Expression of ROR1 in Chronic Lymphocytic Leukemia Cells Enhances Cells Survival by Wnt5a Signaling.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 340-340
Author(s):  
Liguang Chen ◽  
Li Tang ◽  
Tetsu Fukuda ◽  
Thomas J. Kipps
Keyword(s):  
Tyrosine Kinase ◽  
Human Serum ◽  
Cell Survival ◽  
Cho Cells ◽  
Wnt Signaling Pathway ◽  
Leukemia Cell ◽  
Chinese Hamster ◽  
Type I ◽  
Dependent Manner

Abstract ROR1 is a type I membrane-receptor tyrosine kinase with intracellular tyrosine kinase domains and extracellular Frizzled-like cysteine-rich domains (CRDs) and kringle domains, which are common to receptors of members of the Wnt-family. We found that ROR1 might serve as an orphan receptor for Wnt5a, which can activate NF-κB via a non-canonical Wnt-signaling pathway. In prior studies we found that CLL cells expressed ROR1 and high-levels of Wnt3, Wnt5b, Wnt6, Wnt10a, Wnt14, and Wnt16, but not Wnt5a, which is found expressed on dendritic cells and other stromal cells that can support leukemia-cell survival in vitro, and presumably in vivo. As such, we examined whether cells could support the survival of CLL cells in a Wnt5a-dependent manner. For this we cultured CLL cells alone or together with Chinese Hamster Ovary (CHO) cells or CHO transduced to express Wnt5a (CHO-Wnt5a) and monitored the viability of CLL cells over time. We found that the viability of CLL cells co-cultured with CHO cells or CHO-Wnt5a cells was greater than that of CLL cells cultured alone. However the viability of CLL cells co-cultured for two days with CHO-Wnt5a cells (71% ± 18% S.D) was significantly greater than that of CLL cells co-cultured with CHO cells (45% ± 17% S.D) (N=10, P<0.01). The capacity of CHO-Wnt5a to enhance the viability of CLL cells relative to that of CHO cells could be neutralized by anti-ROR1 antisera generated in patients who received autologous CLL cells transduced to express the CD40-ligand (CD154), but not by normal human serum or pre-treatment human serum. CHO cells transduced to express ROR1, but not CHO cells transduced with a control vector, could absorb the capacity of the anti-ROR1 antisera to bind ROR1 and removed its capacity to neutralize the capacity of CHO-Wnt5a cells to provide for a protecive advantage over CHO cells for CLL cell survival in vitro. These studies provide the first evidence that the survival of CLL cells can be enhanced by cells expressing Wnt5a, let alone Wnt factors in general, and might account in part for the enhanced survival of CLL cells in tissue microenvironments containing cells that express Wnt5a. Conceivably, the anti-ROR1 antibodies induced by autologous CLL cells transduced to express CD154, or the administration of antibodies or antagonists that can inhibit Wnt5a-ROR1 signaling, could have therapeutic activity in patients with CLL.

scholarly journals YBX1 is required for maintaining myeloid leukemia cell survival by regulating BCL2 stability in an m6A-dependent manner

Blood ◽  
2021 ◽  
Author(s):  
Mengdie Feng ◽  
Xueqin Xie ◽  
Guoqiang Han ◽  
Tiantian Zhang ◽  
Yashu Li ◽  
...  
Keyword(s):  
Cell Survival ◽  
Myeloid Leukemia ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Critical Role ◽  
Leukemia Cell ◽  
Dependent Manner ◽  
Myeloid Leukemia Cell

RNA-binding proteins (RBPs) are critical regulators of transcription and translation that are often dysregulated in cancer. Although RBPs are increasingly appreciated as being important for normal hematopoiesis and for hematological malignancies as oncogenes or tumor suppressors, essential RBPs for leukemia maintenance and survival remain elusive. Here we show that YBX1 is specifically required for maintaining myeloid leukemia cell survival in an m6A-dependent manner. We found that expression of YBX1 is significantly upregulated in myeloid leukemia cells, and deletion of YBX1 dramatically induces apoptosis, promotes differentiation, coupled with reduced proliferation and impaired leukemic capacity of primary human and mouse acute myeloid leukemia (AML) cells in vitro and in vivo. Loss of YBX1 does not obviously affect normal hematopoiesis. Mechanistically, YBX1 interacts with IGF2BPs and stabilizes m6A-tagged RNA. Moreover, YBX1 deficiency dysregulates the expression of apoptosis-related genes, and promotes mRNA decay of MYC and BCL2 in an m6A-dependent manner, which contributes to the defective survival due to YBX1 deletion. Thus, our findings uncover a selective and critical role of YBX1 in maintaining myeloid leukemia survival that might provide a rationale for the therapeutic targeting of YBX1 in myeloid leukemia.

scholarly journals PRMT1-mediated FLT3 arginine methylation promotes maintenance of FLT3-ITD+ acute myeloid leukemia

Blood ◽  
2019 ◽  
Vol 134 (6) ◽  
pp. 548-560 ◽  
Author(s):  
Xin He ◽  
Yinghui Zhu ◽  
Yi-Chun Lin ◽  
Min Li ◽  
Juan Du ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Tyrosine Kinase ◽  
Myeloid Leukemia ◽  
Kinase Inhibitors ◽  
Leukemia Cell ◽  
Arginine Methylation ◽  
Type I ◽  
Dependent Manner ◽  
Arginine Methyltransferase ◽  
Acute Myeloid

Abstract The presence of FMS-like receptor tyrosine kinase-3 internal tandem duplication (FLT3-ITD) mutations in patients with acute myeloid leukemia (AML) is associated with poor clinical outcome. FLT3 tyrosine kinase inhibitors (TKIs), although effective in kinase ablation, do not eliminate primitive FLT3-ITD+ leukemia cells, which are potential sources of relapse. Thus, understanding the mechanisms underlying FLT3-ITD+ AML cell persistence is essential to devise future AML therapies. Here, we show that expression of protein arginine methyltransferase 1 (PRMT1), the primary type I arginine methyltransferase, is increased significantly in AML cells relative to normal hematopoietic cells. Genome-wide analysis, coimmunoprecipitation assay, and PRMT1-knockout mouse studies indicate that PRMT1 preferentially cooperates with FLT3-ITD, contributing to AML maintenance. Genetic or pharmacological inhibition of PRMT1 markedly blocked FLT3-ITD+ AML cell maintenance. Mechanistically, PRMT1 catalyzed FLT3-ITD protein methylation at arginine 972/973, and PRMT1 promoted leukemia cell growth in an FLT3 methylation–dependent manner. Moreover, the effects of FLT3-ITD methylation in AML cells were partially due to cross talk with FLT3-ITD phosphorylation at tyrosine 969. Importantly, FLT3 methylation persisted in FLT3-ITD+ AML cells following kinase inhibition, indicating that methylation occurs independently of kinase activity. Finally, in patient-derived xenograft and murine AML models, combined administration of AC220 with a type I PRMT inhibitor (MS023) enhanced elimination of FLT3-ITD+ AML cells relative to AC220 treatment alone. Our study demonstrates that PRMT1-mediated FLT3 methylation promotes AML maintenance and suggests that combining PRMT1 inhibition with FLT3 TKI treatment could be a promising approach to eliminate FLT3-ITD+ AML cells.

Targeting CK2 Overexpression as a Novel Therapeutic Tool in Chronic Lymphocytic Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 803-803
Author(s):  
Leila R. Martins ◽  
Paulo Lúcio ◽  
Paula Gameiro ◽  
Maria Gomes Silva ◽  
Joao T Barata
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Cell Survival ◽  
Peripheral Blood ◽  
Leukemia Cell ◽  
Lymphocytic Leukemia ◽  
Great Promise ◽  
Dependent Manner ◽  
Healthy Controls ◽  
Primary Leukemia

Abstract Abstract 803 Characterization of the molecular mechanisms that regulate viability of B cell chronic lymphocytic leukemia (CLL) cells may provide novel insights into the biology of this incurable malignancy and reveal prognostic markers and therapeutic targets. In particular, specific inhibition of signaling elements essential for leukemia cell survival offers great promise for the design of more efficient and selective therapies. The protein serine/threonine kinase CK2 is frequently upregulated in different cancers and mounting evidence implicates CK2 in tumorigenesis. In the present study, we evaluated whether CK2 may play a significant role in CLL. Peripheral blood mononuclear cells (PBMCs) from CLL patients (n=15) and healthy controls (n=7 ) were initially compared by Western blot densitometry analysis. CK2α, but not CK2β, was significantly upregulated in primary CLL patient samples (P=0.0003; Unpaired t-test), and CK2α expression clearly correlated with CK2 in vitro kinase activity (P value=0.0165). To test the functional significance of CK2 overexpression in CLL, we cultured PBMCs collected from leukemia patients (n=53) or purified CLL cells (n=7) in the presence of the CK2-specific small molecule inhibitors TBB and DRB. As determined by Annexin V-APC/7AAD staining and analysis of procaspase 3 cleavage, both TBB and DRB clearly promoted apoptosis of CLL cells (CD19+CD5+) in a time- and dose-dependent manner. Importantly, neither CK2 antagonist induced significant cell death in the normal T-cell population (CD19-CD3+) present in each PBMC patient sample. Consequently, the percentage of normal T-cells dramatically increased upon TBB/DRB treatment. Further, B-cells from healthy controls (n=7) were not affected by TBB or DRB, confirming the selectivity of the CK2 inhibitors towards leukemia cells. Notably, although co-culture with OP9 stromal cells promoted primary leukemia cell survival in vitro, it did not prevent apoptosis of CLL cells mediated by CK2 inhibition. The pro-apoptotic effect of TBB/DRB did not correlate with clinical parameters such as lymphocyte doubling time, ZAP-70 expression or IGHV mutational status. Interestingly, there was a significant association between the percentage of CLL cells in the peripheral blood and sensitivity to CK2 inhibition (e.g. 25μM TBB, P=0.0043), and treatment with 12.5μM TBB correlated with Binet stage (P=0.0043). We previously showed that CK2 phosphorylates and thereby inactivates PTEN in primary T-ALL cells leading to the hyperactivation of PI3K signaling pathway (Silva et al, JCI 2008). Here, we found that primary CLL samples displayed higher P-PTEN/PTEN ratios than healthy controls (P=0.0034), which correlated with CK2 expression (P=0.0064). Furthermore, treatment with TBB/DRB abrogated PTEN phosphorylation in 2 primary leukemia samples analyzed, suggesting that CK2 negatively regulates the activity of the tumor suppressor PTEN in CLL and raising the possibility that the pro-survival effect of CK2 may be dependent, at least in part, on the activation of PI3K pathway. Overall, our study suggests that CK2 plays an important role in the biology of CLL, and lays the groundwork for the inclusion of CK2 antagonists into future therapeutic options. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Establishment of a New Device for Electrical Stimulation of Non-Degenerative Cartilage Cells In Vitro

2021 ◽  
Vol 22 (1) ◽  
pp. 394
Author(s):  
Simone Krueger ◽  
Alexander Riess ◽  
Anika Jonitz-Heincke ◽  
Alina Weizel ◽  
Anika Seyfarth ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Electric Fields ◽  
Cartilage Tissue ◽  
Type I ◽  
Dependent Manner ◽  
New Device ◽  
Alternating Electric Fields ◽  
Cartilage Cells ◽  
Stimulation Of

In cell-based therapies for cartilage lesions, the main problem is still the formation of fibrous cartilage, caused by underlying de-differentiation processes ex vivo. Biophysical stimulation is a promising approach to optimize cell-based procedures and to adapt them more closely to physiological conditions. The occurrence of mechano-electrical transduction phenomena within cartilage tissue is physiological and based on streaming and diffusion potentials. The application of exogenous electric fields can be used to mimic endogenous fields and, thus, support the differentiation of chondrocytes in vitro. For this purpose, we have developed a new device for electrical stimulation of chondrocytes, which operates on the basis of capacitive coupling of alternating electric fields. The reusable and sterilizable stimulation device allows the simultaneous use of 12 cavities with independently applicable fields using only one main supply. The first parameter settings for the stimulation of human non-degenerative chondrocytes, seeded on collagen type I elastin-based scaffolds, were derived from numerical electric field simulations. Our first results suggest that applied alternating electric fields induce chondrogenic re-differentiation at the gene and especially at the protein level of human de-differentiated chondrocytes in a frequency-dependent manner. In future studies, further parameter optimizations will be performed to improve the differentiation capacity of human cartilage cells.

scholarly journals MicroRNA-132-3p suppresses type I IFN response through targeting IRF1 to facilitate H1N1 influenza A virus infection

2019 ◽  
Vol 39 (12) ◽  
Author(s):  
Fangyi Zhang ◽  
Xuefeng Lin ◽  
Xiaodong Yang ◽  
Guangjian Lu ◽  
Qunmei Zhang ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Peripheral Blood ◽  
Influenza A ◽  
Expression Profiles ◽  
Protein A ◽  
H1n1 Influenza ◽  
Type I ◽  
Dependent Manner ◽  
Type I Ifn

Abstract Increasing evidence has indicated that microRNAs (miRNAs) have essential roles in innate immune responses to various viral infections; however, the role of miRNAs in H1N1 influenza A virus (IAV) infection is still unclear. The present study aimed to elucidate the role and mechanism of miRNAs in IAV replication in vitro. Using a microarray assay, we analyzed the expression profiles of miRNAs in peripheral blood from IAV patients. It was found that miR-132-3p was significantly up-regulated in peripheral blood samples from IAV patients. It was also observed that IAV infection up-regulated the expression of miR-132-3p in a dose- and time-dependent manner. Subsequently, we investigated miR-132-3p function and found that up-regulation of miR-132-3p promoted IAV replication, whereas knockdown of miR-132-3p repressed replication. Meanwhile, overexpression of miR-132-3p could inhibit IAV triggered INF-α and INF-β production and IFN-stimulated gene (ISG) expression, including myxovirus protein A (MxA), 2′,5′-oligoadenylate synthetases (OAS), and double-stranded RNA-dependent protein kinase (PKR), while inhibition of miR-132-3p enhanced IAV triggered these effects. Of note, interferon regulatory factor 1 (IRF1), a well-known regulator of the type I IFN response, was identified as a direct target of miR-132-3p during HIN1 IAV infection. Furthermore, knockdown of IRF1 by si-IRF1 reversed the promoting effects of miR-132-3p inhibition on type I IFN response. Taken together, up-regulation of miR-132-3p promotes IAV replication by suppressing type I IFN response through its target gene IRF1, suggesting that miR-132-3p could represent a novel potential therapeutic target of IAV treatment.

Suppression of tumor formation in vivo by expression of the JE gene in malignant cells

1991 ◽  
Vol 11 (6) ◽  
pp. 3125-3131
Author(s):  
B J Rollins ◽  
M E Sunday
Keyword(s):  
Cho Cells ◽  
Chinese Hamster ◽  
Suppressive Effect ◽  
Tumor Formation ◽  
Host Animal ◽  
Early Growth Response ◽  
Discernible Effect ◽  
Early Growth Response Gene

The early growth response gene JE encodes a monocyte chemoattractant, MCP-1. The JE/MCP-1 protein attracts and stimulates human monocytes and induces monocyte-mediated inhibition of tumor cell growth in vitro. Expression of human or murine JE/MCP-1 in Chinese hamster ovary (CHO) cells completely suppressed their ability to form tumors in nude mice. Coinjection of JE/MCP-1-expressing cells with nonexpressing CHO cells or with HeLa cells also prevented tumor formation. Since JE/MCP-1 expression had no discernible effect on the tranformed phenotype of these cells in vitro, the suppressive effect depends on host animal factors. These factors are likely to be components of the inflammatory response, because JE/MCP-1-expressing cells elicited a predominantly monocytic infiltrate at the site of injection. Our results suggest that JE/MCP-1 protein may be useful in cancer therapy.

scholarly journals cDNA cloning and expression of a human platelet-derived growth factor (PDGF) receptor specific for B-chain-containing PDGF molecules.

1988 ◽  
Vol 8 (8) ◽  
pp. 3476-3486 ◽  
Author(s):  
L Claesson-Welsh ◽  
A Eriksson ◽  
A Morén ◽  
L Severinsson ◽  
B Ek ◽  
...  
Keyword(s):  
Amino Acid ◽  
Growth Factor ◽  
Cdna Cloning ◽  
Cho Cells ◽  
Chinese Hamster ◽  
Cloning And Expression ◽  
Platelet Derived Growth Factor ◽  
Amino Acid Sequence Similarity ◽  
Pdgf Receptor

The structure of the human receptor for platelet-derived growth factor (PDGF) has been deduced through cDNA cloning. A 5.45-kilobase-pair cDNA clone predicts a 1,106-amino-acid polypeptide, including the cleavable signal sequence. The overall amino acid sequence similarity with the murine PDGF receptor is 85%. After transcription of the cDNA and translation in vitro, a PDGF receptor antiserum was used to immunoprecipitate a product of predicted size, which also could be phosphorylated in vitro. Stable introduction of the cDNA into Chinese hamster ovary (CHO) cells led to the expression of a 190-kilodalton component, which was immunoprecipitated by the PDGF receptor antiserum; this most probably represents the mature PDGF receptor. Binding assays with different 125I-labeled dimeric forms of PDGF A and B chains showed that the PDGF receptor expressed in CHO cells bound PDGF-BB and, to a lesser extent, PDGF-AB, but not PDGF-AA.

Chemical Characterization and Anti-inflammatory Activity of Polysaccharides from Zizyphus jujube cv. Muzao

2017 ◽  
Vol 13 (7) ◽  
Author(s):  
Xiaolong Ji ◽  
Qiang Peng ◽  
Huanyu Li ◽  
Fang Liu ◽  
Min Wang
Keyword(s):  
Chemical Characterization ◽  
Type I ◽  
Dependent Manner ◽  
Necrosis Factor Alpha ◽  
Assisted Extraction ◽  
Ultrasonic Assisted ◽  
Potential Applications ◽  
Anti Inflammatory ◽  
Zizyphus Jujube

AbstractPolysaccharides fromZizyphus jujube cv. Muzao(ZMP) were extracted by ultrasonic-assisted extraction with acidic buffer. The chemical composition and antioxidant and anti-inflammatory activities of ZMP were evaluated. The results revealed that ZMP had a molecular weight of 89.90 kDa and consisted of arabinose, galactose, glucose, rhamnose, and mannose, with molar percentages of 4.52 %, 2.64 %, 1.04 %, 0.49 %, and 0.41 %, respectively. Based on Fourier-transform infrared spectroscopy, ZMP belonged to the type I rhamnogalacturonans family. In vitro antioxidants assays revealed that ZMP had remarkable antioxidant activity in a dose-dependent manner. Proinflammatory cytokines, such as interleukin-6 and tumor necrosis factor alpha, were suppressed by ZMP in lipopolysaccharide-treated RAW264.7 cells. Overall, the results revealed that ZMP has potential applications as a natural anti-inflammatory agent.

scholarly journals SAMHD1 Phosphorylation Coordinates the Anti-HIV-1 Response by Diverse Interferons and Tyrosine Kinase Inhibition

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Matthew A. Szaniawski ◽  
Adam M. Spivak ◽  
James E. Cox ◽  
Jonathan L. Catrow ◽  
Timothy Hanley ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitors ◽  
Kinase Inhibitors ◽  
Restriction Factor ◽  
Type I ◽  
Dependent Manner ◽  
Type Ii ◽  
Type Iii ◽  
Type Iii Ifn ◽  
Hiv 1

ABSTRACTMacrophages are susceptible to human immunodeficiency virus type 1 (HIV-1) infection despite abundant expression of antiviral proteins. Perhaps the most important antiviral protein is the restriction factor sterile alpha motif domain and histidine/aspartic acid domain-containing protein 1 (SAMHD1). We investigated the role of SAMHD1 and its phospho-dependent regulation in the context of HIV-1 infection in primary human monocyte-derived macrophages and the ability of various interferons (IFNs) and pharmacologic agents to modulate SAMHD1. Here we show that stimulation by type I, type II, and to a lesser degree, type III interferons share activation of SAMHD1 via dephosphorylation at threonine-592 as a consequence of signaling. Cyclin-dependent kinase 1 (CDK1), a known effector kinase for SAMHD1, was downregulated at the protein level by all IFN types tested. Pharmacologic inhibition or small interfering RNA (siRNA)-mediated knockdown of CDK1 phenocopied the effects of IFN on SAMHD1. A panel of FDA-approved tyrosine kinase inhibitors potently induced activation of SAMHD1 and subsequent HIV-1 inhibition. The viral restriction imposed via IFNs or dasatinib could be overcome through depletion of SAMHD1, indicating that their effects are exerted primarily through this pathway. Our results demonstrate that SAMHD1 activation, but not transcriptional upregulation or protein induction, is the predominant mechanism of HIV-1 restriction induced by type I, type II, and type III IFN signaling in macrophages. Furthermore, SAMHD1 activation presents a pharmacologically actionable target through which HIV-1 infection can be subverted.IMPORTANCEOur experimental results demonstrate that SAMHD1 dephosphorylation at threonine-592 represents a central mechanism of HIV-1 restriction that is common to the three known families of IFNs. While IFN types I and II were potent inhibitors of HIV-1, type III IFN showed modest to undetectable activity. Regulation of SAMHD1 by IFNs involved changes in phosphorylation status but not in protein levels. Phosphorylation of SAMHD1 in macrophages occurred at least in part via CDK1. Tyrosine kinase inhibitors similarly induced SAMHD1 dephosphorylation, which protects macrophages from HIV-1 in a SAMHD1-dependent manner. SAMHD1 is a critical restriction factor regulating HIV-1 infection of macrophages.

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