Novel Adapter Proteins that Link the Human GM-CSF Receptor to the Phosphatidylino-sitol 3-Kinase and Shc/Grb2/ras Signaling Pathways

1996 ◽  
pp. 67-75
Author(s):  
M. Jücker ◽  
R. A. Feldman
Keyword(s):  
Signaling Pathways ◽  
Ras Signaling ◽  
Adapter Proteins ◽  
Gm Csf

scholarly journals Statins induce apoptosis through inhibition of Ras signaling pathways and enhancement of Bim and p27 expression in human hematopoietic tumor cells

Tumor Biology ◽  
2017 ◽  
Vol 39 (10) ◽  
pp. 101042831773494 ◽  
Author(s):  
Daichiro Fujiwara ◽  
Masanobu Tsubaki ◽  
Tomoya Takeda ◽  
Yoshika Tomonari ◽  
Yu-ichi Koumoto ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Tumor Cells ◽  
Ras Signaling

scholarly journals Signaling through mitogen-activated protein kinase and Rac/Rho does not duplicate the effects of activated Ras on skeletal myogenesis.

1997 ◽  
Vol 17 (7) ◽  
pp. 3547-3555 ◽  
Author(s):  
M B Ramocki ◽  
S E Johnson ◽  
M A White ◽  
C L Ashendel ◽  
S F Konieczny ◽  
...  
Keyword(s):  
Map Kinase ◽  
Signaling Pathways ◽  
Transcriptional Activation ◽  
Intracellular Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Ras Signaling ◽  
Negative Effects ◽  
Intracellular Signaling Pathway ◽  
Helix Loop Helix ◽  
Mitogen Activated Protein

The ability of basic helix-loop-helix muscle regulatory factors (MRFs), such as MyoD, to convert nonmuscle cells to a myogenic lineage is regulated by numerous growth factor and oncoprotein signaling pathways. Previous studies have shown that H-Ras 12V inhibits differentiation to a skeletal muscle lineage by disrupting MRF function via a mechanism that is independent of the dimerization, DNA binding, and inherent transcriptional activation properties of the proteins. To investigate the intracellular signaling pathway(s) that mediates the inhibition of MRF-induced myogenesis by oncogenic Ras, we tested two transformation-defective H-Ras 12V effector domain variants for their ability to alter terminal differentiation. H-Ras 12V,35S retains the ability to activate the Raf/MEK/mitogen-activated protein (MAP) kinase cascade, whereas H-Ras 12V,40C is unable to interact directly with Raf-1 yet still influences other signaling intermediates, including Rac and Rho. Expression of each H-Ras 12V variant in C3H10T1/2 cells abrogates MyoD-induced activation of the complete myogenic program, suggesting that MAP kinase-dependent and -independent Ras signaling pathways individually block myogenesis in this model system. However, additional studies with constitutively activated Rac1 and RhoA proteins revealed no negative effects on MyoD-induced myogenesis. Similarly, treatment of Ras-inhibited myoblasts with the MEK1 inhibitor PD98059 revealed that elevated MAP kinase activity is not a significant contributor to the H-Ras 12V effect. These data suggest that an additional Ras pathway, distinct from the well-characterized MAP kinase and Rac/Rho pathways known to be important for the transforming function of activated Ras, is primarily responsible for the inhibition of myogenesis by H-Ras 12V.

scholarly journals Ras and Wnt Interaction Contribute in Prostate Cancer Bone Metastasis

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2380 ◽  
Author(s):  
Shian-Ren Lin ◽  
Ntlotlang Mokgautsi ◽  
Yen-Nien Liu
Keyword(s):  
Prostate Cancer ◽  
Bone Marrow ◽  
Bone Metastasis ◽  
Signaling Pathways ◽  
Late Stage ◽  
Ras Signaling ◽  
Cancer Death ◽  
Metastatic Site ◽  
Cancer Types ◽  
Cytological Changes

Prostate cancer (PCa) is one of the most prevalent and malignant cancer types in men, which causes more than three-hundred thousand cancer death each year. At late stage of PCa progression, bone marrow is the most often metastatic site that constitutes almost 70% of metastatic cases of the PCa population. However, the characteristic for the osteo-philic property of PCa is still puzzling. Recent studies reported that the Wnt and Ras signaling pathways are pivotal in bone metastasis and that take parts in different cytological changes, but their crosstalk is not well studied. In this review, we focused on interactions between the Wnt and Ras signaling pathways during each stage of bone metastasis and present the fate of those interactions. This review contributes insights that can guide other researchers by unveiling more details with regard to bone metastasis and might also help in finding potential therapeutic regimens for preventing PCa bone metastasis.

RAS and Leukemia: From Basic Mechanisms to Gene-Directed Therapy

1999 ◽  
Vol 17 (3) ◽  
pp. 1071-1071 ◽  
Author(s):  
Darrin M. Beaupre ◽  
Razelle Kurzrock
Keyword(s):  
Signaling Pathways ◽  
Posttranslational Modification ◽  
Antitumor Agents ◽  
Biologically Active ◽  
Ras Signaling ◽  
Farnesyl Transferase ◽  
Therapeutic Implications ◽  
Farnesyl Transferase Inhibitors

PURPOSE AND DESIGN: The purpose of this review is to provide an overview of the literature linking Ras signaling pathways and leukemia and to discuss the biologic and potential therapeutic implications of these observations. A search of MEDLINE from 1966 to October 1998 was performed. RESULTS: A wealth of data has been published on the role of Ras pathways in cancer. To be biologically active, Ras must move from the cytoplasm to the plasma membrane. Importantly, a posttranslational modification—addition of a farnesyl group to the Ras C-terminal cysteine—is a requisite for membrane localization of Ras. Farnesylation of Ras is catalyzed by an enzyme that is designated farnesyltranferase. Recently, several compounds have been developed that can inhibit farnesylation. Preclinical studies indicate that these molecules can suppress transformation and tumor growth in vitro and in animal models, with little toxicity to normal cells. CONCLUSION: An increasing body of data suggests that disruption of Ras signaling pathways, either directly through mutations or indirectly through other genetic aberrations, is important in the pathogenesis of a wide variety of cancers. Molecules such as farnesyl transferase inhibitors that interfere with the function of Ras may be exploitable in leukemia (as well as in solid tumors) as novel antitumor agents.

scholarly journals Chinese Herbal Formula, Huayu Tongbi Fang, Attenuates Inflammatory Proliferation of Rat Synoviocytes Induced by IL-1β by Regulating Proliferation and Differentiation of T Lymphocytes

2020 ◽  
Vol 2020 ◽  
pp. 1-18 ◽  
Author(s):  
Hening Chen ◽  
Changzhi Wang ◽  
Jinyu Li ◽  
Meiyier Huandike ◽  
Juan Liu ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Protein Expression ◽  
Signaling Pathways ◽  
Interleukin 1 ◽  
Cell Subset ◽  
Enzyme Linked Immunosorbent Assay ◽  
Herbal Formula ◽  
Gm Csf ◽  
Freeze Dried ◽  
Proliferation And Differentiation

The inflammatory proliferation of fibroblast-like synoviocytes (FLSs) and functional imbalances in T lymphocytes play critical roles in the pathogenesis of rheumatoid arthritis (RA). The clinical efficacy of Huayu Tongbi Fang (HYTB, a traditional herbal formula) in RA treatment has been validated. In this study, we aimed to explore the regulatory mechanisms of HYTB on the proliferation and differentiation of T lymphocytes, and the inhibitory effect of HYTB on inflammatory proliferation of FLSs. The RCS-364 (Rat FLSs) cells were cocultured with rat splenic lymphocytes that were induced by interleukin-1β in Transwell chambers. After freeze-dried HYTB powder treatment, the percentage of T-cell subset and apoptosis rates of FLSs were measured using flow cytometry. Furthermore, protein expression of key molecules of NF-κB and JAK/STAT signaling pathways was quantified using Western blot. The granulocyte-macrophage colony-stimulating factor (GM-CSF) was measured using enzyme-linked immunosorbent assay. The results showed that HYTB could inhibit the inflammatory proliferation of FLSs through inducing cell apoptosis. Additionally, HYTB treatment could intervene in the proliferation and differentiation of T lymphocytes and regulate protein expression of key molecules in NF-κB and JAK/STAT cell signaling pathways. Moreover, it could inhibit FLS activation by suppressing GM-CSF production by T cells and FLSs. Therefore, the HYTB formula should be used as a traditional medicine against RA in modern complementary and alternative therapies.

Correlation between MDSC and Immune Tolerance in Transplantation: Cytokines, Pathways and Cell-cell Interaction

2019 ◽  
Vol 19 (2) ◽  
pp. 81-92 ◽  
Author(s):  
Tianying Yang ◽  
Jiawei Li ◽  
Ruimin Li ◽  
Chunchen Yang ◽  
Weitao Zhang ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Graft Survival ◽  
Immune Tolerance ◽  
Immune Cells ◽  
Cell Interaction ◽  
Erk Signaling ◽  
Gm Csf ◽  
Cytokines And Chemokines ◽  
Direct Suppression ◽  
Cell Cell

MDSCs play an important role in the induction of immune tolerance. Cytokines and chemokines (GM-CSF, IL-6) contributed to the expansion, accumulation of MDSCs, and MDSCs function through iNOS, arginase and PD-L1. MDSCs are recruited and regulated through JAK/STAT, mTOR and Raf/MEK/ERK signaling pathways. MDSCs’ immunosuppressive functions were realized through Tregs-mediated pathways and their direct suppression of immune cells. All of the above contribute to the MDSC-related immune tolerance in transplantation. MDSCs have huge potential in prolonging graft survival and reducing rejection through different ways and many other factors worthy to be further investigated are also introduced.

Rapamycin -- a Potential Mechanistically Targeted Therapeutic for Juvenile Myelomonocytic Leukemia.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2378-2378
Author(s):  
Y. Lucy Liu ◽  
Robert P. Castleberry ◽  
Peter Dean Emanuel
Keyword(s):  
Philadelphia Chromosome ◽  
Disease Free Survival ◽  
Juvenile Myelomonocytic Leukemia ◽  
Ras Signaling ◽  
Sensitivity Testing ◽  
Blood Concentrations ◽  
Patient Sample ◽  
Gm Csf ◽  
Myelomonocytic Leukemia

Abstract Juvenile myelomonocytic leukemia (JMML) is a mixed myelodysplastic /myeloproliferative disorder (MDS/MPD) of infancy and early childhood. It is characterized by monocytosis, leukocytosis, elevated fetal hemoglobin, hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF), a low percentage of myeloblasts in the bone marrow, and absence of the Philadelphia chromosome or the BCR/ABL fusion gene. The pathogenesis of JMML has been clearly and definitively linked to dysregulated signal transduction through the RAS signaling pathway. A series of studies conducted over the last decade have shown that mutations or other abnormalities in RAS, NF1, and PTPN11, are potentially responsible for the pathogenesis of JMML in up to 75% of cases. Treatment has been very difficult. There is no effective therapy for JMML. Only allogeneic stem cell transplantation (SCT) can extend survival. However, the relapse rate from allogeneic SCT is inordinately high in JMML (28–55%), with 5-year disease-free survival rates of 25-40%. Rapamycin is a macrolide antibiotic with established clinical applications in organ transplantation. Recent studies have proved that the Mammalian Target of Rapamycin (mTOR) plays an important role in cytokine receptor signaling and induction of apoptosis. Numerous studies have suggested that mTOR functions as a nutritional checkpoint and is connected to energy sensing through AMP-dependent kinase (AMPK) which senses the AMP: ATP ratio in cells. Its function is regulated by the RAS/PI3-kinase pathway. In searching for novel mechanistically-targeted reagents to treat JMML, we conducted an in vitro pilot study with JMML cells. The CFU-GM formation assay was used to test the therapeutic sensitivity of rapamycin to JMML cells. Mononuclear cells (MNCs) from peripheral blood of 9 JMML patients were collected and plated on 0.3% agar medium with rapamycin at a concentration of 1-8nM(0.91-7.28μg/L) and carrier (DMSO). Greater than 50% inhibition of spontaneous CFU-GM growth was observed in all cultures in a dose-dependent fashion, with the exception of one patient sample which had colonies resistant to rapamycin. The effective concentrations in our cultures are equivalent to the safe and tolerable whole blood concentrations achieved in organ transplant patients in clinical settings (5-30μg/L). Our data suggests that rapamycin may be considered as a potentially safe and effective reagent to treat JMML, but that in vitro sensitivity testing might be recommended since one patient sample demonstrated complete resistance to rapamycin in vitro. Further studies are ongoing to explore the mechanism of rapamycin in inhibiting hypersensitivity of JMML cells to GM-CSF.

CREB Deficiency: A Potential Critical Factor for Selective GM-CSF Hypersensitivity in Juvenile Myelomonocytic Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2604-2604
Author(s):  
Y. Lucy Liu ◽  
Priyangi A Malaviarachchi ◽  
Shelly Y. Lensing ◽  
Robert P. Castleberry ◽  
Peter Dean Emanuel
Keyword(s):  
Conflicts Of Interest ◽  
Myeloproliferative Neoplasm ◽  
Juvenile Myelomonocytic Leukemia ◽  
Ras Signaling ◽  
Camp Response Element ◽  
Response Element ◽  
Creb Protein ◽  
Gm Csf ◽  
Myelomonocytic Leukemia ◽  
Normal Controls

Abstract Abstract 2604 Poster Board II-580 Juvenile myelomonocytic leukemia (JMML) is a mixed myelodysplastic /myeloproliferative neoplasm (MDS/MPN) of infancy and early childhood. The pathogenesis of JMML has been linked to dysregulated signal transduction through the NF1/RAS signaling pathway and PTPN11. This dysregulation results in JMML cells demonstrating selective hypersensitivity to GM-CSF in in vitro dose-response assays. Since JMML hematopoietic progenitor cells are selectively hypersensitive to (rather than independent of) GM-CSF, it is rational to hypothesize that the function of the GM-CSF receptor in JMML patients is not constitutively over-active unless stimulated by the cytokine. We previously reported that PTEN is deficient in JMML patients. PTEN expression is up-regulated by Egr-1, which is one of the targets of the cAMP-response-element-binding protein (CREB). CREB, as a transcriptional factor, is expressed ubiquitously and bound to the cAMP-response-element (CRE) of the Egr-1 promoter. After phosphorylation at serine 133, CREB selectively activates the transcription of Egr-1 in response to GM-CSF stimulation in hematopoietic cells. We evaluated the CREB protein level in peripheral blood or bone marrow samples collected from 26 JMML patients. Mononuclear cells (MNCs) were isolated and lysed in lysis buffer at a density of 107/100μl. Protein levels of CREB were evaluated by ELISA and Western-blot. We found that 22/26 (85%) of subjects were substantially CREB deficient while they had constitutively high activity of MAP kinase (Erk-1/2). In comparison to normal controls (n=7), the median level of total CREB protein by ELISA was significantly lower in JMML subjects (0.62 vs 8.85 ng/mg BSA in normal controls; p=0.006). The mechanism that causes CREB deficiency in JMML is under further investigation and further results may be available to present at the meeting. This is the first evidence that CREB, a critical component downstream of the GM-CSF receptor, is highly deficient in the majority of JMML cases. Disclosures: No relevant conflicts of interest to declare.

Using Small Molecules To Identify Critical Signaling Pathways Of Mutant N-RAS In Acute Leukemia Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 169-169
Author(s):  
Atsushi Nonami ◽  
Martin Sattler ◽  
Ellen L. Weisberg ◽  
Jianming Zhang ◽  
Qingsong Liu ◽  
...  
Keyword(s):  
Small Molecules ◽  
Signaling Pathways ◽  
Small Molecule ◽  
Leukemic Cells ◽  
Leukemia Cells ◽  
Ras Signaling ◽  
Over Expression ◽  
Simultaneous Inhibition ◽  
Chemical Screen ◽  
Multiple Signaling

Abstract Activating point mutations in NRAS are detected in more than 10% of AML patients, making NRAS an important therapeutic target. Using small molecules to directly target NRAS or inhibit post-translational modification, such as farnesylation, have been extensively investigated. The potential of strategies focused on targeting downstream effectors of RAS, such as RAF or MEK, has been limited by the complexity of RAS signaling, including redundancy and feedback loops. Large-scale RNAi screens have been used to identify genes (TBK1, STK33 and GATA2, for example) that are synthetically lethal with RAS mutations and these are being explored as therapeutic targets. Recognizing the complexity of RAS signaling, we tested the notion that small molecule screens designed to simultaneously inhibit multiple signaling pathways might identify combinations of pathways that are critical for NRAS signaling in leukemic cells. Initially, we created an experimental Ba/F3 cell line model that was completely dependent on oncogenic N-RAS-G12D for growth and survival. Knockdown of NRAS suppressed growth >95%, but could be rescued by interleukin-3 (IL-3). A chemical screen using panels of multi-targeted small molecule kinase inhibitors against BaF3-NRAS-G12D cells revealed a lead compound, NRAS1 (N-(4-methyl-3-(1-methyl-7-(6-methylpyridin-3-ylamino)-2-oxo-1,2-dihydropyrimido[4,5-d]pyrimidin-3(4H)-yl)phenyl)-3-(trifluoromethyl)benzamide), with high selectivity and sensitivity toward leukemia cell lines with NRAS mutations in vitro. A number of studies were then performed to investigate the targets of this compound. Transcriptional profiling before and after treatment of two AML cell lines with NRAS mutation (OCI-AML3 and KO52 cells, respectively) showed profiles similar to that obtained by knocking down NRAS, supporting the hypothesis that this compound suppressed NRAS signaling. Biochemical studies demonstrated that NRAS1 did not inhibit several classical targets of RAS signaling, including, RAF, MEK and ERK. In contrast, NRAS1 was found to substantially reduce AKT and RPS6 phosphorylation. Over-expression of a constitutively active allele of AKT, myrAKT, in Ba/F3-NRAS G12D cells conferred strong resistance to NRAS1, confirming that suppression of phospho-AKT may be important for the function of NRAS1. However, direct inhibition of AKT only partially recapitulated the effects of NRAS1. Kinase selectivity profiling of NRAS1 (1μM) in OCI-AML3 cells (EC50: 0.3μM) identified 13 major binding partners with more than 85% efficacy. The targets consisted mainly of SRC family proteins (ie SRC, FGR, and LYN) and MAPK family proteins (ie GCK, KSH, and p38), but not MEK1/2, ERK1/2 or AKT1-3. A series of analogs of NRAS1 was synthesized and structure/function studies were carried out. One compound, (LKB-0304601, 1% EC50 of original compound) lost the ability to bind to the MAP4K family of proteins, especially GCK (MAPK4K2). A combination effect was observed between a known GCK inhibitor, NG25, and a known allosteric AKT inhibitor, MK-2206, against mutant NRAS-expressing cells. This finding supports the hypothesis that simultaneous inhibition of GCK and AKT has suppressive activity against leukemia cells transformed by NRAS. Furthermore, a putative gate-keeper mutation introduced into GCK (GCK G96S) resulted in partial resistance to growth suppression by NG25 or NRAS1. Growth suppression of NRAS-transformed leukemic cells was further induced by knock-down of GCK by shRNAs in cells with mutant NRAS, THP-1 cells and MOLT-3, and this effect could be rescued by over-expression of GCK. Finally, in a xenotransplant model using NRAS-mutant-expressing OCI-AML3 cells and MOLT-3 cells, NRAS1 significantly reduced tumor burden and prolonged survival compared to controls. Overall, by using a chemical screen designed to inhibit multiple signaling pathways simultaneously in oncogene-addicted cells, followed by signaling studies, cell biological studies and kinase selectivity profiling, we found that simultaneous inhibition of AKT and GCK, by either NRAS1 or selective inhibitors, exhibits activity against NRAS-transformed leukemia cells. Disclosures: Griffin: Novartis Pharmaceuticals: Research Funding.

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