Inhibition of cell proliferation by lenalidomide is associated with stimulation of Egr1 transcriptional activity in a chromosome 5 deleted Burkitt’s lymphoma and multiple myeloma cell line

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 8110-8110 ◽  
Author(s):  
A. K. Gandhi ◽  
J. Kang ◽  
D. Verhelle ◽  
D. I. Stirling ◽  
P. H. Schafer
Keyword(s):  
Cell Proliferation ◽  
Tumor Suppressor ◽  
Cell Line ◽  
Transcriptional Activity ◽  
Nuclear Transport ◽  
Burkitt’S Lymphoma ◽  
Burkitt's Lymphoma ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Chromosome 5

8110 Background: The mechanism by which lenalidomide exerts its anti-proliferative effects in deletion 5q MDS clones or MM cells is not yet fully elucidated. Early growth response (Egr1) gene is a tumor suppressor gene located on chromosome 5q31.1 that encodes a transcription factor involved in the regulation of cell proliferation and apoptosis. We hypothesized that lenalidomide may act by enhancing the expression or activity of Egr1 in sensitive hematopoietic tumor cells, especially those with only a single copy of the Egr1 gene. Methods: Transcriptional activity was measured using luciferase reporter plasmids. Gene knockdown and expression studies used siRNA technology and qRT-PCR, respectively. Cell proliferation was measured by 3H-thymidine incorporation. Results: Lenalidomide stimulated the transcriptional activity of Egr1 in the lenalidomide-sensitive chromosome 5 deleted Burkitt's lymphoma Namalwa CSN.70 and in the MM cell line LP-1. Egr1 siRNA Namalwa cells proliferated more than mock controls, indicating that Egr1 functions as a tumor suppressor in Namalwa cells. Lenalidomide had no effect on expression of Egr1, but augmented Egr1 nuclear transport in a dose-dependent manner. Lenalidomide did not affect expression of the Egr1 downstream effector genes ATF3, fibronectin, p53, PTEN, and TGF-β1, while p21 levels increased. However, lenalidomide-induced p21 expression was not affected in Egr1 siRNA Namalwa cells. Interestingly, lenalidomide’s anti-proliferative potency was greater in Egr1 siRNA Namalwa but not in Egr1 siRNA LP-1 cells. Conclusions: Lenalidomide induces nuclear transport and transcriptional activation of the tumor suppressor Egr1, which may contribute to lenalidomide’s anti-proliferative activity in a non-p21 dependent manner. This activity may be related to the levels of Egr1 expression, explaining why del 5q31 myelodysplastic clones are especially sensitive to the cytotoxic effects of lenalidomide. No significant financial relationships to disclose.

Lenalidomide Displays Anti-Proliferative Activity and Combination Effects with Chemotherapeutic Agents Against a Burkitt’s Lymphoma Cell Line.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4516-4516
Author(s):  
Anita K. Gandhi ◽  
Jian Kang ◽  
Ling-Hua Zhang ◽  
Blake Bartlett ◽  
Peter H. Schafer ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Line ◽  
Kinase Inhibitor ◽  
Single Agent ◽  
Tumor Cell Line ◽  
Metabolic Activation ◽  
Burkitt’S Lymphoma ◽  
Chemotherapeutic Agents ◽  
Burkitt's Lymphoma ◽  
Cytochrome P450 Enzymes

Abstract Background: Lenalidomide (Revlimid®) is approved for the treatment of del 5q myelodysplastic syndrome (MDS) and in combination with dexamethasone for previously treated multiple myeloma. It is currently being evaluated as treatment for other hematology and oncology conditions, including NHL as a single agent and in combination with other therapeutics. Aims: The present study evaluates the effect of lenalidomide on the proliferation of the Burkitt’s Lymphoma tumor cell line Namalwa CSN.70, as a single agent and in combination with various chemotherapeutic agents: dexamethasone, doxorubicin, vincristine, methotrexate, cytarabine, ifosfamide, cyclophosphamide, carmustine, prednisone, etoposide, rituximab, bortezomib, rapamycin, and the mixed kinase inhibitor UCN-01. Methods: Namalwa CSN.70 cells were incubated in 96-well cell culture plates with compounds for 72 hours and cell proliferation was assayed by 3H-thymidine incorporation. IC50s were calculated by nonlinear regression analyses with GraphPad Prism. Results: Namalwa cell proliferation was inhibited by lenalidomide and the chemotherapeutic agents dexamethasone, doxorubicin, vincristine, methotrexate, cytarabine, carmustine, prednisone and etoposide. Cyclophosphamide and ifosfamide had no effect, since these agents require metabolic activation by cytochrome P450 enzymes. Lenalidomide combined with dexamethasone displayed synergistic anti-proliferative effects. Lenalidomide combined with prednisone displayed partially additive anti-proliferative effects at prednisone concentrations within the range of 0.5 and 50 mM, although this was non-additive at lower concentrations of both drugs. Lenalidomide combined with etoposide displayed partially additive anti-proliferative effects at etoposide concentrations within the concentration range of 0.05 and 0.5 mM, although at lower concentrations the response became non-additive and comparable to the effect of lenalidomide alone. In contrast, lenalidomide combined with carmustine displayed antagonistic effects at low concentrations, although partially additive anti-proliferative effects were observed at higher concentrations. Lenalidomide combined with methotrexate was also antagonistic. Lenalidomide in combination with cytarabine, doxorubicin, or vincristine generated anti-proliferative responses that were equivalent to the inhibition produced by these respective chemotherapeutic agents alone. Finally, rituximab was unable to add to the anti-proliferative effect of lenalidomide, consistent with the rituximab mechanism of action being primarily antibody-dependent cell-mediated cytotoxicity (ADCC), rather than direct apoptotic signaling since there is data showing the benefit of this combination in a mouse model of disseminated NHL (Hernandez-Ilizaliturri et al. 2005 Clin Cancer Res. 11:5984). Conclusions: These results support the potential for a synergistic effect of lenalidomide in combination with dexamethasone in NHL. Furthermore, partially additive effects of lenalidomide with prednisone and etoposide suggest these may be useful combinations. Results with bortezomib, rapamycin and UCN-01 will also be discussed.

The Anti-Atherogenic Properties of Sesamin are Mediated via Improved Macrophage Cholesterol Efflux Through PPARγ1-LXRα and MAPK Signaling

2014 ◽  
Vol 84 (1-2) ◽  
pp. 79-91 ◽  
Author(s):  
Amin F. Majdalawieh ◽  
Hyo-Sung Ro
Keyword(s):  
Cholesterol Efflux ◽  
Transcriptional Activity ◽  
Molecular Mechanisms ◽  
Foam Cell ◽  
Mapk Signaling ◽  
Luciferase Reporter ◽  
Foam Cell Formation ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Macrophage Cholesterol Efflux

Background: Foam cell formation resulting from disrupted macrophage cholesterol efflux, which is triggered by PPARγ1 and LXRα, is a hallmark of atherosclerosis. Sesamin and sesame oil exert anti-atherogenic effects in vivo. However, the exact molecular mechanisms underlying such effects are not fully understood. Aim: This study examines the potential effects of sesamin (0, 25, 50, 75, 100 μM) on PPARγ1 and LXRα expression and transcriptional activity as well as macrophage cholesterol efflux. Methods: PPARγ1 and LXRα expression and transcriptional activity are assessed by luciferase reporter assays. Macrophage cholesterol efflux is evaluated by ApoAI-specific cholesterol efflux assays. Results: The 50 μM, 75 μM, and 100 μM concentrations of sesamin up-regulated the expression of PPARγ1 (p< 0.001, p < 0.001, p < 0.001, respectively) and LXRα (p = 0.002, p < 0.001, p < 0.001, respectively) in a concentration-dependent manner. Moreover, 75 μM and 100 μM concentrations of sesamin led to 5.2-fold (p < 0.001) and 6.0-fold (p<0.001) increases in PPAR transcriptional activity and 3.9-fold (p< 0.001) and 4.2-fold (p < 0.001) increases in LXR transcriptional activity, respectively, in a concentration- and time-dependent manner via MAPK signaling. Consistently, 50 μM, 75 μM, and 100 μM concentrations of sesamin improved macrophage cholesterol efflux by 2.7-fold (p < 0.001), 4.2-fold (p < 0.001), and 4.2-fold (p < 0.001), respectively, via MAPK signaling. Conclusion: Our findings shed light on the molecular mechanism(s) underlying sesamin’s anti-atherogenic effects, which seem to be due, at least in part, to its ability to up-regulate PPARγ1 and LXRα expression and transcriptional activity, improving macrophage cholesterol efflux. We anticipate that sesamin may be used as a therapeutic agent for treating atherosclerosis.

Norepinephrine induces calcium spikes and proinflammatory actions in human hepatic stellate cells

2006 ◽  
Vol 291 (5) ◽  
pp. G877-G884 ◽  
Author(s):  
Pau Sancho-Bru ◽  
Ramón Bataller ◽  
Jordi Colmenero ◽  
Xavier Gasull ◽  
Montserrat Moreno ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Portal Hypertension ◽  
Liver Fibrosis ◽  
Hepatic Stellate Cells ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Stellate Cells ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Cell Contraction

Catecholamines participate in the pathogenesis of portal hypertension and liver fibrosis through α1-adrenoceptors. However, the underlying cellular and molecular mechanisms are largely unknown. Here, we investigated the effects of norepinephrine (NE) on human hepatic stellate cells (HSC), which exert vasoactive, inflammatory, and fibrogenic actions in the injured liver. Adrenoceptor expression was assessed in human HSC by RT-PCR and immunocytochemistry. Intracellular Ca2+ concentration ([Ca2+]i) was studied in fura-2-loaded cells. Cell contraction was studied by assessing wrinkle formation and myosin light chain II (MLC II) phosphorylation. Cell proliferation and collagen-α1(I) expression were assessed by [3H]thymidine incorporation and quantitative PCR, respectively. NF-κB activation was assessed by luciferase reporter gene and p65 nuclear translocation. Chemokine secretion was assessed by ELISA. Normal human livers expressed α1A-adrenoceptors, which were markedly upregulated in livers with advanced fibrosis. Activated human HSC expressed α1A-adrenoceptors. NE induced multiple rapid [Ca2+]i oscillations (Ca2+ spikes). Prazosin (α1-blocker) completely prevented NE-induced Ca2+ spikes, whereas propranolol (nonspecific β-blocker) partially attenuated this effect. NE caused phosphorylation of MLC II and cell contraction. In contrast, NE did not affect cell proliferation or collagen-α1(I) expression. Importantly, NE stimulated the secretion of inflammatory chemokines (RANTES and interleukin-8) in a dose-dependent manner. Prazosin blocked NE-induced chemokine secretion. NE stimulated NF-κB activation. BAY 11-7082, a specific NF-κB inhibitor, blocked NE-induced chemokine secretion. We conclude that NE stimulates NF-κB and induces cell contraction and proinflammatory effects in human HSC. Catecholamines may participate in the pathogenesis of portal hypertension and liver fibrosis by targeting HSC.

Epinephrine Stimulates Cell Proliferation and Induces Chemoresistance in Myeloma Cells through the β-Adrenoreceptor in vitro

2017 ◽  
Vol 138 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Yang Liu ◽  
Xiaochen Yu ◽  
Junling Zhuang
Keyword(s):  
Cell Proliferation ◽  
Cell Growth ◽  
Cell Line ◽  
Receptor Subtype ◽  
Dependent Manner ◽  
Myeloma Cells ◽  
U266 Cell ◽  
Β Receptor ◽  
U266 Cell Line

Objectives: To explore the effect of the β-adrenoreceptor signaling pathway on myeloma cells. Methods: The myeloma U266 cell line was treated with epinephrine and propranolol. Cell proliferation was analyzed by MTS assay. Apoptosis was detected by flow cytometry. The β-receptor subtype and the key enzyme of epinephrine were identified by reverse transcription polymerase chain reaction (RT-PCR). Results: Epinephrine (5-50 μM) promoted U266 cell growth in a dose-dependent manner and neutralized the inhibition effect of bortezomib (25 and 50 ng/mL) in vitro. Cell proliferation was inhibited by a β-receptor antagonist, propranolol, at a concentration of 50-200 μM. The proportions of early and late apoptotic cells were enhanced after treatment with propranolol. The expression of caspase 3/7, 8, and 9 was elevated in propranolol-treated myeloma cells. Both β1- and β2-adrenoceptor mRNAs were expressed in the U266 cell line. Key enzymes dopamine hydroxylase and tyrosinehydroxylase were identified in myeloma cells. Conclusions: Our results reveal that epinephrine stimulates myeloma cell growth in vitro while the β-blocker propranolol has an antiproliferative effect, indicating that stress hormones may trigger the progression of myeloma.

scholarly journals Endothelial NO Synthase-Dependent S-Nitrosylation of β-Catenin Prevents Its Association with TCF4 and Inhibits Proliferation of Endothelial Cells Stimulated by Wnt3a

2017 ◽  
Vol 37 (12) ◽  
Author(s):  
Ying Zhang ◽  
Rony Chidiac ◽  
Chantal Delisle ◽  
Jean-Philippe Gratton
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Transcriptional Activity ◽  
No Synthase ◽  
Endothelial Cell Proliferation ◽  
Dependent Manner ◽  
Endothelial No Synthase ◽  
Binding Interface ◽  
Critical Residue

ABSTRACT Nitric oxide (NO) produced by endothelial NO synthase (eNOS) modulates many functions in endothelial cells. S-nitrosylation (SNO) of cysteine residues on β-catenin by eNOS-derived NO has been shown to influence intercellular contacts between endothelial cells. However, the implication of SNO in the regulation of β-catenin transcriptional activity is ill defined. Here, we report that NO inhibits the transcriptional activity of β-catenin and endothelial cell proliferation induced by activation of Wnt/β-catenin signaling. Interestingly, induction by Wnt3a of β-catenin target genes, such as the axin2 gene, is repressed in an eNOS-dependent manner by vascular endothelial growth factor (VEGF). We identified Cys466 of β-catenin as a target for SNO by eNOS-derived NO and as the critical residue for the repressive effects of NO on β-catenin transcriptional activity. Furthermore, we observed that Cys466 of β-catenin, located at the binding interface of the β-catenin–TCF4 transcriptional complex, is essential for disruption of this complex by NO. Importantly, Cys466 of β-catenin is necessary for the inhibitory effects of NO on Wnt3a-stimulated proliferation of endothelial cells. Thus, our data define the mechanism responsible for the repressive effects of NO on the transcriptional activity of β-catenin and link eNOS-derived NO to the modulation by VEGF of Wnt/β-catenin-induced endothelial cell proliferation.

scholarly journals Oncogenic Role of Epstein-Barr Virus-Encoded RNAs in Burkitt’s Lymphoma Cell Line Akata

1999 ◽  
Vol 73 (12) ◽  
pp. 9827-9831 ◽  
Author(s):  
Jun Komano ◽  
Seiji Maruo ◽  
Koichi Kurozumi ◽  
Takanori Oda ◽  
Kenzo Takada
Keyword(s):  
Cell Line ◽  
Small Rnas ◽  
Epstein Barr Virus ◽  
Burkitt’S Lymphoma ◽  
Soft Agar ◽  
Burkitt's Lymphoma ◽  
Malignant Phenotype ◽  
Barr Virus ◽  
Epstein Barr

ABSTRACT Our previous reports indicated that Epstein-Barr virus (EBV) contributes to the malignant phenotype and resistance to apoptosis in Burkitt’s lymphoma (BL) cell line Akata (N. Shimizu, A. Tanabe-Tochikura, Y. Kuroiwa, and K. Takada, J. Virol. 68:6069–6073, 1994; J. Komano, M. Sugiura, and K. Takada, J. Virol. 72:9150–9156, 1998). Here we report that the EBV-encoded small RNAs (EBERs) are responsible for these phenotypes. Transfection of the EBER genes into EBV-negative Akata clones restored the capacity for growth in soft agar, tumorigenicity in SCID mice, resistance to apoptotic inducers, and upregulated expression of bcl-2 oncoprotein that were originally retained in parental EBV-positive Akata cells and lost in EBV-negative subclones. This is the first report which provides evidence that virus-encoded RNAs (EBERs) have oncogenic functions in BL cells.

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