frequently mutated in acute myeloid leukemia genomes. Point mutations at position R882 have been shown to cause a dominant negative loss of DNMT3A methylation activity, but 15% of DNMT3A mutations are predicted to produce truncated proteins that could either have dominant negative activities or cause loss of function and haploinsufficiency. Here, we demonstrate that 3 of these mutants produce truncated, inactive proteins that do not dimerize with WT DNMT3A, strongly supporting the haploinsufficiency hypothesis. We therefore evaluated hematopoiesis in mice heterozygous for a constitutive null Dnmt3a mutation. With no other manipulations, Dnmt3a+/– mice developed myeloid skewing over time, and their hematopoietic stem/progenitor cells exhibited a long-term competitive transplantation advantage. Dnmt3a+/– mice also spontaneously developed transplantable myeloid malignancies after a long latent period, and 3 of 12 tumors tested had cooperating mutations in the Ras/MAPK pathway. The residual Dnmt3a allele was neither mutated nor downregulated in these tumors. The bone marrow cells of Dnmt3a+/– mice had a subtle but statistically significant DNA hypomethylation phenotype that was not associated with gene dysregulation. These data demonstrate that haploinsufficiency for Dnmt3a alters hematopoiesis and predisposes mice (and probably humans) to myeloid malignancies by a mechanism that is not yet clear. PMID:28872462

Arsenic Trioxide in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

ClinicalTrials.gov

2018-05-16

Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Recurrent Adult Acute Myeloid Leukemia

Leaf extracts from Moricandia arvensis promote antiproliferation of human cancer cells, induce apoptosis, and enhance antioxidant activity.

PubMed

Skandrani, Ines; Boubaker, Jihed; Bhouri, Wissem; Limem, Ilef; Kilani, Soumaya; Ben Sghaier, Mohamed; Neffati, Aicha; Bouhlel, Ines; Ghedira, Kamel; Chekir-Ghedira, Leila

2010-01-01

The in vitro antiproliferative, apoptotic, and antioxidant activities from leaf extracts of Moricandia arvensis, which are used in traditional cooking and medicines, were investigated. The MTT assay revealed that only TOF (total oligomer flavonoids), ethyl acetate (EA), chloroform (Chl), and petroleum ether (PE) extracts inhibited the proliferation of K562 cells. Apoptosis plays a very important role in the treatment of cancer by promoting the apoptosis of cancer cells and limiting the concurrent death of normal cells. Thus, the possible effects of M. arvensis extracts on the induction of apoptosis in human leukemic cells (K562 cells) were investigated. The electrophoretic analysis of DNA fragmentation confirms that TOF, Chl, PE, and EA extracts provoke DNA fragmentation. Using the lipid peroxidation inhibitory assay, the antioxidant capacity of M. arvensis extracts was evaluated by the ability of each extract to inhibit malondialdehyde formation. It was revealed that EA and TOF extracts are the most active in scavenging the hydroxyl radicals.

HIV persistence in tissue macrophages of humanized myeloid-only mice during antiretroviral therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Honeycutt, Jenna B.; Thayer, William O.; Baker, Caroline E.

Despite years of fully suppressive antiretroviral therapy (ART), HIV persists in its hosts and is never eradicated. One major barrier to eradication is that the virus infects multiple cell types that may individually contribute to HIV persistence. Tissue macrophages are critical contributors to HIV pathogenesis; however, their specific role in HIV persistence during long-term suppressive ART has not been established. Using humanized myeloid-only mice (MoM), we demonstrate that HIV infection of tissue macrophages is rapidly suppressed by ART, as reflected by a rapid drop in plasma viral load and a dramatic decrease in the levels of cell-associated viral RNA andmore » DNA. No viral rebound was observed in the plasma of 67% of the ART-treated animals at 7 weeks after ART interruption, and no replication-competent virus was rescued from the tissue macrophages obtained from these animals. In contrast, in a subset of animals (~33%), a delayed viral rebound was observed that is consistent with the establishment of persistent infection in tissue macrophages. Furthermore, these observations represent the first direct evidence, to our knowledge, of HIV persistence in tissue macrophages in vivo.« less

HIV persistence in tissue macrophages of humanized myeloid-only mice during antiretroviral therapy

DOE PAGES

Honeycutt, Jenna B.; Thayer, William O.; Baker, Caroline E.; ...

2017-04-17

Despite years of fully suppressive antiretroviral therapy (ART), HIV persists in its hosts and is never eradicated. One major barrier to eradication is that the virus infects multiple cell types that may individually contribute to HIV persistence. Tissue macrophages are critical contributors to HIV pathogenesis; however, their specific role in HIV persistence during long-term suppressive ART has not been established. Using humanized myeloid-only mice (MoM), we demonstrate that HIV infection of tissue macrophages is rapidly suppressed by ART, as reflected by a rapid drop in plasma viral load and a dramatic decrease in the levels of cell-associated viral RNA andmore » DNA. No viral rebound was observed in the plasma of 67% of the ART-treated animals at 7 weeks after ART interruption, and no replication-competent virus was rescued from the tissue macrophages obtained from these animals. In contrast, in a subset of animals (~33%), a delayed viral rebound was observed that is consistent with the establishment of persistent infection in tissue macrophages. Furthermore, these observations represent the first direct evidence, to our knowledge, of HIV persistence in tissue macrophages in vivo.« less

HIV persistence in tissue macrophages of humanized myeloid only mice during antiretroviral therapy

PubMed Central

Honeycutt, J. B.; Thayer, W.O.; Baker, C. E.; Ribeiro, R.M.; Lada, S.M.; Cao, Y.; Cleary, R. A.; Hudgens, M. G.; Richman, D.D.; Garcia, J. V.

2017-01-01

Despite years of fully suppressive antiretroviral therapy (ART), HIV persists in the host and is never eradicated. One major barrier to eradication is that multiple different cell types are infected that may individually contribute to HIV persistence. Tissue macrophages are critical contributors to HIV disease (1–3); however, their specific role in HIV persistence during long-term suppressive ART has not been established (4–6). Using humanized myeloid-only mice (MoM), we demonstrate that HIV infection of tissue macrophages is rapidly suppressed by ART, as determined by a rapid drop in plasma viral load and a dramatic drop in the levels of cell-associated viral RNA and DNA. No virus rebound was observed in the plasma of 67% of the ART treated animals at seven weeks post-ART interruption, and no replication competent virus was rescued from the tissue macrophages obtained from these animals. In contrast, in a subset of animals (~33%), a significantly delayed viral rebound was observed that is consistent with the establishment of persistent infection in tissue macrophages. These observations represent the first direct evidence of HIV persistence in tissue macrophages in vivo. PMID:28414330

HIV persistence in tissue macrophages of humanized myeloid-only mice during antiretroviral therapy.

PubMed

Honeycutt, Jenna B; Thayer, William O; Baker, Caroline E; Ribeiro, Ruy M; Lada, Steven M; Cao, Youfang; Cleary, Rachel A; Hudgens, Michael G; Richman, Douglas D; Garcia, J Victor

2017-05-01

Despite years of fully suppressive antiretroviral therapy (ART), HIV persists in its hosts and is never eradicated. One major barrier to eradication is that the virus infects multiple cell types that may individually contribute to HIV persistence. Tissue macrophages are critical contributors to HIV pathogenesis; however, their specific role in HIV persistence during long-term suppressive ART has not been established. Using humanized myeloid-only mice (MoM), we demonstrate that HIV infection of tissue macrophages is rapidly suppressed by ART, as reflected by a rapid drop in plasma viral load and a dramatic decrease in the levels of cell-associated viral RNA and DNA. No viral rebound was observed in the plasma of 67% of the ART-treated animals at 7 weeks after ART interruption, and no replication-competent virus was rescued from the tissue macrophages obtained from these animals. In contrast, in a subset of animals (∼33%), a delayed viral rebound was observed that is consistent with the establishment of persistent infection in tissue macrophages. These observations represent the first direct evidence, to our knowledge, of HIV persistence in tissue macrophages in vivo.

Activation of human T-helper/inducer cell, T-cytotoxic/suppressor cell, B-cell, and natural killer (NK)-cells and induction of NK cell activity against K562 chronic myeloid leukemia cells with modified citrus pectin

USDA-ARS?s Scientific Manuscript database

Background Modified citrus pectin (MCP) is known for its anti-cancer effects and its ability to be absorbed and circulated in the human body. In this report we tested the ability of MCP to induce the activation of human blood lymphocyte subsets including T-helper/inducer cell, Tcytotoxic/suppres...

Myeloid-derived suppressor cells modulate B-cell responses.

PubMed

Lelis, Felipe J N; Jaufmann, Jennifer; Singh, Anurag; Fromm, Katja; Teschner, Annkathrin Chiara; Pöschel, Simone; Schäfer, Iris; Beer-Hammer, Sandra; Rieber, Nikolaus; Hartl, Dominik

2017-08-01

Myeloid-derived suppressor cells (MDSCs) are key regulators of adaptive immunity by suppressing T-cell functions. However, their potential action on or interaction with B cells remained poorly understood. Here we demonstrate that human polymorphonuclear MDSCs differentially modulate B-cell function by suppressing B-cell proliferation and antibody production. We further demonstrate that this MDSC-mediated effect is cell contact dependent and involves established mediators such as arginase-1, nitric oxide (NO), reactive oxygen species (ROS) as well as B-cell death. Collectively, our studies provide novel evidence that human MDSCs modulate B cells, which could have future implications for immunotherapy approaches. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Minimal PU.1 reduction induces a preleukemic state and promotes development of acute myeloid leukemia

PubMed Central

Will, Britta; Vogler, Thomas O.; Narayanagari, Swathi; Bartholdy, Boris; Todorova, Tihomira I.; da Silva Ferreira, Mariana; Chen, Jiahao; Yu, Yiting; Mayer, Jillian; Barreyro, Laura; Carvajal, Luis; Ben Neriah, Daniela; Roth, Michael; van Oers, Johanna; Schaetzlein, Sonja; McMahon, Christine; Edelmann, Winfried; Verma, Amit; Steidl, Ulrich

2016-01-01

Modest transcriptional changes caused by genetic or epigenetic mechanisms are frequent in human cancer. Although loss or near-complete loss of the hematopoietic transcription factor PU.1 induces acute myeloid leukemia (AML) in mice, a similar degree of PU.1 impairment is exceedingly rare in human AML; yet moderate PU.1 inhibition is common in AML patients. We assessed functional consequences of modest reduction of PU.1 expression on leukemia development in mice harboring DNA lesions resembling those acquired during human stem cell aging. Heterozygous deletion of an enhancer of PU.1, which resulted in 35% reduction of PU.1 expression, was sufficient to induce myeloid biased preleukemic stem cells and subsequent transformation to AML in a DNA mismatch repair-deficient background. AML progression was mediated by inhibition of expression of a PU.1 cooperating transcription factor, Irf8. Strikingly, we found significant molecular similarities with human myelodysplastic syndrome and AML. This study demonstrates that minimal reduction of a key lineage-specific transcription factor that commonly occurs in human disease is sufficient to initiate cancer development and provides mechanistic insight into the formation and progression of preleukemic stem cells in AML. PMID:26343801

Azacitidine and Gemtuzumab Ozogamicin in Treating Older Patients With Previously Untreated Acute Myeloid Leukemia

ClinicalTrials.gov

2018-04-20

Acute Myeloid Leukemia; Adult Acute Megakaryoblastic Leukemia; Adult Acute Monoblastic Leukemia; Adult Acute Monocytic Leukemia; Adult Acute Myeloid Leukemia With Inv(16)(p13.1q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With Maturation; Adult Acute Myeloid Leukemia With t(16;16)(p13.1;q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With t(8;21); (q22; q22.1); RUNX1-RUNX1T1; Adult Acute Myeloid Leukemia With t(9;11)(p22.3;q23.3); MLLT3-KMT2A; Adult Acute Myeloid Leukemia Without Maturation; Adult Acute Myelomonocytic Leukemia; Adult Erythroleukemia; Adult Pure Erythroid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Effects of antioxidants on apoptosis induced by dasatinib and nilotinib in K562 cells.

PubMed

Damiano, Sara; Montagnaro, Serena; Puzio, Maria V; Severino, Lorella; Pagnini, Ugo; Barbarino, Marcella; Cesari, Daniele; Giordano, Antonio; Florio, Salvatore; Ciarcia, Roberto

2018-06-01

In clinical practice for the treatment of chronic myeloid leukemia, second generation of tyrosine kinase inhibitors such as Nilotinib (NIL) specific and potent inhibitor of the BCR/ABL kinase and Dasatinib (DAS) a inhibitor of BCR/ABL and Src family kinase were developed to clinically overcome imatinib resistance. In this study, we wanted to test the ability of some antioxidants such Resveratrol (RES) or a new recombinant mitochondrial manganese containing superoxide dismutase (rMnSOD) or δ-tocotrienol (δ-TOCO) to interact with DAS and NIL on viability, reactive oxygen species (ROS) production, lipid peroxidation, and apoptosis. To test the possible mechanisms of action of such antioxidants, we utilized N-acetyl-L-cysteine (NAC) a specific inhibitor ROS production or PP1 a specific Src tyrosine kinase inhibitor or BAPTA a specific chelator of intracellular calcium. Our data demonstrated: 1) RES, rMnSOD, δ-TOCO, and NAC, at dose used, significantly reduced the intracellular levels of MDA induced by DAS or NIL; 2) RES, rMnSOD, and δ-TOCO increased the intracellular ROS levels; 3) The increase ROS levels is related to higher levels of oligonucleosomesi induced by DAS and NIL and that NAC significantly reduced this activity. Interestingly, our data showed that apoptotic activity of DAS and NIL have significantly increased the production of oligonucleosomes by triggering excessive ROS generation as well as functionality of SERCA receptors. © 2018 Wiley Periodicals, Inc.

Myeloid Wnt ligands are required for normal development of dermal lymphatic vasculature.

PubMed

Muley, Ajit; Odaka, Yoshi; Lewkowich, Ian P; Vemaraju, Shruti; Yamaguchi, Terry P; Shawber, Carrie; Dickie, Belinda H; Lang, Richard A

2017-01-01

Resident tissue myeloid cells play a role in many aspects of physiology including development of the vascular systems. In the blood vasculature, myeloid cells use VEGFC to promote angiogenesis and can use Wnt ligands to control vascular branching and to promote vascular regression. Here we show that myeloid cells also regulate development of the dermal lymphatic vasculature using Wnt ligands. Using myeloid-specific deletion of the WNT transporter Wntless we show that myeloid Wnt ligands are active at two distinct stages of development of the dermal lymphatics. As lymphatic progenitors are emigrating from the cardinal vein and intersomitic vessels, myeloid Wnt ligands regulate both their numbers and migration distance. Later in lymphatic development, myeloid Wnt ligands regulate proliferation of lymphatic endothelial cells (LEC) and thus control lymphatic vessel caliber. Myeloid-specific deletion of WNT co-receptor Lrp5 or Wnt5a gain-of-function also produce elevated caliber in dermal lymphatic capillaries. These data thus suggest that myeloid cells produce Wnt ligands to regulate lymphatic development and use Wnt pathway co-receptors to regulate the balance of Wnt ligand activity during the macrophage-LEC interaction.

Enhancing Natural Killer Cell Mediated Targeting and Responses to Myeloid Leukemias

DTIC Science & Technology

2017-10-01

Syndromes , AML – Acute Myeloid Leukemia, BiKE – Bi-specific Killer Engager, TriKE – Tri-specific Killer E 16. SECURITY CLASSIFICATION OF: 17...Natural Killer CML – Chronic Myeloid Leukemia MDS – Myelodysplastic Syndromes AML – Acute Myeloid Leukemia BiKE – Bi-specific Killer Engager TriKE...incidence of myeloid malignancies is increased due to exposure to ionizing radiation , chemicals, and other agents during deployment. Although

Genetics Home Reference: cytogenetically normal acute myeloid leukemia

MedlinePlus

... on PubMed Marcucci G, Haferlach T, Döhner H. Molecular genetics of adult acute myeloid leukemia: prognostic and therapeutic ... on PubMed Sanders MA, Valk PJ. The evolving molecular genetic landscape in acute myeloid leukaemia. Curr Opin Hematol. ...

Human IgG2 antibodies against epidermal growth factor receptor effectively trigger antibody-dependent cellular cytotoxicity but, in contrast to IgG1, only by cells of myeloid lineage.

PubMed

Schneider-Merck, Tanja; Lammerts van Bueren, Jeroen J; Berger, Sven; Rossen, Kai; van Berkel, Patrick H C; Derer, Stefanie; Beyer, Thomas; Lohse, Stefan; Bleeker, Wim K; Peipp, Matthias; Parren, Paul W H I; van de Winkel, Jan G J; Valerius, Thomas; Dechant, Michael

2010-01-01

Ab-dependent cellular cytotoxicity (ADCC) is usually considered an important mechanism of action for immunotherapy with human IgG1 but not IgG2 Abs. The epidermal growth factor receptor (EGF-R) Ab panitumumab represents the only human IgG2 Ab approved for immunotherapy and inhibition of EGF-R signaling has been described as its principal mechanism of action. In this study, we investigated effector mechanisms of panitumumab compared with zalutumumab, an EGF-R Ab of the human IgG1 isotype. Notably, panitumumab was as effective as zalutumumab in recruiting ADCC by myeloid effector cells (i.e., neutrophils and monocytes) in contrast to NK cell-mediated ADCC, which was only induced by the IgG1 Ab. Neutrophil-mediated tumor cell killing could be stimulated by myeloid growth factors and was triggered via FcgammaRIIa. Panitumumab-mediated ADCC was significantly affected by the functional FcgammaRIIa-R131H polymorphism and was induced more effectively by neutrophils from FcgammaRIIa-131H homozygous donors than from -131R individuals. This polymorphism did not affect neutrophil ADCC induced by the IgG1 Ab zalutumumab. The in vivo activity of both Abs was assessed in two animal models: a high-dose model, in which signaling inhibition is a dominant mechanism of action, and a low-dose model, in which effector cell recruitment plays a prominent role. Zalutumumab was more effective than panitumumab in the high-dose model, reflecting its stronger ability to induce EGF-R downmodulation and growth inhibition. In the low-dose model, zalutumumab and panitumumab similarly prevented tumor growth. Thus, our results identify myeloid cell-mediated ADCC as a potent and additional mechanism of action for EGF-R-directed immunotherapy.

Azacitidine and Sonidegib or Decitabine in Treating Patients With Myeloid Malignancies

ClinicalTrials.gov

2018-02-05

Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndrome; Essential Thrombocythemia; Myelodysplastic Syndrome; Myelodysplastic/Myeloproliferative Neoplasm; Polycythemia Vera; Previously Treated Myelodysplastic Syndrome; Primary Myelofibrosis; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

SNP array analysis of tyrosine kinase inhibitor-resistant chronic myeloid leukemia identifies heterogeneous secondary genomic alterations

PubMed Central

Müschen, Markus; Kato, Motohiro; Kawamata, Norihiko; Meixel, Antonie; Nowak, Verena; Kim, Han S.; Kang, Sharon; Paquette, Ronald; Chang, Mi-Sook; Thoenissen, Nils H.; Mossner, Max; Hofmann, Wolf-Karsten; Kohlmann, Alexander; Weiss, Tamara; Haferlach, Torsten; Haferlach, Claudia; Koeffler, H. Phillip

2010-01-01

To elucidate whether tyrosine kinase inhibitor (TKI) resistance in chronic myeloid leukemia is associated with characteristic genomic alterations, we analyzed DNA samples from 45 TKI-resistant chronic myeloid leukemia patients with 250K single nucleotide polymorphism arrays. From 20 patients, matched serial samples of pretreatment and TKI resistance time points were available. Eleven of the 45 TKI-resistant patients had mutations of BCR-ABL1, including 2 T315I mutations. Besides known TKI resistance-associated genomic lesions, such as duplication of the BCR-ABL1 gene (n = 8) and trisomy 8 (n = 3), recurrent submicroscopic alterations, including acquired uniparental disomy, were detectable on chromosomes 1, 8, 9, 17, 19, and 22. On chromosome 22, newly acquired and recurrent deletions of the IGLC1 locus were detected in 3 patients, who had previously presented with lymphoid or myeloid blast crisis. This may support a hypothesis of TKI-induced selection of subclones differentiating into immature B-cell progenitors as a mechanism of disease progression and evasion of TKI sensitivity. PMID:19965645

Azacitidine, Cytarabine, and Mitoxantrone Hydrochloride in Treating Patients With High-Risk Acute Myeloid Leukemia

ClinicalTrials.gov

2018-01-02

Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia in Remission; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Recurrent Adult Acute Myeloid Leukemia; Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

cDNA cloning, tissue distribution, and chromosomal localization of myelodysplasia/myeloid leukemia factor 2 (MLF2).

PubMed

Kuefer, M U; Look, A T; Williams, D C; Valentine, V; Naeve, C W; Behm, F G; Mullersman, J E; Yoneda-Kato, N; Montgomery, K; Kucherlapati, R; Morris, S W

1996-07-15

A fusion gene between nucleophosmin (NPM) and myelodysplasia/myeloid leukemia factor 1 (MLF1) is formed by a recurrent t(3;5)(q25.1;q34) in myelodysplastic syndrome and acute myeloid leukemia. Here we report the identification of a novel gene, MLF2, which contains an open reading frame of 744 bp encoding a 248-amino-acid protein highly related to the previously identified MLF1 protein (63% similarity, 40% identity). In contrast to the tissue-restricted expression pattern of MLF1, the MLF2 messenger RNA is expressed ubiquitously. The MLF2 gene locus was mapped by fluorescence in situ hybridization to human chromosome 12p13, a chromosomal region frequently involved in translocations and deletions in acute leukemias of lymphoid or myeloid lineage. In a physical map of chromosome 12, MLF2 was found to reside on the yeast artificial chromosome clone 765b9. Southern blotting analysis of malignant cell DNAs prepared from a series of acute lymphoblastic leukemia cases with translocations involving chromosome arm 12p, as well as a group of acute myeloid leukemias with various cytogenetic abnormalities, failed to reveal MLF2 gene rearrangements.

40 CFR 141.562 - My system only has two or fewer filters-is there any special provision regarding individual...

Code of Federal Regulations, 2012 CFR

2012-07-01

... filters-is there any special provision regarding individual filter turbidity monitoring? 141.562 Section... Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.562 My system only has two or fewer filters—is there any special provision regarding individual filter turbidity monitoring? Yes, if...

40 CFR 141.562 - My system only has two or fewer filters-is there any special provision regarding individual...

Code of Federal Regulations, 2014 CFR

2014-07-01

... filters-is there any special provision regarding individual filter turbidity monitoring? 141.562 Section... Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.562 My system only has two or fewer filters—is there any special provision regarding individual filter turbidity monitoring? Yes, if...

40 CFR 141.562 - My system only has two or fewer filters-is there any special provision regarding individual...

Code of Federal Regulations, 2010 CFR

2010-07-01

... filters-is there any special provision regarding individual filter turbidity monitoring? 141.562 Section... Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.562 My system only has two or fewer filters—is there any special provision regarding individual filter turbidity monitoring? Yes, if...

40 CFR 141.562 - My system only has two or fewer filters-is there any special provision regarding individual...

Code of Federal Regulations, 2011 CFR

2011-07-01

... filters-is there any special provision regarding individual filter turbidity monitoring? 141.562 Section... Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.562 My system only has two or fewer filters—is there any special provision regarding individual filter turbidity monitoring? Yes, if...

40 CFR 141.562 - My system only has two or fewer filters-is there any special provision regarding individual...

Code of Federal Regulations, 2013 CFR

2013-07-01

... filters-is there any special provision regarding individual filter turbidity monitoring? 141.562 Section... Fewer Than 10,000 People Individual Filter Turbidity Requirements § 141.562 My system only has two or fewer filters—is there any special provision regarding individual filter turbidity monitoring? Yes, if...

Overexpression of P-glycoprotein induces acquired resistance to imatinib in chronic myelogenous leukemia cells

PubMed Central

Peng, Xing-Xiang; Tiwari, Amit K.; Wu, Hsiang-Chun; Chen, Zhe-Sheng

2012-01-01

Imatinib, a breakpoint cluster region (BCR)-Abelson murine leukemia (ABL) tyrosine kinase inhibitor (TKI), has revolutionized the treatment of chronic myelogenous leukemia (CML). However, development of multidrug resistance (MDR) limits the use of imatinib. In the present study, we aimed to investigate the mechanisms of cellular resistance to imatinib in CML. Therefore, we established an imatinib-resistant human CML cell line (K562-imatinib) through a stepwise selection process. While characterizing the phenotype of these cells, we found that K562-imatinib cells were 124.6-fold more resistant to imatinib than parental K562 cells. In addition, these cells were cross-resistant to second- and third-generation BCR-ABL TKIs. Western blot analysis and reverse transcription-polymerase chain reaction(RT-PCR) demonstrated that P-glycoprotein (P-gp) and MDR1 mRNA levels were increased in K562-imatinib cells. In addition, accumulation of [14C]6-mercaptopurine (6-MP) was decreased, whereas the ATP-dependent efflux of [14C] 6-MP and [3H]methotrexate transport were increased in K562-imatinib cells. These data suggest that the overexpression of P-gp may play a crucial role in acquired resistance to imatinib in CML K562-imatinib cells. PMID:22098951

Cholecalciferol in Treating Patients With Acute Myeloid Leukemia Undergoing Intensive Induction Chemotherapy

ClinicalTrials.gov

2015-06-18

Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Untreated Adult Acute Myeloid Leukemia

Tipifarnib and Etoposide in Treating Older Patients With Newly Diagnosed Acute Myeloid Leukemia

ClinicalTrials.gov

2013-01-08

Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Secondary Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Knockdown of miR-128a induces Lin28a expression and reverts myeloid differentiation blockage in acute myeloid leukemia

PubMed Central

De Luca, Luciana; Trino, Stefania; Laurenzana, Ilaria; Tagliaferri, Daniela; Falco, Geppino; Grieco, Vitina; Bianchino, Gabriella; Nozza, Filomena; Campia, Valentina; D'Alessio, Francesca; La Rocca, Francesco; Caivano, Antonella; Villani, Oreste; Cilloni, Daniela; Musto, Pellegrino; Del Vecchio, Luigi

2017-01-01

Lin28A is a highly conserved RNA-binding protein that concurs to control the balance between stemness and differentiation in several tissue lineages. Here, we report the role of miR-128a/Lin28A axis in blocking cell differentiation in acute myeloid leukemia (AML), a genetically heterogeneous disease characterized by abnormally controlled proliferation of myeloid progenitor cells accompanied by partial or total inability to undergo terminal differentiation. First, we found Lin28A underexpressed in blast cells from AML patients and AML cell lines as compared with CD34+ normal precursors. In vitro transfection of Lin28A in NPM1-mutated OCI-AML3 cell line significantly triggered cell-cycle arrest and myeloid differentiation, with increased expression of macrophage associate genes (EGR2, ZFP36 and ANXA1). Furthermore, miR-128a, a negative regulator of Lin28A, was found overexpressed in AML cells compared with normal precursors, especially in acute promyelocytic leukemia (APL) and in ‘AML with maturation’ (according to 2016 WHO classification of myeloid neoplasms and acute leukemia). Its forced overexpression by lentiviral infection in OCI-AML3 downregulated Lin28A with ensuing repression of macrophage-oriented differentiation. Finally, knockdown of miR-128a in OCI-AML3 and in APL/AML leukemic cells (by transfection and lentiviral infection, respectively) induced myeloid cell differentiation and increased expression of Lin28A, EGR2, ZFP36 and ANXA1, reverting myeloid differentiation blockage. In conclusion, our findings revealed a new mechanism for AML differentiation blockage, suggesting new strategies for AML therapy based upon miR-128a inhibition. PMID:28569789

Activity of Bruton's tyrosine-kinase inhibitor ibrutinib in patients with CD117-positive acute myeloid leukaemia: a mechanistic study using patient-derived blast cells.

PubMed

Rushworth, Stuart A; Pillinger, Genevra; Abdul-Aziz, Amina; Piddock, Rachel; Shafat, Manar S; Murray, Megan Y; Zaitseva, Lyubov; Lawes, Matthew J; MacEwan, David J; Bowles, Kristian M

2015-05-01

Roughly 80% of patients with acute myeloid leukaemia have high activity of Bruton's tyrosine-kinase (BTK) in their blast cells compared with normal haemopoietic cells, rendering the cells sensitive to the oral BTK inhibitor ibrutinib in vitro. We aimed to develop the biological understanding of the BTK pathway in acute myeloid leukaemia to identify clinically relevant diagnostic information that might define a subset of patients that should respond to ibrutinib treatment. We obtained acute myeloid leukaemia blast cells from unselected patients attending our UK hospital between Feb 19, 2010, and Jan 20, 2014. We isolated primary acute myeloid leukaemia blast cells from heparinised blood and human peripheral blood mononuclear cells to establish the activity of BTK in response to CD117 activation. Furthermore, we investigated the effects of ibrutinib on CD117-induced BTK activation, downstream signalling, adhesion to primary bone-marrow mesenchymal stromal cells, and proliferation of primary acute myeloid leukaemia blast cells. We used the Mann-Whitney U test to compare results between groups. We obtained acute myeloid leukaemia blast cells from 29 patients. Ibrutinib significantly inhibited CD117-mediated proliferation of primary acute myeloid leukaemia blast cells (p=0·028). CD117 activation increased BTK activity by inducing phosphorylated BTK in patients with CD117-positive acute myeloid leukaemia. Furthermore, ibrutinib inhibited CD117-induced activity of BTK and downstream kinases at a concentration of 100 nM or more. CD117-mediated adhesion of CD117-expressing blast cells to bone-marrow stromal cells was significantly inhibited by Ibrutinib at 500 nM (p=0·028) INTERPRETATION: As first-in-man clinical trials of ibrutinib in patients with acute myeloid leukaemia commence, the data suggest not all patients will respond. Our findings show that BTK has specific pro-tumoural biological actions downstream of surface CD117 activation, which are inhibited by ibrutinib

Molecular cloning and characterization of markers and cytokines for equid myeloid cells.

PubMed

Steinbach, Falko; Stark, Robert; Ibrahim, Sherif; Gawad, Eman Abd-El; Ludwig, Hanns; Walter, Jakob; Commandeur, Ulrich; Mauel, Susanne

2005-10-18

The myeloid cell system comprises of monocytes, macrophages (MPhi), dendritic cells (DC), Kupffer cells, osteoclasts or microglia and is also known as the mononuclear phagocytic system (MPS). Essential cytokines to differentiate or activate these cells include GM-CSF or IL-4. Important markers for characterization include CD1, CD14, CD68, CD163 and CD206. All these markers, however, were not cloned or further characterized in equids by use of monoclonal antibodies earlier. To overcome this problem with the present study, two approaches were used. First, we cloned equine cytokines and markers, and second we analyzed cross-reactivity of human homologues or anti-human monoclonal antibodies. For cloning of equine cytokines and markers, we used degenerate primers delineated from other species, or equine-specific primers based on previous information in Genbank. Flow cytometry was used to determine the expression of markers on myeloid cells. Cross-reactivity could be shown for anti-human CD14, CD163 and mannose receptor (CD206) mAbs. Surface markers such as CD1 and CD68 that distinguish MPhi and DC were cloned and sequenced. According to blast homology, equine CD1a and CD1b could be identified and distinguished. With the resulting information, dendritic cells and macrophages of horses may be characterized.

Do r/K reproductive strategies apply to human differences?

PubMed

Rushton, J P

1988-01-01

This article discusses the r/K theory of Social Biology and how it relates to humans. The symbols r and K originate in the mathematics of population biology and refer to 2 ends of a continuum in which a compensatory exchange occurs between gamete production (the r-strategy) and longevity (the K-strategy). Both across and within species, r and K strategists differ in a suite of correlated characteristics. Humans are the most K of all. K's supposedly have a longer gestation period, a higher birthweight, a more delayed sexual maturation, a lower sex drive, and a longer life. Studies providing evidence for the expected covariation among K attributes are presented. Additional evidence for r/K theory comes from the comparison of human population known to differ in gamete production. The pattern of racial differences observed to occur in sexual behavior has also been found to exist on numerous other indices of K. For instance, there are racial differences in brain size, intelligence, and maturation rate, among others. The findings suggest that, on the average, Mongoloids are more K than Caucasoids, who in turn, are more K than Negroids. Recently conducted studies have extended the data in favor of r/K theory, and further research is currently underway, including whether r/K attributes underlie individual and social class differences in health and longevity.

Clofarabine, Cytarabine, and G-CSF in Treating Patients With Relapsed or Refractory Acute Myeloid Leukemia

ClinicalTrials.gov

2018-02-08

Acute Myeloid Leukemia; Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(15;17)(q22;q12); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Promyelocytic Leukemia (M3); Recurrent Adult Acute Myeloid Leukemia

Childhood Acute Myeloid Leukemia Treatment (PDQ®)—Patient Version

Cancer.gov

Childhood acute myeloid leukemia and other myeloid malignancies treatment may include chemotherapy, radiation therapy, stem cell transplant, and targeted therapy. Learn more about AML and myelodysplastic/myeloproliferative diseases in this expert-reviewed summary.

Trebananib With or Without Low-Dose Cytarabine in Treating Patients With Acute Myeloid Leukemia

ClinicalTrials.gov

2017-02-14

Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Recurrent Adult Acute Myeloid Leukemia; Untreated Adult Acute Myeloid Leukemia

Use of polyclonal anti-myeloperoxidase antibody in myeloid lineage determination.

PubMed

Karnik, M P; Nair, C N; Zingde, S M; Gothoskar, B P; Zachariah, L; Barbhaya, S; Advani, S H

1994-12-01

This study reports the production of a rabbit polyclonal antibody to myeloperoxidase (MPO) and its use in ascertaining the myeloid lineage of blasts in leukaemia. Comparison of the immunocytochemical stain using the anti-MPO antibody with the routine cytochemical methodology showed that the former was more sensitive. In all subtypes of acute myeloid leukaemia (AML; 72 patients, M1-M6) greater number of MPO positive blast cells were observed by immunocytochemistry, the highest being in the promyelocytic leukaemia. It was also extremely specific for cells of the myeloid lineage as it did not react with blasts from acute lymphoblastic (50 patients) and megakaryoblastic leukaemias (1 patient). In addition, it proved most useful for the lineage determination of blasts from patients with undifferentiated acute leukaemias (AUL) and those with chronic myeloid leukaemia in blast crisis (CML-BC). Out of 8 patients of AULs, 6 were classified as acute myeloblastic leukaemia due to their reactivity to the anti-MPO antibody. Similarly, out of 12 patients of chronic myeloid leukaemia in blast crisis, blasts from 8 showed reactivity to this antibody and thus could be identified as belonging to the myeloid lineage and/or of the mixed blast crisis type.

5'-Triphosphate siRNA targeting MDR1 reverses multi-drug resistance and activates RIG-I-induced immune-stimulatory and apoptotic effects against human myeloid leukaemia cells.

PubMed

Li, Dengzhe; Gale, Robert Peter; Liu, Yanfeng; Lei, Baoxia; Wang, Yuan; Diao, Dongmei; Zhang, Mei

2017-07-01

Multi-drug resistance (MDR), immune suppression and decreased apoptosis are important causes of therapy-failure in leukaemia. Short interfering RNAs (siRNAs) down-regulate gene transcription, have sequence-independent immune-stimulatory effects and synergize with other anti-cancer therapies in some experimental models. We designed a siRNA targeting MDR1 with 5'-triphosphate ends (3p-siRNA-MDR1). Treatment of leukaemia cells with 3p-siRNA-MDR1 down-regulated MDR1 expression, reduced-drug resistance and induced immune and pro-apoptotic effects in drug-resistant HL-60/Adr and K562/Adr human leukaemia cell lines. We show mechanisms-of-action of these effects involve alterations in the anti-viral cytosolic retinoic acid-inducible protein-I (RIG-I; encoded by RIG-I or DDX58) mediated type-I interferon signal induction, interferon-gamma-inducible protein 10 (IP-10; encoded by IP10 or CXCL10) secretion, major histocompatibility complex-I expression (MHC-I) and caspase-mediated cell apoptosis. 3p-siRNA-MDR1 transfection also enhanced the anti-leukaemia efficacy of doxorubicin. These data suggest a possible synergistic role for 3p-siRNA-MDR1 in anti-leukaemia therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cytarabine With or Without SCH 900776 in Treating Adult Patients With Relapsed Acute Myeloid Leukemia

ClinicalTrials.gov

2016-07-20

Adult Acute Megakaryoblastic Leukemia; Adult Acute Monoblastic Leukemia; Adult Acute Monocytic Leukemia; Adult Acute Myeloid Leukemia With Inv(16)(p13.1q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With Maturation; Adult Acute Myeloid Leukemia With Minimal Differentiation; Adult Acute Myeloid Leukemia With t(16;16)(p13.1;q22); CBFB-MYH11; Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); RUNX1-RUNX1T1; Adult Acute Myeloid Leukemia With t(9;11)(p22;q23); MLLT3-MLL; Adult Acute Myeloid Leukemia Without Maturation; Adult Acute Myelomonocytic Leukemia; Adult Erythroleukemia; Adult Pure Erythroid Leukemia; Alkylating Agent-Related Acute Myeloid Leukemia; Recurrent Adult Acute Myeloid Leukemia

BCOR regulates myeloid cell proliferation and differentiation

PubMed Central

Cao, Qi; Gearhart, Micah D.; Gery, Sigal; Shojaee, Seyedmehdi; Yang, Henry; Sun, Haibo; Lin, De-chen; Bai, Jing-wen; Mead, Monica; Zhao, Zhiqiang; Chen, Qi; Chien, Wen-wen; Alkan, Serhan; Alpermann, Tamara; Haferlach, Torsten; Müschen, Markus; Bardwell, Vivian J.; Koeffler, H. Phillip

2016-01-01

BCOR is a component of a variant Polycomb group repressive complex 1 (PRC1). Recently, we and others reported recurrent somatic BCOR loss-of-function mutations in myelodysplastic syndrome and acute myelogenous leukaemia (AML). However, the role of BCOR in normal hematopoiesis is largely unknown. Here, we explored the function of BCOR in myeloid cells using myeloid murine models with Bcor conditional loss-of-function or overexpression alleles. Bcor mutant bone marrow cells showed significantly higher proliferation and differentiation rates with upregulated expression of Hox genes. Mutation of Bcor reduced protein levels of RING1B, an H2A ubiquitin ligase subunit of PRC1 family complexes and reduced H2AK119ub upstream of upregulated HoxA genes. Global RNA expression profiling in murine cells and AML patient samples with BCOR loss-of-function mutation suggested that loss of BCOR expression is associated with enhanced cell proliferation and myeloid differentiation. Our results strongly suggest that BCOR plays an indispensable role in hematopoiesis by inhibiting myeloid cell proliferation and differentiation and offer a mechanistic explanation for how BCOR regulates gene expression such as Hox genes. PMID:26847029

Second generation tyrosine kinase inhibitors prevent disease progression in high-risk (high CIP2A) chronic myeloid leukaemia patients.

PubMed

Lucas, C M; Harris, R J; Holcroft, A K; Scott, L J; Carmell, N; McDonald, E; Polydoros, F; Clark, R E

2015-07-01

High cancerous inhibitor of PP2A (CIP2A) protein levels at diagnosis of chronic myeloid leukaemia (CML) are predictive of disease progression in imatinib-treated patients. It is not known whether this is true in patients treated with second generation tyrosine kinase inhibitors (2G TKI) from diagnosis, and whether 2G TKIs modulate the CIP2A pathway. Here, we show that patients with high diagnostic CIP2A levels who receive a 2G TKI do not progress, unlike those treated with imatinib (P=<0.0001). 2G TKIs induce more potent suppression of CIP2A and c-Myc than imatinib. The transcription factor E2F1 is elevated in high CIP2A patients and following 1 month of in vivo treatment 2G TKIs suppress E2F1 and reduce CIP2A; these effects are not seen with imatinib. Silencing of CIP2A, c-Myc or E2F1 in K562 cells or CML CD34+ cells reactivates PP2A leading to BCR-ABL suppression. CIP2A increases proliferation and this is only reduced by 2G TKIs. Patients with high CIP2A levels should be offered 2G TKI treatment in preference to imatinib. 2G TKIs disrupt the CIP2A/c-Myc/E2F1 positive feedback loop, leading to lower disease progression risk. The data supports the view that CIP2A inhibits PP2Ac, stabilising E2F1, creating a CIP2A/c-Myc/E2F1 positive feedback loop, which imatinib cannot overcome.

Myeloid Clusters Are Associated with a Pro-Metastatic Environment and Poor Prognosis in Smoking-Related Early Stage Non-Small Cell Lung Cancer